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Sample records for bio-inspired computing tissues

  1. Bio-inspired computation in telecommunications

    CERN Document Server

    Yang, Xin-She; Ting, TO

    2015-01-01

    Bio-inspired computation, especially those based on swarm intelligence, has become increasingly popular in the last decade. Bio-Inspired Computation in Telecommunications reviews the latest developments in bio-inspired computation from both theory and application as they relate to telecommunications and image processing, providing a complete resource that analyzes and discusses the latest and future trends in research directions. Written by recognized experts, this is a must-have guide for researchers, telecommunication engineers, computer scientists and PhD students.

  2. Bio-inspired computation in unmanned aerial vehicles

    CERN Document Server

    Duan, Haibin

    2014-01-01

    Bio-inspired Computation in Unmanned Aerial Vehicles focuses on the aspects of path planning, formation control, heterogeneous cooperative control and vision-based surveillance and navigation in Unmanned Aerial Vehicles (UAVs) from the perspective of bio-inspired computation. It helps readers to gain a comprehensive understanding of control-related problems in UAVs, presenting the latest advances in bio-inspired computation. By combining bio-inspired computation and UAV control problems, key questions are explored in depth, and each piece is content-rich while remaining accessible. With abundant illustrations of simulation work, this book links theory, algorithms and implementation procedures, demonstrating the simulation results with graphics that are intuitive without sacrificing academic rigor. Further, it pays due attention to both the conceptual framework and the implementation procedures. The book offers a valuable resource for scientists, researchers and graduate students in the field of Control, Aeros...

  3. Advances in bio-inspired computing for combinatorial optimization problems

    CERN Document Server

    Pintea, Camelia-Mihaela

    2013-01-01

    Advances in Bio-inspired Combinatorial Optimization Problems' illustrates several recent bio-inspired efficient algorithms for solving NP-hard problems.Theoretical bio-inspired concepts and models, in particular for agents, ants and virtual robots are described. Large-scale optimization problems, for example: the Generalized Traveling Salesman Problem and the Railway Traveling Salesman Problem, are solved and their results are discussed.Some of the main concepts and models described in this book are: inner rule to guide ant search - a recent model in ant optimization, heterogeneous sensitive a

  4. 7th International Conference on Bio-Inspired Computing : Theories and Applications

    CERN Document Server

    Singh, Pramod; Deep, Kusum; Pant, Millie; Nagar, Atulya

    2013-01-01

    The book is a collection of high quality peer reviewed research papers presented in Seventh International Conference on Bio-Inspired Computing (BIC-TA 2012) held at ABV-IIITM Gwalior, India. These research papers provide the latest developments in the broad area of "Computational Intelligence". The book discusses wide variety of industrial, engineering and scientific applications of nature/bio-inspired computing and presents invited papers from the inventors/originators of novel computational techniques.

  5. Fifth International Conference on Innovations in Bio-Inspired Computing and Applications

    CERN Document Server

    Abraham, Ajith; Snášel, Václav

    2014-01-01

    This volume of Advances in Intelligent Systems and Computing contains accepted papers presented at IBICA2014, the 5th International Conference on Innovations in Bio-inspired Computing and Applications. The aim of IBICA 2014 was to provide a platform for world research leaders and practitioners, to discuss the full spectrum of current theoretical developments, emerging technologies, and innovative applications of Bio-inspired Computing. Bio-inspired Computing remains to be one of the most exciting research areas, and it is continuously demonstrating exceptional strength in solving complex real life problems. The main driving force of the conference was to further explore the intriguing potential of Bio-inspired Computing. IBICA 2014 was held in Ostrava, Czech Republic and hosted by the VSB - Technical University of Ostrava.

  6. 4th International Conference on Innovations in Bio-Inspired Computing and Applications

    CERN Document Server

    Krömer, Pavel; Snášel, Václav

    2014-01-01

    This volume of Advances in Intelligent Systems and Computing contains accepted papers presented at IBICA2013, the 4th International Conference on Innovations in Bio-inspired Computing and Applications. The aim of IBICA 2013 was to provide a platform for world research leaders and practitioners, to discuss the full spectrum of current theoretical developments, emerging technologies, and innovative applications of Bio-inspired Computing. Bio-inspired Computing is currently one of the most exciting research areas, and it is continuously demonstrating exceptional strength in solving complex real life problems. The main driving force of the conference is to further explore the intriguing potential of Bio-inspired Computing. IBICA 2013 was held in Ostrava, Czech Republic and hosted by the VSB - Technical University of Ostrava.

  7. 6th International Conference on Innovations in Bio-Inspired Computing and Applications

    CERN Document Server

    Abraham, Ajith; Krömer, Pavel; Pant, Millie; Muda, Azah

    2016-01-01

    This Volume contains the papers presented during the 6th International Conference on Innovations in Bio-Inspired Computing and Applications IBICA 2015 which was held in Kochi, India during December 16-18, 2015. The 51 papers presented in this Volume were carefully reviewed and selected. The 6th International Conference IBICA 2015 has been organized to discuss the state-of-the-art as well as to address various issues in the growing research field of Bio-inspired Computing which is currently one of the most exciting research areas, and is continuously demonstrating exceptional strength in solving complex real life problems. The Volume will be a valuable reference to researchers, students and practitioners in the computational intelligence field.

  8. Bio-inspired networking

    CERN Document Server

    Câmara, Daniel

    2015-01-01

    Bio-inspired techniques are based on principles, or models, of biological systems. In general, natural systems present remarkable capabilities of resilience and adaptability. In this book, we explore how bio-inspired methods can solve different problems linked to computer networks. Future networks are expected to be autonomous, scalable and adaptive. During millions of years of evolution, nature has developed a number of different systems that present these and other characteristics required for the next generation networks. Indeed, a series of bio-inspired methods have been successfully used to solve the most diverse problems linked to computer networks. This book presents some of these techniques from a theoretical and practical point of view. Discusses the key concepts of bio-inspired networking to aid you in finding efficient networking solutions Delivers examples of techniques both in theoretical concepts and practical applications Helps you apply nature's dynamic resource and task management to your co...

  9. Prediction of Software Reliability using Bio Inspired Soft Computing Techniques.

    Science.gov (United States)

    Diwaker, Chander; Tomar, Pradeep; Poonia, Ramesh C; Singh, Vijander

    2018-04-10

    A lot of models have been made for predicting software reliability. The reliability models are restricted to using particular types of methodologies and restricted number of parameters. There are a number of techniques and methodologies that may be used for reliability prediction. There is need to focus on parameters consideration while estimating reliability. The reliability of a system may increase or decreases depending on the selection of different parameters used. Thus there is need to identify factors that heavily affecting the reliability of the system. In present days, reusability is mostly used in the various area of research. Reusability is the basis of Component-Based System (CBS). The cost, time and human skill can be saved using Component-Based Software Engineering (CBSE) concepts. CBSE metrics may be used to assess those techniques which are more suitable for estimating system reliability. Soft computing is used for small as well as large-scale problems where it is difficult to find accurate results due to uncertainty or randomness. Several possibilities are available to apply soft computing techniques in medicine related problems. Clinical science of medicine using fuzzy-logic, neural network methodology significantly while basic science of medicine using neural-networks-genetic algorithm most frequently and preferably. There is unavoidable interest shown by medical scientists to use the various soft computing methodologies in genetics, physiology, radiology, cardiology and neurology discipline. CBSE boost users to reuse the past and existing software for making new products to provide quality with a saving of time, memory space, and money. This paper focused on assessment of commonly used soft computing technique like Genetic Algorithm (GA), Neural-Network (NN), Fuzzy Logic, Support Vector Machine (SVM), Ant Colony Optimization (ACO), Particle Swarm Optimization (PSO), and Artificial Bee Colony (ABC). This paper presents working of soft computing

  10. 8th International Conference on Bio-Inspired Computing : Theories and Applications

    CERN Document Server

    Pan, Linqiang; Fang, Xianwen

    2013-01-01

    International Conference on Bio-Inspired Computing: Theories and Applications (BIC-TA) is one of the flagship conferences on Bio-Computing, bringing together the world’s leading scientists from different areas of Natural Computing. Since 2006, the conferences have taken place at Wuhan (2006), Zhengzhou (2007), Adelaide (2008), Beijing (2009), Liverpool & Changsha (2010), Malaysia (2011) and India (2012). Following the successes of previous events, the 8th conference is organized and hosted by Anhui University of Science and Technology in China. This conference aims to provide a high-level international forum that researchers with different backgrounds and who are working in the related areas can use to present their latest results and exchange ideas. Additionally, the growing trend in Emergent Systems has resulted in the inclusion of two other closely related fields in the BIC-TA 2013 event, namely Complex Systems and Computational Neuroscience. These proceedings are intended for researchers in the fiel...

  11. Parallel Processing and Bio-inspired Computing for Biomedical Image Registration

    Directory of Open Access Journals (Sweden)

    Silviu Ioan Bejinariu

    2014-07-01

    Full Text Available Image Registration (IR is an optimization problem computing optimal parameters of a geometric transform used to overlay one or more source images to a given model by maximizing a similarity measure. In this paper the use of bio-inspired optimization algorithms in image registration is analyzed. Results obtained by means of three different algorithms are compared: Bacterial Foraging Optimization Algorithm (BFOA, Genetic Algorithm (GA and Clonal Selection Algorithm (CSA. Depending on the images type, the registration may be: area based, which is slow but more precise, and features based, which is faster. In this paper a feature based approach based on the Scale Invariant Feature Transform (SIFT is proposed. Finally, results obtained using sequential and parallel implementations on multi-core systems for area based and features based image registration are compared.

  12. Computational Design of Multi-component Bio-Inspired Bilayer Membranes

    Directory of Open Access Journals (Sweden)

    Evan Koufos

    2014-04-01

    Full Text Available Our investigation is motivated by the need to design bilayer membranes with tunable interfacial and mechanical properties for use in a range of applications, such as targeted drug delivery, sensing and imaging. We draw inspiration from biological cell membranes and focus on their principal constituents. In this paper, we present our results on the role of molecular architecture on the interfacial, structural and dynamical properties of bio-inspired membranes. We focus on four lipid architectures with variations in the head group shape and the hydrocarbon tail length. Each lipid species is composed of a hydrophilic head group and two hydrophobic tails. In addition, we study a model of the Cholesterol molecule to understand the interfacial properties of a bilayer membrane composed of rigid, single-tail molecular species. We demonstrate the properties of the bilayer membranes to be determined by the molecular architecture and rigidity of the constituent species. Finally, we demonstrate the formation of a stable mixed bilayer membrane composed of Cholesterol and one of the phospholipid species. Our approach can be adopted to design multi-component bilayer membranes with tunable interfacial and mechanical properties. We use a Molecular Dynamics-based mesoscopic simulation technique called Dissipative Particle Dynamics that resolves the molecular details of the components through soft-sphere coarse-grained models and reproduces the hydrodynamic behavior of the system over extended time scales.

  13. A bio-inspired swellable microneedle adhesive for mechanical interlocking with tissue

    Science.gov (United States)

    Yang, Seung Yun; O'Cearbhaill, Eoin D.; Sisk, Geoffroy C.; Park, Kyeng Min; Cho, Woo Kyung; Villiger, Martin; Bouma, Brett E.; Pomahac, Bohdan; Karp, Jeffrey M.

    2013-04-01

    Achieving significant adhesion to soft tissues while minimizing tissue damage poses a considerable clinical challenge. Chemical-based adhesives require tissue-specific reactive chemistry, typically inducing a significant inflammatory response. Staples are fraught with limitations including high-localized tissue stress and increased risk of infection, and nerve and blood vessel damage. Here inspired by the endoparasite Pomphorhynchus laevis, which swells its proboscis to attach to its host’s intestinal wall, we have developed a biphasic microneedle array that mechanically interlocks with tissue through swellable microneedle tips, achieving ~3.5-fold increase in adhesion strength compared with staples in skin graft fixation, and removal force of ~4.5 N cm-2 from intestinal mucosal tissue. Comprising a poly(styrene)-block-poly(acrylic acid) swellable tip and non-swellable polystyrene core, conical microneedles penetrate tissue with minimal insertion force and depth, yet high adhesion strength in their swollen state. Uniquely, this design provides universal soft tissue adhesion with minimal damage, less traumatic removal, reduced risk of infection and delivery of bioactive therapeutics.

  14. A novel angle computation and calibration algorithm of bio-inspired sky-light polarization navigation sensor.

    Science.gov (United States)

    Xian, Zhiwen; Hu, Xiaoping; Lian, Junxiang; Zhang, Lilian; Cao, Juliang; Wang, Yujie; Ma, Tao

    2014-09-15

    Navigation plays a vital role in our daily life. As traditional and commonly used navigation technologies, Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS) can provide accurate location information, but suffer from the accumulative error of inertial sensors and cannot be used in a satellite denied environment. The remarkable navigation ability of animals shows that the pattern of the polarization sky can be used for navigation. A bio-inspired POLarization Navigation Sensor (POLNS) is constructed to detect the polarization of skylight. Contrary to the previous approach, we utilize all the outputs of POLNS to compute input polarization angle, based on Least Squares, which provides optimal angle estimation. In addition, a new sensor calibration algorithm is presented, in which the installation angle errors and sensor biases are taken into consideration. Derivation and implementation of our calibration algorithm are discussed in detail. To evaluate the performance of our algorithms, simulation and real data test are done to compare our algorithms with several exiting algorithms. Comparison results indicate that our algorithms are superior to the others and are more feasible and effective in practice.

  15. Bio-inspired vision

    International Nuclear Information System (INIS)

    Posch, C

    2012-01-01

    Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980's, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ''neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems

  16. Anomalous Diffusion within the Transcriptome as a Bio-Inspired Computing Framework for Resilience

    Directory of Open Access Journals (Sweden)

    William Seffens

    2017-07-01

    Full Text Available Much of biology-inspired computer science is based on the Central Dogma, as implemented with genetic algorithms or evolutionary computation. That 60-year-old biological principle based on the genome, transcriptome and proteasome is becoming overshadowed by a new paradigm of complex ordered associations and connections between layers of biological entities, such as interactomes, metabolomics, etc. We define a new hierarchical concept as the “Connectosome”, and propose new venues of computational data structures based on a conceptual framework called “Grand Ensemble” which contains the Central Dogma as a subset. Connectedness and communication within and between living or biology-inspired systems comprise ensembles from which a physical computing system can be conceived. In this framework the delivery of messages is filtered by size and a simple and rapid semantic analysis of their content. This work aims to initiate discussion on the Grand Ensemble in network biology as a representation of a Persistent Turing Machine. This framework adding interaction and persistency to the classic Turing-machine model uses metrics based on resilience that has application to dynamic optimization problem solving in Genetic Programming.

  17. Bio-inspired computational heuristics to study Lane-Emden systems arising in astrophysics model.

    Science.gov (United States)

    Ahmad, Iftikhar; Raja, Muhammad Asif Zahoor; Bilal, Muhammad; Ashraf, Farooq

    2016-01-01

    This study reports novel hybrid computational methods for the solutions of nonlinear singular Lane-Emden type differential equation arising in astrophysics models by exploiting the strength of unsupervised neural network models and stochastic optimization techniques. In the scheme the neural network, sub-part of large field called soft computing, is exploited for modelling of the equation in an unsupervised manner. The proposed approximated solutions of higher order ordinary differential equation are calculated with the weights of neural networks trained with genetic algorithm, and pattern search hybrid with sequential quadratic programming for rapid local convergence. The results of proposed solvers for solving the nonlinear singular systems are in good agreements with the standard solutions. Accuracy and convergence the design schemes are demonstrated by the results of statistical performance measures based on the sufficient large number of independent runs.

  18. Combining Bio-inspired Sensing with Bio-inspired Locomotion

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    In this paper we present a preliminary Braitenberg vehicle–like approach to combine bio-inspired audition with bio-inspired quadruped locomotion in simulation. Locomotion gaits of the salamander–like robot Salamandra robotica are modified by a lizard’s peripheral auditory system model that modula......In this paper we present a preliminary Braitenberg vehicle–like approach to combine bio-inspired audition with bio-inspired quadruped locomotion in simulation. Locomotion gaits of the salamander–like robot Salamandra robotica are modified by a lizard’s peripheral auditory system model...

  19. Quality-of-service sensitivity to bio-inspired/evolutionary computational methods for intrusion detection in wireless ad hoc multimedia sensor networks

    Science.gov (United States)

    Hortos, William S.

    2012-06-01

    In the author's previous work, a cross-layer protocol approach to wireless sensor network (WSN) intrusion detection an identification is created with multiple bio-inspired/evolutionary computational methods applied to the functions of the protocol layers, a single method to each layer, to improve the intrusion-detection performance of the protocol over that of one method applied to only a single layer's functions. The WSN cross-layer protocol design embeds GAs, anti-phase synchronization, ACO, and a trust model based on quantized data reputation at the physical, MAC, network, and application layer, respectively. The construct neglects to assess the net effect of the combined bioinspired methods on the quality-of-service (QoS) performance for "normal" data streams, that is, streams without intrusions. Analytic expressions of throughput, delay, and jitter, coupled with simulation results for WSNs free of intrusion attacks, are the basis for sensitivity analyses of QoS metrics for normal traffic to the bio-inspired methods.

  20. Bio-inspired fabrication of fibroin cryogels from the muga silkworm Antheraea assamensis for liver tissue engineering

    International Nuclear Information System (INIS)

    Kundu, Banani; Kundu, S C

    2013-01-01

    Conventional scaffold fabrication techniques result in narrow pore architectures causing a limited interconnectivity and use of porogens, which affects the bio- or cyto-compatibility. To ameliorate this, cryogels are immensely explored due to their macro-porous nature, ease in fabrication, using ice crystals as porogens, the shape property, easy reproducibility and cost-effective fabrication technique. Cryogels in the present study are prepared from nonmulberry Indian muga silk gland protein fibroin of Antheraea assamensis using two different fabrication temperatures (−20 and −80 °C). Anionic surfactant sodium dodecyl sulfate is used to solubilize fibroin, which in turn facilitates gelation by accelerating the ß-sheet formation. Ethanol is employed to stabilize the 3D network and induces bimodal porosity. The gels thus formed demonstrate increased ß-sheet content (FTIR) and a considerable effect of pre-freezing temperatures on 3D micro-architectures. The cryogels are capable of absorbing large amounts of water and withstanding mechanical compression without structure deformation. Further, cell impregnated cryogels well support the viability of human hepatocarcinoma cells (live/dead assay). The formation of cellular aggregates (confocal laser and scanning electron microscope), derivation in metabolic activity and proliferation rate are obtained in constructs fabricated at different temperatures. In summary, the present work reveals promising insights in the development of a biomimetic functional template for biomedical therapeutics and liver tissue engineering. (paper)

  1. Bio-inspired varying subspace based computational framework for a class of nonlinear constrained optimal trajectory planning problems.

    Science.gov (United States)

    Xu, Y; Li, N

    2014-09-01

    Biological species have produced many simple but efficient rules in their complex and critical survival activities such as hunting and mating. A common feature observed in several biological motion strategies is that the predator only moves along paths in a carefully selected or iteratively refined subspace (or manifold), which might be able to explain why these motion strategies are effective. In this paper, a unified linear algebraic formulation representing such a predator-prey relationship is developed to simplify the construction and refinement process of the subspace (or manifold). Specifically, the following three motion strategies are studied and modified: motion camouflage, constant absolute target direction and local pursuit. The framework constructed based on this varying subspace concept could significantly reduce the computational cost in solving a class of nonlinear constrained optimal trajectory planning problems, particularly for the case with severe constraints. Two non-trivial examples, a ground robot and a hypersonic aircraft trajectory optimization problem, are used to show the capabilities of the algorithms in this new computational framework.

  2. Bio-inspired varying subspace based computational framework for a class of nonlinear constrained optimal trajectory planning problems

    International Nuclear Information System (INIS)

    Xu, Y; Li, N

    2014-01-01

    Biological species have produced many simple but efficient rules in their complex and critical survival activities such as hunting and mating. A common feature observed in several biological motion strategies is that the predator only moves along paths in a carefully selected or iteratively refined subspace (or manifold), which might be able to explain why these motion strategies are effective. In this paper, a unified linear algebraic formulation representing such a predator–prey relationship is developed to simplify the construction and refinement process of the subspace (or manifold). Specifically, the following three motion strategies are studied and modified: motion camouflage, constant absolute target direction and local pursuit. The framework constructed based on this varying subspace concept could significantly reduce the computational cost in solving a class of nonlinear constrained optimal trajectory planning problems, particularly for the case with severe constraints. Two non-trivial examples, a ground robot and a hypersonic aircraft trajectory optimization problem, are used to show the capabilities of the algorithms in this new computational framework. (paper)

  3. Switchable bio-inspired adhesives

    Science.gov (United States)

    Kroner, Elmar

    2015-03-01

    Geckos have astonishing climbing abilities. They can adhere to almost any surface and can run on walls and even stick to ceilings. The extraordinary adhesion performance is caused by a combination of a complex surface pattern on their toes and the biomechanics of its movement. These biological dry adhesives have been intensely investigated during recent years because of the unique combination of adhesive properties. They provide high adhesion, allow for easy detachment, can be removed residue-free, and have self-cleaning properties. Many aspects have been successfully mimicked, leading to artificial, bio-inspired, patterned dry adhesives, and were addressed and in some aspects they even outperform the adhesion capabilities of geckos. However, designing artificial patterned adhesion systems with switchable adhesion remains a big challenge; the gecko's adhesion system is based on a complex hierarchical surface structure and on advanced biomechanics, which are both difficult to mimic. In this paper, two approaches are presented to achieve switchable adhesion. The first approach is based on a patterned polydimethylsiloxane (PDMS) polymer, where adhesion can be switched on and off by applying a low and a high compressive preload. The switch in adhesion is caused by a reversible mechanical instability of the adhesive silicone structures. The second approach is based on a composite material consisting of a Nickel- Titanium (NiTi) shape memory alloy and a patterned adhesive PDMS layer. The NiTi alloy is trained to change its surface topography as a function of temperature, which results in a change of the contact area and of alignment of the adhesive pattern towards a substrate, leading to switchable adhesion. These examples show that the unique properties of bio-inspired adhesives can be greatly improved by new concepts such as mechanical instability or by the use of active materials which react to external stimuli.

  4. Bio-inspired dental fillings

    Science.gov (United States)

    Deyhle, Hans; Bunk, Oliver; Buser, Stefan; Krastl, Gabriel; Zitzmann, Nicola U.; Ilgenstein, Bernd; Beckmann, Felix; Pfeiffer, Franz; Weiger, Roland; Müller, Bert

    2009-08-01

    Human teeth are anisotropic composites. Dentin as the core material of the tooth consists of nanometer-sized calcium phosphate crystallites embedded in collagen fiber networks. It shows its anisotropy on the micrometer scale by its well-oriented microtubules. The detailed three-dimensional nanostructure of the hard tissues namely dentin and enamel, however, is not understood, although numerous studies on the anisotropic mechanical properties have been performed and evaluated to explain the tooth function including the enamel-dentin junction acting as effective crack barrier. Small angle X-ray scattering (SAXS) with a spatial resolution in the 10 μm range allows determining the size and orientation of the constituents on the nanometer scale with reasonable precision. So far, only some dental materials, i.e. the fiber reinforced posts exhibit anisotropic properties related to the micrometer-size glass fibers. Dental fillings, composed of nanostructures oriented similar to the natural hard tissues of teeth, however, do not exist at all. The current X-ray-based investigations of extracted human teeth provide evidence for oriented micro- and nanostructures in dentin and enamel. These fundamental quantitative findings result in profound knowledge to develop biologically inspired dental fillings with superior resistance to thermal and mechanical shocks.

  5. A bio-inspired, microchanneled hydrogel with controlled spacing of cell adhesion ligands regulates 3D spatial organization of cells and tissue.

    Science.gov (United States)

    Lee, Min Kyung; Rich, Max H; Lee, Jonghwi; Kong, Hyunjoon

    2015-07-01

    Bioactive hydrogels have been extensively studied as a platform for 3D cell culture and tissue regeneration. One of the key desired design parameters is the ability to control spatial organization of biomolecules and cells and subsequent tissue in a 3D matrix. To this end, this study presents a simple but advanced method to spatially organize microchanneled, cell adherent gel blocks and non-adherent ones in a single construct. This hydrogel system was prepared by first fabricating a bimodal hydrogel in which the microscale, alginate gel blocks modified with cell adhesion peptides containing Arg-Gly-Asp sequence (RGD peptides), and those free of RGD peptides, were alternatingly presented. Then, anisotropically aligned microchannels were introduced by uniaxial freeze-drying of the bimodal hydrogel. The resulting gel system could drive bone marrow stromal cells to adhere to and differentiate into neuron and glial cells exclusively in microchannels of the alginate gel blocks modified with RGD peptides. Separately, the bimodal gel loaded with microparticles releasing vascular endothelial growth factor stimulated vascular growth solely into microchannels of the RGD-alginate gel blocks in vivo. These results were not attained by the bimodal hydrogel fabricated to present randomly oriented micropores. Overall, the bimodal gel system could regulate spatial organization of nerve-like tissue or blood vessels at sub-micrometer length scale. We believe that the hydrogel assembly demonstrated in this study will be highly useful in developing a better understanding of diverse cellular behaviors in 3D tissue and further improve quality of a wide array of engineered tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Bio-Inspired Cyber Security for Smart Grid Deployments

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, Archibald D.; Thompson, Seth R.; Doroshchuk, Ruslan A.; Fink, Glenn A.; Fulp, Errin W.

    2013-05-01

    mart grid technologies are transforming the electric power grid into a grid with bi-directional flows of both power and information. Operating millions of new smart meters and smart appliances will significantly impact electric distribution systems resulting in greater efficiency. However, the scale of the grid and the new types of information transmitted will potentially introduce several security risks that cannot be addressed by traditional, centralized security techniques. We propose a new bio-inspired cyber security approach. Social insects, such as ants and bees, have developed complex-adaptive systems that emerge from the collective application of simple, light-weight behaviors. The Digital Ants framework is a bio-inspired framework that uses mobile light-weight agents. Sensors within the framework use digital pheromones to communicate with each other and to alert each other of possible cyber security issues. All communication and coordination is both localized and decentralized thereby allowing the framework to scale across the large numbers of devices that will exist in the smart grid. Furthermore, the sensors are light-weight and therefore suitable for implementation on devices with limited computational resources. This paper will provide a brief overview of the Digital Ants framework and then present results from test bed-based demonstrations that show that Digital Ants can identify a cyber attack scenario against smart meter deployments.

  7. Molecular machines with bio-inspired mechanisms.

    Science.gov (United States)

    Zhang, Liang; Marcos, Vanesa; Leigh, David A

    2018-02-26

    The widespread use of molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular machines-which by and large function as switches-and the machines of the macroscopic world, which utilize the synchronized behavior of integrated components to perform more sophisticated tasks than is possible with any individual switch. Should we try to make molecular machines of greater complexity by trying to mimic machines from the macroscopic world or instead apply unfamiliar (and no doubt have to discover or invent currently unknown) mechanisms utilized by biological machines? Here we try to answer that question by exploring some of the advances made to date using bio-inspired machine mechanisms.

  8. Bio-Inspired Optimization of Sustainable Energy Systems: A Review

    Directory of Open Access Journals (Sweden)

    Yu-Jun Zheng

    2013-01-01

    Full Text Available Sustainable energy development always involves complex optimization problems of design, planning, and control, which are often computationally difficult for conventional optimization methods. Fortunately, the continuous advances in artificial intelligence have resulted in an increasing number of heuristic optimization methods for effectively handling those complicated problems. Particularly, algorithms that are inspired by the principles of natural biological evolution and/or collective behavior of social colonies have shown a promising performance and are becoming more and more popular nowadays. In this paper we summarize the recent advances in bio-inspired optimization methods, including artificial neural networks, evolutionary algorithms, swarm intelligence, and their hybridizations, which are applied to the field of sustainable energy development. Literature reviewed in this paper shows the current state of the art and discusses the potential future research trends.

  9. Bio-inspired Autonomic Structures: a middleware for Telecommunications Ecosystems

    Science.gov (United States)

    Manzalini, Antonio; Minerva, Roberto; Moiso, Corrado

    Today, people are making use of several devices for communications, for accessing multi-media content services, for data/information retrieving, for processing, computing, etc.: examples are laptops, PDAs, mobile phones, digital cameras, mp3 players, smart cards and smart appliances. One of the most attracting service scenarios for future Telecommunications and Internet is the one where people will be able to browse any object in the environment they live: communications, sensing and processing of data and services will be highly pervasive. In this vision, people, machines, artifacts and the surrounding space will create a kind of computational environment and, at the same time, the interfaces to the network resources. A challenging technological issue will be interconnection and management of heterogeneous systems and a huge amount of small devices tied together in networks of networks. Moreover, future network and service infrastructures should be able to provide Users and Application Developers (at different levels, e.g., residential Users but also SMEs, LEs, ASPs/Web2.0 Service roviders, ISPs, Content Providers, etc.) with the most appropriate "environment" according to their context and specific needs. Operators must be ready to manage such level of complication enabling their latforms with technological advanced allowing network and services self-supervision and self-adaptation capabilities. Autonomic software solutions, enhanced with innovative bio-inspired mechanisms and algorithms, are promising areas of long term research to face such challenges. This chapter proposes a bio-inspired autonomic middleware capable of leveraging the assets of the underlying network infrastructure whilst, at the same time, supporting the development of future Telecommunications and Internet Ecosystems.

  10. Catalytic applications of bio-inspired nanomaterials

    Science.gov (United States)

    Pacardo, Dennis Kien Balaong

    The biomimetic synthesis of Pd nanoparticles was presented using the Pd4 peptide, TSNAVHPTLRHL, isolated from combinatorial phage display library. Using this approach, nearly monodisperse and spherical Pd nanoparticles were generated with an average diameter of 1.9 +/- 0.4 nm. The peptide-based nanocatalyst were employed in the Stille coupling reaction under energy-efficient and environmentally friendly reaction conditions of aqueous solvent, room temperature and very low catalyst loading. To this end, the Pd nanocatalyst generated high turnover frequency (TOF) value and quantitative yields using ≥ 0.005 mol% Pd as well as catalytic activities with different aryl halides containing electron-withdrawing and electron-donating groups. The Pd4-capped Pd nanoparticles followed the atom-leaching mechanism and were found to be selective with respect to substrate identity. On the other hand, the naturally-occurring R5 peptide (SSKKSGSYSGSKGSKRRIL) was employed in the synthesis of biotemplated Pd nanomaterials which showed morphological changes as a function of Pd:peptide ratio. TOF analysis for hydrogenation of olefinic alcohols showed similar catalytic activity regardless of nanomorphology. Determination of catalytic properties of these bio-inspired nanomaterials are important as they serve as model system for alternative green catalyst with applications in industrially important transformations.

  11. Bio-inspired Design Approached Antifouling Strategies

    Science.gov (United States)

    Fitzsimons, L.; Chapman, J.; Lawlor, A.; Regan, F.

    2012-04-01

    Biofouling exists as the undesirable accumulation of flora and fauna on a given substrate when immersed into an aquatic media. Its presence causes a range of deleterious effects for anyone faced in tackling the problem, which is more than often financially testing. Generally, the initial biofouling stage is stochastic and the attachment of microorganisms held fast in biofilm matrices is irreversible. Stability of the biofilm occurs when exopolymeric substances (EPS) are produced forming a protective surrounding, allowing the cohered microorganisms to colonise and thrive upon the surface. Therefore, if this initial stage of biofilm development can be prevented then it could be possible to prevent subsequent macro events that ensue. Environmental monitoring is one area that faces this challenge and forms the impetus of the work presented herein. In order to improve a monitoring device's lifetime, surface coatings with biocidal agents are applied to counteract these steps. This work shows the development of a range of novel materials, which demonstrate the ability to counteract and inhibit the initial stages of biofouling for monitoring devices. Natural bio-inspired surfaces have been developed using nano-functionalised coatings. All materials are tested in the field and positive results in reducing the biofouling challenge are demonstrated. The results from the deployment of antifouling materials, together with real-time, long-term water quality data from the test site are also shown.

  12. Optic flow estimation on trajectories generated by bio-inspired closed-loop flight.

    Science.gov (United States)

    Shoemaker, Patrick A; Hyslop, Andrew M; Humbert, J Sean

    2011-05-01

    We generated panoramic imagery by simulating a fly-like robot carrying an imaging sensor, moving in free flight through a virtual arena bounded by walls, and containing obstructions. Flight was conducted under closed-loop control by a bio-inspired algorithm for visual guidance with feedback signals corresponding to the true optic flow that would be induced on an imager (computed by known kinematics and position of the robot relative to the environment). The robot had dynamics representative of a housefly-sized organism, although simplified to two-degree-of-freedom flight to generate uniaxial (azimuthal) optic flow on the retina in the plane of travel. Surfaces in the environment contained images of natural and man-made scenes that were captured by the moving sensor. Two bio-inspired motion detection algorithms and two computational optic flow estimation algorithms were applied to sequences of image data, and their performance as optic flow estimators was evaluated by estimating the mutual information between outputs and true optic flow in an equatorial section of the visual field. Mutual information for individual estimators at particular locations within the visual field was surprisingly low (less than 1 bit in all cases) and considerably poorer for the bio-inspired algorithms that the man-made computational algorithms. However, mutual information between weighted sums of these signals and comparable sums of the true optic flow showed significant increases for the bio-inspired algorithms, whereas such improvement did not occur for the computational algorithms. Such summation is representative of the spatial integration performed by wide-field motion-sensitive neurons in the third optic ganglia of flies.

  13. On-chip visual perception of motion: a bio-inspired connectionist model on FPGA.

    Science.gov (United States)

    Torres-Huitzil, César; Girau, Bernard; Castellanos-Sánchez, Claudio

    2005-01-01

    Visual motion provides useful information to understand the dynamics of a scene to allow intelligent systems interact with their environment. Motion computation is usually restricted by real time requirements that need the design and implementation of specific hardware architectures. In this paper, the design of hardware architecture for a bio-inspired neural model for motion estimation is presented. The motion estimation is based on a strongly localized bio-inspired connectionist model with a particular adaptation of spatio-temporal Gabor-like filtering. The architecture is constituted by three main modules that perform spatial, temporal, and excitatory-inhibitory connectionist processing. The biomimetic architecture is modeled, simulated and validated in VHDL. The synthesis results on a Field Programmable Gate Array (FPGA) device show the potential achievement of real-time performance at an affordable silicon area.

  14. Bio-inspired color sketch for eco-friendly printing

    Science.gov (United States)

    Safonov, Ilia V.; Tolstaya, Ekaterina V.; Rychagov, Michael N.; Lee, Hokeun; Kim, Sang Ho; Choi, Donchul

    2012-01-01

    Saving of toner/ink consumption is an important task in modern printing devices. It has a positive ecological and social impact. We propose technique for converting print-job pictures to a recognizable and pleasant color sketches. Drawing a "pencil sketch" from a photo relates to a special area in image processing and computer graphics - non-photorealistic rendering. We describe a new approach for automatic sketch generation which allows to create well-recognizable sketches and to preserve partly colors of the initial picture. Our sketches contain significantly less color dots then initial images and this helps to save toner/ink. Our bio-inspired approach is based on sophisticated edge detection technique for a mask creation and multiplication of source image with increased contrast by this mask. To construct the mask we use DoG edge detection, which is a result of blending of initial image with its blurred copy through the alpha-channel, which is created from Saliency Map according to Pre-attentive Human Vision model. Measurement of percentage of saved toner and user study proves effectiveness of proposed technique for toner saving in eco-friendly printing mode.

  15. Bio-inspired nanotechnology from surface analysis to applications

    CERN Document Server

    Walsh, Tiffany

    2014-01-01

    This book focuses on the use of bio-inspired and biomimetic methods for the fabrication and activation of nanomaterials. This includes studies concerning the binding of the biomolecules to the surface of inorganic structures, structure/function relationships of the final materials, and extensive discussions on the final applications of such biomimetic materials in unique applications including energy harvesting/storage, biomedical diagnostics, and materials assembly. This book also: ·          Covers the sustainable features of bio-inspired nanotechnology ·          Includes studies on the unique applications of biomimetic materials, such as energy harvesting and biomedical diagnostics Bio-Inspired Nanotechnology: From Surface Analysis to Applications is an ideal book for researchers, students, nanomaterials engineers, bioengineers, chemists, biologists, physicists, and medical researchers.

  16. Bio-inspired nano tools for neuroscience.

    Science.gov (United States)

    Das, Suradip; Carnicer-Lombarte, Alejandro; Fawcett, James W; Bora, Utpal

    2016-07-01

    Research and treatment in the nervous system is challenged by many physiological barriers posing a major hurdle for neurologists. The CNS is protected by a formidable blood brain barrier (BBB) which limits surgical, therapeutic and diagnostic interventions. The hostile environment created by reactive astrocytes in the CNS along with the limited regeneration capacity of the PNS makes functional recovery after tissue damage difficult and inefficient. Nanomaterials have the unique ability to interface with neural tissue in the nano-scale and are capable of influencing the function of a single neuron. The ability of nanoparticles to transcend the BBB through surface modifications has been exploited in various neuro-imaging techniques and for targeted drug delivery. The tunable topography of nanofibers provides accurate spatio-temporal guidance to regenerating axons. This review is an attempt to comprehend the progress in understanding the obstacles posed by the complex physiology of the nervous system and the innovations in design and fabrication of advanced nanomaterials drawing inspiration from natural phenomenon. We also discuss the development of nanomaterials for use in Neuro-diagnostics, Neuro-therapy and the fabrication of advanced nano-devices for use in opto-electronic and ultrasensitive electrophysiological applications. The energy efficient and parallel computing ability of the human brain has inspired the design of advanced nanotechnology based computational systems. However, extensive use of nanomaterials in neuroscience also raises serious toxicity issues as well as ethical concerns regarding nano implants in the brain. In conclusion we summarize these challenges and provide an insight into the huge potential of nanotechnology platforms in neuroscience. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Exploring Creativity in the Bio-Inspired Design Process

    DEFF Research Database (Denmark)

    Anggakara, K.; Aksdal, T.; Onarheim, Balder

    2015-01-01

    The growing interest in the of field bio-inspired design has been driven by the acknowledgement that inspiration from nature can serve as a valuable source of innovation. As an emerging approach, there has been a focus on building a principled methodology to address the challenges that arise...

  18. 3D Printing of Bio-inspired surfaces

    DEFF Research Database (Denmark)

    Méndez Ribó, Macarena; Islam, Aminul

    The ability of the gecko to scurry across smooth or rough surfaces, regardless of inclination (vertical or even upside down), has been traced to the multiscale hierarchical structures of the gecko toe [1 - 3]. Considering all the strategies to manufacture bio-inspired surfaces, the most common is...

  19. Bio Inspired Algorithms in Single and Multiobjective Reliability Optimization

    DEFF Research Database (Denmark)

    Madsen, Henrik; Albeanu, Grigore; Burtschy, Bernard

    2014-01-01

    Non-traditional search and optimization methods based on natural phenomena have been proposed recently in order to avoid local or unstable behavior when run towards an optimum state. This paper describes the principles of bio inspired algorithms and reports on Migration Algorithms and Bees...

  20. Three-Dimensional-Printing of Bio-Inspired Composites

    Science.gov (United States)

    Xiang Gu, Grace; Su, Isabelle; Sharma, Shruti; Voros, Jamie L.; Qin, Zhao; Buehler, Markus J.

    2016-01-01

    Optimized for millions of years, natural materials often outperform synthetic materials due to their hierarchical structures and multifunctional abilities. They usually feature a complex architecture that consists of simple building blocks. Indeed, many natural materials such as bone, nacre, hair, and spider silk, have outstanding material properties, making them applicable to engineering applications that may require both mechanical resilience and environmental compatibility. However, such natural materials are very difficult to harvest in bulk, and may be toxic in the way they occur naturally, and therefore, it is critical to use alternative methods to fabricate materials that have material functions similar to material function as their natural counterparts for large-scale applications. Recent progress in additive manufacturing, especially the ability to print multiple materials at upper micrometer resolution, has given researchers an excellent instrument to design and reconstruct natural-inspired materials. The most advanced 3D-printer can now be used to manufacture samples to emulate their geometry and material composition with high fidelity. Its capabilities, in combination with computational modeling, have provided us even more opportunities for designing, optimizing, and testing the function of composite materials, in order to achieve composites of high mechanical resilience and reliability. In this review article, we focus on the advanced material properties of several multifunctional biological materials and discuss how the advanced 3D-printing techniques can be used to mimic their architectures and functions. Lastly, we discuss the limitations of 3D-printing, suggest possible future developments, and discuss applications using bio-inspired materials as a tool in bioengineering and other fields. PMID:26747791

  1. Three-Dimensional-Printing of Bio-Inspired Composites.

    Science.gov (United States)

    Xiang Gu, Grace; Su, Isabelle; Sharma, Shruti; Voros, Jamie L; Qin, Zhao; Buehler, Markus J

    2016-02-01

    Optimized for millions of years, natural materials often outperform synthetic materials due to their hierarchical structures and multifunctional abilities. They usually feature a complex architecture that consists of simple building blocks. Indeed, many natural materials such as bone, nacre, hair, and spider silk, have outstanding material properties, making them applicable to engineering applications that may require both mechanical resilience and environmental compatibility. However, such natural materials are very difficult to harvest in bulk, and may be toxic in the way they occur naturally, and therefore, it is critical to use alternative methods to fabricate materials that have material functions similar to material function as their natural counterparts for large-scale applications. Recent progress in additive manufacturing, especially the ability to print multiple materials at upper micrometer resolution, has given researchers an excellent instrument to design and reconstruct natural-inspired materials. The most advanced 3D-printer can now be used to manufacture samples to emulate their geometry and material composition with high fidelity. Its capabilities, in combination with computational modeling, have provided us even more opportunities for designing, optimizing, and testing the function of composite materials, in order to achieve composites of high mechanical resilience and reliability. In this review article, we focus on the advanced material properties of several multifunctional biological materials and discuss how the advanced 3D-printing techniques can be used to mimic their architectures and functions. Lastly, we discuss the limitations of 3D-printing, suggest possible future developments, and discuss applications using bio-inspired materials as a tool in bioengineering and other fields.

  2. Creating a Bio-Inspired Solution to Prevent Erosion

    Science.gov (United States)

    Reher, R.; Martinez, A.; Cola, J.; Frost, D.

    2016-12-01

    Through the study of geophysical sciences, lessons can be developed which allow for the introduction of bio-inspired design and art concepts to K-5 elementary students. Students are placed into an engineering mindset in which they must apply the concepts of bio-geotechnics to observe how we can use nature to prevent and abate erosion. Problems are staged for students using realistic engineering scenarios such as erosion prevention through biomimicry and the study of anchorage characteristics of root structures in regard to stability of soil. Specifically, a lesson is introduced where students research, learn, and present information about bio-inspired designs to understand these concepts. They lean how plant roots differ in size and shape to stabilize soil. In addition, students perform a series of hands-on experiments which demonstrate how bio-cements and roots can slow erosion.

  3. Material requirements for bio-inspired sensing systems

    Science.gov (United States)

    Biggins, Peter; Lloyd, Peter; Salmond, David; Kusterbeck, Anne

    2008-10-01

    The aim of developing bio-inspired sensing systems is to try and emulate the amazing sensitivity and specificity observed in the natural world. These capabilities have evolved, often for specific tasks, which provide the organism with an advantage in its fight to survive and prosper. Capabilities cover a wide range of sensing functions including vision, temperature, hearing, touch, taste and smell. For some functions, the capabilities of natural systems are still greater than that achieved by traditional engineering solutions; a good example being a dog's sense of smell. Furthermore, attempting to emulate aspects of biological optics, processing and guidance may lead to more simple and effective devices. A bio-inspired sensing system is much more than the sensory mechanism. A system will need to collect samples, especially if pathogens or chemicals are of interest. Other functions could include the provision of power, surfaces and receptors, structure, locomotion and control. In fact it is possible to conceive of a complete bio-inspired system concept which is likely to be radically different from more conventional approaches. This concept will be described and individual component technologies considered.

  4. Electrochemical construction of a bio-inspired micro/nano-textured structure with cell-sized microhole arrays on biomedical titanium to enhance bioactivity

    International Nuclear Information System (INIS)

    Liang, Jianhe; Song, Ran; Huang, Qiaoling; Yang, Yun; Lin, Longxiang; Zhang, Yanmei; Jiang, Pinliang; Duan, Hongping; Dong, Xiang; Lin, Changjian

    2015-01-01

    Highlights: • The bio-inspired structure mimicked mulit-level structures of natural bone. • Ordered cell-sized microhole arrays were employed as microscale structure. • High surface roughness and superhydrophilicity were achieved on the titanium surface. • The bio-inspired titanium surface showed superior ability of biomineralization. • Cell responses were enhanced on the bio-inspired micro/nano-texutred surface. - Abstract: Biomimetic surface design of medical implants is vitally crucial to improve cellular responses and the integration of tissue onto materials. In this study, a novel hierarchical cell-sized microhole array combined with a nano-network structure was fabricated on a medical titanium surface to mimic multi-level bone structure. A three-step procedure was developed as follows: 1) electrochemical self-organization of etching on titanium substrate to create highly ordered cell-sized microhole arrays, 2) suitable dual acid etching to increase the roughness of the microholes, and then 3) electrochemical anodization in a NaOH electrolyte to construct a nano-network porous titania layer on the above micro-roughened surface. The bio-inspired micro/nano-textured structure presented the enhanced wettability and superhydrophilicity. The ability of in vitro biomineralization and corrosion resistance of the bio-inspired micro/nano-textured structure were enhanced after annealing treatment. More importantly, the bio-inspired micro/nano-textured structure on the titanium surface possessed a favourable interfacial environment to enhance attachment and proliferation of human osteoblast-like MG63 cells. All of the results demonstrated that such a bio-inspired surface of micro/nano-textured porous TiO 2 is a most promising candidate for the next generation of titanium implants

  5. Bio-inspired optical rotation sensor

    Science.gov (United States)

    O'Carroll, David C.; Shoemaker, Patrick A.; Brinkworth, Russell S. A.

    2007-01-01

    Traditional approaches to calculating self-motion from visual information in artificial devices have generally relied on object identification and/or correlation of image sections between successive frames. Such calculations are computationally expensive and real-time digital implementation requires powerful processors. In contrast flies arrive at essentially the same outcome, the estimation of self-motion, in a much smaller package using vastly less power. Despite the potential advantages and a few notable successes, few neuromorphic analog VLSI devices based on biological vision have been employed in practical applications to date. This paper describes a hardware implementation in aVLSI of our recently developed adaptive model for motion detection. The chip integrates motion over a linear array of local motion processors to give a single voltage output. Although the device lacks on-chip photodetectors, it includes bias circuits to use currents from external photodiodes, and we have integrated it with a ring-array of 40 photodiodes to form a visual rotation sensor. The ring configuration reduces pattern noise and combined with the pixel-wise adaptive characteristic of the underlying circuitry, permits a robust output that is proportional to image rotational velocity over a large range of speeds, and is largely independent of either mean luminance or the spatial structure of the image viewed. In principle, such devices could be used as an element of a velocity-based servo to replace or augment inertial guidance systems in applications such as mUAVs.

  6. Complex biological and bio-inspired systems

    Energy Technology Data Exchange (ETDEWEB)

    Ecke, Robert E [Los Alamos National Laboratory

    2009-01-01

    The understanding and characterization ofthe fundamental processes of the function of biological systems underpins many of the important challenges facing American society, from the pathology of infectious disease and the efficacy ofvaccines, to the development of materials that mimic biological functionality and deliver exceptional and novel structural and dynamic properties. These problems are fundamentally complex, involving many interacting components and poorly understood bio-chemical kinetics. We use the basic science of statistical physics, kinetic theory, cellular bio-chemistry, soft-matter physics, and information science to develop cell level models and explore the use ofbiomimetic materials. This project seeks to determine how cell level processes, such as response to mechanical stresses, chemical constituents and related gradients, and other cell signaling mechanisms, integrate and combine to create a functioning organism. The research focuses on the basic physical processes that take place at different levels ofthe biological organism: the basic role of molecular and chemical interactions are investigated, the dynamics of the DNA-molecule and its phylogenetic role are examined and the regulatory networks of complex biochemical processes are modeled. These efforts may lead to early warning algorithms ofpathogen outbreaks, new bio-sensors to detect hazards from pathomic viruses to chemical contaminants. Other potential applications include the development of efficient bio-fuel alternative-energy processes and the exploration ofnovel materials for energy usages. Finally, we use the notion of 'coarse-graining,' which is a method for averaging over less important degrees of freedom to develop computational models to predict cell function and systems-level response to disease, chemical stress, or biological pathomic agents. This project supports Energy Security, Threat Reduction, and the missions of the DOE Office of Science through its efforts to

  7. RAIN: A Bio-Inspired Communication and Data Storage Infrastructure.

    Science.gov (United States)

    Monti, Matteo; Rasmussen, Steen

    2017-01-01

    We summarize the results and perspectives from a companion article, where we presented and evaluated an alternative architecture for data storage in distributed networks. We name the bio-inspired architecture RAIN, and it offers file storage service that, in contrast with current centralized cloud storage, has privacy by design, is open source, is more secure, is scalable, is more sustainable, has community ownership, is inexpensive, and is potentially faster, more efficient, and more reliable. We propose that a RAIN-style architecture could form the backbone of the Internet of Things that likely will integrate multiple current and future infrastructures ranging from online services and cryptocurrency to parts of government administration.

  8. Final Report for Bio-Inspired Approaches to Moving-Target Defense Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Glenn A.; Oehmen, Christopher S.

    2012-09-01

    This report records the work and contributions of the NITRD-funded Bio-Inspired Approaches to Moving-Target Defense Strategies project performed by Pacific Northwest National Laboratory under the technical guidance of the National Security Agency’s R6 division. The project has incorporated a number of bio-inspired cyber defensive technologies within an elastic framework provided by the Digital Ants. This project has created the first scalable, real-world prototype of the Digital Ants Framework (DAF)[11] and integrated five technologies into this flexible, decentralized framework: (1) Ant-Based Cyber Defense (ABCD), (2) Behavioral Indicators, (3) Bioinformatic Clas- sification, (4) Moving-Target Reconfiguration, and (5) Ambient Collaboration. The DAF can be used operationally to decentralize many such data intensive applications that normally rely on collection of large amounts of data in a central repository. In this work, we have shown how these component applications may be decentralized and may perform analysis at the edge. Operationally, this will enable analytics to scale far beyond current limitations while not suffering from the bandwidth or computational limitations of centralized analysis. This effort has advanced the R6 Cyber Security research program to secure digital infrastructures by developing a dynamic means to adaptively defend complex cyber systems. We hope that this work will benefit both our client’s efforts in system behavior modeling and cyber security to the overall benefit of the nation.

  9. A highly efficient sharp-interface immersed boundary method with adaptive mesh refinement for bio-inspired flow simulations

    Science.gov (United States)

    Deng, Xiaolong; Dong, Haibo

    2017-11-01

    Developing a high-fidelity, high-efficiency numerical method for bio-inspired flow problems with flow-structure interaction is important for understanding related physics and developing many bio-inspired technologies. To simulate a fast-swimming big fish with multiple finlets or fish schooling, we need fine grids and/or a big computational domain, which are big challenges for 3-D simulations. In current work, based on the 3-D finite-difference sharp-interface immersed boundary method for incompressible flows (Mittal et al., JCP 2008), we developed an octree-like Adaptive Mesh Refinement (AMR) technique to enhance the computational ability and increase the computational efficiency. The AMR is coupled with a multigrid acceleration technique and a MPI +OpenMP hybrid parallelization. In this work, different AMR layers are treated separately and the synchronization is performed in the buffer regions and iterations are performed for the convergence of solution. Each big region is calculated by a MPI process which then uses multiple OpenMP threads for further acceleration, so that the communication cost is reduced. With these acceleration techniques, various canonical and bio-inspired flow problems with complex boundaries can be simulated accurately and efficiently. This work is supported by the MURI Grant Number N00014-14-1-0533 and NSF Grant CBET-1605434.

  10. EAP artificial muscle actuators for bio-inspired intelligent social robotics (Conference Presentation)

    Science.gov (United States)

    Hanson, David F.

    2017-04-01

    Bio-inspired intelligent robots are coming of age in both research and industry, propelling market growth for robots and A.I. However, conventional motors limit bio-inspired robotics. EAP actuators and sensors could improve the simplicity, compliance, physical scaling, and offer bio-inspired advantages in robotic locomotion, grasping and manipulation, and social expressions. For EAP actuators to realize their transformative potential, further innovations are needed: the actuators must be robust, fast, powerful, manufacturable, and affordable. This presentation surveys progress, opportunities, and challenges in the author's latest work in social robots and EAP actuators, and proposes a roadmap for EAP actuators in bio-inspired intelligent robotics.

  11. Spontaneous water filtration of bio-inspired membrane

    Science.gov (United States)

    Kim, Kiwoong; Kim, Hyejeong; Lee, Sang Joon

    2016-11-01

    Water is one of the most important elements for plants, because it is essential for various metabolic activities. Thus, water management systems of vascular plants, such as water collection and water filtration have been optimized through a long history. In this view point, bio-inspired technologies can be developed by mimicking the nature's strategies for the survival of the fittest. However, most of the underlying biophysical features of the optimized water management systems remain unsolved In this study, the biophysical characteristics of water filtration phenomena in the roots of mangrove are experimentally investigated. To understand water-filtration features of the mangrove, the morphological structures of its roots are analyzed. The electrokinetic properties of the root surface are also examined. Based on the quantitatively analyzed information, filtration of sodium ions in the roots are visualized. Motivated by this mechanism, spontaneous desalination mechanism in the root of mangrove is proposed by combining the electrokinetics and hydrodynamic transportation of ions. This study would be helpful for understanding the water-filtration mechanism of the roots of mangrove and developing a new bio-inspired desalination technology. This research was financially supported by the National Research Foundation (NRF) of Korea (Contract Grant Number: 2008-0061991).

  12. Distributed Synchronization Technique for OFDMA-Based Wireless Mesh Networks Using a Bio-Inspired Algorithm

    Directory of Open Access Journals (Sweden)

    Mi Jeong Kim

    2015-07-01

    Full Text Available In this paper, a distributed synchronization technique based on a bio-inspired algorithm is proposed for an orthogonal frequency division multiple access (OFDMA-based wireless mesh network (WMN with a time difference of arrival. The proposed time- and frequency-synchronization technique uses only the signals received from the neighbor nodes, by considering the effect of the propagation delay between the nodes. It achieves a fast synchronization with a relatively low computational complexity because it is operated in a distributed manner, not requiring any feedback channel for the compensation of the propagation delays. In addition, a self-organization scheme that can be effectively used to construct 1-hop neighbor nodes is proposed for an OFDMA-based WMN with a large number of nodes. The performance of the proposed technique is evaluated with regard to the convergence property and synchronization success probability using a computer simulation.

  13. Distributed Synchronization Technique for OFDMA-Based Wireless Mesh Networks Using a Bio-Inspired Algorithm.

    Science.gov (United States)

    Kim, Mi Jeong; Maeng, Sung Joon; Cho, Yong Soo

    2015-07-28

    In this paper, a distributed synchronization technique based on a bio-inspired algorithm is proposed for an orthogonal frequency division multiple access (OFDMA)-based wireless mesh network (WMN) with a time difference of arrival. The proposed time- and frequency-synchronization technique uses only the signals received from the neighbor nodes, by considering the effect of the propagation delay between the nodes. It achieves a fast synchronization with a relatively low computational complexity because it is operated in a distributed manner, not requiring any feedback channel for the compensation of the propagation delays. In addition, a self-organization scheme that can be effectively used to construct 1-hop neighbor nodes is proposed for an OFDMA-based WMN with a large number of nodes. The performance of the proposed technique is evaluated with regard to the convergence property and synchronization success probability using a computer simulation.

  14. Introducing Students to Bio-Inspiration and Biomimetic Design: A Workshop Experience

    Science.gov (United States)

    Santulli, Carlo; Langella, Carla

    2011-01-01

    In recent years, bio-inspired approach to design has gained considerable interest between designers, engineers and end-users. However, there are difficulties in introducing bio-inspiration concepts in the university curriculum in that they involve multi-disciplinary work, which can only possibly be successfully delivered by a team with integrated…

  15. Optimal Design of a Bio-Inspired Anthropocentric Shoulder Rehabilitator

    Directory of Open Access Journals (Sweden)

    S. K. Mustafa

    2006-01-01

    Full Text Available This paper presents the design of a bio-inspired anthropocentric 7-DOF wearable robotic arm for the purpose of stroke rehabilitation. The proposed arm rehabilitator synergistically utilizes the human arm structure with non-invasive kinematically under-deterministic cable-driven mechanisms to form a completely deterministic structure. It offers the advantages of being lightweight and having high dexterity. Adopting an anthropocentric design concept also allows it to conform to the human anatomical structure. The focus of this paper is on the analysis and design of the 3-DOF-shoulder module, called the shoulder rehabilitator. The design methodology is divided into three main steps: (1 performance evaluation of the cable-driven shoulder rehabilitator, (2 performance requirements of the shoulder joint based on its physiological characteristics and (3 design optimization of the shoulder rehabilitator based on shoulder joint physiological limitations. The aim is to determine a suitable configuration for the development of a shoulder rehabilitator prototype.

  16. Bio-Inspired Asynchronous Pixel Event Tricolor Vision Sensor.

    Science.gov (United States)

    Lenero-Bardallo, Juan Antonio; Bryn, D H; Hafliger, Philipp

    2014-06-01

    This article investigates the potential of the first ever prototype of a vision sensor that combines tricolor stacked photo diodes with the bio-inspired asynchronous pixel event communication protocol known as Address Event Representation (AER). The stacked photo diodes are implemented in a 22 × 22 pixel array in a standard STM 90 nm CMOS process. Dynamic range is larger than 60 dB and pixels fill factor is 28%. The pixels employ either simple pulse frequency modulation (PFM) or a Time-to-First-Spike (TFS) mode. A heuristic linear combination of the chip's inherent pseudo colors serves to approximate RGB color representation. Furthermore, the sensor outputs can be processed to represent the radiation in the near infrared (NIR) band without employing external filters, and to color-encode direction of motion due to an asymmetry in the update rates of the different diode layers.

  17. Wireless synapses in bio-inspired neural networks

    Science.gov (United States)

    Jannson, Tomasz; Forrester, Thomas; Degrood, Kevin

    2009-05-01

    Wireless (virtual) synapses represent a novel approach to bio-inspired neural networks that follow the infrastructure of the biological brain, except that biological (physical) synapses are replaced by virtual ones based on cellular telephony modeling. Such synapses are of two types: intracluster synapses are based on IR wireless ones, while intercluster synapses are based on RF wireless ones. Such synapses have three unique features, atypical of conventional artificial ones: very high parallelism (close to that of the human brain), very high reconfigurability (easy to kill and to create), and very high plasticity (easy to modify or upgrade). In this paper we analyze the general concept of wireless synapses with special emphasis on RF wireless synapses. Also, biological mammalian (vertebrate) neural models are discussed for comparison, and a novel neural lensing effect is discussed in detail.

  18. Copper removal using bio-inspired polydopamine coated natural zeolites

    International Nuclear Information System (INIS)

    Yu, Yang; Shapter, Joseph G.; Popelka-Filcoff, Rachel; Bennett, John W.; Ellis, Amanda V.

    2014-01-01

    Highlights: • Natural zeolites were modified with bio-inspired polydopamine. • A 91.4% increase in Cu(II) ion adsorption capacity was observed. • Atomic absorption and neutron activation analysis gave corroborative results. • Neutron activation analysis was used to provide accurate information on 30+ elements. • Approximately 90% of the adsorbed copper could be recovered by 0.1 M HCl treatment. - Abstract: Herein, for the first time, natural clinoptilolite-rich zeolite powders modified with a bio-inspired adhesive, polydopamine (PDA), have been systematically studied as an adsorbent for copper cations (Cu(II)) from aqueous solution. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) revealed successful grafting of PDA onto the zeolite surface. The effects of pH (2–5.5), PDA treatment time (3–24 h), contact time (0 to 24 h) and initial Cu(II) ion concentrations (1 to 500 mg dm −3 ) on the adsorption of Cu(II) ions were studied using atomic absorption spectroscopy (AAS) and neutron activation analysis (NAA). The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. The maximum adsorption capacities of Cu(II) were shown to be 14.93 mg g −1 for pristine natural zeolite and 28.58 mg g −1 for PDA treated zeolite powders. This impressive 91.4% increase in Cu(II) ion adsorption capacity is attributed to the chelating ability of the PDA on the zeolite surface. Furthermore studies of recyclability using NAA showed that over 50% of the adsorbed copper could be removed in mild concentrations (0.01 M or 0.1 M) of either acid or base

  19. Copper removal using bio-inspired polydopamine coated natural zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang; Shapter, Joseph G. [Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide 5042, SA (Australia); Popelka-Filcoff, Rachel [School of Chemical and Physical Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide 5042, SA (Australia); Bennett, John W. [Centre for Nuclear Applications, Australian Nuclear Science and Technology Organisation, Lucas Heights 2234, NSW (Australia); Ellis, Amanda V., E-mail: Amanda.Ellis@flinders.edu.au [Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide 5042, SA (Australia)

    2014-05-01

    Highlights: • Natural zeolites were modified with bio-inspired polydopamine. • A 91.4% increase in Cu(II) ion adsorption capacity was observed. • Atomic absorption and neutron activation analysis gave corroborative results. • Neutron activation analysis was used to provide accurate information on 30+ elements. • Approximately 90% of the adsorbed copper could be recovered by 0.1 M HCl treatment. - Abstract: Herein, for the first time, natural clinoptilolite-rich zeolite powders modified with a bio-inspired adhesive, polydopamine (PDA), have been systematically studied as an adsorbent for copper cations (Cu(II)) from aqueous solution. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) revealed successful grafting of PDA onto the zeolite surface. The effects of pH (2–5.5), PDA treatment time (3–24 h), contact time (0 to 24 h) and initial Cu(II) ion concentrations (1 to 500 mg dm{sup −3}) on the adsorption of Cu(II) ions were studied using atomic absorption spectroscopy (AAS) and neutron activation analysis (NAA). The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. The maximum adsorption capacities of Cu(II) were shown to be 14.93 mg g{sup −1} for pristine natural zeolite and 28.58 mg g{sup −1} for PDA treated zeolite powders. This impressive 91.4% increase in Cu(II) ion adsorption capacity is attributed to the chelating ability of the PDA on the zeolite surface. Furthermore studies of recyclability using NAA showed that over 50% of the adsorbed copper could be removed in mild concentrations (0.01 M or 0.1 M) of either acid or base.

  20. Bio-inspired approach for intelligent unattended ground sensors

    Science.gov (United States)

    Hueber, Nicolas; Raymond, Pierre; Hennequin, Christophe; Pichler, Alexander; Perrot, Maxime; Voisin, Philippe; Moeglin, Jean-Pierre

    2015-05-01

    Improving the surveillance capacity over wide zones requires a set of smart battery-powered Unattended Ground Sensors capable of issuing an alarm to a decision-making center. Only high-level information has to be sent when a relevant suspicious situation occurs. In this paper we propose an innovative bio-inspired approach that mimics the human bi-modal vision mechanism and the parallel processing ability of the human brain. The designed prototype exploits two levels of analysis: a low-level panoramic motion analysis, the peripheral vision, and a high-level event-focused analysis, the foveal vision. By tracking moving objects and fusing multiple criteria (size, speed, trajectory, etc.), the peripheral vision module acts as a fast relevant event detector. The foveal vision module focuses on the detected events to extract more detailed features (texture, color, shape, etc.) in order to improve the recognition efficiency. The implemented recognition core is able to acquire human knowledge and to classify in real-time a huge amount of heterogeneous data thanks to its natively parallel hardware structure. This UGS prototype validates our system approach under laboratory tests. The peripheral analysis module demonstrates a low false alarm rate whereas the foveal vision correctly focuses on the detected events. A parallel FPGA implementation of the recognition core succeeds in fulfilling the embedded application requirements. These results are paving the way of future reconfigurable virtual field agents. By locally processing the data and sending only high-level information, their energy requirements and electromagnetic signature are optimized. Moreover, the embedded Artificial Intelligence core enables these bio-inspired systems to recognize and learn new significant events. By duplicating human expertise in potentially hazardous places, our miniature visual event detector will allow early warning and contribute to better human decision making.

  1. Multi-Locomotion Robotic Systems New Concepts of Bio-inspired Robotics

    CERN Document Server

    Fukuda, Toshio; Sekiyama, Kosuke; Aoyama, Tadayoshi

    2012-01-01

    Nowadays, multiple attention have been paid on a robot working in the human living environment, such as in the field of medical, welfare, entertainment and so on. Various types of researches are being conducted actively in a variety of fields such as artificial intelligence, cognitive engineering, sensor- technology, interfaces and motion control. In the future, it is expected to realize super high functional human-like robot by integrating technologies in various fields including these types of researches. The book represents new developments and advances in the field of bio-inspired robotics research introducing the state of the art, the idea of multi-locomotion robotic system to implement the diversity of animal motion. It covers theoretical and computational aspects of Passive Dynamic Autonomous Control (PDAC), robot motion control, multi legged walking and climbing as well as brachiation focusing concrete robot systems, components and applications. In addition, gorilla type robot systems are described as...

  2. Formation Control for Water-Jet USV Based on Bio-Inspired Method

    Science.gov (United States)

    Fu, Ming-yu; Wang, Duan-song; Wang, Cheng-long

    2018-03-01

    The formation control problem for underactuated unmanned surface vehicles (USVs) is addressed by a distributed strategy based on virtual leader strategy. The control system takes account of disturbance induced by external environment. With the coordinate transformation, the advantage of the proposed scheme is that the control point can be any point of the ship instead of the center of gravity. By introducing bio-inspired model, the formation control problem is addressed with backstepping method. This avoids complicated computation, simplifies the control law, and smoothes the input signals. The system uniform ultimate boundness is proven by Lyapunov stability theory with Young inequality. Simulation results are presented to verify the effectiveness and robust of the proposed controller.

  3. Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio-Inspired Optimization Techniques

    Science.gov (United States)

    2017-11-01

    on Bio -Inspired Optimization Techniques by Canh Ly, Nghia Tran, and Ozlem Kilic Approved for public release; distribution is...Research Laboratory Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio -Inspired Optimization Techniques by...SUBTITLE Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio -Inspired Optimization Techniques 5a. CONTRACT NUMBER

  4. Bio-inspired routes for synthesizing efficient nanoscale platinum electrocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jennifer N. [Univ. of California, San Diego, CA (United States); Wang, Joseph [Univ. of California, San Diego, CA (United States)

    2014-08-31

    The overall objective of the proposed research is to use fundamental advances in bionanotechnology to design powerful platinum nanocrystal electrocatalysts for fuel cell applications. The new economically-viable, environmentally-friendly, bottom-up biochemical synthetic strategy will produce platinum nanocrystals with tailored size, shape and crystal orientation, hence leading to a maximum electrochemical reactivity. There are five specific aims to the proposed bio-inspired strategy for synthesizing efficient electrocatalytic platinum nanocrystals: (1) isolate peptides that both selectively bind particular crystal faces of platinum and promote the nucleation and growth of particular nanocrystal morphologies, (2) pattern nanoscale 2-dimensional arrays of platinum nucleating peptides from DNA scaffolds, (3) investigate the combined use of substrate patterned peptides and soluble peptides on nanocrystal morphology and growth (4) synthesize platinum crystals on planar and large-area carbon electrode supports, and (5) perform detailed characterization of the electrocatalytic behavior as a function of catalyst size, shape and morphology. Project Description and Impact: This bio-inspired collaborative research effort will address key challenges in designing powerful electrocatalysts for fuel cell applications by employing nucleic acid scaffolds in combination with peptides to perform specific, environmentally-friendly, simultaneous bottom-up biochemical synthesis and patterned assembly of highly uniform and efficient platinum nanocrystal catalysts. Bulk synthesis of nanoparticles usually produces a range of sizes, accessible catalytic sites, crystal morphologies, and orientations, all of which lead to inconsistent catalytic activities. In contrast, biological systems routinely demonstrate exquisite control over inorganic syntheses at neutral pH and ambient temperature and pressures. Because the orientation and arrangement of the templating biomolecules can be precisely

  5. Biomimetic and bio-inspired uses of mollusc shells.

    Science.gov (United States)

    Morris, J P; Wang, Y; Backeljau, T; Chapelle, G

    2016-06-01

    Climate change and ocean acidification are likely to have a profound effect on marine molluscs, which are of great ecological and economic importance. One process particularly sensitive to climate change is the formation of biominerals in mollusc shells. Fundamental research is broadening our understanding of the biomineralization process, as well as providing more informed predictions on the effects of climate change on marine molluscs. Such studies are important in their own right, but their value also extends to applied sciences. Biominerals, organic/inorganic hybrid materials with many remarkable physical and chemical properties, have been studied for decades, and the possibilities for future improved use of such materials for society are widely recognised. This article highlights the potential use of our understanding of the shell biomineralization process in novel bio-inspired and biomimetic applications. It also highlights the potential for the valorisation of shells produced as a by-product of the aquaculture industry. Studying shells and the formation of biominerals will inspire novel functional hybrid materials. It may also provide sustainable, ecologically- and economically-viable solutions to some of the problems created by current human resource exploitation. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Bio-inspired materials engineering using polysaccharide based biotemplates

    International Nuclear Information System (INIS)

    Zollfrank, C.

    2007-01-01

    Nano-structured materials with a controlled microstructure and tailored properties at a scale below 100 nm are of interest for applications in micro-mechanical, sensor and biomedical devices. In contrast to top-down manufacturing processes the formation of solid matter structures in nature is templated and directed by biomacromolecules such as polysaccharides and polypeptides. A promising biomimetic route for the directed deposition of ceramic materials is the application of anisotropically structured biomacromolecules as patterned templates. The polysaccharides exhibit a hierarchical multi scale order as well as self-assembly properties. The bio-inspired deposition and formation of ceramic phases on biomolecular polysaccharide templates was investigated. The polysaccharides were used at various structural levels from the molecular scale up to three-dimensional parts in the millimetre range. The versatility of polysaccharide shaping capabilities was explored using dissolved polysaccharide molecules as well as thin films for the or simultaneous or successive formation of inorganic mineral phases. Microalgae with a spherical appearance of 5 micro-m were applied in mineralisation studies. The extracellular polysaccharide (EPS) layers on the microalgae were used as biotemplates for manufacturing of functional ceramics. The obtained results on the mineralisation of inorganic phases on polysaccharides are adapted for novel biomimetic routes used in the fabrication for functional and biomedical ceramics. (author)

  7. Engineered bio-inspired coating for reduction of flow separation

    Science.gov (United States)

    Bocanegra Evans, Humberto; Hamed, Ali M.; Gorumlu, Serdar; Doosttalab, Ali; Aksak, Burak; Chamorro, Leonardo P.; Castillo, Luciano

    2017-11-01

    Flow control using passive strategies has received notable attention in the last decades as a way to increase mixing and reduce skin drag, among others. Here, we present a bio-inspired coating, composed by uniformly distributed pillars with diverging tips, that is able to reduce the recirculation region in highly separated flows. This is demonstrated with laboratory experiments in a refractive index-matching flume at Reynolds number Reθ 1200 . The flow over an expanding channel following a S835 wing section was characterized with the coating and with smooth walls. High-resolution, wall-normal particle image velocimetry show a significant reduction of the reversed flow with the coating, where the region with reverse flow was reduced by 60 % . The performance of the micro-scale coating is surprising since the size of the fibers are nearly coincident with the viscous length scale (k+ 1). Additionally, the flow control properties of the surface do not depend on hydrophobicity, giving the coating the capability to work in both air and water media.

  8. A bio-inspired memory model for structural health monitoring

    Science.gov (United States)

    Zheng, Wei; Zhu, Yong

    2009-04-01

    Long-term structural health monitoring (SHM) systems need intelligent management of the monitoring data. By analogy with the way the human brain processes memories, we present a bio-inspired memory model (BIMM) that does not require prior knowledge of the structure parameters. The model contains three time-domain areas: a sensory memory area, a short-term memory area and a long-term memory area. First, the initial parameters of the structural state are specified to establish safety criteria. Then the large amount of monitoring data that falls within the safety limits is filtered while the data outside the safety limits are captured instantly in the sensory memory area. Second, disturbance signals are distinguished from danger signals in the short-term memory area. Finally, the stable data of the structural balance state are preserved in the long-term memory area. A strategy for priority scheduling via fuzzy c-means for the proposed model is then introduced. An experiment on bridge tower deformation demonstrates that the proposed model can be applied for real-time acquisition, limited-space storage and intelligent mining of the monitoring data in a long-term SHM system.

  9. A bio-inspired memory model for structural health monitoring

    International Nuclear Information System (INIS)

    Zheng, Wei; Zhu, Yong

    2009-01-01

    Long-term structural health monitoring (SHM) systems need intelligent management of the monitoring data. By analogy with the way the human brain processes memories, we present a bio-inspired memory model (BIMM) that does not require prior knowledge of the structure parameters. The model contains three time-domain areas: a sensory memory area, a short-term memory area and a long-term memory area. First, the initial parameters of the structural state are specified to establish safety criteria. Then the large amount of monitoring data that falls within the safety limits is filtered while the data outside the safety limits are captured instantly in the sensory memory area. Second, disturbance signals are distinguished from danger signals in the short-term memory area. Finally, the stable data of the structural balance state are preserved in the long-term memory area. A strategy for priority scheduling via fuzzy c-means for the proposed model is then introduced. An experiment on bridge tower deformation demonstrates that the proposed model can be applied for real-time acquisition, limited-space storage and intelligent mining of the monitoring data in a long-term SHM system

  10. A Bio-Inspired Herbal Tea Flavour Assessment Technique

    Directory of Open Access Journals (Sweden)

    Nur Zawatil Isqi Zakaria

    2014-07-01

    Full Text Available Herbal-based products are becoming a widespread production trend among manufacturers for the domestic and international markets. As the production increases to meet the market demand, it is very crucial for the manufacturer to ensure that their products have met specific criteria and fulfil the intended quality determined by the quality controller. One famous herbal-based product is herbal tea. This paper investigates bio-inspired flavour assessments in a data fusion framework involving an e-nose and e-tongue. The objectives are to attain good classification of different types and brands of herbal tea, classification of different flavour masking effects and finally classification of different concentrations of herbal tea. Two data fusion levels were employed in this research, low level data fusion and intermediate level data fusion. Four classification approaches; LDA, SVM, KNN and PNN were examined in search of the best classifier to achieve the research objectives. In order to evaluate the classifiers’ performance, an error estimator based on k-fold cross validation and leave-one-out were applied. Classification based on GC-MS TIC data was also included as a comparison to the classification performance using fusion approaches. Generally, KNN outperformed the other classification techniques for the three flavour assessments in the low level data fusion and intermediate level data fusion. However, the classification results based on GC-MS TIC data are varied.

  11. A tracked robot with novel bio-inspired passive "legs".

    Science.gov (United States)

    Sun, Bo; Jing, Xingjian

    2017-01-01

    For track-based robots, an important aspect is the suppression design, which determines the trafficability and comfort of the whole system. The trafficability limits the robot's working capability, and the riding comfort limits the robot's working effectiveness, especially with some sensitive instruments mounted on or operated. To these aims, a track-based robot equipped with a novel passive bio-inspired suspension is designed and studied systematically in this paper. Animal or insects have very special leg or limb structures which are good for motion control and adaptable to different environments. Inspired by this, a new track-based robot is designed with novel "legs" for connecting the loading wheels to the robot body. Each leg is designed with passive structures and can achieve very high loading capacity but low dynamic stiffness such that the robot can move on rough ground similar to a multi-leg animal or insect. Therefore, the trafficability and riding comfort can be significantly improved without losing loading capacity. The new track-based robot can be well applied to various engineering tasks for providing a stable moving platform of high mobility, better trafficability and excellent loading capacity.

  12. A bio-inspired electrocommunication system for small underwater robots.

    Science.gov (United States)

    Wang, Wei; Liu, Jindong; Xie, Guangming; Wen, Li; Zhang, Jianwei

    2017-03-29

    Weakly electric fishes (Gymnotid and Mormyrid) use an electric field to communicate efficiently (termed electrocommunication) in the turbid waters of confined spaces where other communication modalities fail. Inspired by this biological phenomenon, we design an artificial electrocommunication system for small underwater robots and explore the capabilities of such an underwater robotic communication system. An analytical model for electrocommunication is derived to predict the effect of the key parameters such as electrode distance and emitter current of the system on the communication performance. According to this model, a low-dissipation, and small-sized electrocommunication system is proposed and integrated into a small robotic fish. We characterize the communication performance of the robot in still water, flowing water, water with obstacles and natural water conditions. The results show that underwater robots are able to communicate electrically at a speed of around 1 k baud within about 3 m with a low power consumption (less than 1 W). In addition, we demonstrate that two leader-follower robots successfully achieve motion synchronization through electrocommunication in the three-dimensional underwater space, indicating that this bio-inspired electrocommunication system is a promising setup for the interaction of small underwater robots.

  13. SABRE: a bio-inspired fault-tolerant electronic architecture

    International Nuclear Information System (INIS)

    Bremner, P; Samie, M; Dragffy, G; Pipe, A G; Liu, Y; Tempesti, G; Timmis, J; Tyrrell, A M

    2013-01-01

    As electronic devices become increasingly complex, ensuring their reliable, fault-free operation is becoming correspondingly more challenging. It can be observed that, in spite of their complexity, biological systems are highly reliable and fault tolerant. Hence, we are motivated to take inspiration for biological systems in the design of electronic ones. In SABRE (self-healing cellular architectures for biologically inspired highly reliable electronic systems), we have designed a bio-inspired fault-tolerant hierarchical architecture for this purpose. As in biology, the foundation for the whole system is cellular in nature, with each cell able to detect faults in its operation and trigger intra-cellular or extra-cellular repair as required. At the next level in the hierarchy, arrays of cells are configured and controlled as function units in a transport triggered architecture (TTA), which is able to perform partial-dynamic reconfiguration to rectify problems that cannot be solved at the cellular level. Each TTA is, in turn, part of a larger multi-processor system which employs coarser grain reconfiguration to tolerate faults that cause a processor to fail. In this paper, we describe the details of operation of each layer of the SABRE hierarchy, and how these layers interact to provide a high systemic level of fault tolerance. (paper)

  14. Robust, Self-Contained and Bio-Inspired Shear Sensor Array, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a robust, bio-inspired, and self-contained sensor array for the measurement of shear stress. The proposed system uses commercially...

  15. Compressive Sensing Based Bio-Inspired Shape Feature Detection CMOS Imager

    Science.gov (United States)

    Duong, Tuan A. (Inventor)

    2015-01-01

    A CMOS imager integrated circuit using compressive sensing and bio-inspired detection is presented which integrates novel functions and algorithms within a novel hardware architecture enabling efficient on-chip implementation.

  16. Bio-Inspired Autonomous Communications Systems with Anomaly Detection Monitoring, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and demonstrate BioComm, a bio-inspired autonomous communications system (ACS) aimed at dynamically reconfiguring and redeploying autonomous...

  17. Bio-Inspired Design Approach Analysis: A Case Study of Antoni Gaudi and Santiago Calatrava

    OpenAIRE

    Marzieh Imani

    2017-01-01

    Antoni Gaudi and Santiago Calatrava have reputation for designing bio-inspired creative and technical buildings. Even though they have followed different independent approaches towards design, the source of bio-inspiration seems to be common. Taking a closer look at their projects reveals that Calatrava has been influenced by Gaudi in terms of interpreting nature and applying natural principles into the design process. This research firstly discusses the dialogue between Biomimicry and archit...

  18. Bio-inspired aquatic robotics by untethered piezohydroelastic actuation

    International Nuclear Information System (INIS)

    Cen, L; Erturk, A

    2013-01-01

    This paper investigates fish-like aquatic robotics using flexible bimorphs made of macro-fiber composite (MFC) piezoelectric laminates for carangiform locomotion. In addition to noiseless and efficient actuation over a range of frequencies, geometric scalability, and simple design, bimorph propulsors made of MFCs offer a balance between the actuation force and velocity response for performance enhancement in bio-inspired swimming. The experimental component of the presented work focuses on the characterization of an elastically constrained MFC bimorph propulsor for thrust generation in quiescent water as well as the development of a robotic fish prototype combining a microcontroller and a printed-circuit-board amplifier to generate high actuation voltage for untethered locomotion. From the theoretical standpoint, a distributed-parameter electroelastic model including the hydrodynamic effects and actuator dynamics is coupled with the elongated-body theory for predicting the mean thrust in quiescent water. In-air and underwater experiments are performed to verify the incorporation of hydrodynamic effects in the linear actuation regime. For electroelastically nonlinear actuation levels, experimentally obtained underwater vibration response is coupled with the elongated-body theory to predict the thrust output. The measured mean thrust levels in quiescent water (on the order of ∼10 mN) compare favorably with thrust levels of biological fish. An untethered robotic fish prototype that employs a single bimorph fin (caudal fin) for straight swimming and turning motions is developed and tested in free locomotion. A swimming speed of 0.3 body-length/second (7.5 cm s −1 swimming speed for 24.3 cm body length) is achieved at 5 Hz for a non-optimized main body-propulsor bimorph combination under a moderate actuation voltage level. (paper)

  19. Viscous-Inviscid Methods in Unsteady Aerodynamic Analysis of Bio-Inspired Morphing Wings

    Science.gov (United States)

    Dhruv, Akash V.

    Flight has been one of the greatest realizations of human imagination, revolutionizing communication and transportation over the years. This has greatly influenced the growth of technology itself, enabling researchers to communicate and share their ideas more effectively, extending the human potential to create more sophisticated systems. While the end product of a sophisticated technology makes our lives easier, its development process presents an array of challenges in itself. In last decade, scientists and engineers have turned towards bio-inspiration to design more efficient and robust aerodynamic systems to enhance the ability of Unmanned Aerial Vehicles (UAVs) to be operated in cluttered environments, where tight maneuverability and controllability are necessary. Effective use of UAVs in domestic airspace will mark the beginning of a new age in communication and transportation. The design of such complex systems necessitates the need for faster and more effective tools to perform preliminary investigations in design, thereby streamlining the design process. This thesis explores the implementation of numerical panel methods for aerodynamic analysis of bio-inspired morphing wings. Numerical panel methods have been one of the earliest forms of computational methods for aerodynamic analysis to be developed. Although the early editions of this method performed only inviscid analysis, the algorithm has matured over the years as a result of contributions made by prominent aerodynamicists. The method discussed in this thesis is influenced by recent advancements in panel methods and incorporates both viscous and inviscid analysis of multi-flap wings. The surface calculation of aerodynamic coefficients makes this method less computationally expensive than traditional Computational Fluid Dynamics (CFD) solvers available, and thus is effective when both speed and accuracy are desired. The morphing wing design, which consists of sequential feather-like flaps installed

  20. Biomimicry as an approach for bio-inspired structure with the aid of compu

    Directory of Open Access Journals (Sweden)

    Moheb Sabry Aziz

    2016-03-01

    Full Text Available Biomimicry is the study of emulating and mimicking nature, where it has been used by designers to help in solving human problems. From centuries ago designers and architects looked at nature as a huge source of inspiration. Biomimicry argues that nature is the best, most influencing and the guaranteed source of innovation for the designers as a result of nature’s 3.85 billion years of evolution, as it holds a gigantic experience of solving problems of the environment and its inhabitants. The biomimicry emerging field deals with new technologies honed from bio-inspired engineering at the micro and macro scale levels. Architects have been searching for answers from nature to their complex questions about different kinds of structures, and they have mimicked a lot of forms from nature to create better and more efficient structures for different architectural purposes. Without computers these complex ways and forms of structures couldn’t been mimicked and thus using computers had risen the way of mimicking and taking inspiration from nature because it is considered a very sophisticated and accurate tool for simulation and computing, as a result designers can imitate different nature’s models in spite of its complexity.

  1. Bio-Inspired Vision-Based Leader-Follower Formation Flying in the Presence of Delays

    Directory of Open Access Journals (Sweden)

    John Oyekan

    2016-08-01

    Full Text Available Flocking starlings at dusk are known for the mesmerizing and intricate shapes they generate, as well as how fluid these shapes change. They seem to do this effortlessly. Real-life vision-based flocking has not been achieved in micro-UAVs (micro Unmanned Aerial Vehicles to date. Towards this goal, we make three contributions in this paper: (i we used a computational approach to develop a bio-inspired architecture for vision-based Leader-Follower formation flying on two micro-UAVs. We believe that the minimal computational cost of the resulting algorithm makes it suitable for object detection and tracking during high-speed flocking; (ii we show that provided delays in the control loop of a micro-UAV are below a critical value, Kalman filter-based estimation algorithms are not required to achieve Leader-Follower formation flying; (iii unlike previous approaches, we do not use external observers, such as GPS signals or synchronized communication with flock members. These three contributions could be useful in achieving vision-based flocking in GPS-denied environments on computationally-limited agents.

  2. A Review of Natural Joint Systems and Numerical Investigation of Bio-Inspired GFRP-to-Steel Joints

    Directory of Open Access Journals (Sweden)

    Evangelos I. Avgoulas

    2016-07-01

    Full Text Available There are a great variety of joint types used in nature which can inspire engineering joints. In order to design such biomimetic joints, it is at first important to understand how biological joints work. A comprehensive literature review, considering natural joints from a mechanical point of view, was undertaken. This was used to develop a taxonomy based on the different methods/functions that nature successfully uses to attach dissimilar tissues. One of the key methods that nature uses to join dissimilar materials is a transitional zone of stiffness at the insertion site. This method was used to propose bio-inspired solutions with a transitional zone of stiffness at the joint site for several glass fibre reinforced plastic (GFRP to steel adhesively bonded joint configurations. The transition zone was used to reduce the material stiffness mismatch of the joint parts. A numerical finite element model was used to identify the optimum variation in material stiffness that minimises potential failure of the joint. The best bio-inspired joints showed a 118% increase of joint strength compared to the standard joints.

  3. Operant Conditioning: A Minimal Components Requirement in Artificial Spiking Neurons Designed for Bio-Inspired Robot’s Controller

    Directory of Open Access Journals (Sweden)

    André eCyr

    2014-07-01

    Full Text Available We demonstrate the operant conditioning (OC learning process within a basic bio-inspired robot controller paradigm, using an artificial spiking neural network (ASNN with minimal component count as artificial brain. In biological agents, OC results in behavioral changes that are learned from the consequences of previous actions, using progressive prediction adjustment triggered by reinforcers. In a robotics context, virtual and physical robots may benefit from a similar learning skill when facing unknown environments with no supervision. In this work, we demonstrate that a simple ASNN can efficiently realise many OC scenarios. The elementary learning kernel that we describe relies on a few critical neurons, synaptic links and the integration of habituation and spike-timing dependent plasticity (STDP as learning rules. Using four tasks of incremental complexity, our experimental results show that such minimal neural component set may be sufficient to implement many OC procedures. Hence, with the described bio-inspired module, OC can be implemented in a wide range of robot controllers, including those with limited computational resources.

  4. Bio-inspired Edible Superhydrophobic Interface for Reducing Residual Liquid Food.

    Science.gov (United States)

    Li, Yao; Bi, Jingran; Wang, Siqi; Zhang, Tan; Xu, Xiaomeng; Wang, Haitao; Cheng, Shasha; Zhu, Bei-Wei; Tan, Mingqian

    2018-03-07

    Significant wastage of residual liquid food, such as milk, yogurt, and honey, in food containers has attracted great attention. In this work, a bio-inspired edible superhydrophobic interface was fabricated using U.S. Food and Drug Administration-approved and edible honeycomb wax, arabic gum, and gelatin by a simple and low-cost method. The bio-inspired edible superhydrophobic interface showed multiscale structures, which were similar to that of a lotus leaf surface. This bio-inspired edible superhydrophobic interface displayed high contact angles for a variety of liquid foods, and the residue of liquid foods could be effectively reduced using the bio-inspired interface. To improve the adhesive force of the superhydrophobic interface, a flexible edible elastic film was fabricated between the interface and substrate material. After repeated folding and flushing for a long time, the interface still maintained excellent superhydrophobic property. The bio-inspired edible superhydrophobic interface showed good biocompatibility, which may have potential applications as a functional packaging interface material.

  5. Bio-inspired passive actuator simulating an abalone shell mechanism for structural control

    International Nuclear Information System (INIS)

    Yang, Henry T Y; Lin, Chun-Hung; Bridges, Daniel; Randall, Connor J; Hansma, Paul K

    2010-01-01

    An energy dispersion mechanism called 'sacrificial bonds and hidden length', which is found in some biological systems, such as abalone shells and bones, is the inspiration for new strategies for structural control. Sacrificial bonds and hidden length can substantially increase the stiffness and enhance energy dissipation in the constituent molecules of abalone shells and bone. Having been inspired by the usefulness and effectiveness of such a mechanism, which has evolved over millions of years and countless cycles of evolutions, the authors employ the conceptual underpinnings of this mechanism to develop a bio-inspired passive actuator. This paper presents a fundamental method for optimally designing such bio-inspired passive actuators for structural control. To optimize the bio-inspired passive actuator, a simple method utilizing the force–displacement–velocity (FDV) plots based on LQR control is proposed. A linear regression approach is adopted in this research to find the initial values of the desired parameters for the bio-inspired passive actuator. The illustrative examples, conducted by numerical simulation with experimental validation, suggest that the bio-inspired passive actuator based on sacrificial bonds and hidden length may be comparable in performance to state-of-the-art semi-active actuators

  6. Bio-inspired passive actuator simulating an abalone shell mechanism for structural control

    Science.gov (United States)

    Yang, Henry T. Y.; Lin, Chun-Hung; Bridges, Daniel; Randall, Connor J.; Hansma, Paul K.

    2010-10-01

    An energy dispersion mechanism called 'sacrificial bonds and hidden length', which is found in some biological systems, such as abalone shells and bones, is the inspiration for new strategies for structural control. Sacrificial bonds and hidden length can substantially increase the stiffness and enhance energy dissipation in the constituent molecules of abalone shells and bone. Having been inspired by the usefulness and effectiveness of such a mechanism, which has evolved over millions of years and countless cycles of evolutions, the authors employ the conceptual underpinnings of this mechanism to develop a bio-inspired passive actuator. This paper presents a fundamental method for optimally designing such bio-inspired passive actuators for structural control. To optimize the bio-inspired passive actuator, a simple method utilizing the force-displacement-velocity (FDV) plots based on LQR control is proposed. A linear regression approach is adopted in this research to find the initial values of the desired parameters for the bio-inspired passive actuator. The illustrative examples, conducted by numerical simulation with experimental validation, suggest that the bio-inspired passive actuator based on sacrificial bonds and hidden length may be comparable in performance to state-of-the-art semi-active actuators.

  7. Design and Dynamics Analysis of a Bio-Inspired Intermittent Hopping Robot for Planetary Surface Exploration

    Directory of Open Access Journals (Sweden)

    Long Bai

    2012-10-01

    Full Text Available A small, bio-inspired and minimally actuated intermittent hopping robot for planetary surface exploration is proposed in this paper. The robot uses a combined-geared six-bar linkage/spring mechanism, which has a possible rich trajectory and metamorphic characteristics and, due to this, the robot is able to recharge, lock/release and jump by using just a micro-power motor as the actuator. Since the robotic system has a closed-chain structure and employs underactuated redundant motion, the constrained multi-body dynamics are derived with time-varying driving parameters and ground unilateral constraint both taken into consideration. In addition, the established dynamics equations, mixed of higher order differential and algebraic expressions, are solved by the immediate integration algorithm. A prototype is implemented and experiments are carried out. The results show that the robot, using a micro-power motor as the actuator and solar cells as the power supply, can achieve a biomimetic multi-body hopping stance and a nonlinearly increasing driving force. Typically, the robot can jump a horizontal distance of about 1 m and a vertical height of about 0.3 m, with its trunk and foot moving stably during takeoff. In addition, the computational and experimental results are consistent as regards the hopping performance of the robot, which suggests that the proposed dynamics model and its solution have general applicability to motion prediction and the performance analysis of intermittent hopping robots.

  8. Novel bio-inspired smart control for hazard mitigation of civil structures

    International Nuclear Information System (INIS)

    Kim, Yeesock; Kim, Changwon; Langari, Reza

    2010-01-01

    In this paper, a new bio-inspired controller is proposed for vibration mitigation of smart structures subjected to ground disturbances (i.e. earthquakes). The control system is developed through the integration of a brain emotional learning (BEL) algorithm with a proportional–integral–derivative (PID) controller and a semiactive inversion (Inv) algorithm. The BEL algorithm is based on the neurologically inspired computational model of the amygdala and the orbitofrontal cortex. To demonstrate the effectiveness of the proposed hybrid BEL–PID–Inv control algorithm, a seismically excited building structure equipped with a magnetorheological (MR) damper is investigated. The performance of the proposed hybrid BEL–PID–Inv control algorithm is compared with that of passive, PID, linear quadratic Gaussian (LQG), and BEL control systems. In the simulation, the robustness of the hybrid BEL–PID–Inv control algorithm in the presence of modeling uncertainties as well as external disturbances is investigated. It is shown that the proposed hybrid BEL–PID–Inv control algorithm is effective in improving the dynamic responses of seismically excited building structure–MR damper systems

  9. Medical Image Registration by means of a Bio-Inspired Optimization Strategy

    Directory of Open Access Journals (Sweden)

    Hariton Costin

    2012-07-01

    Full Text Available Medical imaging mainly treats and processes missing, ambiguous, complementary, redundant and distorted data. Biomedical image registration is the process of geometric overlaying or alignment of two or more 2D/3D images of the same scene, taken at different time slots, from different angles, and/or by different acquisition systems. In medical practice, it is becoming increasingly important in diagnosis, treatment planning, functional studies, computer-guided therapies, and in biomedical research. Technically, image registration implies a complex optimization of different parameters, performed at local or/and global levels. Local optimization methods frequently fail because functions of the involved metrics with respect to transformation parameters are generally nonconvex and irregular. Therefore, global methods are often required, at least at the beginning of the procedure. In this paper, a new evolutionary and bio-inspired approach -- bacterial foraging optimization -- is adapted for single-slice to 3-D PET and CT multimodal image registration. Preliminary results of optimizing the normalized mutual information similarity metric validated the efficacy of the proposed method by using a freely available medical image database.

  10. Erosion resistance of pipe bends with bio-inspired internal surfaces

    Science.gov (United States)

    Zhang, Chengchun; Matar, Omar

    2013-11-01

    Guided by the structure of a shell surface, a bio-inspired surface is proposed to enhance the erosion resistance of pipe bends carrying crude-oil and sand in the turbulent flow regime. A comparison of the erosion rate between a smooth bend and the bio-inspired one is carried out using numerical simulations: large eddy simulations are used to simulate turbulence, and these are coupled to a discrete element method for the solid particles. The results indicate that the bio-inspired surface can control effectively the liquid-solid flow near the wall, and decrease the particle-wall force. This, then, leads to a reduction in the erosion rate brought about by the sand transported by the crude-oil in the pipe bend. The China Scholarship Council is gratefully acknowledged.

  11. Development of a bio-inspired UAV perching system

    Science.gov (United States)

    Xie, Pu

    of animals and human arms approaching to a fixed or moving target for grasping or capturing. The autonomous flight control was also implemented through a PID controller. Autonomous flight performance was proved through simulation in SimMechanics. Finally, the prototyping of our designs were conducted in different generations of our bio-inspired UAV perching system, which include the leg prototype, gripper prototype, and system prototype. Both the machined prototype and 3D printed prototype were tried. The performance of these prototypes was tested through experiments.

  12. Bio-inspired polymeric patterns with enhanced wear durability for microsystem applications

    International Nuclear Information System (INIS)

    Singh, R. Arvind; Siyuan, L.; Satyanarayana, N.; Kustandi, T.S.; Sinha, Sujeet K.

    2011-01-01

    At micro/nano-scale, friction force dominates at the interface between bodies moving in relative motion and severely affects their smooth operation. This effect limits the performance of microsystem devices such as micro-electro-mechanical systems (MEMS). In addition, friction force also leads to material removal or wear and thereby reduces the durability i.e. the useful operating life of the devices. In this work, we fabricated bio-inspired polymeric patterns for tribological applications. Inspired by the surface features on lotus leaves namely, the protuberances and wax, SU-8 polymeric films spin-coated on silicon wafers were topographically and chemically modified. For topographical modification, micro-scale patterns were fabricated using nanoimprint lithography and for chemical modification, the micro-patterns were coated with perfluoropolyether nanolubricant. Tribological investigation of the bio-inspired patterns revealed that the friction coefficients reduced significantly and the wear durability increased by several orders. In order to enhance the wear durability much further, the micro-patterns were exposed to argon/oxygen plasma and were subsequently coated with the perfluoropolyether nanolubricant. Bio-inspired patterns with enhanced wear durability, such as the ones investigated in the current work, have potential tribological applications in MEMS/Bio-MEMS actuator-based devices. Highlights: →Bio-inspired polymeric patterns for tribological applications in microsystems. →Novel surface modification for the patterns to enhance tribological properties. →Patterns show low friction properties and extremely high wear durability.

  13. Interactive Learning Environment for Bio-Inspired Optimization Algorithms for UAV Path Planning

    Science.gov (United States)

    Duan, Haibin; Li, Pei; Shi, Yuhui; Zhang, Xiangyin; Sun, Changhao

    2015-01-01

    This paper describes the development of BOLE, a MATLAB-based interactive learning environment, that facilitates the process of learning bio-inspired optimization algorithms, and that is dedicated exclusively to unmanned aerial vehicle path planning. As a complement to conventional teaching methods, BOLE is designed to help students consolidate the…

  14. Bio-inspired fuel cells for miniaturized body-area-networks applications

    NARCIS (Netherlands)

    Xu, Wei; Gao, Lu; Danilov, Dmitri; Pop, V.; Notten, Peter

    2010-01-01

    The improvement in quality of modern health-care is closely related to the need for medical autonomous systems that enable people to ‘carry’ their personal wireless Body-Area-Network (BAN). Bio-inspired fuel cells (BFC) are a promising approach of energy harvesting to achieve autonomy and

  15. Crickets as bio-inspiration for MEMS-based flow-sensing

    NARCIS (Netherlands)

    Krijnen, Gijsbertus J.M.; Droogendijk, H.; Dagamseh, A.M.K.; Jaganatharaja, R.K.; Casas, Jerome

    2014-01-01

    MEMS offers exciting possibilities for the fabrication of bio-inspired mechanosensors. Over the last few years, we have been working on cricket- inspired hair-sensor arrays for spatio-temporal flow-field observations (i.e. flow camera) and source localisation. Whereas making flow-sensors as energy

  16. Bio-inspired grasp control in a robotic hand with massive sensorial input.

    Science.gov (United States)

    Ascari, Luca; Bertocchi, Ulisse; Corradi, Paolo; Laschi, Cecilia; Dario, Paolo

    2009-02-01

    The capability of grasping and lifting an object in a suitable, stable and controlled way is an outstanding feature for a robot, and thus far, one of the major problems to be solved in robotics. No robotic tools able to perform an advanced control of the grasp as, for instance, the human hand does, have been demonstrated to date. Due to its capital importance in science and in many applications, namely from biomedics to manufacturing, the issue has been matter of deep scientific investigations in both the field of neurophysiology and robotics. While the former is contributing with a profound understanding of the dynamics of real-time control of the slippage and grasp force in the human hand, the latter tries more and more to reproduce, or take inspiration by, the nature's approach, by means of hardware and software technology. On this regard, one of the major constraints robotics has to overcome is the real-time processing of a large amounts of data generated by the tactile sensors while grasping, which poses serious problems to the available computational power. In this paper a bio-inspired approach to tactile data processing has been followed in order to design and test a hardware-software robotic architecture that works on the parallel processing of a large amount of tactile sensing signals. The working principle of the architecture bases on the cellular nonlinear/neural network (CNN) paradigm, while using both hand shape and spatial-temporal features obtained from an array of microfabricated force sensors, in order to control the sensory-motor coordination of the robotic system. Prototypical grasping tasks were selected to measure the system performances applied to a computer-interfaced robotic hand. Successful grasps of several objects, completely unknown to the robot, e.g. soft and deformable objects like plastic bottles, soft balls, and Japanese tofu, have been demonstrated.

  17. Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle

    International Nuclear Information System (INIS)

    Nakata, T; Liu, H; Nishihashi, N; Wang, X; Sato, A; Tanaka, Y

    2011-01-01

    MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s −1 , operate in a Reynolds number regime of 10 5 or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4–3.0 g and a wingspan of 10–12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.

  18. A bio-inspired real-time capable artificial lateral line system for freestream flow measurements.

    Science.gov (United States)

    Abels, C; Qualtieri, A; De Vittorio, M; Megill, W M; Rizzi, F

    2016-06-03

    To enhance today's artificial flow sensing capabilities in aerial and underwater robotics, future robots could be equipped with a large number of miniaturized sensors distributed over the surface to provide high resolution measurement of the surrounding fluid flow. In this work we show a linear array of closely separated bio-inspired micro-electro-mechanical flow sensors whose sensing mechanism is based on a piezoresistive strain-gauge along a stress-driven cantilever beam, mimicking the biological superficial neuromasts found in the lateral line organ of fishes. Aiming to improve state-of-the-art flow sensing capability in autonomously flying and swimming robots, our artificial lateral line system was designed and developed to feature multi-parameter freestream flow measurements which provide information about (1) local flow velocities as measured by the signal amplitudes from the individual cantilevers as well as (2) propagation velocity, (3) linear forward/backward direction along the cantilever beam orientation and (4) periodicity of pulses or pulse trains determined by cross-correlating sensor signals. A real-time capable cross-correlation procedure was developed which makes it possible to extract freestream flow direction and velocity information from flow fluctuations. The computed flow velocities deviate from a commercial system by 0.09 m s(-1) at 0.5 m s(-1) and 0.15 m s(-1) at 1.0 m s(-1) flow velocity for a sampling rate of 240 Hz and a sensor distance of 38 mm. Although experiments were performed in air, the presented flow sensing system can be applied to underwater vehicles as well, once the sensors are embedded in a waterproof micro-electro-mechanical systems package.

  19. A bio-inspired asynchronous skin system for crack detection applications

    International Nuclear Information System (INIS)

    Sharp, Nathan; Kuntz, Alan; Brubaker, Cole; Amos, Stephanie; Gao, Wei; Gupta, Gautum; Mohite, Aditya; Farrar, Charles; Mascareñas, David

    2014-01-01

    In many applications of structural health monitoring (SHM) it is imperative or advantageous to have large sensor arrays in order to properly sense the state of health of the structure. Typically these sensor networks are implemented by placing a large number of sensors over a structure and running individual cables from each sensor back to a central measurement station. Data is then collected from each sensor on the network at a constant sampling rate regardless of the current timescales at which events are acting on the structure. These conventional SHM sensor networks have a number of shortfalls. They tend to have a large number of cables that can represent a single point of failure for each sensor as well as add significant weight and installation costs. The constant sampling rate associated with each sensor very quickly leads to large amounts of data that must be analyzed, stored, and possibly transmitted to a remote user. This leads to increased demands on power consumption, bandwidth, and size. It also taxes our current techniques for managing large amounts of data. For the last decade the goal of the SHM community has been to endow structures with the functionality of a biological nervous system. Despite this goal the community has predominantly ignored the biological nervous system as inspiration for building structural nervous systems, choosing instead to focus on experimental mechanics and simulation techniques. In this work we explore the use of a novel, bio-inspired, SHM skin. This skin makes use of distributed computing and asynchronous communication techniques to alleviate the scale of the data management challenge as well as reduce power. The system also periodically sends a ‘heat beat’ signal to provide state-of-health updates. This conductive skin was implemented using conductive ink resistors as well as with graphene-oxide capacitors. (paper)

  20. A two-dimensional iterative panel method and boundary layer model for bio-inspired multi-body wings

    Science.gov (United States)

    Blower, Christopher J.; Dhruv, Akash; Wickenheiser, Adam M.

    2014-03-01

    The increased use of Unmanned Aerial Vehicles (UAVs) has created a continuous demand for improved flight capabilities and range of use. During the last decade, engineers have turned to bio-inspiration for new and innovative flow control methods for gust alleviation, maneuverability, and stability improvement using morphing aircraft wings. The bio-inspired wing design considered in this study mimics the flow manipulation techniques performed by birds to extend the operating envelope of UAVs through the installation of an array of feather-like panels across the airfoil's upper and lower surfaces while replacing the trailing edge flap. Each flap has the ability to deflect into both the airfoil and the inbound airflow using hinge points with a single degree-of-freedom, situated at 20%, 40%, 60% and 80% of the chord. The installation of the surface flaps offers configurations that enable advantageous maneuvers while alleviating gust disturbances. Due to the number of possible permutations available for the flap configurations, an iterative constant-strength doublet/source panel method has been developed with an integrated boundary layer model to calculate the pressure distribution and viscous drag over the wing's surface. As a result, the lift, drag and moment coefficients for each airfoil configuration can be calculated. The flight coefficients of this numerical method are validated using experimental data from a low speed suction wind tunnel operating at a Reynolds Number 300,000. This method enables the aerodynamic assessment of a morphing wing profile to be performed accurately and efficiently in comparison to Computational Fluid Dynamics methods and experiments as discussed herein.

  1. AER synthetic generation in hardware for bio-inspired spiking systems

    Science.gov (United States)

    Linares-Barranco, Alejandro; Linares-Barranco, Bernabe; Jimenez-Moreno, Gabriel; Civit-Balcells, Anton

    2005-06-01

    Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows for real-time virtual massive connectivity between huge number neurons located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate 'events' according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. When building multi-chip muti-layered AER systems it is absolutely necessary to have a computer interface that allows (a) to read AER interchip traffic into the computer and visualize it on screen, and (b) convert conventional frame-based video stream in the computer into AER and inject it at some point of the AER structure. This is necessary for test and debugging of complex AER systems. This paper addresses the problem of converting, in a computer, a conventional frame-based video stream into the spike event based representation AER. There exist several proposed software methods for synthetic generation of AER for bio-inspired systems. This paper presents a hardware implementation for one method, which is based on Linear-Feedback-Shift-Register (LFSR) pseudo-random number generation. The sequence of events generated by this hardware, which follows a Poisson distribution like a biological neuron, has been reconstructed using two AER integrator cells. The error of reconstruction for a set of images that produces different traffic loads of event in the AER bus is used as evaluation criteria. A VHDL description of the method, that includes the Xilinx PCI Core, has been implemented and tested using a general purpose PCI-AER board. This PCI-AER board has been developed by authors, and uses

  2. Bio-inspired algorithms applied to molecular docking simulations.

    Science.gov (United States)

    Heberlé, G; de Azevedo, W F

    2011-01-01

    Nature as a source of inspiration has been shown to have a great beneficial impact on the development of new computational methodologies. In this scenario, analyses of the interactions between a protein target and a ligand can be simulated by biologically inspired algorithms (BIAs). These algorithms mimic biological systems to create new paradigms for computation, such as neural networks, evolutionary computing, and swarm intelligence. This review provides a description of the main concepts behind BIAs applied to molecular docking simulations. Special attention is devoted to evolutionary algorithms, guided-directed evolutionary algorithms, and Lamarckian genetic algorithms. Recent applications of these methodologies to protein targets identified in the Mycobacterium tuberculosis genome are described.

  3. HyperCell: A Bio-inspired Design Framework for Real-time Interactive Architectures

    Directory of Open Access Journals (Sweden)

    Jia-Rey Chang

    2018-01-01

    Full Text Available This pioneering research focuses on Biomimetic Interactive Architecture using “Computation”, “Embodiment”, and “Biology” to generate an intimate embodied convergence to propose a novel rule-based design framework for creating organic architectures composed of swarm-based intelligent components. Furthermore, the research boldly claims that Interactive Architecture should emerge as the next truly Organic Architecture. As the world and society are dynamically changing, especially in this digital era, the research dares to challenge the Utilitas, Firmitas, and Venustas of the traditional architectural Weltanschauung, and rejects them by adopting the novel notion that architecture should be dynamic, fluid, and interactive. This project reflects a trajectory from the 1960’s with the advent of the avant-garde architectural design group, Archigram, and its numerous intriguing and pioneering visionary projects. Archigram’s non-standard, mobile, and interactive projects profoundly influenced a new generation of architects to explore the connection between technology and their architectural projects. This research continues this trend of exploring novel design thinking and the framework of Interactive Architecture by discovering the interrelationship amongst three major topics: “Computation”, “Embodiment”, and “Biology”. The project aims to elucidate pioneering research combining these three topics in one discourse: “Bio-inspired digital architectural design”. These three major topics will be introduced in this Summary.   “Computation”, is any type of calculation that includes both arithmetical and nonarithmetical steps and follows a well-defined model understood and described as, for example, an algorithm. But, in this research, refers to the use of data storage, parametric design application, and physical computing for developing informed architectural designs. “Form” has always been the most critical focus in

  4. A bio-inspired apposition compound eye machine vision sensor system

    International Nuclear Information System (INIS)

    Davis, J D; Barrett, S F; Wright, C H G; Wilcox, M

    2009-01-01

    The Wyoming Information, Signal Processing, and Robotics Laboratory is developing a wide variety of bio-inspired vision sensors. We are interested in exploring the vision system of various insects and adapting some of their features toward the development of specialized vision sensors. We do not attempt to supplant traditional digital imaging techniques but rather develop sensor systems tailor made for the application at hand. We envision that many applications may require a hybrid approach using conventional digital imaging techniques enhanced with bio-inspired analogue sensors. In this specific project, we investigated the apposition compound eye and its characteristics commonly found in diurnal insects and certain species of arthropods. We developed and characterized an array of apposition compound eye-type sensors and tested them on an autonomous robotic vehicle. The robot exhibits the ability to follow a pre-defined target and avoid specified obstacles using a simple control algorithm.

  5. Bio-Inspired Human-Level Machine Learning

    Science.gov (United States)

    2015-10-25

    memory with DNA self-assembly. We showed that wet DNA computing can implement weighted-sum operations which are fundamental to perform pattern...artificial and real datasets as well as demonstrate preliminary wet experimental results using gel electrophoresis. In our classification results...according to the annealing temperature schedules. This shows how controlling the hybridization schedule influences both the positive definiteness

  6. Bio-inspired evaporation through plasmonic film of nanoparticles at the air-water interface.

    Science.gov (United States)

    Wang, Zhenhui; Liu, Yanming; Tao, Peng; Shen, Qingchen; Yi, Nan; Zhang, Fangyu; Liu, Quanlong; Song, Chengyi; Zhang, Di; Shang, Wen; Deng, Tao

    2014-08-27

    Plasmonic gold nanoparticles self-assembled at the air-water interface to produce an evaporative surface with local control inspired by skins and plant leaves. Fast and efficient evaporation is realized due to the instant and localized plasmonic heating at the evaporative surface. The bio-inspired evaporation process provides an alternative promising approach for evaporation, and has potential applications in sterilization, distillation, and heat transfer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Design and Analysis of a Bio-Inspired Wire-Driven Multi-Section Flexible Robot

    OpenAIRE

    Li, Zheng; Du, Ruxu

    2013-01-01

    This paper presents a bio-inspired wire-driven multi-section flexible robot. It is inspired by the snake skeleton and octopus arm muscle arrangements. The robot consists of three sections and each section is made up of several identical vertebras, which are articulated by both spherical joints and a flexible backbone. Each section is driven by two groups of wires, controlling the bending motion in X and Y directions. This design integrates the serpentine robots' structure and the continuum ro...

  8. Bio-Inspired Interaction Control of Robotic Machines for Motor Therapy

    OpenAIRE

    Zollo, Loredana; Formica, Domenico; Guglielmelli, Eugenio

    2007-01-01

    In this chapter basic criteria for the design and implementation of interaction control of robotic machines for motor therapy have been briefly introduced and two bio-inspired compliance control laws developed by the authors to address requirements coming from this specific application field have been presented. The two control laws are named the coactivation-based compliance control in the joint space and the torque-dependent compliance control in the joint space, respectively. They try to o...

  9. A Wireless Fatigue Monitoring System Utilizing a Bio-Inspired Tree Ring Data Tracking Technique

    OpenAIRE

    Bai, Shi; Li, Xuan; Xie, Zhaohui; Zhou, Zhi; Ou, Jinping

    2014-01-01

    Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is propo...

  10. An FEA study on impact resistance of bio-inspired CAD models

    OpenAIRE

    Page, T; Thorsteinsson, G

    2017-01-01

    The purpose of this paper is to explore the use of biomimetic methods in the design of armour systems. It focusses on biological structures found in nature that feature both rigid and flexible armours, analysing their structures and determining which are the most widely successful. A study was conducted on three bio-inspired structures built in Creo Parametric and tested using Finite Element Analysis (FEA) software to determine which structure had the best impact resistance. The study was con...

  11. A Bio-Inspired QoS-Oriented Handover Model in Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Daxin Tian

    2014-01-01

    Full Text Available We propose a bio-inspired model for making handover decision in heterogeneous wireless networks. It is based on an extended attractor selection model, which is biologically inspired by the self-adaptability and robustness of cellular response to the changes in dynamic environments. The goal of the proposed model is to guarantee multiple terminals’ satisfaction by meeting the QoS requirements of those terminals’ applications, and this model also attempts to ensure the fairness of network resources allocation, in the meanwhile, to enable the QoS-oriented handover decision adaptive to dynamic wireless environments. Some numerical simulations are preformed to validate our proposed bio-inspired model in terms of adaptive attractor selection in different noisy environments. And the results of some other simulations prove that the proposed handover scheme can adapt terminals’ network selection to the varying wireless environment and benefits the QoS of multiple terminal applications simultaneously and automatically. Furthermore, the comparative analysis also shows that the bio-inspired model outperforms the utility function based handover decision scheme in terms of ensuring a better QoS satisfaction and a better fairness of network resources allocation in dynamic heterogeneous wireless networks.

  12. Bio-Inspired Sustainability Assessment for Building Product Development—Concept and Case Study

    Directory of Open Access Journals (Sweden)

    Rafael Horn

    2018-01-01

    Full Text Available Technological advancement culminating in a globalized economy has brought tremendous improvements for mankind in manifold respects but comes at the cost of alienation from nature. Human activities nowadays are unsustainable and cause severe damage especially in terms of global depletion and destabilization of natural systems but also harm its own social resources. In this paper, a sustainability assessment method is developed based on a bio-inspired sustainability framework that has been developed in the project TRR 141-C01 “The biomimetic promise.” It is aims at regaining the advantages of societal embeddedness in its environment through biological inspiration. The method is developed using a structured approach including requirement specification, description of the inventory models on bio-inspiration and sustainability assessment, creation of a bio-inspired sustainability assessment model and its validation. It is defined as an accompanying assessment for decision support, using a six-fold two-dimensional structure of social, economic and environmental functions and burdens. The method is applied and validated in 6 projects of TRR 141 and its applicability is exemplarily shown by the assessment of “Bio-flexi”, a biobased and biodegradable natural fiber reinforced plastic composite for indoor cladding applications. Based on the findings of the application the assessment method itself is proposed to be advanced towards an adaptive structure and a consequent outlook is provided.

  13. Bio-inspired approach to multistage image processing

    Science.gov (United States)

    Timchenko, Leonid I.; Pavlov, Sergii V.; Kokryatskaya, Natalia I.; Poplavska, Anna A.; Kobylyanska, Iryna M.; Burdenyuk, Iryna I.; Wójcik, Waldemar; Uvaysova, Svetlana; Orazbekov, Zhassulan; Kashaganova, Gulzhan

    2017-08-01

    Multistage integration of visual information in the brain allows people to respond quickly to most significant stimuli while preserving the ability to recognize small details in the image. Implementation of this principle in technical systems can lead to more efficient processing procedures. The multistage approach to image processing, described in this paper, comprises main types of cortical multistage convergence. One of these types occurs within each visual pathway and the other between the pathways. This approach maps input images into a flexible hierarchy which reflects the complexity of the image data. The procedures of temporal image decomposition and hierarchy formation are described in mathematical terms. The multistage system highlights spatial regularities, which are passed through a number of transformational levels to generate a coded representation of the image which encapsulates, in a computer manner, structure on different hierarchical levels in the image. At each processing stage a single output result is computed to allow a very quick response from the system. The result is represented as an activity pattern, which can be compared with previously computed patterns on the basis of the closest match.

  14. Strong Quantum Confinement Effects and Chiral Excitons in Bio-Inspired ZnO–Amino Acid Cocrystals

    KAUST Repository

    Muhammed, Madathumpady Abubaker Habeeb; Lamers, Marlene; Baumann, Verena; Dey, Priyanka; Blanch, Adam J.; Polishchuk, Iryna; Kong, Xiang-Tian; Levy, Davide; Urban, Alexander S.; Govorov, Alexander O.; Pokroy, Boaz; Rodrí guez-Ferná ndez, Jessica; Feldmann, Jochen

    2018-01-01

    of amino acid potential barriers within the ZnO crystal lattice. Overall, our findings indicate that biomolecule cocrystallization can be used as a truly bio-inspired means to induce chiral quantum confinement effects in quasi-bulk semiconductors.

  15. Tribology of bio-inspired nanowrinkled films on ultrasoft substrates.

    Science.gov (United States)

    Lackner, Juergen M; Waldhauser, Wolfgang; Major, Lukasz; Teichert, Christian; Hartmann, Paul

    2013-01-01

    Biomimetic design of new materials uses nature as antetype, learning from billions of years of evolution. This work emphasizes the mechanical and tribological properties of skin, combining both hardness and wear resistance of its surface (the stratum corneum) with high elasticity of the bulk (epidermis, dermis, hypodermis). The key for combination of such opposite properties is wrinkling, being consequence of intrinsic stresses in the bulk (soft tissue): Tribological contact to counterparts below the stress threshold for tissue trauma occurs on the thick hard stratum corneum layer pads, while tensile loads smooth out wrinkles in between these pads. Similar mechanism offers high tribological resistance to hard films on soft, flexible polymers, which is shown for diamond-like carbon (DLC) and titanium nitride thin films on ultrasoft polyurethane and harder polycarbonate substrates. The choice of these two compared substrate materials will show that ultra-soft substrate materials are decisive for the distinct tribological material. Hierarchical wrinkled structures of films on these substrates are due to high intrinsic compressive stress, which evolves during high energetic film growth. Incremental relaxation of these stresses occurs by compound deformation of film and elastic substrate surface, appearing in hierarchical nano-wrinkles. Nano-wrinkled topographies enable high elastic deformability of thin hard films, while overstressing results in zigzag film fracture along larger hierarchical wrinkle structures. Tribologically, these fracture mechanisms are highly important for ploughing and sliding of sharp and flat counterparts on hard-coated ultra-soft substrates like polyurethane. Concentration of polyurethane deformation under the applied normal loads occurs below these zigzag cracks. Unloading closes these cracks again. Even cyclic testing do not lead to film delamination and retain low friction behavior, if the adhesion to the substrate is high and the initial

  16. TRIBOLOGY OF BIO-INSPIRED NANOWRINKLED FILMS ON ULTRASOFT SUBSTRATES

    Directory of Open Access Journals (Sweden)

    Juergen M. Lackner

    2013-03-01

    Full Text Available Biomimetic design of new materials uses nature as antetype, learning from billions of years of evolution. This work emphasizes the mechanical and tribological properties of skin, combining both hardness and wear resistance of its surface (the stratum corneum with high elasticity of the bulk (epidermis, dermis, hypodermis. The key for combination of such opposite properties is wrinkling, being consequence of intrinsic stresses in the bulk (soft tissue: Tribological contact to counterparts below the stress threshold for tissue trauma occurs on the thick hard stratum corneum layer pads, while tensile loads smooth out wrinkles in between these pads. Similar mechanism offers high tribological resistance to hard films on soft, flexible polymers, which is shown for diamond-like carbon (DLC and titanium nitride thin films on ultrasoft polyurethane and harder polycarbonate substrates. The choice of these two compared substrate materials will show that ultra-soft substrate materials are decisive for the distinct tribological material. Hierarchical wrinkled structures of films on these substrates are due to high intrinsic compressive stress, which evolves during high energetic film growth. Incremental relaxation of these stresses occurs by compound deformation of film and elastic substrate surface, appearing in hierarchical nano-wrinkles. Nano-wrinkled topographies enable high elastic deformability of thin hard films, while overstressing results in zigzag film fracture along larger hierarchical wrinkle structures. Tribologically, these fracture mechanisms are highly important for ploughing and sliding of sharp and flat counterparts on hard-coated ultra-soft substrates like polyurethane. Concentration of polyurethane deformation under the applied normal loads occurs below these zigzag cracks. Unloading closes these cracks again. Even cyclic testing do not lead to film delamination and retain low friction behavior, if the adhesion to the substrate is high

  17. Bio-Inspired Neural Model for Learning Dynamic Models

    Science.gov (United States)

    Duong, Tuan; Duong, Vu; Suri, Ronald

    2009-01-01

    A neural-network mathematical model that, relative to prior such models, places greater emphasis on some of the temporal aspects of real neural physical processes, has been proposed as a basis for massively parallel, distributed algorithms that learn dynamic models of possibly complex external processes by means of learning rules that are local in space and time. The algorithms could be made to perform such functions as recognition and prediction of words in speech and of objects depicted in video images. The approach embodied in this model is said to be "hardware-friendly" in the following sense: The algorithms would be amenable to execution by special-purpose computers implemented as very-large-scale integrated (VLSI) circuits that would operate at relatively high speeds and low power demands.

  18. Bio-Inspired Protein-Based Nanoformulations for Cancer Theranostics

    Directory of Open Access Journals (Sweden)

    Yi Gou

    2018-04-01

    Full Text Available Over the past decade, more interests have been aroused in engineering protein-based nanoformulations for cancer treatment. This excitement originates from the success of FDA approved Abraxane (Albumin-based paclitaxel nanoparticles in 2005. The new generation of biocompatible endogenous protein-based nanoformulations is currently constructed through delivering cancer therapeutic and diagnostic agents simultaneously, as named potential theranostics. Protein nanoformulations are commonly incorporated with dyes, contrast agents, drug payloads or inorganic nanoclusters, serving as imaging-guided combinatorial cancer therapeutics. Employing the nature identity of proteins, the theranostics, escape the clearance by reticuloendothelial cells and have a long blood circulation time. The nanoscale sizet allows them to be penetrated deeply into tumor tissues. In addition, stimuli release and targeted molecules are incorporated to improve the delivery efficiency. The ongoing advancement of protein-based nanoformulations for cancer theranostics in recent 5 years is reviewed in this paper. Fine-designed nanoformulations based on albumin, ferritin, gelatin, and transferrin are highlighted from the literature. Finally, the current challenges are identified in translating protein-based nanoformulations from laboratory to clinical trials.

  19. Bio-Inspired Microsystem for Robust Genetic Assay Recognition

    Directory of Open Access Journals (Sweden)

    Jaw-Chyng Lue

    2008-01-01

    Full Text Available A compact integrated system-on-chip (SoC architecture solution for robust, real-time, and on-site genetic analysis has been proposed. This microsystem solution is noise-tolerable and suitable for analyzing the weak fluorescence patterns from a PCR prepared dual-labeled DNA microchip assay. In the architecture, a preceding VLSI differential logarithm microchip is designed for effectively computing the logarithm of the normalized input fluorescence signals. A posterior VLSI artificial neural network (ANN processor chip is used for analyzing the processed signals from the differential logarithm stage. A single-channel logarithmic circuit was fabricated and characterized. A prototype ANN chip with unsupervised winner-take-all (WTA function was designed, fabricated, and tested. An ANN learning algorithm using a novel sigmoid-logarithmic transfer function based on the supervised backpropagation (BP algorithm is proposed for robustly recognizing low-intensity patterns. Our results show that the trained new ANN can recognize low-fluorescence patterns better than an ANN using the conventional sigmoid function.

  20. Bio-inspired step-climbing in a hexapod robot

    International Nuclear Information System (INIS)

    Chou, Ya-Cheng; Yu, Wei-Shun; Huang, Ke-Jung; Lin, Pei-Chun

    2012-01-01

    Inspired by the observation that the cockroach changes from a tripod gait to a different gait for climbing high steps, we report on the design and implementation of a novel, fully autonomous step-climbing maneuver, which enables a RHex-style hexapod robot to reliably climb a step up to 230% higher than the length of its leg. Similar to the climbing strategy most used by cockroaches, the proposed maneuver is composed of two stages. The first stage is the ‘rearing stage,’ inclining the body so the front side of the body is raised and it is easier for the front legs to catch the top of the step, followed by the ‘rising stage,’ maneuvering the body's center of mass to the top of the step. Two infrared range sensors are installed on the front of the robot to detect the presence of the step and its orientation relative to the robot's heading, so that the robot can perform automatic gait transition, from walking to step-climbing, as well as correct its initial tilt approaching posture. An inclinometer is utilized to measure body inclination and to compute step height, thus enabling the robot to adjust its gait automatically, in real time, and to climb steps of different heights and depths successfully. The algorithm is applicable for the robot to climb various rectangular obstacles, including a narrow bar, a bar and a step (i.e. a bar of infinite width). The performance of the algorithm is evaluated experimentally, and the comparison of climbing strategies and climbing behaviors in biological and robotic systems is discussed. (paper)

  1. Bio-inspired spiking neural network for nonlinear systems control.

    Science.gov (United States)

    Pérez, Javier; Cabrera, Juan A; Castillo, Juan J; Velasco, Juan M

    2018-08-01

    Spiking neural networks (SNN) are the third generation of artificial neural networks. SNN are the closest approximation to biological neural networks. SNNs make use of temporal spike trains to command inputs and outputs, allowing a faster and more complex computation. As demonstrated by biological organisms, they are a potentially good approach to designing controllers for highly nonlinear dynamic systems in which the performance of controllers developed by conventional techniques is not satisfactory or difficult to implement. SNN-based controllers exploit their ability for online learning and self-adaptation to evolve when transferred from simulations to the real world. SNN's inherent binary and temporary way of information codification facilitates their hardware implementation compared to analog neurons. Biological neural networks often require a lower number of neurons compared to other controllers based on artificial neural networks. In this work, these neuronal systems are imitated to perform the control of non-linear dynamic systems. For this purpose, a control structure based on spiking neural networks has been designed. Particular attention has been paid to optimizing the structure and size of the neural network. The proposed structure is able to control dynamic systems with a reduced number of neurons and connections. A supervised learning process using evolutionary algorithms has been carried out to perform controller training. The efficiency of the proposed network has been verified in two examples of dynamic systems control. Simulations show that the proposed control based on SNN exhibits superior performance compared to other approaches based on Neural Networks and SNNs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Bio-inspired UAV routing, source localization, and acoustic signature classification for persistent surveillance

    Science.gov (United States)

    Burman, Jerry; Hespanha, Joao; Madhow, Upamanyu; Pham, Tien

    2011-06-01

    A team consisting of Teledyne Scientific Company, the University of California at Santa Barbara and the Army Research Laboratory* is developing technologies in support of automated data exfiltration from heterogeneous battlefield sensor networks to enhance situational awareness for dismounts and command echelons. Unmanned aerial vehicles (UAV) provide an effective means to autonomously collect data from a sparse network of unattended ground sensors (UGSs) that cannot communicate with each other. UAVs are used to reduce the system reaction time by generating autonomous collection routes that are data-driven. Bio-inspired techniques for search provide a novel strategy to detect, capture and fuse data. A fast and accurate method has been developed to localize an event by fusing data from a sparse number of UGSs. This technique uses a bio-inspired algorithm based on chemotaxis or the motion of bacteria seeking nutrients in their environment. A unique acoustic event classification algorithm was also developed based on using swarm optimization. Additional studies addressed the problem of routing multiple UAVs, optimally placing sensors in the field and locating the source of gunfire at helicopters. A field test was conducted in November of 2009 at Camp Roberts, CA. The field test results showed that a system controlled by bio-inspired software algorithms can autonomously detect and locate the source of an acoustic event with very high accuracy and visually verify the event. In nine independent test runs of a UAV, the system autonomously located the position of an explosion nine times with an average accuracy of 3 meters. The time required to perform source localization using the UAV was on the order of a few minutes based on UAV flight times. In June 2011, additional field tests of the system will be performed and will include multiple acoustic events, optimal sensor placement based on acoustic phenomenology and the use of the International Technology Alliance (ITA

  3. A bio-inspired approach for in situ synthesis of tunable adhesive

    International Nuclear Information System (INIS)

    Sun, Leming; Yi, Sijia; Wang, Yongzhong; Pan, Kang; Zhong, Qixin; Zhang, Mingjun

    2014-01-01

    Inspired by the strong adhesive produced by English ivy, this paper proposes an in situ synthesis approach for fabricating tunable nanoparticle enhanced adhesives. Special attention was given to tunable features of the adhesive produced by the biological process. Parameters that may be used to tune properties of the adhesive will be proposed. To illustrate and validate the proposed approach, an experimental platform was presented for fabricating tunable chitosan adhesive enhanced by Au nanoparticles synthesized in situ. This study contributes to a bio-inspired approach for in situ synthesis of tunable nanocomposite adhesives by mimicking the natural biological processes of ivy adhesive synthesis. (paper)

  4. Autonomic networking-on-chip bio-inspired specification, development, and verification

    CERN Document Server

    Cong-Vinh, Phan

    2011-01-01

    Despite the growing mainstream importance and unique advantages of autonomic networking-on-chip (ANoC) technology, Autonomic Networking-On-Chip: Bio-Inspired Specification, Development, and Verification is among the first books to evaluate research results on formalizing this emerging NoC paradigm, which was inspired by the human nervous system. The FIRST Book to Assess Research Results, Opportunities, & Trends in ""BioChipNets"" The third book in the Embedded Multi-Core Systems series from CRC Press, this is an advanced technical guide and reference composed of contributions from prominent re

  5. A bio-inspired high-authority actuator for shape morphing structures

    Science.gov (United States)

    Elzey, Dana M.; Sofla, Aarash Y. N.; Wadley, Haydn N. G.

    2003-08-01

    Lightweight structures capable of changing their shape on demand are of interest for a number of applications, including aerospace, power generation, and undersea vehicles. This paper describes a bio-inspired cellular metal vertebrate structure which relies on shape memory alloy (SMA) faces to achieve fully reversing shape change. The resulting vertebrate actuators can be combined with flexible face sheets to create a load-bearing, shape morphing panel. Performance of the vertebrate actuator in terms of maximum curvature and moment is analyzed and discussed. A recently constructed, prototype shape morphing airfoil is used to illustrate the concept.

  6. Bio-inspiring cyber security and cloud services trends and innovations

    CERN Document Server

    Kim, Tai-Hoon; Kacprzyk, Janusz; Awad, Ali

    2014-01-01

    This volume presents recent research in cyber security, and reports how organizations can gain competitive advantages by applying the different security techniques in real-world scenarios. The volume provides reviews of cutting–edge technologies, algorithms, applications and insights for bio-inspiring cyber security-based systems. The book will be a valuable companion and comprehensive reference for both postgraduate and senior undergraduate students who are taking a course in cyber security. The volume is organized in self-contained chapters to provide greatest reading flexibility.  

  7. Facile creation of bio-inspired superhydrophobic Ce-based metallic glass surfaces

    Science.gov (United States)

    Liu, Kesong; Li, Zhou; Wang, Weihua; Jiang, Lei

    2011-12-01

    A bio-inspired synthesis strategy was conducted to fabricate superhydrophobic Ce-based bulk metallic glass (BMG) surfaces with self-cleaning properties. Micro-nanoscale hierarchical structures were first constructed on BMG surfaces and then modified with the low surface energy coating. Surface structures, surface chemical compositions, and wettability were characterized by combining scanning electron microscopy, atomic force microscopy, x-ray photoelectron spectroscopy, and contact angle measurements. Research indicated that both surface multiscale structures and the low surface free energy coating result in the final formation of superhydrophobicity.

  8. Bio-inspired, subwavelength surface structures to control reflectivity, transmission, and scattering in the infrared

    Science.gov (United States)

    Lora Gonzalez, Federico

    Controlling the reflection of visible and infrared (IR) light at interfaces is extremely important to increase the power efficiency and performance of optics, electro-optical and (thermo)photovoltaic systems. The eye of the moth has evolved subwavelength protuberances that increase light transmission into the eye tissue and prevent reflection. The subwavelength protuberances effectively grade the refractive index from that of air (n=1) to that of the tissue (n=1.4), making the interface gradual, suppressing reflection. In theory, the moth-eye (ME) structures can be implemented with any material platform to achieve an antireflectance effect by scaling the pitch and size of protuberances for the wavelength range of interest. In this work, a bio-inspired, scalable and substrate-independent surface modification protocol was developed to realize broadband antireflective structures based on the moth-eye principle. Quasi-ordered ME arrays were fabricated in IR relevant materials using a colloidal lithography method to achieve highly efficient, omni-directional transmission of mid and far infrared (IR) radiation. The effect of structure height and aspect ratio on transmittance and scattering is explored, with discussion on experimental techniques and effective medium theory (EMT). The highest aspect ratio structures (AR = 9.4) achieved peak single-side transmittance of 98%, with >85% transmission for lambda = 7--30 microns. A detailed photon balance constructed by transmission, forward scattering, specular reflection and diffuse reflection measurements to quantify optical losses due to near-field effects will be discussed. In addition, angle-dependent transmission measurements showed that moth-eye structures provide superior antireflective properties compared to unstructured interfaces over a wide angular range (0--60° incidence). Finally, subwavelength ME structures are incorporated on a Si substrate to enhance the absorption of near infrared (NIR) light in PtSi films to

  9. Bio-inspired hybrid microelectrodes: a hybrid solution to improve long-term performance of chronic intracortical implants.

    Science.gov (United States)

    De Faveri, Sara; Maggiolini, Emma; Miele, Ermanno; De Angelis, Francesco; Cesca, Fabrizia; Benfenati, Fabio; Fadiga, Luciano

    2014-01-01

    The use of implants that allow chronic electrical stimulation and recording in the brain of human patients is currently limited by a series of events that cause the deterioration over time of both the electrode surface and the surrounding tissue. The main reason of failure is the tissue inflammatory reaction that eventually causes neuronal loss and glial encapsulation, resulting in a progressive increase of the electrode-electrolyte impedance. Here, we describe a new method to create bio-inspired electrodes to mimic the mechanical properties and biological composition of the host tissue. This combination has a great potential to increase the implant lifetime by reducing tissue reaction and improving electrical coupling. Our method implies coating the electrode with reprogrammed neural or glial cells encapsulated within a hydrogel layer. We chose fibrin as a hydrogel and primary hippocampal neurons or astrocytes from rat brain as cellular layer. We demonstrate that fibrin coating is highly biocompatible, forms uniform coatings of controllable thickness, does not alter the electrochemical properties of the microelectrode and allows good quality recordings. Moreover, it reduces the amount of host reactive astrocytes - over time - compared to a bare wire and is fully reabsorbed by the surrounding tissue within 7 days after implantation, avoiding the common problem of hydrogels swelling. Both astrocytes and neurons could be successfully grown onto the electrode surface within the fibrin hydrogel without altering the electrochemical properties of the microelectrode. This bio-hybrid device has therefore a good potential to improve the electrical integration at the neuron-electrode interface and support the long-term success of neural prostheses.

  10. Bio-inspired hybrid microelectrodes. A hybrid solution to improve long-term performance of chronic intracortical implants.

    Directory of Open Access Journals (Sweden)

    Sara eDe Faveri

    2014-04-01

    Full Text Available The use of implants that allow chronic electrical stimulation and recording in the brain of human patients is currently limited by a series of events that cause the deterioration over time of both the electrode surface and the surrounding tissue. The main reason of failure is the tissue inflammatory reaction that eventually causes neuronal loss and glial encapsulation, resulting in a progressive increase of the electrode-electrolyte impedance. Here, we describe a new method to create bio-inspired electrodes to mimic the mechanical properties and biological composition of the host tissue. This combination has a great potential to increase the implant lifetime by reducing tissue reaction and improving electrical coupling. Our method implies coating the electrode with reprogrammed neural or glial cells encapsulated within a hydrogel layer. We chose fibrin as a hydrogel and primary hippocampal neurons or astrocytes from rat brain as cellular layer. We demonstrate that fibrin coating is highly biocompatible, forms uniform coatings of controllable thickness, does not alter the electrochemical properties of the microelectrode and allows good quality recordings. Moreover, it reduces the amount of host reactive astrocytes - over time - compared to a bare wire and is fully reabsorbed by the surrounding tissue within 7 days after implantation, avoiding the common problem of hydrogels swelling. Both astrocytes and neurons could be successfully grown onto the electrode surface within the fibrin hydrogel without altering the electrochemical properties of the microelectrode. This bio-hybrid device has therefore a good potential to improve the electrical integration at the neuron-electrode interface and support the long-term success of neural prostheses.

  11. A Review on Development and Applications of Bio-Inspired Superhydrophobic Textiles

    Science.gov (United States)

    Ahmad, Ishaq; Kan, Chi-wai

    2016-01-01

    Bio-inspired engineering has been envisioned in a wide array of applications. All living bodies on Earth, including animals and plants, have well organized functional systems developed by nature. These naturally designed functional systems inspire scientists and engineers worldwide to mimic the system for practical applications by human beings. Researchers in the academic world and industries have been trying, for hundreds of years, to demonstrate how these natural phenomena could be translated into the real world to save lives, money and time. One of the most fascinating natural phenomena is the resistance of living bodies to contamination by dust and other pollutants, thus termed as self-cleaning phenomenon. This phenomenon has been observed in many plants, animals and insects and is termed as the Lotus Effect. With advancement in research and technology, attention has been given to the exploration of the underlying mechanisms of water repellency and self-cleaning. As a result, various concepts have been developed including Young’s equation, and Wenzel and Cassie–Baxter theories. The more we unravel this process, the more we get access to its implications and applications. A similar pursuit is emphasized in this review to explain the fundamental principles, mechanisms, past experimental approaches and ongoing research in the development of bio-inspired superhydrophobic textiles. PMID:28774012

  12. New development thoughts on the bio-inspired intelligence based control for unmanned combat aerial vehicle

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Bio-inspired intelligence is in the spotlight in the field of international artificial intelligence,and unmanned combat aerial vehicle(UCAV),owing to its potential to perform dangerous,repetitive tasks in remote and hazardous,is very promising for the technological leadership of the nation and essential for improving the security of society.On the basis of introduction of bioinspired intelligence and UCAV,a series of new development thoughts on UCAV control are proposed,including artificial brain based high-level autonomous control for UCAV,swarm intelligence based cooperative control for multiple UCAVs,hy-brid swarm intelligence and Bayesian network based situation assessment under complicated combating environments, bio-inspired hardware based high-level autonomous control for UCAV,and meta-heuristic intelligence based heterogeneous cooperative control for multiple UCAVs and unmanned combat ground vehicles(UCGVs).The exact realization of the proposed new development thoughts can enhance the effectiveness of combat,while provide a series of novel breakthroughs for the intelligence,integration and advancement of future UCAV systems.

  13. Three-dimensional trajectory tracking for underactuated AUVs with bio-inspired velocity regulation

    Directory of Open Access Journals (Sweden)

    Jiajia Zhou

    2018-05-01

    Full Text Available This paper attempts to address the motion parameter skip problem associated with three-dimensional trajectory tracking of an underactuated Autonomous Underwater Vehicle (AUV using backstepping-based control, due to the unsmoothness of tracking trajectory. Through kinematics concepts, a three-dimensional dynamic velocity regulation controller is derived. This controller makes use of the surge and angular velocity errors with bio-inspired models and backstepping techniques. It overcomes the frequently occurring problem of parameter skip at inflection point existing in backstepping tracking control method and increases system robustness. Moreover, the proposed method can effectively avoid the singularity problem in backstepping control of virtual velocity error. The control system is proved to be uniformly ultimately bounded using Lyapunov stability theory. Simulation results illustrate the effectiveness and efficiency of the developed controller, which can realize accurate three-dimensional trajectory tracking for an underactuated AUV with constant external disturbances. Keywords: Dynamic velocity regulation, Bio-inspired model, Backstepping, Underactuated AUV, Three-dimensional trajectory tracking

  14. Nature as an engineer: one simple concept of a bio-inspired functional artificial muscle

    International Nuclear Information System (INIS)

    Schmitt, S; Haeufle, D F B; Günther, M; Blickhan, R

    2012-01-01

    The biological muscle is a powerful, flexible and versatile actuator. Its intrinsic characteristics determine the way how movements are generated and controlled. Robotic and prosthetic applications expect to profit from relying on bio-inspired actuators which exhibit natural (muscle-like) characteristics. As of today, when constructing a technical actuator, it is not possible to copy the exact molecular structure of a biological muscle. Alternatively, the question may be put how its characteristics can be realized with known mechanical components. Recently, a mechanical construct for an artificial muscle was proposed, which exhibits hyperbolic force–velocity characteristics. In this paper, we promote the constructing concept which is made by substantiating the mechanical design of biological muscle by a simple model, proving the feasibility of its real-world implementation, and checking their output both for mutual consistency and agreement with biological measurements. In particular, the relations of force, enthalpy rate and mechanical efficiency versus contraction velocity of both the construct’s technical implementation and its numerical model were determined in quick-release experiments. All model predictions for these relations and the hardware results are now in good agreement with the biological literature. We conclude that the construct represents a mechanical concept of natural actuation, which is suitable for laying down some useful suggestions when designing bio-inspired actuators. (paper)

  15. Bio-Inspired Control of an Arm Exoskeleton Joint with Active-Compliant Actuation System

    Directory of Open Access Journals (Sweden)

    Michele Folgheraiter

    2009-01-01

    Full Text Available This paper presents the methodology followed on the design of a multi-contact point haptic interface that uses a bio-inspired control approach and a novel actuation system. The combination of these components aims at creating a system that increases the operability of the target, and, at the same time, enables an intuitive and safe tele-operation of any complex robotic system of any given morphology. The novelty lies on the combination of a thoughtful kinematic structure driven by an active-compliant actuation system and a bio-inspired paradigm for its regulation. Due to the proposed actuation approach, the final system will achieve the condition of wearable system. On that final solution, each joint will be able to change its stiffness depending on the task to be executed, and on the anatomical features of each individual. Moreover, the system provides a variety of safety mechanisms at different levels to prevent causing any harm to the operator. In future, the system should allow the complete virtual immersion of the user within the working scenario.

  16. A Review on Development and Applications of Bio-Inspired Superhydrophobic Textiles

    Directory of Open Access Journals (Sweden)

    Ishaq Ahmad

    2016-11-01

    Full Text Available Bio-inspired engineering has been envisioned in a wide array of applications. All living bodies on Earth, including animals and plants, have well organized functional systems developed by nature. These naturally designed functional systems inspire scientists and engineers worldwide to mimic the system for practical applications by human beings. Researchers in the academic world and industries have been trying, for hundreds of years, to demonstrate how these natural phenomena could be translated into the real world to save lives, money and time. One of the most fascinating natural phenomena is the resistance of living bodies to contamination by dust and other pollutants, thus termed as self-cleaning phenomenon. This phenomenon has been observed in many plants, animals and insects and is termed as the Lotus Effect. With advancement in research and technology, attention has been given to the exploration of the underlying mechanisms of water repellency and self-cleaning. As a result, various concepts have been developed including Young’s equation, and Wenzel and Cassie–Baxter theories. The more we unravel this process, the more we get access to its implications and applications. A similar pursuit is emphasized in this review to explain the fundamental principles, mechanisms, past experimental approaches and ongoing research in the development of bio-inspired superhydrophobic textiles.

  17. Nature as an engineer: one simple concept of a bio-inspired functional artificial muscle.

    Science.gov (United States)

    Schmitt, S; Haeufle, D F B; Blickhan, R; Günther, M

    2012-09-01

    The biological muscle is a powerful, flexible and versatile actuator. Its intrinsic characteristics determine the way how movements are generated and controlled. Robotic and prosthetic applications expect to profit from relying on bio-inspired actuators which exhibit natural (muscle-like) characteristics. As of today, when constructing a technical actuator, it is not possible to copy the exact molecular structure of a biological muscle. Alternatively, the question may be put how its characteristics can be realized with known mechanical components. Recently, a mechanical construct for an artificial muscle was proposed, which exhibits hyperbolic force-velocity characteristics. In this paper, we promote the constructing concept which is made by substantiating the mechanical design of biological muscle by a simple model, proving the feasibility of its real-world implementation, and checking their output both for mutual consistency and agreement with biological measurements. In particular, the relations of force, enthalpy rate and mechanical efficiency versus contraction velocity of both the construct's technical implementation and its numerical model were determined in quick-release experiments. All model predictions for these relations and the hardware results are now in good agreement with the biological literature. We conclude that the construct represents a mechanical concept of natural actuation, which is suitable for laying down some useful suggestions when designing bio-inspired actuators.

  18. Energy evaluation of a bio-inspired gait modulation method for quadrupedal locomotion.

    Science.gov (United States)

    Fukuoka, Yasuhiro; Fukino, Kota; Habu, Yasushi; Mori, Yoshikazu

    2015-08-04

    We have proposed a bio-inspired gait modulation method, by means of which a simulated quadruped model can successfully perform smooth, autonomous gait transitions from a walk to a trot to a gallop, as observed in animals. The model is equipped with a rhythm generator called a central pattern generator (CPG) for each leg. The lateral neighbouring CPGs are mutually and inhibitorily coupled, and the CPG network is hardwired to produce a trot. Adding only the simple feedback of body tilt to each CPG, which was based on input from the postural reflex, led to the emergence of un-programmed walking and galloping at low and high speeds, respectively. Although this autonomous gait transition was a consequence of postural adaptation, it coincidentally also resulted in the minimization of energy consumption, as observed in real animals. In simulations at a variety of constant speeds the energy cost was lower for walking at low speeds and for galloping at high speeds than it was for trotting. Moreover, each gait transition occurred at the optimal speed, such that the model minimised its energy consumption. Thus, gait transitions in simulations that included the bio-inspired gait modulation method were similar to those observed in animals, even from the perspective of energy consumption. This method should therefore be a preferred choice for motion generation and control in biomimetic quadrupedal locomotion.

  19. Performance Characteristics of Bio-Inspired Metal Nanostructures as Surface-Enhanced Raman Scattered (SERS) Substrates.

    Science.gov (United States)

    Areizaga-Martinez, Hector I; Kravchenko, Ivan; Lavrik, Nickolay V; Sepaniak, Michael J; Hernández-Rivera, Samuel P; De Jesús, Marco A

    2016-09-01

    The fabrication of high-performance plasmonic nanomaterials for bio-sensing and trace chemical detection is a field of intense theoretical and experimental research. The use of metal-silicon nanopillar arrays as analytical sensors has been reported with reasonable results in recent years. The use of bio-inspired nanocomposite structures that follow the Fibonacci numerical architecture offers the opportunity to develop nanostructures with theoretically higher and more reproducible plasmonic fields over extended areas. The work presented here describes the nanofabrication process for a series of 40 µm × 40 µm bio-inspired arrays classified as asymmetric fractals (sunflower seeds and romanesco broccoli), bilaterally symmetric (acacia leaves and honeycombs), and radially symmetric (such as orchids and lily flowers) using electron beam lithography. In addition, analytical capabilities were evaluated using surface-enhanced Raman scattering (SERS). The substrate characterization and SERS performance of the developed substrates as the strategies to assess the design performance are presented and discussed. © The Author(s) 2016.

  20. Multiple Decoupled CPGs with Local Sensory Feedback for Adaptive Locomotion Behaviors of Bio-inspired Walking Robots

    DEFF Research Database (Denmark)

    Shaker Barikhan, Subhi; Wörgötter, Florentin; Manoonpong, Poramate

    2014-01-01

    , and their interactions during body and leg movements through the environment. Based on this concept, we present here an artificial bio-inspired walking system. Its intralimb coordination is formed by multiple decoupled CPGs while its interlimb coordination is attained by the interactions between body dynamics...... and the environment through local sensory feedback of each leg. Simulation results show that this bio-inspired approach generates self-organizing emergent locomotion allowing the robot to adaptively form regular patterns, to stably walk while pushing an object with its front legs or performing multiple stepping...

  1. A bio-inspired methodology of identifying influential nodes in complex networks.

    Directory of Open Access Journals (Sweden)

    Cai Gao

    Full Text Available How to identify influential nodes is a key issue in complex networks. The degree centrality is simple, but is incapable to reflect the global characteristics of networks. Betweenness centrality and closeness centrality do not consider the location of nodes in the networks, and semi-local centrality, leaderRank and pageRank approaches can be only applied in unweighted networks. In this paper, a bio-inspired centrality measure model is proposed, which combines the Physarum centrality with the K-shell index obtained by K-shell decomposition analysis, to identify influential nodes in weighted networks. Then, we use the Susceptible-Infected (SI model to evaluate the performance. Examples and applications are given to demonstrate the adaptivity and efficiency of the proposed method. In addition, the results are compared with existing methods.

  2. Design and development of bio-inspired framework for reservoir operation optimization

    Science.gov (United States)

    Asvini, M. Sakthi; Amudha, T.

    2017-12-01

    Frameworks for optimal reservoir operation play an important role in the management of water resources and delivery of economic benefits. Effective utilization and conservation of water from reservoirs helps to manage water deficit periods. The main challenge in reservoir optimization is to design operating rules that can be used to inform real-time decisions on reservoir release. We develop a bio-inspired framework for the optimization of reservoir release to satisfy the diverse needs of various stakeholders. In this work, single-objective optimization and multiobjective optimization problems are formulated using an algorithm known as "strawberry optimization" and tested with actual reservoir data. Results indicate that well planned reservoir operations lead to efficient deployment of the reservoir water with the help of optimal release patterns.

  3. Bio-Inspired Energy-Aware Protocol Design for Cooperative Wireless Networks

    DEFF Research Database (Denmark)

    Perrucci, Gian Paolo; Anggraeni, Puri Novelti; Wardana, Satya Ardhy

    2011-01-01

    In this work, bio-inspired cooperation rules are applied to wireless communication networks. The main goal is to derive cooperative behaviour rules to improve the energy consumption of each mobile device. A medium access control (MAC) protocol particularly designed for peer-to-peer communication...... be achieved by this architecture using game theoretic approaches. As an extension, this work explores the impact of the MAC protocol on the power saving capabilities. This result shows that standard MAC mechanisms are not optimised for the considered cooperative setup. A new MAC protocol is proposed...... among cooperative wireless mobile devices is described. The work is based on a novel communication architecture, where a group of mobile devices are connected both to a cellular base station and among them using short-range communication links. A prior work has investigated the energy saving that can...

  4. Flow around an autonomous underwater vehicle with bio-inspired coating

    Science.gov (United States)

    Watkins, Scott; Montoya-Segnini, Jose; Bocanegra Evans, Humberto; Curet, Oscar; Gorumlu, Serdar; Aksak, Burak; Kazemi, Amirkhosro; Chamorro, Leonardo; Castillo, Luciano

    2017-11-01

    Flow separation plays a major factor in the form drag of a moving object. In particular, suppressing or reducing flow separation is critical in the energy expenditure of autonomous underwater vehicles. Previous research suggests that bio-inspired micro-fibrillar structures are capable of reducing the boundary layer separation in a turbulent flow. Here, we present laboratory measurements using PIV near the wall and in the wake of two submersible vessel models; one had a coating composed of ordered fibers, and the other had smooth walls. Flow characterization with planar PIV included the presence or absence of a tail fin at multiple angles of attack of the vessels. Preliminary results reveal changes of the flow in the wake of the vessel with coating resulting in lower or similar velocity deficit in the wake compared to the smooth vessel.

  5. Design and development of a bio-inspired, under-actuated soft gripper.

    Science.gov (United States)

    Hassan, Taimoor; Manti, Mariangela; Passetti, Giovanni; d'Elia, Nicolò; Cianchetti, Matteo; Laschi, Cecilia

    2015-08-01

    The development of robotic devices able to perform manipulation tasks mimicking the human hand has been assessed on large scale. This work stands in the challenging scenario where soft materials are combined with bio-inspired design in order to develop soft grippers with improved grasping and holding capabilities. We are going to show a low-cost, under-actuated and adaptable soft gripper, highlighting the design and the manufacturing process. In particular, a critical analysis is made among three versions of the gripper with same design and actuation mechanism, but based on different materials. A novel actuation principle has been implemented in both cases, in order to reduce the encumbrance of the entire system and improve its aesthetics. Grasping and holding capabilities have been tested for each device, with target objects varying in shape, size and material. Results highlight synergy between the geometry and the intrinsic properties of the soft material, showing the way to novel design principles for soft grippers.

  6. INVESTIGATING PECTORAL SHAPES AND LOCOMOTIVE STRATEGIES FOR CONCEPTUAL DESIGNING BIO-INSPIRED ROBOTIC FISH

    Directory of Open Access Journals (Sweden)

    A. I. MAINONG

    2017-01-01

    Full Text Available This paper describes the performance analysis of a conceptual bio-inspired robotic fish design, which is based on the morphology similar to the boxfish (Ostracion melagris. The robotic fish prototype is driven by three micro servos; two on the pectoral fins, and one on the caudal fin. Two electronic rapid prototyping boards were employed; one for the movement of robotic fish, and one for the force sensors measurements. The robotic fish were built using fused deposition modeling (FDM, more popularly known as the 3D printing method. Several designs of pectoral fins (rectangular, triangular and quarter-ellipse with unchanging the value of aspect ratio (AR employed to measure the performance of the prototype robotic fish in terms of hydrodynamics, thrust and maneuvering characteristics. The analysis of the unmanned robotic system performance is made experimentally and the results show that the proposed bioinspired robotic prototype opens up the possibility of design optimization research for future work.

  7. Bio-Inspired Design and Kinematic Analysis of Dung Beetle-Like Legs

    DEFF Research Database (Denmark)

    Aditya, Sai Krishna Venkata; Ignasov, Jevgeni; Filonenko, Konstantin

    2017-01-01

    The African dung beetle Scarabaeus galenus can use its front legs to walk and manipulate or form a dung ball. The interesting multifunctional legs have not been fully investigated or even used as inspiration for robot leg design. Thus, in this paper, we present the development of real dung beetle......-like front legs based on biological investigation. As a result, each leg consists of three main segments which were built using 3D printing. The segments were combined with in total four active DOFs in order to mimic locomotion and object manipulation of the beetle. Kinematics analysis of the leg was also...... performed to identify its workspace as well as to design its trajectory. To this end, the study contributes not only novel multifunctional robotic legs but also the methodology of the bio-inspired leg design....

  8. Bio-inspired synthesis and characterization of superparamagnetic particles; Sintese e caracterizacao bioinspirada de particulas superparamagneticas

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Vinicius F., E-mail: vfc_mg@yahoo.com.br [Universidade Federal de Itajuba (UNIFEI), MG (Brazil); Queiroz, Alvaro A.A. [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Centro de Estudos e Inovacao em Materiais Biofuncionais Avancados

    2012-08-15

    This paper discusses the bio-inspired synthesis of type YFeAl ferrites encapsulated into polyglycerol dendrimers (PGLD) generation 3. The structure and morphological properties of the system YFeAl/PGLD was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The magnetic properties were studied through the techniques of Moessbauer spectroscopy and magnetization. The cytotoxicity of the nanoparticles encapsulated in dendrimers PGLD G3 at the cell membrane was studied against mammalian cell line CHO.K1 measuring the amount of lactate dehydrogenase (LDH) released by the cell damage. Microscopy TEM and XRD analysis indicate that spherical nanoparticles were obtained highly crystalline and monodisperse with size 20 nm

  9. A survey on bio inspired meta heuristic based clustering protocols for wireless sensor networks

    Science.gov (United States)

    Datta, A.; Nandakumar, S.

    2017-11-01

    Recent studies have shown that utilizing a mobile sink to harvest and carry data from a Wireless Sensor Network (WSN) can improve network operational efficiency as well as maintain uniform energy consumption by the sensor nodes in the network. Due to Sink mobility, the path between two sensor nodes continuously changes and this has a profound effect on the operational longevity of the network and a need arises for a protocol which utilizes minimal resources in maintaining routes between the mobile sink and the sensor nodes. Swarm Intelligence based techniques inspired by the foraging behavior of ants, termites and honey bees can be artificially simulated and utilized to solve real wireless network problems. The author presents a brief survey on various bio inspired swarm intelligence based protocols used in routing data in wireless sensor networks while outlining their general principle and operation.

  10. Hydrogels from Amorphous Calcium Carbonate and Polyacrylic Acid: Bio-Inspired Materials for "Mineral Plastics".

    Science.gov (United States)

    Sun, Shengtong; Mao, Li-Bo; Lei, Zhouyue; Yu, Shu-Hong; Cölfen, Helmut

    2016-09-19

    Given increasing environmental issues due to the large usage of non-biodegradable plastics based on petroleum, new plastic materials, which are economic, environmentally friendly, and recyclable are in high demand. One feasible strategy is the bio-inspired synthesis of mineral-based hybrid materials. Herein we report a facile route for an amorphous CaCO3 (ACC)-based hydrogel consisting of very small ACC nanoparticles physically cross-linked by poly(acrylic acid). The hydrogel is shapeable, stretchable, and self-healable. Upon drying, the hydrogel forms free-standing, rigid, and transparent objects with remarkable mechanical performance. By swelling in water, the material can completely recover the initial hydrogel state. As a matrix, thermochromism can also be easily introduced. The present hybrid hydrogel may represent a new class of plastic materials, the "mineral plastics". © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Dynamic analysis of a bio-inspired climbing robot using ADAMS-Simulink co-simulation

    Science.gov (United States)

    Chattopadhyay, P.; Dikshit, H.; Majumder, A.; Ghoshal, S.; Maity, A.

    2018-04-01

    Climbing robot has been an area of interest since the demand of inspection of pipeline, nuclear power plant, and various big structure is growing up rapidly. This paper represents the development of a bio-inspired modular robot which mimics inchworm locomotion during climbing. In the present paper, the climbing motion is achieved only on a flat vertical plane by magnetic adhesion principle. The robot is modelled as a 4-link planar mechanism with three revolute joints actuated by DC servo motors. Sinusoidal gait pattern is used to approximate the motion of an inchworm. The dynamics of the robot is presented by using ADAMS/MATLAB co-simulation methodology. The simulation result gives the maximum value of joint torque during one complete cycle of motion. This torque value is used for the selection of servo motor specifications required to build the prototype.

  12. A bio-inspired approach for the reduction of left ventricular workload.

    Directory of Open Access Journals (Sweden)

    Niema M Pahlevan

    Full Text Available Previous studies have demonstrated the existence of optimization criteria in the design and development of mammalians cardiovascular systems. Similarities in mammalian arterial wave reflection suggest there are certain design criteria for the optimization of arterial wave dynamics. Inspired by these natural optimization criteria, we investigated the feasibility of optimizing the aortic waves by modifying wave reflection sites. A hydraulic model that has physical and dynamical properties similar to a human aorta and left ventricle was used for a series of in-vitro experiments. The results indicate that placing an artificial reflection site (a ring at a specific location along the aorta may create a constructive wave dynamic that could reduce LV pulsatile workload. This simple bio-inspired approach may have important implications for the future of treatment strategies for diseased aorta.

  13. Tunable band gaps in bio-inspired periodic composites with nacre-like microstructure

    Science.gov (United States)

    Chen, Yanyu; Wang, Lifeng

    2014-08-01

    Periodic composite materials have many promising applications due to their unique ability to control the propagation of waves. Here, we report the existence and frequency tunability of complete elastic wave band gaps in bio-inspired periodic composites with nacre-like, brick-and-mortar microstructure. Numerical results show that complete band gaps in these periodic composites derive from local resonances or Bragg scattering, depending on the lattice angle and the volume fraction of each phase in the composites. The investigation of elastic wave propagation in finite periodic composites validates the simulated complete band gaps and further reveals the mechanisms leading to complete band gaps. Moreover, our results indicate that the topological arrangement of the mineral platelets and changes of material properties can be utilized to tune the evolution of complete band gaps. Our finding provides new opportunities to design mechanically robust periodic composite materials for wave absorption under hostile environments, such as for deep water applications.

  14. Fusion of nacre, mussel, and lotus leaf: bio-inspired graphene composite paper with multifunctional integration.

    Science.gov (United States)

    Zhong, Da; Yang, Qinglin; Guo, Lin; Dou, Shixue; Liu, Kesong; Jiang, Lei

    2013-07-07

    Multifunctional integration is an inherent characteristic for biological materials with multiscale structures. Learning from nature is an effective approach for scientists and engineers to construct multifunctional materials. In nature, mollusks (abalone), mussels, and the lotus have evolved different and optimized solutions to survive. Here, bio-inspired multifunctional graphene composite paper was fabricated in situ through the fusion of the different biological solutions from nacre (brick-and-mortar structure), mussel adhesive protein (adhesive property and reducing character), and the lotus leaf (self-cleaning effect). Owing to the special properties (self-polymerization, reduction, and adhesion), dopamine could be simultaneously used as a reducing agent for graphene oxide and as an adhesive, similar to the mortar in nacre, to crosslink the adjacent graphene. The resultant nacre-like graphene paper exhibited stable superhydrophobicity, self-cleaning, anti-corrosion, and remarkable mechanical properties underwater.

  15. Catalytic Water Oxidation by a Bio-inspired Nickel Complex with Redox Active Ligand

    Science.gov (United States)

    Wang, Dong; Bruner, Charlie O.

    2017-01-01

    The oxidation of water to dioxygen is important in natural photosynthesis. One of nature’s strategies for managing such multi-electron transfer reactions is to employ redox active metal-organic cofactor arrays. One prototype example is the copper-tyrosinate active site found in galactose oxidase. In this work, we have implemented such a strategy to develop a bio-inspired nickel-phenolate complex capable of catalyzing the oxidation of water to O2 electrochemically at neutral pH with a modest overpotential. The employment of the redox-active ligand turned out to be a useful strategy to avoid the formation of high-valent nickel intermediates while a reasonable turnover rate (0.15 s−1) is retained. PMID:29099176

  16. Catalytic Water Oxidation by a Bio-inspired Nickel Complex with a Redox-Active Ligand.

    Science.gov (United States)

    Wang, Dong; Bruner, Charlie O

    2017-11-20

    The oxidation of water (H 2 O) to dioxygen (O 2 ) is important in natural photosynthesis. One of nature's strategies for managing such multi-electron transfer reactions is to employ redox-active metal-organic cofactor arrays. One prototype example is the copper tyrosinate active site found in galactose oxidase. In this work, we have implemented such a strategy to develop a bio-inspired nickel phenolate complex capable of catalyzing the oxidation of H 2 O to O 2 electrochemically at neutral pH with a modest overpotential. Employment of the redox-active ligand turned out to be a useful strategy to avoid the formation of high-valent nickel intermediates while a reasonable turnover rate (0.15 s -1 ) is retained.

  17. Image sensor system with bio-inspired efficient coding and adaptation.

    Science.gov (United States)

    Okuno, Hirotsugu; Yagi, Tetsuya

    2012-08-01

    We designed and implemented an image sensor system equipped with three bio-inspired coding and adaptation strategies: logarithmic transform, local average subtraction, and feedback gain control. The system comprises a field-programmable gate array (FPGA), a resistive network, and active pixel sensors (APS), whose light intensity-voltage characteristics are controllable. The system employs multiple time-varying reset voltage signals for APS in order to realize multiple logarithmic intensity-voltage characteristics, which are controlled so that the entropy of the output image is maximized. The system also employs local average subtraction and gain control in order to obtain images with an appropriate contrast. The local average is calculated by the resistive network instantaneously. The designed system was successfully used to obtain appropriate images of objects that were subjected to large changes in illumination.

  18. A Bio-inspired Approach for Power and Performance Aware Resource Allocation in Clouds

    Directory of Open Access Journals (Sweden)

    Kumar Rajesh

    2016-01-01

    Full Text Available In order to cope with increasing demand, cloud market players such as Amazon, Microsoft, Google, Gogrid, Flexiant, etc. have set up large sized data centers. Due to monotonically increasing size of data centers and heterogeneity of resources have made resource allocation a challenging task. A large percentage of total energy consumption of the data centers gets wasted because of under-utilization of resources. Thus, there is a need of resource allocation technique that improves the utilization of resources with effecting performance of services being delivered to end users. In this work, a bio-inspired resource allocation approach is proposed with the aim to improve utilization and hence the energy efficiency of the cloud infrastructure. The proposed approach makes use of Cuckoo search for power and performance aware allocation of resources to the services hired by the end users. The proposed approach is implemented in CloudSim. The simulation results have shown approximately 12% saving in energy consumption.

  19. Microneedle, bio-microneedle and bio-inspired microneedle: A review.

    Science.gov (United States)

    Ma, Guojun; Wu, Chengwei

    2017-04-10

    Microneedles (MNs) are micro-scale needles used for drug delivery and other targets. Micro-scale size endows them with many advantages over hypodermic needles, including painlessness, minimal invasiveness and convenient operation, but it may also lead to risk of mechanical failures, which should be prevented in the clinical applications of MNs. The objective of this review is mainly to introduce studies on the mechanics problems with respect to MNs. Firstly, the basic knowledge of MNs is introduced in brief, so that readers can understand the basic characteristics of MNs. Secondly, researches on inserting behavior and mechanical performances of MNs are discussed. Thirdly, literatures on the drug delivery and the pain resulted from the insertion of MNs are overviewed. Finally, some bio-microneedles and bio-inspired MNs are introduced. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Role of cellulose functionality in bio-inspired synthesis of nano bioactive glass.

    Science.gov (United States)

    Gupta, Nidhi; Santhiya, Deenan

    2017-06-01

    In search of abundant cheaper natural polymer for bio-inspired bioactive glass nanoparticles synthesis, cellulose and its derivatives have been considered as a template. Different templates explored in the present studies are pure cellulose, methyl cellulose and amine grafted cellulose. To the best of our knowledge, for the first time of the considered templates, pure cellulose and amine grafted cellulose results in in situ nano particulate composite formation while interestingly methyl cellulose proves to be an excellent sacrificial template for the synthesis of uniform bioglass nanoparticles of diameter in the range of 55nm. Further, viscoelastic measurements were carried out using dynamic mechanical analyzer. Herein, an attempt has been made to establish structure-mechanical relationship based on the templates. Moreover, in vitro bioactivity is also observed to be affected by the nature of the template molecule used for the synthesis of bioactive glass. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. A Bio-Inspired Approach to Alarm Malware Attacks in Mobile Handsets

    Science.gov (United States)

    Ahn, Taejin; Park, Taejoon

    With proliferation of smart handsets capable of mobile Internet, the severity of malware attacks targeting such handsets is rapidly increasing, thereby requiring effective countermeasure for them. However, existing signature-based solutions are not suitable for resource-poor handsets due to the excessive run-time overhead of matching against ever-increasing malware pattern database as well as the limitation of detecting well-known malware only. To overcome these drawbacks, we present a bio-inspired approach to discriminate malware (non-self) from normal programs (self) by replicating the processes of biological immune system. Our proposed approach achieves superior performance in terms of detecting 83.7% of new malware or their variants and scalable storage requirement that grows very slowly with inclusion of new malware, making it attractive for use with mobile handsets.

  2. Fusion of nacre, mussel, and lotus leaf: bio-inspired graphene composite paper with multifunctional integration

    Science.gov (United States)

    Zhong, Da; Yang, Qinglin; Guo, Lin; Dou, Shixue; Liu, Kesong; Jiang, Lei

    2013-06-01

    Multifunctional integration is an inherent characteristic for biological materials with multiscale structures. Learning from nature is an effective approach for scientists and engineers to construct multifunctional materials. In nature, mollusks (abalone), mussels, and the lotus have evolved different and optimized solutions to survive. Here, bio-inspired multifunctional graphene composite paper was fabricated in situ through the fusion of the different biological solutions from nacre (brick-and-mortar structure), mussel adhesive protein (adhesive property and reducing character), and the lotus leaf (self-cleaning effect). Owing to the special properties (self-polymerization, reduction, and adhesion), dopamine could be simultaneously used as a reducing agent for graphene oxide and as an adhesive, similar to the mortar in nacre, to crosslink the adjacent graphene. The resultant nacre-like graphene paper exhibited stable superhydrophobicity, self-cleaning, anti-corrosion, and remarkable mechanical properties underwater.Multifunctional integration is an inherent characteristic for biological materials with multiscale structures. Learning from nature is an effective approach for scientists and engineers to construct multifunctional materials. In nature, mollusks (abalone), mussels, and the lotus have evolved different and optimized solutions to survive. Here, bio-inspired multifunctional graphene composite paper was fabricated in situ through the fusion of the different biological solutions from nacre (brick-and-mortar structure), mussel adhesive protein (adhesive property and reducing character), and the lotus leaf (self-cleaning effect). Owing to the special properties (self-polymerization, reduction, and adhesion), dopamine could be simultaneously used as a reducing agent for graphene oxide and as an adhesive, similar to the mortar in nacre, to crosslink the adjacent graphene. The resultant nacre-like graphene paper exhibited stable superhydrophobicity, self

  3. A bio-inspired glucose controller based on pancreatic β-cell physiology.

    Science.gov (United States)

    Herrero, Pau; Georgiou, Pantelis; Oliver, Nick; Johnston, Desmond G; Toumazou, Christofer

    2012-05-01

    Control algorithms for closed-loop insulin delivery in type 1 diabetes have been mainly based on control engineering or artificial intelligence techniques. These, however, are not based on the physiology of the pancreas but seek to implement engineering solutions to biology. Developments in mathematical models of the β-cell physiology of the pancreas have described the glucose-induced insulin release from pancreatic β cells at a molecular level. This has facilitated development of a new class of bio-inspired glucose control algorithms that replicate the functionality of the biological pancreas. However, technologies for sensing glucose levels and delivering insulin use the subcutaneous route, which is nonphysiological and introduces some challenges. In this article, a novel glucose controller is presented as part of a bio-inspired artificial pancreas. A mathematical model of β-cell physiology was used as the core of the proposed controller. In order to deal with delays and lack of accuracy introduced by the subcutaneous route, insulin feedback and a gain scheduling strategy were employed. A United States Food and Drug Administration-accepted type 1 diabetes mellitus virtual population was used to validate the presented controller. Premeal and postmeal mean ± standard deviation blood glucose levels for the adult and adolescent populations were well within the target range set for the controller [(70, 180) mg/dl], with a percent time in range of 92.8 ± 7.3% for the adults and 83.5 ± 14% for the adolescents. This article shows for the first time very good glucose control in a virtual population with type 1 diabetes mellitus using a controller based on a subcellular β-cell model. © 2012 Diabetes Technology Society.

  4. Direct numerical simulations of drag reduction in turbulent channel flow over bio-inspired herringbone riblet-texture

    NARCIS (Netherlands)

    Benschop, H.O.G.; Westerweel, J.; Breugem, W.P.

    2015-01-01

    The use of drag reducing surface textures is a promising passive method to reduce fuel consumption. Probably most wellknown is the utilisation of shark-skin inspired ridges or riblets parallel to the mean flow. They can reduce drag up to 10%. Recently another bio-inspired texture based on bird

  5. Bio-inspired iron and manganese complexes derived from mixed N,O ligands for the oxidation of olefins

    NARCIS (Netherlands)

    Moelands, M.A.H.

    2014-01-01

    This Thesis describes the synthesis and structural analysis of bio-inspired iron and manganese complexes used for the catalytic oxidation of olefin substrates. The development of catalytic systems for oxidation chemistry that are based on first row transition metals and that apply a green oxidant

  6. Bio-inspired nano-photodiode for Low Light, High Resolution and crosstalk-free CMOS image sensing

    KAUST Repository

    Saffih, Faycal; Fitzpatrick, Nathaniel N.; Mohammad, Mohammad Ali; Evoy, S.; Cui, Bo

    2011-01-01

    photodiode morphology. The proposed bio-inspired nanorod photodiode puts the depletion region length on the path of the incident photon instead of on its width, as the case is with the planar photodiodes. The depletion region has a revolving volume

  7. Application of quercetin and its bio-inspired nanoparticles as anti-adhesive agents against Bacillus subtilis attachment to surface

    Energy Technology Data Exchange (ETDEWEB)

    Raie, Diana S., E-mail: raiediana@yahoo.com [Process Design and Development Department, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt); Mhatre, Eisha [Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena (FSU), Jena (Germany); Thiele, Matthias [Nanobiophotonic Department, Leibniz Institute of Photonic Technology Jena (IPHT), Jena (Germany); Labena, A. [Process Design and Development Department, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt); El-Ghannam, Gamal [National Institute of Laser Enhanced Sciences (NILES), Cairo University, Giza (Egypt); Farahat, Laila A. [Process Design and Development Department, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt); Youssef, Tareq [National Institute of Laser Enhanced Sciences (NILES), Cairo University, Giza (Egypt); Fritzsche, Wolfgang [Nanobiophotonic Department, Leibniz Institute of Photonic Technology Jena (IPHT), Jena (Germany); Kovács, Ákos T., E-mail: akos-tibor.kovacs@uni-jena.de [Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena (FSU), Jena (Germany)

    2017-01-01

    The aim of this study was directed to reveal the repulsive effect of coated glass slides by quercetin and its bio-inspired titanium oxide and tungsten oxide nanoparticles on physical surface attachment of Bacillus subtilis as an ab-initio step of biofilm formation. Nanoparticles were successfully synthesized using sol–gel and acid precipitation methods for titanium oxide and tungsten oxide, respectively (in the absence or presence of quercetin). The anti-adhesive impact of the coated-slides was tested through the physical attachment of B. subtilis after 24 h using Confocal Laser Scanning Microscopy (CLSM). Here, quercetin was presented as a bio-route for the synthesis of tungsten mixed oxides nano-plates at room temperature. In addition, quercetin had an impact on zeta potential and adsorption capacity of both bio-inspired amorphous titanium oxide and tungsten oxide nano-plates. Interestingly, our experiments indicated a contrary effect of quercetin as an anti-adhesive agent than previously reported. However, its bio-inspired metal oxide proved their repulsive efficiency. In addition, quercetin-mediated nano-tungsten and quercetin-mediated amorphous titanium showed anti-adhesive activity against B. subtilis biofilm. - Highlights: • Novel quercetin-mediated nanoparticles were tested for anti-adhesion against attachment of cells forming biofilms. • Quercetin showed a low-grade of protection level against bacterial attachment. • Bio-inspired nano-anatase showed a lower efficiency than amorphous titanium. • Thermally treated bio-inspired nano-tungsten gets an improved anti-adhesive activity.

  8. Bio-inspired particle separator design based on the food retention mechanism by suspension-feeding fish

    International Nuclear Information System (INIS)

    Hung, Tien-Chieh; Piedrahita, Raul H; Cheer, Angela

    2012-01-01

    A new particle separator is designed using a crossflow filtration mechanism inspired by suspension-feeding fish in this study. To construct the model of the bio-inspired particle separator, computational fluid dynamics techniques are used, and parameters related to separator shape, fluid flow and particle properties that might affect the performance in removing particles from the flow, are varied and tested. The goal is to induce a flow rotation which enhances the separation of particles from the flow, reduce the particle-laden flow that exits via a collection zone at the lower/posterior end of the separator, while at the same time increase the concentration of particles in that flow. Based on preliminary particle removal efficiency tests, an exiting flow through the collection zone of about 8% of the influent flow rate is selected for all the performance tests of the separator including trials with particles carried by air flow instead of water. Under this condition, the simulation results yield similar particle removal efficiencies in water and air but with different particle properties. Particle removal efficiencies (percentage of influent particles that exit through the collection zone) were determined for particles ranging in size from 1 to 1500 µm with a density between 1000 and 1150 kg m −3 in water and 2 and 19 mm and 68 and 2150 kg m −3 in air. As an example, removal efficiencies are 66% and 64% for 707 µm diameter particles with a density of 1040 kg m −3 in water and for 2 mm particles with a density of 68 kg m −3 in air, respectively. No significant performance difference is found by geometrically scaling the inlet diameter of the separator up or down in the range from 2.5 to 10 cm. (paper)

  9. Design of a bio-inspired pneumatic artificial muscle with self-contained sensing.

    Science.gov (United States)

    Erin, Onder; Pol, Nishant; Valle, Luis; Yong-Lae Park

    2016-08-01

    Pneumatic artificial muscles (PAMs) are one of the most famous linear actuators in bio-inspired robotics. They can generate relatively high linear force considering their form factors and weights. Furthermore, PAMs are inexpensive compared with traditional electromagnetic actuators (e.g. DC motors) and also inherently light and compliant. In robotics applications, however, they typically require external sensing mechanisms due to their nonlinear behaviors, which may make the entire mechanical system bulky and complicated, limiting their use in simple systems. This study presents the design and fabrication of a low-cost McKibben-type PAM with a self-contained displacement and force sensing capability that does not require any external sensing elements. The proposed PAM can detect axial contraction force and displacement at the same time. In this study, the design of a traditional McKibben muscle was modified to include an inductive coil surrounding the muscle fibers. Then, a thin, soft silicone layer was coated outside of the muscle to protect and hold the sensing coil on the actuator. This novel design measures coil inductance change to determine the contraction force and the displacement. The process can be applied to a variety of existing McKibben actuator designs without significantly changing the rigidity of the actuator while minimizing the device's footprint.

  10. Bio-inspired multistructured conical copper wires for highly efficient liquid manipulation.

    Science.gov (United States)

    Wang, Qianbin; Meng, Qingan; Chen, Ming; Liu, Huan; Jiang, Lei

    2014-09-23

    Animal hairs are typical structured conical fibers ubiquitous in natural system that enable the manipulation of low viscosity liquid in a well-controlled manner, which serves as the fundamental structure in Chinese brush for ink delivery in a controllable manner. Here, drawing inspiration from these structure, we developed a dynamic electrochemical method that enables fabricating the anisotropic multiscale structured conical copper wire (SCCW) with controllable conicity and surface morphology. The as-prepared SCCW exhibits a unique ability for manipulating liquid with significantly high efficiency, and over 428 times greater than its own volume of liquid could be therefore operated. We propose that the boundary condition of the dynamic liquid balance behavior on conical fibers, namely, steady holding of liquid droplet at the tip region of the SCCW, makes it an excellent fibrous medium to manipulate liquid. Moreover, we demonstrate that the titling angle of the SCCW can also affect its efficiency of liquid manipulation by virtue of its mechanical rigidity, which is hardly realized by flexible natural hairs. We envision that the bio-inspired SCCW could give inspiration in designing materials and devices to manipulate liquid in a more controllable way and with high efficiency.

  11. Bio-inspired online variable recruitment control of fluidic artificial muscles

    Science.gov (United States)

    Jenkins, Tyler E.; Chapman, Edward M.; Bryant, Matthew

    2016-12-01

    This paper details the creation of a hybrid variable recruitment control scheme for fluidic artificial muscle (FAM) actuators with an emphasis on maximizing system efficiency and switching control performance. Variable recruitment is the process of altering a system’s active number of actuators, allowing operation in distinct force regimes. Previously, FAM variable recruitment was only quantified with offline, manual valve switching; this study addresses the creation and characterization of novel, on-line FAM switching control algorithms. The bio-inspired algorithms are implemented in conjunction with a PID and model-based controller, and applied to a simulated plant model. Variable recruitment transition effects and chatter rejection are explored via a sensitivity analysis, allowing a system designer to weigh tradeoffs in actuator modeling, algorithm choice, and necessary hardware. Variable recruitment is further developed through simulation of a robotic arm tracking a variety of spline position inputs, requiring several levels of actuator recruitment. Switching controller performance is quantified and compared with baseline systems lacking variable recruitment. The work extends current variable recruitment knowledge by creating novel online variable recruitment control schemes, and exploring how online actuator recruitment affects system efficiency and control performance. Key topics associated with implementing a variable recruitment scheme, including the effects of modeling inaccuracies, hardware considerations, and switching transition concerns are also addressed.

  12. Morphological self stabilization of locomotion gaits: illustration on a few examples from bio-inspired locomotion.

    Science.gov (United States)

    Chevallereau, Christine; Boyer, Frédéric; Porez, Mathieu; Mauny, Johan; Aoustin, Yannick

    2017-06-20

    To a large extent, robotics locomotion can be viewed as cyclic motions, named gaits. Due to the high complexity of the locomotion dynamics, to find the control laws that ensure an expected gait and its stability with respect to external perturbations, is a challenging issue for feedback control. To address this issue, a promising way is to take inspiration from animals that intensively exploit the interactions of the passive degrees of freedom of their body with their physical surroundings, to outsource the high-level exteroceptive feedback control to low-level proprioceptive ones. In this case, passive interactions can ensure most of the expected control goals. In this article, we propose a methodological framework to study the role of morphology in the design of locomotion gaits and their stability. This framework ranges from modelling to control aspects, and is illustrated through three examples from bio-inspired locomotion: a three-dimensional micro air vehicle in hovering flight, a pendular planar climber and a bipedal planar walker. In these three cases, we will see how simple considerations based on the morphology of the body can ensure the existence of passive stable gaits without requiring any high-level control.

  13. Natural and bio-inspired underwater adhesives: Current progress and new perspectives

    Science.gov (United States)

    Cui, Mengkui; Ren, Susu; Wei, Shicao; Sun, Chengjun; Zhong, Chao

    2017-11-01

    Many marine organisms harness diverse protein molecules as underwater adhesives to achieve strong and robust interfacial adhesion under dynamic and turbulent environments. Natural underwater adhesion phenomena thus provide inspiration for engineering adhesive materials that can perform in water or high-moisture settings for biomedical and industrial applications. Here we review examples of biological adhesives to show the molecular features of natural adhesives and discuss how such knowledge serves as a heuristic guideline for the rational design of biologically inspired underwater adhesives. In view of future bio-inspired research, we propose several potential opportunities, either in improving upon current L-3, 4-dihydroxyphenylalanine-based and coacervates-enabled adhesives with new features or engineering conceptually new types of adhesives that recapitulate important characteristics of biological adhesives. We underline the importance of viewing natural adhesives as dynamic materials, which owe their outstanding performance to the cellular coordination of protein expression, delivery, deposition, assembly, and curing of corresponding components with spatiotemporal control. We envision that the emerging synthetic biology techniques will provide great opportunities for advancing both fundamental and application aspects of underwater adhesives.

  14. Vibro-Perception of Optical Bio-Inspired Fiber-Skin.

    Science.gov (United States)

    Li, Tao; Zhang, Sheng; Lu, Guo-Wei; Sunami, Yuta

    2018-05-12

    In this research, based on the principle of optical interferometry, the Mach-Zehnder and Optical Phase-locked Loop (OPLL) vibro-perception systems of bio-inspired fiber-skin are designed to mimic the tactile perception of human skin. The fiber-skin is made of the optical fiber embedded in the silicone elastomer. The optical fiber is an instinctive and alternative sensor for tactile perception with high sensitivity and reliability, also low cost and susceptibility to the magnetic interference. The silicone elastomer serves as a substrate with high flexibility and biocompatibility, and the optical fiber core serves as the vibro-perception sensor to detect physical motions like tapping and sliding. According to the experimental results, the designed optical fiber-skin demonstrates the ability to detect the physical motions like tapping and sliding in both the Mach-Zehnder and OPLL vibro-perception systems. For direct contact condition, the OPLL vibro-perception system shows better performance compared with the Mach-Zehnder vibro-perception system. However, the Mach-Zehnder vibro-perception system is preferable to the OPLL system in the indirect contact experiment. In summary, the fiber-skin is validated to have light touch character and excellent repeatability, which is highly-suitable for skin-mimic sensing.

  15. A Wireless Fatigue Monitoring System Utilizing a Bio-Inspired Tree Ring Data Tracking Technique

    Directory of Open Access Journals (Sweden)

    Shi Bai

    2014-03-01

    Full Text Available Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is proposed. The general framework, methodology, and verification of this intelligent system are discussed in details. The rain-flow counting (RFC method is adopted as the core algorithm which quantifies fatigue damages, and Digital Signal Processing (DSP is introduced as the core module for data collection and analysis. Laboratory test results based on strain gauges and polyvinylidene fluoride (PVDF sensors have shown that the developed intelligent system can provide a reliable quick feedback and early warning of fatigue failure. With the merits of low cost, high accuracy and great reliability, the developed wireless fatigue sensing system can be further applied to mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, etc.

  16. Mechanical properties of a bio-inspired robotic knifefish with an undulatory propulsor

    International Nuclear Information System (INIS)

    Curet, Oscar M; Patankar, Neelesh A; MacIver, Malcolm A; Lauder, George V

    2011-01-01

    South American electric knifefish are a leading model system within neurobiology. Recent efforts have focused on understanding their biomechanics and relating this to their neural processing strategies. Knifefish swim by means of an undulatory fin that runs most of the length of their body, affixed to the belly. Propelling themselves with this fin enables them to keep their body relatively straight while swimming, enabling straightforward robotic implementation with a rigid hull. In this study, we examined the basic properties of undulatory swimming through use of a robot that was similar in some key respects to the knifefish. As we varied critical fin kinematic variables such as frequency, amplitude, and wavelength of sinusoidal traveling waves, we measured the force generated by the robot when it swam against a stationary sensor, and its velocity while swimming freely within a flow tunnel system. Our results show that there is an optimal operational region in the fin's kinematic parameter space. The optimal actuation parameters found for the robotic knifefish are similar to previously observed parameters for the black ghost knifefish, Apteronotus albifrons. Finally, we used our experimental results to show how the force generated by the robotic fin can be decomposed into thrust and drag terms. Our findings are useful for future bio-inspired underwater vehicles as well as for understanding the mechanics of knifefish swimming.

  17. Bio-Inspired Supramolecular Chemistry Provides Highly Concentrated Dispersions of Carbon Nanotubes in Polythiophene

    Directory of Open Access Journals (Sweden)

    Yen-Ting Lin

    2016-06-01

    Full Text Available In this paper we report the first observation, through X-ray diffraction, of noncovalent uracil–uracil (U–U dimeric π-stacking interactions in carbon nanotube (CNT–based supramolecular assemblies. The directionally oriented morphology determined using atomic force microscopy revealed highly organized behavior through π-stacking of U moieties in a U-functionalized CNT derivative (CNT–U. We developed a dispersion system to investigate the bio-inspired interactions between an adenine (A-terminated poly(3-adeninehexyl thiophene (PAT and CNT–U. These hybrid CNT–U/PAT materials interacted through π-stacking and multiple hydrogen bonding between the U moieties of CNT–U and the A moieties of PAT. Most importantly, the U···A multiple hydrogen bonding interactions between CNT–U and PAT enhanced the dispersion of CNT–U in a high-polarity solvent (DMSO. The morphology of these hybrids, determined using transmission electron microscopy, featured grape-like PAT bundles wrapped around the CNT–U surface; this tight connection was responsible for the enhanced dispersion of CNT–U in DMSO.

  18. Data-Foraging-Oriented Reconnaissance Based on Bio-Inspired Indirect Communication for Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Josué Castañeda Cisneros

    2017-07-01

    Full Text Available In recent years, aerial vehicles have allowed exploring scenarios with harsh conditions. These can conduct reconnaissance tasks in areas that change periodically and have a high spatial and temporal resolution. The objective of a reconnaissance task is to survey an area and retrieve strategic information. The aerial vehicles, however, have inherent constraints in terms of energy and transmission range due to their mobility. Despite these constraints, the Data Foraging problem requires the aerial vehicles to exchange information about profitable data sources. In Data Foraging, establishing a single path is not viable because of dynamic conditions of the environment. Thus, reconnaissance must be focused on periodically searching profitable environmental data sources, as some animals perform foraging. In this work, a data-foraging-oriented reconnaissance algorithm based on bio-inspired indirect communication for aerial vehicles is presented. The approach establishes several paths that overlap to identify valuable data sources. Inspired by the stigmergy principle, the aerial vehicles indirectly communicate through artificial pheromones. The aerial vehicles traverse the environment using a heuristic algorithm that uses the artificial pheromones as feedback. The solution is formally defined and mathematically evaluated. In addition, we show the viability of the algorithm by simulations which have been tested through various statistical hypothesis.

  19. A compact bio-inspired visible/NIR imager for image-guided surgery (Conference Presentation)

    Science.gov (United States)

    Gao, Shengkui; Garcia, Missael; Edmiston, Chris; York, Timothy; Marinov, Radoslav; Mondal, Suman B.; Zhu, Nan; Sudlow, Gail P.; Akers, Walter J.; Margenthaler, Julie A.; Liang, Rongguang; Pepino, Marta; Achilefu, Samuel; Gruev, Viktor

    2016-03-01

    Inspired by the visual system of the morpho butterfly, we have designed, fabricated, tested and clinically translated an ultra-sensitive, light weight and compact imaging sensor capable of simultaneously capturing near infrared (NIR) and visible spectrum information. The visual system of the morpho butterfly combines photosensitive cells with spectral filters at the receptor level. The spectral filters are realized by alternating layers of high and low dielectric constant, such as air and cytoplasm. We have successfully mimicked this concept by integrating pixelated spectral filters, realized by alternating silicon dioxide and silicon nitrate layers, with an array of CCD detectors. There are four different types of pixelated spectral filters in the imaging plane: red, green, blue and NIR. The high optical density (OD) of all spectral filters (OD>4) allow for efficient rejections of photons from unwanted bands. The single imaging chip weighs 20 grams with form factor of 5mm by 5mm. The imaging camera is integrated with a goggle display system. A tumor targeted agent, LS301, is used to identify all spontaneous tumors in a transgenic PyMT murine model of breast cancer. The imaging system achieved sensitivity of 98% and selectivity of 95%. We also used our imaging sensor to locate sentinel lymph nodes (SLNs) in patients with breast cancer using indocyanine green tracer. The surgeon was able to identify 100% of SLNs when using our bio-inspired imaging system, compared to 93% when using information from the lymphotropic dye and 96% when using information from the radioactive tracer.

  20. Bio-inspired composites with functionally graded platelets exhibit enhanced stiffness.

    Science.gov (United States)

    Tapse, Sanjay; S, Anup

    2017-11-09

    Unidirectional composites inspired from biological materials such as nacre, are composed of stiff platelets arranged in a staggered manner within a soft matrix. Elaborate analyses have been conducted on the aforementioned composites and they are found to have excellent mechanical properties like stiffness, strength and fracture toughness. The superior properties exhibited by these composites have been proved to be the result of its unique structure. An emerging development in the field of composite structures is Functionally Graded Composites(FGC), whose properties vary spatially and possess enhanced thermo-mechanical properties. In this paper, the platelets are functionally graded with its Young's Modulus varying parabolically along the length. Two different models - namely, Tension Shear Chain Model and Minimisation of Complementary Energy Model have been employed to obtain the stiffness of the overall composite analytically. The effect of various parameters that define the composite model such as overlapping length between any two neighbouring platelets, different gradation parameters and platelet aspect ratio on the overall mechanical properties have been studied. Composites with functionally graded platelets are found to possess enhanced stiffness (upto 14% higher) for certain values of these parameters. The obtained solutions have been validated using Finite Element Analysis. Bio-inspired composites with functionally graded platelets can be engineered for structural applications, such as in automobile, aerospace and aircraft industry, where stiffness plays a crucial role. © 2017 IOP Publishing Ltd.

  1. Natural and bio-inspired underwater adhesives: Current progress and new perspectives

    Directory of Open Access Journals (Sweden)

    Mengkui Cui

    2017-11-01

    Full Text Available Many marine organisms harness diverse protein molecules as underwater adhesives to achieve strong and robust interfacial adhesion under dynamic and turbulent environments. Natural underwater adhesion phenomena thus provide inspiration for engineering adhesive materials that can perform in water or high-moisture settings for biomedical and industrial applications. Here we review examples of biological adhesives to show the molecular features of natural adhesives and discuss how such knowledge serves as a heuristic guideline for the rational design of biologically inspired underwater adhesives. In view of future bio-inspired research, we propose several potential opportunities, either in improving upon current L-3, 4-dihydroxyphenylalanine-based and coacervates-enabled adhesives with new features or engineering conceptually new types of adhesives that recapitulate important characteristics of biological adhesives. We underline the importance of viewing natural adhesives as dynamic materials, which owe their outstanding performance to the cellular coordination of protein expression, delivery, deposition, assembly, and curing of corresponding components with spatiotemporal control. We envision that the emerging synthetic biology techniques will provide great opportunities for advancing both fundamental and application aspects of underwater adhesives.

  2. Atomistic simulation on the plastic deformation and fracture of bio-inspired graphene/Ni nanocomposites

    Science.gov (United States)

    Yang, Zhenyu; Wang, Dandan; Lu, Zixing; Hu, Wenjun

    2016-11-01

    Molecular dynamics simulations were performed to investigate the plastic deformation and fracture behaviors of bio-inspired graphene/metal nanocomposites, which have a "brick-and-mortar" nanostructure, consisting of hard graphene single-layers embedded in a soft Ni matrix. The plastic deformation mechanisms of the nanocomposites were analyzed as well as their effects on the mechanical properties with various geometrical variations. It was found that the strength and ductility of the metal matrix can be highly enhanced with the addition of the staggered graphene layers, and the plastic deformation can be attributed to the interfacial sliding, dislocation nucleation, and cracks' combination. The strength of the nanocomposites strongly depends on the length scale of the nanostructure and the interlayer distance as well. In addition, slip at the interface releases the stress in graphene layers, leading to the stress distribution on the graphene more uniform. The present results are expected to contribute to the design of the nanolayered graphene/metal composites with high performance.

  3. Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Hu Bing-shan

    2010-02-01

    Full Text Available Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

  4. Research on one Bio-inspired Jumping Locomotion Robot for Search and Rescue

    Directory of Open Access Journals (Sweden)

    Dunwen Wei

    2014-10-01

    Full Text Available Jumping locomotion is much more effective than other locomotion means in order to tackle the unstructured and complex environment in research and rescue. Here, a bio-inspired jumping robot with a closed-chain mechanism is proposed to achieve the power amplification during taking-off. Through actuating one variable transmission mechanism to change the transmission ratio, the jumping robot reveals biological characteristics in the phase of posture adjustment when adjusting the height and distance of one jump. The kinematics and dynamics of the simplified jumping mechanism model in one jumping cycle sequence are analysed. A compliant contact model considering nonlinear damping is investigated for jumping performance under different terrain characteristics. The numerical simulation algorithm with regard to solving the dynamical equation is described and simulation results are discussed. Finally, one primary prototype and experiment are described. The experimental results show the distance of jumping in the horizontal direction increases with the increasing gear ratio, while the height of jumping decreases in reverse. The jumping robot can enhance the capability to adapt to unknown cluttered environments, such as those encountered in research and rescue, using this strategy.

  5. A Compact VLSI System for Bio-Inspired Visual Motion Estimation.

    Science.gov (United States)

    Shi, Cong; Luo, Gang

    2018-04-01

    This paper proposes a bio-inspired visual motion estimation algorithm based on motion energy, along with its compact very-large-scale integration (VLSI) architecture using low-cost embedded systems. The algorithm mimics motion perception functions of retina, V1, and MT neurons in a primate visual system. It involves operations of ternary edge extraction, spatiotemporal filtering, motion energy extraction, and velocity integration. Moreover, we propose the concept of confidence map to indicate the reliability of estimation results on each probing location. Our algorithm involves only additions and multiplications during runtime, which is suitable for low-cost hardware implementation. The proposed VLSI architecture employs multiple (frame, pixel, and operation) levels of pipeline and massively parallel processing arrays to boost the system performance. The array unit circuits are optimized to minimize hardware resource consumption. We have prototyped the proposed architecture on a low-cost field-programmable gate array platform (Zynq 7020) running at 53-MHz clock frequency. It achieved 30-frame/s real-time performance for velocity estimation on 160 × 120 probing locations. A comprehensive evaluation experiment showed that the estimated velocity by our prototype has relatively small errors (average endpoint error < 0.5 pixel and angular error < 10°) for most motion cases.

  6. Bio-inspired patterned networks (BIPS) for development of wearable/disposable biosensors

    Science.gov (United States)

    McLamore, E. S.; Convertino, M.; Hondred, John; Das, Suprem; Claussen, J. C.; Vanegas, D. C.; Gomes, C.

    2016-05-01

    Here we demonstrate a novel approach for fabricating point of care (POC) wearable electrochemical biosensors based on 3D patterning of bionanocomposite networks. To create Bio-Inspired Patterned network (BIPS) electrodes, we first generate fractal network in silico models that optimize transport of network fluxes according to an energy function. Network patterns are then inkjet printed onto flexible substrate using conductive graphene ink. We then deposit fractal nanometal structures onto the graphene to create a 3D nanocomposite network. Finally, we biofunctionalize the surface with biorecognition agents using covalent bonding. In this paper, BIPS are used to develop high efficiency, low cost biosensors for measuring glucose as a proof of concept. Our results on the fundamental performance of BIPS sensors show that the biomimetic nanostructures significantly enhance biosensor sensitivity, accuracy, response time, limit of detection, and hysteresis compared to conventional POC non fractal electrodes (serpentine, interdigitated, and screen printed electrodes). BIPs, in particular Apollonian patterned BIPS, represent a new generation of POC biosensors based on nanoscale and microscale fractal networks that significantly improve electrical connectivity, leading to enhanced sensor performance.

  7. A bio-inspired swarm robot coordination algorithm for multiple target searching

    Science.gov (United States)

    Meng, Yan; Gan, Jing; Desai, Sachi

    2008-04-01

    The coordination of a multi-robot system searching for multi targets is challenging under dynamic environment since the multi-robot system demands group coherence (agents need to have the incentive to work together faithfully) and group competence (agents need to know how to work together well). In our previous proposed bio-inspired coordination method, Local Interaction through Virtual Stigmergy (LIVS), one problem is the considerable randomness of the robot movement during coordination, which may lead to more power consumption and longer searching time. To address these issues, an adaptive LIVS (ALIVS) method is proposed in this paper, which not only considers the travel cost and target weight, but also predicting the target/robot ratio and potential robot redundancy with respect to the detected targets. Furthermore, a dynamic weight adjustment is also applied to improve the searching performance. This new method a truly distributed method where each robot makes its own decision based on its local sensing information and the information from its neighbors. Basically, each robot only communicates with its neighbors through a virtual stigmergy mechanism and makes its local movement decision based on a Particle Swarm Optimization (PSO) algorithm. The proposed ALIVS algorithm has been implemented on the embodied robot simulator, Player/Stage, in a searching target. The simulation results demonstrate the efficiency and robustness in a power-efficient manner with the real-world constraints.

  8. Fabrication of bio-inspired nitinol alloy surface with tunable anisotropic wetting and high adhesive ability.

    Science.gov (United States)

    Tian, Yan L; Zhao, Yue C; Yang, Cheng J; Wang, Fu J; Liu, Xian P; Jing, Xiu B

    2018-10-01

    In this paper, micro/nano-scale structures were fabricated on nitinol alloy (NiTi) to realize tunable anisotropic wetting and high adhesive capability. Laser texturing and silanization process are utilized to change the morphological and chemical properties of substrates. It is noted that these treated substrates exhibit the joint characteristics of anisotropic wetting and high adhesive capability. In order to investigate the influences of laser-texturing and silanization processes on NiTi, these surfaces were evaluated using scanning electron microscope (SEM), a white light confocal microscope, X-ray photoelectron spectroscopy (XPS) and goniometer. The relationship between water volume and anisotropic wetting was also established. From the experimental testing, we can obtain the following conclusions: (1) the anisotropic wetting characterized by the difference between the water contact angles (WCAs) in the vertical and parallel directions ranges from 0° to 20.3°, which is far more than the value of natural rice leaves. (2) the water sliding angles (WSAs) kept stable at 180°, successfully mimicking the adhesive ability of rose petals. (3) the silanization process could strengthen the hydrophobicity but weaken anisotropic wetting. These bio-inspired NiTi surfaces have a tremendous potential applications such as microfluidic devices, bio-mimetic materials fabrication and lab on chip. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Bio-inspired hydrophobic modification of cellulose nanocrystals with castor oil.

    Science.gov (United States)

    Shang, Qianqian; Liu, Chengguo; Hu, Yun; Jia, Puyou; Hu, Lihong; Zhou, Yonghong

    2018-07-01

    This work presents an efficient and environmentally friendly approach to generate hydrophobic cellulose nanocrystals (CNC) using thiol-containing castor oil (CO-SH) as a renewable hydrophobe with the assist of bio-inspired dopamine at room temperature. The modification process included the formation of the polydopamine (PDA) buffer layer on CNC surfaces and the Michael addition reaction between the catechol moieties of PDA coating and thiol groups of CO-SH. The morphology, crystalline structure, surface chemistry, thermal stability and hydrophobicity of the modified CNC were charactered by TEM, XRD, FT-IR, solid-state 13 C NMR, XPS, TGA and contact angle analysis. The modified CNC preserved cellulose crystallinity, displayed higher thermal stability than unmodified CNC, and was highly hydrophobic with a water contact angle of 95.6°. The simplicity and versatility of the surface modification strategy inspired by adhesive protein of mussel may promote rapid development of hydrophobic bio-based nanomaterials for various applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Design and Analysis of a Bio-Inspired Wire-Driven Multi-Section Flexible Robot

    Directory of Open Access Journals (Sweden)

    Zheng Li

    2013-04-01

    Full Text Available This paper presents a bio-inspired wire-driven multi-section flexible robot. It is inspired by the snake skeleton and octopus arm muscle arrangements. The robot consists of three sections and each section is made up of several identical vertebras, which are articulated by both spherical joints and a flexible backbone. Each section is driven by two groups of wires, controlling the bending motion in X and Y directions. This design integrates the serpentine robots' structure and the continuum robots' actuation. As a result, it is more compact than traditional serpentine robots and has a higher positioning accuracy than typical continuum soft robots, such as OctArm V. A Kinematics model and a workspace model of the robot are developed based on the piece wise constant curvature assumption. To evaluate the design, a prototype is built and experiments are carried out. The average distal end positioning error is less than 4%. Characteristics of the wire-driven robot are also discussed, including the leverage effect and the manipulability under constraint. These features makes the proposed robot well suited to confined spaces, especially for working in minimally invasive surgery, nuclear reactor pipelines, disaster debris, etc.

  11. B-iTRS: A Bio-Inspired Trusted Routing Scheme for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mingchuan Zhang

    2015-01-01

    Full Text Available In WSNs, routing algorithms need to handle dynamical changes of network topology, extra overhead, energy saving, and other requirements. Therefore, routing in WSNs is an extremely interesting and challenging issue. In this paper, we present a novel bio-inspired trusted routing scheme (B-iTRS based on ant colony optimization (ACO and Physarum autonomic optimization (PAO. For trust assessment, B-iTRS monitors neighbors’ behavior in real time, receives feedback from Sink, and then assesses neighbors’ trusts based on the acquired information. For routing scheme, each node finds routes to the Sink based on ACO and PAO. In the process of path finding, B-iTRS senses the load and trust value of each node and then calculates the link load and link trust of the found routes to support the route selection. Moreover, B-iTRS also assesses the route based on PAO to maintain the route table. Simulation results show how B-iTRS can achieve the effective performance compared to existing state-of-the-art algorithms.

  12. Hair flow sensors: from bio-inspiration to bio-mimicking—a review

    International Nuclear Information System (INIS)

    Tao, Junliang; Yu, Xiong

    2012-01-01

    A great many living beings, such as aquatics and arthropods, are equipped with highly sensitive flow sensors to help them survive in challenging environments. These sensors are excellent sources of inspiration for developing application-driven artificial flow sensors with high sensitivity and performance. This paper reviews the bio-inspirations on flow sensing in nature and the bio-mimicking efforts to emulate such sensing mechanisms in recent years. The natural flow sensing systems in aquatics and arthropods are reviewed to highlight inspirations at multiple levels such as morphology, sensing mechanism and information processing. Biomimetic hair flow sensors based on different sensing mechanisms and fabrication technologies are also reviewed to capture the recent accomplishments and to point out areas where further progress is necessary. Biomimetic flow sensors are still in their early stages. Further efforts are required to unveil the sensing mechanisms in the natural biological systems and to achieve multi-level bio-mimicking of the natural system to develop their artificial counterparts. (topical review)

  13. A wireless fatigue monitoring system utilizing a bio-inspired tree ring data tracking technique.

    Science.gov (United States)

    Bai, Shi; Li, Xuan; Xie, Zhaohui; Zhou, Zhi; Ou, Jinping

    2014-03-05

    Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is proposed. The general framework, methodology, and verification of this intelligent system are discussed in details. The rain-flow counting (RFC) method is adopted as the core algorithm which quantifies fatigue damages, and Digital Signal Processing (DSP) is introduced as the core module for data collection and analysis. Laboratory test results based on strain gauges and polyvinylidene fluoride (PVDF) sensors have shown that the developed intelligent system can provide a reliable quick feedback and early warning of fatigue failure. With the merits of low cost, high accuracy and great reliability, the developed wireless fatigue sensing system can be further applied to mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, etc.

  14. Bio-inspired adaptive feedback error learning architecture for motor control.

    Science.gov (United States)

    Tolu, Silvia; Vanegas, Mauricio; Luque, Niceto R; Garrido, Jesús A; Ros, Eduardo

    2012-10-01

    This study proposes an adaptive control architecture based on an accurate regression method called Locally Weighted Projection Regression (LWPR) and on a bio-inspired module, such as a cerebellar-like engine. This hybrid architecture takes full advantage of the machine learning module (LWPR kernel) to abstract an optimized representation of the sensorimotor space while the cerebellar component integrates this to generate corrective terms in the framework of a control task. Furthermore, we illustrate how the use of a simple adaptive error feedback term allows to use the proposed architecture even in the absence of an accurate analytic reference model. The presented approach achieves an accurate control with low gain corrective terms (for compliant control schemes). We evaluate the contribution of the different components of the proposed scheme comparing the obtained performance with alternative approaches. Then, we show that the presented architecture can be used for accurate manipulation of different objects when their physical properties are not directly known by the controller. We evaluate how the scheme scales for simulated plants of high Degrees of Freedom (7-DOFs).

  15. Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Hu Bing-Shan

    2009-09-01

    Full Text Available Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

  16. Design and Characterization of a Novel Bio-inspired Hair Flow Sensor Based on Resonant Sensing

    Science.gov (United States)

    Guo, X.; Yang, B.; Wang, Q. H.; Lu, C. F.; Hu, D.

    2018-03-01

    Flow sensors inspired by the natural hair sensing mechanism have great prospect in the research of micro-autonomous system and technology (MAST) for the three-dimensional structure characteristics with high spatial and quality utilization. A novel bio-inspired hair flow sensor (BHFS) based on resonant sensing with a unique asymmetric design is presented in this paper. A hair transducer and a signal detector which is constituted of a two-stage micro-leverage mechanism and two symmetrical resonators (double ended tuning fork, DETF) are adopted to realize the high sensitivity to air flow. The sensitivity of the proposed BHFS is improved significantly than the published ones due to the high sensitivity of resonators and the higher amplification factor possessed by the two-stage micro-leverage mechanism. The standard deep dry silicon on glass (DDSOG) process is chosen to fabricate the proposed BHFS. The experiment result demonstrates that the fabricated BHFS has a mechanical sensitivity of 5.26 Hz/(m/s)2 at a resonant frequency of 22 kHz with the hair height of 6 mm.

  17. Working principle of bio-inspired shape memory alloy composite actuators

    International Nuclear Information System (INIS)

    Smith, Colin; Villanueva, Alex; Joshi, Keyur; Tadesse, Yonas; Priya, Shashank

    2011-01-01

    Recently, bio-inspired shape memory alloy composite (BISMAC) actuators have been shown to mimic the deformation characteristics of natural jellyfish medusa. In this study, a constant cross-section BISMAC actuator was characterized in terms of bending deflection and force in conjunction with microscopy to understand its deformation mechanism. The actuator showed bending deflection of 111% with respect to the active length along with a blocking force of 0.061 N. The resulting energy density of the composite actuator was 4929 J m −3 at an input voltage and current level of 12 V and 0.7 A, respectively. For a dry-state actuator, this performance is extremely high and represents an optimum combination of force and deflection. Experiments reveal that BISMAC's performance is related to the moment induced from tip attachment of the shape memory alloy (SMA) rather than to friction within the composite structure. A physics-based model of BISMAC structure is presented which shows that the actuator is highly sensitive to the distance between the SMA wire and the incompressible component. While SMA has both stress and strain limitations, the limiting factor in BISMAC actuators is dependent on separation distance. The limiting factor in BISMAC's suitability for mimicking the performance of medusa was experimentally found to be related to the maximum 4% strain of the SMA and not its force generation. (fast track communication)

  18. Interactions of Bio-Inspired Membranes with Peptides and Peptide-Mimetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Michael Sebastiano

    2015-08-01

    Full Text Available Via Dissipative Particle Dynamics (DPD and implicit solvent coarse-grained (CG Molecular Dynamics (MD we examine the interaction of an amphiphilic cell-penetrating peptide PMLKE and its synthetic counterpart with a bio-inspired membrane. We use the DPD technique to investigate the interaction of peptide-mimetic nanoparticles, or nanopins, with a three-component membrane. The CG MD approach is used to investigate the interaction of a cell-penetrating peptide PMLKE with single-component membrane. We observe the spontaneous binding and subsequent insertion of peptide and nanopin in the membrane by using CG MD and DPD approaches, respectively. In addition, we find that the insertion of peptide and nanopins is mainly driven by the favorable enthalpic interactions between the hydrophobic components of the peptide, or nanopin, and the membrane. Our study provides insights into the mechanism underlying the interactions of amphiphilic peptide and peptide-mimetic nanoparticles with a membrane. The result of this study can be used to guide the functional integration of peptide and peptide-mimetic nanoparticles with a cell membrane.

  19. Artificial Roughness Encoding with a Bio-inspired MEMS-based Tactile Sensor Array

    Directory of Open Access Journals (Sweden)

    Calogero Maria Oddo

    2009-04-01

    Full Text Available A compliant 2x2 tactile sensor array was developed and investigated for roughness encoding. State of the art cross shape 3D MEMS sensors were integrated with polymeric packaging providing in total 16 sensitive elements to external mechanical stimuli in an area of about 20 mm2, similarly to the SA1 innervation density in humans. Experimental analysis of the bio-inspired tactile sensor array was performed by using ridged surfaces, with spatial periods from 2.6 mm to 4.1 mm, which were indented with regulated 1N normal force and stroked at constant sliding velocity from 15 mm/s to 48 mm/s. A repeatable and expected frequency shift of the sensor outputs depending on the applied stimulus and on its scanning velocity was observed between 3.66 Hz and 18.46 Hz with an overall maximum error of 1.7%. The tactile sensor could also perform contact imaging during static stimulus indentation. The experiments demonstrated the suitability of this approach for the design of a roughness encoding tactile sensor for an artificial fingerpad.

  20. Integration of bio-inspired, control-based visual and olfactory data for the detection of an elusive target

    Science.gov (United States)

    Duong, Tuan A.; Duong, Nghi; Le, Duong

    2017-01-01

    In this paper, we present an integration technique using a bio-inspired, control-based visual and olfactory receptor system to search for elusive targets in practical environments where the targets cannot be seen obviously by either sensory data. Bio-inspired Visual System is based on a modeling of extended visual pathway which consists of saccadic eye movements and visual pathway (vertebrate retina, lateral geniculate nucleus and visual cortex) to enable powerful target detections of noisy, partial, incomplete visual data. Olfactory receptor algorithm, namely spatial invariant independent component analysis, that was developed based on data of old factory receptor-electronic nose (enose) of Caltech, is adopted to enable the odorant target detection in an unknown environment. The integration of two systems is a vital approach and sets up a cornerstone for effective and low-cost of miniaturized UAVs or fly robots for future DOD and NASA missions, as well as for security systems in Internet of Things environments.

  1. Locomotion Dynamics for Bio-inspired Robots with Soft Appendages: Application to Flapping Flight and Passive Swimming

    Science.gov (United States)

    Boyer, Frédéric; Porez, Mathieu; Morsli, Ferhat; Morel, Yannick

    2017-08-01

    In animal locomotion, either in fish or flying insects, the use of flexible terminal organs or appendages greatly improves the performance of locomotion (thrust and lift). In this article, we propose a general unified framework for modeling and simulating the (bio-inspired) locomotion of robots using soft organs. The proposed approach is based on the model of Mobile Multibody Systems (MMS). The distributed flexibilities are modeled according to two major approaches: the Floating Frame Approach (FFA) and the Geometrically Exact Approach (GEA). Encompassing these two approaches in the Newton-Euler modeling formalism of robotics, this article proposes a unique modeling framework suited to the fast numerical integration of the dynamics of a MMS in both the FFA and the GEA. This general framework is applied on two illustrative examples drawn from bio-inspired locomotion: the passive swimming in von Karman Vortex Street, and the hovering flight with flexible flapping wings.

  2. Biotemplating of Luffa cylindrica sponges to self-supporting hierarchical zeolite macrostructures for bio-inspired structured catalytic reactors

    International Nuclear Information System (INIS)

    Zampieri, Alessandro; Mabande, Godwin T.P.; Selvam, Thangaraj; Schwieger, Wilhelm; Rudolph, Alexander; Hermann, Ralph; Sieber, Heino; Greil, Peter

    2006-01-01

    Biomorphic self-supporting MFI-type zeolite frameworks with hierarchical porosity and complex architecture were prepared using a 2-step (in-situ seeding and secondary crystal growth) hydrothermal synthesis in the presence of a biological template (Luffa sponge), employed as a macroscale sacrificial structure builder. The bio-inspired zeolitic replica inherited the complex spongy morphology and the intricate open-porous architecture of the biotemplate. Moreover, it exhibited reasonable mechanical stability in order to study the applicability of the biomorphic catalyst in a technical catalytic process. A bio-inspired catalytic reactor utilising the self-supporting ZSM-5 scaffold in monolithic configuration was developed in order to test the catalytic performance of the material

  3. A bio-inspired N-doped porous carbon electrocatalyst with hierarchical superstructure for efficient oxygen reduction reaction

    Science.gov (United States)

    Miao, Yue-E.; Yan, Jiajie; Ouyang, Yue; Lu, Hengyi; Lai, Feili; Wu, Yue; Liu, Tianxi

    2018-06-01

    The bio-inspired hierarchical "grape cluster" superstructure provides an effective integration of one-dimensional carbon nanofibers (CNF) with isolated carbonaceous nanoparticles into three-dimensional (3D) conductive frameworks for efficient electron and mass transfer. Herein, a 3D N-doped porous carbon electrocatalyst consisting of carbon nanofibers with grape-like N-doped hollow carbon particles (CNF@NC) has been prepared through a simple electrospinning strategy combined with in-situ growth and carbonization processes. Such a bio-inspired hierarchically organized conductive network largely facilitates both the mass diffusion and electron transfer during the oxygen reduction reactions (ORR). Therefore, the metal-free CNF@NC catalyst demonstrates superior catalytic activity with an absolute four-electron transfer mechanism, strong methanol tolerance and good long-term stability towards ORR in alkaline media.

  4. Computational Modeling in Tissue Engineering

    CERN Document Server

    2013-01-01

    One of the major challenges in tissue engineering is the translation of biological knowledge on complex cell and tissue behavior into a predictive and robust engineering process. Mastering this complexity is an essential step towards clinical applications of tissue engineering. This volume discusses computational modeling tools that allow studying the biological complexity in a more quantitative way. More specifically, computational tools can help in:  (i) quantifying and optimizing the tissue engineering product, e.g. by adapting scaffold design to optimize micro-environmental signals or by adapting selection criteria to improve homogeneity of the selected cell population; (ii) quantifying and optimizing the tissue engineering process, e.g. by adapting bioreactor design to improve quality and quantity of the final product; and (iii) assessing the influence of the in vivo environment on the behavior of the tissue engineering product, e.g. by investigating vascular ingrowth. The book presents examples of each...

  5. Osteogenic cells on bio-inspired materials for bone tissue engineering

    Czech Academy of Sciences Publication Activity Database

    Vagaská, Barbora; Bačáková, Lucie; Filová, Elena; Balík, Karel

    2010-01-01

    Roč. 59, č. 3 (2010), s. 309-322 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA106/06/1576; GA ČR GA106/09/1000; GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z30460519 Keywords : multi-phase composites * nanoroughness * bone implants Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.646, year: 2010

  6. Feasibility Study of a Bio-inspired Artificial Pancreas in Adults with Type 1 Diabetes

    Science.gov (United States)

    Herrero, Pau; El Sharkawy, Mohamed; Pesl, Peter; Jugnee, Narvada; Thomson, Hazel; Pavitt, Darrell; Toumazou, Christofer; Johnston, Desmond; Georgiou, Pantelis; Oliver, Nick

    2014-01-01

    Abstract Background: This study assesses proof of concept and safety of a novel bio-inspired artificial pancreas (BiAP) system in adults with type 1 diabetes during fasting, overnight, and postprandial conditions. In contrast to existing glucose controllers in artificial pancreas systems, the BiAP uses a control algorithm based on a mathematical model of β-cell physiology. The algorithm is implemented on a miniature silicon microchip within a portable hand-held device that interfaces the components of the artificial pancreas. Materials and Methods: In this nonrandomized open-label study each subject attended for a 6-h fasting study followed by a 13-h overnight and post-breakfast study on a separate occasion. During both study sessions the BiAP system was used, and microboluses of insulin were recommended every 5 min by the control algorithm according to subcutaneous sensor glucose levels. The primary outcome was percentage time spent in the glucose target range (3.9–10.0 mmol/L). Results: Twenty subjects (55% male; mean [SD] age, 44 [10] years; duration of diabetes, 22 [12] years; glycosylated hemoglobin, 7.4% [0.7%] [57 (7) mmol/mol]; body mass index, 25 [4] kg/m2) participated in the fasting study, and the median (interquartile range) percentage time in target range was 98.0% (90.8–100.0%). Seventeen of these subjects then participated in the overnight/postprandial study, where 70.7% (63.9–77.4%) of time was spent in the target range and, reassuringly, 0.0% (0.0–2.3%) of time was spent in hypoglycemia (<3.9 mmol/L). Conclusions: The BiAP achieves safe glycemic control during fasting, overnight, and postprandial conditions. PMID:24801544

  7. Post-capture vibration suppression of spacecraft via a bio-inspired isolation system

    Science.gov (United States)

    Dai, Honghua; Jing, Xingjian; Wang, Yu; Yue, Xiaokui; Yuan, Jianping

    2018-05-01

    Inspired by the smooth motions of a running kangaroo, a bio-inspired quadrilateral shape (BIQS) structure is proposed to suppress the vibrations of a free-floating spacecraft subject to periodic or impulsive forces, which may be encountered during on-orbit servicing missions. In particular, the BIQS structure is installed between the satellite platform and the capture mechanism. The dynamical model of the BIQS isolation system, i.e. a BIQS structure connecting the platform and the capture mechanism at each side, is established by Lagrange's equations to simulate the post-capture dynamical responses. The BIQS system suffering an impulsive force is dealt with by means of a modified version of Lagrange's equations. Furthermore, the classical harmonic balance method is used to solve the nonlinear dynamical system subject to periodic forces, while for the case under impulsive forces the numerical integration method is adopted. Due to the weightless environment in space, the present BIQS system is essentially an under-constrained dynamical system with one of its natural frequencies being identical to zero. The effects of system parameters, such as the number of layers in BIQS, stiffness, assembly angle, rod length, damping coefficient, masses of satellite platform and capture mechanism, on the isolation performance of the present system are thoroughly investigated. In addition, comparisons between the isolation performances of the presently proposed BIQS isolator and the conventional spring-mass-damper (SMD) isolator are conducted to demonstrate the advantages of the present isolator. Numerical simulations show that the BIQS system has a much better performance than the SMD system under either periodic or impulsive forces. Overall, the present BIQS isolator offers a highly efficient passive way for vibration suppressions of free-floating spacecraft.

  8. Improved Lighthill fish swimming model for bio-inspired robots - Modelling, computational aspects and experimental comparisons.

    OpenAIRE

    Porez , Mathieu; Boyer , Frédéric; Ijspeert , Auke

    2014-01-01

    International audience; The best known analytical model of swimming was originally developed by Lighthill and is known as large amplitude elongated body theory (LAEBT). Recently, this theory has been improved and adapted to robotics through a series of studies [Boyer et al., 2008, 2010; Candelier et al., 2011] ranging from hydrodynamic modelling to mobile multibody system dynamics. This article marks a further step towards the Lighthill theory. The LAEBT is ap- plied to one of the best bio-in...

  9. Parameter estimation with bio-inspired meta-heuristic optimization: modeling the dynamics of endocytosis

    Directory of Open Access Journals (Sweden)

    Tashkova Katerina

    2011-10-01

    convergence. These results hold for both real and artificial data, for all observability scenarios considered, and for all amounts of noise added to the artificial data. In sum, the meta-heuristic methods considered are suitable for estimating the parameters in the ODE model of the dynamics of endocytosis under a range of conditions: With the model and conditions being representative of parameter estimation tasks in ODE models of biochemical systems, our results clearly highlight the promise of bio-inspired meta-heuristic methods for parameter estimation in dynamic system models within system biology.

  10. Parameter estimation with bio-inspired meta-heuristic optimization: modeling the dynamics of endocytosis.

    Science.gov (United States)

    Tashkova, Katerina; Korošec, Peter; Silc, Jurij; Todorovski, Ljupčo; Džeroski, Sašo

    2011-10-11

    artificial data, for all observability scenarios considered, and for all amounts of noise added to the artificial data. In sum, the meta-heuristic methods considered are suitable for estimating the parameters in the ODE model of the dynamics of endocytosis under a range of conditions: With the model and conditions being representative of parameter estimation tasks in ODE models of biochemical systems, our results clearly highlight the promise of bio-inspired meta-heuristic methods for parameter estimation in dynamic system models within system biology.

  11. Bio-Inspired Photon Absorption and Energy Transfer for Next Generation Photovoltaic Devices

    Science.gov (United States)

    Magsi, Komal

    Nature's solar energy harvesting system, photosynthesis, serves as a model for photon absorption, spectra broadening, and energy transfer. Photosynthesis harvests light far differently than photovoltaic cells. These differences offer both engineering opportunity and scientific challenges since not all of the natural photon absorption mechanisms have been understood. In return, solar cells can be a very sensitive probe for the absorption characteristics of molecules capable of transferring charge to a conductive interface. The objective of this scientific work is the advancement of next generation photovoltaics through the development and application of natural photo-energy transfer processes. Two scientific methods were used in the development and application of enhancing photon absorption and transfer. First, a detailed analysis of photovoltaic front surface fluorescent spectral modification and light scattering by hetero-structure was conducted. Phosphor based spectral down-conversion is a well-known laser technology. The theoretical calculations presented here indicate that parasitic losses and light scattering within the spectral range are large enough to offset any expected gains. The second approach for enhancing photon absorption is based on bio-inspired mechanisms. Key to the utilization of these natural processes is the development of a detailed scientific understanding and the application of these processes to cost effective systems and devices. In this work both aspects are investigated. Dye type solar cells were prepared and tested as a function of Chlorophyll (or Sodium-Copper Chlorophyllin) and accessory dyes. Forster has shown that the fluorescence ratio of Chlorophyll is modified and broadened by separate photon absorption (sensitized absorption) through interaction with nearby accessory pigments. This work used the dye type solar cell as a diagnostic tool by which to investigate photon absorption and photon energy transfer. These experiments shed

  12. An IPMC-enabled bio-inspired bending/twisting fin for underwater applications

    International Nuclear Information System (INIS)

    Palmre, Viljar; Pugal, David; Kim, Sungjun; Kim, Kwang J; Hubbard, Joel J; Fleming, Maxwell; Leang, Kam K

    2013-01-01

    This paper discusses the design, fabrication, and characterization of an ionic polymer–metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a ‘fin’) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or ‘activating’ the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long × 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s −1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure

  13. An IPMC-enabled bio-inspired bending/twisting fin for underwater applications

    Science.gov (United States)

    Palmre, Viljar; Hubbard, Joel J.; Fleming, Maxwell; Pugal, David; Kim, Sungjun; Kim, Kwang J.; Leang, Kam K.

    2013-01-01

    This paper discusses the design, fabrication, and characterization of an ionic polymer-metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a ‘fin’) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or ‘activating’ the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long × 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s-1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure. These

  14. Constrained VPH+: a local path planning algorithm for a bio-inspired crawling robot with customized ultrasonic scanning sensor.

    Science.gov (United States)

    Rao, Akshay; Elara, Mohan Rajesh; Elangovan, Karthikeyan

    This paper aims to develop a local path planning algorithm for a bio-inspired, reconfigurable crawling robot. A detailed description of the robotic platform is first provided, and the suitability for deployment of each of the current state-of-the-art local path planners is analyzed after an extensive literature review. The Enhanced Vector Polar Histogram algorithm is described and reformulated to better fit the requirements of the platform. The algorithm is deployed on the robotic platform in crawling configuration and favorably compared with other state-of-the-art local path planning algorithms.

  15. Design of a biomass-to-biorefinery logistics system through bio-inspired metaheuristic optimization considering multiple types of feedstocks

    Science.gov (United States)

    Trueba, Isidoro

    fossil fuels to biofuels. In many ways biomass is a unique renewable resource. It can be stored and transported relatively easily in contrast to renewable options such as wind and solar, which create intermittent electrical power that requires immediate consumption and a connection to the grid. This thesis presents two different models for the design optimization of a biomass-to-biorefinery logistics system through bio-inspired metaheuristic optimization considering multiple types of feedstocks. This work compares the performance and solutions obtained by two types of metaheuristic approaches; genetic algorithm and ant colony optimization. Compared to rigorous mathematical optimization methods or iterative algorithms, metaheuristics do not guarantee that a global optimal solution can be found on some class of problems. Problems with similar characteristics to the one presented in this thesis have been previously solved using linear programming, integer programming and mixed integer programming methods. However, depending on the type of problem, these mathematical or complete methods might need exponential computation time in the worst-case. This often leads to computation times too high for practical purposes. Therefore, this thesis develops two types of metaheuristic approaches for the design optimization of a biomass-to-biorefinery logistics system considering multiple types of feedstocks and shows that metaheuristics are highly suitable to solve hard combinatorial optimization problems such as the one addressed in this research work.

  16. Control of Flow Structure on Non-Slender Delta Wing: Bio-inspired Edge Modifications, Passive Bleeding, and Pulsed Blowing

    Science.gov (United States)

    Yavuz, Mehmet Metin; Celik, Alper; Cetin, Cenk

    2016-11-01

    In the present study, different flow control approaches including bio-inspired edge modifications, passive bleeding, and pulsed blowing are introduced and applied for the flow over non-slender delta wing. Experiments are conducted in a low speed wind tunnel for a 45 degree swept delta wing using qualitative and quantitative measurement techniques including laser illuminated smoke visualization, particle image velocimety (PIV), and surface pressure measurements. For the bio-inspired edge modifications, the edges of the wing are modified to dolphin fluke geometry. In addition, the concept of flexion ratio, a ratio depending on the flexible length of animal propulsors such as wings, is introduced. For passive bleeding, directing the free stream air from the pressure side of the planform to the suction side of the wing is applied. For pulsed blowing, periodic air injection through the leading edge of the wing is performed in a square waveform with 25% duty cycle at different excitation frequencies and compared with the steady and no blowing cases. The results indicate that each control approach is quite effective in terms of altering the overall flow structure on the planform. However, the success level, considering the elimination of stall or delaying the vortex breakdown, depends on the parameters in each method.

  17. One-pot Synthesis of Bio-inspired Layered Materials of 3D Graphene Network/Calcium Carbonate

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing; FU Zhengyi; YAO Bin; PING Hang; YU Hongjian; ZHANG Fan; ZHANG Jinyong; WANG Yucheng; WANG Hao; WANG Weimin

    2017-01-01

    A bio-inspired layered material of reduced graphene oxide (RGOs) and calcium carbonate was synthesized via a one-pot strategy in DMF/H2O mixed solvent. The experimental results show that the product is a layered material of wrinkled RGOs networks and micron-sized calcium carbonate particles with uniform granular diameter and homogeneous morphology, which are distributed between the layered gallery of the graphene scaffold. The polymorph and the morphology of the in-situ produced calcium carbonate particles can be manipulated by simply changing the temperature scheme. Besides, the graphene oxide was reduced to a certain extent, and the hierarchical wrinkles were generated in the RGOs layer by the in-situ formation of the calcium carbonate particles. This work provides a facile and controllable strategy for synthesizing layered material of RGOs and carbonates, and also presents a platform for making three-dimensional porous wrinkled RGOs networks.

  18. Extensive Investigations on Bio-Inspired Trust and Reputation Model over Hops Coefficient Factor in Distributed Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Vinod Kumar Verma

    2014-08-01

    Full Text Available Resource utilization requires a substantial consideration for a trust and reputation model to be deployed within a wireless sensor network (WSN. In the evaluation, our attention is focused on the effect of hops coefficient factor estimation on WSN with bio-inspired trust and reputation model (BTRM. We present the state-of-the-art system level evaluation of accuracy and path length of sensor node operations for their current and average scenarios. Additionally, we emphasized over the energy consumption evaluation for static, dynamic and oscillatory modes of BTRM-WSN model. The performance of the hops coefficient factor for our proposed framework is evaluated via analytic bounds and numerical simulations.

  19. Bio-inspired citrate functionalized apatite coating on rapid prototyped titanium scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Peng [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Lu, Fang [School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006 (China); Zhu, Wenjun [Department of Prosthodontics, Guanghua School of Stomatology, Guang Dong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Wang, Di [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Zhu, Xiaojing [Department of Prosthodontics, Guanghua School of Stomatology, Guang Dong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Tan, Guoxin, E-mail: tanguoxin@126.com [Institute of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Wang, Xiaolan [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Zhang, Yu; Li, Lihua [General Hospital of Guangzhou Military Command of PLA, Guangzhou 510010 (China); Ning, Chengyun, E-mail: imcyning@scut.edu.cn [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China)

    2014-09-15

    Highlights: • Designed and reproducible porous titanium scaffolds were produced. • Hydrophilic nanoporous film was built on scaffold. • Apatite coating was deposited on scaffold under the modulation of citrate ions. • Citrate ions could affect CO{sub 3}{sup 2−} incorporation in apatite coatings. - Abstract: Scaffold functionalized with appropriate osteogenic coatings can significantly improve implant-bone response. In this study, with designed model and optimized manufacture parameters, reproducible and precise titanium scaffolds were produced. Reconstructed three-dimensional image and sectional structure of the scaffold were examined by micro-computed tomography and relative software. Alkali treatment was carried out on these manufactured porous scaffolds to produce nanoporous hydrophilic film. After 6 days deposition in simulated body fluid (SBF) containing sodium citrate (SC-SBF), plate-like amorphous calcium phosphate (ACP) coating was deposited on scaffold surface. Ultrasonication tests qualitatively indicated an enhanced adhesion force of apatite coatings deposited in SC-SBF compared to that deposited in SBF. And the effect of citrate ions on the CO{sub 3}{sup 2−} incorporation rate in apatite coating was quantitatively examined by bending vibration of CO{sub 3}{sup 2−} at ∼874 cm{sup −1}. Results indicated the highest carbonate content was obtained at the citrate ion concentration of 6 × 10{sup −5} mol/L in SC-SBF. These three-dimensional porous titanium-apatite hybrid scaffolds are expected to find application in bone tissue regeneration.

  20. Characterization and prediction of the backscattered form function of an immersed cylindrical shell using hybrid fuzzy clustering and bio-inspired algorithms.

    Science.gov (United States)

    Agounad, Said; Aassif, El Houcein; Khandouch, Younes; Maze, Gérard; Décultot, Dominique

    2018-02-01

    The acoustic scattering of a plane wave by an elastic cylindrical shell is studied. A new approach is developed to predict the form function of an immersed cylindrical shell of the radius ratio b/a ('b' is the inner radius and 'a' is the outer radius). The prediction of the backscattered form function is investigated by a combined approach between fuzzy clustering algorithms and bio-inspired algorithms. Four famous fuzzy clustering algorithms: the fuzzy c-means (FCM), the Gustafson-Kessel algorithm (GK), the fuzzy c-regression model (FCRM) and the Gath-Geva algorithm (GG) are combined with particle swarm optimization and genetic algorithm. The symmetric and antisymmetric circumferential waves A, S 0 , A 1 , S 1 and S 2 are investigated in a reduced frequency (k 1 a) range extends over 0.1computational results show that the proposed approach is very efficient to predict the form function and consequently, for acoustic characterization purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Hypercell : A bio-inspired information design framework for real-time adaptive spatial components

    NARCIS (Netherlands)

    Biloria, N.M.; Chang, J.R.

    2012-01-01

    Contemporary explorations within the evolutionary computational domain have been heavily instrumental in exploring biological processes of adaptation, growth and mutation. On the other hand a plethora of designers owing to the increasing sophistication in computer aided design software are equally

  2. In Situ Atomic Force Microscopy Studies on Nucleation and Self-Assembly of Biogenic and Bio-Inspired Materials

    Directory of Open Access Journals (Sweden)

    Cheng Zeng

    2017-08-01

    Full Text Available Through billions of years of evolution, nature has been able to create highly sophisticated and ordered structures in living systems, including cells, cellular components and viruses. The formation of these structures involves nucleation and self-assembly, which are fundamental physical processes associated with the formation of any ordered structure. It is important to understand how biogenic materials self-assemble into functional and highly ordered structures in order to determine the mechanisms of biological systems, as well as design and produce new classes of materials which are inspired by nature but equipped with better physiochemical properties for our purposes. An ideal tool for the study of nucleation and self-assembly is in situ atomic force microscopy (AFM, which has been widely used in this field and further developed for different applications in recent years. The main aim of this work is to review the latest contributions that have been reported on studies of nucleation and self-assembly of biogenic and bio-inspired materials using in situ AFM. We will address this topic by introducing the background of AFM, and discussing recent in situ AFM studies on nucleation and self-assembly of soft biogenic, soft bioinspired and hard materials.

  3. A Bio-Inspired Model-Based Approach for Context-Aware Post-WIMP Tele-Rehabilitation

    Directory of Open Access Journals (Sweden)

    Víctor López-Jaquero

    2016-10-01

    Full Text Available Tele-rehabilitation is one of the main domains where Information and Communication Technologies (ICT have been proven useful to move healthcare from care centers to patients’ home. Moreover, patients, especially those carrying out a physical therapy, cannot use a traditional Window, Icon, Menu, Pointer (WIMP system, but they need to interact in a natural way, that is, there is a need to move from WIMP systems to Post-WIMP ones. Moreover, tele-rehabilitation systems should be developed following the context-aware approach, so that they are able to adapt to the patients’ context to provide them with usable and effective therapies. In this work a model-based approach is presented to assist stakeholders in the development of context-aware Post-WIMP tele-rehabilitation systems. It entails three different models: (i a task model for designing the rehabilitation tasks; (ii a context model to facilitate the adaptation of these tasks to the context; and (iii a bio-inspired presentation model to specify thoroughly how such tasks should be performed by the patients. Our proposal overcomes one of the limitations of the model-based approach for the development of context-aware systems supporting the specification of non-functional requirements. Finally, a case study is used to illustrate how this proposal can be put into practice to design a real world rehabilitation task.

  4. Obstacle traversal and self-righting of bio-inspired robots reveal the physics of multi-modal locomotion

    Science.gov (United States)

    Li, Chen; Fearing, Ronald; Full, Robert

    Most animals move in nature in a variety of locomotor modes. For example, to traverse obstacles like dense vegetation, cockroaches can climb over, push across, reorient their bodies to maneuver through slits, or even transition among these modes forming diverse locomotor pathways; if flipped over, they can also self-right using wings or legs to generate body pitch or roll. By contrast, most locomotion studies have focused on a single mode such as running, walking, or jumping, and robots are still far from capable of life-like, robust, multi-modal locomotion in the real world. Here, we present two recent studies using bio-inspired robots, together with new locomotion energy landscapes derived from locomotor-environment interaction physics, to begin to understand the physics of multi-modal locomotion. (1) Our experiment of a cockroach-inspired legged robot traversing grass-like beam obstacles reveals that, with a terradynamically ``streamlined'' rounded body like that of the insect, robot traversal becomes more probable by accessing locomotor pathways that overcome lower potential energy barriers. (2) Our experiment of a cockroach-inspired self-righting robot further suggests that body vibrations are crucial for exploring locomotion energy landscapes and reaching lower barrier pathways. Finally, we posit that our new framework of locomotion energy landscapes holds promise to better understand and predict multi-modal biological and robotic movement.

  5. Bio-inspired micro-nano structured surface with structural color and anisotropic wettability on Cu substrate

    International Nuclear Information System (INIS)

    Liu, Yan; Li, Shuyi; Niu, Shichao; Cao, Xiaowen; Han, Zhiwu; Ren, Luquan

    2016-01-01

    Highlights: • We have prepared a biomimetic hydrophobic surface on copper substrate by one-step femtosecond laser technique. • The hydrophobicity mechanism relies on morphology and chemical component on surface. • The hydrophobic surfaces exhibit different structural colors and a anisotropic wettability. - Abstract: Inspired by the unique creatures in the nature, the femtosecond laser technology has been usually used to fabricate the periodic microstructures due to its advantages of rapidness, simplicity, ease of large-area fabrication, and simultaneously offering dual micro/nano-scale structures simply via one-step process for a wide variety of materials. By changing the experimental conditions, multi-functional surfaces which possess superhydrophobicity and structural colors could be achieved on copper substrate. In addition, the apparent contact angle can reach 144.3° without any further modification, which also exhibits the anisotropic wettability. Moreover, it can be inferred that higher laser fluence can lead to a larger CA within a certain range. At the same time, due to the change of laser processing parameters, the obtained surfaces present different structural colors. This study may expand the applications of bio-inspired functional materials because multiple colors and hydrophobicity are both important features in the real life and industrial applications, such as display, decoration, and anti-counterfeiting technology etc.

  6. Bio-inspired nano-photodiode for Low Light, High Resolution and crosstalk-free CMOS image sensing

    KAUST Repository

    Saffih, Faycal

    2011-05-01

    Previous attempts have been devoted to mimic biological vision intelligence at the architectural system level. In this paper, a novel imitation of biological visual system intelligence is suggested, at the device level with the introduction of novel photodiode morphology. The proposed bio-inspired nanorod photodiode puts the depletion region length on the path of the incident photon instead of on its width, as the case is with the planar photodiodes. The depletion region has a revolving volume to increase the photodiode responsivity, and thus its photosensitivity. In addition, it can virtually boost the pixel fill factor (FF) above the 100% classical limit due to decoupling of its vertical sensing area from its limited planar circuitry area. Furthermore, the suggested nanorod photodiode photosensitivity is analytically proven to be higher than that of the planar photodiode. We also show semi-empirically that the responsivity of the suggested device varies linearly with its height; this important feature has been confirmed using Sentaurus simulation. The proposed nano-photorod is believed to meet the increasingly stringent High-Resolution-Low-Light (HRLL) detection requirements of the camera-phone and biomedical imaging markets. © 2011 IEEE.

  7. Mimicking the cell membrane: bio-inspired simultaneous functions with monovalent anion selectivity and antifouling properties of anion exchange membrane

    Science.gov (United States)

    Zhao, Yan; Liu, Huimin; Tang, Kaini; Jin, Yali; Pan, Jiefeng; der Bruggen, Bart Van; Shen, Jiangnan; Gao, Congjie

    2016-11-01

    A new bio-inspired method was applied in this study to simultaneously improve the monovalent anion selectivity and antifouling properties of anion exchange membranes (AEMs). Three-layer architecture was developed by deposition of polydopamine (PDA) and electro-deposition of N-O-sulfonic acid benzyl chitosan (NSBC). The innermost and outermost layers were PDA with different deposition time. The middle layer was prepared by NSBC. Fourier transform infrared spectroscopy and scanning electron microscopy confirmed that PDA and NSBC were successfully modified on the surfaces of AEMs. The contact angle of the membranes indicated an improved hydrophilicity of the modified membranes. A series of electrodialysis experiments in which Cl-/SO42- separation was studied, demonstrating the monovalent anion selectivity of the samples. The Cl-/SO42- permselectivity of the modified membranes can reach up to 2.20, higher than that of the commercial membrane (only 0.78) during 90 minutes in electrodialysis (ED). The increase value of the resistance of the membranes was also measured to evaluate the antifouling properties. Sodium dodecyl benzene sulfonate (SDBS) was used as the fouling material in the ED process and the membrane area resistance of modified membrane increase value of was only 0.08 Ωcm2 30 minutes later.

  8. An Advanced Bio-Inspired PhotoPlethysmoGraphy (PPG) and ECG Pattern Recognition System for Medical Assessment.

    Science.gov (United States)

    Rundo, Francesco; Conoci, Sabrina; Ortis, Alessandro; Battiato, Sebastiano

    2018-01-30

    Physiological signals are widely used to perform medical assessment for monitoring an extensive range of pathologies, usually related to cardio-vascular diseases. Among these, both PhotoPlethysmoGraphy (PPG) and Electrocardiography (ECG) signals are those more employed. PPG signals are an emerging non-invasive measurement technique used to study blood volume pulsations through the detection and analysis of the back-scattered optical radiation coming from the skin. ECG is the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin. In the present paper we propose a physiological ECG/PPG "combo" pipeline using an innovative bio-inspired nonlinear system based on a reaction-diffusion mathematical model, implemented by means of the Cellular Neural Network (CNN) methodology, to filter PPG signal by assigning a recognition score to the waveforms in the time series. The resulting "clean" PPG signal exempts from distortion and artifacts is used to validate for diagnostic purpose an EGC signal simultaneously detected for a same patient. The multisite combo PPG-ECG system proposed in this work overpasses the limitations of the state of the art in this field providing a reliable system for assessing the above-mentioned physiological parameters and their monitoring over time for robust medical assessment. The proposed system has been validated and the results confirmed the robustness of the proposed approach.

  9. Strong Quantum Confinement Effects and Chiral Excitons in Bio-Inspired ZnO–Amino Acid Cocrystals

    KAUST Repository

    Muhammed, Madathumpady Abubaker Habeeb

    2018-02-20

    Elucidating the underlying principles behind band gap engineering is paramount for the successful implementation of semiconductors in photonic and optoelectronic devices. Recently it has been shown that the band gap of a wide and direct band gap semiconductor, such as ZnO, can be modified upon cocrystallization with amino acids, with the role of the biomolecules remaining unclear. Here, by probing and modeling the light-emitting properties of ZnO-amino acid cocrystals, we identify the amino acids\\' role on this band gap modulation and demonstrate their effective chirality transfer to the interband excitations in ZnO. Our 3D quantum model suggests that the strong band edge emission blue-shift in the cocrystals can be explained by a quasi-periodic distribution of amino acid potential barriers within the ZnO crystal lattice. Overall, our findings indicate that biomolecule cocrystallization can be used as a truly bio-inspired means to induce chiral quantum confinement effects in quasi-bulk semiconductors.

  10. Mimicking the cell membrane: bio-inspired simultaneous functions with monovalent anion selectivity and antifouling properties of anion exchange membrane

    Science.gov (United States)

    Zhao, Yan; Liu, Huimin; Tang, Kaini; Jin, Yali; Pan, Jiefeng; der Bruggen, Bart Van; Shen, Jiangnan; Gao, Congjie

    2016-01-01

    A new bio-inspired method was applied in this study to simultaneously improve the monovalent anion selectivity and antifouling properties of anion exchange membranes (AEMs). Three-layer architecture was developed by deposition of polydopamine (PDA) and electro-deposition of N-O-sulfonic acid benzyl chitosan (NSBC). The innermost and outermost layers were PDA with different deposition time. The middle layer was prepared by NSBC. Fourier transform infrared spectroscopy and scanning electron microscopy confirmed that PDA and NSBC were successfully modified on the surfaces of AEMs. The contact angle of the membranes indicated an improved hydrophilicity of the modified membranes. A series of electrodialysis experiments in which Cl−/SO42− separation was studied, demonstrating the monovalent anion selectivity of the samples. The Cl−/SO42− permselectivity of the modified membranes can reach up to 2.20, higher than that of the commercial membrane (only 0.78) during 90 minutes in electrodialysis (ED). The increase value of the resistance of the membranes was also measured to evaluate the antifouling properties. Sodium dodecyl benzene sulfonate (SDBS) was used as the fouling material in the ED process and the membrane area resistance of modified membrane increase value of was only 0.08 Ωcm2 30 minutes later. PMID:27853255

  11. Bio-inspired piezoelectric linear motor driven by a single-phase harmonic wave with an asymmetric stator.

    Science.gov (United States)

    Pan, Qiaosheng; Miao, Enming; Wu, Bingxuan; Chen, Weikang; Lei, Xiujun; He, Liangguo

    2017-07-01

    A novel, bio-inspired, single-phase driven piezoelectric linear motor (PLM) using an asymmetric stator was designed, fabricated, and tested to avoid mode degeneracy and to simplify the drive mechanism of a piezoelectric motor. A piezoelectric transducer composed of two piezoelectric stacks and a displacement amplifier was used as the driving element of the PLM. Two simple and specially designed claws performed elliptical motion. A numerical simulation was performed to design the stator and determine the feasibility of the design mechanism of the PLM. Moreover, an experimental setup was built to validate the working principles, as well as to evaluate the performance, of the PLM. The prototype motor outputs a no-load speed of 233.7 mm/s at a voltage of 180 V p-p and a maximum thrust force of 2.3 N under a preload of 10 N. This study verified the feasibility of the proposed design and provided a method to simplify the driving harmonic signal and structure of PLMs.

  12. Bio-inspired Plasmonic Nanoarchitectured Hybrid System Towards Enhanced Far Red-to-Near Infrared Solar Photocatalysis

    Science.gov (United States)

    Yan, Runyu; Chen, Min; Zhou, Han; Liu, Tian; Tang, Xingwei; Zhang, Ke; Zhu, Hanxing; Ye, Jinhua; Zhang, Di; Fan, Tongxiang

    2016-01-01

    Solar conversion to fuels or to electricity in semiconductors using far red-to-near infrared (NIR) light, which accounts for about 40% of solar energy, is highly significant. One main challenge is the development of novel strategies for activity promotion and new basic mechanisms for NIR response. Mother Nature has evolved to smartly capture far red-to-NIR light via their intelligent systems due to unique micro/nanoarchitectures, thus motivating us for biomimetic design. Here we report the first demonstration of a new strategy, based on adopting nature’s far red-to-NIR responsive architectures for an efficient bio-inspired photocatalytic system. The system is constructed by controlled assembly of light-harvesting plasmonic nanoantennas onto a typical photocatalytic unit with butterfly wings’ 3D micro/nanoarchitectures. Experiments and finite-difference time-domain (FDTD) simulations demonstrate the structural effects on obvious far red-to-NIR photocatalysis enhancement, which originates from (1) Enhancing far red-to-NIR (700~1200 nm) harvesting, up to 25%. (2) Enhancing electric-field amplitude of localized surface plasmon (LSPs) to more than 3.5 times than that of the non-structured one, which promotes the rate of electron-hole pair formation, thus substantially reinforcing photocatalysis. This proof-of-concept study provides a new methodology for NIR photocatalysis and would potentially guide future conceptually new NIR responsive system designs.

  13. Enhancing thermal reliability of fiber-optic sensors for bio-inspired applications at ultra-high temperatures

    International Nuclear Information System (INIS)

    Kang, Donghoon; Kim, Heon-Young; Kim, Dae-Hyun

    2014-01-01

    The rapid growth of bio-(inspired) sensors has led to an improvement in modern healthcare and human–robot systems in recent years. Higher levels of reliability and better flexibility, essential features of these sensors, are very much required in many application fields (e.g. applications at ultra-high temperatures). Fiber-optic sensors, and fiber Bragg grating (FBG) sensors in particular, are being widely studied as suitable sensors for improved structural health monitoring (SHM) due to their many merits. To enhance the thermal reliability of FBG sensors, thermal sensitivity, generally expressed as α f + ξ f and considered a constant, should be investigated more precisely. For this purpose, the governing equation of FBG sensors is modified using differential derivatives between the wavelength shift and the temperature change in this study. Through a thermal test ranging from RT to 900 °C, the thermal sensitivity of FBG sensors is successfully examined and this guarantees thermal reliability of FBG sensors at ultra-high temperatures. In detail, α f + ξ f has a non-linear dependence on temperature and varies from 6.0 × 10 −6  °C −1 (20 °C) to 10.6 × 10 −6  °C −1 (650 °C). Also, FBGs should be carefully used for applications at ultra-high temperatures due to signal disappearance near 900 °C. (paper)

  14. Enhancing thermal reliability of fiber-optic sensors for bio-inspired applications at ultra-high temperatures

    Science.gov (United States)

    Kang, Donghoon; Kim, Heon-Young; Kim, Dae-Hyun

    2014-07-01

    The rapid growth of bio-(inspired) sensors has led to an improvement in modern healthcare and human-robot systems in recent years. Higher levels of reliability and better flexibility, essential features of these sensors, are very much required in many application fields (e.g. applications at ultra-high temperatures). Fiber-optic sensors, and fiber Bragg grating (FBG) sensors in particular, are being widely studied as suitable sensors for improved structural health monitoring (SHM) due to their many merits. To enhance the thermal reliability of FBG sensors, thermal sensitivity, generally expressed as αf + ξf and considered a constant, should be investigated more precisely. For this purpose, the governing equation of FBG sensors is modified using differential derivatives between the wavelength shift and the temperature change in this study. Through a thermal test ranging from RT to 900 °C, the thermal sensitivity of FBG sensors is successfully examined and this guarantees thermal reliability of FBG sensors at ultra-high temperatures. In detail, αf + ξf has a non-linear dependence on temperature and varies from 6.0 × 10-6 °C-1 (20 °C) to 10.6 × 10-6 °C-1 (650 °C). Also, FBGs should be carefully used for applications at ultra-high temperatures due to signal disappearance near 900 °C.

  15. Bio-inspired Plasmonic Nanoarchitectured Hybrid System Towards Enhanced Far Red-to-Near Infrared Solar Photocatalysis.

    Science.gov (United States)

    Yan, Runyu; Chen, Min; Zhou, Han; Liu, Tian; Tang, Xingwei; Zhang, Ke; Zhu, Hanxing; Ye, Jinhua; Zhang, Di; Fan, Tongxiang

    2016-01-28

    Solar conversion to fuels or to electricity in semiconductors using far red-to-near infrared (NIR) light, which accounts for about 40% of solar energy, is highly significant. One main challenge is the development of novel strategies for activity promotion and new basic mechanisms for NIR response. Mother Nature has evolved to smartly capture far red-to-NIR light via their intelligent systems due to unique micro/nanoarchitectures, thus motivating us for biomimetic design. Here we report the first demonstration of a new strategy, based on adopting nature's far red-to-NIR responsive architectures for an efficient bio-inspired photocatalytic system. The system is constructed by controlled assembly of light-harvesting plasmonic nanoantennas onto a typical photocatalytic unit with butterfly wings' 3D micro/nanoarchitectures. Experiments and finite-difference time-domain (FDTD) simulations demonstrate the structural effects on obvious far red-to-NIR photocatalysis enhancement, which originates from (1) Enhancing far red-to-NIR (700~1200 nm) harvesting, up to 25%. (2) Enhancing electric-field amplitude of localized surface plasmon (LSPs) to more than 3.5 times than that of the non-structured one, which promotes the rate of electron-hole pair formation, thus substantially reinforcing photocatalysis. This proof-of-concept study provides a new methodology for NIR photocatalysis and would potentially guide future conceptually new NIR responsive system designs.

  16. Righting and turning in mid-air using appendage inertia: reptile tails, analytical models and bio-inspired robots

    International Nuclear Information System (INIS)

    Jusufi, A; Full, R J; Kawano, D T; Libby, T

    2010-01-01

    Unlike the falling cat, lizards can right themselves in mid-air by a swing of their large tails in one direction causing the body to rotate in the other. Here, we developed a new three-dimensional analytical model to investigate the effectiveness of tails as inertial appendages that change body orientation. We anchored our model using the morphological parameters of the flat-tailed house gecko Hemidactylus platyurus. The degree of roll in air righting and the amount of yaw in mid-air turning directly measured in house geckos matched the model's results. Our model predicted an increase in body roll and turning as tails increase in length relative to the body. Tails that swung from a near orthogonal plane relative to the body (i.e. 0-30 0 from vertical) were the most effective at generating body roll, whereas tails operating at steeper angles (i.e. 45-60 0 ) produced only half the rotation. To further test our analytical model's predictions, we built a bio-inspired robot prototype. The robot reinforced how effective attitude control can be attained with simple movements of an inertial appendage.

  17. Righting and turning in mid-air using appendage inertia: reptile tails, analytical models and bio-inspired robots

    Energy Technology Data Exchange (ETDEWEB)

    Jusufi, A; Full, R J [Department of Integrative Biology, University of California, Berkeley, CA 94720-3140 (United States); Kawano, D T [Department of Mechanical Engineering, University of California, Berkeley, CA 94720-1740 (United States); Libby, T, E-mail: ardianj@berkeley.ed [Center for Interdisciplinary Bio-inspiration in Education and Research, University of California, Berkeley, CA 94720-3140 (United States)

    2010-12-15

    Unlike the falling cat, lizards can right themselves in mid-air by a swing of their large tails in one direction causing the body to rotate in the other. Here, we developed a new three-dimensional analytical model to investigate the effectiveness of tails as inertial appendages that change body orientation. We anchored our model using the morphological parameters of the flat-tailed house gecko Hemidactylus platyurus. The degree of roll in air righting and the amount of yaw in mid-air turning directly measured in house geckos matched the model's results. Our model predicted an increase in body roll and turning as tails increase in length relative to the body. Tails that swung from a near orthogonal plane relative to the body (i.e. 0-30{sup 0} from vertical) were the most effective at generating body roll, whereas tails operating at steeper angles (i.e. 45-60{sup 0}) produced only half the rotation. To further test our analytical model's predictions, we built a bio-inspired robot prototype. The robot reinforced how effective attitude control can be attained with simple movements of an inertial appendage.

  18. Fabricating bio-inspired micro/nano-particles by polydopamine coating and surface interactions with blood platelets

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Wei [Jiangsu Provincial Key Lab for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Shi, Qiang, E-mail: shiqiang@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Hou, Jianwen; Gao, Jian; Li, Chunming; Jin, Jing; Shi, Hengchong [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin, Jinghua, E-mail: yinjh@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2015-10-01

    Graphical abstract: The particles or particle aggregations activate the blood platelets and provide the physical adhesive sites for platelets adhesion. - Highlights: • Particles with varied sizes and surface properties were fabricated by facile polydopamine (PDA) coating on polystyrene microsphere. • The direct interaction between PDA particles and blood platelets was qualitatively investigated. • The knowledge on platelet–particle interactions provided the basic principle to select biocompatible micro/nano-particles in biomedical field. - Abstract: Although bio-inspired polydopamine (PDA) micro/nano-particles show great promise for biomedical applications, the knowledge on the interactions between micro/nano-particles and platelets is still lacking. Here, we fabricate PDA-coated micro/nano-particles and investigate the platelet–particle surface interactions. Our strategy takes the advantage of facile PDA coating on polystyrene (PS) microsphere to fabricate particles with varied sizes and surface properties, and the chemical reactivity of PDA layers to immobilize fibrinogen and bovine serum albumin to manipulate platelet activation and adhesion. We demonstrate that PS particles activate the platelets in the size-dependent manner, but PDA nanoparticles have slight effect on platelet activation; PS particles promote platelet adhesion while PDA particles reduce platelet adhesion on the patterned surface; Particles interact with platelets through activating the glycoprotein integrin receptor of platelets and providing physical sites for initial platelet adhesion. Our work sheds new light on the interaction between platelets and particles, which provides the basic principle to select biocompatible micro/nano-particles in biomedical field.

  19. Bio-inspired micro-nano structured surface with structural color and anisotropic wettability on Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130022 (China); Li, Shuyi; Niu, Shichao [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Cao, Xiaowen [Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Han, Zhiwu, E-mail: zwhan@jlu.edu.cn [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Ren, Luquan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China)

    2016-08-30

    Highlights: • We have prepared a biomimetic hydrophobic surface on copper substrate by one-step femtosecond laser technique. • The hydrophobicity mechanism relies on morphology and chemical component on surface. • The hydrophobic surfaces exhibit different structural colors and a anisotropic wettability. - Abstract: Inspired by the unique creatures in the nature, the femtosecond laser technology has been usually used to fabricate the periodic microstructures due to its advantages of rapidness, simplicity, ease of large-area fabrication, and simultaneously offering dual micro/nano-scale structures simply via one-step process for a wide variety of materials. By changing the experimental conditions, multi-functional surfaces which possess superhydrophobicity and structural colors could be achieved on copper substrate. In addition, the apparent contact angle can reach 144.3° without any further modification, which also exhibits the anisotropic wettability. Moreover, it can be inferred that higher laser fluence can lead to a larger CA within a certain range. At the same time, due to the change of laser processing parameters, the obtained surfaces present different structural colors. This study may expand the applications of bio-inspired functional materials because multiple colors and hydrophobicity are both important features in the real life and industrial applications, such as display, decoration, and anti-counterfeiting technology etc.

  20. Carbon-Nanotube-Supported Bio-Inspired Nickel Catalyst and Its Integration in Hybrid Hydrogen/Air Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gentil, Solène [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, CNRS UMR5249, CEA, 38000 Grenoble France; Lalaoui, Noémie [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Dutta, Arnab [Pacific Northwest National Laboratory, Richland WA 99532 USA; Current address: Chemistry Department, IIT Gandhinagar, Gujarat 382355 India; Nedellec, Yannig [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Cosnier, Serge [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Shaw, Wendy J. [Pacific Northwest National Laboratory, Richland WA 99532 USA; Artero, Vincent [Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, CNRS UMR5249, CEA, 38000 Grenoble France; Le Goff, Alan [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France

    2017-01-12

    A biomimetic nickel bis-diphosphine complex incorporating the amino-acid arginine in the outer coordination sphere, was immobilized on modified single-wall carbon nanotubes (SWCNTs) through electrostatic interactions. The sur-face-confined catalyst is characterized by a reversible 2-electron/2-proton redox process at potentials close to the equibrium potential of the H+/H2 couple. Consequently, the functionalized redox nanomaterial exhibits reversible electrocatalytic activity for the H2/2H+ interconversion over a broad range of pH. This system exhibits catalytic bias, analogous to hydrogenases, resulting in high turnover frequencies at low overpotentials for electrocatalytic H2 oxida-tion between pH 0 and 7. This allowed integrating such bio-inspired nanomaterial together with a multicopper oxi-dase at the cathode side in a hybrid bioinspired/enzymatic hydrogen fuel cell. This device delivers ~2 mW cm–2 with an open-circuit voltage of 1.0 V at room temperature and pH 5, which sets a new efficiency record for a bio-related hydrogen fuel cell with base metal catalysts.

  1. Bio-inspired green synthesis of Fe3O4 magnetic nanoparticles using watermelon rinds and their catalytic activity

    Science.gov (United States)

    Prasad, Ch.; Gangadhara, S.; Venkateswarlu, P.

    2016-08-01

    Novel and bio-inspired magnetic nanoparticles were synthesized using watermelon rinds (WR) which are nontoxic and biodegradable. Watermelon rind extract was used as a solvent and capping and reducing agent in the synthesis. The Fe3o4 MNPs were characterized by using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer techniques (VSM). XRD studies revealed a high degree of crystalline and monophasic Fe nanoparticles of face-centered cubic stricture. FTIR analysis proved that particles are reduced and stabilized in solution by the capping agent that is likely to be proteins secreted by the biomass. The present process in an excellent candidate for the synthesis of iron nanoparticles that is simple, easy to execute, pollutant free and inexpensive. A practical and convenient method for the synthesis of highly stable and small-sized iron nanoparticles with a narrow distribution from 2 to 20 nm is reported. Also, the MNPs present in higher saturation magnetization (Ms) of 14.2 emu/g demonstrate tremendous magnetic response behavior. However, the synthesized iron nanoparticles were used as a catalyst for the preparation of biologically interesting 2-oxo-1,2,3,4-tetrahydropyrimidine derivatives in high yields. These results exhibited that the synthesized Fe3O4 MNPs could be used as a catalyst in organic synthesis.

  2. Carbon-Nanotube-Supported Bio-Inspired Nickel Catalyst and Its Integration in Hybrid Hydrogen/Air Fuel Cells.

    Science.gov (United States)

    Gentil, Solène; Lalaoui, Noémie; Dutta, Arnab; Nedellec, Yannig; Cosnier, Serge; Shaw, Wendy J; Artero, Vincent; Le Goff, Alan

    2017-02-06

    A biomimetic nickel bis-diphosphine complex incorporating the amino acid arginine in the outer coordination sphere was immobilized on modified carbon nanotubes (CNTs) through electrostatic interactions. The functionalized redox nanomaterial exhibits reversible electrocatalytic activity for the H 2 /2 H + interconversion from pH 0 to 9, with catalytic preference for H 2 oxidation at all pH values. The high activity of the complex over a wide pH range allows us to integrate this bio-inspired nanomaterial either in an enzymatic fuel cell together with a multicopper oxidase at the cathode, or in a proton exchange membrane fuel cell (PEMFC) using Pt/C at the cathode. The Ni-based PEMFC reaches 14 mW cm -2 , only six-times-less as compared to full-Pt conventional PEMFC. The Pt-free enzyme-based fuel cell delivers ≈2 mW cm -2 , a new efficiency record for a hydrogen biofuel cell with base metal catalysts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Experimental study of surface pattern effects on the propulsive performance and wake of a bio-inspired pitching panel

    Science.gov (United States)

    King, Justin; Kumar, Rajeev; Green, Melissa

    2016-11-01

    Force measurements and stereoscopic particle image velocimetry (PIV) were used to characterize the propulsive performance and wake structure of rigid, bio-inspired trapezoidal pitching panels. In the literature, it has been demonstrated that quantities such as thrust coefficient and propulsive efficiency are affected by changes in the surface characteristics of a pitching panel or foil. More specifically, the variation of surface pattern produces significant changes in wake structure and dynamics, especially in the distribution of vorticity in the wake. Force measurements and PIV data were collected for multiple surface patterns chosen to mimic fish surface morphology over a Strouhal number range of 0.17 to 0.56. Performance quantities are compared with the three-dimensional vortex wake structure for both the patterned and smooth panels to determine the nature and magnitude of surface pattern effects in terms of thrust produced, drag reduced, and wake vortices reshaped and reorganized. This work was supported by the Office of Naval Research under ONR Award No. N00014-14-1-0418.

  4. Hyper-morphology : Experimentations with bio-inspired design processes for adaptive spatial re-use

    NARCIS (Netherlands)

    Chang, J.R.

    2014-01-01

    This article is a newer version of a paper originally published in the eCAADe 2013 Conference Proceedings Computation & Performance. Hyper-Morphology is an on-going research outlining a bottom-up evolutionary design process based on autonomous cellular building components. The research interfaces

  5. Modeling and additive manufacturing of bio-inspired composites with tunable fracture mechanical properties.

    Science.gov (United States)

    Dimas, Leon S; Buehler, Markus J

    2014-07-07

    Flaws, imperfections and cracks are ubiquitous in material systems and are commonly the catalysts of catastrophic material failure. As stresses and strains tend to concentrate around cracks and imperfections, structures tend to fail far before large regions of material have ever been subjected to significant loading. Therefore, a major challenge in material design is to engineer systems that perform on par with pristine structures despite the presence of imperfections. In this work we integrate knowledge of biological systems with computational modeling and state of the art additive manufacturing to synthesize advanced composites with tunable fracture mechanical properties. Supported by extensive mesoscale computer simulations, we demonstrate the design and manufacturing of composites that exhibit deformation mechanisms characteristic of pristine systems, featuring flaw-tolerant properties. We analyze the results by directly comparing strain fields for the synthesized composites, obtained through digital image correlation (DIC), and the computationally tested composites. Moreover, we plot Ashby diagrams for the range of simulated and experimental composites. Our findings show good agreement between simulation and experiment, confirming that the proposed mechanisms have a significant potential for vastly improving the fracture response of composite materials. We elucidate the role of stiffness ratio variations of composite constituents as an important feature in determining the composite properties. Moreover, our work validates the predictive ability of our models, presenting them as useful tools for guiding further material design. This work enables the tailored design and manufacturing of composites assembled from inferior building blocks, that obtain optimal combinations of stiffness and toughness.

  6. Bio-inspired design of geometrically interlocked 3D printed joints

    Science.gov (United States)

    Kumar, S.; Oliva, Noel; Kumar's Lab Team

    The morphology of the adhesive-adherend interface significantly affects the mechanical behavior of adhesive joints. As seen in some biocomposites like human skull, or the nacre of some bivalve molluscs' shells, a geometrically interlocking architecture of interfaces creates toughening and strengthening mechanisms enhancing the mechanical properties of the joint. In an attempt to characterize this mechanical interlocking mechanism, this study is focused on computational and experimental investigation of a single-lap joint with a very simple geometrically interlocked interface design in which both adherends have a square waveform configuration of the joining surfaces. This square waveform configuration contains a positive and a negative rectangular teeth per cycle in such a way that the joint is symmetric about the mid-bondlength. Both physical tests performed on 3D printed prototypes of joints and computational results indicate that the joints with square waveform design have higher strength and damage tolerance than those of joints with flat interface. In order to identify an optimal design configuration of this interface, a systematic parametric study is conducted by varying the geometric and material properties of the non-flat interface. This work was supported by Lockheed Martin (Award No: 12NZZ1).

  7. Performance assessment of bio-inspired systems: flow sensing MEMS hairs

    International Nuclear Information System (INIS)

    Droogendijk, H; Krijnen, G J M; Casas, J; Steinmann, T

    2015-01-01

    Despite vigorous growth in biomimetic design, the performance of man-made devices relative to their natural templates is still seldom quantified, a procedure which would however significantly increase the rigour of the biomimetic approach. We applied the ubiquitous engineering concept of a figure of merit (FoM) to MEMS flow sensors inspired by cricket filiform hairs. A well known mechanical model of a hair is refined and tailored to this task. Five criteria of varying importance in the biological and engineering fields are computed: responsivity, power transfer, power efficiency, response time and detection threshold. We selected the metrics response time and detection threshold for building the FoM to capture the performance in a single number. Crickets outperform actual MEMS on all criteria for a large range of flow frequencies. Our approach enables us to propose several improvements for MEMS hair-sensor design. (paper)

  8. Real-time object tracking based on scale-invariant features employing bio-inspired hardware.

    Science.gov (United States)

    Yasukawa, Shinsuke; Okuno, Hirotsugu; Ishii, Kazuo; Yagi, Tetsuya

    2016-09-01

    We developed a vision sensor system that performs a scale-invariant feature transform (SIFT) in real time. To apply the SIFT algorithm efficiently, we focus on a two-fold process performed by the visual system: whole-image parallel filtering and frequency-band parallel processing. The vision sensor system comprises an active pixel sensor, a metal-oxide semiconductor (MOS)-based resistive network, a field-programmable gate array (FPGA), and a digital computer. We employed the MOS-based resistive network for instantaneous spatial filtering and a configurable filter size. The FPGA is used to pipeline process the frequency-band signals. The proposed system was evaluated by tracking the feature points detected on an object in a video. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Time-recovering PCI-AER interface for bio-inspired spiking systems

    Science.gov (United States)

    Paz-Vicente, R.; Linares-Barranco, A.; Cascado, D.; Vicente, S.; Jimenez, G.; Civit, A.

    2005-06-01

    Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows for real-time virtual massive connectivity between huge number neurons located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate 'events' according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. When building multi-chip muti-layered AER systems it is absolutely necessary to have a computer interface that allows (a) to read AER interchip traffic into the computer and visualize it on screen, and (b) inject a sequence of events at some point of the AER structure. This is necessary for testing and debugging complex AER systems. This paper presents a PCI to AER interface, that dispatches a sequence of events received from the PCI bus with embedded timing information to establish when each event will be delivered. A set of specialized states machines has been introduced to recovery the possible time delays introduced by the asynchronous AER bus. On the input channel, the interface capture events assigning a timestamp and delivers them through the PCI bus to MATLAB applications. It has been implemented in real time hardware using VHDL and it has been tested in a PCI-AER board, developed by authors, that includes a Spartan II 200 FPGA. The demonstration hardware is currently capable to send and receive events at a peak rate of 8,3 Mev/sec, and a typical rate of 1 Mev/sec.

  10. Mobile Robots for Localizing Gas Emission Sources on Landfill Sites: Is Bio-Inspiration the Way to Go?

    Directory of Open Access Journals (Sweden)

    Victor eHernandez Bennetts

    2012-01-01

    Full Text Available Roboticists often take inspiration from animals for designing sensors, actuators or algorithms that control the behaviour of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odour plume. In particular the task of tracking an odour plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behaviour of moths, dungbeetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro drone in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is at the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behaviour of animals, can be usefully translated into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically-inspired algorithms.

  11. Mobile robots for localizing gas emission sources on landfill sites: is bio-inspiration the way to go?

    Science.gov (United States)

    Hernandez Bennetts, Victor; Lilienthal, Achim J; Neumann, Patrick P; Trincavelli, Marco

    2011-01-01

    Roboticists often take inspiration from animals for designing sensors, actuators, or algorithms that control the behavior of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odor plume. In particular the task of tracking an odor plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behavior of moths, dung beetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro-drone) in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behavior of animals, can be usefully "translated" into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically inspired algorithms.

  12. Adaptive Bio-Inspired Wireless Network Routing for Planetary Surface Exploration

    Science.gov (United States)

    Alena, Richard I.; Lee, Charles

    2004-01-01

    Wireless mobile networks suffer connectivity loss when used in a terrain that has hills, and valleys when line of sight is interrupted or range is exceeded. To resolve this problem and achieve acceptable network performance, we have designed an adaptive, configurable, hybrid system to automatically route network packets along the best path between multiple geographically dispersed modules. This is very useful in planetary surface exploration, especially for ad-hoc mobile networks, where computational devices take an active part in creating a network infrastructure, and can actually be used to route data dynamically and even store data for later transmission between networks. Using inspiration from biological systems, this research proposes to use ant trail algorithms with multi-layered information maps (topographic maps, RF coverage maps) to determine the best route through ad-hoc network at real time. The determination of best route is a complex one, and requires research into the appropriate metrics, best method to identify the best path, optimizing traffic capacity, network performance, reliability, processing capabilities and cost. Real ants are capable of finding the shortest path from their nest to a food source without visual sensing through the use of pheromones. They are also able to adapt to changes in the environment using subtle clues. To use ant trail algorithms, we need to define the probability function. The artificial ant is, in this case, a software agent that moves from node to node on a network graph. The function to calculate the fitness (evaluate the better path) includes: length of the network edge, the coverage index, topology graph index, and pheromone trail left behind by other ant agents. Each agent modifies the environment in two different ways: 1) Local trail updating: As the ant moves between nodes it updates the amount of pheromone on the edge; and 2) Global trail updating: When all ants have completed a tour the ant that found the

  13. Bio-inspired digital signal processing for fast radionuclide mixture identification

    Science.gov (United States)

    Thevenin, M.; Bichler, O.; Thiam, C.; Bobin, C.; Lourenço, V.

    2015-05-01

    Countries are trying to equip their public transportation infrastructure with fixed radiation portals and detectors to detect radiological threat. Current works usually focus on neutron detection, which could be useless in the case of dirty bomb that would not use fissile material. Another approach, such as gamma dose rate variation monitoring is a good indication of the presence of radionuclide. However, some legitimate products emit large quantities of natural gamma rays; environment also emits gamma rays naturally. They can lead to false detections. Moreover, such radio-activity could be used to hide a threat such as material to make a dirty bomb. Consequently, radionuclide identification is a requirement and is traditionally performed by gamma spectrometry using unique spectral signature of each radionuclide. These approaches require high-resolution detectors, sufficient integration time to get enough statistics and large computing capacities for data analysis. High-resolution detectors are fragile and costly, making them bad candidates for large scale homeland security applications. Plastic scintillator and NaI detectors fit with such applications but their resolution makes identification difficult, especially radionuclides mixes. This paper proposes an original signal processing strategy based on artificial spiking neural networks to enable fast radionuclide identification at low count rate and for mixture. It presents results obtained for different challenging mixtures of radionuclides using a NaI scintillator. Results show that a correct identification is performed with less than hundred counts and no false identification is reported, enabling quick identification of a moving threat in a public transportation. Further work will focus on using plastic scintillators.

  14. Flow Interactions of Two- and Three-Dimensional Networked Bio-Inspired Control Elements in an In-Line Arrangement.

    Science.gov (United States)

    Kurt, Melike; Moored, Keith

    2018-04-19

    -dimensions. These results can aid in the design of networked bio-inspired control elements that through integrated sensing can synchronize to three-dimensional flow interactions. © 2018 IOP Publishing Ltd.

  15. Improvement to the pattern of control rods of the equilibrium cycle of 18 months for the CLV using bio-inspired algorithms

    International Nuclear Information System (INIS)

    Perusquia, R.; Ortiz, J.J.; Montes, J.L.

    2003-01-01

    Nowadays in the National Institute of Nuclear Research are carried out studies with some bio-inspired optimization techniques to improve the performance of the fuel cycles of the boiling water reactors of the Laguna Verde power plant (CLV). In the present work two bio-inspired techniques were applied with the purpose of improving the performance of a balance cycle of 18 months developed for the CLV: genetic algorithms (AG) and systems based on ants colonies (SCH). The design of the reference cycle it represents in several aspects an optimal cycle proposed starting from the experience of several operation decades with the boiling water reactors (BWR initials for Boiling Water Reactor) in the world. To try to improve their performance is beforehand a difficult challenge and it puts on test the feasibility of the optimization methods in the reloads design. The study of the bio-inspired techniques was centered exclusively on the obtaining of the control rod patterns (PBC) trying to overcome the capacity factor reached in the design of the reference cycle. It was fixed the cycle length such that the decrease of the coast down period would represent an increase of the capacity factor of the cycle; so that, it diminishes the annual cost associated with the capital cost of the plant. As consequence of the study, was found that the algorithm based on the ants colonies reaches to diminish the coast down period in five and half days respect to the original balance cycle, what represents an annual saving of $US 74,000. Since the original cycle was optimized, the above-mentioned, shows the ability of the SCH for the optimization of the cycle design. With the AG it was reach to approach to the original balance cycle with a coast down period greater in seven days estimating an annual penalization of $US 130,000. (Author)

  16. Bio-inspired feedback-circuit implementation of discrete, free energy optimizing, winner-take-all computations.

    Science.gov (United States)

    Genewein, Tim; Braun, Daniel A

    2016-06-01

    Bayesian inference and bounded rational decision-making require the accumulation of evidence or utility, respectively, to transform a prior belief or strategy into a posterior probability distribution over hypotheses or actions. Crucially, this process cannot be simply realized by independent integrators, since the different hypotheses and actions also compete with each other. In continuous time, this competitive integration process can be described by a special case of the replicator equation. Here we investigate simple analog electric circuits that implement the underlying differential equation under the constraint that we only permit a limited set of building blocks that we regard as biologically interpretable, such as capacitors, resistors, voltage-dependent conductances and voltage- or current-controlled current and voltage sources. The appeal of these circuits is that they intrinsically perform normalization without requiring an explicit divisive normalization. However, even in idealized simulations, we find that these circuits are very sensitive to internal noise as they accumulate error over time. We discuss in how far neural circuits could implement these operations that might provide a generic competitive principle underlying both perception and action.

  17. Bio-inspired green synthesis of Fe{sub 3}O{sub 4} spherical magnetic nanoparticles using Syzygium cumini seed extract

    Energy Technology Data Exchange (ETDEWEB)

    Venkateswarlu, Sada; Natesh Kumar, B.; Prasad, C.H.; Venkateswarlu, P.; Jyothi, N.V.V., E-mail: nvvjyothi01@gmail.com

    2014-09-15

    A novel and bio-inspired Fe{sub 3}O{sub 4} spherical magnetic nanoparticles (SMNPs) were synthesized using Syzygium cumini (S. cumini) seed extract, which is a non-toxic ecofriendly fruit waste material. S. cumini seed extract acts as a green solvent, reducing and capping agent in which sodium acetate acts as electrostatic stabilizing agent. The green synthesized nanoparticles were characterized with the help of various techniques such as X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), Energy-dispersive spectroscopy (EDS), Vibrating sample magnetometer (VSM), FTIR spectroscopy and nitrogen adsorption and desorption analysis techniques. The XRD study divulged that the synthesized SMNPs have inverse spinel cubic structure. The hysteresis loop of Fe{sub 3}O{sub 4} nanoparticles shows an excellent ferromagnetic behavior with saturation magnetization value of 13.6 emu/g.

  18. Light and colour as analytical detection tools: a journey into the periodic table using polyamines to bio-inspired systems as chemosensors.

    Science.gov (United States)

    Lodeiro, Carlos; Capelo, José Luis; Mejuto, Juan Carlos; Oliveira, Elisabete; Santos, Hugo M; Pedras, Bruno; Nuñez, Cristina

    2010-08-01

    This critical review describes some developments on the chemistry of fluorescent and colorimetric molecular probes or chemosensors, based on polyamines and associated compounds having oxygen and/or sulfur as donor atoms. The reported systems are essentially based on some selected published work in this field in the last five years, and in the work developed by the authors from 2000 onwards. Some interesting properties beyond sensing molecules, ions or/and cations by fluorescence, colorimetry as well as by MALDI-TOF MS spectrometry can arise from these systems. A short brief on different examples activated by PET (photoinduced electron transfer), ICT (internal charge transfer) and EET (electronic energy transfer) phenomena will be provided. Finally the introduction of bio-inspired compounds derived from emissive amino acid or short peptide systems and nanoparticle devices to detect metal ions will be reviewed (202 references).

  19. Characterization of anthocyanin based dye-sensitized organic solar cells (DSSC) and modifications based on bio-inspired ion mobility improvements

    Science.gov (United States)

    Mawyin, Jose Amador

    The worldwide electrical energy consumption will increase from currently 10 terawatts to 30 terawatts by 2050. To decrease the current atmospheric CO2 would require our civilization to develop a 20 terawatts non-greenhouse emitting (renewable) electrical power generation capability. Solar photovoltaic electric power generation is thought to be a major component of proposed renewable energy-based economy. One approach to less costly, easily manufactured solar cells is the Dye-sensitized solar cells (DSSC) introduced by Greatzel and others. This dissertation describes the work focused on improving the performance of DSSC type solar cells. In particular parameters affecting dye-sensitized solar cells (DSSC) based on anthocyanin pigments extracted from California blackberries (Rubus ursinus) and bio-inspired modifications were analyzed and solar cell designs optimized. Using off-the-shelf materials DSSC were constructed and tested using a custom made solar spectrum simulator and photoelectric property characterization. This equipment facilitated the taking of automated I-V curve plots and the experimental determination of parameters such as open circuit voltage (V OC), short circuit current (JSC), fill factor (FF), etc. This equipment was used to probe the effect of various modifications such as changes in the annealing time and composition of the of the electrode counter-electrode. Solar cell optimization schemes included novel schemes such as solar spectrum manipulation to increase the percentage of the solar spectrum capable of generating power in the DSSC. Solar manipulation included light scattering and photon upconversion. Techniques examined here focused on affordable materials such as silica nanoparticles embedded inside a TiO2 matrix. Such materials were examined for controlled scattering of visible light and optimize light trapping within the matrix as well as a means to achieve photon up-energy-conversion using the Raman effect in silica nano-particles (due

  20. The Difference Se Makes: A Bio-Inspired Dppf-Supported Nickel Selenolate Complex Boosts Dihydrogen Evolution with High Oxygen Tolerance.

    Science.gov (United States)

    Pan, Zhong-Hua; Tao, Yun-Wen; He, Quan-Feng; Wu, Qiao-Yu; Cheng, Li-Ping; Wei, Zhan-Hua; Wu, Ji-Huai; Lin, Jin-Qing; Sun, Di; Zhang, Qi-Chun; Tian, Dan; Luo, Geng-Geng

    2018-06-12

    Inspired by the metal active sites of [NiFeSe]-hydrogenases, a dppf-supported nickel(II) selenolate complex (dppf=1,1'-bis(diphenylphosphino)ferrocene) shows high catalytic activity for electrochemical proton reduction with a remarkable enzyme-like H 2 evolution turnover frequency (TOF) of 7838 s -1 under an Ar atmosphere, which markedly surpasses the activity of a dppf-supported nickel(II) thiolate analogue with a low TOF of 600 s -1 . A combined study of electrochemical experiments and DFT calculations shed light on the catalytic process, suggesting that selenium atom as a bio-inspired proton relay plays a key role in proton exchange and enhancing catalytic activity of H 2 production. For the first time, this type of Ni selenolate-containing electrocatalyst displays a high degree of O 2 and H 2 tolerance. Our results should encourage the development of the design of highly efficient oxygen-tolerant Ni selenolate molecular catalysts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Laser-Sintered Constructs with Bio-inspired Porosity and Surface Micro/Nano-Roughness Enhance Mesenchymal Stem Cell Differentiation and Matrix Mineralization In Vitro.

    Science.gov (United States)

    Cheng, Alice; Cohen, David J; Boyan, Barbara D; Schwartz, Zvi

    2016-12-01

    Direct metal laser sintering can produce porous Ti-6Al-4V orthopedic and dental implants. The process requires reduced resources and time and can provide greater structural control than machine manufacturing. Implants in bone are colonized by mesenchymal stem cells (MSCs), which can differentiate into osteoblasts and contribute to osseointegration. This study examined osteoblast differentiation and matrix mineralization of human MSCs cultured on laser-sintered Ti-6Al-4V constructs with varying porosity and at different time scales. 2D solid disks and low, medium and high porosity (LP, MP, and HP) 3D constructs based on a human trabecular bone template were laser sintered from Ti-6Al-4V powder and further processed to have micro- and nanoscale roughness. hMSCs exhibited greater osteoblastic differentiation and local factor production on all 3D porous constructs compared to 2D surfaces, which was sustained for 9 days without use of exogenous factors. hMSCs cultured for 8 weeks on MP constructs in osteogenic medium (OM), OM supplemented with BMP2 or collagen-coated MP constructs in OM exhibited bone-like extracellular matrix mineralization. Use of bio-inspired porosity for the 3D architecture of additively manufactured Ti-6Al-4V enhanced osteogenic differentiation of hMSCs beyond surface roughness alone. This study suggests that a 3D architecture may enhance the osseointegration of orthopedic and dental implants in vivo.

  2. Bio-inspired CO2 reduction by a rhenium tricarbonyl bipyridine-based catalyst appended to amino acids and peptidic platforms: incorporating proton relays and hydrogen-bonding functional groups.

    Science.gov (United States)

    Chabolla, S A; Machan, C W; Yin, J; Dellamary, E A; Sahu, S; Gianneschi, N C; Gilson, M K; Tezcan, F A; Kubiak, C P

    2017-06-02

    Herein, we report a new approach to bio-inspired catalyst design. The molecular catalyst employed in these studies is based on the robust and selective Re(bpy)(CO) 3 Cl-type (bpy = 2,2'-bipyridine) homogeneous catalysts, which have been extensively studied for their ability to reduce CO 2 electrochemically or photochemically in the presence of a photosensitizer. These catalysts can be highly active photocatalysts in their own right. In this work, the bipyridine ligand was modified with amino acids and synthetic peptides. These results build on earlier findings wherein the bipyridine ligand was functionalized with amide groups to promote dimer formation and CO 2 reduction by an alternate bimolecular mechanism at lower overpotential (ca. 250 mV) than the more commonly observed unimolecular process. The bio-inspired catalysts were designed to allow for the incorporation of proton relays to support reduction of CO 2 to CO and H 2 O. The coupling of amino acids tyrosine and phenylalanine led to the formation of two structurally similar Re catalyst/peptide catalysts for comparison of proton transport during catalysis. This article reports the synthesis and characterization of novel catalyst/peptide hybrids by molecular dynamics (MD simulations of structural dynamics), NMR studies of solution phase structures, and electrochemical studies to measure the activities of new bio-inspired catalysts in the reduction of CO 2.

  3. Binary Synergy Strengthening and Toughening of Bio-Inspired Nacre-like Graphene Oxide/Sodium Alginate Composite Paper.

    Science.gov (United States)

    Chen, Ke; Shi, Bin; Yue, Yonghai; Qi, Juanjuan; Guo, Lin

    2015-08-25

    A crucial requirement for most engineering materials is the excellent balance of strength and toughness. By mimicking the hybrid hierarchical structure in nacre, a kind of nacre-like paper based on binary hybrid graphene oxide (GO)/sodium alginate (SA) building blocks has been successfully fabricated. Systematic evaluation for the mechanical property in different (dry/wet) environment/after thermal annealing shows a perfect combination of high strength and toughness. Both of the parameters are nearly many-times higher than those of similar materials because of the synergistic strengthening/toughening enhancement from the binary GO/SA hybrids. The successful fabrication route offers an excellent approach to design advanced strong integrated nacre-like composite materials, which can be applied in tissue engineering, protection, aerospace, and permeable membranes for separation and delivery.

  4. Bio-inspired enhancement of friction and adhesion at the polydimethylsiloxane-intestine interface and biocompatibility characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongyu, E-mail: zhanghyu@tsinghua.edu.cn [State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Wang, Yi [State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Vasilescu, Steven [School of Mathematics and Physical Science, Faculty of Science, University of Technology Sydney, New South Wales 2007 (Australia); Gu, Zhibin [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); Sun, Tao [State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

    2017-05-01

    An active navigation of self-propelled miniaturized robot along the intestinal tract without injuring the soft tissue remains a challenge as yet. Particularly in this case an effective control of the interfacial friction and adhesion between the material used and the soft tissue is crucial. In the present study, we investigated the frictional and adhesive properties between polydimethylsiloxane (PDMS, microscopically patterned with micro-pillar arrays and non-patterned with a flat surface) and rabbit small intestinal tract using a universal material tester. The friction coefficient-time plot and adhesive force-time plot were recorded during the friction test (sliding speed: 0.25 mm/s; normal loading: 0.4 N) and adhesion test (preloading: 0.5 N; hoisting speed: 2.5 × 10{sup −3} mm/s). In addition, biocompatibility of the PDMS samples was characterized in terms of cell morphology (scanning electron microscope) and cell cytotoxicity (alamarBlue assay) using human vascular endothelial cells (HUVECs). The results demonstrated that the interfacial friction (0.27 vs 0.19) and adhesion (34.9 mN vs 26.7 mN) were greatly increased using microscopically patterned PDMS, in comparison with non-patterned PDMS. HUVECs adhered to and proliferated on non-patterned/microscopically patterned PDMS very well, with a relative cell viability of about 90% following seeding at 1 d, 3 d, and 5 d. The favorable enhancement of the frictional and adhesive properties, along with the excellent biocompatibility of the microscopically patterned PDMS, makes it a propitious choice for clinical application of self-propelled miniaturized robots. - Highlights: • Micro-pillars enhanced friction and adhesion between PDMS and intestinal tract. • Micro-patterned PDMS showed good cell morphology and cytotoxicity using HUVECs. • Micro-pattern technology may be applied in self-propelled miniaturized robot.

  5. Bio-inspired enhancement of friction and adhesion at the polydimethylsiloxane-intestine interface and biocompatibility characterization

    International Nuclear Information System (INIS)

    Zhang, Hongyu; Wang, Yi; Vasilescu, Steven; Gu, Zhibin; Sun, Tao

    2017-01-01

    An active navigation of self-propelled miniaturized robot along the intestinal tract without injuring the soft tissue remains a challenge as yet. Particularly in this case an effective control of the interfacial friction and adhesion between the material used and the soft tissue is crucial. In the present study, we investigated the frictional and adhesive properties between polydimethylsiloxane (PDMS, microscopically patterned with micro-pillar arrays and non-patterned with a flat surface) and rabbit small intestinal tract using a universal material tester. The friction coefficient-time plot and adhesive force-time plot were recorded during the friction test (sliding speed: 0.25 mm/s; normal loading: 0.4 N) and adhesion test (preloading: 0.5 N; hoisting speed: 2.5 × 10 −3 mm/s). In addition, biocompatibility of the PDMS samples was characterized in terms of cell morphology (scanning electron microscope) and cell cytotoxicity (alamarBlue assay) using human vascular endothelial cells (HUVECs). The results demonstrated that the interfacial friction (0.27 vs 0.19) and adhesion (34.9 mN vs 26.7 mN) were greatly increased using microscopically patterned PDMS, in comparison with non-patterned PDMS. HUVECs adhered to and proliferated on non-patterned/microscopically patterned PDMS very well, with a relative cell viability of about 90% following seeding at 1 d, 3 d, and 5 d. The favorable enhancement of the frictional and adhesive properties, along with the excellent biocompatibility of the microscopically patterned PDMS, makes it a propitious choice for clinical application of self-propelled miniaturized robots. - Highlights: • Micro-pillars enhanced friction and adhesion between PDMS and intestinal tract. • Micro-patterned PDMS showed good cell morphology and cytotoxicity using HUVECs. • Micro-pattern technology may be applied in self-propelled miniaturized robot.

  6. Bio-inspired configurable multiscale extracellular matrix-like structures for functional alignment and guided orientation of cells.

    Science.gov (United States)

    Bae, Won-Gyu; Kim, Jangho; Choung, Yun-Hoon; Chung, Yesol; Suh, Kahp Y; Pang, Changhyun; Chung, Jong Hoon; Jeong, Hoon Eui

    2015-11-01

    Inspired by the hierarchically organized protein fibers in extracellular matrix (ECM) as well as the physiological importance of multiscale topography, we developed a simple but robust method for the design and manipulation of precisely controllable multiscale hierarchical structures using capillary force lithography in combination with an original wrinkling technique. In this study, based on our proposed fabrication technology, we approached a conceptual platform that can mimic the hierarchically multiscale topographical and orientation cues of the ECM for controlling cell structure and function. We patterned the polyurethane acrylate-based nanotopography with various orientations on the microgrooves, which could provide multiscale topography signals of ECM to control single and multicellular morphology and orientation with precision. Using our platforms, we found that the structures and orientations of fibroblast cells were greatly influenced by the nanotopography, rather than the microtopography. We also proposed a new approach that enables the generation of native ECM having nanofibers in specific three-dimensional (3D) configurations by culturing fibroblast cells on the multiscale substrata. We suggest that our methodology could be used as efficient strategies for the design and manipulation of various functional platforms, including well-defined 3D tissue structures for advanced regenerative medicine applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Design and operation of a bio-inspired micropump based on blood-sucking mechanism of mosquitoes

    Science.gov (United States)

    Leu, Tzong-Shyng; Kao, Ruei-Hung

    2018-05-01

    The study is to develop a novel bionic micropump, mimicking blood-suck mechanism of mosquitos with a similar efficiency of 36%. The micropump is produced by using micro-electro-mechanical system (MEMS) technology, PDMS (polydimethylsiloxane) to fabricate the microchannel, and an actuator membrane made by Fe-PDMS. It employs an Nd-FeB permanent magnet and PZT to actuate the Fe-PDMS membrane for generating flow rate. A lumped model theory and the Taguchi method are used for numerical simulation of pulsating flow in the micropump. Also focused is to change the size of mosquito mouth for identifying the best waveform for the transient flow processes. Based on computational results of channel size and the Taguchi method, an optimization actuation waveform is identified. The maximum pumping flow rate is 23.5 μL/min and the efficiency is 86%. The power density of micropump is about 8 times of that produced by mosquito’s suction. In addition to using theoretical design of the channel size, also combine with Taguchi method and asymmetric actuation to find the optimization actuation waveform, the experimental result shows the maximum pumping flowrate is 23.5 μL/min and efficiency is 86%, moreover, the power density of micropump is 8 times higher than mosquito’s.

  8. Lightweight mechanical amplifiers for rolled dielectric elastomer actuators and their integration with bio-inspired wing flappers

    International Nuclear Information System (INIS)

    Lau, Gih-Keong; Lim, Hoong-Ta; Teo, Jing-Ying; Chin, Yao-Wei

    2014-01-01

    Dielectric elastomer actuators (DEAs) are attractive for use in bio-inspired flapping-wing robots because they have high work density (specific energy) and can produce a large actuation strain. Although the active membrane of a dielectric elastomer is lightweight, the support structure that pre-tensions the elastomeric membrane is massive and it lowers the overall work density. If the DEA is to be used successfully to drive flapping-wing robots, its support structure must be as lightweight as possible. In this work, we designed, analysed, and developed a lightweight shell using a cross-ply laminate of carbon fibre reinforced polymer (CFRP) to pre-strain a rolled DEA. The CFRP shell was shown to weigh 24.3% of the total mass for the whole DEA assembly, while providing up to 35.0% axial pre-strain to a rolled DEA (BJB-5005 silicone rubber). This DEA assembly using the CFRP shell achieved 30.9% of the theoretical work density for a BJB-TC5005 membrane at 33.5 MV m −1 . In comparison, spring rolls with a massive spring core were reported with overall work density merely 10–20% of the maximum value. Furthermore, this CFRP shell can amplify an axial DEA stroke into a larger transverse shell deformation. With these deformation characteristics, this CFRP shell and a rolled DEA were successfully integrated with an insect-inspired thoracic mechanism and they were shown to be feasible to drive it for a flapping wing. (paper)

  9. Bio-inspired control of joint torque and knee stiffness in a robotic lower limb exoskeleton using a central pattern generator.

    Science.gov (United States)

    Schrade, Stefan O; Nager, Yannik; Wu, Amy R; Gassert, Roger; Ijspeert, Auke

    2017-07-01

    Robotic lower limb exoskeletons are becoming increasingly popular in therapy and recreational use. However, most exoskeletons are still rather limited in their locomotion speed and the activities of daily live they can perform. Furthermore, they typically do not allow for a dynamic adaptation to the environment, as they are often controlled with predefined reference trajectories. Inspired by human leg stiffness modulation during walking, variable stiffness actuators increase flexibility without the need for more complex controllers. Actuation with adaptable stiffness is inspired by the human leg stiffness modulation during walking. However, this actuation principle also introduces the stiffness setpoint as an additional degree of freedom that needs to be coordinated with the joint trajectories. As a potential solution to this issue a bio-inspired controller based on a central pattern generator (CPG) is presented in this work. It generates coordinated joint torques and knee stiffness modulations to produce flexible and dynamic gait patterns for an exoskeleton with variable knee stiffness actuation. The CPG controller is evaluated and optimized in simulation using a model of the exoskeleton. The CPG controller produced stable and smooth gait for walking speeds from 0.4 m/s up to 1.57 m/s with a torso stabilizing force that simulated the use of crutches, which are commonly needed by exoskeleton users. Through the CPG, the knee stiffness intrinsically adapted to the frequency and phase of the gait, when the speed was changed. Additionally, it adjusted to changes in the environment in the form of uneven terrain by reacting to ground contact forces. This could allow future exoskeletons to be more adaptive to various environments, thus making ambulation more robust.

  10. On the synthesis of a bio-inspired dual-cellular fluidic flexible matrix composite adaptive structure based on a non-dimensional dynamics model

    International Nuclear Information System (INIS)

    Li, Suyi; Wang, K W

    2013-01-01

    A recent study investigated the dynamic characteristics of an adaptive structure concept featuring dual fluidic flexible matrix composite (F 2 MC) cells inspired by the configuration of plant cells and cell walls. This novel bio-inspired system consists of two F 2 MC cells with different fiber angles connected through internal fluid circuits. It was discovered that the dual F 2 MC cellular structure can be characterized as a two degree of freedom damped mass–spring oscillator, and can be utilized as a vibration absorber or an enhanced actuator under different operation conditions. These results demonstrated that the concept is promising and further investigations are needed to develop methodologies for synthesizing future multi-cellular F 2 MC structural systems. While interesting, the previous study focused on specific case studies and analysis. That is, the outcome did not provide insight that could be generalized, or tools for synthesizing a multiple F 2 MC cellular structure. This paper attempts to address this important issue by developing a non-dimensional dynamic model, which reveals good physical insights as well as identifying crucial constitutive parameters for F 2 MC cellular design. Working with these parameters, rather than physical variables, can greatly simplify the mathematics involved in the study. A synthesis tool is then developed for the dual-cellular structure, and it is found that for each set of achievable target poles and zero, there exist multiple F 2 MC cellular designs, forming a design space. The presented physical insights and synthesis tool for the dual-cellular structure will be the building blocks for future investigation on cellular structures with a larger number of cells. (paper)

  11. Effect of pre-tension on the peeling behavior of a bio-inspired nano-film and a hierarchical adhesive structure

    Science.gov (United States)

    Peng, Zhilong; Chen, Shaohua

    2012-10-01

    Inspired by the reversible adhesion behaviors of geckos, the effects of pre-tension in a bio-inspired nano-film and a hierarchical structure on adhesion are studied theoretically. In the case with a uniformly distributing pre-tension in a spatula-like nano-film under peeling, a closed-form solution to a critical peeling angle is derived, below or above which the peel-off force is enhanced or reduced, respectively, compared with the case without pre-tension. The effects of a non-uniformly distributing pre-tension on adhesion are further investigated for both a spatula-like nano-film and a hierarchical structure-like gecko's seta. Compared with the case without pre-tension, the pre-tension, no matter uniform or non-uniform, can increase the adhesion force not only for the spatula-like nano-film but also for the hierarchical structure at a small peeling angle, while decrease it at a relatively large peeling angle. Furthermore, if the pre-tension is large enough, the effective adhesion energy of a hierarchical structure tends to vanish at a critical peeling angle, which results in spontaneous detachment of the hierarchical structure from the substrate. The present theoretical predictions can not only give some explanations on the existing experimental observation that gecko's seta always detaches at a specific angle and no apparent adhesion force can be detected above the critical angle but also provide a deep understanding for the reversible adhesion mechanism of geckos and be helpful to the design of biomimetic reversible adhesives.

  12. Efficient computation in adaptive artificial spiking neural networks

    NARCIS (Netherlands)

    D. Zambrano (Davide); R.B.P. Nusselder (Roeland); H.S. Scholte; S.M. Bohte (Sander)

    2017-01-01

    textabstractArtificial Neural Networks (ANNs) are bio-inspired models of neural computation that have proven highly effective. Still, ANNs lack a natural notion of time, and neural units in ANNs exchange analog values in a frame-based manner, a computationally and energetically inefficient form of

  13. Bio-Inspired Controllable Adhesive

    Science.gov (United States)

    2008-12-01

    pad of the tarsus – which act as a sort of hydraulic suspension. The lamellae contain rows of thin slender fibers , called setae, approximately 130 µm...in length and 20 µm in diameter (Hildebrand, 1988), Fig.1. The terminus of each seta branches into thousands of smaller fibers , or spatular stalks...ADHESION TESTING The structures were characterized (Northen et al., 2008) using a home-built adhesion test apparatus ( Basalt - II) with C. Greiner

  14. A bio-inspired zinc finger analogue anchored in 2D hexagonal meso-porous silica for room temperature CO_2 activation via a hydrogeno-carbonate route

    International Nuclear Information System (INIS)

    Doghri, Hanene; Baranova, Elena A.; Albela, Belen; Bonneviot, Laurent; Mongia Said-Zina

    2017-01-01

    Bio-inspired diethylenetriamine-zinc(II) complexes were anchored into the nano-pores of hexagonal meso-porous MCM41-like silicas targeting a carbamate free and low temperature CO_2 recycling process. A step-by-step approach was adopted to perform an in situ synthesis in order to mimic the zinc finger of carbonic anhydrases, the fastest family of enzymes. In the presence of a surface-masking pattern of TMA"+ ions, some silanol groups were capped using grafted trimethylsilyl functions, TMSgr, (gr for grafted). After removing the masking ions, a tridentate diethylenetriamine ligand was anchored using diethylenetriamine propyl-trimethoxysilane. The so-called DETA_a_n ligands (an for anchored) were partially mono-protonated using either cyclohexane or isopropanol as a solvent. Nonetheless, up to two thirds of them were metallated by Zn(II) ions, leading to the targeted anchored zinc finger mimic [Zn(DETAan)L]+(L = Cl or OH). CO_2 is then adsorbed at room temperature and in humid ambient air by the formation of an intermediate hydrogeno-carbonate-zinc complex. Specific IR signatures at 1330 and 1400 cm"-"1 together with characteristic C 1s and Zn 2p3/2 XPS binding energies at 286.4 and 1024.6 eV advocate for a rather symmetrical bidentate [η"2-CO_3] structural unit in the anchored complex [Zn(DETA_a_n)(η"2-HCO_3"*)]"+, where the Zn(II) ion is most likely penta-coordinated. The internal pH value varied by less than 0.5 depending on the metal reacting with the DETA_a_n ligand and its ability to generate HCO_3"-, due to the buffering effect of surface silanol and amino groups according to the level of protonation of the DETA moieties measured from the N 1s XPS spectra. In contrast to nitrate ions, chloride ions were found to inhibit the formation of hydrogeno-carbonate. (authors)

  15. Soft Tissue Biomechanical Modeling for Computer Assisted Surgery

    CERN Document Server

    2012-01-01

      This volume focuses on the biomechanical modeling of biological tissues in the context of Computer Assisted Surgery (CAS). More specifically, deformable soft tissues are addressed since they are the subject of the most recent developments in this field. The pioneering works on this CAS topic date from the 1980's, with applications in orthopaedics and biomechanical models of bones. More recently, however, biomechanical models of soft tissues have been proposed since most of the human body is made of soft organs that can be deformed by the surgical gesture. Such models are much more complicated to handle since the tissues can be subject to large deformations (non-linear geometrical framework) as well as complex stress/strain relationships (non-linear mechanical framework). Part 1 of the volume presents biomechanical models that have been developed in a CAS context and used during surgery. This is particularly new since most of the soft tissues models already proposed concern Computer Assisted Planning, with ...

  16. Tissue P Systems With Channel States Working in the Flat Maximally Parallel Way.

    Science.gov (United States)

    Song, Bosheng; Perez-Jimenez, Mario J; Paun, Gheorghe; Pan, Linqiang

    2016-10-01

    Tissue P systems with channel states are a class of bio-inspired parallel computational models, where rules are used in a sequential manner (on each channel, at most one rule can be used at each step). In this work, tissue P systems with channel states working in a flat maximally parallel way are considered, where at each step, on each channel, a maximal set of applicable rules that pass from a given state to a unique next state, is chosen and each rule in the set is applied once. The computational power of such P systems is investigated. Specifically, it is proved that tissue P systems with channel states and antiport rules of length two are able to compute Parikh sets of finite languages, and such P systems with one cell and noncooperative symport rules can compute at least all Parikh sets of matrix languages. Some Turing universality results are also provided. Moreover, the NP-complete problem SAT is solved by tissue P systems with channel states, cell division and noncooperative symport rules working in the flat maximally parallel way; nevertheless, if channel states are not used, then such P systems working in the flat maximally parallel way can solve only tractable problems. These results show that channel states provide a frontier of tractability between efficiency and non-efficiency in the framework of tissue P systems with cell division (assuming P ≠ NP ).

  17. Osteotomy simulation and soft tissue prediction using computer tomography scans

    International Nuclear Information System (INIS)

    Teschner, M.; Girod, S.; Girod, B.

    1999-01-01

    In this paper, a system is presented that can be used to simulate osteotomies of the skull and to estimate the resulting of tissue changes. Thus, the three-dimensional, photorealistic, postoperative appearance of a patient can be assessed. The system is based on a computer tomography scan and a photorealistic laser scan of the patient's face. In order to predict the postoperative appearance of a patient the soft tissue must follow the movement of the underlying bone. In this paper, a multi-layer soft tissue model is proposed that is based on springs. It incorporates features like skin turgor, gravity and sliding bone contact. The prediction of soft tissue changes due to bone realignments is computed using a very efficient and robust optimization method. The system can handle individual patient data sets and has been tested with several clinical cases. (author)

  18. Vascular tissue engineering by computer-aided laser micromachining.

    Science.gov (United States)

    Doraiswamy, Anand; Narayan, Roger J

    2010-04-28

    Many conventional technologies for fabricating tissue engineering scaffolds are not suitable for fabricating scaffolds with patient-specific attributes. For example, many conventional technologies for fabricating tissue engineering scaffolds do not provide control over overall scaffold geometry or over cell position within the scaffold. In this study, the use of computer-aided laser micromachining to create scaffolds for vascular tissue networks was investigated. Computer-aided laser micromachining was used to construct patterned surfaces in agarose or in silicon, which were used for differential adherence and growth of cells into vascular tissue networks. Concentric three-ring structures were fabricated on agarose hydrogel substrates, in which the inner ring contained human aortic endothelial cells, the middle ring contained HA587 human elastin and the outer ring contained human aortic vascular smooth muscle cells. Basement membrane matrix containing vascular endothelial growth factor and heparin was to promote proliferation of human aortic endothelial cells within the vascular tissue networks. Computer-aided laser micromachining provides a unique approach to fabricate small-diameter blood vessels for bypass surgery as well as other artificial tissues with complex geometries.

  19. Bone tissue engineering scaffolding: computer-aided scaffolding techniques.

    Science.gov (United States)

    Thavornyutikarn, Boonlom; Chantarapanich, Nattapon; Sitthiseripratip, Kriskrai; Thouas, George A; Chen, Qizhi

    Tissue engineering is essentially a technique for imitating nature. Natural tissues consist of three components: cells, signalling systems (e.g. growth factors) and extracellular matrix (ECM). The ECM forms a scaffold for its cells. Hence, the engineered tissue construct is an artificial scaffold populated with living cells and signalling molecules. A huge effort has been invested in bone tissue engineering, in which a highly porous scaffold plays a critical role in guiding bone and vascular tissue growth and regeneration in three dimensions. In the last two decades, numerous scaffolding techniques have been developed to fabricate highly interconnective, porous scaffolds for bone tissue engineering applications. This review provides an update on the progress of foaming technology of biomaterials, with a special attention being focused on computer-aided manufacturing (Andrade et al. 2002) techniques. This article starts with a brief introduction of tissue engineering (Bone tissue engineering and scaffolds) and scaffolding materials (Biomaterials used in bone tissue engineering). After a brief reviews on conventional scaffolding techniques (Conventional scaffolding techniques), a number of CAM techniques are reviewed in great detail. For each technique, the structure and mechanical integrity of fabricated scaffolds are discussed in detail. Finally, the advantaged and disadvantage of these techniques are compared (Comparison of scaffolding techniques) and summarised (Summary).

  20. Computer modeling the boron compound factor in normal brain tissue

    International Nuclear Information System (INIS)

    Gavin, P.R.; Huiskamp, R.; Wheeler, F.J.; Griebenow, M.L.

    1993-01-01

    The macroscopic distribution of borocaptate sodium (Na 2 B 12 H 11 SH or BSH) in normal tissues has been determined and can be accurately predicted from the blood concentration. The compound para-borono-phenylalanine (p-BPA) has also been studied in dogs and normal tissue distribution has been determined. The total physical dose required to reach a biological isoeffect appears to increase directly as the proportion of boron capture dose increases. This effect, together with knowledge of the macrodistribution, led to estimates of the influence of the microdistribution of the BSH compound. This paper reports a computer model that was used to predict the compound factor for BSH and p-BPA and, hence, the equivalent radiation in normal tissues. The compound factor would need to be calculated for other compounds with different distributions. This information is needed to design appropriate normal tissue tolerance studies for different organ systems and/or different boron compounds

  1. Créer de nouveaux écosystèmes durables par des méthodes bio-inspirées : le cas des toits verts extensifs en région méditerranéenne

    Directory of Open Access Journals (Sweden)

    DUTOIT, Thierry

    2016-05-01

    Full Text Available Outre l’aspect esthétique, de nombreuses études ont confirmé l’intérêt des toitures végétales dans une perspective de restauration ou de protection de la biodiversité et de l'environnement en milieu urbain. Leur mise en place exige toutefois quelques recommandations quant aux matériaux et techniques utilisés, qui doivent notamment s'inspirer des habitats naturels écologiquement proches. Les objectifs des travaux présentés ici sont d'élaborer et de tester de nouvelles techniques bio-inspirées pour la création de toits verts extensifs en climat méditerranéen sans reccours à l'irrigation permanente.

  2. 3rd International Conference on Frontiers of Intelligent Computing : Theory and Applications

    CERN Document Server

    Biswal, Bhabendra; Udgata, Siba; Mandal, JK

    2015-01-01

    Volume 1 contains 95 papers presented at FICTA 2014: Third International Conference on Frontiers in Intelligent Computing: Theory and Applications. The conference was held during 14-15, November, 2014 at Bhubaneswar, Odisha, India.  This volume contains papers mainly focused on Data Warehousing and Mining, Machine Learning, Mobile and Ubiquitous Computing, AI, E-commerce & Distributed Computing and Soft Computing, Evolutionary Computing, Bio-inspired Computing and its Applications.

  3. Experimental and computational laser tissue welding using a protein patch.

    Science.gov (United States)

    Small, W; Heredia, N J; Maitland, D J; Eder, D C; Celliers, P M; Da Silva, L B; London, R A; Matthews, D L

    1998-01-01

    An in vitro study of laser tissue welding mediated with a dye-enhanced protein patch was conducted. Fresh sections of porcine aorta were used for the experiments. Arteriotomies were treated using an indocyanine green dye-enhanced collagen patch activated by an 805-nm continuous-wave fiber-delivered diode laser. Temperature histories of the surface of the weld site were obtained using a hollow glass optical fiber-based two-color infrared thermometer. The experimental effort was complemented by simulations with the LATIS (LAser-TISsue) computer code, which uses coupled Monte Carlo, thermal transport, and mass transport models. Comparison of simulated and experimental thermal data indicated that evaporative cooling clamped the surface temperature of the weld site below 100 °C. For fluences of approximately 200 J/cm2, peak surface temperatures averaged 74°C and acute burst strengths consistently exceeded 0.14×106 dyn/cm (hoop tension). The combination of experimental and simulation results showed that the inclusion of water transport and evaporative losses in the computer code has a significant impact on the thermal distributions and hydration levels throughout the tissue volume. The solid-matrix protein patch provided a means of controllable energy delivery and yielded consistently strong welds. © 1998 Society of Photo-Optical Instrumentation Engineers.

  4. Computer aided design of architecture of degradable tissue engineering scaffolds.

    Science.gov (United States)

    Heljak, M K; Kurzydlowski, K J; Swieszkowski, W

    2017-11-01

    One important factor affecting the process of tissue regeneration is scaffold stiffness loss, which should be properly balanced with the rate of tissue regeneration. The aim of the research reported here was to develop a computer tool for designing the architecture of biodegradable scaffolds fabricated by melt-dissolution deposition systems (e.g. Fused Deposition Modeling) to provide the required scaffold stiffness at each stage of degradation/regeneration. The original idea presented in the paper is that the stiffness of a tissue engineering scaffold can be controlled during degradation by means of a proper selection of the diameter of the constituent fibers and the distances between them. This idea is based on the size-effect on degradation of aliphatic polyesters. The presented computer tool combines a genetic algorithm and a diffusion-reaction model of polymer hydrolytic degradation. In particular, we show how to design the architecture of scaffolds made of poly(DL-lactide-co-glycolide) with the required Young's modulus change during hydrolytic degradation.

  5. Comparison of Tissue Density in Hounsfield Units in Computed Tomography and Cone Beam Computed Tomography.

    Science.gov (United States)

    Varshowsaz, Masoud; Goorang, Sepideh; Ehsani, Sara; Azizi, Zeynab; Rahimian, Sepideh

    2016-03-01

    Bone quality and quantity assessment is one of the most important steps in implant treatment planning. Different methods such as computed tomography (CT) and recently suggested cone beam computed tomography (CBCT) with lower radiation dose and less time and cost are used for bone density assessment. This in vitro study aimed to compare the tissue density values in Hounsfield units (HUs) in CBCT and CT scans of different tissue phantoms with two different thicknesses, two different image acquisition settings and in three locations in the phantoms. Four different tissue phantoms namely hard tissue, soft tissue, air and water were scanned by three different CBCT and a CT system in two thicknesses (full and half) and two image acquisition settings (high and low kVp and mA). The images were analyzed at three sites (middle, periphery and intermediate) using eFilm software. The difference in density values was analyzed by ANOVA and correction coefficient test (P<0.05). There was a significant difference between density values in CBCT and CT scans in most situations, and CBCT values were not similar to CT values in any of the phantoms in different thicknesses and acquisition parameters or the three different sites. The correction coefficients confirmed the results. CBCT is not reliable for tissue density assessment. The results were not affected by changes in thickness, acquisition parameters or locations.

  6. 7th International Workshop on Natural Computing

    CERN Document Server

    Hagiya, Masami

    2015-01-01

    This book highlights recent advances in natural computing, including biology and its theory, bio-inspired computing, computational aesthetics, computational models and theories, computing with natural media, philosophy of natural computing and educational technology. It presents extended versions of the best papers selected from the symposium “7th International Workshop on Natural Computing” (IWNC7), held in Tokyo, Japan, in 2013. The target audience is not limited to researchers working in natural computing but also those active in biological engineering, fine/media art design, aesthetics and philosophy.

  7. 8th International Workshop on Natural Computing

    CERN Document Server

    Hagiya, Masami

    2016-01-01

    This book highlights recent advances in natural computing, including biology and its theory, bio-inspired computing, computational aesthetics, computational models and theories, computing with natural media, philosophy of natural computing, and educational technology. It presents extended versions of the best papers selected from the “8th International Workshop on Natural Computing” (IWNC8), a symposium held in Hiroshima, Japan, in 2014. The target audience is not limited to researchers working in natural computing but also includes those active in biological engineering, fine/media art design, aesthetics, and philosophy.

  8. Derivation of the stress-strain behavior of the constituents of bio-inspired layered TiO2/PE-nanocomposites by inverse modeling based on FE-simulations of nanoindentation test.

    Science.gov (United States)

    Lasko, G; Schäfer, I; Burghard, Z; Bill, J; Schmauder, S; Weber, U; Galler, D

    2013-03-01

    Owing to the apparent simple morphology and peculiar properties, nacre, an iridescent layer, coating of the inner part of mollusk shells, has attracted considerable attention of biologists, material scientists and engineers. The basic structural motif in nacre is the assembly of oriented plate-like aragonite crystals with a 'brick' (CaCO3 crystals) and 'mortar' (macromolecular components like proteins) organization. Many scientific researchers recognize that such structures are associated with the excellent mechanical properties of nacre and biomimetic strategies have been proposed to produce new layered nanocomposites. During the past years, increasing efforts have been devoted towards exploiting nacre's structural design principle in the synthesis of novel nanocomposites. However, the direct transfer of nacre's architecture to an artificial inorganic material has not been achieved yet. In the present contribution we report on laminated architecture, composed of the inorganic oxide (TiO2) and organic polyelectrolyte (PE) layers which fulfill this task. To get a better insight and understanding concerning the mechanical behaviour of bio-inspired layered materials consisting of oxide ceramics and organic layers, the elastic-plastic properties of titanium dioxide and organic polyelectrolyte phase are determined via FE-modelling of the nanoindentation process. With the use of inverse modeling and based on numerical models which are applied on the microscopic scale, the material properties of the constituents are derived.

  9. 6th International Conference on Computer Science and its Applications

    CERN Document Server

    Stojmenovic, Ivan; Jeong, Hwa; Yi, Gangman

    2015-01-01

    The 6th FTRA International Conference on Computer Science and its Applications (CSA-14) will be held in Guam, USA, Dec. 17 - 19, 2014. CSA-14 presents a comprehensive conference focused on the various aspects of advances in engineering systems in computer science, and applications, including ubiquitous computing, U-Health care system, Big Data, UI/UX for human-centric computing, Computing Service, Bioinformatics and Bio-Inspired Computing and will show recent advances on various aspects of computing technology, Ubiquitous Computing Services and its application.

  10. Numerical computing of elastic homogenized coefficients for periodic fibrous tissue

    Directory of Open Access Journals (Sweden)

    Roman S.

    2009-06-01

    Full Text Available The homogenization theory in linear elasticity is applied to a periodic array of cylindrical inclusions in rectangular pattern extending to infinity in the inclusions axial direction, such that the deformation of tissue along this last direction is negligible. In the plane of deformation, the homogenization scheme is based on the average strain energy whereas in the third direction it is based on the average normal stress along this direction. Namely, these average quantities have to be the same on a Repeating Unit Cell (RUC of heterogeneous and homogenized media when using a special form of boundary conditions forming by a periodic part and an affine part of displacement. It exists an infinity of RUCs generating the considered array. The computing procedure is tested with different choices of RUC to control that the results of the homogenization process are independent of the kind of RUC we employ. Then, the dependence of the homogenized coefficients on the microstructure can be studied. For instance, a special anisotropy and the role of the inclusion volume are investigated. In the second part of this work, mechanical traction tests are simulated. We consider two kinds of loading, applying a density of force or imposing a displacement. We test five samples of periodic array containing one, four, sixteen, sixty-four and one hundred of RUCs. The evolution of mean stresses, strains and energy with the numbers of inclusions is studied. Evolutions depend on the kind of loading, but not their limits, which could be predicted by simulating traction test of the homogenized medium.

  11. Interplay of multiple synaptic plasticity features in filamentary memristive devices for neuromorphic computing

    Science.gov (United States)

    La Barbera, Selina; Vincent, Adrien F.; Vuillaume, Dominique; Querlioz, Damien; Alibart, Fabien

    2016-12-01

    Bio-inspired computing represents today a major challenge at different levels ranging from material science for the design of innovative devices and circuits to computer science for the understanding of the key features required for processing of natural data. In this paper, we propose a detail analysis of resistive switching dynamics in electrochemical metallization cells for synaptic plasticity implementation. We show how filament stability associated to joule effect during switching can be used to emulate key synaptic features such as short term to long term plasticity transition and spike timing dependent plasticity. Furthermore, an interplay between these different synaptic features is demonstrated for object motion detection in a spike-based neuromorphic circuit. System level simulation presents robust learning and promising synaptic operation paving the way to complex bio-inspired computing systems composed of innovative memory devices.

  12. [Development of computer aided forming techniques in manufacturing scaffolds for bone tissue engineering].

    Science.gov (United States)

    Wei, Xuelei; Dong, Fuhui

    2011-12-01

    To review recent advance in the research and application of computer aided forming techniques for constructing bone tissue engineering scaffolds. The literature concerning computer aided forming techniques for constructing bone tissue engineering scaffolds in recent years was reviewed extensively and summarized. Several studies over last decade have focused on computer aided forming techniques for bone scaffold construction using various scaffold materials, which is based on computer aided design (CAD) and bone scaffold rapid prototyping (RP). CAD include medical CAD, STL, and reverse design. Reverse design can fully simulate normal bone tissue and could be very useful for the CAD. RP techniques include fused deposition modeling, three dimensional printing, selected laser sintering, three dimensional bioplotting, and low-temperature deposition manufacturing. These techniques provide a new way to construct bone tissue engineering scaffolds with complex internal structures. With rapid development of molding and forming techniques, computer aided forming techniques are expected to provide ideal bone tissue engineering scaffolds.

  13. NASA's Bio-Inspired Acoustic Absorber Concept

    Science.gov (United States)

    Koch, L. Danielle

    2017-01-01

    Transportation noise pollutes our worlds cities, suburbs, parks, and wilderness areas. NASAs fundamental research in aviation acoustics is helping to find innovative solutions to this multifaceted problem. NASA is learning from nature to develop the next generation of quiet aircraft.The number of road vehicles and airplanes has roughly tripled since the 1960s. Transportation noise is audible in nearly all the counties across the US. Noise can damage your hearing, raise your heart rate and blood pressure, disrupt your sleep, and make communication difficult. Noise pollution threatens wildlife when it prevents animals from hearing prey, predators, and mates. Noise regulations help drive industry to develop quieter aircraft. Noise standards for aircraft have been developed by the International Civil Aviation Organization and adopted by the US Federal Aviation Administration. The US National Park Service is working with the Federal Aviation Administration to try to balance the demand for access to the parks and wilderness areas with preservation of the natural soundscape. NASA is helping by conceptualizing quieter, more efficient aircraft of the future and performing the fundamental research to make these concepts a reality someday. Recently, NASA has developed synthetic structures that can absorb sound well over a wide frequency range, and particularly below 1000 Hz, and which mimic the acoustic performance of bundles of natural reeds. We are adapting these structures to control noise on aircraft, and spacecraft. This technology might be used in many other industrial or architectural applications where acoustic absorbers have tight constraints on weight and thickness, and may be exposed to high temperatures or liquids. Information about this technology is being made available through reports and presentations available through the NASA Technical Report Server, http:ntrs.nasa.gov. Organizations who would like to collaborate with NASA or commercialize NASAs technology are encouraged to contact the NASA Glenn Technology Transfer Office, https:technology.grc.nasa.gov. The NASA Glenn Office of Education https:www.nasa.govcentersglenneducationindex.html and the NASA Glenn Virtual Interchange for Nature-Inspired Exploration https:www.grc.nasa.govvine are also helping to make research like this accessible to the public and students of all ages.

  14. Bio-Inspired Flexible Cellular Actuating Systems

    Science.gov (United States)

    2013-11-21

    S. Hong, “Robust adaptive boundary control of a flexible marine riser with vessel dynamics,” Automatica, vol. 47, pp. 722–732, 2011. [22] D. H...conditionally accepted. [6] W. He, S. S. Ge, B. V. E. How, Y. S. Choo, and K. S. Hong, “Robust adaptive boundary control of a flexible marine riser ... flexible robotic actuators, often represented by a distributed parameter system or a partial differential equation. We establish a model-guided

  15. Bio-Inspired Micromechanical Directional Acoustic Sensor

    Science.gov (United States)

    Swan, William; Alves, Fabio; Karunasiri, Gamani

    Conventional directional sound sensors employ an array of spatially separated microphones and the direction is determined using arrival times and amplitudes. In nature, insects such as the Ormia ochracea fly can determine the direction of sound using a hearing organ much smaller than the wavelength of sound it detects. The fly's eardrums are mechanically coupled, only separated by about 1 mm, and have remarkable directional sensitivity. A micromechanical sensor based on the fly's hearing system was designed and fabricated on a silicon on insulator (SOI) substrate using MEMS technology. The sensor consists of two 1 mm2 wings connected using a bridge and to the substrate using two torsional legs. The dimensions of the sensor and material stiffness determine the frequency response of the sensor. The vibration of the wings in response to incident sound at the bending resonance was measured using a laser vibrometer and found to be about 1 μm/Pa. The electronic response of the sensor to sound was measured using integrated comb finger capacitors and found to be about 25 V/Pa. The fabricated sensors showed good directional sensitivity. In this talk, the design, fabrication and characteristics of the directional sound sensor will be described. Supported by ONR and TDSI.

  16. Bio-inspired Hybrid Carbon Nanotube Muscles

    Science.gov (United States)

    Kim, Tae Hyeob; Kwon, Cheong Hoon; Lee, Changsun; An, Jieun; Phuong, Tam Thi Thanh; Park, Sun Hwa; Lima, Márcio D.; Baughman, Ray H.; Kang, Tong Mook; Kim, Seon Jeong

    2016-05-01

    There has been continuous progress in the development for biomedical engineering systems of hybrid muscle generated by combining skeletal muscle and artificial structure. The main factor affecting the actuation performance of hybrid muscle relies on the compatibility between living cells and their muscle scaffolds during cell culture. Here, we developed a hybrid muscle powered by C2C12 skeletal muscle cells based on the functionalized multi-walled carbon nanotubes (MWCNT) sheets coated with poly(3,4-ethylenedioxythiophene) (PEDOT) to achieve biomimetic actuation. This hydrophilic hybrid muscle is physically durable in solution and responds to electric field stimulation with flexible movement. Furthermore, the biomimetic actuation when controlled by electric field stimulation results in movement similar to that of the hornworm by patterned cell culture method. The contraction and relaxation behavior of the PEDOT/MWCNT-based hybrid muscle is similar to that of the single myotube movement, but has faster relaxation kinetics because of the shape-maintenance properties of the freestanding PEDOT/MWCNT sheets in solution. Our development provides the potential possibility for substantial innovation in the next generation of cell-based biohybrid microsystems.

  17. Bio-inspired reversible underwater adhesive.

    Science.gov (United States)

    Zhao, Yanhua; Wu, Yang; Wang, Liang; Zhang, Manman; Chen, Xuan; Liu, Minjie; Fan, Jun; Liu, Junqiu; Zhou, Feng; Wang, Zuankai

    2017-12-20

    The design of smart surfaces with switchable adhesive properties in a wet environment has remained a challenge in adhesion science and materials engineering. Despite intense demands in various industrial applications and exciting progress in mimicking the remarkable wet adhesion through the delicate control of catechol chemistry, polyelectrolyte complex, and supramolecular architectures, the full recapitulation of nature's dynamic function is limited. Here, we show a facile approach to synthesize bioinspired adhesive, which entails the reversible, tunable, and fast regulation of the wet adhesion on diverse surfaces. The smart wet adhesive takes advantage of the host-guest molecular interaction and the adhesive nature of catechol chemistry, as well as the responsive polymer, allowing for screening and activation of the interfacial interaction simply by a local temperature trigger in an on-demand manner. Our work opens up an avenue for the rational design of bioinspired adhesives with performances even beyond nature.

  18. Bio-inspired organic field effect transistors

    Science.gov (United States)

    Irimia-Vladu, Mihai; Troshin, Pavel A.; Schwabegger, Günther; Bodea, Marius; Schwödiauer, Reinhard; Fergus, Jeffrey W.; Razumov, Vladimir; Bauer, Siegfried; Sariciftci, Niyazi Serdar

    2010-08-01

    Two major concerns in the world nowadays are the plastic consumption and waste. Because to the economic growth and the incessant demand of plastics in developing countries, plastics consumption is projected to increase by a factor of two to three during the actual decade1. As an intuitive example, the amount of municipal solid waste (estimated per person per year) averages ~440 kg for China, ~550 kg for the European Union and ~790 kg for the United States, with almost 50% of the waste being electronic products and plastics1,2. Green technology based on biodegradable/compostable materials is perceived as an ultimate goal for solving waste problems. Currently there are numerous efforts for producing compostable plastic materials for applications in daily life products, such as plastic bags and disposable dishware. When such low-end products are fabricated with compostable materials, electronics included in such goods should be also based on materials that are easily compostable.

  19. Bio-Inspired Polymer Membrane Surface Cleaning

    Directory of Open Access Journals (Sweden)

    Agnes Schulze

    2017-03-01

    Full Text Available To generate polyethersulfone membranes with a biocatalytically active surface, pancreatin was covalently immobilized. Pancreatin is a mixture of digestive enzymes such as protease, lipase, and amylase. The resulting membranes exhibit self-cleaning properties after “switching on” the respective enzyme by adjusting pH and temperature. Thus, the membrane surface can actively degrade a fouling layer on its surface and regain initial permeability. Fouling tests with solutions of protein, oil, and mixtures of both, were performed, and the membrane’s ability to self-clean the fouled surface was characterized. Membrane characterization was conducted by investigation of the immobilized enzyme concentration, enzyme activity, water permeation flux, fouling tests, porosimetry, X-ray photoelectron spectroscopy, and scanning electron microscopy.

  20. A bio-inspired spatial patterning circuit.

    Science.gov (United States)

    Chen, Kai-Yuan; Joe, Danial J; Shealy, James B; Land, Bruce R; Shen, Xiling

    2014-01-01

    Lateral Inhibition (LI) is a widely conserved patterning mechanism in biological systems across species. Distinct from better-known Turing patterns, LI depend on cell-cell contact rather than diffusion. We built an in silico genetic circuit model to analyze the dynamic properties of LI. The model revealed that LI amplifies differences between neighboring cells to push them into opposite states, hence forming stable 2-D patterns. Inspired by this insight, we designed and implemented an electronic circuit that recapitulates LI patterning dynamics. This biomimetic system serve as a physical model to elucidate the design principle of generating robust patterning through spatial feedback, regardless of the underlying devices being biological or electrical.

  1. Bio-inspired materials for electrochemical devices

    Science.gov (United States)

    Pawlicka, A.; Firmino, A.; Sentanin, F.; Sabadini, R. C.; Jimenez, D. E. Q.; Jayme, C. C.; Mindroiu, M.; Zgarian, R. G.; Tihan, G. T.; Rau, I.; Silva, M. M.; Nogueira, A. F.; Kanicki, J.; Kajzar, F.

    2015-10-01

    Natural macromolecules are very promising row materials to be used in modern technology including security and defense. They are abundant in nature, easy to extract and possess biocompatibility and biodegradability properties. These materials can be modified throughout chemical or physical processes, and can be doped with lithium and rare earth salts, ionic liquids, organic and inorganic acids. In this communication samples of DNA and modified DNA were doped with Prussian Blue (PB), poly(ethylene dioxythiophene) (PEDOT), europium and erbium triflate and organic dyes such as Nile Blue (NB), Disperse Red 1 (DR1) and Disperse Orange 3 (DO3). The colored or colorless membranes were characterized by electrochemical and spectroscopic measurements, and they were applied in electrochromic devices (ECDs) and dye sensitized solar cells (DSSC). ECDs change the color under applied potential, so they can modulate the intensity of transmitted light of 15 to 35%. As the electrochromic materials, WO3 or Prussian blue (PB), are usually blue colored, the color change is from transparent to blue. DNA, and the complexes: DNA-CTMA, DNA-DODA and DNAPEDOT: PSS were also investigated as either hole carrier material (HTM) or polymer electrolyte in dye-sensitized solar cells (DSSC). The DNA-based samples as HTM in small DSSCs revealed a solar energy conversion efficiency of 0.56%. Polymer electrolytes of DNA-CTMA and DNA-DODA, both with 10 wt% of LiI/I2, applied in small DSSC, exhibited the efficiencies of 0.18 and 0.66%, respectively. The obtained results show that natural macromolecules-based membranes are not only environmentally friendly but are also promising materials to be investigated for several electrochemical devices. However, to obtain better performances more research is still needed.

  2. Bio-Inspired Innovation and National Security

    Science.gov (United States)

    2010-01-01

    Doppler shift resulting from their own flight.35 They can also determine azimuth and elevation using binaural processing. Detection of wires is a...responses. The problem is that trained intelligence or military persons, psychopathic or antisocial subjects, and others can effectively beat the polygraph

  3. Una propuesta para el diagnóstico de fallos en sistemas industriales mediante el uso de estrategias bioinspiradas A proposal to fault diagnosis in industrial systems using bio-inspired strategies

    Directory of Open Access Journals (Sweden)

    Lídice Camps Echevarría

    2011-08-01

    Full Text Available In this work a study on the application of bio-inspired strategies for optimization to Fault Diagnosis in industrial systems is presented. The principal aim is to establish a basis for the development of new and viable model-based Fault Diagnosis Methods which improve some difficulties that the current methods cannot avoid. These difficulties are related mainly with fault sensitivity and robustness to external disturbances. In this study, there have been considered the Differential Evolution and the Ant Colony Optimization algorithms. This application is illustrated using simulated data of the Two tanks system benchmark. In order to analyze the advantages of these algorithms to obtain a diagnosis which needs to be sensitive to faults and robust to external disturbances, some experiments with incipient faults and noisy data have been simulated. The results indicate that the proposed approach, basically the combination of the two algorithms, characterizes a promising methodology for Fault Diagnosis.En el presente trabajo se presenta un estudio sobre la aplicación de estrategias bioinspiradas para la optimización al diagnóstico de fallos en sistemas industriales. El objetivo principal es establecer una base para el desarrollo de nuevos y viables métodos de diagnóstico de fallos basados en modelos que permitan mejorar las dificultades de los métodos actuales. Estas dificultades están relacionadas, fundamentalmente, con la sensibilidad ante la presencia de fallos y la robustez ante perturbaciones externas. En el estudio se consideraron los algoritmos Evolución Diferencial y Optimización por Colonia de Hormigas. La efectividad de la propuesta es analizada mediante experimentos con el conocido problema de prueba de los dos tanques. Los experimentos consideraron presencia de ruido en la información y fallos incipientes de manera que fuera posible analizar las ventajas de la propuesta en cuanto a diagnóstico robusto y sensible. Los resultados

  4. Improvement to the pattern of control rods of the equilibrium cycle of 18 months for the CLV using bio-inspired algorithms; Mejora del patron de barras de control del ciclo de equilibrio de 18 meses para la CLV empleando algoritmos bio-inspirados

    Energy Technology Data Exchange (ETDEWEB)

    Perusquia, R.; Ortiz, J.J.; Montes, J.L. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: rpc@nuclear.inin.mx

    2003-07-01

    Nowadays in the National Institute of Nuclear Research are carried out studies with some bio-inspired optimization techniques to improve the performance of the fuel cycles of the boiling water reactors of the Laguna Verde power plant (CLV). In the present work two bio-inspired techniques were applied with the purpose of improving the performance of a balance cycle of 18 months developed for the CLV: genetic algorithms (AG) and systems based on ants colonies (SCH). The design of the reference cycle it represents in several aspects an optimal cycle proposed starting from the experience of several operation decades with the boiling water reactors (BWR initials for Boiling Water Reactor) in the world. To try to improve their performance is beforehand a difficult challenge and it puts on test the feasibility of the optimization methods in the reloads design. The study of the bio-inspired techniques was centered exclusively on the obtaining of the control rod patterns (PBC) trying to overcome the capacity factor reached in the design of the reference cycle. It was fixed the cycle length such that the decrease of the coast down period would represent an increase of the capacity factor of the cycle; so that, it diminishes the annual cost associated with the capital cost of the plant. As consequence of the study, was found that the algorithm based on the ants colonies reaches to diminish the coast down period in five and half days respect to the original balance cycle, what represents an annual saving of $US 74,000. Since the original cycle was optimized, the above-mentioned, shows the ability of the SCH for the optimization of the cycle design. With the AG it was reach to approach to the original balance cycle with a coast down period greater in seven days estimating an annual penalization of $US 130,000. (Author)

  5. Computational model of soft tissues in the human upper airway.

    Science.gov (United States)

    Pelteret, J-P V; Reddy, B D

    2012-01-01

    This paper presents a three-dimensional finite element model of the tongue and surrounding soft tissues with potential application to the study of sleep apnoea and of linguistics and speech therapy. The anatomical data was obtained from the Visible Human Project, and the underlying histological data was also extracted and incorporated into the model. Hyperelastic constitutive models were used to describe the material behaviour, and material incompressibility was accounted for. An active Hill three-element muscle model was used to represent the muscular tissue of the tongue. The neural stimulus for each muscle group was determined through the use of a genetic algorithm-based neural control model. The fundamental behaviour of the tongue under gravitational and breathing-induced loading is investigated. It is demonstrated that, when a time-dependent loading is applied to the tongue, the neural model is able to control the position of the tongue and produce a physiologically realistic response for the genioglossus.

  6. Computer simulation of heating of biological tissue during laser radiation

    International Nuclear Information System (INIS)

    Bojanic, S.; Sreckovic, M.

    1995-01-01

    Computer model is based on an implicit finite difference scheme to solve the diffusion equation for light distribution and the bio-heat equation. A practical application of the model is to calculate the temperature distributions during thermal coagulation of prostate by radiative heating. (author)

  7. Constructing a Computer Model of the Human Eye Based on Tissue Slice Images

    OpenAIRE

    Dai, Peishan; Wang, Boliang; Bao, Chunbo; Ju, Ying

    2010-01-01

    Computer simulation of the biomechanical and biological heat transfer in ophthalmology greatly relies on having a reliable computer model of the human eye. This paper proposes a novel method on the construction of a geometric model of the human eye based on tissue slice images. Slice images were obtained from an in vitro Chinese human eye through an embryo specimen processing methods. A level set algorithm was used to extract contour points of eye tissues while a principle component analysi...

  8. Devising tissue ingrowth metrics: a contribution to the computational characterization of engineered soft tissue healing.

    Science.gov (United States)

    Alves, Antoine; Attik, Nina; Bayon, Yves; Royet, Elodie; Wirth, Carine; Bourges, Xavier; Piat, Alexis; Dolmazon, Gaëlle; Clermont, Gaëlle; Boutrand, Jean-Pierre; Grosgogeat, Brigitte; Gritsch, Kerstin

    2018-03-14

    The paradigm shift brought about by the expansion of tissue engineering and regenerative medicine away from the use of biomaterials, currently questions the value of histopathologic methods in the evaluation of biological changes. To date, the available tools of evaluation are not fully consistent and satisfactory for these advanced therapies. We have developed a new, simple and inexpensive quantitative digital approach that provides key metrics for structural and compositional characterization of the regenerated tissues. For example, metrics provide the tissue ingrowth rate (TIR) which integrates two separate indicators; the cell ingrowth rate (CIR) and the total collagen content (TCC) as featured in the equation, TIR% = CIR% + TCC%. Moreover a subset of quantitative indicators describing the directional organization of the collagen (relating structure and mechanical function of tissues), the ratio of collagen I to collagen III (remodeling quality) and the optical anisotropy property of the collagen (maturity indicator) was automatically assessed as well. Using an image analyzer, all metrics were extracted from only two serial sections stained with either Feulgen & Rossenbeck (cell specific) or Picrosirius Red F3BA (collagen specific). To validate this new procedure, three-dimensional (3D) scaffolds were intraperitoneally implanted in healthy and in diabetic rats. It was hypothesized that quantitatively, the healing tissue would be significantly delayed and of poor quality in diabetic rats in comparison to healthy rats. In addition, a chemically modified 3D scaffold was similarly implanted in a third group of healthy rats with the assumption that modulation of the ingrown tissue would be quantitatively present in comparison to the 3D scaffold-healthy group. After 21 days of implantation, both hypotheses were verified by use of this novel computerized approach. When the two methods were run in parallel, the quantitative results revealed fine details and

  9. Computer tomography for rare soft tissue tumours of the extremities

    International Nuclear Information System (INIS)

    Boettger, E.; Semerak, M.; Stoltze, D.; Rossak, K.

    1979-01-01

    Five patients with undiagnosed soft tissue masses in the extremities were examined and in two a pathological diagnosis could be made. One was an extensive, invasive fibroma (desmoid) 22 cm long which could be followed from the thigh almost into the pelvis. It was sharply demarkated form the surrounding muscles and of higher density. The second case was a 12 cm long cavernous haemangioma in the semi-membranosus muscle. This was originally hypo-dense, but showed marked increase in its density after the administration of contrast. (orig.) [de

  10. Effect of computed tomography noise and tissue heterogeneity on cerebral blood flow determination by xenon-enhanced computed tomography

    International Nuclear Information System (INIS)

    Good, W.F.; Gur, D.

    1987-01-01

    The errors associated with derivation of cerebral blood flow values by the xenon-enhanced computed tomography (CT) method have been evaluated as a function of tissue heterogeneity and CT noise. The results of this study indicate that CT noise introduces large errors in the derived flow value when data for a single, unprocessed voxel are used for this purpose. CT noise increases the derived flow values in a systematic way. Tissue heterogeneity results in a systematic error which lowers the derived flow values. Errors due to both parameters are computed for typical and extreme conditions

  11. 1st International Conference on Intelligent Computing and Communication

    CERN Document Server

    Satapathy, Suresh; Sanyal, Manas; Bhateja, Vikrant

    2017-01-01

    The book covers a wide range of topics in Computer Science and Information Technology including swarm intelligence, artificial intelligence, evolutionary algorithms, and bio-inspired algorithms. It is a collection of papers presented at the First International Conference on Intelligent Computing and Communication (ICIC2) 2016. The prime areas of the conference are Intelligent Computing, Intelligent Communication, Bio-informatics, Geo-informatics, Algorithm, Graphics and Image Processing, Graph Labeling, Web Security, Privacy and e-Commerce, Computational Geometry, Service Orient Architecture, and Data Engineering.

  12. Computational methods for describing the laser-induced mechanical response of tissue

    Energy Technology Data Exchange (ETDEWEB)

    Trucano, T.; McGlaun, J.M.; Farnsworth, A.

    1994-02-01

    Detailed computational modeling of laser surgery requires treatment of the photoablation of human tissue by high intensity pulses of laser light and the subsequent thermomechanical response of the tissue. Three distinct physical regimes must be considered to accomplish this: (1) the immediate absorption of the laser pulse by the tissue and following tissue ablation, which is dependent upon tissue light absorption characteristics; (2) the near field thermal and mechanical response of the tissue to this laser pulse, and (3) the potential far field (and longer time) mechanical response of witness tissue. Both (2) and (3) are dependent upon accurate constitutive descriptions of the tissue. We will briefly review tissue absorptivity and mechanical behavior, with an emphasis on dynamic loads characteristic of the photoablation process. In this paper our focus will center on the requirements of numerical modeling and the uncertainties of mechanical tissue behavior under photoablation. We will also discuss potential contributions that computational simulations can make in the design of surgical protocols which utilize lasers, for example, in assessing the potential for collateral mechanical damage by laser pulses.

  13. Effects of gastrointestinal tissue structure on computed dipole vectors

    Directory of Open Access Journals (Sweden)

    Pullan Andrew J

    2007-10-01

    Full Text Available Abstract Background Digestive diseases are difficult to assess without using invasive measurements. Non-invasive measurements of body surface electrical and magnetic activity resulting from underlying gastro-intestinal activity are not widely used, in large due to their difficulty in interpretation. Mathematical modelling of the underlying processes may help provide additional information. When modelling myoelectrical activity, it is common for the electrical field to be represented by equivalent dipole sources. The gastrointestinal system is comprised of alternating layers of smooth muscle (SM cells and Interstitial Cells of Cajal (ICC. In addition the small intestine has regions of high curvature as the intestine bends back upon itself. To eventually use modelling diagnostically, we must improve our understanding of the effect that intestinal structure has on dipole vector behaviour. Methods Normal intestine electrical behaviour was simulated on simple geometries using a monodomain formulation. The myoelectrical fields were then represented by their dipole vectors and an examination on the effect of structure was undertaken. The 3D intestine model was compared to a more computationally efficient 1D representation to determine the differences on the resultant dipole vectors. In addition, the conductivity values and the thickness of the different muscle layers were varied in the 3D model and the effects on the dipole vectors were investigated. Results The dipole vector orientations were largely affected by the curvature and by a transmural gradient in the electrical wavefront caused by the different properties of the SM and ICC layers. This gradient caused the dipoles to be oriented at an angle to the principal direction of electrical propagation. This angle increased when the ratio of the longitudinal and circular muscle was increased or when the the conductivity along and across the layers was increased. The 1D model was able to represent the

  14. Computational model-informed design and bioprinting of cell-patterned constructs for bone tissue engineering.

    Science.gov (United States)

    Carlier, Aurélie; Skvortsov, Gözde Akdeniz; Hafezi, Forough; Ferraris, Eleonora; Patterson, Jennifer; Koç, Bahattin; Van Oosterwyck, Hans

    2016-05-17

    Three-dimensional (3D) bioprinting is a rapidly advancing tissue engineering technology that holds great promise for the regeneration of several tissues, including bone. However, to generate a successful 3D bone tissue engineering construct, additional complexities should be taken into account such as nutrient and oxygen delivery, which is often insufficient after implantation in large bone defects. We propose that a well-designed tissue engineering construct, that is, an implant with a specific spatial pattern of cells in a matrix, will improve the healing outcome. By using a computational model of bone regeneration we show that particular cell patterns in tissue engineering constructs are able to enhance bone regeneration compared to uniform ones. We successfully bioprinted one of the most promising cell-gradient patterns by using cell-laden hydrogels with varying cell densities and observed a high cell viability for three days following the bioprinting process. In summary, we present a novel strategy for the biofabrication of bone tissue engineering constructs by designing cell-gradient patterns based on a computational model of bone regeneration, and successfully bioprinting the chosen design. This integrated approach may increase the success rate of implanted tissue engineering constructs for critical size bone defects and also can find a wider application in the biofabrication of other types of tissue engineering constructs.

  15. Characterization of breast tissue using energy-dispersive X-ray diffraction computed tomography

    International Nuclear Information System (INIS)

    Pani, S.; Cook, E.J.; Horrocks, J.A.; Jones, J.L.; Speller, R.D.

    2010-01-01

    A method for sample characterization using energy-dispersive X-ray diffraction computed tomography (EDXRDCT) is presented. The procedures for extracting diffraction patterns from the data and the corrections applied are discussed. The procedures were applied to the characterization of breast tissue samples, 6 mm in diameter. Comparison with histological sections of the samples confirmed the possibility of grouping the patterns into five families, corresponding to adipose tissue, fibrosis, poorly differentiated cancer, well differentiated cancer and benign tumour.

  16. Computational Modeling for Enhancing Soft Tissue Image Guided Surgery: An Application in Neurosurgery.

    Science.gov (United States)

    Miga, Michael I

    2016-01-01

    With the recent advances in computing, the opportunities to translate computational models to more integrated roles in patient treatment are expanding at an exciting rate. One area of considerable development has been directed towards correcting soft tissue deformation within image guided neurosurgery applications. This review captures the efforts that have been undertaken towards enhancing neuronavigation by the integration of soft tissue biomechanical models, imaging and sensing technologies, and algorithmic developments. In addition, the review speaks to the evolving role of modeling frameworks within surgery and concludes with some future directions beyond neurosurgical applications.

  17. Advances in photonic reservoir computing

    Directory of Open Access Journals (Sweden)

    Van der Sande Guy

    2017-05-01

    Full Text Available We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir’s complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  18. Advances in photonic reservoir computing

    Science.gov (United States)

    Van der Sande, Guy; Brunner, Daniel; Soriano, Miguel C.

    2017-05-01

    We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir's complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  19. Modeling an Excitable Biosynthetic Tissue with Inherent Variability for Paired Computational-Experimental Studies.

    Directory of Open Access Journals (Sweden)

    Tanmay A Gokhale

    2017-01-01

    Full Text Available To understand how excitable tissues give rise to arrhythmias, it is crucially necessary to understand the electrical dynamics of cells in the context of their environment. Multicellular monolayer cultures have proven useful for investigating arrhythmias and other conduction anomalies, and because of their relatively simple structure, these constructs lend themselves to paired computational studies that often help elucidate mechanisms of the observed behavior. However, tissue cultures of cardiomyocyte monolayers currently require the use of neonatal cells with ionic properties that change rapidly during development and have thus been poorly characterized and modeled to date. Recently, Kirkton and Bursac demonstrated the ability to create biosynthetic excitable tissues from genetically engineered and immortalized HEK293 cells with well-characterized electrical properties and the ability to propagate action potentials. In this study, we developed and validated a computational model of these excitable HEK293 cells (called "Ex293" cells using existing electrophysiological data and a genetic search algorithm. In order to reproduce not only the mean but also the variability of experimental observations, we examined what sources of variation were required in the computational model. Random cell-to-cell and inter-monolayer variation in both ionic conductances and tissue conductivity was necessary to explain the experimentally observed variability in action potential shape and macroscopic conduction, and the spatial organization of cell-to-cell conductance variation was found to not impact macroscopic behavior; the resulting model accurately reproduces both normal and drug-modified conduction behavior. The development of a computational Ex293 cell and tissue model provides a novel framework to perform paired computational-experimental studies to study normal and abnormal conduction in multidimensional excitable tissue, and the methodology of modeling

  20. Correlated responses in tissue weights measured in vivo by computer tomography in Dorset Down sheep selected for lean tissue growth

    International Nuclear Information System (INIS)

    Nsoso, S.J.; Young, M.J.; Beatson, P.R.

    2003-01-01

    The aim of this study was to estimate correlated responses in lean, fat and bone weights in vivo in Dorset Down sheep selected for lean tissue growth. Over the period 1986-1992 inclusive, the lean tissue growth line had been selected using two economic indices for an increased aggregate breeding value incorporating predicted lean and fat weights with positive and negative economic weightings, respectively. The control line was selected for no change in lean tissue growth each year. Animals were born and run on pasture all year round. X-ray computer tomography was used to estimate the weights of lean, fat and bone in vivo in the 1994-born sheep, aged 265-274 days and selected randomly into 12 rams and 12 ewes from the selected line and 10 rams and 9 ewes from the control line. The lean tissue growth line had significantly greater responses in lean weight (+0.65 + 0.10 kg) and lean percentage (+1.19 + 0.17%) and significantly lesser fat weight (-0.36 + 0.08 kg) and fat percentage (-1.88 + 0.20%) compared to the control line. There was a significant increase in bone weight (+0.27 + 0.03 kg) and bone percentage (+0.69 + 0.09%) in the lean tissue growth line compared to the control line. Responses differed significantly between sexes of the lean tissue growth line, rams having a greater response in weight of lean (+1.22 + 0.20 vs. +0.08 + 0.22 kg) and bone (+0.45 + 0.06 vs. +0.09 + 0.07 kg), and a lesser response in weight of fat (-0.03 + 0.15 vs. -0.70 + 0.16 kg) than the ewes. Selection led to significant changes in lean (increase) and fat weights (decrease), and bone weight increased. Although responses in the lean tissue growth line differed significantly between sexes, there were confounding factors due to differences in management and lack of comparison at equal stage of development. Therefore, to assess real genetic differences further studies should be conducted taking these factors into consideration

  1. Epicardial adipose tissue volume estimation by postmortem computed tomography of eviscerated hearts

    DEFF Research Database (Denmark)

    Hindsø, Louise; Jakobsen, Lykke S; Jacobsen, Christina

    2017-01-01

    Epicardial adipose tissue (EAT) may play a role in the development of coronary artery disease. The purpose of this study was to evaluate a method based on postmortem computed tomography (PMCT) for the estimation of EAT volume. We PMCT-scanned the eviscerated hearts of 144 deceased individuals, wh...

  2. Determination of electrical characteristics of body tissues for computational dosimetry studies

    International Nuclear Information System (INIS)

    Silva, Rafael Monteiro da Cruz; Domingues, Luis Adriano M.C.; Neto, Athanasio Mpalantinos; Barbosa, Carlos Ruy Nunez

    2008-01-01

    Increasing public concern about human exposure to electromagnetic fields led to the development of International Exposure Standards, which reflect the actual scientific knowledge on this subject. Existing exposure limits (reference levels), are based on maximum admissible fields or induced currents densities inside human bodies, called basic restrictions. Since those physical quantities can not be readily measured, they must be estimated using techniques of computational dosimetry. These techniques rely on accurate computational modelling of human bodies to establish the relation of external field (electric / magnetic) to induced current (internal field). Nowadays the models available for human body simulation (FEM, FDM,...) are quite accurate, specially when using geometric discretization obtained from medical imaging techniques, however the determination of tissues characteristics (permittivity and conductivity) is still an issue to be dealt with. In current studies the electrical characteristics (permittivity and conductivity) of body tissues are based on values which were obtained from measurements done on tissue simples obtained from dead bodies. However those values may not represent adequately the behaviour of living tissues. In this paper a research designed to characterize the permittivity of human body tissues is presented, consisting of measurements and simulations designed to determine, using indirect methods, the electrical behaviour of living tissues. A study of exposure assessment on a real high voltage transmission line in Brazil, using measured permittivity values combined with a finite element model of the human body is presented in the panel. (author)

  3. Measurement of facial soft tissues thickness using 3D computed tomographic images

    International Nuclear Information System (INIS)

    Jeong, Ho Gul; Kim, Kee Deog; Shin, Dong Won; Hu, Kyung Seok; Lee, Jae Bum; Park, Hyok; Park, Chang Seo; Han, Seung Ho

    2006-01-01

    To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. There were no statistically significant differences between the direct measurements and those using the 3D images(p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissue thickness more easily in forensic science and anthropology

  4. Measurement of facial soft tissues thickness using 3D computed tomographic images

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ho Gul; Kim, Kee Deog; Shin, Dong Won; Hu, Kyung Seok; Lee, Jae Bum; Park, Hyok; Park, Chang Seo [Yonsei Univ. Hospital, Seoul (Korea, Republic of); Han, Seung Ho [Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2006-03-15

    To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. There were no statistically significant differences between the direct measurements and those using the 3D images(p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissue thickness more easily in forensic science and anthropology.

  5. Unit cell-based computer-aided manufacturing system for tissue engineering

    International Nuclear Information System (INIS)

    Kang, Hyun-Wook; Park, Jeong Hun; Kang, Tae-Yun; Seol, Young-Joon; Cho, Dong-Woo

    2012-01-01

    Scaffolds play an important role in the regeneration of artificial tissues or organs. A scaffold is a porous structure with a micro-scale inner architecture in the range of several to several hundreds of micrometers. Therefore, computer-aided construction of scaffolds should provide sophisticated functionality for porous structure design and a tool path generation strategy that can achieve micro-scale architecture. In this study, a new unit cell-based computer-aided manufacturing (CAM) system was developed for the automated design and fabrication of a porous structure with micro-scale inner architecture that can be applied to composite tissue regeneration. The CAM system was developed by first defining a data structure for the computing process of a unit cell representing a single pore structure. Next, an algorithm and software were developed and applied to construct porous structures with a single or multiple pore design using solid freeform fabrication technology and a 3D tooth/spine computer-aided design model. We showed that this system is quite feasible for the design and fabrication of a scaffold for tissue engineering. (paper)

  6. Unit cell-based computer-aided manufacturing system for tissue engineering.

    Science.gov (United States)

    Kang, Hyun-Wook; Park, Jeong Hun; Kang, Tae-Yun; Seol, Young-Joon; Cho, Dong-Woo

    2012-03-01

    Scaffolds play an important role in the regeneration of artificial tissues or organs. A scaffold is a porous structure with a micro-scale inner architecture in the range of several to several hundreds of micrometers. Therefore, computer-aided construction of scaffolds should provide sophisticated functionality for porous structure design and a tool path generation strategy that can achieve micro-scale architecture. In this study, a new unit cell-based computer-aided manufacturing (CAM) system was developed for the automated design and fabrication of a porous structure with micro-scale inner architecture that can be applied to composite tissue regeneration. The CAM system was developed by first defining a data structure for the computing process of a unit cell representing a single pore structure. Next, an algorithm and software were developed and applied to construct porous structures with a single or multiple pore design using solid freeform fabrication technology and a 3D tooth/spine computer-aided design model. We showed that this system is quite feasible for the design and fabrication of a scaffold for tissue engineering.

  7. Observation of human tissue with phase-contrast x-ray computed tomography

    Science.gov (United States)

    Momose, Atsushi; Takeda, Tohoru; Itai, Yuji; Tu, Jinhong; Hirano, Keiichi

    1999-05-01

    Human tissues obtained from cancerous kidneys fixed in formalin were observed with phase-contrast X-ray computed tomography (CT) using 17.7-keV synchrotron X-rays. By measuring the distributions of the X-ray phase shift caused by samples using an X-ray interferometer, sectional images that map the distribution of the refractive index were reconstructed. Because of the high sensitivity of phase- contrast X-ray CT, a cancerous lesion was differentiated from normal tissue and a variety of other structures were revealed without the need for staining.

  8. Decomposing the Hounsfield unit: probabilistic segmentation of brain tissue in computed tomography.

    Science.gov (United States)

    Kemmling, A; Wersching, H; Berger, K; Knecht, S; Groden, C; Nölte, I

    2012-03-01

    The aim of this study was to present and evaluate a standardized technique for brain segmentation of cranial computed tomography (CT) using probabilistic partial volume tissue maps based on a database of high resolution T1 magnetic resonance images (MRI). Probabilistic tissue maps of white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF) were derived from 600 normal brain MRIs (3.0 Tesla, T1-3D-turbo-field-echo) of 2 large community-based population studies (BiDirect and SEARCH Health studies). After partial tissue segmentation (FAST 4.0), MR images were linearly registered to MNI-152 standard space (FLIRT 5.5) with non-linear refinement (FNIRT 1.0) to obtain non-binary probabilistic volume images for each tissue class which were subsequently used for CT segmentation. From 150 normal cerebral CT scans a customized reference image in standard space was constructed with iterative non-linear registration to MNI-152 space. The inverse warp of tissue-specific probability maps to CT space (MNI-152 to individual CT) was used to decompose a CT image into tissue specific components (GM, WM, CSF). Potential benefits and utility of this novel approach with regard to unsupervised quantification of CT images and possible visual enhancement are addressed. Illustrative examples of tissue segmentation in different pathological cases including perfusion CT are presented. Automated tissue segmentation of cranial CT images using highly refined tissue probability maps derived from high resolution MR images is feasible. Potential applications include automated quantification of WM in leukoaraiosis, CSF in hydrocephalic patients, GM in neurodegeneration and ischemia and perfusion maps with separate assessment of GM and WM.

  9. A systematic study of head tissue inhomogeneity and anisotropy on EEG forward problem computing

    International Nuclear Information System (INIS)

    Bashar, M.R.; Li, Y.; Wen, P.

    2010-01-01

    Full text: In this study, we propose a stochastic method to analyze the effects of inhomogeneous anisotropic tissue conductivity on electroencephalogram (EEG) in forward computation. We apply this method to an inhomogeneous and anisotropic spherical human head model. We apply stochastic finite element method based on Legendre polynomials, Karhunen-Loeve expansion and stochastic Galerkin methods. We apply Volume and Wang's constraints to restrict the anisotropic conductivities for both the white matter (WM) and the skull tissue compartments. The EEGs resulting from deterministic and stochastic FEMs are compared using statistical measurement techniques. Based on these comparisons, we find that EEGs generated by incorporating WM and skull inhomogeneous anisotropic tissue properties individually result in an average of 56.5 and 57.5% relative errors, respectively. Incorporating these tissue properties for both layers together generate 43.5% average relative error. Inhomogeneous scalp tissue causes 27% average relative error and a full inhomogeneous anisotropic model brings in an average of 45.5% relative error. The study results demonstrate that the effects of inhomogeneous anisotropic tissue conductivity are significant on EEG.

  10. A Computational Modeling Approach for Investigating Soft Tissue Balancing in Bicruciate Retaining Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Shahram Amiri

    2012-01-01

    Full Text Available Bicruciate retaining knee arthroplasty, although has shown improved functions and patient satisfaction compared to other designs of total knee replacement, remains a technically demanding option for treating severe cases of arthritic knees. One of the main challenges in bicruciate retaining arthroplasty is proper balancing of the soft tissue during the surgery. In this study biomechanics of soft tissue balancing was investigated using a validated computational model of the knee joint with high fidelity definitions of the soft tissue structures along with a Taguchi method for design of experiments. The model was used to simulate intraoperative balancing of soft tissue structures following the combinations suggested by an orthogonal array design. The results were used to quantify the corresponding effects on the laxity of the joint under anterior-posterior, internal-external, and varus-valgus loads. These effects were ranked for each ligament bundle to identify the components of laxity which were most sensitive to the corresponding surgical modifications. The resulting map of sensitivity for all the ligament bundles determined the components of laxity most suitable for examination during intraoperative balancing of the soft tissue. Ultimately, a sequence for intraoperative soft tissue balancing was suggested for a bicruciate retaining knee arthroplasty.

  11. A Computational Modeling Approach for Investigating Soft Tissue Balancing in Bicruciate Retaining Knee Arthroplasty

    Science.gov (United States)

    Amiri, Shahram; Wilson, David R.

    2012-01-01

    Bicruciate retaining knee arthroplasty, although has shown improved functions and patient satisfaction compared to other designs of total knee replacement, remains a technically demanding option for treating severe cases of arthritic knees. One of the main challenges in bicruciate retaining arthroplasty is proper balancing of the soft tissue during the surgery. In this study biomechanics of soft tissue balancing was investigated using a validated computational model of the knee joint with high fidelity definitions of the soft tissue structures along with a Taguchi method for design of experiments. The model was used to simulate intraoperative balancing of soft tissue structures following the combinations suggested by an orthogonal array design. The results were used to quantify the corresponding effects on the laxity of the joint under anterior-posterior, internal-external, and varus-valgus loads. These effects were ranked for each ligament bundle to identify the components of laxity which were most sensitive to the corresponding surgical modifications. The resulting map of sensitivity for all the ligament bundles determined the components of laxity most suitable for examination during intraoperative balancing of the soft tissue. Ultimately, a sequence for intraoperative soft tissue balancing was suggested for a bicruciate retaining knee arthroplasty. PMID:23082090

  12. Computed tomography of the soft tissues of the shoulder. Pt. 3

    International Nuclear Information System (INIS)

    Dihlmann, W.; Bandick, J.

    1988-01-01

    Computed tomography of the soft tissue of the shoulder in cases of calcifying tendinitis of the rotator cuff provides the following information: 1. Localisation of the calcium deposits within the rotator cuff. 2. Contours and density of the calcium deposits correlated with the clinical findings as described by Uhthoff et al. Ill-defined contours and non-homogeneous deposits are associated with more severe clinical features. 3. Computed tomography shows that apatite particles, which are not visible radiologically, may penetrate into the shoulder joint and produce synovitis with an effusion. This is of importance in local therapy. (orig.) [de

  13. A hybrid computational model to explore the topological characteristics of epithelial tissues.

    Science.gov (United States)

    González-Valverde, Ismael; García-Aznar, José Manuel

    2017-11-01

    Epithelial tissues show a particular topology where cells resemble a polygon-like shape, but some biological processes can alter this tissue topology. During cell proliferation, mitotic cell dilation deforms the tissue and modifies the tissue topology. Additionally, cells are reorganized in the epithelial layer and these rearrangements also alter the polygon distribution. We present here a computer-based hybrid framework focused on the simulation of epithelial layer dynamics that combines discrete and continuum numerical models. In this framework, we consider topological and mechanical aspects of the epithelial tissue. Individual cells in the tissue are simulated by an off-lattice agent-based model, which keeps the information of each cell. In addition, we model the cell-cell interaction forces and the cell cycle. Otherwise, we simulate the passive mechanical behaviour of the cell monolayer using a material that approximates the mechanical properties of the cell. This continuum approach is solved by the finite element method, which uses a dynamic mesh generated by the triangulation of cell polygons. Forces generated by cell-cell interaction in the agent-based model are also applied on the finite element mesh. Cell movement in the agent-based model is driven by the displacements obtained from the deformed finite element mesh of the continuum mechanical approach. We successfully compare the results of our simulations with some experiments about the topology of proliferating epithelial tissues in Drosophila. Our framework is able to model the emergent behaviour of the cell monolayer that is due to local cell-cell interactions, which have a direct influence on the dynamics of the epithelial tissue. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Multi-tissue computational modeling analyzes pathophysiology of type 2 diabetes in MKR mice.

    Directory of Open Access Journals (Sweden)

    Amit Kumar

    Full Text Available Computational models using metabolic reconstructions for in silico simulation of metabolic disorders such as type 2 diabetes mellitus (T2DM can provide a better understanding of disease pathophysiology and avoid high experimentation costs. There is a limited amount of computational work, using metabolic reconstructions, performed in this field for the better understanding of T2DM. In this study, a new algorithm for generating tissue-specific metabolic models is presented, along with the resulting multi-confidence level (MCL multi-tissue model. The effect of T2DM on liver, muscle, and fat in MKR mice was first studied by microarray analysis and subsequently the changes in gene expression of frank T2DM MKR mice versus healthy mice were applied to the multi-tissue model to test the effect. Using the first multi-tissue genome-scale model of all metabolic pathways in T2DM, we found out that branched-chain amino acids' degradation and fatty acids oxidation pathway is downregulated in T2DM MKR mice. Microarray data showed low expression of genes in MKR mice versus healthy mice in the degradation of branched-chain amino acids and fatty-acid oxidation pathways. In addition, the flux balance analysis using the MCL multi-tissue model showed that the degradation pathways of branched-chain amino acid and fatty acid oxidation were significantly downregulated in MKR mice versus healthy mice. Validation of the model was performed using data derived from the literature regarding T2DM. Microarray data was used in conjunction with the model to predict fluxes of various other metabolic pathways in the T2DM mouse model and alterations in a number of pathways were detected. The Type 2 Diabetes MCL multi-tissue model may explain the high level of branched-chain amino acids and free fatty acids in plasma of Type 2 Diabetic subjects from a metabolic fluxes perspective.

  15. Clinical usefulness of facial soft tissues thickness measurement using 3D computed tomographic images

    International Nuclear Information System (INIS)

    Jeong, Ho Gul; Kim, Kee Deog; Hu, Kyung Seok; Lee, Jae Bum; Park, Hyok; Han, Seung Ho; Choi, Seong Ho; Kim, Chong Kwan; Park, Chang Seo

    2006-01-01

    To evaluate clinical usefulness of facial soft tissue thickness measurement using 3D computed tomographic images. One cadaver that had sound facial soft tissues was chosen for the study. The cadaver was scanned with a Helical CT under following scanning protocols about slice thickness and table speed: 3 mm and 3 mm/sec, 5 mm and 5 mm/sec, 7 mm and 7 mm/sec. The acquired data were reconstructed 1.5, 2.5, 3.5 mm reconstruction interval respectively and the images were transferred to a personal computer. Using a program developed to measure facial soft tissue thickness in 3D image, the facial soft tissue thickness was measured. After the ten-time repeation of the measurement for ten times, repeated measure analysis of variance (ANOVA) was adopted to compare and analyze the measurements using the three scanning protocols. Comparison according to the areas was analysed by Mann-Whitney test. There were no statistically significant intraobserver differences in the measurements of the facial soft tissue thickness using the three scanning protocols (p>0.05). There were no statistically significant differences between measurements in the 3 mm slice thickness and those in the 5 mm, 7 mm slice thickness (p>0.05). There were statistical differences in the 14 of the total 30 measured points in the 5 mm slice thickness and 22 in the 7 mm slice thickness. The facial soft tissue thickness measurement using 3D images of 7 mm slice thickness is acceptable clinically, but those of 5 mm slice thickness is recommended for the more accurate measurement

  16. Computational adaptive optics for broadband interferometric tomography of tissues and cells

    Science.gov (United States)

    Adie, Steven G.; Mulligan, Jeffrey A.

    2016-03-01

    Adaptive optics (AO) can shape aberrated optical wavefronts to physically restore the constructive interference needed for high-resolution imaging. With access to the complex optical field, however, many functions of optical hardware can be achieved computationally, including focusing and the compensation of optical aberrations to restore the constructive interference required for diffraction-limited imaging performance. Holography, which employs interferometric detection of the complex optical field, was developed based on this connection between hardware and computational image formation, although this link has only recently been exploited for 3D tomographic imaging in scattering biological tissues. This talk will present the underlying imaging science behind computational image formation with optical coherence tomography (OCT) -- a beam-scanned version of broadband digital holography. Analogous to hardware AO (HAO), we demonstrate computational adaptive optics (CAO) and optimization of the computed pupil correction in 'sensorless mode' (Zernike polynomial corrections with feedback from image metrics) or with the use of 'guide-stars' in the sample. We discuss the concept of an 'isotomic volume' as the volumetric extension of the 'isoplanatic patch' introduced in astronomical AO. Recent CAO results and ongoing work is highlighted to point to the potential biomedical impact of computed broadband interferometric tomography. We also discuss the advantages and disadvantages of HAO vs. CAO for the effective shaping of optical wavefronts, and highlight opportunities for hybrid approaches that synergistically combine the unique advantages of hardware and computational methods for rapid volumetric tomography with cellular resolution.

  17. Computed tomography in soft-tissue lesions of the hand and forearm

    International Nuclear Information System (INIS)

    Schmitt, R.; Warmuth-Metz, M.; Lucas, D.; Feyerabend, T.; Schindler, G.; Lanz, U.

    1990-01-01

    Computed tomography was carried out in 32 patients with clinically equivocal soft-tissue lesions of the hand (24 times) and forearm (8 times). The CT scans were performed with the patients in standard positions; thin slices and zoom technique were used. All soft-tissue tumors were correctly diagnosed with regard to localization, size and infiltration of the surrounding tissue. The histological diagnosis was correct in tendon-sheath proliferations, deposits caused by metabolic disorders, epithelial and ganglion cysts, hemangiomas, lipomas and in one schwannoma. A malignancy was suspected and was proven to be correct in two cases. False-positive diagnoses of a malignant soft-tissue tumor were made in one case of an aggressive fibromatosis, in a rapidly progressive, ossifying myositis, and three times in the presence of postoperative scar tissue following the resection of a sarcoma. Finally, a case of proliferative myositis regarded as semimalignant was underrated by CT. The hand surgeon considered CT diagnostics to be very helpful in planning operations in an anatomically complex organ such as the hand. (orig.) [de

  18. Ovarian tissue cryopreservation by stepped vitrification and monitored by X-ray computed tomography.

    Science.gov (United States)

    Corral, Ariadna; Clavero, Macarena; Gallardo, Miguel; Balcerzyk, Marcin; Amorim, Christiani A; Parrado-Gallego, Ángel; Dolmans, Marie-Madeleine; Paulini, Fernanda; Morris, John; Risco, Ramón

    2018-04-01

    Ovarian tissue cryopreservation is, in most cases, the only fertility preservation option available for female patients soon to undergo gonadotoxic treatment. To date, cryopreservation of ovarian tissue has been carried out by both traditional slow freezing method and vitrification, but even with the best techniques, there is still a considerable loss of follicle viability. In this report, we investigated a stepped cryopreservation procedure which combines features of slow cooling and vitrification (hereafter called stepped vitrification). Bovine ovarian tissue was used as a tissue model. Stepwise increments of the Me 2 SO concentration coupled with stepwise drops-in temperature in a device specifically designed for this purpose and X-ray computed tomography were combined to investigate loading times at each step, by monitoring the attenuation of the radiation proportional to Me 2 SO permeation. Viability analysis was performed in warmed tissues by immunohistochemistry. Although further viability tests should be conducted after transplantation, preliminary results are very promising. Four protocols were explored. Two of them showed a poor permeation of the vitrification solution (P1 and P2). The other two (P3 and P4), with higher permeation, were studied in deeper detail. Out of these two protocols, P4, with a longer permeation time at -40 °C, showed the same histological integrity after warming as fresh controls. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. A computational modeling approach for the characterization of mechanical properties of 3D alginate tissue scaffolds.

    Science.gov (United States)

    Nair, K; Yan, K C; Sun, W

    2008-01-01

    Scaffold guided tissue engineering is an innovative approach wherein cells are seeded onto biocompatible and biodegradable materials to form 3-dimensional (3D) constructs that, when implanted in the body facilitate the regeneration of tissue. Tissue scaffolds act as artificial extracellular matrix providing the environment conducive for tissue growth. Characterization of scaffold properties is necessary to understand better the underlying processes involved in controlling cell behavior and formation of functional tissue. We report a computational modeling approach to characterize mechanical properties of 3D gellike biomaterial, specifically, 3D alginate scaffold encapsulated with cells. Alginate inherent nonlinearity and variations arising from minute changes in its concentration and viscosity make experimental evaluation of its mechanical properties a challenging and time consuming task. We developed an in silico model to determine the stress-strain relationship of alginate based scaffolds from experimental data. In particular, we compared the Ogden hyperelastic model to other hyperelastic material models and determined that this model was the most suitable to characterize the nonlinear behavior of alginate. We further propose a mathematical model that represents the alginate material constants in Ogden model as a function of concentrations and viscosity. This study demonstrates the model capability to predict mechanical properties of 3D alginate scaffolds.

  20. Optical imaging of oral pathological tissue using optical coherence tomography and synchrotron radiation computed microtomography

    Science.gov (United States)

    Cânjǎu, Silvana; Todea, Carmen; Sinescu, Cosmin; Negrutiu, Meda L.; Duma, Virgil; Mǎnescu, Adrian; Topalǎ, Florin I.; Podoleanu, Adrian Gh.

    2013-06-01

    The efforts aimed at early diagnosis of oral cancer should be prioritized towards developing a new screening instrument, based on optical coherence tomography (OCT), to be used directly intraorally, able to perform a fast, real time, 3D and non-invasive diagnosis of oral malignancies. The first step in this direction would be to optimize the OCT image interpretation of oral tissues. Therefore we propose plastination as a tissue preparation method that better preserves three-dimensional structure for study by new optical imaging techniques. The OCT and the synchrotron radiation computed microtomography (micro-CT) were employed for tissue sample analyze. For validating the OCT results we used the gold standard diagnostic procedure for any suspicious lesion - histopathology. This is a preliminary study of comparing features provided by OCT and Micro-CT. In the conditions of the present study, OCT proves to be a highly promising imaging modality. The use of x-ray based topographic imaging of small biological samples has been limited by the low intrinsic x-ray absorption of non-mineralized tissue and the lack of established contrast agents. Plastination can be used to enhance optical imagies of oral soft tissue samples.

  1. Optimization of scaffold design for bone tissue engineering: A computational and experimental study.

    Science.gov (United States)

    Dias, Marta R; Guedes, José M; Flanagan, Colleen L; Hollister, Scott J; Fernandes, Paulo R

    2014-04-01

    In bone tissue engineering, the scaffold has not only to allow the diffusion of cells, nutrients and oxygen but also provide adequate mechanical support. One way to ensure the scaffold has the right properties is to use computational tools to design such a scaffold coupled with additive manufacturing to build the scaffolds to the resulting optimized design specifications. In this study a topology optimization algorithm is proposed as a technique to design scaffolds that meet specific requirements for mass transport and mechanical load bearing. Several micro-structures obtained computationally are presented. Designed scaffolds were then built using selective laser sintering and the actual features of the fabricated scaffolds were measured and compared to the designed values. It was possible to obtain scaffolds with an internal geometry that reasonably matched the computational design (within 14% of porosity target, 40% for strut size and 55% for throat size in the building direction and 15% for strut size and 17% for throat size perpendicular to the building direction). These results support the use of these kind of computational algorithms to design optimized scaffolds with specific target properties and confirm the value of these techniques for bone tissue engineering. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  2. A virtual surgical training system that simulates cutting of soft tissue using a modified pre-computed elastic model.

    Science.gov (United States)

    Toe, Kyaw Kyar; Huang, Weimin; Yang, Tao; Duan, Yuping; Zhou, Jiayin; Su, Yi; Teo, Soo-Kng; Kumar, Selvaraj Senthil; Lim, Calvin Chi-Wan; Chui, Chee Kong; Chang, Stephen

    2015-08-01

    This work presents a surgical training system that incorporates cutting operation of soft tissue simulated based on a modified pre-computed linear elastic model in the Simulation Open Framework Architecture (SOFA) environment. A precomputed linear elastic model used for the simulation of soft tissue deformation involves computing the compliance matrix a priori based on the topological information of the mesh. While this process may require a few minutes to several hours, based on the number of vertices in the mesh, it needs only to be computed once and allows real-time computation of the subsequent soft tissue deformation. However, as the compliance matrix is based on the initial topology of the mesh, it does not allow any topological changes during simulation, such as cutting or tearing of the mesh. This work proposes a way to modify the pre-computed data by correcting the topological connectivity in the compliance matrix, without re-computing the compliance matrix which is computationally expensive.

  3. Computer tomographic investigation of subcutaneous adipose tissue as an indicator of body composition

    DEFF Research Database (Denmark)

    McEvoy, Fintan; Madsen, Mads T.; Nielsen, Mai B.

    2009-01-01

    Background Modern computer tomography (CT) equipment can be used to acquire whole-body data from large animals such as pigs in minutes or less. In some circumstances, computer assisted analysis of the resulting image data can identify and measure anatomical features. The thickness of subcutaneous...... adipose tissue at a specific site measured by ultrasound, is used in the pig industry to assess adiposity and inform management decisions that have an impact on reproduction, food conversion performance and sow longevity. The measurement site, called "P2", is used throughout the industry. We propose...... and expressed as a proportion of total volume (fat-index). A computer algorithm was used to determined 10,201 subcutaneous adipose thickness measurements in each pig for each scan. From these data, sites were selected where correlation with fat-index was optimal. Results Image analysis correctly identified...

  4. Response functions for computing absorbed dose to skeletal tissues from neutron irradiation

    Science.gov (United States)

    Bahadori, Amir A.; Johnson, Perry; Jokisch, Derek W.; Eckerman, Keith F.; Bolch, Wesley E.

    2011-11-01

    Spongiosa in the adult human skeleton consists of three tissues—active marrow (AM), inactive marrow (IM) and trabecularized mineral bone (TB). AM is considered to be the target tissue for assessment of both long-term leukemia risk and acute marrow toxicity following radiation exposure. The total shallow marrow (TM50), defined as all tissues lying within the first 50 µm of the bone surfaces, is considered to be the radiation target tissue of relevance for radiogenic bone cancer induction. For irradiation by sources external to the body, kerma to homogeneous spongiosa has been used as a surrogate for absorbed dose to both of these tissues, as direct dose calculations are not possible using computational phantoms with homogenized spongiosa. Recent micro-CT imaging of a 40 year old male cadaver has allowed for the accurate modeling of the fine microscopic structure of spongiosa in many regions of the adult skeleton (Hough et al 2011 Phys. Med. Biol. 56 2309-46). This microstructure, along with associated masses and tissue compositions, was used to compute specific absorbed fraction (SAF) values for protons originating in axial and appendicular bone sites (Jokisch et al 2011 Phys. Med. Biol. 56 6857-72). These proton SAFs, bone masses, tissue compositions and proton production cross sections, were subsequently used to construct neutron dose-response functions (DRFs) for both AM and TM50 targets in each bone of the reference adult male. Kerma conditions were assumed for other resultant charged particles. For comparison, AM, TM50 and spongiosa kerma coefficients were also calculated. At low incident neutron energies, AM kerma coefficients for neutrons correlate well with values of the AM DRF, while total marrow (TM) kerma coefficients correlate well with values of the TM50 DRF. At high incident neutron energies, all kerma coefficients and DRFs tend to converge as charged-particle equilibrium is established across the bone site. In the range of 10 eV to 100 Me

  5. Registration of 3D ultrasound computer tomography and MRI for evaluation of tissue correspondences

    Science.gov (United States)

    Hopp, T.; Dapp, R.; Zapf, M.; Kretzek, E.; Gemmeke, H.; Ruiter, N. V.

    2015-03-01

    3D Ultrasound Computer Tomography (USCT) is a new imaging method for breast cancer diagnosis. In the current state of development it is essential to correlate USCT with a known imaging modality like MRI to evaluate how different tissue types are depicted. Due to different imaging conditions, e.g. with the breast subject to buoyancy in USCT, a direct correlation is demanding. We present a 3D image registration method to reduce positioning differences and allow direct side-by-side comparison of USCT and MRI volumes. It is based on a two-step approach including a buoyancy simulation with a biomechanical model and free form deformations using cubic B-Splines for a surface refinement. Simulation parameters are optimized patient-specifically in a simulated annealing scheme. The method was evaluated with in-vivo datasets resulting in an average registration error below 5mm. Correlating tissue structures can thereby be located in the same or nearby slices in both modalities and three-dimensional non-linear deformations due to the buoyancy are reduced. Image fusion of MRI volumes and USCT sound speed volumes was performed for intuitive display. By applying the registration to data of our first in-vivo study with the KIT 3D USCT, we could correlate several tissue structures in MRI and USCT images and learn how connective tissue, carcinomas and breast implants observed in the MRI are depicted in the USCT imaging modes.

  6. Computational fluid dynamics modeling of momentum transport in rotating wall perfused bioreactor for cartilage tissue engineering.

    Science.gov (United States)

    Cinbiz, Mahmut N; Tığli, R Seda; Beşkardeş, Işil Gerçek; Gümüşderelioğlu, Menemşe; Colak, Uner

    2010-11-01

    In this study, computational fluid dynamics (CFD) analysis of a rotating-wall perfused-vessel (RWPV) bioreactor is performed to characterize the complex hydrodynamic environment for the simulation of cartilage development in RWPV bioreactor in the presence of tissue-engineered cartilage constructs, i.e., cell-chitosan scaffolds. Shear stress exerted on chitosan scaffolds in bioreactor was calculated for different rotational velocities in the range of 33-38 rpm. According to the calculations, the lateral and lower surfaces were exposed to 0.07926-0.11069 dyne/cm(2) and 0.05974-0.08345 dyne/cm(2), respectively, while upper surfaces of constructs were exposed to 0.09196-0.12847 dyne/cm(2). Results validate adequate hydrodynamic environment for scaffolds in RWPV bioreactor for cartilage tissue development which concludes the suitability of operational conditions of RWPV bioreactor. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Tissue

    Directory of Open Access Journals (Sweden)

    David Morrissey

    2012-01-01

    Full Text Available Purpose. In vivo gene therapy directed at tissues of mesenchymal origin could potentially augment healing. We aimed to assess the duration and magnitude of transene expression in vivo in mice and ex vivo in human tissues. Methods. Using bioluminescence imaging, plasmid and adenoviral vector-based transgene expression in murine quadriceps in vivo was examined. Temporal control was assessed using a doxycycline-inducible system. An ex vivo model was developed and optimised using murine tissue, and applied in ex vivo human tissue. Results. In vivo plasmid-based transgene expression did not silence in murine muscle, unlike in liver. Although maximum luciferase expression was higher in muscle with adenoviral delivery compared with plasmid, expression reduced over time. The inducible promoter cassette successfully regulated gene expression with maximum levels a factor of 11 greater than baseline. Expression was re-induced to a similar level on a temporal basis. Luciferase expression was readily detected ex vivo in human muscle and tendon. Conclusions. Plasmid constructs resulted in long-term in vivo gene expression in skeletal muscle, in a controllable fashion utilising an inducible promoter in combination with oral agents. Successful plasmid gene transfection in human ex vivo mesenchymal tissue was demonstrated for the first time.

  8. Measurement of breast tissue composition with dual energy cone-beam computed tomography: A postmortem study

    Energy Technology Data Exchange (ETDEWEB)

    Ding Huanjun; Ducote, Justin L.; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine, California 92697 (United States)

    2013-06-15

    Purpose: To investigate the feasibility of a three-material compositional measurement of water, lipid, and protein content of breast tissue with dual kVp cone-beam computed tomography (CT) for diagnostic purposes. Methods: Simulations were performed on a flat panel-based computed tomography system with a dual kVp technique in order to guide the selection of experimental acquisition parameters. The expected errors induced by using the proposed calibration materials were also estimated by simulation. Twenty pairs of postmortem breast samples were imaged with a flat-panel based dual kVp cone-beam CT system, followed by image-based material decomposition using calibration data obtained from a three-material phantom consisting of water, vegetable oil, and polyoxymethylene plastic. The tissue samples were then chemically decomposed into their respective water, lipid, and protein contents after imaging to allow direct comparison with data from dual energy decomposition. Results: Guided by results from simulation, the beam energies for the dual kVp cone-beam CT system were selected to be 50 and 120 kVp with the mean glandular dose divided equally between each exposure. The simulation also suggested that the use of polyoxymethylene as the calibration material for the measurement of pure protein may introduce an error of -11.0%. However, the tissue decomposition experiments, which employed a calibration phantom made out of water, oil, and polyoxymethylene, exhibited strong correlation with data from the chemical analysis. The average root-mean-square percentage error for water, lipid, and protein contents was 3.58% as compared with chemical analysis. Conclusions: The results of this study suggest that the water, lipid, and protein contents can be accurately measured using dual kVp cone-beam CT. The tissue compositional information may improve the sensitivity and specificity for breast cancer diagnosis.

  9. Computer assisted collimation gamma camera: A new approach to imaging contaminated tissues

    International Nuclear Information System (INIS)

    Quartuccio, M.; Franck, D.; Pihet, P.; Begot, S.; Jeanguillaume, C.

    2000-01-01

    Measurement systems with the capability of imaging tissues contaminated with radioactive materials would find relevant applications in medical physics research and possibly in health physics. The latter in particular depends critically on the performance achieved for sensitivity and spatial resolution. An original approach of computer assisted collimation gamma camera (French acronym CACAO) which could meet suitable characteristics has been proposed elsewhere. CACAO requires detectors with high spatial resolution. The present work was aimed at investigating the application of the CACAO principle on a laboratory testing bench using silicon detectors made of small pixels. (author)

  10. Computer assisted collimation gamma camera: A new approach to imaging contaminated tissues

    Energy Technology Data Exchange (ETDEWEB)

    Quartuccio, M.; Franck, D.; Pihet, P.; Begot, S.; Jeanguillaume, C

    2000-07-01

    Measurement systems with the capability of imaging tissues contaminated with radioactive materials would find relevant applications in medical physics research and possibly in health physics. The latter in particular depends critically on the performance achieved for sensitivity and spatial resolution. An original approach of computer assisted collimation gamma camera (French acronym CACAO) which could meet suitable characteristics has been proposed elsewhere. CACAO requires detectors with high spatial resolution. The present work was aimed at investigating the application of the CACAO principle on a laboratory testing bench using silicon detectors made of small pixels. (author)

  11. Computational adaptive optics for broadband optical interferometric tomography of biological tissue.

    Science.gov (United States)

    Adie, Steven G; Graf, Benedikt W; Ahmad, Adeel; Carney, P Scott; Boppart, Stephen A

    2012-05-08

    Aberrations in optical microscopy reduce image resolution and contrast, and can limit imaging depth when focusing into biological samples. Static correction of aberrations may be achieved through appropriate lens design, but this approach does not offer the flexibility of simultaneously correcting aberrations for all imaging depths, nor the adaptability to correct for sample-specific aberrations for high-quality tomographic optical imaging. Incorporation of adaptive optics (AO) methods have demonstrated considerable improvement in optical image contrast and resolution in noninterferometric microscopy techniques, as well as in optical coherence tomography. Here we present a method to correct aberrations in a tomogram rather than the beam of a broadband optical interferometry system. Based on Fourier optics principles, we correct aberrations of a virtual pupil using Zernike polynomials. When used in conjunction with the computed imaging method interferometric synthetic aperture microscopy, this computational AO enables object reconstruction (within the single scattering limit) with ideal focal-plane resolution at all depths. Tomographic reconstructions of tissue phantoms containing subresolution titanium-dioxide particles and of ex vivo rat lung tissue demonstrate aberration correction in datasets acquired with a highly astigmatic illumination beam. These results also demonstrate that imaging with an aberrated astigmatic beam provides the advantage of a more uniform depth-dependent signal compared to imaging with a standard gaussian beam. With further work, computational AO could enable the replacement of complicated and expensive optical hardware components with algorithms implemented on a standard desktop computer, making high-resolution 3D interferometric tomography accessible to a wider group of users and nonspecialists.

  12. Differentiation of diffuse liver disease with computer-aided tissue echo quantification

    International Nuclear Information System (INIS)

    Cha, Joo Hee; Choi, Byung Ihm; Yun, Eun Joo; Ko, Young Hwan; Song, Chi Sung; Kim, Seung Hyup; Han, Joon Koo; Kim, Tae Kyoung; Lee, Dong Hyuk; Kim, Jong Hyo

    1999-01-01

    The purpose of this study was to evaluate the efficacy of computer-aided tissue echo quantification technique in the differentiation of diffuse liver diseases. Sixty-five patients with chronic liver disease including chronic hepatitis in 21 patients, fatty liver in 11, and liver cirrhosis in 33, and 55 normal volunteers were included in this study. The sonographic images by the Sono-PACS(MARO, Seoul) was recalled and the analysis was done for the hepatic parenchymal coarseness by the program using Visual C++. Difference histogram variation (DHV), edge density (ED) and intertia of concurrence matrix (ICM) were used as the coarseness index. These three indexes were statistically significant (p<0.05) in the differentiation of these four groups. The accuracy of the differentiation between any two of four groups was 83.0%. The accuracy of the differentiation of these four groups was 70.8% at the same time. The computer-aided tissue echo quantification technique is a complementary study for the differentiation of diffuse liver disease.

  13. Optimal iodine staining of cardiac tissue for X-ray computed tomography.

    Science.gov (United States)

    Butters, Timothy D; Castro, Simon J; Lowe, Tristan; Zhang, Yanmin; Lei, Ming; Withers, Philip J; Zhang, Henggui

    2014-01-01

    X-ray computed tomography (XCT) has been shown to be an effective imaging technique for a variety of materials. Due to the relatively low differential attenuation of X-rays in biological tissue, a high density contrast agent is often required to obtain optimal contrast. The contrast agent, iodine potassium iodide ([Formula: see text]), has been used in several biological studies to augment the use of XCT scanning. Recently I2KI was used in XCT scans of animal hearts to study cardiac structure and to generate 3D anatomical computer models. However, to date there has been no thorough study into the optimal use of I2KI as a contrast agent in cardiac muscle with respect to the staining times required, which has been shown to impact significantly upon the quality of results. In this study we address this issue by systematically scanning samples at various stages of the staining process. To achieve this, mouse hearts were stained for up to 58 hours and scanned at regular intervals of 6-7 hours throughout this process. Optimal staining was found to depend upon the thickness of the tissue; a simple empirical exponential relationship was derived to allow calculation of the required staining time for cardiac samples of an arbitrary size.

  14. Automated prediction of tissue outcome after acute ischemic stroke in computed tomography perfusion images

    Science.gov (United States)

    Vos, Pieter C.; Bennink, Edwin; de Jong, Hugo; Velthuis, Birgitta K.; Viergever, Max A.; Dankbaar, Jan Willem

    2015-03-01

    Assessment of the extent of cerebral damage on admission in patients with acute ischemic stroke could play an important role in treatment decision making. Computed tomography perfusion (CTP) imaging can be used to determine the extent of damage. However, clinical application is hindered by differences among vendors and used methodology. As a result, threshold based methods and visual assessment of CTP images has not yet shown to be useful in treatment decision making and predicting clinical outcome. Preliminary results in MR studies have shown the benefit of using supervised classifiers for predicting tissue outcome, but this has not been demonstrated for CTP. We present a novel method for the automatic prediction of tissue outcome by combining multi-parametric CTP images into a tissue outcome probability map. A supervised classification scheme was developed to extract absolute and relative perfusion values from processed CTP images that are summarized by a trained classifier into a likelihood of infarction. Training was performed using follow-up CT scans of 20 acute stroke patients with complete recanalization of the vessel that was occluded on admission. Infarcted regions were annotated by expert neuroradiologists. Multiple classifiers were evaluated in a leave-one-patient-out strategy for their discriminating performance using receiver operating characteristic (ROC) statistics. Results showed that a RandomForest classifier performed optimally with an area under the ROC of 0.90 for discriminating infarct tissue. The obtained results are an improvement over existing thresholding methods and are in line with results found in literature where MR perfusion was used.

  15. Computational simulation of breast compression based on segmented breast and fibroglandular tissues on magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Tzu-Ching [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, 40402, Taiwan (China); Chen, Jeon-Hor; Nie Ke; Lin Muqing; Chang, Daniel; Nalcioglu, Orhan; Su, Min-Ying [Tu and Yuen Center for Functional Onco-Imaging and Radiological Sciences, University of California, Irvine, CA 92697 (United States); Liu Dongxu; Sun Lizhi, E-mail: shih@mail.cmu.edu.t [Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697 (United States)

    2010-07-21

    This study presents a finite element-based computational model to simulate the three-dimensional deformation of a breast and fibroglandular tissues under compression. The simulation was based on 3D MR images of the breast, and craniocaudal and mediolateral oblique compression, as used in mammography, was applied. The geometry of the whole breast and the segmented fibroglandular tissues within the breast were reconstructed using triangular meshes by using the Avizo (registered) 6.0 software package. Due to the large deformation in breast compression, a finite element model was used to simulate the nonlinear elastic tissue deformation under compression, using the MSC.Marc (registered) software package. The model was tested in four cases. The results showed a higher displacement along the compression direction compared to the other two directions. The compressed breast thickness in these four cases at a compression ratio of 60% was in the range of 5-7 cm, which is a typical range of thickness in mammography. The projection of the fibroglandular tissue mesh at a compression ratio of 60% was compared to the corresponding mammograms of two women, and they demonstrated spatially matched distributions. However, since the compression was based on magnetic resonance imaging (MRI), which has much coarser spatial resolution than the in-plane resolution of mammography, this method is unlikely to generate a synthetic mammogram close to the clinical quality. Whether this model may be used to understand the technical factors that may impact the variations in breast density needs further investigation. Since this method can be applied to simulate compression of the breast at different views and different compression levels, another possible application is to provide a tool for comparing breast images acquired using different imaging modalities--such as MRI, mammography, whole breast ultrasound and molecular imaging--that are performed using different body positions and under

  16. Multifactorial Optimization of Contrast-Enhanced Nanofocus Computed Tomography for Quantitative Analysis of Neo-Tissue Formation in Tissue Engineering Constructs.

    Directory of Open Access Journals (Sweden)

    Maarten Sonnaert

    Full Text Available To progress the fields of tissue engineering (TE and regenerative medicine, development of quantitative methods for non-invasive three dimensional characterization of engineered constructs (i.e. cells/tissue combined with scaffolds becomes essential. In this study, we have defined the most optimal staining conditions for contrast-enhanced nanofocus computed tomography for three dimensional visualization and quantitative analysis of in vitro engineered neo-tissue (i.e. extracellular matrix containing cells in perfusion bioreactor-developed Ti6Al4V constructs. A fractional factorial 'design of experiments' approach was used to elucidate the influence of the staining time and concentration of two contrast agents (Hexabrix and phosphotungstic acid and the neo-tissue volume on the image contrast and dataset quality. Additionally, the neo-tissue shrinkage that was induced by phosphotungstic acid staining was quantified to determine the operating window within which this contrast agent can be accurately applied. For Hexabrix the staining concentration was the main parameter influencing image contrast and dataset quality. Using phosphotungstic acid the staining concentration had a significant influence on the image contrast while both staining concentration and neo-tissue volume had an influence on the dataset quality. The use of high concentrations of phosphotungstic acid did however introduce significant shrinkage of the neo-tissue indicating that, despite sub-optimal image contrast, low concentrations of this staining agent should be used to enable quantitative analysis. To conclude, design of experiments allowed us to define the most optimal staining conditions for contrast-enhanced nanofocus computed tomography to be used as a routine screening tool of neo-tissue formation in Ti6Al4V constructs, transforming it into a robust three dimensional quality control methodology.

  17. All-optical reservoir computer based on saturation of absorption.

    Science.gov (United States)

    Dejonckheere, Antoine; Duport, François; Smerieri, Anteo; Fang, Li; Oudar, Jean-Louis; Haelterman, Marc; Massar, Serge

    2014-05-05

    Reservoir computing is a new bio-inspired computation paradigm. It exploits a dynamical system driven by a time-dependent input to carry out computation. For efficient information processing, only a few parameters of the reservoir needs to be tuned, which makes it a promising framework for hardware implementation. Recently, electronic, opto-electronic and all-optical experimental reservoir computers were reported. In those implementations, the nonlinear response of the reservoir is provided by active devices such as optoelectronic modulators or optical amplifiers. By contrast, we propose here the first reservoir computer based on a fully passive nonlinearity, namely the saturable absorption of a semiconductor mirror. Our experimental setup constitutes an important step towards the development of ultrafast low-consumption analog computers.

  18. Development of a computational system for management of risks in radiosterilization processes of biological tissues

    International Nuclear Information System (INIS)

    Montoya, Cynara Viterbo

    2009-01-01

    Risk management can be understood to be a systematic management which aims to identify record and control the risks of a process. Applying risk management becomes a complex activity, due to the variety of professionals involved. In order to execute risk management the following are requirements of paramount importance: the experience, discernment and judgment of a multidisciplinary team, guided by means of quality tools, so as to provide standardization in the process of investigating the cause and effects of risks and dynamism in obtaining the objective desired, i.e. the reduction and control of the risk. This work aims to develop a computational system of risk management (software) which makes it feasible to diagnose the risks of the processes of radiosterilization of biological tissues. The methodology adopted was action-research, according to which the researcher performs an active role in the establishment of the problems found, in the follow-up and in the evaluation of the actions taken owing to the problems. The scenario of this action-research was the Laboratory of Biological Tissues (LTB) in the Radiation Technology Center IPEN/CNEN-SP - Sao Paulo/Brazil. The software developed was executed in PHP and Flash/MySQL language, the server (hosting), the software is available on the Internet (www.vcrisk.com.br), which the user can access from anywhere by means of the login/access password previously sent by email to the team responsible for the tissue to be analyzed. The software presents friendly navigability whereby the user is directed step-by-step in the process of investigating the risk up to the means of reducing it. The software 'makes' the user comply with the term and present the effectiveness of the actions taken to reduce the risk. Applying this system provided the organization (LTB/CTR/IPEN) with dynamic communication, effective between the members of the multidisciplinary team: a) in decision-making; b) in lessons learned; c) in knowing the new risk

  19. Improved mathematical and computational tools for modeling photon propagation in tissue

    Science.gov (United States)

    Calabro, Katherine Weaver

    Light interacts with biological tissue through two predominant mechanisms: scattering and absorption, which are sensitive to the size and density of cellular organelles, and to biochemical composition (ex. hemoglobin), respectively. During the progression of disease, tissues undergo a predictable set of changes in cell morphology and vascularization, which directly affect their scattering and absorption properties. Hence, quantification of these optical property differences can be used to identify the physiological biomarkers of disease with interest often focused on cancer. Diffuse reflectance spectroscopy is a diagnostic tool, wherein broadband visible light is transmitted through a fiber optic probe into a turbid medium, and after propagating through the sample, a fraction of the light is collected at the surface as reflectance. The measured reflectance spectrum can be analyzed with appropriate mathematical models to extract the optical properties of the tissue, and from these, a set of physiological properties. A number of models have been developed for this purpose using a variety of approaches -- from diffusion theory, to computational simulations, and empirical observations. However, these models are generally limited to narrow ranges of tissue and probe geometries. In this thesis, reflectance models were developed for a much wider range of measurement parameters, and influences such as the scattering phase function and probe design were investigated rigorously for the first time. The results provide a comprehensive understanding of the factors that influence reflectance, with novel insights that, in some cases, challenge current assumptions in the field. An improved Monte Carlo simulation program, designed to run on a graphics processing unit (GPU), was built to simulate the data used in the development of the reflectance models. Rigorous error analysis was performed to identify how inaccuracies in modeling assumptions can be expected to affect the accuracy

  20. Computed tomography in the evaluation of soft tissue tumors. Report in 124 cases

    Energy Technology Data Exchange (ETDEWEB)

    Torricelli, P; Calo, M; Boriani, S; De Santis, G

    1986-01-01

    In order to evaluate the role of Computed Tomography (CT) in prediction of nature, staging and follow-up of soft-tessue tumors, the authors examined by CT 124 patients with soft tissue neoplasms who later underwent surgery (116 cases) or fine needle biopsy (8 cases). Comparison between CT and surgical or anatomical results showed that CT was able to correctly predict the benignancy or malignancy of the masses in 76% of cases but it was very seldom able to allow an hystological prediction. On the contrary CT was found to be a very useful tool for pre-therapeutic staging and follow-up of the tumors, because it gave many diagnostic information which influenced therapeutic choiches and strategies. 39 refs.

  1. Imaging cellular and subcellular structure of human brain tissue using micro computed tomography

    Science.gov (United States)

    Khimchenko, Anna; Bikis, Christos; Schweighauser, Gabriel; Hench, Jürgen; Joita-Pacureanu, Alexandra-Teodora; Thalmann, Peter; Deyhle, Hans; Osmani, Bekim; Chicherova, Natalia; Hieber, Simone E.; Cloetens, Peter; Müller-Gerbl, Magdalena; Schulz, Georg; Müller, Bert

    2017-09-01

    Brain tissues have been an attractive subject for investigations in neuropathology, neuroscience, and neurobiol- ogy. Nevertheless, existing imaging methodologies have intrinsic limitations in three-dimensional (3D) label-free visualisation of extended tissue samples down to (sub)cellular level. For a long time, these morphological features were visualised by electron or light microscopies. In addition to being time-consuming, microscopic investigation includes specimen fixation, embedding, sectioning, staining, and imaging with the associated artefacts. More- over, optical microscopy remains hampered by a fundamental limit in the spatial resolution that is imposed by the diffraction of visible light wavefront. In contrast, various tomography approaches do not require a complex specimen preparation and can now reach a true (sub)cellular resolution. Even laboratory-based micro computed tomography in the absorption-contrast mode of formalin-fixed paraffin-embedded (FFPE) human cerebellum yields an image contrast comparable to conventional histological sections. Data of a superior image quality was obtained by means of synchrotron radiation-based single-distance X-ray phase-contrast tomography enabling the visualisation of non-stained Purkinje cells down to the subcellular level and automated cell counting. The question arises, whether the data quality of the hard X-ray tomography can be superior to optical microscopy. Herein, we discuss the label-free investigation of the human brain ultramorphology be means of synchrotron radiation-based hard X-ray magnified phase-contrast in-line tomography at the nano-imaging beamline ID16A (ESRF, Grenoble, France). As an example, we present images of FFPE human cerebellum block. Hard X-ray tomography can provide detailed information on human tissues in health and disease with a spatial resolution below the optical limit, improving understanding of the neuro-degenerative diseases.

  2. Micro-computed tomography characterization of tissue engineering scaffolds: effects of pixel size and rotation step.

    Science.gov (United States)

    Cengiz, Ibrahim Fatih; Oliveira, Joaquim Miguel; Reis, Rui L

    2017-08-01

    Quantitative assessment of micro-structure of materials is of key importance in many fields including tissue engineering, biology, and dentistry. Micro-computed tomography (µ-CT) is an intensively used non-destructive technique. However, the acquisition parameters such as pixel size and rotation step may have significant effects on the obtained results. In this study, a set of tissue engineering scaffolds including examples of natural and synthetic polymers, and ceramics were analyzed. We comprehensively compared the quantitative results of µ-CT characterization using 15 acquisition scenarios that differ in the combination of the pixel size and rotation step. The results showed that the acquisition parameters could statistically significantly affect the quantified mean porosity, mean pore size, and mean wall thickness of the scaffolds. The effects are also practically important since the differences can be as high as 24% regarding the mean porosity in average, and 19.5 h and 166 GB regarding the characterization time and data storage per sample with a relatively small volume. This study showed in a quantitative manner the effects of such a wide range of acquisition scenarios on the final data, as well as the characterization time and data storage per sample. Herein, a clear picture of the effects of the pixel size and rotation step on the results is provided which can notably be useful to refine the practice of µ-CT characterization of scaffolds and economize the related resources.

  3. Towards personalized computational oncology: from spatial models of tumour spheroids, to organoids, to tissues.

    Science.gov (United States)

    Karolak, Aleksandra; Markov, Dmitry A; McCawley, Lisa J; Rejniak, Katarzyna A

    2018-01-01

    A main goal of mathematical and computational oncology is to develop quantitative tools to determine the most effective therapies for each individual patient. This involves predicting the right drug to be administered at the right time and at the right dose. Such an approach is known as precision medicine. Mathematical modelling can play an invaluable role in the development of such therapeutic strategies, since it allows for relatively fast, efficient and inexpensive simulations of a large number of treatment schedules in order to find the most effective. This review is a survey of mathematical models that explicitly take into account the spatial architecture of three-dimensional tumours and address tumour development, progression and response to treatments. In particular, we discuss models of epithelial acini, multicellular spheroids, normal and tumour spheroids and organoids, and multi-component tissues. Our intent is to showcase how these in silico models can be applied to patient-specific data to assess which therapeutic strategies will be the most efficient. We also present the concept of virtual clinical trials that integrate standard-of-care patient data, medical imaging, organ-on-chip experiments and computational models to determine personalized medical treatment strategies. © 2018 The Author(s).

  4. Soft computing integrating evolutionary, neural, and fuzzy systems

    CERN Document Server

    Tettamanzi, Andrea

    2001-01-01

    Soft computing encompasses various computational methodologies, which, unlike conventional algorithms, are tolerant of imprecision, uncertainty, and partial truth. Soft computing technologies offer adaptability as a characteristic feature and thus permit the tracking of a problem through a changing environment. Besides some recent developments in areas like rough sets and probabilistic networks, fuzzy logic, evolutionary algorithms, and artificial neural networks are core ingredients of soft computing, which are all bio-inspired and can easily be combined synergetically. This book presents a well-balanced integration of fuzzy logic, evolutionary computing, and neural information processing. The three constituents are introduced to the reader systematically and brought together in differentiated combinations step by step. The text was developed from courses given by the authors and offers numerous illustrations as

  5. Epicardial adipose tissue radiodensity is independently related to coronary atherosclerosis. A multidetector computed tomography study

    International Nuclear Information System (INIS)

    Pracon, R.; Kruk, M.; Kepka, C.

    2011-01-01

    Preliminary research indicates that epicardial adipose tissue (EAT) may display both anti- and proatherosclerotic properties. Because the varying radiodensities of selected human tissues assessed by multidetector computed tomography (MDCT) has been shown to reflect differences in biological characteristics, the present study investigated the hypothesis that the proatherosclerotic properties of EAT may be linked to its radiodensity. The study included 164 consecutive patients (82 females, mean age 58.8±11.1 years) with suspected coronary artery disease (CAD) undergoing MDCT coronary angiography. Coronary atherosclerosis was defined as: CAD (id est (ie), presence of at least 1 coronary stenosis ≥50%) and coronary artery calcium (CAC) determined by Agatston score. EAT radiodensity was assessed by MDCT and averaged -81.00±4.64 HU (Hounsfield unit (HU) scale). Mean CAC score was 96.0±220.0. Patients with CAD (n=36) showed higher EAT radiodensity than patients without CAD (-78.99±4.12 vs. -81.57±4.64 HU, P<0.01). In the multivariable model, only EAT radiodensity and age were independently associated with CAD (odds ratio (OR) 1.15, 95%confidence interval (CI) 1.04-1.28; OR 1.08, 95%CI 1.04-1.12; respectively). EAT radiodensity also correlated with CAC score (r=0.23, P<0.01). EAT radiodensity (P<0.001), age (P<0.001), sex (P=0.03), and past smoking (P<0.01) were independent correlates of CAC in the multivariable linear regression model. Increased EAT radiodensity is independently associated with coronary atherosclerosis, which may reflect the unfavorable, proatherosclerotic metabolic properties of more radiodense epicardial fat. (author)

  6. Three-dimensional analysis and classification of arteries in the skin and subcutaneous adipofascial tissue by computer graphics imaging.

    Science.gov (United States)

    Nakajima, H; Minabe, T; Imanishi, N

    1998-09-01

    To develop new types of surgical flaps that utilize portions of the skin and subcutaneous tissue (e.g., a thin flap or an adipofascial flap), three-dimensional investigation of the vasculature in the skin and subcutaneous tissue has been anticipated. In the present study, total-body arterial injection and three-dimensional imaging of the arteries by computer graphics were performed. The full-thickness skin and subcutaneous adipofascial tissue samples, which were obtained from fresh human cadavers injected with radio-opaque medium, were divided into three distinct layers. Angiograms of each layer were introduced into a personal computer to construct three-dimensional images. On a computer monitor, each artery was shown color-coded according to the three portions: the deep adipofascial layer, superficial adipofascial layer, and dermis. Three-dimensional computerized images of each artery in the skin and subcutaneous tissue revealed the components of each vascular plexus and permitted their classification into six types. The distribution of types in the body correlated with the tissue mobility of each area. Clinically, appreciation of the three-dimensional structure of the arteries allowed the development of several new kinds of flaps.

  7. The effect of repeated freeze-thaw cycles on human muscle tissue visualized by postmortem computed tomography (PMCT)

    NARCIS (Netherlands)

    Klop, Anthony C.; Vester, Marloes E. M.; Colman, Kerri L.; Ruijter, Jan M.; van Rijn, Rick R.; Oostra, Roelof-Jan

    2017-01-01

    The aim of this study was to determine whether effects of repetitive freeze-thaw cycles, with various thawing temperatures, on human muscle tissue can be quantified using postmortem computed tomography (PMCT) technology. An additional objective was to determine the preferred thawing temperature for

  8. Fourth International Conference on Computer Science and Its Applications (CIIA 2013)

    CERN Document Server

    Mohamed, Otmane; Bellatreche, Ladjel; Recent Advances in Robotics and Automation

    2013-01-01

        "During the last decades Computational Intelligence has emerged and showed its contributions in various broad research communities (computer science, engineering, finance, economic, decision making, etc.). This was done by proposing approaches and algorithms based either on turnkey techniques belonging to the large panoply of solutions offered by computational intelligence such as data mining, genetic algorithms, bio-inspired methods, Bayesian networks, machine learning, fuzzy logic, artificial neural networks, etc. or inspired by computational intelligence techniques to develop new ad-hoc algorithms for the problem under consideration.    This volume is a comprehensive collection of extended contributions from the 4th International Conference on Computer Science and Its Applications (CIIA’2013) organized into four main tracks: Track 1: Computational Intelligence, Track  2: Security & Network Technologies, Track  3: Information Technology and Track 4: Computer Systems and Applications. This ...

  9. Novel Approaches for Bio-inspired Mechano-Sensors

    DEFF Research Database (Denmark)

    Drimus, Alin; Bilberg, Arne

    2011-01-01

    In this paper, we present novel approaches for building tactile- array sensors for use in robotic grippers inspired from biology. We start by describing the sense of touch for humans and we continue by propos- ing dierent methods to build sensors that mimic this behaviour. For the static tactile...

  10. A survey of bio-inspired compliant legged robot designs

    International Nuclear Information System (INIS)

    Zhou Xiaodong; Bi Shusheng

    2012-01-01

    The roles of biological springs in vertebrate animals and their implementations in compliant legged robots offer significant advantages over the rigid legged ones in certain types of scenarios. A large number of robotics institutes have been attempting to work in conjunction with biologists and incorporated these principles into the design of biologically inspired robots. The motivation of this review is to investigate the most published compliant legged robots and categorize them according to the types of compliant elements adopted in their mechanical structures. Based on the typical robots investigated, the trade-off between each category is summarized. In addition, the most significant performances of these robots are compared quantitatively, and multiple available solutions for the future compliant legged robot design are suggested. Finally, the design challenges for compliant legged robots are analysed. This review will provide useful guidance for robotic designers in creating new designs by inheriting the virtues of those successful robots according to the specific tasks. (topical review)

  11. A bio-inspired hair- based acceleration sensor

    NARCIS (Netherlands)

    Droogendijk, H.

    Crickets use so-called clavate hairs to sense (gravitational) acceleration to obtain information on their orientation. Inspired by this clavate hair system, a one-axis biomimetic accelerometer has been developed and fabricated using surface micromachining and SU- 8 lithography. Measu- rements show

  12. Force generation of bio-inspired hover kinematics

    NARCIS (Netherlands)

    Vandenheede, R.B.R.; Bernal, L.P.; Morrison, C.L.; Humbert, S.

    2012-01-01

    This paper presents the results of an experimental study of the aerodynamics of an elliptical flap plate wing in pitch-plunge motion. Several wing motion kinematics are derived from the kinematics of the Agrius Convolvuli (hawk moth) in hover. The experiments are conducted at a Reynolds number of 4,

  13. Bio-Inspired Space Environment-Resistant Polymer Composite

    Data.gov (United States)

    National Aeronautics and Space Administration — Use of inorganic nanoparticles which have been recently explored for therapeutic purposes in the treatment of oxidative stress disorder, cancer and heart diseases...

  14. Investigation of a Bio-Inspired Liner Concept

    Science.gov (United States)

    Koch, L. Danielle

    2017-01-01

    Four samples of natural reeds, Phragmites australis, were tested in the NASA Langley and Glenn Normal Incidence Impedance Tubes in order to experimentally determine the acoustic absorption coefficients as a function of frequency from 400 to 3000 Hz. Six samples that mimicked the geometry of the assemblies of natural reeds were also designed and additively manufactured from ASA thermoplastic and tested. Results indicate that structures can be manufactured of synthetic materials that mimic the geometry and the low frequency acoustic absorption of natural reeds. This accomplishment demonstrates that a new class of structures can now be considered for a wide range of industrial products that need thin, lightweight, broadband acoustic absorption effective at frequencies below 1000 Hz. Aircraft engine acoustic liners and aircraft cabin acoustic liners, in particular, are two aviation applications that might benefit from further development of this concept.

  15. Bio-inspired ciliary force sensor for robotic platforms

    KAUST Repository

    Ribeiro, Pedro

    2017-01-20

    The detection of small forces is of great interest in any robotic application that involves interaction with the environment (e.g., objects manipulation, physical human-robot interaction, minimally invasive surgery), since it allows the robot to detect the contacts early on and to act accordingly. In this letter, we present a sensor design inspired by the ciliary structure frequently found in nature, consisting of an array of permanently magnetized cylinders (cilia) patterned over a giant magnetoresistance sensor (GMR). When these cylinders are deformed in shape due to applied forces, the stray magnetic field variation will change the GMR sensor resistivity, thus enabling the electrical measurement of the applied force. In this letter, we present two 3 mm × 3 mm prototypes composed of an array of five cilia with 1 mm of height and 120 and 200 μm of diameter for each prototype. A minimum force of 333 μN was measured. A simulation model for determining the magnetized cylinders average stray magnetic field is also presented.

  16. BioMAV : Bio-inspired intelligence for autonomous flight

    NARCIS (Netherlands)

    Gerke, P.K.; Langevoort, J.; Lagarde, S.; Bax, L.; Grootswagers, T.; Drenth, R.J.; Slieker, V.; Vuurpijl, L.; Haselager, P.; Sprinkhuizen-Kuyper, I.; Van Otterlo, M.; De Croon, G.C.H.E.

    2011-01-01

    This paper aims to contribute to research on biologically inspired micro air vehicles in two ways: (i) it explores a novel repertoire of behavioral modules which can be controlled through ?nite state machines (FSM) and (ii) elementary movement detectors (EMD) are combined with a center/surround edge

  17. Vorticella: A Protozoan for Bio-Inspired Engineering

    Directory of Open Access Journals (Sweden)

    Sangjin Ryu

    2016-12-01

    Full Text Available In this review, we introduce Vorticella as a model biological micromachine for microscale engineering systems. Vorticella has two motile organelles: the oral cilia of the zooid and the contractile spasmoneme in the stalk. The oral cilia beat periodically, generating a water flow that translates food particles toward the animal at speeds in the order of 0.1–1 mm/s. The ciliary flow of Vorticella has been characterized by experimental measurement and theoretical modeling, and tested for flow control and mixing in microfluidic systems. The spasmoneme contracts in a few milliseconds, coiling the stalk and moving the zooid at 15–90 mm/s. Because the spasmoneme generates tension in the order of 10–100 nN, powered by calcium ion binding, it serves as a model system for biomimetic actuators in microscale engineering systems. The spasmonemal contraction of Vorticella has been characterized by experimental measurement of its dynamics and energetics, and both live and extracted Vorticellae have been tested for moving microscale objects. We describe past work to elucidate the contraction mechanism of the spasmoneme, recognizing that past and continuing efforts will increase the possibilities of using the spasmoneme as a microscale actuator as well as leading towards bioinspired actuators mimicking the spasmoneme.

  18. Bio-inspired wooden actuators for large scale applications.

    Directory of Open Access Journals (Sweden)

    Markus Rüggeberg

    Full Text Available Implementing programmable actuation into materials and structures is a major topic in the field of smart materials. In particular the bilayer principle has been employed to develop actuators that respond to various kinds of stimuli. A multitude of small scale applications down to micrometer size have been developed, but up-scaling remains challenging due to either limitations in mechanical stiffness of the material or in the manufacturing processes. Here, we demonstrate the actuation of wooden bilayers in response to changes in relative humidity, making use of the high material stiffness and a good machinability to reach large scale actuation and application. Amplitude and response time of the actuation were measured and can be predicted and controlled by adapting the geometry and the constitution of the bilayers. Field tests in full weathering conditions revealed long-term stability of the actuation. The potential of the concept is shown by a first demonstrator. With the sensor and actuator intrinsically incorporated in the wooden bilayers, the daily change in relative humidity is exploited for an autonomous and solar powered movement of a tracker for solar modules.

  19. Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives.

    Science.gov (United States)

    Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

    2015-11-04

    Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects.

  20. Bio-inspired wooden actuators for large scale applications.

    Science.gov (United States)

    Rüggeberg, Markus; Burgert, Ingo

    2015-01-01

    Implementing programmable actuation into materials and structures is a major topic in the field of smart materials. In particular the bilayer principle has been employed to develop actuators that respond to various kinds of stimuli. A multitude of small scale applications down to micrometer size have been developed, but up-scaling remains challenging due to either limitations in mechanical stiffness of the material or in the manufacturing processes. Here, we demonstrate the actuation of wooden bilayers in response to changes in relative humidity, making use of the high material stiffness and a good machinability to reach large scale actuation and application. Amplitude and response time of the actuation were measured and can be predicted and controlled by adapting the geometry and the constitution of the bilayers. Field tests in full weathering conditions revealed long-term stability of the actuation. The potential of the concept is shown by a first demonstrator. With the sensor and actuator intrinsically incorporated in the wooden bilayers, the daily change in relative humidity is exploited for an autonomous and solar powered movement of a tracker for solar modules.

  1. Colloidal-based additive manufacturing of bio-inspired composites

    Science.gov (United States)

    Studart, Andre R.

    Composite materials in nature exhibit heterogeneous architectures that are tuned to fulfill the functional demands of the surrounding environment. Examples range from the cellulose-based organic structure of plants to highly mineralized collagen-based skeletal parts like bone and teeth. Because they are often utilized to combine opposing properties such as strength and low-density or stiffness and wear resistance, the heterogeneous architecture of natural materials can potentially address several of the technical limitations of artificial homogeneous composites. However, current man-made manufacturing technologies do not allow for the level of composition and fiber orientation control found in natural heterogeneous systems. In this talk, I will present two additive manufacturing technologies recently developed in our group to build composites with exquisite architectures only rivaled by structures made by living organisms in nature. Since the proposed techniques utilize colloidal suspensions as feedstock, understanding the physics underlying the stability, assembly and rheology of the printing inks is key to predict and control the architecture of manufactured parts. Our results will show that additive manufacturing routes offer a new exciting pathway for the fabrication of biologically-inspired composite materials with unprecedented architectures and functionalities.

  2. Bio-inspired nanostructures for implementing vertical pn-junctions

    KAUST Repository

    Saffih, Faycal

    2011-08-04

    An apparatus, system, and method having a 3D pn-junction structure are presented. One embodiment of an apparatus includes a substrate, a first doped structure, and a second doped structure. In one embodiment, the first doped structure has a first doping type. The first doped structure may be formed above the substrate and extend outwardly from an upper surface of the substrate. In one embodiment, the second doped structure has a second doping type. The second doped structure may be formed above the substrate and in contact with the first doped structure. Additionally, the second doped structure may extend outwardly from the upper surface of the substrate.

  3. Bio-inspired ciliary force sensor for robotic platforms

    KAUST Repository

    Ribeiro, Pedro; Khan, Mohammed Asadullah; Alfadhel, Ahmed; Kosel, Jü rgen; Franco, Fernando; Cardoso, Susana; Bernardino, Alexandre; Schmitz, Alexander; Santos-Victor, Jose; Jamone, Lorenzo

    2017-01-01

    The detection of small forces is of great interest in any robotic application that involves interaction with the environment (e.g., objects manipulation, physical human-robot interaction, minimally invasive surgery), since it allows the robot to detect the contacts early on and to act accordingly. In this letter, we present a sensor design inspired by the ciliary structure frequently found in nature, consisting of an array of permanently magnetized cylinders (cilia) patterned over a giant magnetoresistance sensor (GMR). When these cylinders are deformed in shape due to applied forces, the stray magnetic field variation will change the GMR sensor resistivity, thus enabling the electrical measurement of the applied force. In this letter, we present two 3 mm × 3 mm prototypes composed of an array of five cilia with 1 mm of height and 120 and 200 μm of diameter for each prototype. A minimum force of 333 μN was measured. A simulation model for determining the magnetized cylinders average stray magnetic field is also presented.

  4. Demonstrations of bio-inspired perching landing gear for UAVs

    Science.gov (United States)

    Tieu, Mindy; Michael, Duncan M.; Pflueger, Jeffery B.; Sethi, Manik S.; Shimazu, Kelli N.; Anthony, Tatiana M.; Lee, Christopher L.

    2016-04-01

    Results are presented which demonstrate the feasibility and performance of two concepts of biologically-inspired landing-gear systems that enable bird-sized, unmanned aerial vehicles (UAV's) to land, perch, and take-off from branchlike structures and/or ledges. The first concept follows the anatomy of birds that can grasp ahold of a branch and perch as tendons in their legs are tensioned. This design involves a gravity-activated, cable-driven, underactuated, graspingfoot mechanism. As the UAV lands, its weight collapses a four-bar linkage pulling a cable which curls two opposing, multi-segmented feet to grasp the landing target. Each foot is a single, compliant mechanism fabricated by simultaneouly 3D-printing a flexible thermo-plastic and a stiffer ABS plastic. The design is optimized to grasp structures over a range of shapes and sizes. Quasi-static and flight tests of this landing gear affixed to RC rotorcraft (24 cm to 550 cm in diameter) demonstrate that the aircraft can land, perch, and take-off from a tree branch, rectangular wood board, PVC pipe, metal hand rail, chair armrest, and in addition, a stone wall ledge. Stability tests show that perching is maintained under base and wind disturbances. The second design concept, inspired by roosting bats, is a two-material, 3D-printed hooking mechanism that enables the UAV to stably suspend itself from a wire or small-diameter branch. The design balances structural stiffness for support and flexibility for the perching process. A flight-test demonstrates the attaching and dis-engaging of a small, RC quadcopter from a suspended line.

  5. Bio-Inspired Distributed Decision Algorithms for Anomaly Detection

    Science.gov (United States)

    2017-03-01

    Generation Services (ETG) 3. Replay of Traffic Traces (RTT) BTG creates “ norm ” traffic background with pre-specified distribution, BTG takes in a...a cap on the IP counter to offset this artificial effect. For this reason, we also evaluated the dependence of DIAMoND performance on the IP counter... cap . 3.3.2.10 Performance Evaluation Metrics. Given the local anomaly detector is based on TCP session negotiation protocols, it is natural to

  6. Bio-inspired nanocomposite assemblies as smart skin components.

    Energy Technology Data Exchange (ETDEWEB)

    Montano, Gabriel A.; Xiao, Xiaoyin; Achyuthan, Komandoor E.; Allen, Amy; Brozik, Susan Marie; Edwards, Thayne L.; Frischknecht, Amalie Lucile; Wheeler, David Roger

    2011-09-01

    There is national interest in the development of sophisticated materials that can automatically detect and respond to chemical and biological threats without the need for human intervention. In living systems, cell membranes perform such functions on a routine basis, detecting threats, communicating with the cell, and triggering automatic responses such as the opening and closing of ion channels. The purpose of this project was to learn how to replicate simple threat detection and response functions within artificial membrane systems. The original goals toward developing 'smart skin' assemblies included: (1) synthesizing functionalized nanoparticles to produce electrochemically responsive systems within a lipid bilayer host matrices, (2) calculating the energetics of nanoparticle-lipid interactions and pore formation, and (3) determining the mechanism of insertion of nanoparticles in lipid bilayers via imaging and electrochemistry. There are a few reports of the use of programmable materials to open and close pores in rigid hosts such as mesoporous materials using either heat or light activation. However, none of these materials can regulate themselves in response to the detection of threats. The strategies we investigated in this project involve learning how to use programmable nanomaterials to automatically eliminate open channels within a lipid bilayer host when 'threats' are detected. We generated and characterized functionalized nanoparticles that can be used to create synthetic pores through the membrane and investigated methods of eliminating the pores either through electrochemistry, change in pH, etc. We also focused on characterizing the behavior of functionalized gold NPs in different lipid membranes and lipid vesicles and coupled these results to modeling efforts designed to gain an understanding of the interaction of nanoparticles within lipid assemblies.

  7. Bio-inspired smart sensors for a hexapod robot

    DEFF Research Database (Denmark)

    Bilberg, Arne

    2011-01-01

    EMICAB (Embodied Motion Intelligence for Cognitive, Autonomous Robots) is an EU founded project where a consortium of 4 Universities is working together to integrate smart body mechanics and sensors with intelligent planning and motor behavior in order to make a holistic approach to artificial...

  8. Robot fish bio-inspired fishlike underwater robots

    CERN Document Server

    Li, Zheng; Youcef-Toumi, Kamal; Alvarado, Pablo

    2015-01-01

    This book provides a comprehensive coverage on robot fish including design, modeling and optimization, control, autonomous control and applications. It gathers contributions by the leading researchers in the area. Readers will find the book very useful for designing and building robot fish, not only in theory but also in practice. Moreover, the book discusses various important issues for future research and development, including design methodology, control methodology, and autonomous control strategy. This book is intended for researchers and graduate students in the fields of robotics, ocean engineering and related areas.

  9. (YIP 10) - Bio-Inspired Interfaces for Hybrid Structures

    Science.gov (United States)

    2013-07-01

    vertebrate bones and teeth, mollusk shells and arthropod exoskeletons [1, 2]. Two interesting examples of such biological systems are gecko’s footpad...range from non-wetting painting and smart adhesives [35-41] to intricate bioinspired designs such as nano- and micro- robotics with climbing abilities...smart adhesion. Advanced Materials, 2008. 20(4): p. 711-716. 42. Wood, R.J., The first takeoff of a biologically inspired at-scale robotic insect

  10. Bio-inspired functional surfaces for advanced applications

    DEFF Research Database (Denmark)

    Malshe, Ajay; Rajurkar, Kamlakar; Samant, Anoop

    2013-01-01

    , are being evolved to a higher state of intelligent functionality. These surfaces became more efficient by using combinations of available materials, along with unique physical and chemical strategies. Noteworthy physical strategies include features such as texturing and structure, and chemical strategies...... such as sensing and actuation. These strategies collectively enable functional surfaces to deliver extraordinary adhesion, hydrophobicity, multispectral response, energy scavenging, thermal regulation, antibiofouling, and other advanced functions. Production industries have been intrigued with such biological...... surface strategies in order to learn clever surface architectures and implement those architectures to impart advanced functionalities into manufactured consumer products. This keynote paper delivers a critical review of such inspiring biological surfaces and their nonbiological product analogs, where...

  11. BioAir: Bio-Inspired Airborne Infrastructure Reconfiguration

    Science.gov (United States)

    2016-01-01

    must also minimize resource usage due to limitations on the amount of processing , memory and power onboard a node. BioAIR assumes the availability of...subsequent maintenance of tentacles, each node will take one of the following roles: “ orphan ”, “free”, “tip”, “backbone” or “extra”. The BioAIR...algorithm dictates that when a node is disconnected from the tentacle or origin it is an orphan , and as such it will change its target to the nearest

  12. Bio-inspired Iron Catalysts for Hydrocarbon Oxidations

    Energy Technology Data Exchange (ETDEWEB)

    Que, Jr., Lawrence [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-03-22

    Stereoselective oxidation of C–H and C=C bonds are catalyzed by nonheme iron enzymes. Inspired by these bioinorganic systems, our group has been exploring the use of nonheme iron complexes as catalysts for the oxidation of hydrocarbons using H2O2 as an environmentally friendly and atom-efficient oxidant in order to gain mechanistic insights into these novel transformations. In particular, we have focused on clarifying the nature of the high-valent iron oxidants likely to be involved in these transformations.

  13. Bio-inspired MOF-based Catalysts for Lignin Valorization.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Stavila, Vitalie; Ramakrishnan, Parthasarathi; Davis, Ryan Wesley

    2014-09-01

    Lignin is a potentially plentiful source of renewable organics, with %7E50Mtons/yr produced by the pulp/paper industry and 200-300 Mtons/yr projected production by a US biofuels industry. This industry must process approximately 1 billion tons of biomass to meet the US Renewable Fuel goals. However, there are currently no efficient processes for converting lignin to value-added chemicals and drop-in fuels. Lignin is therefore an opportunity for production of valuable renewable chemicals, but presents staggering technical and economic challenges due to the quantities of material involved and the strong chemical bonds comprising this polymer. Aggressive chemistries and high temperatures are required to degrade lignin without catalysts. Moreover, chemical non-uniformity among lignins leads to complex product mixtures that tend to repolymerize. Conventional petrochemical approaches (pyrolysis, catalytic cracking, gasification) are energy intensive (400-800 degC), require complicated separations, and remove valuable chemical functionality. Low-temperature (25-200 degC) alternatives are clearly desirable, but enzymes are thermally fragile and incompatible with liquid organic compounds, making them impractical for large-scale biorefining. Alternatively, homogeneous catalysts, such as recently developed vanadium complexes, must be separated from product mixtures, while many heterogenous catalysts involve costly noble metals. The objective of this project is to demonstrate proof of concept that an entirely new class of biomimetic, efficient, and industrially robust synthetic catalysts based on nanoporous Metal- Organic Frameworks (MOFs) can be developed. Although catalytic MOFs are known, catalysis of bond cleavage reactions needed for lignin degradation is completely unexplored. Thus, fundamental research is required that industry and most sponsoring agencies are currently unwilling to undertake. We introduce MOFs infiltrated with titanium and nickel species as catalysts for the C-O bond hydrogenolysis in model compounds, which mimic the b-O-4, a-O-4, and 4-O-5 linkages of natural lignin. The versatile IRMOF-74(n) series is proposed as a platform for creating efficient hydrogenolysis catalysts as it not only displays tunable pore sizes, but also has the required thermal and chemical stability. The catalytic C-O bond cleavage occurs at 10 bar hydrogen pressure and temperatures as low as 120 degC. The conversion efficiency of the aromatic ether substrates into the corresponding hydrocarbons and phenols varies as PhCH 2 CH 2 OPh > PhCH 2 OPh > PhOPh (Ph = phenyl), while the catalytic activity generally follows the following trend Ni@IRMOF-74>Ti@IRMOF-74>IRMOF-74. Conversions as high as 80%, coupled with good selectivity for hydrogenolysis vs. hydrogenation, highlight the potential of MOF-based catalysts for the selective cleavage of recalcitrant aryl-ether bonds found in lignin and other biopolymers. This project supports the DOE Integrated Biorefinery Program goals, the objective of which is to convert biomass to fuels and high-value chemicals, by addressing an important technology gap: the lack of low-temperature catalysts suitable for industrial lignin degradation. Biomass, which is %7E30 wt% lignin, constitutes a potentially major source of platform chemicals that could improve overall profitability and productivity of all energy-related products, thereby benefiting consumers and reducing national dependence on imported oil. Additionally, DoD has a strong interest in low-cost drop-in fuels (Navy Biofuel Initiative) and has signed a Memorandum of Understanding with DOE and USDA to develop a sustainable biofuels industry.

  14. Towards Bio-Inspired Chromatic Behaviours in Surveillance Robots

    Directory of Open Access Journals (Sweden)

    Sampath Kumar Karutaa Gnaniar

    2016-09-01

    Full Text Available The field of Robotics is ever growing at the same time as posing enormous challenges. Numerous works has been done in biologically inspired robotics emulating models, systems and elements of nature for the purpose of solving traditional robotics problems. Chromatic behaviours are abundant in nature across a variety of living species to achieve camouflage, signaling, and temperature regulation. The ability of these creatures to successfully blend in with their environment and communicate by changing their colour is the fundamental inspiration for our research work. In this paper, we present dwarf chameleon inspired chromatic behaviour in the context of an autonomous surveillance robot, “PACHONDHI”. In our experiments, we successfully validated the ability of the robot to autonomously change its colour in relation to the terrain that it is traversing for maximizing detectability to friendly security agents and minimizing exposure to hostile agents, as well as to communicate with fellow cooperating robots.

  15. Bio-inspired heterogeneous composites for broadband vibration mitigation.

    Science.gov (United States)

    Chen, Yanyu; Wang, Lifeng

    2015-12-08

    Structural biological materials have developed heterogeneous and hierarchical architectures that are responsible for the outstanding performance to provide protection against environmental threats including static and dynamic loading. Inspired by this observation, this research aims to develop new material and structural concepts for broadband vibration mitigation. The proposed composite materials possess a two-layered heterogeneous architecture where both layers consist of high-volume platelet-shape reinforcements and low-volume matrix, similar to the well-known "brick and mortar" microstructure of biological composites. Using finite element method, we numerically demonstrated that broadband wave attenuation zones can be achieved by tailoring the geometric features of the heterogeneous architecture. We reveal that the resulting broadband attenuation zones are gained by directly superimposing the attenuation zones in each constituent layer. This mechanism is further confirmed by the investigation into the phonon dispersion relation of each layer. Importantly, the broadband wave attenuation capability will be maintained when the mineral platelet orientation is locally manipulated, yet a contrast between the mineral platelet concentrations of the two constituent layers is essential. The findings of this work will provide new opportunities to design heterogeneous composites for broadband vibration mitigation and impact resistance under mechanically challenging environmental conditions.

  16. Zinc oxide microcapsules obtained via a bio-inspired approach

    International Nuclear Information System (INIS)

    Lipowsky, Peter; Hirscher, Michael; Hoffmann, Rudolf C; Bill, Joachim; Aldinger, Fritz

    2007-01-01

    Hollow zinc oxide microcapsules have been synthesized by a sacrificial template route involving the chemical bath deposition of nanostructured zinc oxide thin films on sulfonate-modified polystyrene microspheres and subsequent removal of the polymer core by dissolution in a solvent or by thermolysis. Scanning electron micrographs show that uniform coating of the templates is achieved when ZnO is deposited from a solution containing zinc acetate, the polymer polyvinylpyrrolidone, and a base in methanol, and that the ZnO shells remain intact after removal of the cores. A focused ion beam is used to cut slices from the spheres and demonstrate their inner morphology and hollowness. X-ray diffraction yields evidence that the shells consist of nanocrystalline ZnO with the zincite structure

  17. Bio-Inspired Nanomaterials: Protein Cage Nano-Architectures

    Science.gov (United States)

    2008-04-01

    Shevchenko, A. Weizsacker, F. (2004). Hepatitis B virus nucleocapsids (2003). Fast-response proteomics by accelerated in-gel formed by carboxy-terminally...Newman, M. & Shih, C. sin. Proteomics , 5, 2319-2321. (2005). Exposure of RNA templates and encapsidation 60. Prudova, A., Bauman, Z., Braun, A...isolated from the fungus Dactylium dendroides [I]. It is H334, Y329, G513, and T580) and water molecules. composed of three distinct domains, organized

  18. Dynamic reciprocity in bio-inspired supramolecular materials

    NARCIS (Netherlands)

    Bastings, M.M.C.

    2012-01-01

    Dynamic reciprocity, the spatio-temporal bidirectional process between evolving partners in a functional system is not only found in nature, but also applies to supramolecularly assembling architectures. In this thesis, the focus was on the understanding of nature-inspired supramolecular

  19. Bio-Optics and Bio-Inspired Optical Materials.

    Science.gov (United States)

    Tadepalli, Sirimuvva; Slocik, Joseph M; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

    2017-10-25

    Through the use of the limited materials palette, optimally designed micro- and nanostructures, and tightly regulated processes, nature demonstrates exquisite control of light-matter interactions at various length scales. In fact, control of light-matter interactions is an important element in the evolutionary arms race and has led to highly engineered optical materials and systems. In this review, we present a detailed summary of various optical effects found in nature with a particular emphasis on the materials and optical design aspects responsible for their optical functionality. Using several representative examples, we discuss various optical phenomena, including absorption and transparency, diffraction, interference, reflection and antireflection, scattering, light harvesting, wave guiding and lensing, camouflage, and bioluminescence, that are responsible for the unique optical properties of materials and structures found in nature and biology. Great strides in understanding the design principles adapted by nature have led to a tremendous progress in realizing biomimetic and bioinspired optical materials and photonic devices. We discuss the various micro- and nanofabrication techniques that have been employed for realizing advanced biomimetic optical structures.

  20. Adaptive bio-inspired navigation for planetary exploration, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Exploration of planetary environments with current robotic technologies relies on human control and power-hungry active sensors to perform even the most elementary...

  1. Bio-inspired method to obtain multifunctional dynamic nanocomposites

    Science.gov (United States)

    Kushner, Aaron M.; Guan, Zhibin; Williams, Gregory; Chen, Yulin

    2018-04-10

    A method for a polymeric or nanocomposite material. The method includes assembling a multiphase hard-soft structure, where the structure includes a hard micro- or nano-phase, and a soft micro- or nano-phase that includes a polymeric scaffold. In the method, the polymeric scaffold includes dynamically interacting motifs and has a glass transition temperature (T.sub.g) lower than the intended operating temperature of the material.

  2. Bio-inspired nanostructures for implementing vertical pn-junctions

    KAUST Repository

    Saffih, Faycal

    2011-01-01

    An apparatus, system, and method having a 3D pn-junction structure are presented. One embodiment of an apparatus includes a substrate, a first doped structure, and a second doped structure. In one embodiment, the first doped structure has a first doping type. The first doped structure may be formed above the substrate and extend outwardly from an upper surface of the substrate. In one embodiment, the second doped structure has a second doping type. The second doped structure may be formed above the substrate and in contact with the first doped structure. Additionally, the second doped structure may extend outwardly from the upper surface of the substrate.

  3. Bio-Inspired Extreme Wetting Surfaces for Biomedical Applications

    Science.gov (United States)

    Shin, Sera; Seo, Jungmok; Han, Heetak; Kang, Subin; Kim, Hyunchul; Lee, Taeyoon

    2016-01-01

    Biological creatures with unique surface wettability have long served as a source of inspiration for scientists and engineers. More specifically, materials exhibiting extreme wetting properties, such as superhydrophilic and superhydrophobic surfaces, have attracted considerable attention because of their potential use in various applications, such as self-cleaning fabrics, anti-fog windows, anti-corrosive coatings, drag-reduction systems, and efficient water transportation. In particular, the engineering of surface wettability by manipulating chemical properties and structure opens emerging biomedical applications ranging from high-throughput cell culture platforms to biomedical devices. This review describes design and fabrication methods for artificial extreme wetting surfaces. Next, we introduce some of the newer and emerging biomedical applications using extreme wetting surfaces. Current challenges and future prospects of the surfaces for potential biomedical applications are also addressed. PMID:28787916

  4. Natural fibres actuators for smart bio-inspired hygromorph biocomposites

    Science.gov (United States)

    Le Duigou, Antoine; Requile, Samuel; Beaugrand, Johnny; Scarpa, Fabrizio; Castro, Mickael

    2017-12-01

    Hygromorph biocomposite (HBC) actuators make use of the transport properties of plant fibres to generate an out-of-plane displacement when a moisture gradient is present. HBC actuators possess a design based on the bilayer configuration of natural hygromorph actuators (like pine cone, wheat awn, Selaginella lepidophyll). In this work we present a series of design guidelines for HBCs with improved performance, low environmental footprints and high durability in severe environments. We develop a theoretical actuating response (curvature) formulation of maleic anhydride polypropylene (MAPP)/plant fibres based on bimetallic actuators theory. The actuation response is evaluated as a function of the fibre type (flax, jute, kenaf and coir). We demonstrate that the actuation is directly related to the fibre microstructure and its biochemical composition. The jute and flax fibres appear to be the best candidates for use in HBCs. Flax/MAPP and jute/MAPP HBCs exhibit similar actuating behaviours during the sorption phase (amplitude and speed), but different desorption characteristics due to the combined effect of the lumen size, fibre division and biochemical composition on the desorption mechanism. During hygromechanical fatigue tests the jute/MAPP HBCs exhibit a drastic improvement in durability compared to their flax counterparts. We also provide a demonstration on how HBCs can be used to trigger deployment of more complex structures based on Origami and Kirigami designs.

  5. Optimization Of Bio-inspired Hair Sensor Arrays

    NARCIS (Netherlands)

    Jaganatharaja, R.K.; Bruinink, C.M.; Izadi, N.; Lammerink, Theodorus S.J.; Wiegerink, Remco J.; Casas, J.; Krijnen, Gijsbertus J.M.

    2008-01-01

    Crickets use a pair of hairy appendages on their abdomen called cerci, each of which contains numerous mechano-receptive filiform hairs. These sensitive hairs can respond even to the slightest air movements, down to 0.03 mm/s, generated by the approaching predators and initiating an escape mechanism

  6. Mechanical Behavior of Bio-inspired Model Suture Joints

    Science.gov (United States)

    Li, Yaning; Lin, Erica; Ortiz, Christine; Boyce, Mary

    2012-02-01

    Suture joints of varying degrees of geometric complexity are prevalent throughout nature as a means of joining structural elements while providing locally tailored mechanical performance. Here, micromechanical models of general trapezoidal waveforms of varying hierarchy are formulated to reveal the role of geometric complexity in governing stiffness, strength, toughness and corresponding deformation and failure mechanisms. Physical constructs of model composite suture systems are fabricated via multi-material 3D printing (Object Connex500). Tensile tests are conducted on samples covering a range in geometry, thus providing quantitative measures of stiffness, strength, and failure. The experiments include direct visualization of the deformation and failure mechanisms and their progression, as well as their dependence on suture geometry, showing the interplay between shear and tension/compression of the interfacial layers and tension of the skeletal teeth and the transition in failure modes with geometry. The results provide quantitative guidelines for the design and tailoring of suture geometry to achieve the desired mechanical properties and also facilitate understanding of suture growth and fusion, and evolutionary phenotype.

  7. Mussel-inspired tough hydrogels with self-repairing and tissue adhesion

    Science.gov (United States)

    Gao, Zijian; Duan, Lijie; Yang, Yongqi; Hu, Wei; Gao, Guanghui

    2018-01-01

    The mussel-inspired polymeric hydrogels have been attractively explored owing to their self-repairing or adhesive property when the catechol groups of dopamine could chelate metal ions. However, it was a challenge for self-repairing hydrogels owning high mechanical properties. Herein, a synergistic strategy was proposed by combining catechol-Fe3+ complexes and hydrophobic association. The resulting hydrogels exhibited seamless self-repairing behavior, tissue adhesion and high mechanical property. Moreover, the pH-dependent stoichiometry of catechol-Fe3+ and temperature-sensitive hydrophobic association endue hydrogels with pH/thermo responsive characteristics. Subsequently, the self-repairing rate and mechanical property of hydrogels were investigated at different pH and temperature. This bio-inspired strategy would build an avenue for designing and constructing a new generation of self-repairing, tissue-adhesive and tough hydrogel.

  8. Safety of intravenous tissue plasminogen activator administration with computed tomography evidence of prior infarction.

    Science.gov (United States)

    Lyerly, Michael J; Houston, J Thomas; Boehme, Amelia K; Albright, Karen C; Bavarsad Shahripour, Reza; Palazzo, Paola; Alvi, Muhammed; Rawal, Pawan V; Kapoor, Niren; Sisson, April; Alexandrov, Anne W; Alexandrov, Andrei V

    2014-07-01

    Prior stroke within 3 months excludes patients from thrombolysis; however, patients may have computed tomography (CT) evidence of prior infarct, often of unknown time of origin. We aimed to determine if the presence of a previous infarct on pretreatment CT is a predictor of hemorrhagic complications and functional outcomes after the administration of intravenous (IV) tissue plasminogen activator (tPA). We retrospectively analyzed consecutive patients treated with IV tPA at our institution from 2009-2011. Pretreatment CTs were reviewed for evidence of any prior infarct. Further review determined if any hemorrhagic transformation (HT) or symptomatic intracerebral hemorrhage (sICH) were present on repeat CT or magnetic resonance imaging. Outcomes included sICH, any HT, poor functional outcome (modified Rankin Scale score of 4-6), and discharge disposition. Of 212 IV tPA-treated patients, 84 (40%) had evidence of prior infarct on pretreatment CT. Patients with prior infarcts on CT were older (median age, 72 versus 65 years; P=.001) and had higher pretreatment National Institutes of Health Stroke Scale scores (median, 10 versus 7; P=.023). Patients with prior infarcts on CT did not experience more sICH (4% versus 2%; P=.221) or any HT (18% versus 14%; P=.471). These patients did have a higher frequency of poor functional outcome at discharge (82% versus 50%; P<.001) and were less often discharged to home or inpatient rehabilitation center (61% versus 73%; P=.065). Visualization of prior infarcts on pretreatment CT did not predict an increased risk of sICH in our study and should not be viewed as a reason to withhold systemic tPA treatment after clinically evident strokes within 3 months were excluded. Published by Elsevier Inc.

  9. Advanced computer-aided design for bone tissue-engineering scaffolds.

    Science.gov (United States)

    Ramin, E; Harris, R A

    2009-04-01

    The design of scaffolds with an intricate and controlled internal structure represents a challenge for tissue engineering. Several scaffold-manufacturing techniques allow the creation of complex architectures but with little or no control over the main features of the channel network such as the size, shape, and interconnectivity of each individual channel, resulting in intricate but random structures. The combined use of computer-aided design (CAD) systems and layer-manufacturing techniques allows a high degree of control over these parameters with few limitations in terms of achievable complexity. However, the design of complex and intricate networks of channels required in CAD is extremely time-consuming since manually modelling hundreds of different geometrical elements, all with different parameters, may require several days to design individual scaffold structures. An automated design methodology is proposed by this research to overcome these limitations. This approach involves the investigation of novel software algorithms, which are able to interact with a conventional CAD program and permit the automated design of several geometrical elements, each with a different size and shape. In this work, the variability of the parameters required to define each geometry has been set as random, but any other distribution could have been adopted. This methodology has been used to design five cubic scaffolds with interconnected pore channels that range from 200 to 800 microm in diameter, each with an increased complexity of the internal geometrical arrangement. A clinical case study, consisting of an integration of one of these geometries with a craniofacial implant, is then presented.

  10. Determination of tissue equivalent materials of a physical 8-year-old phantom for use in computed tomography

    International Nuclear Information System (INIS)

    Akhlaghi, Parisa; Miri Hakimabad, Hashem; Rafat Motavalli, Laleh

    2015-01-01

    This paper reports on the methodology applied to select suitable tissue equivalent materials of an 8-year phantom for use in computed tomography (CT) examinations. To find the appropriate tissue substitutes, first physical properties (physical density, electronic density, effective atomic number, mass attenuation coefficient and CT number) of different materials were studied. Results showed that, the physical properties of water and polyurethane (as soft tissue), B-100 and polyvinyl chloride (PVC) (as bone) and polyurethane foam (as lung) agree more with those of original tissues. Then in the next step, the absorbed doses in the location of 25 thermoluminescent dosimeters (TLDs) as well as dose distribution in one slice of phantom were calculated for original and these proposed materials by Monte Carlo simulation at different tube voltages. The comparisons suggested that at tube voltages of 80 and 100 kVp using B-100 as bone, water as soft tissue and polyurethane foam as lung is suitable for dosimetric study in pediatric CT examinations. In addition, it was concluded that by considering just the mass attenuation coefficient of different materials, the appropriate tissue equivalent substitutes in each desired X-ray energy range could be found. - Highlights: • A methodology to select tissue equivalent materials for use in CT was proposed. • Physical properties of different materials were studied. • TLDs dose and dose distribution were calculated for original and proposed materials. • B-100 as bone, and water as soft tissue are best substitute materials at 80 kVp. • Mass attenuation coefficient is determinant for selecting best tissue substitutes

  11. Accuracy and reliability of facial soft tissue depth measurements using cone beam computer tomography

    NARCIS (Netherlands)

    Fourie, Zacharias; Damstra, Janalt; Gerrits, Pieter; Ren, Yijin

    2010-01-01

    It is important to have accurate and reliable measurements of soft tissue thickness for specific landmarks of the face and scalp when producing a facial reconstruction. In the past several methods have been created to measure facial soft tissue thickness (FSTT) in cadavers and in the living. The

  12. ORION: a computer code for evaluating environmental concentrations and dose equivalent to human organs or tissue from airborne radionuclides

    International Nuclear Information System (INIS)

    Shinohara, K.; Nomura, T.; Iwai, M.

    1983-05-01

    The computer code ORION has been developed to evaluate the environmental concentrations and the dose equivalent to human organs or tissue from air-borne radionuclides released from multiple nuclear installations. The modified Gaussian plume model is applied to calculate the dispersion of the radionuclide. Gravitational settling, dry deposition, precipitation scavenging and radioactive decay are considered to be the causes of depletion and deposition on the ground or on vegetation. ORION is written in the FORTRAN IV language and can be run on IBM 360, 370, 303X, 43XX and FACOM M-series computers. 8 references, 6 tables

  13. Computed tomography of the soft tissues of the shoulder. Pt. 3. Calcifying tendinitis of the rotator cuff

    Energy Technology Data Exchange (ETDEWEB)

    Dihlmann, W.; Bandick, J.

    1988-01-01

    Computed tomography of the soft tissue of the shoulder in cases of calcifying tendinitis of the rotator cuff provides the following information: 1. Localisation of the calcium deposits within the rotator cuff. 2. Contours and density of the calcium deposits correlated with the clinical findings as described by Uhthoff et al. Ill-defined contours and non-homogeneous deposits are associated with more severe clinical features. 3. Computed tomography shows that apatite particles, which are not visible radiologically, may penetrate into the shoulder joint and produce synovitis with an effusion. This is of importance in local therapy.

  14. Three-dimensional multislice spiral computed tomographic angiography: a potentially useful tool for safer free tissue transfer to complicated regions

    DEFF Research Database (Denmark)

    Demirtas, Yener; Cifci, Mehmet; Kelahmetoglu, Osman

    2009-01-01

    Three-dimensional multislice spiral computed tomographic angiography (3D-MSCTA) is a minimally invasive method of vascular mapping. The aim of this study was to evaluate the clinical usefulness of this imaging technique in delineating the recipient vessels for safer free tissue transfer to compli......Three-dimensional multislice spiral computed tomographic angiography (3D-MSCTA) is a minimally invasive method of vascular mapping. The aim of this study was to evaluate the clinical usefulness of this imaging technique in delineating the recipient vessels for safer free tissue transfer...... be kept in mind, especially inthe patients with peripheral vascular disease. 3D-MSCTA has the potential to replace digital subtraction angiography for planning of microvascular reconstructions and newer devices with higher resolutions will probably increase the reliability of this technique. (c) 2009...

  15. Determination of fat tissue area in the abdomen and evaluation of degree of obesity. Pt. 1. A unique application of a densitometric technique of computed tomography for CT values of fat tissue area

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Fumie [Saint Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

    1995-06-01

    Computed tomography (CT) scanning images were taken from 26 normal subjects, 23 obesity patients and 11 with leanness to determine fat tissue values. Setting three regions of interest (ROIs) for fat tissues identified by a double-window display, a total of 52 images were employed. Histograms were constructed for each of the 3 ROIs, and the maximum, mean and minimum values were computed for each fat tissues. Areas of entire fat tissues were computed on each image with the above-cited CT software for thyroidal iodine contents by setting ROIs along the outline of body, the abdominal wall and the wall of colon, respectively. Areas of subcutaneous fat tissues were calculated by simply subtracting the values of visceral fat tissues from those of entire fat tissues. Means of maximum and minimum CT values of visceral fat tissues on 52 images were -34.7 HU and -162.1 HU, respectively. The double-window display indicated that the spectrum of CT values of fat tissue included not only visceral and subcutaneous fat tissues but fecal materials with air bubbles in the colon. Areas of fecal materials with the same CT values as that of the fat tissues occupied 2.5{+-}3.0% of that of the visceral fat tissue. The areas of subcutaneous and visceral fat tissues were largest at the levels of -20 to 0 mm and 60 to 100 mm, respectively, on all images. At the level of 0 mm, the areas of visceral fat tissue did not show any differences among normal subjects, obesity patients and patients with leanness. It was concluded that the CT software is applicable to obtain satisfactory values for areas of visceral fat tissue, and that CT images at the levels of 0, 40, 60 and 100 mm are necessary to accurately determine areas of visceral fat tissues. (S.Y.).

  16. Determination of fat tissue area in the abdomen and evaluation of degree of obesity. Pt. 1. A unique application of a densitometric technique of computed tomography for CT values of fat tissue area

    International Nuclear Information System (INIS)

    Nakayama, Fumie

    1995-01-01

    Computed tomography (CT) scanning images were taken from 26 normal subjects, 23 obesity patients and 11 with leanness to determine fat tissue values. Setting three regions of interest (ROIs) for fat tissues identified by a double-window display, a total of 52 images were employed. Histograms were constructed for each of the 3 ROIs, and the maximum, mean and minimum values were computed for each fat tissues. Areas of entire fat tissues were computed on each image with the above-cited CT software for thyroidal iodine contents by setting ROIs along the outline of body, the abdominal wall and the wall of colon, respectively. Areas of subcutaneous fat tissues were calculated by simply subtracting the values of visceral fat tissues from those of entire fat tissues. Means of maximum and minimum CT values of visceral fat tissues on 52 images were -34.7 HU and -162.1 HU, respectively. The double-window display indicated that the spectrum of CT values of fat tissue included not only visceral and subcutaneous fat tissues but fecal materials with air bubbles in the colon. Areas of fecal materials with the same CT values as that of the fat tissues occupied 2.5±3.0% of that of the visceral fat tissue. The areas of subcutaneous and visceral fat tissues were largest at the levels of -20 to 0 mm and 60 to 100 mm, respectively, on all images. At the level of 0 mm, the areas of visceral fat tissue did not show any differences among normal subjects, obesity patients and patients with leanness. It was concluded that the CT software is applicable to obtain satisfactory values for areas of visceral fat tissue, and that CT images at the levels of 0, 40, 60 and 100 mm are necessary to accurately determine areas of visceral fat tissues. (S.Y.)

  17. Recent advances in swarm intelligence and evolutionary computation

    CERN Document Server

    2015-01-01

    This timely review volume summarizes the state-of-the-art developments in nature-inspired algorithms and applications with the emphasis on swarm intelligence and bio-inspired computation. Topics include the analysis and overview of swarm intelligence and evolutionary computation, hybrid metaheuristic algorithms, bat algorithm, discrete cuckoo search, firefly algorithm, particle swarm optimization, and harmony search as well as convergent hybridization. Application case studies have focused on the dehydration of fruits and vegetables by the firefly algorithm and goal programming, feature selection by the binary flower pollination algorithm, job shop scheduling, single row facility layout optimization, training of feed-forward neural networks, damage and stiffness identification, synthesis of cross-ambiguity functions by the bat algorithm, web document clustering, truss analysis, water distribution networks, sustainable building designs and others. As a timely review, this book can serve as an ideal reference f...

  18. Nature-inspired computing and optimization theory and applications

    CERN Document Server

    Yang, Xin-She; Nakamatsu, Kazumi

    2017-01-01

    The book provides readers with a snapshot of the state of the art in the field of nature-inspired computing and its application in optimization. The approach is mainly practice-oriented: each bio-inspired technique or algorithm is introduced together with one of its possible applications. Applications cover a wide range of real-world optimization problems: from feature selection and image enhancement to scheduling and dynamic resource management, from wireless sensor networks and wiring network diagnosis to sports training planning and gene expression, from topology control and morphological filters to nutritional meal design and antenna array design. There are a few theoretical chapters comparing different existing techniques, exploring the advantages of nature-inspired computing over other methods, and investigating the mixing time of genetic algorithms. The book also introduces a wide range of algorithms, including the ant colony optimization, the bat algorithm, genetic algorithms, the collision-based opti...

  19. In vivo X-Ray Computed Tomographic Imaging of Soft Tissue with Native, Intravenous, or Oral Contrast

    Science.gov (United States)

    Wathen, Connor A.; Foje, Nathan; van Avermaete, Tony; Miramontes, Bernadette; Chapaman, Sarah E.; Sasser, Todd A.; Kannan, Raghuraman; Gerstler, Steven; Leevy, W. Matthew

    2013-01-01

    X-ray Computed Tomography (CT) is one of the most commonly utilized anatomical imaging modalities for both research and clinical purposes. CT combines high-resolution, three-dimensional data with relatively fast acquisition to provide a solid platform for non-invasive human or specimen imaging. The primary limitation of CT is its inability to distinguish many soft tissues based on native contrast. While bone has high contrast within a CT image due to its material density from calcium phosphate, soft tissue is less dense and many are homogenous in density. This presents a challenge in distinguishing one type of soft tissue from another. A couple exceptions include the lungs as well as fat, both of which have unique densities owing to the presence of air or bulk hydrocarbons, respectively. In order to facilitate X-ray CT imaging of other structures, a range of contrast agents have been developed to selectively identify and visualize the anatomical properties of individual tissues. Most agents incorporate atoms like iodine, gold, or barium because of their ability to absorb X-rays, and thus impart contrast to a given organ system. Here we review the strategies available to visualize lung, fat, brain, kidney, liver, spleen, vasculature, gastrointestinal tract, and liver tissues of living mice using either innate contrast, or commercial injectable or ingestible agents with selective perfusion. Further, we demonstrate how each of these approaches will facilitate the non-invasive, longitudinal, in vivo imaging of pre-clinical disease models at each anatomical site. PMID:23711461

  20. Linking microscopic spatial patterns of tissue destruction in emphysema to macroscopic decline in stiffness using a 3D computational model.

    Directory of Open Access Journals (Sweden)

    Harikrishnan Parameswaran

    2011-04-01

    Full Text Available Pulmonary emphysema is a connective tissue disease characterized by the progressive destruction of alveolar walls leading to airspace enlargement and decreased elastic recoil of the lung. However, the relationship between microscopic tissue structure and decline in stiffness of the lung is not well understood. In this study, we developed a 3D computational model of lung tissue in which a pre-strained cuboidal block of tissue was represented by a tessellation of space filling polyhedra, with each polyhedral unit-cell representing an alveolus. Destruction of alveolar walls was mimicked by eliminating faces that separate two polyhedral either randomly or in a spatially correlated manner, in which the highest force bearing walls were removed at each step. Simulations were carried out to establish a link between the geometries that emerged and the rate of decline in bulk modulus of the tissue block. The spatially correlated process set up by the force-based destruction lead to a significantly faster rate of decline in bulk modulus accompanied by highly heterogeneous structures than the random destruction pattern. Using the Karhunen-Loève transformation, an estimator of the change in bulk modulus from the first four moments of airspace cell volumes was setup. Simulations were then obtained for tissue destruction with different idealized alveolar geometry, levels of pre-strain, linear and nonlinear elasticity assumptions for alveolar walls and also mixed destruction patterns where both random and force-based destruction occurs simultaneously. In all these cases, the change in bulk modulus from cell volumes was accurately estimated. We conclude that microscopic structural changes in emphysema and the associated decline in tissue stiffness are linked by the spatial pattern of the destruction process.

  1. Journal of Clinical Monitoring and Computing 2015 end of year summary : tissue oxygenation and microcirculation

    NARCIS (Netherlands)

    Scheeren, T W L

    Last year we started this series of end of year summaries of papers published in the 2014 issues of the Journal Of Clinical Monitoring And Computing with a review on near infrared spectroscopy (Scheeren et al. in J Clin Monit Comput 29(2):217-220, 2015). This year we will broaden the scope and

  2. Quantization of liver tissue in dual kVp computed tomography using linear discriminant analysis

    Science.gov (United States)

    Tkaczyk, J. Eric; Langan, David; Wu, Xiaoye; Xu, Daniel; Benson, Thomas; Pack, Jed D.; Schmitz, Andrea; Hara, Amy; Palicek, William; Licato, Paul; Leverentz, Jaynne

    2009-02-01

    Linear discriminate analysis (LDA) is applied to dual kVp CT and used for tissue characterization. The potential to quantitatively model both malignant and benign, hypo-intense liver lesions is evaluated by analysis of portal-phase, intravenous CT scan data obtained on human patients. Masses with an a priori classification are mapped to a distribution of points in basis material space. The degree of localization of tissue types in the material basis space is related to both quantum noise and real compositional differences. The density maps are analyzed with LDA and studied with system simulations to differentiate these factors. The discriminant analysis is formulated so as to incorporate the known statistical properties of the data. Effective kVp separation and mAs relates to precision of tissue localization. Bias in the material position is related to the degree of X-ray scatter and partial-volume effect. Experimental data and simulations demonstrate that for single energy (HU) imaging or image-based decomposition pixel values of water-like tissues depend on proximity to other iodine-filled bodies. Beam-hardening errors cause a shift in image value on the scale of that difference sought between in cancerous and cystic lessons. In contrast, projection-based decomposition or its equivalent when implemented on a carefully calibrated system can provide accurate data. On such a system, LDA may provide novel quantitative capabilities for tissue characterization in dual energy CT.

  3. Cyclic deformation-induced solute transport in tissue scaffolds with computer designed, interconnected, pore networks: experiments and simulations.

    Science.gov (United States)

    Den Buijs, Jorn Op; Dragomir-Daescu, Dan; Ritman, Erik L

    2009-08-01

    Nutrient supply and waste removal in porous tissue engineering scaffolds decrease from the periphery to the center, leading to limited depth of ingrowth of new tissue into the scaffold. However, as many tissues experience cyclic physiological strains, this may provide a mechanism to enhance solute transport in vivo before vascularization of the scaffold. The hypothesis of this study was that pore cross-sectional geometry and interconnectivity are of major importance for the effectiveness of cyclic deformation-induced solute transport. Transparent elastic polyurethane scaffolds, with computer-programmed design of pore networks in the form of interconnected channels, were fabricated using a 3D printing and injection molding technique. The scaffold pores were loaded with a colored tracer for optical contrast, cyclically compressed with deformations of 10 and 15% of the original undeformed height at 1.0 Hz. Digital imaging was used to quantify the spatial distribution of the tracer concentration within the pores. Numerical simulations of a fluid-structure interaction model of deformation-induced solute transport were compared to the experimental data. The results of experiments and modeling agreed well and showed that pore interconnectivity heavily influences deformation-induced solute transport. Pore cross-sectional geometry appears to be of less relative importance in interconnected pore networks. Validated computer models of solute transport can be used to design optimal scaffold pore geometries that will enhance the convective transport of nutrients inside the scaffold and the removal of waste, thus improving the cell survivability deep inside the scaffold.

  4. Medical imaging in clinical applications algorithmic and computer-based approaches

    CERN Document Server

    Bhateja, Vikrant; Hassanien, Aboul

    2016-01-01

    This volume comprises of 21 selected chapters, including two overview chapters devoted to abdominal imaging in clinical applications supported computer aided diagnosis approaches as well as different techniques for solving the pectoral muscle extraction problem in the preprocessing part of the CAD systems for detecting breast cancer in its early stage using digital mammograms. The aim of this book is to stimulate further research in medical imaging applications based algorithmic and computer based approaches and utilize them in real-world clinical applications. The book is divided into four parts, Part-I: Clinical Applications of Medical Imaging, Part-II: Classification and clustering, Part-III: Computer Aided Diagnosis (CAD) Tools and Case Studies and Part-IV: Bio-inspiring based Computer Aided diagnosis techniques. .

  5. Impact of Computed Tomography Image Quality on Image-Guided Radiation Therapy Based on Soft Tissue Registration

    International Nuclear Information System (INIS)

    Morrow, Natalya V.; Lawton, Colleen A.; Qi, X. Sharon; Li, X. Allen

    2012-01-01

    Purpose: In image-guided radiation therapy (IGRT), different computed tomography (CT) modalities with varying image quality are being used to correct for interfractional variations in patient set-up and anatomy changes, thereby reducing clinical target volume to the planning target volume (CTV-to-PTV) margins. We explore how CT image quality affects patient repositioning and CTV-to-PTV margins in soft tissue registration-based IGRT for prostate cancer patients. Methods and Materials: Four CT-based IGRT modalities used for prostate RT were considered in this study: MV fan beam CT (MVFBCT) (Tomotherapy), MV cone beam CT (MVCBCT) (MVision; Siemens), kV fan beam CT (kVFBCT) (CTVision, Siemens), and kV cone beam CT (kVCBCT) (Synergy; Elekta). Daily shifts were determined by manual registration to achieve the best soft tissue agreement. Effect of image quality on patient repositioning was determined by statistical analysis of daily shifts for 136 patients (34 per modality). Inter- and intraobserver variability of soft tissue registration was evaluated based on the registration of a representative scan for each CT modality with its corresponding planning scan. Results: Superior image quality with the kVFBCT resulted in reduced uncertainty in soft tissue registration during IGRT compared with other image modalities for IGRT. The largest interobserver variations of soft tissue registration were 1.1 mm, 2.5 mm, 2.6 mm, and 3.2 mm for kVFBCT, kVCBCT, MVFBCT, and MVCBCT, respectively. Conclusions: Image quality adversely affects the reproducibility of soft tissue-based registration for IGRT and necessitates a careful consideration of residual uncertainties in determining different CTV-to-PTV margins for IGRT using different image modalities.

  6. Pairing experimentation and computational modelling to understand the role of tissue inducer cells in the development of lymphoid organs

    Directory of Open Access Journals (Sweden)

    Kieran eAlden

    2012-07-01

    Full Text Available The use of genetic tools, imaging technologies and ex vivo culture systems has provided significant insights into the role of tissue inducer cells and associated signalling pathways in the formation and function of lymphoid organs. Despite advances in experimental technologies, the molecular and cellular process orchestrating the formation of a complex 3-dimensional tissue is difficult to dissect using current approaches. Therefore, a robust set of simulation tools have been developed to model the processes involved in lymphoid tissue development. Specifically the role of different tissue inducer cell populations in the dynamic formation of Peyer's Patches has been examined. Utilising approaches from critical systems engineering an unbiased model of lymphoid tissue inducer cell function has been developed, that permits the development of emerging behaviours that are statistically not different from that observed in vivo. These results provide the confidence to utilise statistical methods to explore how the simulator predicts cellular behaviour and outcomes under different physiological conditions. Such methods, known as sensitivity analysis techniques, can provide insight into when a component part of the system (such as a particular cell type, adhesion molecule, or chemokine begins to have an influence on observed behaviour, and quantifies the effect a component part has on the end result: the formation of lymphoid tissue. Through use of such a principled approach in the design, calibration, and analysis of a computer simulation, a robust in silico tool can be developed which can both further the understanding of a biological system being explored, and act as a tool for the generation of hypotheses which can be tested utilising experimental approaches.

  7. Impact of Computed Tomography Image Quality on Image-Guided Radiation Therapy Based on Soft Tissue Registration

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, Natalya V.; Lawton, Colleen A. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Qi, X. Sharon [Department of Radiation Oncology, University of Colorado Denver, Denver, Colorado (United States); Li, X. Allen, E-mail: ali@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)

    2012-04-01

    Purpose: In image-guided radiation therapy (IGRT), different computed tomography (CT) modalities with varying image quality are being used to correct for interfractional variations in patient set-up and anatomy changes, thereby reducing clinical target volume to the planning target volume (CTV-to-PTV) margins. We explore how CT image quality affects patient repositioning and CTV-to-PTV margins in soft tissue registration-based IGRT for prostate cancer patients. Methods and Materials: Four CT-based IGRT modalities used for prostate RT were considered in this study: MV fan beam CT (MVFBCT) (Tomotherapy), MV cone beam CT (MVCBCT) (MVision; Siemens), kV fan beam CT (kVFBCT) (CTVision, Siemens), and kV cone beam CT (kVCBCT) (Synergy; Elekta). Daily shifts were determined by manual registration to achieve the best soft tissue agreement. Effect of image quality on patient repositioning was determined by statistical analysis of daily shifts for 136 patients (34 per modality). Inter- and intraobserver variability of soft tissue registration was evaluated based on the registration of a representative scan for each CT modality with its corresponding planning scan. Results: Superior image quality with the kVFBCT resulted in reduced uncertainty in soft tissue registration during IGRT compared with other image modalities for IGRT. The largest interobserver variations of soft tissue registration were 1.1 mm, 2.5 mm, 2.6 mm, and 3.2 mm for kVFBCT, kVCBCT, MVFBCT, and MVCBCT, respectively. Conclusions: Image quality adversely affects the reproducibility of soft tissue-based registration for IGRT and necessitates a careful consideration of residual uncertainties in determining different CTV-to-PTV margins for IGRT using different image modalities.

  8. Determination of a tissue-level failure evaluation standard for rat femoral cortical bone utilizing a hybrid computational-experimental method.

    Science.gov (United States)

    Fan, Ruoxun; Liu, Jie; Jia, Zhengbin; Deng, Ying; Liu, Jun

    2018-01-01

    Macro-level failure in bone structure could be diagnosed by pain or physical examination. However, diagnosing tissue-level failure in a timely manner is challenging due to the difficulty in observing the interior mechanical environment of bone tissue. Because most fractures begin with tissue-level failure in bone tissue caused by continually applied loading, people attempt to monitor the tissue-level failure of bone and provide corresponding measures to prevent fracture. Many tissue-level mechanical parameters of bone could be predicted or measured; however, the value of the parameter may vary among different specimens belonging to a kind of bone structure even at the same age and anatomical site. These variations cause difficulty in representing tissue-level bone failure. Therefore, determining an appropriate tissue-level failure evaluation standard is necessary to represent tissue-level bone failure. In this study, the yield and failure processes of rat femoral cortical bones were primarily simulated through a hybrid computational-experimental method. Subsequently, the tissue-level strains and the ratio between tissue-level failure and yield strains in cortical bones were predicted. The results indicated that certain differences existed in tissue-level strains; however, slight variations in the ratio were observed among different cortical bones. Therefore, the ratio between tissue-level failure and yield strains for a kind of bone structure could be determined. This ratio may then be regarded as an appropriate tissue-level failure evaluation standard to represent the mechanical status of bone tissue.

  9. Cell-biomaterial mechanical interaction in the framework of tissue engineering: insights, computational modeling and perspectives.

    Science.gov (United States)

    Sanz-Herrera, Jose A; Reina-Romo, Esther

    2011-01-01

    Tissue engineering is an emerging field of research which combines the use of cell-seeded biomaterials both in vitro and/or in vivo with the aim of promoting new tissue formation or regeneration. In this context, how cells colonize and interact with the biomaterial is critical in order to get a functional tissue engineering product. Cell-biomaterial interaction is referred to here as the phenomenon involved in adherent cells attachment to the biomaterial surface, and their related cell functions such as growth, differentiation, migration or apoptosis. This process is inherently complex in nature involving many physico-chemical events which take place at different scales ranging from molecular to cell body (organelle) levels. Moreover, it has been demonstrated that the mechanical environment at the cell-biomaterial location may play an important role in the subsequent cell function, which remains to be elucidated. In this paper, the state-of-the-art research in the physics and mechanics of cell-biomaterial interaction is reviewed with an emphasis on focal adhesions. The paper is focused on the different models developed at different scales available to simulate certain features of cell-biomaterial interaction. A proper understanding of cell-biomaterial interaction, as well as the development of predictive models in this sense, may add some light in tissue engineering and regenerative medicine fields.

  10. Nonlinear ultrasound propagation through layered liquid and tissue-equivalent media: computational and experimental results at high frequency

    International Nuclear Information System (INIS)

    Williams, Ross; Cherin, Emmanuel; Lam, Toby Y J; Tavakkoli, Jahangir; Zemp, Roger J; Foster, F Stuart

    2006-01-01

    Nonlinear propagation has been demonstrated to have a significant impact on ultrasound imaging. An efficient computational algorithm is presented to simulate nonlinear ultrasound propagation through layered liquid and tissue-equivalent media. Results are compared with hydrophone measurements. This study was undertaken to investigate the role of nonlinear propagation in high frequency ultrasound micro-imaging. The acoustic field of a focused transducer (20 MHz centre frequency, f-number 2.5) was simulated for layered media consisting of water and tissue-mimicking phantom, for several wide-bandwidth source pulses. The simulation model accounted for the effects of diffraction, attenuation and nonlinearity, with transmission and refraction at layer boundaries. The parameter of nonlinearity, B/A, of the water and tissue-mimicking phantom were assumed to be 5.2 and 7.4, respectively. The experimentally measured phantom B/A value found using a finite-amplitude insert-substitution method was shown to be 7.4 ± 0.6. Relative amounts of measured second and third harmonic pressures as a function of the fundamental pressures at the focus were in good agreement with simulations. Agreement within 3% was found between measurements and simulations of the beam widths of the fundamental and second harmonic signals following propagation through the tissue phantom. The results demonstrate significant nonlinear propagation effects for high frequency imaging beams

  11. Three-dimensional reconstruction of colorectal tumors from serial tissue sections by computer graphics: a preliminary study.

    Science.gov (United States)

    Kikuchi, S; Matsuzaki, H; Kondo, K; Ohtani, Y; Ihara, A; Hiki, Y; Kakita, A; Kuwao, S

    2000-01-01

    We present herein the three-dimensional reconstruction of colorectal tumors, with particular reference to growth pattern into each layer of the colorectal wall, and measurement of tumor volume and surface area. Conventional tissue section images of colorectal tumors were analyzed using a computer graphics analysis program. The two-dimensional extent of invasion by each tumor into each layer of intestinal wall were determined from the images of each section. Based on data from multiple sections, tumor and surrounding normal tissue layers were reconstructed three-dimensionally, and volume and surface area of the tumors were determined. Using this technique, three-dimensional morphology of tumor and tumor progression into colorectal wall could be determined. Volume and surface area of the colon tumor were 4871 mm3 and 1741 mm2, respectively. Volume and surface area of the rectal tumor were 1090 mm3 and 877 mm2, respectively. This technique may provide a new approach for pathological analysis of colorectal carcinoma.

  12. Advances in neural networks computational and theoretical issues

    CERN Document Server

    Esposito, Anna; Morabito, Francesco

    2015-01-01

    This book collects research works that exploit neural networks and machine learning techniques from a multidisciplinary perspective. Subjects covered include theoretical, methodological and computational topics which are grouped together into chapters devoted to the discussion of novelties and innovations related to the field of Artificial Neural Networks as well as the use of neural networks for applications, pattern recognition, signal processing, and special topics such as the detection and recognition of multimodal emotional expressions and daily cognitive functions, and  bio-inspired memristor-based networks.  Providing insights into the latest research interest from a pool of international experts coming from different research fields, the volume becomes valuable to all those with any interest in a holistic approach to implement believable, autonomous, adaptive, and context-aware Information Communication Technologies.

  13. In vivo X-Ray Computed Tomographic Imaging of Soft Tissue with Native, Intravenous, or Oral Contrast

    Directory of Open Access Journals (Sweden)

    W. Matthew Leevy

    2013-05-01

    Full Text Available X-ray Computed Tomography (CT is one of the most commonly utilized anatomical imaging modalities for both research and clinical purposes. CT combines high-resolution, three-dimensional data with relatively fast acquisition to provide a solid platform for non-invasive human or specimen imaging. The primary limitation of CT is its inability to distinguish many soft tissues based on native contrast. While bone has high contrast within a CT image due to its material density from calcium phosphate, soft tissue is less dense and many are homogenous in density. This presents a challenge in distinguishing one type of soft tissue from another. A couple exceptions include the lungs as well as fat, both of which have unique densities owing to the presence of air or bulk hydrocarbons, respectively. In order to facilitate X-ray CT imaging of other structures, a range of contrast agents have been developed to selectively identify and visualize the anatomical properties of individual tissues. Most agents incorporate atoms like iodine, gold, or barium because of their ability to absorb X-rays, and thus impart contrast to a given organ system. Here we review the strategies available to visualize lung, fat, brain, kidney, liver, spleen, vasculature, gastrointestinal tract, and liver tissues of living mice using either innate contrast, or commercial injectable or ingestible agents with selective perfusion. Further, we demonstrate how each of these approaches will facilitate the non-invasive, longitudinal, in vivo imaging of pre-clinical disease models at each anatomical site.

  14. A Computational, Tissue-Realistic Model of Pressure Ulcer Formation in Individuals with Spinal Cord Injury.

    Directory of Open Access Journals (Sweden)

    Cordelia Ziraldo

    2015-06-01

    Full Text Available People with spinal cord injury (SCI are predisposed to pressure ulcers (PU. PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM of ischemia/reperfusion-induced inflammation and PU (the PUABM was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to "better" vs. "worse" outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU.

  15. A Computational, Tissue-Realistic Model of Pressure Ulcer Formation in Individuals with Spinal Cord Injury.

    Science.gov (United States)

    Ziraldo, Cordelia; Solovyev, Alexey; Allegretti, Ana; Krishnan, Shilpa; Henzel, M Kristi; Sowa, Gwendolyn A; Brienza, David; An, Gary; Mi, Qi; Vodovotz, Yoram

    2015-06-01

    People with spinal cord injury (SCI) are predisposed to pressure ulcers (PU). PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM) of ischemia/reperfusion-induced inflammation and PU (the PUABM) was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to "better" vs. "worse" outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs) suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU.

  16. A Computational, Tissue-Realistic Model of Pressure Ulcer Formation in Individuals with Spinal Cord Injury

    Science.gov (United States)

    Ziraldo, Cordelia; Solovyev, Alexey; Allegretti, Ana; Krishnan, Shilpa; Henzel, M. Kristi; Sowa, Gwendolyn A.; Brienza, David; An, Gary; Mi, Qi; Vodovotz, Yoram

    2015-01-01

    People with spinal cord injury (SCI) are predisposed to pressure ulcers (PU). PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM) of ischemia/reperfusion-induced inflammation and PU (the PUABM) was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to “better” vs. “worse” outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs) suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU. PMID:26111346

  17. Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography

    Science.gov (United States)

    Walton, Lucy A.; Bradley, Robert S.; Withers, Philip J.; Newton, Victoria L.; Watson, Rachel E. B.; Austin, Clare; Sherratt, Michael J.

    2015-05-01

    Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons.

  18. Computational cell quantification in the human brain tissues based on hard x-ray phase-contrast tomograms

    Science.gov (United States)

    Hieber, Simone E.; Bikis, Christos; Khimchenko, Anna; Schulz, Georg; Deyhle, Hans; Thalmann, Peter; Chicherova, Natalia; Rack, Alexander; Zdora, Marie-Christine; Zanette, Irene; Schweighauser, Gabriel; Hench, Jürgen; Müller, Bert

    2016-10-01

    Cell visualization and counting plays a crucial role in biological and medical research including the study of neurodegenerative diseases. The neuronal cell loss is typically determined to measure the extent of the disease. Its characterization is challenging because the cell density and size already differs by more than three orders of magnitude in a healthy cerebellum. Cell visualization is commonly performed by histology and fluorescence microscopy. These techniques are limited to resolve complex microstructures in the third dimension. Phase- contrast tomography has been proven to provide sufficient contrast in the three-dimensional imaging of soft tissue down to the cell level and, therefore, offers the basis for the three-dimensional segmentation. Within this context, a human cerebellum sample was embedded in paraffin and measured in local phase-contrast mode at the beamline ID19 (ESRF, Grenoble, France) and the Diamond Manchester Imaging Branchline I13-2 (Diamond Light Source, Didcot, UK). After the application of Frangi-based filtering the data showed sufficient contrast to automatically identify the Purkinje cells and to quantify their density to 177 cells per mm3 within the volume of interest. Moreover, brain layers were segmented in a region of interest based on edge detection. Subsequently performed histological analysis validated the presence of the cells, which required a mapping from the two- dimensional histological slices to the three-dimensional tomogram. The methodology can also be applied to further tissue types and shows potential for the computational tissue analysis in health and disease.

  19. Percutaneous computed tomography-guided core needle biopsy of soft tissue tumors: results and correlation with surgical specimen analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chojniak, Rubens; Grigio, Henrique Ramos; Bitencourt, Almir Galvao Vieira; Pinto, Paula Nicole Vieira; Tyng, Chiang J.; Cunha, Isabela Werneck da; Aguiar Junior, Samuel; Lopes, Ademar, E-mail: chojniak@uol.com.br [Hospital A.C. Camargo, Sao Paulo, SP (Brazil)

    2012-09-15

    Objective: To evaluate the efficacy of percutaneous computed tomography (CT)-guided core needle biopsy of soft tissue tumors in obtaining appropriate samples for histological analysis, and compare its diagnosis with the results of the surgical pathology as available. Materials and Methods: The authors reviewed medical records, imaging and histological reports of 262 patients with soft-tissue tumors submitted to CT-guided core needle biopsy in an oncologic reference center between 2003 and 2009. Results: Appropriate samples were obtained in 215 (82.1%) out of the 262 patients. The most prevalent tumors were sarcomas (38.6%), metastatic carcinomas (28.8%), benign mesenchymal tumors (20.5%) and lymphomas (9.3%). Histological grading was feasible in 92.8% of sarcoma patients, with the majority of them (77.9%) being classified as high grade tumors. Out of the total sample, 116 patients (44.3%) underwent surgical excision and diagnosis confirmation. Core biopsy demonstrated 94.6% accuracy in the identification of sarcomas, with 96.4% sensitivity and 89.5% specificity. A significant intermethod agreement about histological grading was observed between core biopsy and surgical resection (p < 0.001; kappa = 0.75). Conclusion: CT-guided core needle biopsy demonstrated a high diagnostic accuracy in the evaluation of soft tissue tumors as well as in the histological grading of sarcomas, allowing an appropriate therapeutic planning (author)

  20. 16th International Conference on Hybrid Intelligent Systems and the 8th World Congress on Nature and Biologically Inspired Computing

    CERN Document Server

    Haqiq, Abdelkrim; Alimi, Adel; Mezzour, Ghita; Rokbani, Nizar; Muda, Azah

    2017-01-01

    This book presents the latest research in hybrid intelligent systems. It includes 57 carefully selected papers from the 16th International Conference on Hybrid Intelligent Systems (HIS 2016) and the 8th World Congress on Nature and Biologically Inspired Computing (NaBIC 2016), held on November 21–23, 2016 in Marrakech, Morocco. HIS - NaBIC 2016 was jointly organized by the Machine Intelligence Research Labs (MIR Labs), USA; Hassan 1st University, Settat, Morocco and University of Sfax, Tunisia. Hybridization of intelligent systems is a promising research field in modern artificial/computational intelligence and is concerned with the development of the next generation of intelligent systems. The conference’s main aim is to inspire further exploration of the intriguing potential of hybrid intelligent systems and bio-inspired computing. As such, the book is a valuable resource for practicing engineers /scientists and researchers working in the field of computational intelligence and artificial intelligence.

  1. The nutrition of the human meniscus: A computational analysis investigating the effect of vascular recession on tissue homeostasis.

    Science.gov (United States)

    Travascio, Francesco; Jackson, Alicia R

    2017-08-16

    The meniscus is essential to the functioning of the knee, offering load support, congruency, lubrication, and protection to the underlying cartilage. Meniscus degeneration affects ∼35% of the population, and potentially leads to knee osteoarthritis. The etiology of meniscal degeneration remains to be elucidated, although many factors have been considered. However, the role of nutritional supply to meniscus cells in the pathogenesis of meniscus degeneration has been so far overlooked. Nutrients are delivered to meniscal cells through the surrounding synovial fluid and the blood vessels present in the outer region of the meniscus. During maturation, vascularization progressively recedes up to the outer 10% of the tissue, leaving the majority avascular. It has been hypothesized that vascular recession might significantly reduce the nutrient supply to cells, thus contributing to meniscus degeneration. The objective of this study was to evaluate the effect of vascular recession on nutrient levels available to meniscus cells. This was done by developing a novel computational model for meniscus homeostasis based on mixture theory. It was found that transvascular transport of nutrients in the vascularized region of the meniscus contributes to more than 40% of the glucose content in the core of the tissue. However, vascular recession does not significantly alter nutrient levels in the meniscus, reducing at most 5% of the nutrient content in the central portion of the tissue. Therefore, our analysis suggests that reduced vascularity is not likely a primary initiating source in tissue degeneration. However, it does feasibly play a key role in inability for self-repair, as seen clinically. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Response functions for computing absorbed dose to skeletal tissues from photon irradiation-an update

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Perry B; Bahadori, Amir A [Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Eckerman, Keith F [Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Lee, Choonsik [Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892 (United States); Bolch, Wesley E, E-mail: wbolch@ufl.edu [Nuclear and Radiological/Biomedical Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2011-04-21

    A comprehensive set of photon fluence-to-dose response functions (DRFs) is presented for two radiosensitive skeletal tissues-active and total shallow marrow-within 15 and 32 bone sites, respectively, of the ICRP reference adult male. The functions were developed using fractional skeletal masses and associated electron-absorbed fractions as reported for the UF hybrid adult male phantom, which in turn is based upon micro-CT images of trabecular spongiosa taken from a 40 year male cadaver. The new DRFs expand upon both the original set of seven functions produced in 1985, and a 2007 update calculated under the assumption of secondary electron escape from spongiosa. In this study, it is assumed that photon irradiation of the skeleton will yield charged particle equilibrium across all spongiosa regions at energies exceeding 200 keV. Kerma coefficients for active marrow, inactive marrow, trabecular bone and spongiosa at higher energies are calculated using the DRF algorithm setting the electron-absorbed fraction for self-irradiation to unity. By comparing kerma coefficients and DRF functions, dose enhancement factors and mass energy-absorption coefficient (MEAC) ratios for active marrow to spongiosa were derived. These MEAC ratios compared well with those provided by the NIST Physical Reference Data Library (mean difference of 0.8%), and the dose enhancement factors for active marrow compared favorably with values calculated in the well-known study published by King and Spiers (1985 Br. J. Radiol. 58 345-56) (mean absolute difference of 1.9 percentage points). Additionally, dose enhancement factors for active marrow were shown to correlate well with the shallow marrow volume fraction (R{sup 2} = 0.91). Dose enhancement factors for the total shallow marrow were also calculated for 32 bone sites representing the first such derivation for this target tissue.

  3. Advanced computer techniques for inverse modeling of electric current in cardiac tissue

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, S.A.; Romero, L.A.; Diegert, C.F.

    1996-08-01

    For many years, ECG`s and vector cardiograms have been the tools of choice for non-invasive diagnosis of cardiac conduction problems, such as found in reentrant tachycardia or Wolff-Parkinson-White (WPW) syndrome. Through skillful analysis of these skin-surface measurements of cardiac generated electric currents, a physician can deduce the general location of heart conduction irregularities. Using a combination of high-fidelity geometry modeling, advanced mathematical algorithms and massively parallel computing, Sandia`s approach would provide much more accurate information and thus allow the physician to pinpoint the source of an arrhythmia or abnormal conduction pathway.

  4. Methods and compositions for protection of cells and tissues from computed tomography radiation

    Energy Technology Data Exchange (ETDEWEB)

    Grdina, David J.

    2018-01-30

    Described are methods for preventing or inhibiting genomic instability and in cells affected by diagnostic radiology procedures employing ionizing radiation. Embodiments include methods of preventing or inhibiting genomic instability and in cells affected by computed tomography (CT) radiation. Subjects receiving ionizing radiation may be those persons suspected of having cancer, or cancer patients having received or currently receiving cancer therapy, and or those patients having received previous ionizing radiation, including those who are approaching or have exceeded the recommended total radiation dose for a person.

  5. ASSESSMENT OF BONE TISSUE CONDITION BY METHOD OF COMPUTED TOMOGRAPHY IN PTS WITH RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    T A Raskina

    2002-01-01

    Full Text Available Aim: To estimate the bone mineral density (BMD in patients with dilVerent variants of rheumatoid arthritis (RA. Materials and methods: The study included 65 patients with the acknowledged RA, who were not treated with corticosteroids, basic remedies and antiosteoporosis therapies. The group comprises 26 women оГ reproductive age (I group and 28 women in postmenopause period. The investigations were held with the computer tomograph “Tomoscan” Philips. Results: The comparative analysis of BMD disorders frequency in the studied groups shows that in RA women of postmenopause period osteopenia accounts for 57,1%, osteoporosis - for 32,1% of patients, which is twice as often as in premenopausal women period: 30,8% and 15,4% respectively. BMD levels in RA are correlated with rheumatoid lactor, destructive tendency in bones and high activity of disease.

  6. Contrast Agent-Enhanced Computed Tomography of Articular Cartilage: Association with Tissue Composition and Properties

    International Nuclear Information System (INIS)

    Silvast, T. S.; Jurvelin, J.S.; Aula, A.S.; Lammi, M.J.; Toeyraes, J.

    2009-01-01

    Background: Contrast agent-enhanced computed tomography may enable the noninvasive quantification of glycosaminoglycan (GAG) content of articular cartilage. It has been reported that penetration of the negatively charged contrast agent ioxaglate (Hexabrix) increases significantly after enzymatic degradation of GAGs. However, it is not known whether spontaneous degradation of articular cartilage can be quantitatively detected with this technique. Purpose: To investigate the diagnostic potential of contrast agent-enhanced cartilage tomography (CECT) in quantification of GAG concentration in normal and spontaneously degenerated articular cartilage by means of clinical peripheral quantitative computed tomography (pQCT). Material and Methods: In this in vitro study, normal and spontaneously degenerated adult bovine cartilage (n=32) was used. Bovine patellar cartilage samples were immersed in 21 mM contrast agent (Hexabrix) solution for 24 hours at room temperature. After immersion, the samples were scanned with a clinical pQCT instrument. From pQCT images, the contrast agent concentration in superficial as well as in full-thickness cartilage was calculated. Histological and functional integrity of the samples was quantified with histochemical and mechanical reference measurements extracted from our earlier study. Results: Full diffusion of contrast agent into the deep cartilage was found to take over 8 hours. As compared to normal cartilage, a significant increase (11%, P 0.5, P<0.01). Further, pQCT could be used to measure the thickness of patellar cartilage. Conclusion: The present results suggest that CECT can be used to diagnose proteoglycan depletion in spontaneously degenerated articular cartilage with a clinical pQCT scanner. Possibly, the in vivo use of clinical pQCT for CECT arthrography of human joints is feasible

  7. Optical coherence tomography (OCT) imaging and computer aided diagnosis of human cervical tissue specimens

    Science.gov (United States)

    Bazant-Hegemark, F.; Stone, N.; Read, M. D.; McCarthy, K.; Wang, R. K.

    2007-07-01

    The keyword for management of cervical cancer is prevention. The present program within the UK, the 'National Health Service (NHS) cervical screening programme' (NHSCSP), is based on cytology. Although the program has reduced the incidence of cervical cancer, this program requires patient follow ups and relies on diagnostic biopsying. There is potential for reducing costs and workload within the NHS, and relieving anxiety of patients. In this study, Optical Coherence Tomography (OCT) was investigated for its capability to improve this situation. Our time domain bench top system used a superluminescent diode (Superlum), centre wave length ~1.3 μm, resolution (air) ~15 μm. Tissue samples were obtained according to the ethics approval by Gloucestershire LREC, Nr. 05/Q2005/123. 1387 images of 199 participants have been compared with histopathology results and categorized accordingly. Our OCT images do not reach the clarity and resolution of histopathology. Further, establishing and recognizing features of diagnostic significance seems difficult. Automated classification would allow one to take decision-making to move from the subjective appraisal of a physician to an objective assessment. Hence we investigated a classification algorithm for its ability in recognizing pre-cancerous stages from OCT images. The initial results show promise.

  8. The effect of irradiation on the subcutaneous fatty layer and the perirectal tissue by computed tomography

    International Nuclear Information System (INIS)

    Komatsu, Takashi

    1987-01-01

    Although it has been suggested that the subcutaneous fatty layer is affected by irradiation, the available reports have not been able to find out yet. While, it is reported that the intrapelvic fat increases in volume after whole pelvic irradiation. This paper report a study about the effect of irradiation on subcutaneous fatty layer and intrapelvic fat. The subjects studied were 20 cases treated by whole pelvic irradiation. The x-ray CT film was used to measure the subcutaneous fatty layer and the intrapelvic fat. Three slices, the lower end of sacro-iliac joint, upper end of the femoral head and upper rim of the pubic symphysis, were chosen as the cross section level, and the thickness of subcutaneous fatty layer on 6 points of the body and the presacral space (PS) were measured. Irradiation group was followed by measuring the thickness of fatty layer; before irradiation, 1 month, 3 or 4 months, 6 or 7 months and 12 months after irradiation. At the three of four points, which are included within the irradiation area, the thickness of subcutaneous fatty layer tended to increase after irradiation, though it showed increase or decrease at each period. This tendency was prominent at the lower than the upper slice of the pelvis. The other points, which are out of the irradiation field, showed no significant change and some of them even showed the tendency of decrease. Fatty layer of the presacral space tended to increase following irradiation, but there was no correlation with the irradiation dose. It is considered that the injury of subcutaneous tissue by irradiation results in the disturbance of blood flow and then it accelerates deposition of fat to the irradiated area. (author)

  9. Computational and Experimental Insight Into Single-Molecule Piezoelectric Materials

    Science.gov (United States)

    Marvin, Christopher Wayne

    Piezoelectric materials allow for the harvesting of ambient waste energy from the environment. Producing lightweight, highly responsive materials is a challenge for this type of material, requiring polymer, foam, or bio-inspired materials. In this dissertation, I explore the origin of the piezoelectric effect in single molecules through density functional theory (DFT), analyze the piezoresponse of bio-inspired peptidic materials through the use of atomic and piezoresponse force microscopy (AFM and PFM), and develop a novel class of materials combining flexible polyurethane foams and non-piezoelectric, polar dopants. For the DFT calculations, functional group, regiochemical, and heteroatom derivatives of [6]helicene were examined for their influence on the piezoelectric response. An aza[6]helicene derivative was found to have a piezoelectric response (108 pm/V) comparable to ceramics such as lead zirconium titanate (200+ pm/V). These computed materials have the possibility to compete with current field-leading piezomaterials such as lead zirconium titanate (PZT), zinc oxide (ZnO), and polyvinylidene difluoride (PVDF) and its derivatives. The use of AFM/PFM allows for the demonstration of the piezoelectric effect of the selfassembled monolayer (SAM) peptidic systems. Through PFM, the influence that the helicity and sequence of the peptide has on the overall response of the molecule can be analyzed. Finally, development of a novel class of piezoelectrics, the foam-based materials, expands the current understanding of the qualities required for a piezoelectric material from ceramic and rigid materials to more flexible, organic materials. Through the exploration of these novel types of piezoelectric materials, new design rules and figures of merit have been developed.

  10. Automatic quantitative micro-computed tomography evaluation of angiogenesis in an axially vascularized tissue-engineered bone construct.

    Science.gov (United States)

    Arkudas, Andreas; Beier, Justus Patrick; Pryymachuk, Galyna; Hoereth, Tobias; Bleiziffer, Oliver; Polykandriotis, Elias; Hess, Andreas; Gulle, Heinz; Horch, Raymund E; Kneser, Ulrich

    2010-12-01

    We invented an automatic observer-independent quantitative method to analyze vascularization using micro-computed tomography (CT) along with three-dimensional (3D) reconstruction in a tissue engineering model. An arteriovenous loop was created in the medial thigh of 30 rats and was placed in a particulated porous hydroxyapatite and beta-tricalcium phosphate matrix, filled with fibrin (10 mg/mL fibrinogen and 2 IU/mL thrombin) without (group A) or with (group B) application of fibrin-gel-immobilized angiogenetic growth factors vascular endothelial growth factor (VEGF¹⁶⁵) and basic fibroblast growth factor (bFGF). The explantation intervals were 2, 4, and 8 weeks. Specimens were investigated by means of micro-CT followed by an automatic 3D analysis, which was correlated to histomorphometrical findings. In both groups, the arteriovenous loop led to generation of dense vascularized connective tissue with differentiated and functional vessels inside the matrix. Quantitative analysis of vascularization using micro-CT showed to be superior to histological analysis. The micro-CT analysis also allows the assessment of different other, more complex vascularization parameters within 3D constructs, demonstrating an early improvement of vascularization by application of fibrin-gel-immobilized VEGF¹⁶⁵ and bFGF. In this study quantitative analysis of vascularization using micro-CT along with 3D reconstruction and automatic analysis exhibit to be a powerful method superior to histological evaluation of cross sections.

  11. Microstructured barbs on the North American porcupine quill enable easy tissue penetration and difficult removal.

    Science.gov (United States)

    Cho, Woo Kyung; Ankrum, James A; Guo, Dagang; Chester, Shawn A; Yang, Seung Yun; Kashyap, Anurag; Campbell, Georgina A; Wood, Robert J; Rijal, Ram K; Karnik, Rohit; Langer, Robert; Karp, Jeffrey M

    2012-12-26

    North American porcupines are well known for their specialized hairs, or quills that feature microscopic backward-facing deployable barbs that are used in self-defense. Herein we show that the natural quill's geometry enables easy penetration and high tissue adhesion where the barbs specifically contribute to adhesion and unexpectedly, dramatically reduce the force required to penetrate tissue. Reduced penetration force is achieved by topography that appears to create stress concentrations along regions of the quill where the cross sectional diameter grows rapidly, facilitating cutting of the tissue. Barbs located near the first geometrical transition zone exhibit the most substantial impact on minimizing the force required for penetration. Barbs at the tip of the quill independently exhibit the greatest impact on tissue adhesion force and the cooperation between barbs in the 0-2 mm and 2-4 mm regions appears critical to enhance tissue adhesion force. The dual functions of barbs were reproduced with replica molded synthetic polyurethane quills. These findings should serve as the basis for the development of bio-inspired devices such as tissue adhesives or needles, trocars, and vascular tunnelers where minimizing the penetration force is important to prevent collateral damage.

  12. Facial soft-tissue asymmetry in three-dimensional cone-beam computed tomography images of children with surgically corrected unilateral clefts.

    Science.gov (United States)

    Starbuck, John Marlow; Ghoneima, Ahmed; Kula, Katherine

    2014-03-01

    Cleft lip with or without cleft palate (CL/P) is a relatively common craniofacial malformation involving bony and soft-tissue disruptions of the nasolabial and dentoalveolar regions. The combination of CL/P and subsequent craniofacial surgeries to close the cleft and improve appearance of the cutaneous upper lip and nose can cause scarring and muscle pull, possibly resulting in soft-tissue depth asymmetries across the face. We tested the hypothesis that tissue depths in children with unilateral CL/P exhibit differences in symmetry across the sides of the face. Twenty-eight tissue depths were measured on cone-beam computed tomography images of children with unilateral CL/P (n = 55), aged 7 to 17 years, using Dolphin software (version 11.5). Significant differences in tissue depth symmetry were found around the cutaneous upper lip and nose in patients with unilateral CL/P.

  13. TU-F-CAMPUS-T-05: Replacement Computational Phantoms to Estimate Dose in Out-Of-Field Organs and Tissues

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, K [Oregon State University, Corvallis, Oregon (United States); Oregon Health and Science University, Portland, Oregon (United States); Tannous, J; Nabha, R; Feghali, J; Ayoub, Z; Jalbout, W; Youssef, B [American University of Beirut Medical Center, Beirut (Lebanon); Taddei, P [American University of Beirut Medical Center, Beirut (Lebanon); The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: To estimate the absorbed dose in organs and tissues at risk for radiogenic cancer for children receiving photon radiotherapy for localized brain tumors (LBTs) by supplementing their missing body anatomies with those of replacement computational phantoms. Applied beyond the extent of the RT Images collected by computed tomography simulation, these phantoms included RT Image and RT Structure Set objects that encompassed sufficient extents and contours for dosimetric calculations. Method: Nine children, aged 2 to 14 years, who received three-dimensional conformal radiotherapy for low-grade LBTs, were randomly selected for this study under Institutional-Review-Board protocol. Because the extents of their RT Images were cranial only, they were matched for size and sex with patients from a previous study with larger extents and for whom contours of organs at risk for radiogenic cancer had already been delineated. Rigid fusion was performed between the patients’ data and those of the replacement computational phantoms using commercial software. In-field dose was calculated with a clinically-commissioned treatment planning system, and out-of-field dose was estimated with an analytical model. Results: Averaged over all nine children and normalized for a therapeutic dose of 54 Gy prescribed to the PTV, where the PTV is the GTV, the highest mean organ doses were 3.27, 2.41, 1.07, 1.02, 0.24, and 0.24 Gy in the non-tumor remainder, red bone marrow, thyroid, skin, breasts, and lungs, respectively. The mean organ doses ranged by a factor of 3 between the smallest and largest children. Conclusion: For children receiving photon radiotherapy for LBTs, we found their doses in organs at risk for second cancer to be non-negligible, especially in the non-tumor remainder, red bone marrow, thyroid, skin, breasts, and lungs. This study demonstrated the feasibility for patient dosimetry studies to augment missing patient anatomy by applying size- and sex-matched replacement

  14. Large-scale automated image analysis for computational profiling of brain tissue surrounding implanted neuroprosthetic devices using Python.

    Science.gov (United States)

    Rey-Villamizar, Nicolas; Somasundar, Vinay; Megjhani, Murad; Xu, Yan; Lu, Yanbin; Padmanabhan, Raghav; Trett, Kristen; Shain, William; Roysam, Badri

    2014-01-01

    In this article, we describe the use of Python for large-scale automated server-based bio-image analysis in FARSIGHT, a free and open-source toolkit of image analysis methods for quantitative studies of complex and dynamic tissue microenvironments imaged by modern optical microscopes, including confocal, multi-spectral, multi-photon, and time-lapse systems. The core FARSIGHT modules for image segmentation, feature extraction, tracking, and machine learning are written in C++, leveraging widely used libraries including ITK, VTK, Boost, and Qt. For solving complex image analysis tasks, these modules must be combined into scripts using Python. As a concrete example, we consider the problem of analyzing 3-D multi-spectral images of brain tissue surrounding implanted neuroprosthetic devices, acquired using high-throughput multi-spectral spinning disk step-and-repeat confocal microscopy. The resulting images typically contain 5 fluorescent channels. Each channel consists of 6000 × 10,000 × 500 voxels with 16 bits/voxel, implying image sizes exceeding 250 GB. These images must be mosaicked, pre-processed to overcome imaging artifacts, and segmented to enable cellular-scale feature extraction. The features are used to identify cell types, and perform large-scale analysis for identifying spatial distributions of specific cell types relative to the device. Python was used to build a server-based script (Dell 910 PowerEdge servers with 4 sockets/server with 10 cores each, 2 threads per core and 1TB of RAM running on Red Hat Enterprise Linux linked to a RAID 5 SAN) capable of routinely handling image datasets at this scale and performing all these processing steps in a collaborative multi-user multi-platform environment. Our Python script enables efficient data storage and movement between computers and storage servers, logs all the processing steps, and performs full multi-threaded execution of all codes, including open and closed-source third party libraries.

  15. Large-scale automated image analysis for computational profiling of brain tissue surrounding implanted neuroprosthetic devices using Python

    Directory of Open Access Journals (Sweden)

    Nicolas eRey-Villamizar

    2014-04-01

    Full Text Available In this article, we describe use of Python for large-scale automated server-based bio-image analysis in FARSIGHT, a free and open-source toolkit of image analysis methods for quantitative studies of complex and dynamic tissue microenvironments imaged by modern optical microscopes including confocal, multi-spectral, multi-photon, and time-lapse systems. The core FARSIGHT modules for image segmentation, feature extraction, tracking, and machine learning are written in C++, leveraging widely used libraries including ITK, VTK, Boost, and Qt. For solving complex image analysis task, these modules must be combined into scripts using Python. As a concrete example, we consider the problem of analyzing 3-D multi-spectral brain tissue images surrounding implanted neuroprosthetic devices, acquired using high-throughput multi-spectral spinning disk step-and-repeat confocal microscopy. The resulting images typically contain 5 fluorescent channels, 6,000$times$10,000$times$500 voxels with 16 bits/voxel, implying image sizes exceeding 250GB. These images must be mosaicked, pre-processed to overcome imaging artifacts, and segmented to enable cellular-scale feature extraction. The features are used to identify cell types, and perform large-scale analytics for identifying spatial distributions of specific cell types relative to the device. Python was used to build a server-based script (Dell 910 PowerEdge servers with 4 sockets/server with 10 cores each, 2 threads per core and 1TB of RAM running on Red Hat Enterprise Linux linked to a RAID 5 SAN capable of routinely handling image datasets at this scale and performing all these processing steps in a collaborative multi-user multi-platform environment consisting. Our Python script enables efficient data storage and movement between compute and storage servers, logging all processing steps, and performs full multi-threaded execution of all codes, including open and closed-source third party libraries.

  16. Image microarrays derived from tissue microarrays (IMA-TMA: New resource for computer-aided diagnostic algorithm development

    Directory of Open Access Journals (Sweden)

    Jennifer A Hipp

    2012-01-01

    Full Text Available Background: Conventional tissue microarrays (TMAs consist of cores of tissue inserted into a recipient paraffin block such that a tissue section on a single glass slide can contain numerous patient samples in a spatially structured pattern. Scanning TMAs into digital slides for subsequent analysis by computer-aided diagnostic (CAD algorithms all offers the possibility of evaluating candidate algorithms against a near-complete repertoire of variable disease morphologies. This parallel interrogation approach simplifies the evaluation, validation, and comparison of such candidate algorithms. A recently developed digital tool, digital core (dCORE, and image microarray maker (iMAM enables the capture of uniformly sized and resolution-matched images, with these representing key morphologic features and fields of view, aggregated into a single monolithic digital image file in an array format, which we define as an image microarray (IMA. We further define the TMA-IMA construct as IMA-based images derived from whole slide images of TMAs themselves. Methods: Here we describe the first combined use of the previously described dCORE and iMAM tools, toward the goal of generating a higher-order image construct, with multiple TMA cores from multiple distinct conventional TMAs assembled as a single digital image montage. This image construct served as the basis of the carrying out of a massively parallel image analysis exercise, based on the use of the previously described spatially invariant vector quantization (SIVQ algorithm. Results: Multicase, multifield TMA-IMAs of follicular lymphoma and follicular hyperplasia were separately rendered, using the aforementioned tools. Each of these two IMAs contained a distinct spectrum of morphologic heterogeneity with respect to both tingible body macrophage (TBM appearance and apoptotic body morphology. SIVQ-based pattern matching, with ring vectors selected to screen for either tingible body macrophages or apoptotic

  17. Fog computing job scheduling optimization based on bees swarm

    Science.gov (United States)

    Bitam, Salim; Zeadally, Sherali; Mellouk, Abdelhamid

    2018-04-01

    Fog computing is a new computing architecture, composed of a set of near-user edge devices called fog nodes, which collaborate together in order to perform computational services such as running applications, storing an important amount of data, and transmitting messages. Fog computing extends cloud computing by deploying digital resources at the premise of mobile users. In this new paradigm, management and operating functions, such as job scheduling aim at providing high-performance, cost-effective services requested by mobile users and executed by fog nodes. We propose a new bio-inspired optimization approach called Bees Life Algorithm (BLA) aimed at addressing the job scheduling problem in the fog computing environment. Our proposed approach is based on the optimized distribution of a set of tasks among all the fog computing nodes. The objective is to find an optimal tradeoff between CPU execution time and allocated memory required by fog computing services established by mobile users. Our empirical performance evaluation results demonstrate that the proposal outperforms the traditional particle swarm optimization and genetic algorithm in terms of CPU execution time and allocated memory.

  18. Automatic bone detection and soft tissue aware ultrasound-CT registration for computer-aided orthopedic surgery.

    Science.gov (United States)

    Wein, Wolfgang; Karamalis, Athanasios; Baumgartner, Adrian; Navab, Nassir

    2015-06-01

    The transfer of preoperative CT data into the tracking system coordinates within an operating room is of high interest for computer-aided orthopedic surgery. In this work, we introduce a solution for intra-operative ultrasound-CT registration of bones. We have developed methods for fully automatic real-time bone detection in ultrasound images and global automatic registration to CT. The bone detection algorithm uses a novel bone-specific feature descriptor and was thoroughly evaluated on both in-vivo and ex-vivo data. A global optimization strategy aligns the bone surface, followed by a soft tissue aware intensity-based registration to provide higher local registration accuracy. We evaluated the system on femur, tibia and fibula anatomy in a cadaver study with human legs, where magnetically tracked bone markers were implanted to yield ground truth information. An overall median system error of 3.7 mm was achieved on 11 datasets. Global and fully automatic registration of bones aquired with ultrasound to CT is feasible, with bone detection and tracking operating in real time for immediate feedback to the surgeon.

  19. Evaluation of computer-based computer tomography stratification against outcome models in connective tissue disease-related interstitial lung disease: a patient outcome study.

    Science.gov (United States)

    Jacob, Joseph; Bartholmai, Brian J; Rajagopalan, Srinivasan; Brun, Anne Laure; Egashira, Ryoko; Karwoski, Ronald; Kokosi, Maria; Wells, Athol U; Hansell, David M

    2016-11-23

    To evaluate computer-based computer tomography (CT) analysis (CALIPER) against visual CT scoring and pulmonary function tests (PFTs) when predicting mortality in patients with connective tissue disease-related interstitial lung disease (CTD-ILD). To identify outcome differences between distinct CTD-ILD groups derived following automated stratification of CALIPER variables. A total of 203 consecutive patients with assorted CTD-ILDs had CT parenchymal patterns evaluated by CALIPER and visual CT scoring: honeycombing, reticular pattern, ground glass opacities, pulmonary vessel volume, emphysema, and traction bronchiectasis. CT scores were evaluated against pulmonary function tests: forced vital capacity, diffusing capacity for carbon monoxide, carbon monoxide transfer coefficient, and composite physiologic index for mortality analysis. Automated stratification of CALIPER-CT variables was evaluated in place of and alongside forced vital capacity and diffusing capacity for carbon monoxide in the ILD gender, age physiology (ILD-GAP) model using receiver operating characteristic curve analysis. Cox regression analyses identified four independent predictors of mortality: patient age (P < 0.0001), smoking history (P = 0.0003), carbon monoxide transfer coefficient (P = 0.003), and pulmonary vessel volume (P < 0.0001). Automated stratification of CALIPER variables identified three morphologically distinct groups which were stronger predictors of mortality than all CT and functional indices. The Stratified-CT model substituted automated stratified groups for functional indices in the ILD-GAP model and maintained model strength (area under curve (AUC) = 0.74, P < 0.0001), ILD-GAP (AUC = 0.72, P < 0.0001). Combining automated stratified groups with the ILD-GAP model (stratified CT-GAP model) strengthened predictions of 1- and 2-year mortality: ILD-GAP (AUC = 0.87 and 0.86, respectively); stratified CT-GAP (AUC = 0.89 and 0.88, respectively

  20. Digital dissection - using contrast-enhanced computed tomography scanning to elucidate hard- and soft-tissue anatomy in the Common Buzzard Buteo buteo.

    Science.gov (United States)

    Lautenschlager, Stephan; Bright, Jen A; Rayfield, Emily J

    2014-04-01

    Gross dissection has a long history as a tool for the study of human or animal soft- and hard-tissue anatomy. However, apart from being a time-consuming and invasive method, dissection is often unsuitable for very small specimens and often cannot capture spatial relationships of the individual soft-tissue structures. The handful of comprehensive studies on avian anatomy using traditional dissection techniques focus nearly exclusively on domestic birds, whereas raptorial birds, and in particular their cranial soft tissues, are essentially absent from the literature. Here, we digitally dissect, identify, and document the soft-tissue anatomy of the Common Buzzard (Buteo buteo) in detail, using the new approach of contrast-enhanced computed tomography using Lugol's iodine. The architecture of different muscle systems (adductor, depressor, ocular, hyoid, neck musculature), neurovascular, and other soft-tissue structures is three-dimensionally visualised and described in unprecedented detail. The three-dimensional model is further presented as an interactive PDF to facilitate the dissemination and accessibility of anatomical data. Due to the digital nature of the data derived from the computed tomography scanning and segmentation processes, these methods hold the potential for further computational analyses beyond descriptive and illustrative proposes. © 2013 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

  1. Tissue Classification

    DEFF Research Database (Denmark)

    Van Leemput, Koen; Puonti, Oula

    2015-01-01

    Computational methods for automatically segmenting magnetic resonance images of the brain have seen tremendous advances in recent years. So-called tissue classification techniques, aimed at extracting the three main brain tissue classes (white matter, gray matter, and cerebrospinal fluid), are now...... well established. In their simplest form, these methods classify voxels independently based on their intensity alone, although much more sophisticated models are typically used in practice. This article aims to give an overview of often-used computational techniques for brain tissue classification...

  2. Biased visualization of hypoperfused tissue by computed tomography due to short imaging duration: improved classification by image down-sampling and vascular models

    Energy Technology Data Exchange (ETDEWEB)

    Mikkelsen, Irene Klaerke; Ribe, Lars Riisgaard; Bekke, Susanne Lise; Tietze, Anna; Oestergaard, Leif; Mouridsen, Kim [Aarhus University Hospital, Center of Functionally Integrative Neuroscience, Aarhus C (Denmark); Jones, P.S.; Alawneh, Josef [University of Cambridge, Department of Clinical Neurosciences, Cambridge (United Kingdom); Puig, Josep; Pedraza, Salva [Dr. Josep Trueta Girona University Hospitals, Department of Radiology, Girona Biomedical Research Institute, Girona (Spain); Gillard, Jonathan H. [University of Cambridge, Department of Radiology, Cambridge (United Kingdom); Warburton, Elisabeth A. [Cambrigde University Hospitals, Addenbrooke, Stroke Unit, Cambridge (United Kingdom); Baron, Jean-Claude [University of Cambridge, Department of Clinical Neurosciences, Cambridge (United Kingdom); Centre Hospitalier Sainte Anne, INSERM U894, Paris (France)

    2015-07-15

    Lesion detection in acute stroke by computed-tomography perfusion (CTP) can be affected by incomplete bolus coverage in veins and hypoperfused tissue, so-called bolus truncation (BT), and low contrast-to-noise ratio (CNR). We examined the BT-frequency and hypothesized that image down-sampling and a vascular model (VM) for perfusion calculation would improve normo- and hypoperfused tissue classification. CTP datasets from 40 acute stroke patients were retrospectively analysed for BT. In 16 patients with hypoperfused tissue but no BT, repeated 2-by-2 image down-sampling and uniform filtering was performed, comparing CNR to perfusion-MRI levels and tissue classification to that of unprocessed data. By simulating reduced scan duration, the minimum scan-duration at which estimated lesion volumes came within 10 % of their true volume was compared for VM and state-of-the-art algorithms. BT in veins and hypoperfused tissue was observed in 9/40 (22.5 %) and 17/40 patients (42.5 %), respectively. Down-sampling to 128 x 128 resolution yielded CNR comparable to MR data and improved tissue classification (p = 0.0069). VM reduced minimum scan duration, providing reliable maps of cerebral blood flow and mean transit time: 5 s (p = 0.03) and 7 s (p < 0.0001), respectively. BT is not uncommon in stroke CTP with 40-s scan duration. Applying image down-sampling and VM improve tissue classification. (orig.)

  3. Biased visualization of hypoperfused tissue by computed tomography due to short imaging duration: improved classification by image down-sampling and vascular models

    International Nuclear Information System (INIS)

    Mikkelsen, Irene Klaerke; Ribe, Lars Riisgaard; Bekke, Susanne Lise; Tietze, Anna; Oestergaard, Leif; Mouridsen, Kim; Jones, P.S.; Alawneh, Josef; Puig, Josep; Pedraza, Salva; Gillard, Jonathan H.; Warburton, Elisabeth A.; Baron, Jean-Claude

    2015-01-01

    Lesion detection in acute stroke by computed-tomography perfusion (CTP) can be affected by incomplete bolus coverage in veins and hypoperfused tissue, so-called bolus truncation (BT), and low contrast-to-noise ratio (CNR). We examined the BT-frequency and hypothesized that image down-sampling and a vascular model (VM) for perfusion calculation would improve normo- and hypoperfused tissue classification. CTP datasets from 40 acute stroke patients were retrospectively analysed for BT. In 16 patients with hypoperfused tissue but no BT, repeated 2-by-2 image down-sampling and uniform filtering was performed, comparing CNR to perfusion-MRI levels and tissue classification to that of unprocessed data. By simulating reduced scan duration, the minimum scan-duration at which estimated lesion volumes came within 10 % of their true volume was compared for VM and state-of-the-art algorithms. BT in veins and hypoperfused tissue was observed in 9/40 (22.5 %) and 17/40 patients (42.5 %), respectively. Down-sampling to 128 x 128 resolution yielded CNR comparable to MR data and improved tissue classification (p = 0.0069). VM reduced minimum scan duration, providing reliable maps of cerebral blood flow and mean transit time: 5 s (p = 0.03) and 7 s (p < 0.0001), respectively. BT is not uncommon in stroke CTP with 40-s scan duration. Applying image down-sampling and VM improve tissue classification. (orig.)

  4. Theoretical variance analysis of single- and dual-energy computed tomography methods for calculating proton stopping power ratios of biological tissues

    International Nuclear Information System (INIS)

    Yang, M; Zhu, X R; Mohan, R; Dong, L; Virshup, G; Clayton, J

    2010-01-01

    We discovered an empirical relationship between the logarithm of mean excitation energy (ln I m ) and the effective atomic number (EAN) of human tissues, which allows for computing patient-specific proton stopping power ratios (SPRs) using dual-energy CT (DECT) imaging. The accuracy of the DECT method was evaluated for 'standard' human tissues as well as their variance. The DECT method was compared to the existing standard clinical practice-a procedure introduced by Schneider et al at the Paul Scherrer Institute (the stoichiometric calibration method). In this simulation study, SPRs were derived from calculated CT numbers of known material compositions, rather than from measurement. For standard human tissues, both methods achieved good accuracy with the root-mean-square (RMS) error well below 1%. For human tissues with small perturbations from standard human tissue compositions, the DECT method was shown to be less sensitive than the stoichiometric calibration method. The RMS error remained below 1% for most cases using the DECT method, which implies that the DECT method might be more suitable for measuring patient-specific tissue compositions to improve the accuracy of treatment planning for charged particle therapy. In this study, the effects of CT imaging artifacts due to the beam hardening effect, scatter, noise, patient movement, etc were not analyzed. The true potential of the DECT method achieved in theoretical conditions may not be fully achievable in clinical settings. Further research and development may be needed to take advantage of the DECT method to characterize individual human tissues.

  5. The value of computed tomography in the diagnosis of the rotator cuff tears, and bone and soft tissue tumors

    International Nuclear Information System (INIS)

    Yoh, Sansen

    1984-01-01

    The usefulness of computed tomography (CT) in the diagnosis of rotator cuff tear was assessed. The rotator cuff could not be visualized in detail by CT unless introduction of contrast material into the joint cavity was performed. CT arthrography was performed on 21 cases of rotator cuff tears. The most detailed information was obtained when a relatively low concentration of contrast material (3.25% Angiografin) was filled in the joint cavity, and when the shoulder joint was rotated to the maximum outwards at the side. CT arthrography proved to be the most reliable method for assessing the extent and portion of the rotator cuff tears, so that it demonstrated conclusive evidence of diagnosis and management in 89% of patients studied. The usefulness of CT in the diagnosis of bone and soft tissue tumors was assessed. CT examination provided unique preoperative information which could imagine a more precise histological characteristics and anatomical localization of the lesion. Contrast enhancement (CE), when used, proved to be helpful in predicting the nature of tumors. The CE by intra-arterial infusion, or intravenous bolous injection of contrast material during the scan was more useful than that by intervenous drip infusion of the material. The information regarding change of tumor size, CT number and CE were appropriate indicators which directly corresponded to responsiveness of the tumor to the chemotheraphy and radiotherapy performed. Preoperative ABC classification of the tumor by information regarding its size, location, definition and anatomical relation of tumors to vital structures (neural, vescular, and visceral) was done by using CT. The classification clearly corresponded to the status of patients regarding the treatment required for the patients. (author)

  6. Soft-tissue perineurioma of the retroperitoneum in a 63-year-old man, computed tomography and magnetic resonance imaging findings: a case report

    Directory of Open Access Journals (Sweden)

    Yasumoto Mayumi

    2010-08-01

    Full Text Available Abstract Introduction Soft-tissue perineuriomas are rare benign peripheral nerve sheath tumors in the subcutis of the extremities and the trunks of young patients. To our knowledge, this the first presentation of the computed tomography and magnetic resonance imaging of a soft-tissue perineurioma in the retroperitoneum with pathologic correlation. Case presentation A 63-year-old Japanese man was referred for assessment of high blood pressure. Abdominal computed tomography and magnetic resonance imaging showed a well-defined, gradually enhancing tumor without focal degeneration or hemorrhage adjacent to the pancreatic body. Tumor excision with distal pancreatectomy and splenectomy was performed, as a malignant tumor of pancreatic origin could not be ruled out. No recurrence has been noted in the 16 months since the operation. Pathologic examination of the tumor revealed a soft-tissue perineurioma of the retroperitoneum. Conclusion Although the definitive diagnosis of soft-tissue perineurioma requires biopsy and immunohistochemical reactivity evaluation, the computed tomography and magnetic resonance imaging findings described in this report suggest inclusion of this rare tumor in the differential diagnosis when such findings occur in the retroperitoneum.

  7. A Tissue Relevance and Meshing Method for Computing Patient-Specific Anatomical Models in Endoscopic Sinus Surgery Simulation

    Science.gov (United States)

    Audette, M. A.; Hertel, I.; Burgert, O.; Strauss, G.

    This paper presents on-going work on a method for determining which subvolumes of a patient-specific tissue map, extracted from CT data of the head, are relevant to simulating endoscopic sinus surgery of that individual, and for decomposing these relevant tissues into triangles and tetrahedra whose mesh size is well controlled. The overall goal is to limit the complexity of the real-time biomechanical interaction while ensuring the clinical relevance of the simulation. Relevant tissues are determined as the union of the pathology present in the patient, of critical tissues deemed to be near the intended surgical path or pathology, and of bone and soft tissue near the intended path, pathology or critical tissues. The processing of tissues, prior to meshing, is based on the Fast Marching method applied under various guises, in a conditional manner that is related to tissue classes. The meshing is based on an adaptation of a meshing method of ours, which combines the Marching Tetrahedra method and the discrete Simplex mesh surface model to produce a topologically faithful surface mesh with well controlled edge and face size as a first stage, and Almost-regular Tetrahedralization of the same prescribed mesh size as a last stage.

  8. Gender disparities in the association between epicardial adipose tissue volume and coronary atherosclerosis: A 3-dimensional cardiac computed tomography imaging study in Japanese subjects

    OpenAIRE

    Dagvasumberel Munkhbaatar; Shimabukuro Michio; Nishiuchi Takeshi; Ueno Junji; Takao Shoichiro; Fukuda Daiju; Hirata Yoichiro; Kurobe Hirotsugu; Soeki Takeshi; Iwase Takashi; Kusunose Kenya; Niki Toshiyuki; Yamaguchi Koji; Taketani Yoshio; Yagi Shusuke

    2012-01-01

    Abstract Background Growing evidence suggests that epicardial adipose tissue (EAT) may contribute to the development of coronary artery disease (CAD). In this study, we explored gender disparities in EAT volume (EATV) and its impact on coronary atherosclerosis. Methods The study population consisted of 90 consecutive subjects (age: 63 ± 12 years; men: 47, women: 43) who underwent 256-slice multi-detector computed tomography (MDCT) coronary angiography. EATV was measured as the sum of cross-se...

  9. Experimental verification of stopping-power prediction from single- and dual-energy computed tomography in biological tissues

    Science.gov (United States)

    Möhler, Christian; Russ, Tom; Wohlfahrt, Patrick; Elter, Alina; Runz, Armin; Richter, Christian; Greilich, Steffen

    2018-01-01

    An experimental setup for consecutive measurement of ion and x-ray absorption in tissue or other materials is introduced. With this setup using a 3D-printed sample container, the reference stopping-power ratio (SPR) of materials can be measured with an uncertainty of below 0.1%. A total of 65 porcine and bovine tissue samples were prepared for measurement, comprising five samples each of 13 tissue types representing about 80% of the total body mass (three different muscle and fatty tissues, liver, kidney, brain, heart, blood, lung and bone). Using a standard stoichiometric calibration for single-energy CT (SECT) as well as a state-of-the-art dual-energy CT (DECT) approach, SPR was predicted for all tissues and then compared to the measured reference. With the SECT approach, the SPRs of all tissues were predicted with a mean error of (-0.84  ±  0.12)% and a mean absolute error of (1.27  ±  0.12)%. In contrast, the DECT-based SPR predictions were overall consistent with the measured reference with a mean error of (-0.02  ±  0.15)% and a mean absolute error of (0.10  ±  0.15)%. Thus, in this study, the potential of DECT to decrease range uncertainty could be confirmed in biological tissue.

  10. Learning from evolutionary optimisation: what are toughening mechanisms good for in dentine, a nonrepairing bone tissue?

    Science.gov (United States)

    Zaslansky, Paul; Currey, John D; Fleck, Claudia

    2016-09-12

    The main mass of material found in teeth is dentine, a bone-like tissue, riddled with micron-sized tubules and devoid of living cells. It provides support to the outer wear-resistant layer of enamel, and exhibits toughening mechanisms which contribute to crack resistance. And yet unlike most bone tissues, dentine does not remodel and consequently any accumulated damage does not 'self repair'. Because damage containment followed by tissue replacement is a prime reason for the crack-arresting microstructures found in most bones, the occurrence of toughening mechanisms without the biological capability to repair is puzzling. Here we consider the notion that dentine might be overdesigned for strength, because it has to compensate for the lack of cell-mediated healing mechanisms. Based on our own and on literature-reported observations, including quasistatic and fatigue properties, dentine design principles are discussed in light of the functional conditions under which teeth evolved. We conclude that dentine is only slightly overdesigned for everyday cyclic loading because usual mastication stresses may come close to its endurance strength. The in-built toughening mechanisms constitute an evolutionary benefit because they prevent catastrophic failure during rare overload events, which was probably very advantageous in our hunter gatherer ancestor times. From a bio-inspired perspective, understanding the extent of evolutionary overdesign might be useful for optimising biomimetic structures used for load bearing.

  11. Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

    Directory of Open Access Journals (Sweden)

    Muhammed Bora Demircelik

    2014-06-01

    Full Text Available OBJECTIVE:The aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease.METHODS:The study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing <50% in diameter, Group 2; and obstructive atherosclerosis (luminal narrowing ≥50% in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium. Epicardial adipose tissue thickness (mm was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses.RESULTS:The average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm.CONCLUSION:We showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases.

  12. Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Demircelik, Muhammed Bora; Gurel, Ozgul Malcok; Selcoki, Yusuf; Atar, Inci Asli; Eryonucu, Beyhan, E-mail: drdemircelik@yahoo.com [Turgut Ozal Univercity, Department of Cardiology, Ankara (Turkey); Bozkurt, Alper; Akin, Kayihan [Turgut Ozal Univercity, Department of Radiology, Ankara (Turkey); Yilmaz, Omer Caglar [Ankara Occupational Diseases Hospital, Department of Cardiology, Ankara (Turkey)

    2014-06-15

    Objective: the aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease. Methods: the study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing < 50% in diameter), Group 2; and obstructive atherosclerosis (luminal narrowing ≧ 50%) in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium). Epicardial adipose tissue thickness (mm) was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses. Results: the average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm. Conclusion: we showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases. (author)

  13. Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

    International Nuclear Information System (INIS)

    Demircelik, Muhammed Bora; Gurel, Ozgul Malcok; Selcoki, Yusuf; Atar, Inci Asli; Eryonucu, Beyhan; Bozkurt, Alper; Akin, Kayihan; Yilmaz, Omer Caglar

    2014-01-01

    Objective: the aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease. Methods: the study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing < 50% in diameter), Group 2; and obstructive atherosclerosis (luminal narrowing ≧ 50%) in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium). Epicardial adipose tissue thickness (mm) was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses. Results: the average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm. Conclusion: we showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases. (author)

  14. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview In autumn the main focus was to process and handle CRAFT data and to perform the Summer08 MC production. The operational aspects were well covered by regular Computing Shifts, experts on duty and Computing Run Coordination. At the Computing Resource Board (CRB) in October a model to account for service work at Tier 2s was approved. The computing resources for 2009 were reviewed for presentation at the C-RRB. The quarterly resource monitoring is continuing. Facilities/Infrastructure operations Operations during CRAFT data taking ran fine. This proved to be a very valuable experience for T0 workflows and operations. The transfers of custodial data to most T1s went smoothly. A first round of reprocessing started at the Tier-1 centers end of November; it will take about two weeks. The Computing Shifts procedure was tested full scale during this period and proved to be very efficient: 30 Computing Shifts Persons (CSP) and 10 Computing Resources Coordinators (CRC). The shift program for the shut down w...

  15. Application of an object-oriented programming paradigm in three-dimensional computer modeling of mechanically active gastrointestinal tissues.

    Science.gov (United States)

    Rashev, P Z; Mintchev, M P; Bowes, K L

    2000-09-01

    The aim of this study was to develop a novel three-dimensional (3-D) object-oriented modeling approach incorporating knowledge of the anatomy, electrophysiology, and mechanics of externally stimulated excitable gastrointestinal (GI) tissues and emphasizing the "stimulus-response" principle of extracting the modeling parameters. The modeling method used clusters of class hierarchies representing GI tissues from three perspectives: 1) anatomical; 2) electrophysiological; and 3) mechanical. We elaborated on the first four phases of the object-oriented system development life-cycle: 1) analysis; 2) design; 3) implementation; and 4) testing. Generalized cylinders were used for the implementation of 3-D tissue objects modeling the cecum, the descending colon, and the colonic circular smooth muscle tissue. The model was tested using external neural electrical tissue excitation of the descending colon with virtual implanted electrodes and the stimulating current density distributions over the modeled surfaces were calculated. Finally, the tissue deformations invoked by electrical stimulation were estimated and represented by a mesh-surface visualization technique.

  16. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction CMS distributed computing system performed well during the 2011 start-up. The events in 2011 have more pile-up and are more complex than last year; this results in longer reconstruction times and harder events to simulate. Significant increases in computing capacity were delivered in April for all computing tiers, and the utilisation and load is close to the planning predictions. All computing centre tiers performed their expected functionalities. Heavy-Ion Programme The CMS Heavy-Ion Programme had a very strong showing at the Quark Matter conference. A large number of analyses were shown. The dedicated heavy-ion reconstruction facility at the Vanderbilt Tier-2 is still involved in some commissioning activities, but is available for processing and analysis. Facilities and Infrastructure Operations Facility and Infrastructure operations have been active with operations and several important deployment tasks. Facilities participated in the testing and deployment of WMAgent and WorkQueue+Request...

  17. COMPUTING

    CERN Multimedia

    P. McBride

    The Computing Project is preparing for a busy year where the primary emphasis of the project moves towards steady operations. Following the very successful completion of Computing Software and Analysis challenge, CSA06, last fall, we have reorganized and established four groups in computing area: Commissioning, User Support, Facility/Infrastructure Operations and Data Operations. These groups work closely together with groups from the Offline Project in planning for data processing and operations. Monte Carlo production has continued since CSA06, with about 30M events produced each month to be used for HLT studies and physics validation. Monte Carlo production will continue throughout the year in the preparation of large samples for physics and detector studies ramping to 50 M events/month for CSA07. Commissioning of the full CMS computing system is a major goal for 2007. Site monitoring is an important commissioning component and work is ongoing to devise CMS specific tests to be included in Service Availa...

  18. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview During the past three months activities were focused on data operations, testing and re-enforcing shift and operational procedures for data production and transfer, MC production and on user support. Planning of the computing resources in view of the new LHC calendar in ongoing. Two new task forces were created for supporting the integration work: Site Commissioning, which develops tools helping distributed sites to monitor job and data workflows, and Analysis Support, collecting the user experience and feedback during analysis activities and developing tools to increase efficiency. The development plan for DMWM for 2009/2011 was developed at the beginning of the year, based on the requirements from the Physics, Computing and Offline groups (see Offline section). The Computing management meeting at FermiLab on February 19th and 20th was an excellent opportunity discussing the impact and for addressing issues and solutions to the main challenges facing CMS computing. The lack of manpower is particul...

  19. Analyses of the eustachian tube and its surrounding tissues with cross sectional images by high-resolution computed tomography (HR-CT)

    International Nuclear Information System (INIS)

    Yoshida, Haruo; Kobayashi, Toshimitsu; Takasaki, Kenji; Kanda, Yukihiko; Nakao, Yoshiaki; Morikawa, Minoru; Ishimaru, Hideki; Hayashi, Kuniaki

    2000-01-01

    We attempted to image the eustachian tube (ET) and its surrounding tissues by high-resolution computed tomography (HR-CT). Twenty-two normal subjects (44 ears) without middle ear problems were studied, and a patient with severe patulous ET was also studied as an abnormal case. In our device of multiplanar reconstruction technique, we were able to obtain the clear reconstructed images of the ET lumen as well as of its surrounding tissues (bone, ET cartilage, tensor veli palatini muscle, levator veli palatini muscle, Ostmann's fat tissue, tensor tympani muscle, internal carotid artery) at any desired portion, either parallel or perpendicular to the long axis of the ET. However, the exact borders between the ET cartilage and the muscles, Ostmann's fat tissue and the tubal gland were not clearly identified. In the severe case of patulous ET, the ET lumen was widely opened at each cross-sectional image from the pharyngeal orifice to the tympanic orifice, in contrast with its being closed at the cartilaginous portion in the normal cases. In addition, the fat tissue and glands around the ET lumen were not clearly identified in this case. We suggest that this method will lead to better understanding of the ET-related diseases such as patulous ET. (author)

  20. Analyses of the eustachian tube and its surrounding tissues with cross sectional images by high-resolution computed tomography (HR-CT)

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Haruo; Kobayashi, Toshimitsu; Takasaki, Kenji; Kanda, Yukihiko; Nakao, Yoshiaki; Morikawa, Minoru; Ishimaru, Hideki; Hayashi, Kuniaki [Nagasaki Univ. (Japan). School of Medicine

    2000-07-01

    We attempted to image the eustachian tube (ET) and its surrounding tissues by high-resolution computed tomography (HR-CT). Twenty-two normal subjects (44 ears) without middle ear problems were studied, and a patient with severe patulous ET was also studied as an abnormal case. In our device of multiplanar reconstruction technique, we were able to obtain the clear reconstructed images of the ET lumen as well as of its surrounding tissues (bone, ET cartilage, tensor veli palatini muscle, levator veli palatini muscle, Ostmann's fat tissue, tensor tympani muscle, internal carotid artery) at any desired portion, either parallel or perpendicular to the long axis of the ET. However, the exact borders between the ET cartilage and the muscles, Ostmann's fat tissue and the tubal gland were not clearly identified. In the severe case of patulous ET, the ET lumen was widely opened at each cross-sectional image from the pharyngeal orifice to the tympanic orifice, in contrast with its being closed at the cartilaginous portion in the normal cases. In addition, the fat tissue and glands around the ET lumen were not clearly identified in this case. We suggest that this method will lead to better understanding of the ET-related diseases such as patulous ET. (author)

  1. Constructing optimized binary masks for reservoir computing with delay systems

    Science.gov (United States)

    Appeltant, Lennert; van der Sande, Guy; Danckaert, Jan; Fischer, Ingo

    2014-01-01

    Reservoir computing is a novel bio-inspired computing method, capable of solving complex tasks in a computationally efficient way. It has recently been successfully implemented using delayed feedback systems, allowing to reduce the hardware complexity of brain-inspired computers drastically. In this approach, the pre-processing procedure relies on the definition of a temporal mask which serves as a scaled time-mutiplexing of the input. Originally, random masks had been chosen, motivated by the random connectivity in reservoirs. This random generation can sometimes fail. Moreover, for hardware implementations random generation is not ideal due to its complexity and the requirement for trial and error. We outline a procedure to reliably construct an optimal mask pattern in terms of multipurpose performance, derived from the concept of maximum length sequences. Not only does this ensure the creation of the shortest possible mask that leads to maximum variability in the reservoir states for the given reservoir, it also allows for an interpretation of the statistical significance of the provided training samples for the task at hand.

  2. Human in vitro 3D co-culture model to engineer vascularized bone-mimicking tissues combining computational tools and statistical experimental approach.

    Science.gov (United States)

    Bersini, Simone; Gilardi, Mara; Arrigoni, Chiara; Talò, Giuseppe; Zamai, Moreno; Zagra, Luigi; Caiolfa, Valeria; Moretti, Matteo

    2016-01-01

    The generation of functional, vascularized tissues is a key challenge for both tissue engineering applications and the development of advanced in vitro models analyzing interactions among circulating cells, endothelium and organ-specific microenvironments. Since vascularization is a complex process guided by multiple synergic factors, it is critical to analyze the specific role that different experimental parameters play in the generation of physiological tissues. Our goals were to design a novel meso-scale model bridging the gap between microfluidic and macro-scale studies, and high-throughput screen the effects of multiple variables on the vascularization of bone-mimicking tissues. We investigated the influence of endothelial cell (EC) density (3-5 Mcells/ml), cell ratio among ECs, mesenchymal stem cells (MSCs) and osteo-differentiated MSCs (1:1:0, 10:1:0, 10:1:1), culture medium (endothelial, endothelial + angiopoietin-1, 1:1 endothelial/osteo), hydrogel type (100%fibrin, 60%fibrin+40%collagen), tissue geometry (2 × 2 × 2, 2 × 2 × 5 mm(3)). We optimized the geometry and oxygen gradient inside hydrogels through computational simulations and we analyzed microvascular network features including total network length/area and vascular branch number/length. Particularly, we employed the "Design of Experiment" statistical approach to identify key differences among experimental conditions. We combined the generation of 3D functional tissue units with the fine control over the local microenvironment (e.g. oxygen gradients), and developed an effective strategy to enable the high-throughput screening of multiple experimental parameters. Our approach allowed to identify synergic correlations among critical parameters driving microvascular network development within a bone-mimicking environment and could be translated to any vascularized tissue. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Dependence of light scattering profile in tissue on blood vessel diameter and distribution: a computer simulation study.

    Science.gov (United States)

    Duadi, Hamootal; Fixler, Dror; Popovtzer, Rachela

    2013-11-01

    Most methods for measuring light-tissue interactions focus on the volume reflectance while very few measure the transmission. We investigate both diffusion reflection and diffuse transmission at all exit angles to receive the full scattering profile. We also investigate the influence of blood vessel diameter on the scattering profile of a circular tissue. The photon propagation path at a wavelength of 850 nm is calculated from the absorption and scattering constants via Monte Carlo simulation. Several simulations are performed where a different vessel diameter and location were chosen but the blood volume was kept constant. The fraction of photons exiting the tissue at several central angles is presented for each vessel diameter. The main result is that there is a central angle that below which the photon transmission decreased for lower vessel diameters while above this angle the opposite occurred. We find this central angle to be 135 deg for a two-dimensional 10-mm diameter circular tissue cross-section containing blood vessels. These findings can be useful for monitoring blood perfusion and oxygen delivery in the ear lobe and pinched tissues. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)

  4. COMPUTING

    CERN Multimedia

    I. Fisk

    2013-01-01

    Computing activity had ramped down after the completion of the reprocessing of the 2012 data and parked data, but is increasing with new simulation samples for analysis and upgrade studies. Much of the Computing effort is currently involved in activities to improve the computing system in preparation for 2015. Operations Office Since the beginning of 2013, the Computing Operations team successfully re-processed the 2012 data in record time, not only by using opportunistic resources like the San Diego Supercomputer Center which was accessible, to re-process the primary datasets HTMHT and MultiJet in Run2012D much earlier than planned. The Heavy-Ion data-taking period was successfully concluded in February collecting almost 500 T. Figure 3: Number of events per month (data) In LS1, our emphasis is to increase efficiency and flexibility of the infrastructure and operation. Computing Operations is working on separating disk and tape at the Tier-1 sites and the full implementation of the xrootd federation ...

  5. COMPUTING

    CERN Multimedia

    I. Fisk

    2010-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion An activity that is still in progress is computing for the heavy-ion program. The heavy-ion events are collected without zero suppression, so the event size is much large at roughly 11 MB per event of RAW. The central collisions are more complex and...

  6. COMPUTING

    CERN Multimedia

    M. Kasemann P. McBride Edited by M-C. Sawley with contributions from: P. Kreuzer D. Bonacorsi S. Belforte F. Wuerthwein L. Bauerdick K. Lassila-Perini M-C. Sawley

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the comput...

  7. Ribose mediated crosslinking of collagen-hydroxyapatite hybrid scaffolds for bone tissue regeneration using biomimetic strategies.

    Science.gov (United States)

    Krishnakumar, Gopal Shankar; Gostynska, Natalia; Campodoni, Elisabetta; Dapporto, Massimiliano; Montesi, Monica; Panseri, Silvia; Tampieri, Anna; Kon, Elizaveta; Marcacci, Maurilio; Sprio, Simone; Sandri, Monica

    2017-08-01

    This study explores for the first time the application of ribose as a highly biocompatible agent for the crosslinking of hybrid mineralized constructs, obtained by bio-inspired mineralization of self-assembling Type I collagen matrix with magnesium-doped-hydroxyapatite nanophase, towards a biomimetic mineralized 3D scaffolds (MgHA/Coll) with excellent compositional and structural mimicry of bone tissue. To this aim, two different crosslinking mechanisms in terms of pre-ribose glycation (before freeze drying) and post-ribose glycation (after freeze drying) were investigated. The obtained results explicate that with controlled freeze-drying, highly anisotropic porous structures with opportune macro-micro porosity are obtained. The physical-chemical features of the scaffolds characterized by XRD, FTIR, ICP and TGA demonstrated structural mimicry analogous to the native bone. The influence of ribose greatly assisted in decreasing solubility and increased enzymatic resistivity of the scaffolds. In addition, enhanced mechanical behaviour in response to compressive forces was achieved. Preliminary cell culture experiments reported good cytocompatibility with extensive cell adhesion, proliferation and colonization. Overall, scaffolds developed by pre-ribose glycation process are preferred, as the related crosslinking technique is more facile and robust to obtain functional scaffolds. As a proof of concept, we have demonstrated that ribose crosslinking is cost-effective, safe and functionally effective. This study also offers new insights and opportunities in developing promising scaffolds for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Computing dispersion curves of elastic/viscoelastic transversely-isotropic bone plates coupled with soft tissue and marrow using semi-analytical finite element (SAFE) method.

    Science.gov (United States)

    Nguyen, Vu-Hieu; Tran, Tho N H T; Sacchi, Mauricio D; Naili, Salah; Le, Lawrence H

    2017-08-01

    We present a semi-analytical finite element (SAFE) scheme for accurately computing the velocity dispersion and attenuation in a trilayered system consisting of a transversely-isotropic (TI) cortical bone plate sandwiched between the soft tissue and marrow layers. The soft tissue and marrow are mimicked by two fluid layers of finite thickness. A Kelvin-Voigt model accounts for the absorption of all three biological domains. The simulated dispersion curves are validated by the results from the commercial software DISPERSE and published literature. Finally, the algorithm is applied to a viscoelastic trilayered TI bone model to interpret the guided modes of an ex-vivo experimental data set from a bone phantom. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. SU-F-J-174: A Series of Computational Human Phantoms in DICOM-RT Format for Normal Tissue Dose Reconstruction in Epidemiological Studies

    International Nuclear Information System (INIS)

    Pyakuryal, A; Moroz, B; Lee, C; Pelletier, C; Jung, J; Lee, C

    2016-01-01

    Purpose: Epidemiological studies of second cancer risk in radiotherapy patients often require individualized dose estimates of normal tissues. Prior to 3D conformal radiation therapy planning, patient anatomy information was mostly limited to 2D radiological images or not even available. Generic patient CT images are often used in commercial radiotherapy treatment planning system (TPS) to reconstruct normal tissue doses. The objective of the current work was to develop a series of reference size computational human phantoms in DICOM-RT format for direct use in dose reconstruction in TPS. Methods: Contours of 93 organs and tissues were extracted from a series of pediatric and adult hybrid computational human phantoms (newborn, 1-, 5-, 10-, 15-year-old, and adult males and females) using Rhinoceros software. A MATLAB script was created to convert the contours into the DICOM-RT structure format. The simulated CT images with the resolution of 1×1×3 mm3 were also generated from the binary phantom format and coupled with the DICOM-structure files. Accurate volumes of the organs were drawn in the format using precise delineation of the contours in converted format. Due to complex geometry of organs, higher resolution (1×1×1 mm3) was found to be more efficient in the conversion of newborn and 1-year-old phantoms. Results: Contour sets were efficiently converted into DICOM-RT structures in relatively short time (about 30 minutes for each phantom). A good agreement was observed in the volumes between the original phantoms and the converted contours for large organs (NRMSD<1.0%) and small organs (NRMSD<7.7%). Conclusion: A comprehensive series of computational human phantoms in DICOM-RT format was created to support epidemiological studies of second cancer risks in radiotherapy patients. We confirmed the DICOM-RT phantoms were successfully imported into the TPS programs of major vendors.

  10. SU-F-J-174: A Series of Computational Human Phantoms in DICOM-RT Format for Normal Tissue Dose Reconstruction in Epidemiological Studies

    Energy Technology Data Exchange (ETDEWEB)

    Pyakuryal, A; Moroz, B [National Cancer Institute, National Institutes of Health, Rockville, MD (United States); Lee, C [University of Michigan, Ann Arbor, MI (United States); Pelletier, C; Jung, J [East Carolina University Greenville, NC (United States); Lee, C [National Cancer Institute, Rockville, MD (United States)

    2016-06-15

    Purpose: Epidemiological studies of second cancer risk in radiotherapy patients often require individualized dose estimates of normal tissues. Prior to 3D conformal radiation therapy planning, patient anatomy information was mostly limited to 2D radiological images or not even available. Generic patient CT images are often used in commercial radiotherapy treatment planning system (TPS) to reconstruct normal tissue doses. The objective of the current work was to develop a series of reference size computational human phantoms in DICOM-RT format for direct use in dose reconstruction in TPS. Methods: Contours of 93 organs and tissues were extracted from a series of pediatric and adult hybrid computational human phantoms (newborn, 1-, 5-, 10-, 15-year-old, and adult males and females) using Rhinoceros software. A MATLAB script was created to convert the contours into the DICOM-RT structure format. The simulated CT images with the resolution of 1×1×3 mm3 were also generated from the binary phantom format and coupled with the DICOM-structure files. Accurate volumes of the organs were drawn in the format using precise delineation of the contours in converted format. Due to complex geometry of organs, higher resolution (1×1×1 mm3) was found to be more efficient in the conversion of newborn and 1-year-old phantoms. Results: Contour sets were efficiently converted into DICOM-RT structures in relatively short time (about 30 minutes for each phantom). A good agreement was observed in the volumes between the original phantoms and the converted contours for large organs (NRMSD<1.0%) and small organs (NRMSD<7.7%). Conclusion: A comprehensive series of computational human phantoms in DICOM-RT format was created to support epidemiological studies of second cancer risks in radiotherapy patients. We confirmed the DICOM-RT phantoms were successfully imported into the TPS programs of major vendors.

  11. Spin-neurons: A possible path to energy-efficient neuromorphic computers

    Energy Technology Data Exchange (ETDEWEB)

    Sharad, Mrigank; Fan, Deliang; Roy, Kaushik [School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2013-12-21

    Recent years have witnessed growing interest in the field of brain-inspired computing based on neural-network architectures. In order to translate the related algorithmic models into powerful, yet energy-efficient cognitive-computing hardware, computing-devices beyond CMOS may need to be explored. The suitability of such devices to this field of computing would strongly depend upon how closely their physical characteristics match with the essential computing primitives employed in such models. In this work, we discuss the rationale of applying emerging spin-torque devices for bio-inspired computing. Recent spin-torque experiments have shown the path to low-current, low-voltage, and high-speed magnetization switching in nano-scale magnetic devices. Such magneto-metallic, current-mode spin-torque switches can mimic the analog summing and “thresholding” operation of an artificial neuron with high energy-efficiency. Comparison with CMOS-based analog circuit-model of a neuron shows that “spin-neurons” (spin based circuit model of neurons) can achieve more than two orders of magnitude lower energy and beyond three orders of magnitude reduction in energy-delay product. The application of spin-neurons can therefore be an attractive option for neuromorphic computers of future.

  12. COMPUTING

    CERN Multimedia

    P. McBride

    It has been a very active year for the computing project with strong contributions from members of the global community. The project has focused on site preparation and Monte Carlo production. The operations group has begun processing data from P5 as part of the global data commissioning. Improvements in transfer rates and site availability have been seen as computing sites across the globe prepare for large scale production and analysis as part of CSA07. Preparations for the upcoming Computing Software and Analysis Challenge CSA07 are progressing. Ian Fisk and Neil Geddes have been appointed as coordinators for the challenge. CSA07 will include production tests of the Tier-0 production system, reprocessing at the Tier-1 sites and Monte Carlo production at the Tier-2 sites. At the same time there will be a large analysis exercise at the Tier-2 centres. Pre-production simulation of the Monte Carlo events for the challenge is beginning. Scale tests of the Tier-0 will begin in mid-July and the challenge it...

  13. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction During the past six months, Computing participated in the STEP09 exercise, had a major involvement in the October exercise and has been working with CMS sites on improving open issues relevant for data taking. At the same time operations for MC production, real data reconstruction and re-reconstructions and data transfers at large scales were performed. STEP09 was successfully conducted in June as a joint exercise with ATLAS and the other experiments. It gave good indication about the readiness of the WLCG infrastructure with the two major LHC experiments stressing the reading, writing and processing of physics data. The October Exercise, in contrast, was conducted as an all-CMS exercise, where Physics, Computing and Offline worked on a common plan to exercise all steps to efficiently access and analyze data. As one of the major results, the CMS Tier-2s demonstrated to be fully capable for performing data analysis. In recent weeks, efforts were devoted to CMS Computing readiness. All th...

  14. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion The Tier 0 infrastructure was able to repack and promptly reconstruct heavy-ion collision data. Two copies were made of the data at CERN using a large CASTOR disk pool, and the core physics sample was replicated ...

  15. COMPUTING

    CERN Multimedia

    I. Fisk

    2012-01-01

    Introduction Computing continued with a high level of activity over the winter in preparation for conferences and the start of the 2012 run. 2012 brings new challenges with a new energy, more complex events, and the need to make the best use of the available time before the Long Shutdown. We expect to be resource constrained on all tiers of the computing system in 2012 and are working to ensure the high-priority goals of CMS are not impacted. Heavy ions After a successful 2011 heavy-ion run, the programme is moving to analysis. During the run, the CAF resources were well used for prompt analysis. Since then in 2012 on average 200 job slots have been used continuously at Vanderbilt for analysis workflows. Operations Office As of 2012, the Computing Project emphasis has moved from commissioning to operation of the various systems. This is reflected in the new organisation structure where the Facilities and Data Operations tasks have been merged into a common Operations Office, which now covers everything ...

  16. COMPUTING

    CERN Multimedia

    M. Kasemann

    CCRC’08 challenges and CSA08 During the February campaign of the Common Computing readiness challenges (CCRC’08), the CMS computing team had achieved very good results. The link between the detector site and the Tier0 was tested by gradually increasing the number of parallel transfer streams well beyond the target. Tests covered the global robustness at the Tier0, processing a massive number of very large files and with a high writing speed to tapes.  Other tests covered the links between the different Tiers of the distributed infrastructure and the pre-staging and reprocessing capacity of the Tier1’s: response time, data transfer rate and success rate for Tape to Buffer staging of files kept exclusively on Tape were measured. In all cases, coordination with the sites was efficient and no serious problem was found. These successful preparations prepared the ground for the second phase of the CCRC’08 campaign, in May. The Computing Software and Analysis challen...

  17. COMPUTING

    CERN Multimedia

    I. Fisk

    2010-01-01

    Introduction The first data taking period of November produced a first scientific paper, and this is a very satisfactory step for Computing. It also gave the invaluable opportunity to learn and debrief from this first, intense period, and make the necessary adaptations. The alarm procedures between different groups (DAQ, Physics, T0 processing, Alignment/calibration, T1 and T2 communications) have been reinforced. A major effort has also been invested into remodeling and optimizing operator tasks in all activities in Computing, in parallel with the recruitment of new Cat A operators. The teams are being completed and by mid year the new tasks will have been assigned. CRB (Computing Resource Board) The Board met twice since last CMS week. In December it reviewed the experience of the November data-taking period and could measure the positive improvements made for the site readiness. It also reviewed the policy under which Tier-2 are associated with Physics Groups. Such associations are decided twice per ye...

  18. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the co...

  19. An exploratory study of contrast agents for soft tissue visualization by means of high resolution X-ray computed tomography imaging.

    Science.gov (United States)

    Pauwels, E; Van Loo, D; Cornillie, P; Brabant, L; Van Hoorebeke, L

    2013-04-01

    High resolution X-ray computed tomography (CT), or microCT, is a promising and already widely used technique in various scientific fields. Also for histological purposes it has great potential. Although microCT has proven to be a valuable technique for the imaging of bone structures, the visualization of soft tissue structures is still an important challenge due to their low inherent X-ray contrast. One way to achieve contrast enhancement is to make use of contrast agents. However, contrary to light and electron microscopy, knowledge about contrast agents and staining procedures is limited for X-ray CT. The purpose of this paper is to identify useful X-ray contrast agents for soft tissue visualization, which can be applied in a simple way and are also suited for samples larger than (1 cm)(3) . And 28 chemical substances have been investigated. All chemicals were applied in the form of concentrated aqueous solutions in which the samples were immersed. First, strips of green Bacon were stained to evaluate contrast enhancement between muscle and adipose tissue. Furthermore it was also tested whether the contrast agents remained fixed in the tissue after staining by re-immersing them in water. Based on the results, 12 contrast agents were selected for further testing on postmortem mice hind legs, containing a variety of different tissues, including muscle, fat, bone, cartilage and tendons. It was evaluated whether the contrast agents allowed a clearer distinction between the different soft tissue structures present. Finally also penetration depth was measured. And 26 chemicals resulted in contrast enhancement between muscle and adipose tissue in the Bacon strips. Mercury(II)chloride (HgCl2 ), phosphotungstic acid (PTA), phosphomolybdic acid (PMA) and ammonium orthomolybdate ((NH4 )2 MoO4 ) remained fixed after re-immersion in water. The penetration tests showed that potassium iodide (KI) and sodium tungstate can be most efficiently used for large samples of the order

  20. Assessing accumulated hard-tissue debris using micro-computed tomography and free software for image processing and analysis.

    Science.gov (United States)

    De-Deus, Gustavo; Marins, Juliana; Neves, Aline de Almeida; Reis, Claudia; Fidel, Sandra; Versiani, Marco A; Alves, Haimon; Lopes, Ricardo Tadeu; Paciornik, Sidnei

    2014-02-01

    The accumulation of debris occurs after root canal preparation procedures specifically in fins, isthmus, irregularities, and ramifications. The aim of this study was to present a step-by-step description of a new method used to longitudinally identify, measure, and 3-dimensionally map the accumulation of hard-tissue debris inside the root canal after biomechanical preparation using free software for image processing and analysis. Three mandibular molars presenting the mesial root with a large isthmus width and a type II Vertucci's canal configuration were selected and scanned. The specimens were assigned to 1 of 3 experimental approaches: (1) 5.25% sodium hypochlorite + 17% EDTA, (2) bidistilled water, and (3) no irrigation. After root canal preparation, high-resolution scans of the teeth were accomplished, and free software packages were used to register and quantify the amount of accumulated hard-tissue debris in either canal space or isthmus areas. Canal preparation without irrigation resulted in 34.6% of its volume filled with hard-tissue debris, whereas the use of bidistilled water or NaOCl followed by EDTA showed a reduction in the percentage volume of debris to 16% and 11.3%, respectively. The closer the distance to the isthmus area was the larger the amount of accumulated debris regardless of the irrigating protocol used. Through the present method, it was possible to calculate the volume of hard-tissue debris in the isthmuses and in the root canal space. Free-software packages used for image reconstruction, registering, and analysis have shown to be promising for end-user application. Copyright © 2014. Published by Elsevier Inc.