WorldWideScience

Sample records for controlled on-chip stimulation

  1. Phagocytic response to fully controlled plural stimulation of antigens on macrophage using on-chip microcultivation system

    Directory of Open Access Journals (Sweden)

    Wakamoto Yuichi

    2006-08-01

    Full Text Available Abstract To understand the control mechanism of innate immune response in macrophages, a series of phagocytic responses to plural stimulation of antigens on identical cells was observed. Two zymosan particles, which were used as antigens, were put on different surfaces of a macrophage using optical tweezers in an on-chip single-cell cultivation system, which maintains isolated conditions of each macrophage during their cultivation. When the two zymosan particles were attached to the macrophage simultaneously, the macrophage responded and phagocytosed both of the antigens simultaneously. In contrast, when the second antigen was attached to the surface after the first phagocytosis had started, the macrophage did not respond to the second stimulation during the first phagocytosis; the second phagocytosis started only after the first process had finished. These results indicate that (i phagocytosis in a macrophage is not an independent process when there are plural stimulations; (ii the response of the macrophage to the second stimulation is related to the time" delay from the first stimulation. Stimulations that occur at short time intervals resulted in simultaneous phagocytosis, while a second stimulation that is delayed long enough might be neglected until the completion of the first phagocytic process.

  2. Fuzzy logic controllers on chip

    OpenAIRE

    Acosta, Nelson; Simonelli, Daniel Horacio

    2002-01-01

    This paper analyzes a fuzzy logic (FL) oriented instruction set (micro)controller and their implementations on FIPSOC1. VHDL code is synthesized using a small portion of FIPSOC FPGA2. This circuits are used from the mP8051 FIPSOC built-in microcontroller to provide efficient arithmetic operations such as multipliers, dividers, minimums and maximums.

  3. Transient and permanent error control for networks-on-chip

    CERN Document Server

    Yu, Qiaoyan

    2012-01-01

    This book addresses reliability and energy efficiency of on-chip networks using a configurable error control coding (ECC) scheme for datalink-layer transient error management. The method can adjust both error detection and correction strengths at runtime by varying the number of redundant wires for parity-check bits. Methods are also presented to tackle joint transient and permanent error correction, exploiting the redundant resources already available on-chip. A parallel and flexible network simulator is also introduced, which facilitates examining the impact of various error control methods on network-on-chip performance. Includes a complete survey of error control methods for reliable networks-on-chip, evaluated for reliability, energy and performance metrics; Provides analysis of error control in various network-on-chip layers, as well as presentation of an innovative multi-layer error control coding technique; Presents state-of-the-art solutions to address simultaneously reliability, energy and performan...

  4. Error Control for Network-on-Chip Links

    CERN Document Server

    Fu, Bo

    2012-01-01

    As technology scales into nanoscale regime, it is impossible to guarantee the perfect hardware design. Moreover, if the requirement of 100% correctness in hardware can be relaxed, the cost of manufacturing, verification, and testing will be significantly reduced. Many approaches have been proposed to address the reliability problem of on-chip communications. This book focuses on the use of error control codes (ECCs) to improve on-chip interconnect reliability. Coverage includes detailed description of key issues in NOC error control faced by circuit and system designers, as well as practical error control techniques to minimize the impact of these errors on system performance. Provides a detailed background on the state of error control methods for on-chip interconnects; Describes the use of more complex concatenated codes such as Hamming Product Codes with Type-II HARQ, while emphasizing integration techniques for on-chip interconnect links; Examines energy-efficient techniques for integrating multiple error...

  5. Synthesis of on-chip control circuits for mVLSI biochips

    DEFF Research Database (Denmark)

    Potluri, Seetal; Schneider, Alexander Rüdiger; Hørslev-Petersen, Martin

    2017-01-01

    them to laboratory environments. To address this issue, researchers have proposed methods to reduce the number of offchip pressure sources, through integration of on-chip pneumatic control logic circuits fabricated using three-layer monolithic membrane valve technology. Traditionally, mVLSI biochip...... applied to generate biochip layouts with integrated on-chip pneumatic control....

  6. Technology for On-Chip Qubit Control with Microfabricated Surface Ion Traps

    Energy Technology Data Exchange (ETDEWEB)

    Highstrete, Clark [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Quantum Information Sciences Dept.; Scott, Sean Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). RF/Optoelectronics Dept.; Nordquist, Christopher D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). RF/Optoelectronics Dept.; Sterk, Jonathan David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photonic Microsystem Technologies Dept.; Maunz, Peter Lukas Wilhelm [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photonic Microsystem Technologies Dept.; Tigges, Christopher P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photonic Microsystem Technologies Dept.; Blain, Matthew Glenn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photonic Microsystem Technologies Dept.; Heller, Edwin J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Microsystems Integration Dept.; Stevens, James E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). MESAFab Operations 2 Dept.

    2013-11-01

    Trapped atomic ions are a leading physical system for quantum information processing. However, scalability and operational fidelity remain limiting technical issues often associated with optical qubit control. One promising approach is to develop on-chip microwave electronic control of ion qubits based on the atomic hyperfine interaction. This project developed expertise and capabilities at Sandia toward on-chip electronic qubit control in a scalable architecture. The project developed a foundation of laboratory capabilities, including trapping the 171Yb+ hyperfine ion qubit and developing an experimental microwave coherent control capability. Additionally, the project investigated the integration of microwave device elements with surface ion traps utilizing Sandia’s state-of-the-art MEMS microfabrication processing. This effort culminated in a device design for a multi-purpose ion trap experimental platform for investigating on-chip microwave qubit control, laying the groundwork for further funded R&D to develop on-chip microwave qubit control in an architecture that is suitable to engineering development.

  7. A programmable and configurable multi-port System-on-Chip for stimulating electrokinetically-driven microfluidic devices.

    Science.gov (United States)

    Lopez, Martha Salome; Gerstlauer, Andreas; Avila, Alfonso; Martinez-Chapa, Sergio O

    2011-01-01

    Recent research has demonstrated the use of microfluidic devices and electro-kinetics in areas such as medicine, genetics, embryology, epidemiology and pollution analysis, where manipulation of particles suspended in liquid media is required. Micro-fabrication technology has made it possible to increase system complexity and functionality by allowing integration of different processing and analysis stages in a single chip. However, fully integrated and autonomous microfluidic systems supporting ad-hoc stimulation have yet to be developed. This paper presents a flexible, configurable and programmable stimulator for electro-kinetically driven microfluidic devices. The stimulator is a dedicated System-on-Chip (SoC) architecture that generates sine, triangle, and sawtooth signals within a frequency range of 1 Hz to 20 MHz, capable of delivering single, dual, and superimposed waveforms, in a user defined test sequence for a selected time period. The system is designed to be integrated into complete, autonomous Lab-on-Chip, portable or implantable devices. As such, it is expected to help significantly advance current and future research on particle manipulation.

  8. Micro, nanosystems and systems on chips modeling, control, and estimation

    CERN Document Server

    Voda, Alina

    2013-01-01

    Micro and nanosystems represent a major scientific and technological challenge, with actual and potential applications in almost all fields of the human activity. The aim of the present book is to present how concepts from dynamical control systems (modeling, estimation, observation, identification, feedback control) can be adapted and applied to the development of original very small-scale systems and of their human interfaces. The application fields presented here come from micro and nanorobotics, biochips, near-field microscopy (AFM and STM) and nanosystems networks. Alina Voda has drawn co

  9. On-Chip Flow Control for 2-PhaseNanofluidics

    NARCIS (Netherlands)

    Shui, Lingling; Berg, van den Albert; Eijkel, Jan C.T.; Kim, Tae Song; Lee, Yoon-Sik; Chung, Twek-Dong; Jeon, Noo Li; Lee, Sang-Hoon; Suh, Kahp-Yang; Choo, Jaebm; Kim, Yong-Kweon

    2009-01-01

    We developed a novel method to control two-phase flow in nanochannels using regulating microchannels connected to the nanochannels. The flow rate inside a nanochannel can be regulated based on the pressure drops along the channel network. Stable flows with flow rates as low as 10-5 µL.min-1 (< pL.s-

  10. On-chip generation and control of the vortex beam

    CERN Document Server

    Liu, Aiping; Ren, Xifeng; Wang, Qin; Guo, Guang-Can

    2015-01-01

    A new method to generate and control the amplitude and phase distributions of a optical vortex beam is proposed. By introducing a holographic grating on top of the dielectric waveguide, the free space vortex beam and the in-plane guiding wave can be converted to each other. This microscale holographic grating is very robust against the variation of geometry parameters. The designed vortex beam generator can produce the target beam with a fidelity up to 0.93, and the working bandwidth is about 175 nm with the fidelity larger than 0.80. In addition, a multiple generator composed of two holographic gratings on two parallel waveguides are studied, which can perform an effective and flexible modulation on the vortex beam by controlling the phase of the input light. Our work opens a new avenue towards the integrated OAM devices with multiple degrees of optical freedom, which can be used for optical tweezers, micronano imaging, information processing, and so on.

  11. On-chip generation and control of the vortex beam

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Aiping; Wang, Qin [College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu 210000, China and Key Lab of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003 (China); Zou, Chang-Ling, E-mail: clzou321@ustc.edu.cn [Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Department of Electric Engineering, Yale University, New Haven, Connecticut 06511 (United States); Ren, Xifeng, E-mail: renxf@ustc.edu.cn; Guo, Guang-Can [Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2016-05-02

    A method to generate and control the amplitude and phase distributions of an optical vortex beam is proposed. By introducing a holographic grating on the top of a dielectric waveguide, the free space vortex beam and the in-plane guiding wave can be converted to each other. This microscale holographic grating is very robust against the variation of geometry parameters. The designed vortex beam generator can produce the target beam with a fidelity up to 0.93, and the working bandwidth is about 175 nm with the fidelity larger than 0.80. In addition, a multiple generator composed of two holographic gratings on two parallel waveguides is studied, which can perform an effective and flexible modulation on the vortex beam by controlling the phase of the input light. Our work opens an available avenue towards the integrated orbital angular momentum devices with multiple degrees of optical freedom, which can be used for optical tweezers, micronano imaging, information processing, and so on.

  12. On-Chip AC self-test controller

    Science.gov (United States)

    Flanagan, John D.; Herring, Jay R.; Lo, Tin-Chee

    2009-09-29

    A system for performing AC self-test on an integrated circuit that includes a system clock for normal operation is provided. The system includes the system clock, self-test circuitry, a first and second test register to capture and launch test data in response to a sequence of data pulses, and a logic circuit to be tested. The self-test circuitry includes an AC self-test controller and a clock splitter. The clock splitter generates the sequence of data pulses including a long data capture pulse followed by an at speed data launch pulse and an at speed data capture pulse followed by a long data launch pulse. The at speed data launch pulse and the at speed data capture pulse are generated for a common cycle of the system clock.

  13. Robust thermal control for CMOS-based lab-on-chip systems

    Science.gov (United States)

    Martinez-Quijada, Jose; Ma, Tianchi; Hall, Gordon H.; Reynolds, Matt; Sloan, David; Caverhill-Godkewitsch, Saul; Glerum, D. Moira; Sameoto, Dan; Elliott, Duncan G.; Backhouse, Christopher J.

    2015-07-01

    The need for precise temperature control at small scales has provided a formidable challenge to the lab-on-chip community. It requires, at once, good thermal conductivity for high speed operation, good thermal isolation for low power consumption and the ability to have small (mm-scale) thermally independent regions on the same substrate. Most importantly, and, in addition to these conflicting requirements, there is a need to accurately measure the temperature of the active region without the need for device-to-device calibrations. We have developed and tested a design that enables thermal control of lab-on-chip devices atop silicon substrates in a way that could be integrated with the standard methods of mass-manufacture used in the electronics industry (i.e. CMOS). This is a significant step towards a single-chip lab-on-chip solution, one in which the microfluidics, high voltage electronics, optoelectronics, instrumentation electronics, and the world-chip interface are all integrated on a single substrate with multiple, independent, thermally-controlled regions based on active heating and passive cooling.

  14. On-chip microrobot for investigating the response of aquatic microorganisms to mechanical stimulation.

    Science.gov (United States)

    Kawahara, Tomohiro; Sugita, Masakuni; Hagiwara, Masaya; Arai, Fumihito; Kawano, Hiroyuki; Shihira-Ishikawa, Ikuko; Miyawaki, Atsushi

    2013-03-21

    In this paper, we propose a novel, magnetically driven microrobot equipped with a frame structure to measure the effects of stimulating aquatic microorganisms. The design and fabrication of the force-sensing structure with a displacement magnification mechanism based on beam deformation are described. The microrobot is composed of a Si-Ni hybrid structure constructed using micro-electro-mechanical system (MEMS) technologies. The microrobots with 5 μm-wide force sensors are actuated in a microfluidic chip by permanent magnets so that they can locally stimulate the microorganisms with the desired force within the stable environment of the closed microchip. They afford centimetre-order mobility (untethered drive) and millinewton-order forces (high power) as well as force-sensing. Finally, we apply the developed microrobots for the quantitative evaluation of the stimuation of Pleurosira laevis (P. laevis) and determine the relationship between the applied force and the response of a single cell.

  15. An Efficient Radio Access Control Mechanism for Wireless Network-On-Chip Architectures

    Directory of Open Access Journals (Sweden)

    Maurizio Palesi

    2015-03-01

    Full Text Available Modern systems-on-chip (SoCs today contain hundreds of cores, and this number is predicted to reach the thousands by the year 2020. As the number of communicating elements increases, there is a need for an efficient, scalable and reliable communication infrastructure. As technology geometries shrink to the deep submicron regime, however, the communication delay and power consumption of global interconnections become the major bottleneck. The network-on-chip (NoC design paradigm, based on a modular packet-switched mechanism, can address many of the on-chip communication issues, such as the performance limitations of long interconnects and integration of large number of cores on a chip. Recently, new communication technologies based on the NoC concept have emerged with the aim of improving the scalability limitations of conventional NoC-based architectures. Among them, wireless NoCs (WiNoCs use the radio medium for reducing the performance and energy penalties of long-range and multi-hop communications. As the radio medium can be accessed by a single transmitter at a time, a radio access control mechanism (RACM is needed. In this paper, we present a novel RACM, which allows one to improve both the performance and energy figures of the WiNoC. Experiments, carried out on both synthetic and real traffic scenarios, have shown the effectiveness of the proposed RACM. On average, a 30% reduction in communication delay and a 25% energy savings have been observed when the proposed RACM is applied to a known WiNoC architecture.

  16. Heteronanojunctions with atomic size control using a lab-on-chip electrochemical approach with integrated microfluidics.

    Science.gov (United States)

    Lunca Popa, P; Dalmas, G; Faramarzi, V; Dayen, J F; Majjad, H; Kemp, N T; Doudin, B

    2011-05-27

    A versatile tool for electrochemical fabrication of heteronanojunctions with nanocontacts made of a few atoms and nanogaps of molecular spacing is presented. By integrating microfluidic circuitry in a lab-on-chip approach, we keep control of the electrochemical environment in the vicinity of the nanojunction and add new versatility for exchanging and controlling the junction's medium. Nanocontacts made of various materials by successive local controlled depositions are demonstrated, with electrical properties revealing sizes reaching a few atoms only. Investigations on benchmark molecular electronics material, trapped between electrodes, reveal the possibility to create nanogaps of size matching those of molecules. We illustrate the interest of a microfluidic approach by showing that exposure of a fabricated molecular junction to controlled high solvent flows can be used as a reliability criterion for the presence of molecular entities in a gap.

  17. Controlling Differentiation of Stem Cells for Developing Personalized Organ-on-Chip Platforms.

    Science.gov (United States)

    Geraili, Armin; Jafari, Parya; Hassani, Mohsen Sheikh; Araghi, Behnaz Heidary; Mohammadi, Mohammad Hossein; Ghafari, Amir Mohammad; Tamrin, Sara Hasanpour; Modarres, Hassan Pezeshgi; Kolahchi, Ahmad Rezaei; Ahadian, Samad; Sanati-Nezhad, Amir

    2017-09-14

    Organ-on-chip (OOC) platforms have attracted attentions of pharmaceutical companies as powerful tools for screening of existing drugs and development of new drug candidates. OOCs have primarily used human cell lines or primary cells to develop biomimetic tissue models. However, the ability of human stem cells in unlimited self-renewal and differentiation into multiple lineages has made them attractive for OOCs. The microfluidic technology has enabled precise control of stem cell differentiation using soluble factors, biophysical cues, and electromagnetic signals. This study discusses different tissue- and organ-on-chip platforms (i.e., skin, brain, blood-brain barrier, bone marrow, heart, liver, lung, tumor, and vascular), with an emphasis on the critical role of stem cells in the synthesis of complex tissues. This study further recaps the design, fabrication, high-throughput performance, and improved functionality of stem-cell-based OOCs, technical challenges, obstacles against implementing their potential applications, and future perspectives related to different experimental platforms. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. On-Chip Hotplate for Temperature Control of Cmos Saw Resonators

    CERN Document Server

    Nordin, Anis; Zaghloul, Mona

    2008-01-01

    Due to the sensitivity of the piezoelectric layer in surface acoustic wave (SAW) resonators to temperature, a method of achieving device stability as a function of temperature is required. This work presents the design, modeling and characterization of integrated dual-serpentine polysilicon resistors as a method for temperature control of CMOS SAW resonators. The design employs the oven control temperature stabilization scheme where the device's temperature is elevated to higher than Tmax to maintain constant device temperature. The efficiency of the polysilicon resistor as a heating element was verified through a 1-D partial differential equation model, 3-D CoventorWare finite element simulations and measurements using Compix thermal camera. To verify that the on-chip hotplate is effective as a temperature control method, both DC and RF measurements of the heater together with the resonator were conducted. Experimental results have indicated that the TCF of the CMOS SAW resonator of -97.2 ppm/deg C has been ...

  19. Adaptive on-chip control of nano-optical fields with optoplasmonic vortex nanogates

    CERN Document Server

    Boriskina, Svetlana V

    2011-01-01

    A major challenge for plasmonics as an enabling technology for quantum information processing is the realization of active spatio-temporal control of light on the nanoscale. The use of phase-shaped pulses or beams enforces specific requirements for on-chip integration and imposes strict design limitations. We introduce here an alternative approach, which is based on exploiting the strong sub-wavelength spatial phase modulation in the near-field of resonantly-excited high-Q optical microcavities integrated into plasmonic nanocircuits. Our theoretical analysis reveals the formation of areas of circulating powerflow (optical vortices) in the near-fields of optical microcavities, whose positions and mutual coupling can be controlled by tuning the microcavities parameters and the excitation wavelength. We show that optical powerflow though nanoscale plasmonic structures can be dynamically molded by engineering interactions of microcavity-induced optical vortices with noble-metal nanoparticles. The proposed strateg...

  20. A Novel Architecture for Adaptive Traffic Control in Network on Chip using Code Division Multiple Access Technique

    Directory of Open Access Journals (Sweden)

    Fatemeh. Dehghani

    2016-08-01

    Full Text Available Network on chip has emerged as a long-term and effective method in Multiprocessor System-on-Chip communications in order to overcome the bottleneck in bus based communication architectures. Efficiency and performance of network on chip is so dependent on the architecture and structure of the network. In this paper a new structure and architecture for adaptive traffic control in network on chip using Code Division Multiple Access technique is presented. To solve the problem of synchronous access to bus based interconnection the code division multiple access technique was applied. In the presented structure that is based upon mesh topology and simple routing method we attempted to increase the exchanged data bandwidth rate among different cores. Also an attempt has been made to increase the performance by isolating the target address transfer path from data transfer path. The main goal of this paper is presenting a new structure to improve energy consumption, area and maximum frequency in network on chip systems using information coding and decoding techniques. The presented structure is simulated using Xilinx ISE software and the results show effectiveness of this architecture.

  1. On-chip electrically controlled routing of photons from a single quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Bentham, C.; Coles, R. J.; Royall, B.; O' Hara, J.; Prtljaga, N.; Fox, A. M.; Skolnick, M. S.; Wilson, L. R. [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom); Itskevich, I. E., E-mail: I.Itskevich@hull.ac.uk [School of Engineering, University of Hull, Hull HU6 7RX (United Kingdom); Clarke, E. [Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2015-06-01

    Electrical control of on-chip routing of photons emitted by a single InAs/GaAs self-assembled quantum dot (SAQD) is demonstrated in a photonic crystal cavity-waveguide system. The SAQD is located inside an H1 cavity, which is coupled to two photonic crystal waveguides. The SAQD emission wavelength is electrically tunable by the quantum-confined Stark effect. When the SAQD emission is brought into resonance with one of two H1 cavity modes, it is preferentially routed to the waveguide to which that mode is selectively coupled. This proof of concept provides the basis for scalable, low-power, high-speed operation of single-photon routers for use in integrated quantum photonic circuits.

  2. On-chip boost regulator with projected off- and on-time control*

    Institute of Scientific and Technical Information of China (English)

    Xiao-ru XU; Meng-lian ZHAO; Xiao-bo WU

    2009-01-01

    The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode (LED) driving and liquid crystal display (LCD) biasing. In these applications, a regulator with small volume, fewer external components and high efficiency is highly desired. This paper proposes a projected off- and on-time boost control scheme, based on which a monolithic IC with an on-chip VDMOS with 0.2 Ω on-stateresistance RDS-ON was implemented in 1.5 μm bipolar-CMOS-DMOS (BCD) process. A 12V, 0.3A boost regulator prototype ispresented as well. With projected off-time and modulated on-time in continuous conduction mode (CCM), a quasi fixed frequency,which is preferred for ripple control, is realized. With projected on-time and modulated off-time in discontinuous conduction mode (DCM), pulse frequency modulation (PFM) operation, which is beneficial to light load efficiency improvement, is achieved without extra control circuitry. Measurement results show that an efficiency of 3% higher than that of a conventional method under 0.5 W output is achieved while a step load transient response comparable to that of current mode control is maintained as well.

  3. Engineering challenges for instrumenting and controlling integrated organ-on-chip systems.

    Science.gov (United States)

    Wikswo, John P; Block, Frank E; Cliffel, David E; Goodwin, Cody R; Marasco, Christina C; Markov, Dmitry A; McLean, David L; McLean, John A; McKenzie, Jennifer R; Reiserer, Ronald S; Samson, Philip C; Schaffer, David K; Seale, Kevin T; Sherrod, Stacy D

    2013-03-01

    The sophistication and success of recently reported microfabricated organs-on-chips and human organ constructs have made it possible to design scaled and interconnected organ systems that may significantly augment the current drug development pipeline and lead to advances in systems biology. Physiologically realistic live microHuman (μHu) and milliHuman (mHu) systems operating for weeks to months present exciting and important engineering challenges such as determining the appropriate size for each organ to ensure appropriate relative organ functional activity, achieving appropriate cell density, providing the requisite universal perfusion media, sensing the breadth of physiological responses, and maintaining stable control of the entire system, while maintaining fluid scaling that consists of ~5 mL for the mHu and ~5 μL for the μHu. We believe that successful mHu and μHu systems for drug development and systems biology will require low-volume microdevices that support chemical signaling, microfabricated pumps, valves and microformulators, automated optical microscopy, electrochemical sensors for rapid metabolic assessment, ion mobility-mass spectrometry for real-time molecular analysis, advanced bioinformatics, and machine learning algorithms for automated model inference and integrated electronic control. Toward this goal, we are building functional prototype components and are working toward top-down system integration.

  4. Morphological control via chemical and shear forces in block copolymer self-assembly in the lab-on-chip.

    Science.gov (United States)

    Wang, Chih-Wei; Sinton, David; Moffitt, Matthew G

    2013-02-26

    We investigate the effects of variation in chemical conditions (solvent composition, water content, polymer concentration, and added salt) on the morphologies formed by PS-b-PAA in DMF/dioxane/water mixtures in a two-phase gas-liquid segmented microfluidic reactor. The differences in morphologies between off-chip and on-chip self-assembly and on-chip morphological trends for different chemical conditions are explained by the interplay of top-down shear effects (coalescence and breakup) and bottom-up chemical forces. Using off-chip morphology results, we construct a water content-solvent composition phase diagram showing disordered, sphere, cylinder, and vesicle regions. On-chip morphologies are found to deviate from off-chip morphologies by three identified shear-induced paths: 1) sphere-to-cylinder, and 2) sphere-to-vesicle transitions, both via shear-induced coalescence when initial micelle sizes are small, and 3) cylinder-to-sphere transitions via shear-induced breakup when initial micelle sizes are large (high capillary number conditions). These pathways contribute to the generation of large extended bilayer aggregates uniquely on-chip, at either increased polymer or salt concentrations. Collectively these results demonstrate the broad utility of top-down directed molecular self-assembly in conjunction with chemical forces to control morphology and size of polymer colloids at the nanoscale.

  5. The System Power Control Unit Based on the On-Chip Wireless Communication System

    Directory of Open Access Journals (Sweden)

    Tiefeng Li

    2013-01-01

    Full Text Available Currently, the on-chip wireless communication system (OWCS includes 2nd-generation (2G, 3rd-generation (3G, and long-term evolution (LTE communication subsystems. To improve the power consumption of OWCS, a typical architecture design of system power control unit (SPCU is given in this paper, which can not only make a 2G, a 3G, and an LTE subsystems enter sleep mode, but it can also wake them up from sleep mode via the interrupt. During the sleep mode period, either the real-time sleep timer or the global system for mobile (GSM communication sleep timer can be used individually to arouse the corresponding subsystem. Compared to previous sole voltage supplies on the OWCS, a 2G, a 3G, or an LTE subsystem can be independently configured with three different voltages and frequencies in normal work mode. In the meantime, the voltage supply monitor, which is an important part in the SPCU, can significantly guard the voltage of OWCS in real time. Finally, the SPCU may implement dynamic voltage and frequency scaling (DVFS for a 2G, a 3G, or an LTE subsystem, which is automatically accomplished by the hardware.

  6. The System Power Control Unit Based on the On-Chip Wireless Communication System

    Science.gov (United States)

    Li, Tiefeng; Ma, Caiwen; Li, WenHua

    2013-01-01

    Currently, the on-chip wireless communication system (OWCS) includes 2nd-generation (2G), 3rd-generation (3G), and long-term evolution (LTE) communication subsystems. To improve the power consumption of OWCS, a typical architecture design of system power control unit (SPCU) is given in this paper, which can not only make a 2G, a 3G, and an LTE subsystems enter sleep mode, but it can also wake them up from sleep mode via the interrupt. During the sleep mode period, either the real-time sleep timer or the global system for mobile (GSM) communication sleep timer can be used individually to arouse the corresponding subsystem. Compared to previous sole voltage supplies on the OWCS, a 2G, a 3G, or an LTE subsystem can be independently configured with three different voltages and frequencies in normal work mode. In the meantime, the voltage supply monitor, which is an important part in the SPCU, can significantly guard the voltage of OWCS in real time. Finally, the SPCU may implement dynamic voltage and frequency scaling (DVFS) for a 2G, a 3G, or an LTE subsystem, which is automatically accomplished by the hardware. PMID:23818835

  7. The system power control unit based on the on-chip wireless communication system.

    Science.gov (United States)

    Li, Tiefeng; Ma, Caiwen; Li, WenHua

    2013-01-01

    Currently, the on-chip wireless communication system (OWCS) includes 2nd-generation (2G), 3rd-generation (3G), and long-term evolution (LTE) communication subsystems. To improve the power consumption of OWCS, a typical architecture design of system power control unit (SPCU) is given in this paper, which can not only make a 2G, a 3G, and an LTE subsystems enter sleep mode, but it can also wake them up from sleep mode via the interrupt. During the sleep mode period, either the real-time sleep timer or the global system for mobile (GSM) communication sleep timer can be used individually to arouse the corresponding subsystem. Compared to previous sole voltage supplies on the OWCS, a 2G, a 3G, or an LTE subsystem can be independently configured with three different voltages and frequencies in normal work mode. In the meantime, the voltage supply monitor, which is an important part in the SPCU, can significantly guard the voltage of OWCS in real time. Finally, the SPCU may implement dynamic voltage and frequency scaling (DVFS) for a 2G, a 3G, or an LTE subsystem, which is automatically accomplished by the hardware.

  8. On-chip artificial magnon-polariton device for voltage control of electromagnetically induced transparency

    Science.gov (United States)

    Kaur, Sandeep; Yao, Bimu; Gui, Yong-Sheng; Hu, Can-Ming

    2016-11-01

    We demonstrate an on-chip device utilizing the concept of an artificial cavity magnon-polariton (CMP) generated via coupling between a microwave cavity mode and the artificial magnetism dynamics of a split ring resonator. This on-chip device allows the easy tuning of the artificial CMP gap by using a DC voltage signal, which enables tuneable electrodynamically induced transparency. The high tunability of the artificial magnon-polariton system not only enables the study of phenomena associated with the classical analogues of different coupling regimes, but also may open up avenues for designing advanced microwave devices and ultra-sensitive sensors.

  9. On-chip generation of high-dimensional entangled quantum states and their coherent control

    Science.gov (United States)

    Kues, Michael; Reimer, Christian; Roztocki, Piotr; Cortés, Luis Romero; Sciara, Stefania; Wetzel, Benjamin; Zhang, Yanbing; Cino, Alfonso; Chu, Sai T.; Little, Brent E.; Moss, David J.; Caspani, Lucia; Azaña, José; Morandotti, Roberto

    2017-06-01

    Optical quantum states based on entangled photons are essential for solving questions in fundamental physics and are at the heart of quantum information science. Specifically, the realization of high-dimensional states (D-level quantum systems, that is, qudits, with D > 2) and their control are necessary for fundamental investigations of quantum mechanics, for increasing the sensitivity of quantum imaging schemes, for improving the robustness and key rate of quantum communication protocols, for enabling a richer variety of quantum simulations, and for achieving more efficient and error-tolerant quantum computation. Integrated photonics has recently become a leading platform for the compact, cost-efficient, and stable generation and processing of non-classical optical states. However, so far, integrated entangled quantum sources have been limited to qubits (D = 2). Here we demonstrate on-chip generation of entangled qudit states, where the photons are created in a coherent superposition of multiple high-purity frequency modes. In particular, we confirm the realization of a quantum system with at least one hundred dimensions, formed by two entangled qudits with D = 10. Furthermore, using state-of-the-art, yet off-the-shelf telecommunications components, we introduce a coherent manipulation platform with which to control frequency-entangled states, capable of performing deterministic high-dimensional gate operations. We validate this platform by measuring Bell inequality violations and performing quantum state tomography. Our work enables the generation and processing of high-dimensional quantum states in a single spatial mode.

  10. On-chip generation of high-dimensional entangled quantum states and their coherent control.

    Science.gov (United States)

    Kues, Michael; Reimer, Christian; Roztocki, Piotr; Cortés, Luis Romero; Sciara, Stefania; Wetzel, Benjamin; Zhang, Yanbing; Cino, Alfonso; Chu, Sai T; Little, Brent E; Moss, David J; Caspani, Lucia; Azaña, José; Morandotti, Roberto

    2017-06-28

    Optical quantum states based on entangled photons are essential for solving questions in fundamental physics and are at the heart of quantum information science. Specifically, the realization of high-dimensional states (D-level quantum systems, that is, qudits, with D > 2) and their control are necessary for fundamental investigations of quantum mechanics, for increasing the sensitivity of quantum imaging schemes, for improving the robustness and key rate of quantum communication protocols, for enabling a richer variety of quantum simulations, and for achieving more efficient and error-tolerant quantum computation. Integrated photonics has recently become a leading platform for the compact, cost-efficient, and stable generation and processing of non-classical optical states. However, so far, integrated entangled quantum sources have been limited to qubits (D = 2). Here we demonstrate on-chip generation of entangled qudit states, where the photons are created in a coherent superposition of multiple high-purity frequency modes. In particular, we confirm the realization of a quantum system with at least one hundred dimensions, formed by two entangled qudits with D = 10. Furthermore, using state-of-the-art, yet off-the-shelf telecommunications components, we introduce a coherent manipulation platform with which to control frequency-entangled states, capable of performing deterministic high-dimensional gate operations. We validate this platform by measuring Bell inequality violations and performing quantum state tomography. Our work enables the generation and processing of high-dimensional quantum states in a single spatial mode.

  11. S-Mesh: a Mesh-based on-chip network with separation of control and transmission

    Institute of Scientific and Technical Information of China (English)

    LIU Hao; ZOU Xue-cheng; JI Li-xin; CAI Meng; ZHANG Ke-feng

    2009-01-01

    The current network-on-chip (NoC) topology cannot predict subsequent switch node status promptly. Switch nodes have to perform various functions such as routing decision, data forwarding, packet buffering, congestion control and properties of an NoC system. Therefore, these make switch architecture far more complex. This article puts forward a separating on-chip network architecture based on Mesh (S-Mesh). S-Mesh is an on-chip network that separates routing decision flow from the switches. It consists of two types of networks: datapath network (DN) and control network (CN). The CN establishes data paths for data transferring in DN. Meanwhile, the CN also transfers instructions between different resources. This property makes switch architecture simple, and eliminates conflicts in network interface units between the resource and switch. Compared with 2D-Mesh, Torus Mesh, Fat-tree and Butterfly, the average packet latency in S-Mesh is the shortest when the packet length is more than 53 B. Compared with 2D-Mesh, the areas savings of S-Mesh is about 3%--7%, and the power dissipation is decreased by approximate 2%.

  12. An innovative sample-to-answer polymer lab-on-a-chip with on-chip reservoirs for the POCT of thyroid stimulating hormone (TSH).

    Science.gov (United States)

    Jung, Wooseok; Han, Jungyoup; Kai, Junhai; Lim, Ji-Youn; Sul, Donggeun; Ahn, Chong H

    2013-12-07

    A new sample-to-answer polymer lab-on-a-chip, which can perform immunoassay with minimum user intervention through on-chip reservoirs for reagents and single-channel assay system, has been designed, developed and successfully characterized as a point-of-care testing (POCT) cartridge for the detection of thyroid stimulating hormone (TSH). Test results were obtained within 30 minutes after a sample was dropped into the POCT cartridge. The analyzed results of TSH showed a linear range of up to 55 μIU mL(-1) with the limit of detection (LOD) of 1.9 μIU mL(-1) at the signal-to-noise ratio (SNR) of 3. The reagents stored in the on-chip reservoirs maintained more than 97% of their initial volume for 120 days of storage time while the detection antibody retained its activity above 98% for 120 days. The sample-to-answer polymer lab-on-a-chip developed in this work using the mass-producible and low-cost polymer is well suited for the point-of-care testing of rapid in vitro diagnostics (IVD) of TSH.

  13. Preprogrammed, parallel on-chip immunoassay using system-level capillarity control.

    Science.gov (United States)

    Kim, Sung-Jin; Paczesny, Sophie; Takayama, Shuichi; Kurabayashi, Katsuo

    2013-07-16

    Fully manual use of conventional multiwell plates makes enzyme-linked immunosorbent assay (ELISA)-based immunoassays highly time-consuming and labor-intensive. Here, we present a capillarity-driven on-chip immunoassay that greatly saves time and labor with an inexpensive setup. Our immunoassay process starts with pipetting multiple solutions into multiwells constructed on a microfluidic device chip. Subsequently, capillarity spontaneously transports multiple sample solutions and common reagent solutions into assigned detection channels on the chip in a purely passive and preprogrammed manner. Our device implements capillarity-driven immunoassays involving four sample and six reagent solutions within 30 min by orchestrating the functions of on-chip passive components. Notably, our immunoassay technique reduces the total number of pipetting processes by ~5 times, as compared to assays on multiwell plates (48 vs 10). This assay technique allows us to quantify the concentrations of C-reactive protein and suppressor of tumorigenicity 2 with a detection limit of 8 and 90 pM, respectively. This device should be useful for sophisticated, parallel biochemical microfluidic processing in point-of-care settings under limited resources.

  14. Tunable on chip optofluidic laser

    DEFF Research Database (Denmark)

    Bakal, Avraham; Vannahme, Christoph; Kristensen, Anders

    2016-01-01

    On chip tunable laser is demonstrated by realizing a microfluidic droplet array. The periodicity is controlled by the pressure applied to two separate inlets, allowing to tune the lasing frequency over a broad spectral range.......On chip tunable laser is demonstrated by realizing a microfluidic droplet array. The periodicity is controlled by the pressure applied to two separate inlets, allowing to tune the lasing frequency over a broad spectral range....

  15. Magnetic actuator for the control and mixing of magnetic bead-based reactions on-chip.

    Science.gov (United States)

    Berenguel-Alonso, Miguel; Granados, Xavier; Faraudo, Jordi; Alonso-Chamarro, Julián; Puyol, Mar

    2014-10-01

    While magnetic bead (MB)-based bioassays have been implemented in integrated devices, their handling on-chip is normally either not optimal--i.e. only trapping is achieved, with aggregation of the beads--or requires complex actuator systems. Herein, we describe a simple and low-cost magnetic actuator to trap and move MBs within a microfluidic chamber in order to enhance the mixing of a MB-based reaction. The magnetic actuator consists of a CD-shaped plastic unit with an arrangement of embedded magnets which, when rotating, generate the mixing. The magnetic actuator has been used to enhance the amplification reaction of an enzyme-linked fluorescence immunoassay to detect Escherichia coli O157:H7 whole cells, an enterohemorrhagic strain, which have caused several outbreaks in food and water samples. A 2.7-fold sensitivity enhancement was attained with a detection limit of 603 colony-forming units (CFU) /mL, when employing the magnetic actuator.

  16. All-electronic droplet generation on-chip with real-time feedback control for EWOD digital microfluidics.

    Science.gov (United States)

    Gong, Jian; Kim, Chang-Jin C J

    2008-06-01

    Electrowetting-on-dielectric (EWOD) actuation enables digital (or droplet) microfluidics where small packets of liquids are manipulated on a two-dimensional surface. Due to its mechanical simplicity and low energy consumption, EWOD holds particular promise for portable systems. To improve volume precision of the droplets, which is desired for quantitative applications such as biochemical assays, existing practices would require near-perfect device fabrication and operation conditions unless the droplets are generated under feedback control by an extra pump setup off of the chip. In this paper, we develop an all-electronic (i.e., no ancillary pumping) real-time feedback control of on-chip droplet generation. A fast voltage modulation, capacitance sensing, and discrete-time PID feedback controller are integrated on the operating electronic board. A significant improvement is obtained in the droplet volume uniformity, compared with an open loop control as well as the previous feedback control employing an external pump. Furthermore, this new capability empowers users to prescribe the droplet volume even below the previously considered minimum, allowing, for example, 1 : x (x < 1) mixing, in comparison to the previously considered n : m mixing (i.e., n and m unit droplets).

  17. ALL-ELECTRONIC DROPLET GENERATION ON-CHIP WITH REAL-TIME FEEDBACK CONTROL FOR EWOD DIGITIAL MICROFLUIDICS

    Science.gov (United States)

    Gong, Jian; Kim, Chang-Jin “CJ”

    2009-01-01

    Electrowetting-on-dielectric (EWOD) actuation enables digital (or droplet) microfluidics where small packets of liquids are manipulated on a two-dimensional surface. Due to its mechanical simplicity and low energy consumption, EWOD holds particular promise for portable systems. To improve volume precision of the droplets, which is desired for quantitative applications such as biochemical assays, existing practices would require near-perfect device fabricaion and operation conditions unless the droplets are generated under feedback control by an extra pump setup off of the chip. In this paper, we develop an all-electronic (i.e., no ancillary pumping) real-time feedback control of on-chip droplet generation. A fast voltage modulation, capacitance sensing, and discrete-time PID feedback controller are integrated on the operating electronic board. A significant improvement is obtained in the droplet volume uniformity, compared with an open loop control as well as the previous feedback control employing an external pump. Furthermore, this new capability empowers users to prescribe the droplet volume even below the previously considered minimum, allowing, for example, 1:x (x < 1) mixing, in comparison to the previously considered n:m mixing (i.e., n and m unit droplets). PMID:18497909

  18. Programmable System on Chip Distributed Communication and Control Approach for Human Adaptive Mechanical System

    Directory of Open Access Journals (Sweden)

    Ahmad A.M. Faudzi

    2010-01-01

    Full Text Available Problem statement: Communication and control are two main components in any Mechatronics system. They can be designed either by centralized or decentralized approach. Both approaches can be chosen based on application designed and specific requirements of the designer. In this study, decentralized or normally called distributed approach was selected to solved communication and control of a human adaptive mechanical system namely Intelligent Chair Tools (ICT. The ICT seating system is powered by thirty six intelligent pneumatic actuators to facilitate investigation of chair shapes from spring and damping effect of seating and backrest surface. Three studies are proposed from the sitting experiments namely chair shapes, chair spring and chair damping properties. Approach: PSoC microcontroller was selected based on its features of having configurable analog and digital blocks. Its flexible modules and programmable peripherals ease designer in designing the communication and control of ICT in improved and faster way. Three protocols of USB, SPI and I2C were used for the communication system of ICT using PSoC. Flow charts of each communication protocols algorithms were discussed. On the other hand, the control system used PSoC’s ADC and counter modules to read inputs of pressure and encoder respectively. PWM module is used to control the valve and data communication was achieved using I2C module. Block diagram of unified control was discussed for further understandings of the control algorithms. Results: The PSoC specification, development design and experimental evaluation of ICT system are presented and discussed. Three studies of chair shapes, chair spring property and chair damping property from sitting experiment were shown. Conclusion/Recommendations: The PSoC microcontroller selection was discussed and application of its distributed communication and control was successfully applied to ICT. This distributed approach can be applied to other

  19. Programmable System on Chip Distributed Communication and Control Approach for Human Adaptive Mechanical System

    OpenAIRE

    Ahmad A.M. Faudzi; Suzumori, K

    2010-01-01

    Problem statement: Communication and control are two main components in any Mechatronics system. They can be designed either by centralized or decentralized approach. Both approaches can be chosen based on application designed and specific requirements of the designer. In this study, decentralized or normally called distributed approach was selected to solved communication and control of a human adaptive mechanical system namely Intelligent Chair Tools (ICT). The ICT seating system is powered...

  20. Integrated S-band transmitter with on-chip DC-DC converter and control loop

    NARCIS (Netherlands)

    Brouzes, H.; Geurts, S.; Besselink, M.; Telli, A.; Hek, A.P. de; Bent, G. van der; Vliet, F.E. van

    2012-01-01

    A highly integrated high-power transmitter has been designed in a high breakdown GaAs MMIC technology. The transmitter includes, on top of an S-Band 10 W class-F HPA, a DC/DC converter and its associated gate driver, the full voltage regulation control loop, which provides a significant step for pha

  1. Integrated Microfluidic Membrane Transistor Utilizing Chemical Information for On-Chip Flow Control.

    Science.gov (United States)

    Frank, Philipp; Schreiter, Joerg; Haefner, Sebastian; Paschew, Georgi; Voigt, Andreas; Richter, Andreas

    2016-01-01

    Microfluidics is a great enabling technology for biology, biotechnology, chemistry and general life sciences. Despite many promising predictions of its progress, microfluidics has not reached its full potential yet. To unleash this potential, we propose the use of intrinsically active hydrogels, which work as sensors and actuators at the same time, in microfluidic channel networks. These materials transfer a chemical input signal such as a substance concentration into a mechanical output. This way chemical information is processed and analyzed on the spot without the need for an external control unit. Inspired by the development electronics, our approach focuses on the development of single transistor-like components, which have the potential to be used in an integrated circuit technology. Here, we present membrane isolated chemical volume phase transition transistor (MIS-CVPT). The device is characterized in terms of the flow rate from source to drain, depending on the chemical concentration in the control channel, the source-drain pressure drop and the operating temperature.

  2. Control of coherent information via on chip photonic-phononic emitter-receivers

    CERN Document Server

    Shin, Heedeuk; Jarecki, Robert; Starbuck, Andrew; Wang, Zheng; Rakich, Peter T

    2014-01-01

    Rapid progress in silicon photonics has fostered numerous chip-scale sensing, computing, and signal processing technologies. However, many crucial filtering and signal delay operations are difficult to perform with all-optical devices. Unlike photons propagating at luminal speeds, GHz-acoustic phonons with slow velocity allow information to be stored, filtered, and delayed over comparatively smaller length-scales with remarkable fidelity. Hence, controllable and efficient coupling between coherent photons and phonons enables new signal processing technologies that greatly enhance the performance and potential impact of silicon photonics. Here, we demonstrate a novel mechanism for coherent information processing based on traveling-wave photon-phonon transduction, which achieves a phonon emit-and-receive process between distinct nanophotonic waveguides. Using this device physics-which can support 1-20GHz frequencies-we create wavelength-insensitive radio-frequency photonic filters with an unrivaled combination ...

  3. Reconfigurable Networks-on-Chip

    CERN Document Server

    Chen, Sao-Jie; Tsai, Wen-Chung; Hu, Yu-Hen

    2012-01-01

    This book provides a comprehensive survey of recent progress in the design and implementation of Networks-on-Chip. It addresses a wide spectrum of on-chip communication problems, ranging from physical, network, to application layers. Specific topics that are explored in detail include packet routing, resource arbitration, error control/correction, application mapping, and communication scheduling. Additionally, a novel bi-directional communication channel NoC (BiNoC) architecture is described, with detailed explanation.   Written for practicing engineers in need of practical knowledge about the design and implementation of networks-on-chip; Includes tutorial-like details to introduce readers to a diverse range of NoC designs, as well as in-depth analysis for designers with NoC experience to explore advanced issues; Describes a variety of on-chip communication architectures, including a novel bi-directional communication channel NoC.     From the Foreword: Overall this book shows important advances over the...

  4. Density controlled nanophotonic waveguide gratings for efficient on-chip out-coupling in the near field (Conference Presentation)

    Science.gov (United States)

    Vercruysse, Dries; Mukund, Vignesh; Jansen, Roelof; Stahl, Richard; Van Dorpe, Pol; Lagae, Liesbet; Rottenberg, Xavier

    2016-05-01

    these gratings can couple out more complex holographic patterns. These density controlled out-coupling gratings let us efficiently address the near-field on optical chips, making them ideal waveguide components for on-chip optical trapping, holographic imaging or fluorescent excitation.[3

  5. Microcontroller based closed-loop control of a 2D quasi-static/resonant microscanner with on-chip piezo-resistive sensor feedback

    Science.gov (United States)

    Schroedter, Richard; Schwarzenberg, Markus; Dreyhaupt, André; Barth, Robert; Sandner, Thilo; Janschek, Klaus

    2017-02-01

    In this paper we present a 2D raster scanning quasi-static/resonant micro mirror being controlled in both axes in closed-loop with on-chip piezo-resistive sensor feedback. While the resonant axis oscillates with a given frequency, the quasi-static axis allows static as well as dynamic deflection up to its eigenfrequency because of its staggered vertical comb (SVC) drive arrangement. Due to the high quality factor of the very low damped spring-masssystem, an adapted trajectory planning using jerk limitation is applied for the quasi-static axis [1]. Nevertheless, inaccuracies of the applied nonlinear micro mirror model and external disturbances lead to undesired residual oscillation in open-loop control mode. To achieve high precise and fast beam positioning, we implement a flatness-based control algorithm with feedback to on-chip piezo-resistive deflection sensors. In comparison to previous work [2, 3], we developed a micro controller setup for driving the microscanner, that is equipped with an analog Bessel filter increasing the sensor signal quality significantly. In this study we demonstrate a small size and low power micro mirror driver including high-voltage generation and a microcontroller for real-time control as well as a head circuit board for high resolution sensing. We discuss experimental results of open-loop and closed-loop control for 2D raster scanning operation. Finally, the outlook is given to the intrinsic capability to compensate temperature drifts influencing the piezo-resistive sensor signal.

  6. On-chip plasmonic spectrometer.

    Science.gov (United States)

    Tsur, Yuval; Arie, Ady

    2016-08-01

    We report a numerical and experimental study of an on-chip optical spectrometer, utilizing propagating surface plasmon polaritons in the telecom spectral range. The device is based on two holographic gratings, one for coupling, and the other for decoupling free-space radiation with the surface plasmons. This 800 μm×100 μm on-chip spectrometer resolves 17 channels spectrally separated by 3.1 nm, spanning a freely tunable spectral window, and is based on standard lithography fabrication technology. We propose two potential applications for this new device; the first employs the holographic control over the amplitude and phase of the input spectrum, for intrinsically filtering unwanted frequencies, like pump radiation in Raman spectroscopy. The second prospect utilizes the unique plasmonic field enhancement at the metal-dielectric boundary for the spectral analysis of very small samples (e.g., Mie scatterers) placed between the two gratings.

  7. On-chip frequency compensation with a dual signal path operational transconductance amplifier for a voltage mode control DC/DC converter

    Science.gov (United States)

    Qiang, Ye; Jie, Liu; Bing, Yuan; Xinquan, Lai; Ning, Liu

    2012-04-01

    A novel on-chip frequency compensation circuit for a voltage-mode control DC/DC converter is presented. By employing an RC network in the two signal paths of an operational transconductance amplifier (OTA), the proposed circuit generates two zeros to realize high closed-loop stability. Meanwhile, full on-chip integration is also achieved due to its simple structure. Hence, the number of off-chip components and the board space is greatly reduced. The structure of the dual signal path OTA is also optimized to help get a better transition response. Implemented in a 0.5 μm CMOS process, the voltage mode control DC/DC converter with the proposed frequency compensation circuit exhibits good stability. The test results show that both load and line regulations are less than 0.3%, and the output voltage can be recovered within 15 μs for a 400 mA load step. Moreover, the compensation components area is less than 2% of the die's area and the board space is also reduced by 11%. The efficiency of the whole chip can be up to 95%.

  8. Development and applications of a multi-purpose digital controller with a System-on-Chip FPGA for accelerators

    Science.gov (United States)

    Kurimoto, Yoshinori; Nakamura, Keigo

    2016-12-01

    J-PARC Main Ring (MR) is a high intensity proton synchrotron which accelerates protons from 3 GeV to 30 GeV. It has operated at a beam intensity of 390 kW and an upgrade toward the megawatt rating is scheduled. For higher beam intensity, some of the accelerator components require more intelligent and complicated functions. To consolidate such functions among various components, we developed multi-purpose digital boards using a System-on-Chip Field-Programmable Gated Array (SoC FPGA). In this paper, we describe the details of our developed boards as well as their possible applications. As an application of the boards, we have successfully performed the measurement of the betatron amplitude function during beam acceleration in J-PARC MR. The experimental setup and results of the measurement are also described in detail.

  9. Microfluidic on chip viscometers.

    Science.gov (United States)

    Chevalier, J; Ayela, F

    2008-07-01

    We present the design and the process of fabrication of micromachined capillary on chip rheometers which have performed wall shear stress and shear rate measurements on silicon oil and ethanol-based nanofluids. The originality of these devices comes from the fact that local pressure drop measurements are performed inside the microchannels. Thus, the advantage over existing microviscometers is that they can be used with the fluid under test alone; no reference fluid nor posttreatment of the data are needed. Each on chip viscometer consists of anodically bonded silicon-Pyrex derivative microchannels equipped with local probes. The anodic bonding allows to reach relatively high pressure levels (up to approximately 10 bars) in the channels, and a broad range of shear stress and shear rate values is attainable. Dielectrophoretic and electrorheological effects can be highlighted by employing alternate microstripe electrodes patterned onto the inner side of the Pyrex wall.

  10. Stimulants for the control of hedonic appetite

    Directory of Open Access Journals (Sweden)

    Alison Sally Poulton

    2016-04-01

    Full Text Available The focus of this paper is treatment of obesity in relation to the management of hedonic appetite. Obesity is a complex condition which may be potentiated by excessive reward seeking in combination with executive functioning deficits that impair cognitive control of behaviour. Stimulant medications address both reward deficiency and enhance motivation, as well as suppressing appetite. They have long been recognised to be effective for treating obesity. However, stimulants can be abused for their euphoric effect. They induce euphoria via the same neural pathway that underlies their therapeutic effect in obesity. For this reason they have generally not been endorsed for use in obesity. Among the stimulants, only phentermine (either alone or in combination with topiramate and bupropion (which has stimulant-like properties and is used in combination with naltrexone, are approved by the United States Food and Drug Administration (FDA for obesity, although dexamphetamine and methylpenidate are approved and widely used for treating attention deficit hyperactivity disorder (ADHD in adults and children. Experience gained over many years in the treatment of ADHD demonstrates that with careful dose titration, stimulants can be used safely. In obesity, improvement in mood and executive functioning could assist with the lifestyle changes necessary for weight control, acting synergistically with appetite suppression. The obesity crisis has reached the stage that strong consideration should be given to adequate utilisation of this effective and inexpensive class of drug.

  11. Heart rate control via vagus nerve stimulation

    NARCIS (Netherlands)

    Buschman, Hendrik P.; Storm, Corstiaan J.; Duncker, Dirk J.; Verdouw, Pieter D.; Aa, van der Hans E.; Kemp, van der Peter

    2006-01-01

    Objectives: There is ample and well-established evidence that direct electrical stimulation of the vagus nerve can change heart rate in animals and humans. Since tachyarrhythmias cannot always be controlled through medication, we sought, in this pilot study, to elucidate whether a clinical implantab

  12. An energy-efficient Network-on-Chip for a heterogeneous tiled reconfigurable System-on-Chip

    NARCIS (Netherlands)

    Kavaldjiev, N.K.; Smit, Gerardus Johannes Maria

    This paper proposes a Network-on-Chip architecture that offers high flexibility and performance. It is used in a System-on-Chip platform for future multimedia mobile devices. The network is packet switching wormhole network with virtual-channel flow control and source routing. The initial

  13. An energy-efficient Network-on-Chip for a heterogeneous tiled reconfigurable Systems-on-Chip

    NARCIS (Netherlands)

    Kavaldjiev, N.K.; Smit, Gerardus Johannes Maria

    This paper proposes a Network-on-Chip architecture that offers high flexibility and performance. It is used in a System-on-Chip platform for future multimedia mobile devices. The network is packet switching wormhole network with virtual-channel flow control and source routing. The initial

  14. Measurement and Management of the Level of Quality Control Process in SoC (System on Chip Embedded Software Development

    Directory of Open Access Journals (Sweden)

    Ki-won Song

    2012-04-01

    quality control activities and it is desirable to create a quality process to integrally represent overall level of quality control activities performed while developing the software deliverables. With the quality process, it is possible to evaluate whether enough quality control activities are performed for the project officially and secure the quality of the software deliverables before it is delivered to the customers.

  15. Note: Guaranteed collocated multimode control of an atomic force microscope cantilever using on-chip piezoelectric actuation and sensing

    Science.gov (United States)

    Ruppert, Michael G.; Yong, Yuen K.

    2017-08-01

    The quality (Q) factor is an important parameter of the resonance of the microcantilever as it determines both imaging bandwidth and force sensitivity. The ability to control the Q factor of multiple modes is believed to be of great benefit for atomic force microscopy techniques involving multiple eigenmodes. In this paper, we propose a novel cantilever design employing multiple piezoelectric transducers which are used for separated actuation and sensing, leading to guaranteed collocation of the first eight eigenmodes up to 3 MHz. The design minimizes the feedthrough usually observed with these systems by incorporating a guard trace on the cantilever chip. As a result, a multimode Q controller is demonstrated to be able to modify the quality factor of the first two eigenmodes over up to four orders of magnitude without sacrificing robust stability.

  16. Automated, Miniaturized and Integrated Quality Control-on-Chip (QC-on-a-Chip for Advanced Cell Therapy Applications

    Directory of Open Access Journals (Sweden)

    David eWartmann

    2015-09-01

    Full Text Available The combination of microfabrication-based technologies with cell biology has laid the foundation for the development of advanced in vitro diagnostic systems capable of evaluating cell cultures under defined, reproducible and standardizable measurement conditions. In the present review we describe recent lab-on-a-chip developments for cell analysis and how these methodologies could improve standard quality control in the field of manufacturing cell-based vaccines for clinical purposes. We highlight in particular the regulatory requirements for advanced cell therapy applications using as an example dendritic cell-based cancer vaccines to describe the tangible advantages of microfluidic devices that overcome most of the challenges associated with automation, miniaturization and integration of cell-based assays. As its main advantage lab-on-a-chip technology allows for precise regulation of culturing conditions, while simultaneously monitoring cell relevant parameters using embedded sensory systems. State-of-the-art lab-on-a-chip platforms for in vitro assessment of cell cultures and their potential future applications for cell therapies and cancer immunotherapy are discussed in the present review.

  17. Automated, Miniaturized and Integrated Quality Control-on-Chip (QC-on-a-Chip) for Advanced Cell Therapy Applications

    Science.gov (United States)

    Wartmann, David; Rothbauer, Mario; Kuten, Olga; Barresi, Caterina; Visus, Carmen; Felzmann, Thomas; Ertl, Peter

    2015-09-01

    The combination of microfabrication-based technologies with cell biology has laid the foundation for the development of advanced in vitro diagnostic systems capable of evaluating cell cultures under defined, reproducible and standardizable measurement conditions. In the present review we describe recent lab-on-a-chip developments for cell analysis and how these methodologies could improve standard quality control in the field of manufacturing cell-based vaccines for clinical purposes. We highlight in particular the regulatory requirements for advanced cell therapy applications using as an example dendritic cell-based cancer vaccines to describe the tangible advantages of microfluidic devices that overcome most of the challenges associated with automation, miniaturization and integration of cell-based assays. As its main advantage lab-on-a-chip technology allows for precise regulation of culturing conditions, while simultaneously monitoring cell relevant parameters using embedded sensory systems. State-of-the-art lab-on-a-chip platforms for in vitro assessment of cell cultures and their potential future applications for cell therapies and cancer immunotherapy are discussed in the present review.

  18. Fine temporal control of the medium gas content and acidity and on-chip generation of series of oxygen concentrations for cell cultures.

    Science.gov (United States)

    Polinkovsky, Mark; Gutierrez, Edgar; Levchenko, Andre; Groisman, Alex

    2009-04-21

    We describe the design, operation, and applications of two microfluidic devices that generate series of concentrations of oxygen, [O(2)], by on-chip gas mixing. Both devices are made of polydimethylsiloxane (PDMS) and have two layers of channels, the flow layer and the gas layer. By using in-situ measurements of [O(2)] with an oxygen-sensitive fluorescent dye, we show that gas diffusion through PDMS leads to equilibration of [O(2)] in an aqueous solution in the flow layer with [O(2)] in a gas injected into the gas layer on a time scale of approximately 1 sec. Injection of carbon dioxide into the gas layer causes the pH in the flow layer to drop within approximately 0.5 sec. Gas-mixing channel networks of both devices generate series of 9 gas mixtures with different [O(2)] from two gases fed to the inlets, thus creating regions with 9 different [O(2)] in the flow layer. The first device generates nitrogen-oxygen mixtures with [O(2)] varying linearly between 0 and 100%. The second device generates nitrogen-air mixtures with [O(2)] varying exponentially between 0 and 20.9%. The flow layers of the devices are designed for culturing bacteria in semi-permeable microchambers, and the second device is used to measure growth curves of E. coli colonies at 9 different [O(2)] in a single experiment. The cell division rates at [O(2)] of 0, 0.2, and 0.5% are found to be significantly different, further validating the capacity of the device to set [O(2)] in the flow layer with high precision and resolution. The degree of control of [O(2)] achieved in the devices and the robustness with respect to oxygen consumption due to respiration would be difficult to match in a traditional large-scale culture. The proposed devices and technology can be used in research on bacteria and yeast under microaerobic conditions and on mammalian cells under hypoxia.

  19. On-chip data communication

    NARCIS (Netherlands)

    Schinkel, Daniel

    2011-01-01

    On-chip data communication is an active research area, as interconnects are rapidly becoming a speed, power and reliability bottleneck for digital CMOS systems. Especially for global interconnects that have to span large parts of a chip, there is an increasing gap between transistor speed and interc

  20. On-chip data communication

    NARCIS (Netherlands)

    Schinkel, Daniel

    2011-01-01

    On-chip data communication is an active research area, as interconnects are rapidly becoming a speed, power and reliability bottleneck for digital CMOS systems. Especially for global interconnects that have to span large parts of a chip, there is an increasing gap between transistor speed and

  1. Computer-controlled stimulator for clinical cardiac studies

    NARCIS (Netherlands)

    Heethaar, R.M.; Poelgeest, R. van; Meijler, F.L.; Woudstra, E.S.; Zouw, C. van de

    A computer-controlled stimulator is described to generate the complex stimulation patterns required for a detailed analysis of ventricular myocardial function and the responses of the conduction system to applied stimuli, Pulse interval, height and width can be generated on a beat-to-beat basis.

  2. Computer-controlled stimulator for clinical cardiac studies

    NARCIS (Netherlands)

    Heethaar, R.M.; Poelgeest, R. van; Meijler, F.L.; Woudstra, E.S.; Zouw, C. van de

    1977-01-01

    A computer-controlled stimulator is described to generate the complex stimulation patterns required for a detailed analysis of ventricular myocardial function and the responses of the conduction system to applied stimuli, Pulse interval, height and width can be generated on a beat-to-beat basis. For

  3. Ion chromatography on-chip.

    Science.gov (United States)

    Murrihy, J P; Breadmore, M C; Tan, A; McEnery, M; Alderman, J; O'Mathuna, C; O'Neill, A P; O'Brien, P; Avdalovic, N; Haddad, P R; Glennon, J D; Advoldvic, N

    2001-07-27

    On-chip separation of inorganic anions by ion-exchange chromatography was realized. Micro separation channels were fabricated on a silicon wafer and sealed with a Pyrex cover plate using standard photolithography, wet and dry chemical etching, and anodic bonding techniques. Quaternary ammonium latex particles were employed for the first time to coat the separation channels on-chip. Owing to the narrow depths of the channels on the chip, 0.5-10 microm, there were more interactions of the analytes with the stationary phase on the chip than in a 50-microm I.D. capillary. With off-chip injection (20 nl) and UV detection, NO2-, NO3-, I-, and thiourea were separated using 1 mM KCl as the eluent. The linear ranges for NO2- and NO3- are from 5 to 1000 microM with the detection limits of 0.5 microM.

  4. Impact of behavioral control on the processing of nociceptive stimulation

    Directory of Open Access Journals (Sweden)

    James W Grau

    2012-08-01

    Full Text Available How nociceptive signals are processed within the spinal cord, and whether these signals lead to behavioral signs of neuropathic pain, depends upon their relation to other events and behavior. Our work shows that these relations can have a lasting effect on spinal plasticity, inducing a form of learning that alters the effect of subsequent nociceptive stimuli. The capacity of lower spinal systems to adapt, in the absence of brain input, is examined in spinally transected rats that receive a nociceptive shock to the tibialis anterior muscle of one hind leg. If shock is delivered whenever the leg is extended (controllable stimulation, it induces an increase in flexion duration that minimizes net shock exposure. This learning is not observed in subjects that receive the same amount of shock independent of leg position (uncontrollable stimulation. These two forms of stimulation have a lasting, and divergent, effect on subsequent learning: Controllable stimulation enables learning whereas uncontrollable stimulation disables it (learning deficit. Uncontrollable stimulation also enhances mechanical reactivity (allodynia. We review evidence that training with controllable stimulation engages a BDNF-dependent process that can both prevent and reverse the consequences of uncontrollable shock. We relate these effects to changes in BDNF protein and TrkB signaling. Controllable stimulation is also shown to counter the effects of peripheral inflammation (from intradermal capsaicin. A model is proposed that assumes nociceptive input is gated at an early stage, within the dorsal horn. his gate is sensitive to current environmental relations (between proprioceptive and nociceptive input, allowing stimulation to be classified as controllable or uncontrollable. We further propose that the status of this gate is affected by past experience and that a history of uncontrollable stimulation will promote the development of neuropathic pain.

  5. Nanoparticle Reactions on Chip

    Science.gov (United States)

    Köhler, J. M.; Kirner, Th.; Wagner, J.; Csáki, A.; Möller, R.; Fritzsche, W.

    The handling of heterogenous systems in micro reactors is difficult due to their adhesion and transport behaviour. Therefore, the formation of precipitates and gas bubbles has to be avoided in micro reaction technology, in most cases. But, micro channels and other micro reactors offer interesting possibilities for the control of reaction conditions and transport by diffusion and convection due to the laminar flow caused by small Reynolds numbers. This can be used for the preparation and modification of objects, which are much smaller than the cross section of microchannels. The formation of colloidal solutions and the change of surface states of nano particles are two important tasks for the application of chip reactors in nanoparticle technology. Some concepts for the preparation and reaction of nanoparticles in modular chip reactor arrangements will be discussed.

  6. Theory of feedback controlled brain stimulations for Parkinson's disease

    Science.gov (United States)

    Sanzeni, A.; Celani, A.; Tiana, G.; Vergassola, M.

    2016-01-01

    Limb tremor and other debilitating symptoms caused by the neurodegenerative Parkinson's disease are currently treated by administering drugs and by fixed-frequency deep brain stimulation. The latter interferes directly with the brain dynamics by delivering electrical impulses to neurons in the subthalamic nucleus. While deep brain stimulation has shown therapeutic benefits in many instances, its mechanism is still unclear. Since its understanding could lead to improved protocols of stimulation and feedback control, we have studied a mathematical model of the many-body neural network dynamics controlling the dynamics of the basal ganglia. On the basis of the results obtained from the model, we propose a new procedure of active stimulation, that depends on the feedback of the network and that respects the constraints imposed by existing technology. We show by numerical simulations that the new protocol outperforms the standard ones for deep brain stimulation and we suggest future experiments that could further improve the feedback procedure.

  7. Fuzzy Control Method with Application for Functional Neuromuscular Stimulation System

    Institute of Scientific and Technical Information of China (English)

    吴怀宇; 周兆英; 熊沈蜀

    2001-01-01

    A fuzzy control technique is applied to a functional neuromuscular stimulation (FNS) physicalmultiarticular muscle control system. The FNS multiarticular muscle control system based on the fuzzy controllerwas developed with the fuzzy control rule base. Simulation experiments were then conducted for the joint angletrajectories of both the elbow flexion and the wrist flexion using the proposed fuzzy control algorithm and aconventional PID control algorithm with the FNS physical multiarticular muscle control system. The simulationresults demonstrated that the proposed fuzzy control method is more suitable for the physiologicalcharacteristics than conventional PID control. In particular, both the trajectory-following and the stability of theFNS multiarticular muscle control system were greatly improved. Furthermore, the stimulating pulse trainsgenerated by the fuzzy controller were stable and smooth.``

  8. Exploration within the Network-on-Chip Paradigm

    NARCIS (Netherlands)

    Wolkotte, Pascal Theodoor

    2009-01-01

    A general purpose processor used to consist of a single processing core, which performed and controlled all tasks on the chip. Its functionality and maximum clock frequency grew steadily over the years. Due to the continuous increase of the number of transistors available on-chip and the operational

  9. Reverse Engineering Human Pathophysiology with Organs-on-Chips.

    Science.gov (United States)

    Ingber, Donald E

    2016-03-10

    While studies of cultured cells have led to new insights into biological control, greater understanding of human pathophysiology requires the development of experimental systems that permit analysis of intercellular communications and tissue-tissue interactions in a more relevant organ context. Human organs-on-chips offer a potentially powerful new approach to confront this long-standing problem.

  10. Exploration within the Network-on-Chip Paradigm

    NARCIS (Netherlands)

    Wolkotte, P.T.

    2009-01-01

    A general purpose processor used to consist of a single processing core, which performed and controlled all tasks on the chip. Its functionality and maximum clock frequency grew steadily over the years. Due to the continuous increase of the number of transistors available on-chip and the operational

  11. On-Chip Detection of Cellular Activity

    Science.gov (United States)

    Almog, R.; Daniel, R.; Vernick, S.; Ron, A.; Ben-Yoav, H.; Shacham-Diamand, Y.

    The use of on-chip cellular activity monitoring for biological/chemical sensing is promising for environmental, medical and pharmaceutical applications. The miniaturization revolution in microelectronics is harnessed to provide on-chip detection of cellular activity, opening new horizons for miniature, fast, low cost and portable screening and monitoring devices. In this chapter we survey different on-chip cellular activity detection technologies based on electrochemical, bio-impedance and optical detection. Both prokaryotic and eukaryotic cell-on-chip technologies are mentioned and reviewed.

  12. Physiologically relevant organs on chips.

    Science.gov (United States)

    Yum, Kyungsuk; Hong, Soon Gweon; Healy, Kevin E; Lee, Luke P

    2014-01-01

    Recent advances in integrating microengineering and tissue engineering have generated promising microengineered physiological models for experimental medicine and pharmaceutical research. Here we review the recent development of microengineered physiological systems, or also known as "ogans-on-chips", that reconstitute the physiologically critical features of specific human tissues and organs and their interactions. This technology uses microengineering approaches to construct organ-specific microenvironments, reconstituting tissue structures, tissue-tissue interactions and interfaces, and dynamic mechanical and biochemical stimuli found in specific organs, to direct cells to assemble into functional tissues. We first discuss microengineering approaches to reproduce the key elements of physiologically important, dynamic mechanical microenvironments, biochemical microenvironments, and microarchitectures of specific tissues and organs in microfluidic cell culture systems. This is followed by examples of microengineered individual organ models that incorporate the key elements of physiological microenvironments into single microfluidic cell culture systems to reproduce organ-level functions. Finally, microengineered multiple organ systems that simulate multiple organ interactions to better represent human physiology, including human responses to drugs, is covered in this review. This emerging organs-on-chips technology has the potential to become an alternative to 2D and 3D cell culture and animal models for experimental medicine, human disease modeling, drug development, and toxicology.

  13. Remote controlled bio-stimulator and animal behavior analysis system

    Science.gov (United States)

    Song, Weiguo; Yuan, Kui; Han, Taizhen; Chai, Jie

    2006-01-01

    This paper presents a surveillance and stimulation system to study the animal locomotion behavior under electrical micro-stimulations in the brain nerve, which provides a new platform and methodology for behavior experiment in neural science. The system consists of two parts: 1) micro-control based multi-channel stimulator backed by animal; 2) Computer vision based animal behavior tracking system; The performance of the micro-stimulator is validated for sciatic nerve of frog and the results show that it is reliable, stabile, compact (25×35×10 mm), light (20g with cell). The tracking speed and accuracy is improved with our new hybrid tracking algorithm based on color table looking and moving predication, and compared with the manual recording. The preliminary results of rat tracking show that it works accurately and robustly in real-time even under interference condition.

  14. Asynchronous design of Networks-on-Chip

    DEFF Research Database (Denmark)

    Sparsø, Jens

    2007-01-01

    The Network-on-chip concept has evolved as a solution to a broad range of problems related to the design of complex systems-on-chip (SoC) with tenths or hundreds of (heterogeneous) IP-cores. The paper introduces the NoC concept, identifies a range of possible timing organizations (globally...

  15. Towards Dependable Network-on-Chip Architectures

    NARCIS (Netherlands)

    Chen, C.

    2015-01-01

    The aggressive semiconductor technology scaling provides the means for doubling the amount of transistors on a single chip each and every 18 months. To efficiently utilize these vast chip resources, Multi-Processor Systems on Chip (MPSoCs) integrated with a Network-on-Chip (NoC) communication infras

  16. Computer Controlled Switching Device for Deep Brain Stimulation

    Directory of Open Access Journals (Sweden)

    J. Tauchmanová

    2007-01-01

    Full Text Available This paper has two goals. The practical part deals with the design of a computer controlled switching device for an external stimulator for deep brain stimulation. The switching device is used during investigations with functional magnetic resonance for controlling signals leading to the deep brain stimulation (DBS electrode in the patient's brain. The motivation for designing this device was improve measured data quality and to enable new types of experiments.The theoretical part reports on early attempts to approach the problem of modeling and localizing the neural response of the human brain as a system identification and estimation task. The parametric identification method and real fMRI data are used for modeling the hemodynamic response.The project is in cooperation with 1st Faculty of Medicine, Charles University in Prague and Na Homolce hospital in Prague.

  17. Cognitive Stimulation in Patients with Dementia: Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Daniela Mapelli

    2013-08-01

    Full Text Available Background/Aims: This study explores the effective outcomes of a structured cognitive stimulation treatment to improve cognition and behavioral symptoms in people with dementia (PWDs, using a randomized controlled clinical trial. Methods: Thirty PWDs were divided into three groups: experimental (treated with cognitive stimulation, placebo (treated with occupational therapy, and control (continuing with the usual activities of the nursing home. Assessment, at baseline and after a period of 8 weeks, was performed using the Clinical Dementia Rating Scale, activities of daily living, Mini-Mental State Examination, Esame Neuropsicologico Breve 2, Geriatric Depression Scale and Behavioral Pathology in Alzheimer's Disease Scale. Results: Only the experimental group improved its performance in cognitive tests (p Conclusions: The results suggest that a cognitive stimulation treatment for PWDs would improve not only their cognition, but also behavioral symptoms.

  18. Remote control of microcontroller-based infant stimulating system.

    Science.gov (United States)

    Burunkaya, M; Güler, I

    2000-04-01

    In this paper, a remote-controlled and microcontroller-based cradle is designed and constructed. This system is also called Remote Control of Microcontroller-Based Infant Stimulation System or the RECOMBIS System. Cradle is an infant stimulating system that provides relaxation and sleeping for the baby. RECOMBIS system is designed for healthy full-term newborns to provide safe infant care and provide relaxation and sleeping for the baby. A microcontroller-based electronic circuit was designed and implemented for RECOMBIS system. Electromagnets were controlled by 8-bit PIC16F84 microcontroller, which is programmed using MPASM package. The system works by entering preset values from the keyboard, or pulse code modulated radio frequency remote control system. The control of the system and the motion range were tested. The test results showed that the system provided a good performance.

  19. On-Chip Random Spectrometer

    CERN Document Server

    Redding, Brandon; Sarma, Raktim

    2013-01-01

    Light scattering in disordered media has been studied extensively due to its prevalence in natural and artificial systems [1]. In the field of photonics most of the research has focused on understanding and mitigating the effects of scattering, which are often detrimental. For certain applications, however, intentionally introducing disorder can actually improve the device performance, e.g., in photovoltaics optical scattering improves the efficiency of light harvesting [2-5]. Here, we utilize multiple scattering in a random photonic structure to build a compact on-chip spectrometer. The probe signal diffuses through a scattering medium generating wavelength-dependent speckle patterns which can be used to recover the input spectrum after calibration. Multiple scattering increases the optical pathlength by folding the paths in a confined geometry, enhancing the spectral decorrelation of speckle patterns and thus increasing the spectral resolution. By designing and fabricating the spectrometer on a silicon wafe...

  20. On-chip spiral spectrometer

    CERN Document Server

    Redding, Brandon; Bromberg, Yaron; Sarma, Raktim; Cao, Hui

    2016-01-01

    We designed an on-chip spectrometer based on an evanescently-coupled multimode spiral waveguide. Interference between the modes in the waveguide forms a wavelength-dependent speckle pattern which can be used as a fingerprint to identify the input wavelength after calibration. Evanescent coupling between neighboring arms of the spiral enhances the temporal spread of light propagating through the spiral, leading to a dramatic increase in the spectral resolution. Experimentally, we demonstrated that a 250 {\\mu}m radius spiral spectrometer provides a resolution of 0.01 nm at a wavelength of 1520 nm. Spectra containing 40 independent spectral channels can be recovered simultaneously and the operation bandwidth can be increased further when measuring sparse spectra.

  1. Socioeconomic evaluation of vagus stimulation: A controlled national study

    DEFF Research Database (Denmark)

    Jennum, Poul; Sabers, Anne; Christensen, Jakob

    2016-01-01

    PURPOSE: We aimed to determine the health costs and social outcomes in terms of education, employment and income level after insertion of a vagus nerve stimulator (VNS) in patients with epilepsy. METHODS: This is a case-control study using Danish health care and socioeconomic register data...

  2. Performance Analysis on Router Arbitration for On-chip Networking

    Directory of Open Access Journals (Sweden)

    G. Selvaraj

    2014-08-01

    Full Text Available This study is a comprehensive report on performance analyses of Round Robin and matrix arbitrations to enhance the reliability of on-chip networks. Arbiter is used in Network-on-Chip (NoC router when number of input ports requested is the same as output ports. If many inputs are requested for same output port, the matrix arbiter deals it by forming a 5×5 matrix based on input and output ports. Next, it allots the priority to the requested input ports and simultaneously generates a control signal for selecting the input port to send the packet to output port. The Robin arbiter generates the grant signal on the basis of priority allotted to the input ports. The simulation results of arbitration analysis shows that the router design of front end model consumes less power by 8% and occupies smaller area by 3% on chip. The area on chip is around 64% of available area using Round Robin arbitration compare to that of matrix arbitration. This study also implements hamming distance in order to check the error free data transmission of the NoC router.

  3. Controlling plasma stimulated media in cancer treatment application

    Science.gov (United States)

    Yan, Dayun; Sherman, Jonathan H.; Cheng, Xiaoqian; Ratovitski, Edward; Canady, Jerome; Keidar, Michael

    2014-12-01

    Cold atmospheric plasma (CAP) constitutes a "cocktail" of various reactive species. Accumulating evidence shows the effectiveness of CAP in killing cancer cells and decreasing the tumor size, which provides a solid basis for its potential use in cancer treatment. Currently, CAP is mainly used to directly treat cancer cells and trigger the death of cancer cells via apoptosis or necrosis. By altering the concentration of fetal bovine serum in Dulbecco's modified Eagle's medium and the temperature to store CAP stimulated media, we demonstrated controllable strategies to harness the stimulated media to kill glioblastoma cells in vitro. This study demonstrated the significant role of media in killing cancer cells via the CAP treatment.

  4. New algorithm to control a cycle ergometer using electrical stimulation.

    Science.gov (United States)

    Petrofsky, J S

    2003-01-01

    Data were collected from four male subjects to determine the relationships between load, speed and muscle use during cycle ergometry. These data were then used to construct equations to govern the stimulation of muscle in paralysed individuals, during cycle ergometry induced by functional electrical stimulation (FES) of the quadriceps, gluteus maximus and hamstring muscles. The algorithm was tested on four subjects who were paralysed owing to a complete spinal cord injury between T4 and T11. Using the multivariate equation, the control of movement was improved, and work was accomplished that was double (2940 Nm min(-1) compared with 5880 Nm min(-1)) that of traditional FES cycle ergometry, when muscle stimulation was also controlled by electrical stimulation. Stress on the body, assessed by cardiac output, was increased almost two-fold during maximum work with the new algorithm (81 min(-1) compared with 15 l min(-1) with the new algorithm). These data support the concept that the limitation to workload that a person can achieve on FES cycle ergometry is in the control equations and not in the paralysed muscle.

  5. Cytostretch, an Organ-on-Chip Platform

    Directory of Open Access Journals (Sweden)

    Nikolas Gaio

    2016-07-01

    Full Text Available Organ-on-Chips (OOCs are micro-fabricated devices which are used to culture cells in order to mimic functional units of human organs. The devices are designed to simulate the physiological environment of tissues in vivo. Cells in some types of OOCs can be stimulated in situ by electrical and/or mechanical actuators. These actuations can mimic physiological conditions in real tissue and may include fluid or air flow, or cyclic stretch and strain as they occur in the lung and heart. These conditions similarly affect cultured cells and may influence their ability to respond appropriately to physiological or pathological stimuli. To date, most focus has been on devices specifically designed to culture just one functional unit of a specific organ: lung alveoli, kidney nephrons or blood vessels, for example. In contrast, the modular Cytostretch membrane platform described here allows OOCs to be customized to different OOC applications. The platform utilizes silicon-based micro-fabrication techniques that allow low-cost, high-volume manufacturing. We describe the platform concept and its modules developed to date. Membrane variants include membranes with (i through-membrane pores that allow biological signaling molecules to pass between two different tissue compartments; (ii a stretchable micro-electrode array for electrical monitoring and stimulation; (iii micro-patterning to promote cell alignment; and (iv strain gauges to measure changes in substrate stress. This paper presents the fabrication and the proof of functionality for each module of the Cytostretch membrane. The assessment of each additional module demonstrate that a wide range of OOCs can be achieved.

  6. Photonic network-on-chip design

    CERN Document Server

    Bergman, Keren; Biberman, Aleksandr; Chan, Johnnie; Hendry, Gilbert

    2013-01-01

    This book provides a comprehensive synthesis of the theory and practice of photonic devices for networks-on-chip. It outlines the issues in designing photonic network-on-chip architectures for future many-core high performance chip multiprocessors. The discussion is built from the bottom up: starting with the design and implementation of key photonic devices and building blocks, reviewing networking and network-on-chip theory and existing research, and finishing with describing various architectures, their characteristics, and the impact they will have on a computing system. After acquainting

  7. Postural control responses sitting on unstable board during visual stimulation

    Science.gov (United States)

    Mizuno, Y.; Shindo, M.; Kuno, S.; Kawakita, T.; Watanabe, S.

    2001-08-01

    Concerning with the relation of vection induced by the optokinetic stimulation and the body movement, especially we attended to the neck joint movement, which counteracted to the shoulder movement. Then, we analyzed the mechanisms of the sitting postural control by using the seesaw board. By the optokinetic stimulation through the head mounted display (H.M.D.), the vection was leaded, and it affected to the sway of the body on the seesaw board. In this experiment, we found that the movement of upper part of body except for the head was the same direction to the seesaw board but the head moved out of phase to the seesaw board. This phenomenon will be suggested that the unstable condition of sway is balanced by the counter swing of head and the neck muscle tonus is controlled by acting of the vestiburo-collic reflex.

  8. On-chip power delivery and management

    CERN Document Server

    Vaisband, Inna P; Popovich, Mikhail; Mezhiba, Andrey V; Köse, Selçuk; Friedman, Eby G

    2016-01-01

    This book describes methods for distributing power in high speed, high complexity integrated circuits with power levels exceeding many tens of watts and power supplies below a volt. It provides a broad and cohesive treatment of power delivery and management systems and related design problems, including both circuit network models and design techniques for on-chip decoupling capacitors, providing insight and intuition into the behavior and design of on-chip power distribution systems. Organized into subareas to provide a more intuitive flow to the reader, this fourth edition adds more than a hundred pages of new content, including inductance models for interdigitated structures, design strategies for multi-layer power grids, advanced methods for efficient power grid design and analysis, and methodologies for simultaneously placing on-chip multiple power supplies and decoupling capacitors. The emphasis of this additional material is on managing the complexity of on-chip power distribution networks.

  9. CMOS On-Chip Optoelectronic Neural Interface Device with Integrated Light Source for Optogenetics

    Science.gov (United States)

    Sawadsaringkarn, Y.; Kimura, H.; Maezawa, Y.; Nakajima, A.; Kobayashi, T.; Sasagawa, K.; Noda, T.; Tokuda, T.; Ohta, J.

    2012-03-01

    A novel optoelectronic neural interface device is proposed for target applications in optogenetics for neural science. The device consists of a light emitting diode (LED) array implemented on a CMOS image sensor for on-chip local light stimulation. In this study, we designed a suitable CMOS image sensor equipped with on-chip electrodes to drive the LEDs, and developed a device structure and packaging process for LED integration. The prototype device produced an illumination intensity of approximately 1 mW with a driving current of 2.0 mA, which is expected to be sufficient to activate channelrhodopsin (ChR2). We also demonstrated the functions of light stimulation and on-chip imaging using a brain slice from a mouse as a target sample.

  10. Congestion Prediction Algorithm for Network on Chip

    Directory of Open Access Journals (Sweden)

    Hua Cai

    2013-07-01

    Full Text Available Network on chip (NoC traffic congestion was one of the important reasons for the data transmission performance degradation. In this paper, we presented a congestion judgment algorithm, which was based on neural network. The congestion control algorithm firstly used the hamming network to compute the NoC’s link buffer congestion state, secondly used the competitive network to find the worst congestion node, and then adopted avoiding congested node  routing policy to improve the NoC’s transmission performance. In this paper, the congestion control algorithm can make the data stream as far as possible evenly distributed in the NoC’s nodes and links and reduce the transmission resource competition. The simulation results showed that the congestion control algorithm could achieve better network throughput and average transmission delay.

  11. Open Tiled Manycore System-on-Chip

    OpenAIRE

    Wallentowitz, Stefan; Wagner, Philipp; Tempelmeier, Michael; Wild, Thomas; Herkersdorf, Andreas

    2013-01-01

    Manycore System-on-Chip include an increasing amount of processing elements and have become an important research topic for improvements of both hardware and software. While research can be conducted using system simulators, prototyping requires a variety of components and is very time consuming. With the Open Tiled Manycore System-on-Chip (OpTiMSoC) we aim at building such an environment for use in our and other research projects as prototyping platform. This paper describes the project goal...

  12. Phase-modulating lasers toward on-chip integration.

    Science.gov (United States)

    Kurosaka, Yoshitaka; Hirose, Kazuyoshi; Sugiyama, Takahiro; Takiguchi, Yu; Nomoto, Yoshiro

    2016-07-26

    Controlling laser-beam patterns is indispensable in modern technology, where lasers are typically combined with phase-modulating elements such as diffractive optical elements or spatial light modulators. However, the combination of separate elements is not only a challenge for on-chip miniaturisation but also hinders their integration permitting the switchable control of individual modules. Here, we demonstrate the operation of phase-modulating lasers that emit arbitrarily configurable beam patterns without requiring any optical elements or scanning devices. We introduce a phase-modulating resonator in a semiconductor laser, which allows the concurrent realisation of lasing and phase modulation. The fabricated devices are on-chip-sized, making them suitable for integration. We believe this work will provide a breakthrough in various laser applications such as switchable illumination patterns for bio-medical applications, structured illuminations, and even real three-dimensional or highly realistic displays, which cannot be realised with simple combinations of conventional devices or elements.

  13. PI controller scheme for charge balance in implantable electrical stimulators

    Indian Academy of Sciences (India)

    C Rathna

    2016-01-01

    Electrical stimulation has been used in a wide variety of medical implant applications. In all of these applications, due to safety concerns, maintaining charge balance becomes a critically important issue that needs to be addressed at the design stage. It is important that charge balancing schemes be robust to circuit (process) and load impedance variations, and at the same time must also lend themselves to miniaturization. In this communication, simulation studies on the effectiveness of using Proportional Integral (P-I) control schemes for managing charge balance in electrical stimulation are presented. The adaptation of the P-I control scheme to implant circuits leads to two possible circuit realizations in the analog domain. The governing equations for these realizations are approximated to simple linear equations. Considering typical circuit and tissue parameter values and their expected uncertainties, Matlab as well as circuit simulations have been carried out. Simulation results presented indicate that the tissue voltages settle to well below 20% of the safe levels and within about 20 stimulations cycles, thus confirming the validity and robustness of the proposed schemes.

  14. Power management design for lab-on-chip biosensors.

    Science.gov (United States)

    Xiaojian Yu; Moez, Kambiz; I-Chyn Wey; Jie Chen

    2016-08-01

    Over the past decades, we have witnessed the growth demands of portable lab-on-chip biosensors. These lab-on-chip devices are mostly powered by battery, and intelligent power management systems are required to provide supply voltage for different functional units on biosensors (e.g. a microfluidic control system might require higher voltage than the rest working units of biosensors). In this paper, a fully integrated multiple-stage voltage multiplier is proposed to provide high-voltage power needs. The proposed design was implemented with the IBM's 0.13um CMOS process with a maximum power efficiency of 81.02% and maximum voltage conversion efficiency of 99.8% under a supply voltage of 1.2 V.

  15. Development of Low-Cost Current Controlled Stimulator for Paraplegics

    Directory of Open Access Journals (Sweden)

    Aizan Masdar

    2012-12-01

    Full Text Available A spinal cord injury (SCI has a severe impact on human life in general as well as on the physical status and condition. The use of electrical signals to restore the function of paralyzed muscles is called functional electrical stimulation (FES. FES is a promising way to restore mobility to SCI by applying low-level electrical current to the paralyzed muscles so as to enhance that person’s ability to function and live independently. However, due to the limited number of commercially available FES assisted exerciser systems and their rather high cost, the conventional devices are unaffordable for most peoples. It is also inconvenient because of wired based system that creates a limitation in performing exercise. Thus, this project is concerned with the development of low-cost current controlled stimulator mainly for the paraplegic subjects. The developed device is based on a microcontroller, wireless based system using Zigbee module, voltage-to-current converter circuit and should produce proper monopolar and bipolar current pulses, pulse trains, arbitrary current waveforms, and a trigger output for FES applications. This device has been developed as in the new technique of the stimulator development with low cost and one of the contributing factors in Rehabilitation Engineering for patients with SCI.

  16. Lotus-on-chip: computer-aided design and 3D direct laser writing of bioinspired surfaces for controlling the wettability of materials and devices.

    Science.gov (United States)

    Diaz Lantada, Andres; Hengsbach, Stefan; Bade, Klaus

    2017-07-28

    In this study we present the combination of a math-based design strategy with direct laser writing as high-precision technology for promoting solid free-form fabrication of multi-scale biomimetic surfaces. Results show a remarkable control of surface topography and wettability properties. Different examples of surfaces inspired on the lotus leaf, which to our knowledge are obtained for the first time following a computer-aided design with this degree of precision, are presented. Design and manufacturing strategies towards microfluidic systems whose fluid driving capabilities are obtained just by promoting a design-controlled wettability of their surfaces, are also discussed and illustrated by means of conceptual proofs. According to our experience, the synergies between the presented computer-aided design strategy and the capabilities of direct laser writing, supported by innovative writing strategies to promote final size while maintaining high precision, constitute a relevant step forward towards materials and devices with design-controlled multi-scale and micro-structured surfaces for advanced functionalities. To our knowledge, the surface geometry of the lotus leaf, which has relevant industrial applications thanks to its hydrophobic and self-cleaning behavior, has not yet been adequately modeled and manufactured in an additive way with the degree of precision that we present here. © 2017 IOP Publishing Ltd.

  17. Stimulated Raman adiabatic control of a nuclear spin in diamond

    Science.gov (United States)

    Coto, Raul; Jacques, Vincent; Hétet, Gabriel; Maze, Jerónimo R.

    2017-08-01

    Coherent manipulation of nuclear spins is a highly desirable tool for both quantum metrology and quantum computation. However, most of the current techniques to control nuclear spins lack fast speed, impairing their robustness against decoherence. Here, based on stimulated Raman adiabatic passage, and its modification including shortcuts to adiabaticity, we present a fast protocol for the coherent manipulation of nuclear spins. Our proposed Λ scheme is implemented in the microwave domain and its excited-state relaxation can be optically controlled through an external laser excitation. These features allow for the initialization of a nuclear spin starting from a thermal state. Moreover we show how to implement Raman control for performing Ramsey spectroscopy to measure the dynamical and geometric phases acquired by nuclear spins.

  18. On-chip Magnetic Separation and Cell Encapsulation in Droplets

    Science.gov (United States)

    Chen, A.; Byvank, T.; Bharde, A.; Miller, B. L.; Chalmers, J. J.; Sooryakumar, R.; Chang, W.-J.; Bashir, R.

    2012-02-01

    The demand for high-throughput single cell assays is gaining importance because of the heterogeneity of many cell suspensions, even after significant initial sorting. These suspensions may display cell-to-cell variability at the gene expression level that could impact single cell functional genomics, cancer, stem-cell research and drug screening. The on-chip monitoring of individual cells in an isolated environment could prevent cross-contamination, provide high recovery yield and ability to study biological traits at a single cell level These advantages of on-chip biological experiments contrast to conventional methods, which require bulk samples that provide only averaged information on cell metabolism. We report on a device that integrates microfluidic technology with a magnetic tweezers array to combine the functionality of separation and encapsulation of objects such as immunomagnetically labeled cells or magnetic beads into pico-liter droplets on the same chip. The ability to control the separation throughput that is independent of the hydrodynamic droplet generation rate allows the encapsulation efficiency to be optimized. The device can potentially be integrated with on-chip labeling and/or bio-detection to become a powerful single-cell analysis device.

  19. Stimulation of bioluminescence in Noctiluca sp. using controlled temperature changes.

    Science.gov (United States)

    Han, Jing; Li, GuiJuan; Liu, HuanYing; Hu, HaoHao; Zhang, XueGang

    2013-01-01

    Bioluminescence induced by multifarious stimuli has long been observed and is remains under investigation because of its great complexity. In particular, the exact mechanism underlying bioluminescence is not yet fully understood. This work presents a new experimental method for studying Noctiluca sp. bioluminescence under temperature change stimulation. It is a study of Noctiluca sp. bioluminescence using controlled temperature changes in a tank. A characteristic of this experiment is the large volume of water used (1 m(3) in a tank of 2 × 1 × 1 m). Temperature changes were controlled by two methods. In the first, a flask filled with hot water was introduced into the tank and in the second, a water heater was used in the tank. Temperature changes were recorded using sensors. Noctiluca sp. bioluminescence was recorded using a Canon 5D Mark II and this allowed the characteristics of Noctiluca sp. bioluminescence under temperature change stimulation to be monitored.

  20. Control of directional change after mechanical stimulation in Drosophila

    Directory of Open Access Journals (Sweden)

    Zhou Yating

    2012-10-01

    Full Text Available Abstract Background Proper adjustment of moving direction after external mechanical stimulation is essential for animals to avoid danger (e.g. predators, and thus is vital for survival. This process involves sensory inputs, central processing and motor outputs. Recent studies have made considerable progress in identifying mechanosensitive neurons and mechanosensation receptor proteins. Our understandings of molecular and cellular mechanisms that link mechanosensation with the changes in moving direction, however, remain limited. Results In this study, we investigate the control of movement adjustment in Drosophila. In response to gentle touch at the anterior segments, Drosophila larvae reorient and select a new direction for forward movement. The extent of change in moving direction is correlated with the intensity of tactile stimuli. Sensation of gentle touch requires chordotonal organs and class IV da neurons. Genetic analysis indicates an important role for the evolutionarily conserved immunoglobulin (Ig superfamily protein Turtle (Tutl to regulate touch-initiated directional change. Tutl is required specifically in post-mitotic neurons at larval stage after the completion of embryonic development. Circuit breaking analysis identified a small subset of Tutl-positive neurons that are involved in the adjustment of moving direction. Conclusion We identify Tutl and a small subset of CNS neurons in modulating directional change in response to gentle touch. This study presents an excellent starting point for further dissection of molecular and cellular mechanisms controlling directional adjustment after mechanical stimulation.

  1. Variation Tolerant On-Chip Interconnects

    CERN Document Server

    Nigussie, Ethiopia Enideg

    2012-01-01

    This book presents design techniques, analysis and implementation of high performance and power efficient, variation tolerant on-chip interconnects.  Given the design paradigm shift to multi-core, interconnect-centric designs and the increase in sources of variability and their impact in sub-100nm technologies, this book will be an invaluable reference for anyone concerned with the design of next generation, high-performance electronics systems. Provides comprehensive, circuit-level explanation of high-performance, energy-efficient, variation-tolerant on-chip interconnect; Describes design techniques to mitigate problems caused by variation; Includes techniques for design and implementation of self-timed on-chip interconnect, delay variation insensitive communication protocols, high speed signaling techniques and circuits, bit-width independent completion detection and process, voltage and temperature variation tolerance.                          

  2. Iterative learning control for electrical stimulation and stroke rehabilitation

    CERN Document Server

    Freeman, Chris T; Burridge, Jane H; Hughes, Ann-Marie; Meadmore, Katie L

    2015-01-01

    Iterative learning control (ILC) has its origins in the control of processes that perform a task repetitively with a view to improving accuracy from trial to trial by using information from previous executions of the task. This brief shows how a classic application of this technique – trajectory following in robots – can be extended to neurological rehabilitation after stroke. Regaining upper limb movement is an important step in a return to independence after stroke, but the prognosis for such recovery has remained poor. Rehabilitation robotics provides the opportunity for repetitive task-oriented movement practice reflecting the importance of such intense practice demonstrated by conventional therapeutic research and motor learning theory. Until now this technique has not allowed feedback from one practice repetition to influence the next, also implicated as an important factor in therapy. The authors demonstrate how ILC can be used to adjust external functional electrical stimulation of patients’ mus...

  3. Communication architectures for systems-on-chip

    CERN Document Server

    Ayala, Jose L

    2011-01-01

    A presentation of state-of-the-art approaches from an industrial applications perspective, Communication Architectures for Systems-on-Chip shows professionals, researchers, and students how to attack the problem of data communication in the manufacture of SoC architectures. With its lucid illustration of current trends and research improving the performance, quality, and reliability of transactions, this is an essential reference for anyone dealing with communication mechanisms for embedded systems, systems-on-chip, and multiprocessor architectures--or trying to overcome existing limitations.

  4. Kinetic characterization of on-chip DNA ligation on dendron-coated surfaces with nanoscaled lateral spacings

    Science.gov (United States)

    Kim, Eung-Sam; Lee, Namgyu; Park, Joon Won; Choi, Kwan Yong

    2013-10-01

    We analyzed the enzymatic profiles of on-chip DNA ligation as we controlled the lateral spacing of surface-immobilized DNA substrates using dendron molecules with different sizes at the nanoscale. Enzymatic on-chip DNA ligation was performed on the dendron-coated surface within 20 min with no need for post-ligation gel electrophoresis. The enzymatic DNA repair was assessed by the fluorescence intensity at the repaired DNA duplex after thermally dissociating the unligated Cy3-labeled DNA from the DNA duplex, in which the Cy3-labeled DNA was hybridized prior to the on-chip DNA ligation. The rate of the nick-sealing reaction on the 27-acid dendron surface was 3-fold higher than that on the 9-acid dendron surface, suggesting that the wider lateral spacing determined by the larger dendron molecule could facilitate the access of DNA ligase to the nick site. The performance of on-chip DNA ligation was dropped to 10% and 3% when the nick was replaced by one- and two-nucleotide-long gaps, respectively. The 5‧ terminal phosphorylation of DNA strands by polynucleotide kinase and the on-chip DNA cleavage by endonucleases were also quantitatively monitored throughout the on-chip DNA ligation on the dendron-coated surface. A better understanding of the enzymatic kinetics of on-chip DNA ligation will contribute to a more reliable performance of various on-chip DNA ligation-based assays.

  5. Endocrine system on chip for a diabetes treatment model.

    Science.gov (United States)

    Nguyen, Dao Thi Thuy; van Noort, Danny; Jeong, In-Kyung; Park, Sungsu

    2017-02-21

    The endocrine system is a collection of glands producing hormones which, among others, regulates metabolism, growth and development. One important group of endocrine diseases is diabetes, which is caused by a deficiency or diminished effectiveness of endogenous insulin. By using a microfluidic perfused 3D cell-culture chip, we developed an 'endocrine system on chip' to potentially be able to screen drugs for the treatment of diabetes by measuring insulin release over time. Insulin-secreting β-cells are located in the pancreas, while L-cells, located in the small intestines, stimulate insulin secretion. Thus, we constructed a co-culture of intestinal-pancreatic cells to measure the effect of glucose on the production of glucagon-like peptide-1 (GLP-1) from the L-cell line (GLUTag) and insulin from the pancreatic β-cell line (INS-1). After three days of culture, both cell lines formed aggregates, exhibited 3D cell morphology, and showed good viability (>95%). We separately measured the dynamic profile of GLP-1 and insulin release at glucose concentrations of 0.5 and 20 mM, as well as the combined effect of GLP-1 on insulin production at these glucose concentrations. In response to glucose stimuli, GLUTag and INS-1 cells produced higher amounts of GLP-1 and insulin, respectively, compared to a static 2D cell culture. INS-1 combined with GLUTag cells exhibited an even higher insulin production in response to glucose stimulation. At higher glucose concentrations, the diabetes model on chip showed faster saturation of the insulin level. Our results suggest that the endocrine system developed in this study is a useful tool for observing dynamical changes in endocrine hormones (GLP-1 and insulin) in a glucose-dependent environment. Moreover, it can potentially be used to screen GLP-1 analogues and natural insulin and GLP-1 stimulants for diabetes treatment.

  6. FUNCTIONAL ELECTRICAL STIMULATION FOR CONTROL OF EPILEPTIC SEIZURES

    DEFF Research Database (Denmark)

    Jiao, Jianhang

    parameters regarding their ability to inhibit seizures. The present thesis hypothesized that the antiepileptic effects of vagus nerve stimulation and spinal cord stimulation could be improved by using higher stimulation frequencies than those that are currently used in clinic or proposed in the literature....

  7. Controllable single photon stimulation of retinal rod cells

    CERN Document Server

    Phan, Nam Mai; Bessarab, Dmitri A; Krivitsky, Leonid A

    2013-01-01

    Retinal rod cells are commonly assumed to be sensitive to single photons [1, 2, 3]. Light sources used in prior experiments exhibit unavoidable fluctuations in the number of emitted photons [4]. This leaves doubt about the exact number of photons used to stimulate the rod cell. In this letter, we interface rod cells of Xenopus laevis with a light source based on Spontaneous Parametric Down Conversion (SPDC) [5], which provides one photon at a time. Precise control of generation of single photons and directional delivery enables us to provide unambiguous proof of single photon sensitivity of rod cells without relying on the statistical assumptions. Quantum correlations between single photons in the SPDC enable us to determine quantum efficiency of the rod cell without pre-calibrated reference detectors [6, 7, 8]. These results provide the path for exploiting resources offered by quantum optics in generation and manipulation of light in visual studies. From a more general perspective, this method offers the ult...

  8. On-chip mode division multiplexing technologies

    DEFF Research Database (Denmark)

    Ding, Yunhong; Frellsen, Louise Floor; Guan, Xiaowei

    2016-01-01

    using one-dimensional (1D) photonic crystal silicon waveguides. We furthermore use the fabricated devices to demonstrate on-chip point-to-point mode division multiplexing transmission, and all-optical signal processing by mode-selective wavelength conversion. Finally, we report an efficient silicon...

  9. On-chip entangled photon source

    Energy Technology Data Exchange (ETDEWEB)

    Soh, Daniel B. S.; Bisson, Scott E.

    2016-11-22

    Various technologies pertaining to an on-chip entangled photon source are described herein. A light source is used to pump two resonator cavities that are resonant at two different respective wavelengths and two different respective polarizations. The resonator cavities are coupled to a four-wave mixing cavity that receives the light at the two wavelengths and outputs polarization-entangled photons.

  10. Improving Myoelectric Control for Amputees through Transcranial Direct Current Stimulation.

    Science.gov (United States)

    Pan, Lizhi; Zhang, Dingguo; Sheng, Xinjun; Zhu, Xiangyang

    2015-08-01

    Most prosthetic myoelectric control studies have shown good performance for unimpaired subjects. However, performance is generally unacceptable for amputees. The primary problem is the poor quality of electromyography (EMG) signals of amputees compared with healthy individuals. To improve clinical performance of myoelectric control, this study explored transcranial direct current stimulation (tDCS) to modulate brain activity and enhance EMG quality. We tested six unilateral transradial amputees by applying active and sham anodal tDCS separately on two different days. Surface EMG signals were acquired from the affected and intact sides for 11 hand and wrist motions in the pre-tDCS and post-tDCS sessions. Autoregression coefficients and linear discriminant analysis classifiers were used to process the EMG data for pattern recognition of the 11 motions. For the affected side, active anodal tDCS significantly reduced the average classification error rate (CER) by 10.1%, while sham tDCS had no such effect. For the intact side, the average CER did not change on the day of sham tDCS but increased on the day of active tDCS. These results demonstrated that tDCS could modulate brain function and improve EMG-based classification performance for amputees. It has great potential in dramatically reducing the length of learning process of amputees for effectively using myoelectrically controlled multifunctional prostheses.

  11. Modelling, Synthesis, and Configuration of Networks-on-Chips

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo

    This thesis presents three contributions in two different areas of network-on-chip and system-on-chip research: Application modelling and identifying and solving different optimization problems related to two specific network-on-chip architectures. The contribution related to application modellin...... for solving the network synthesis problem in the MANGO network-on-chip, and the identification and formalization of the ReNoC configuration problem together with three heuristics for solving it....

  12. Functional Neuromuscular Stimulation Controlled by Surface Electromyographic Signals Produced by Volitional Activation of the Same Muscle

    DEFF Research Database (Denmark)

    Sennels, Søren; Biering-Sørensen, Fin; Andersen, Ole Trier

    1997-01-01

    In order to use the volitional electromyography (EMG) as a control signal for the stimulation of the same muscle, it is necessary to eliminate the stimulation artifacts and the muscle responses caused by the stimulation. The stimulation artifacts, caused by the electric field in skin and tissue...... generated by the stimulation current, are relatively easy to eliminate by shutting down the EMG-amplifier at the onset of the stimulation pulses. The muscle response is a nonstationary signal, therefore, an adaptive linear prediction filter is proposed. The filter is implemented and for three filter lengths...... the shut-down circuit and the adaptive filter both the stimulation artifacts and the muscle responses can be effectively eliminated from the EMG signal from a stimulated muscle. It is therefore possible to extract the volitional EMG from a partly paralyzed muscle and use it for controlling the stimulation...

  13. Packetizing OCP Transactions in the MANGO Network-on-Chip

    DEFF Research Database (Denmark)

    Bjerregaard, Tobias; Sparsø, Jens

    2006-01-01

    The scaling of CMOS technology causes a widening gap between the performance of on-chip communication and computation. This calls for a communication-centric design flow. The MANGO network-on-chip architecture enables globally asynchronous locally synchronous (GALS) system-on-chip design, while...

  14. Controlled pseudopod extension of human neutrophils stimulated with different chemoattractants.

    Science.gov (United States)

    Zhelev, Doncho V; Alteraifi, Abdullatif M; Chodniewicz, David

    2004-07-01

    The formation of pseudopods and lamellae after ligation of chemoattractant sensitive G-protein coupled receptors (GPCRs) is essential for chemotaxis. Here, pseudopod extension was stimulated with chemoattractant delivered from a micropipet. The chemoattractant diffusion and convection mass transport were considered, and it is shown that when the delivery of chemoattractant was limited by diffusion there was a strong chemoattractant gradient along the cell surface. The diffusion-limited delivery of chemoattractant from a micropipet allowed for maintaining an almost constant chemoattractant concentration at the leading edge of single pseudopods during their growth. In these conditions, the rate of pseudopod extension was dependent on the concentration of chemoattractant in the pipet delivering chemoattractant. The pseudopod extension induced using micropipets was oscillatory even in the presence of a constant delivery of chemoattractant. This oscillatory pseudopod extension was controlled by activated RhoA and its downstream effector kinase ROCK and was abolished after the inhibition of RhoA activation with Clostridium botulinium C3 exoenzyme (C3) or the blocking of ROCK activation with Y-27632. The ability of the micropipet assay to establish a well-defined chemoattractant distribution around the activated cell over a wide range of molecular weights of the used chemoattractants allowed for comparison of the effect of chemoattractant stimulation on the dynamics of pseudopod growth. Pseudopod growth was stimulated using N-formylated peptide (N-formyl-methionyl-leucyl-phenylalanine (fMLP)), platelet activating factor (PAF), leukotriene B4 (LTB(4)), C5a anaphylotoxin (C5a), and interleukin-8 (IL-8), which represent the typical ligands for G-protein coupled chemotactic receptors. The dependence of the rate of pseudopod extension on the concentration of these chemoattractants and their equimolar mixture was measured and shown to be similar for all chemoattractants. The

  15. A Time-predictable Memory Network-on-Chip

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Chong, David VH; Puffitsch, Wolfgang

    2014-01-01

    To derive safe bounds on worst-case execution times (WCETs), all components of a computer system need to be time-predictable: the processor pipeline, the caches, the memory controller, and memory arbitration on a multicore processor. This paper presents a solution for time-predictable memory...... arbitration and access for chip-multiprocessors. The memory network-on-chip is organized as a tree with time-division multiplexing (TDM) of accesses to the shared memory. The TDM based arbitration completely decouples processor cores and allows WCET analysis of the memory accesses on individual cores without...

  16. Microarchitecture of network-on-chip routers a designer's perspective

    CERN Document Server

    Dimitrakopoulos, Giorgos; Seitanidis, Ioannis

    2014-01-01

    This book provides a unified overview of network-on-chip router micro-architecture, the corresponding design opportunities and challenges, and existing solutions to overcome these challenges. The discussion focuses on the heart of a NoC, the NoC router, and how it interacts with the rest of the system. Coverage includes both basic and advanced design techniques that cover the entire router design space including router organization, flow control, pipelined operation, buffering architectures, as well as allocators' structure and algorithms. Router micro-architectural options are presented in a

  17. A Time-predictable Memory Network-on-Chip

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Chong, David VH; Puffitsch, Wolfgang

    2014-01-01

    To derive safe bounds on worst-case execution times (WCETs), all components of a computer system need to be time-predictable: the processor pipeline, the caches, the memory controller, and memory arbitration on a multicore processor. This paper presents a solution for time-predictable memory...... arbitration and access for chip-multiprocessors. The memory network-on-chip is organized as a tree with time-division multiplexing (TDM) of accesses to the shared memory. The TDM based arbitration completely decouples processor cores and allows WCET analysis of the memory accesses on individual cores without...

  18. On-chip Inter-modal Brillouin Scattering

    CERN Document Server

    Kittlaus, Eric A; Rakich, Peter T

    2016-01-01

    Stimulated Brillouin interactions mediate nonlinear coupling between photons and acoustic phonons through an optomechanical three-wave interaction. Though these nonlinearities were previously very weak in silicon photonic systems, the recent emergence of new optomechanical waveguide structures have transformed Brillouin processes into one of the strongest and most tailorable on-chip nonlinear interactions. New technologies based on Brillouin couplings have formed a basis for amplification, filtering, and nonreciprocal signal processing techniques. In this paper, we demonstrate strong guided-wave Brillouin scattering between light fields guided in distinct spatial modes of a silicon waveguide for the first time. This inter-modal coupling creates dispersive symmetry breaking between Stokes and anti-Stokes processes, permitting single-sideband amplification and wave dynamics that permit near-unity power conversion. Combining these physics with integrated mode-multiplexers enables novel device topologies and elim...

  19. On-chip antenna: Practical design and characterization considerations

    KAUST Repository

    Shamim, Atif

    2012-07-28

    This paper highlights the challenges of an emergent field, namely, on-chip antenna design. Consistent with the RF System-on-Chip (SoC) concept, co-design strategy for circuits and on-chip antennas is described. A number of design and layout issues, arising from the highly integrated nature of this kind of systems, are discussed. The characterization difficulties related to on-chip antennas radiation properties are also highlighted. Finally, a novel on-wafer test fixture is proposed to measure the gain and radiation pattern of the on-chip antennas in the anechoic chamber.

  20. On-Chip Single-Photon Sifter

    CERN Document Server

    Elshaari, Ali W; Fognini, Andreas; Reimer, Michael E; Dalacu, Dan; Poole, Philip J; Zwiller, Val; Jöns, Klaus D

    2016-01-01

    Quantum states of light play a pivotal role in modern science[1] and future photonic applications[2]. While impressive progress has been made in their generation and manipulation with high fidelities, the common table-top approach is reaching its limits for practical quantum applications. Since the advent of integrated quantum nanophotonics[3] different material platforms based on III-V nanostructures-, color centers-, and nonlinear waveguides[4-8] as on-chip light sources have been investigated. Each platform has unique advantages and limitations in terms of source properties, optical circuit complexity, and scaling potentials. However, all implementations face major challenges with efficient and tunable filtering of individual quantum states[4], scalable integration and deterministic multiplexing of on-demand selected quantum emitters[9], and on-chip excitation-suppression[10]. Here we overcome all of these challenges with a novel hybrid and scalable nanofabrication approach to generate quantum light on-chi...

  1. On-Chip Microwave Quantum Hall Circulator

    Science.gov (United States)

    Mahoney, A. C.; Colless, J. I.; Pauka, S. J.; Hornibrook, J. M.; Watson, J. D.; Gardner, G. C.; Manfra, M. J.; Doherty, A. C.; Reilly, D. J.

    2017-01-01

    Circulators are nonreciprocal circuit elements that are integral to technologies including radar systems, microwave communication transceivers, and the readout of quantum information devices. Their nonreciprocity arises from the interference of microwaves over the centimeter scale of the signal wavelength, in the presence of bulky magnetic media that breaks time-reversal symmetry. Here, we realize a completely passive on-chip microwave circulator with size 1 /1000 th the wavelength by exploiting the chiral, "slow-light" response of a two-dimensional electron gas in the quantum Hall regime. For an integrated GaAs device with 330 μ m diameter and about 1-GHz center frequency, a nonreciprocity of 25 dB is observed over a 50-MHz bandwidth. Furthermore, the nonreciprocity can be dynamically tuned by varying the voltage at the port, an aspect that may enable reconfigurable passive routing of microwave signals on chip.

  2. On-chip plasmonic waveguide optical waveplate

    Science.gov (United States)

    Gao, Linfei; Huo, Yijie; Zang, Kai; Paik, Seonghyun; Chen, Yusi; Harris, James S.; Zhou, Zhiping

    2015-10-01

    Polarization manipulation is essential in almost every photonic system ranging from telecommunications to bio-sensing to quantum information. This is traditionally achieved using bulk waveplates. With the developing trend of photonic systems towards integration and miniaturization, the need for an on-chip waveguide type waveplate becomes extremely urgent. However, this is very challenging using conventional dielectric waveguides, which usually require complex 3D geometries to alter the waveguide symmetry and are also difficult to create an arbitrary optical axis. Recently, a waveguide waveplate was realized using femtosecond laser writing, but the device length is in millimeter range. Here, for the first time we propose and experimentally demonstrate an ultracompact, on-chip waveplate using an asymmetric hybrid plasmonic waveguide to create an arbitrary optical axis. The device is only in several microns length and produced in a flexible integratable IC compatible format, thus opening up the potential for integration into a broad range of systems.

  3. Microengineered physiological biomimicry: organs-on-chips.

    Science.gov (United States)

    Huh, Dongeun; Torisawa, Yu-suke; Hamilton, Geraldine A; Kim, Hyun Jung; Ingber, Donald E

    2012-06-21

    Microscale engineering technologies provide unprecedented opportunities to create cell culture microenvironments that go beyond current three-dimensional in vitro models by recapitulating the critical tissue-tissue interfaces, spatiotemporal chemical gradients, and dynamic mechanical microenvironments of living organs. Here we review recent advances in this field made over the past two years that are focused on the development of 'Organs-on-Chips' in which living cells are cultured within microfluidic devices that have been microengineered to reconstitute tissue arrangements observed in living organs in order to study physiology in an organ-specific context and to develop specialized in vitro disease models. We discuss the potential of organs-on-chips as alternatives to conventional cell culture models and animal testing for pharmaceutical and toxicology applications. We also explore challenges that lie ahead if this field is to fulfil its promise to transform the future of drug development and chemical safety testing.

  4. Tunable on chip optofluidic laser

    DEFF Research Database (Denmark)

    Bakal, Avraham; Vannahme, Christoph; Kristensen, Anders

    2015-01-01

    A chip scale tunable laser in the visible spectral band is realized by generating a periodic droplet array inside a microfluidic channel. Combined with a gain medium within the droplets, the periodic structure provides the optical feedback of the laser. By controlling the pressure applied to two...... separate inlets we can change the period of the droplet array. As a result, the lasing frequency is tuned over a broad spectral range. Using this configuration, we demonstrate wavelength tunability of about 70 nm and lasing threshold of about 15 μJ/mm2....

  5. Repetitive transcranial magnetic stimulator with controllable pulse parameters

    Science.gov (United States)

    Peterchev, Angel V.; Murphy, David L.; Lisanby, Sarah H.

    2011-06-01

    The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency.

  6. Snoezelen or Controlled Multisensory Stimulation. Treatment Aspects from Israel

    Directory of Open Access Journals (Sweden)

    Joav Merrick

    2004-01-01

    Full Text Available In Israel today, with a total population of over 6 million persons, the Division for Mental Retardation (DMR provides services to 23,000 persons with intellectual disability (ID. Of the 23,000, residential services are provided to more than 6,000 in close to 60 residential centers, another 2,000 are provided residential care in hostels or group homes in the community in about 50 locations, while the rest are served with day-care kindergarten, day-treatment centers, sheltered workshops, or integrated care in the community. The first Snoezelen room (controlled multisensory stimulation in the DMR was established at the Bnei Zion residential care center in 1995. The Snoezelen method is now used in Israel in more than 30 residential care centers and 3 community settings. Since the year 2000, a physiotherapist has been employed in order to supervise the treatment and development of the method nationally. Professional staff meetings take place every 4 months. A certification course has been established on a national basis for individuals from different professions (occupational therapists, physiotherapists, teachers, music therapists, nurses, speech therapists, or caregivers. Snoezelen has proved to be an important instrument and a powerful therapeutic tool among the various treatment modules employed in Israel for persons with ID. This paper presents the concept illustrated with two case stories.

  7. Acupoints Stimulation for Anxiety and Depression in Cancer Patients: A Quantitative Synthesis of Randomized Controlled Trials

    OpenAIRE

    2016-01-01

    This study aims at concluding the current evidence on the therapeutic effects of acupoints stimulation for cancer patients with anxiety and depression. Randomized controlled trials using acupoints stimulation for relieving anxiety and/or depression in cancer patients were searched, and 11 studies were finally included, of which eight trials compared acupoints stimulation with standard methods of treatment/care, and acupoints stimulation showed significantly better effects in improving depress...

  8. Microfabrication of human organs-on-chips.

    Science.gov (United States)

    Huh, Dongeun; Kim, Hyun Jung; Fraser, Jacob P; Shea, Daniel E; Khan, Mohammed; Bahinski, Anthony; Hamilton, Geraldine A; Ingber, Donald E

    2013-11-01

    'Organs-on-chips' are microengineered biomimetic systems containing microfluidic channels lined by living human cells, which replicate key functional units of living organs to reconstitute integrated human organ-level pathophysiology in vitro. These microdevices can be used to test efficacy and toxicity of drugs and chemicals, and to create in vitro models of human disease. Thus, they potentially represent low-cost alternatives to conventional animal models for pharmaceutical, chemical and environmental applications. Here we describe a protocol for the fabrication, microengineering and operation of these microfluidic organ-on-chip systems. First, microengineering is used to fabricate a multilayered microfluidic device that contains two parallel elastomeric microchannels separated by a thin porous flexible membrane, along with two full-height, hollow vacuum chambers on either side; this requires ∼3.5 d to complete. To create a 'breathing' lung-on-a-chip that mimics the mechanically active alveolar-capillary interface of the living human lung, human alveolar epithelial cells and microvascular endothelial cells are cultured in the microdevice with physiological flow and cyclic suction applied to the side chambers to reproduce rhythmic breathing movements. We describe how this protocol can be easily adapted to develop other human organ chips, such as a gut-on-a-chip lined by human intestinal epithelial cells that experiences peristalsis-like motions and trickling fluid flow. Also, we discuss experimental techniques that can be used to analyze the cells in these organ-on-chip devices.

  9. Routing algorithms in networks-on-chip

    CERN Document Server

    Daneshtalab, Masoud

    2014-01-01

    This book provides a single-source reference to routing algorithms for Networks-on-Chip (NoCs), as well as in-depth discussions of advanced solutions applied to current and next generation, many core NoC-based Systems-on-Chip (SoCs). After a basic introduction to the NoC design paradigm and architectures, routing algorithms for NoC architectures are presented and discussed at all abstraction levels, from the algorithmic level to actual implementation.  Coverage emphasizes the role played by the routing algorithm and is organized around key problems affecting current and next generation, many-core SoCs. A selection of routing algorithms is included, specifically designed to address key issues faced by designers in the ultra-deep sub-micron (UDSM) era, including performance improvement, power, energy, and thermal issues, fault tolerance and reliability.   ·         Provides a comprehensive overview of routing algorithms for Networks-on-Chip and NoC-based, manycore systems; ·         Describe...

  10. On-chip cell analysis platform: Implementation of contact fluorescence microscopy in microfluidic chips

    Science.gov (United States)

    Takehara, Hiroaki; Kazutaka, Osawa; Haruta, Makito; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Ohta, Jun

    2017-09-01

    Although fluorescence microscopy is the gold standard tool for biomedical research and clinical applications, their use beyond well-established laboratory infrastructures remains limited. The present study investigated a novel on-chip cell analysis platform based on contact fluorescence microscopy and microfluidics. Combined use of a contact fluorescence imager based on complementary metal-oxide semiconductor technology and an ultra-thin glass bottom microfluidic chip enabled both to observe living cells with minimal image distortion and to ease controlling and handling of biological samples (e.g. cells and biological molecules) in the imaged area. A proof-of-concept experiment of on-chip detection of cellular response to endothelial growth factor demonstrated promising use for the recently developed on-chip cell analysis platform. Contact fluorescence microscopy has numerous desirable features including compatibility with plastic microfluidic chips and compatibility with the electrical control system, and thus will fulfill the requirements of a fully automated cell analysis system.

  11. A Power-Efficient Wireless System With Adaptive Supply Control for Deep Brain Stimulation

    Science.gov (United States)

    Lee, Hyung-Min; Park, Hangue; Ghovanloo, Maysam

    2014-01-01

    A power-efficient wireless stimulating system for a head-mounted deep brain stimulator (DBS) is presented. A new adaptive rectifier generates a variable DC supply voltage from a constant AC power carrier utilizing phase control feedback, while achieving high AC-DC power conversion efficiency (PCE) through active synchronous switching. A current-controlled stimulator adopts closed-loop supply control to automatically adjust the stimulation compliance voltage by detecting stimulation site potentials through a voltage readout channel, and improve the stimulation efficiency. The stimulator also utilizes closed-loop active charge balancing to maintain the residual charge at each site within a safe limit, while receiving the stimulation parameters wirelessly from the amplitude-shift-keyed power carrier. A 4-ch wireless stimulating system prototype was fabricated in a 0.5-μm 3M2P standard CMOS process, occupying 2.25 mm². With 5 V peak AC input at 2 MHz, the adaptive rectifier provides an adjustable DC output between 2.5 V and 4.6 V at 2.8 mA loading, resulting in measured PCE of 72 ~ 87%. The adaptive supply control increases the stimulation efficiency up to 30% higher than a fixed supply voltage to 58 ~ 68%. The prototype wireless stimulating system was verified in vitro. PMID:24678126

  12. Comparison of Twitch Responses During Current- or Voltage-Controlled Transcutaneous Neuromuscular Electrical Stimulation.

    Science.gov (United States)

    Vargas Luna, José Luis; Krenn, Matthias; Löfler, Stefan; Kern, Helmut; Cortés R, Jorge A; Mayr, Winfried

    2015-10-01

    Neuromuscular electrical stimulation (NMES) is an established method for functional restoration of muscle function, rehabilitation, and diagnostics. In this work, NMES was applied with surface electrodes placed on the anterior thigh to identify the main differences between current-controlled (CC) and voltage-controlled (VC) modes. Measurements of the evoked knee extension force and the myoelectric signal of quadriceps and hamstrings were taken during stimulation with different amplitudes, pulse widths, and stimulation techniques. The stimulation pulses were rectangular and symmetric biphasic for both stimulation modes. The electrode-tissue impedance influences the differences between CC and VC stimulation. The main difference is that for CC stimulation, variation of pulse width and amplitude influences the amount of nerve depolarization, whereas VC stimulation is only dependent on amplitude variations for pulse widths longer than 150 μs. An important remark is that these findings are strongly dependent on the characteristics of the electrode-skin interface. In our case, we used large stimulation electrodes placed on the anterior thigh, which cause higher capacitive effects. The controllability, voltage compliance, and charge characteristics of each stimulation technique should be considered during the stimulators design. For applications that require the activation of a large amount of nerve fibers, VC is a more suitable option. In contrast, if the application requires a high controllability, then CC should be chosen prior to VC.

  13. Toward rational design of electrical stimulation strategies for epilepsy control

    OpenAIRE

    2009-01-01

    Electrical stimulation is emerging as a viable alternative for epilepsy patients whose seizures are not alleviated by drugs or surgery. Its attractions are temporal and spatial specificity of action, flexibility of waveform parameters and timing, and the perception that its effects are reversible unlike resective surgery. However, despite significant advances in our understanding of mechanisms of neural electrical stimulation, clinical electrotherapy for seizures relies heavily on empirical t...

  14. A solvent resistant lab-on-chip platform for radiochemistry applications.

    Science.gov (United States)

    Rensch, Christian; Lindner, Simon; Salvamoser, Ruben; Leidner, Stephanie; Böld, Christoph; Samper, Victor; Taylor, David; Baller, Marko; Riese, Stefan; Bartenstein, Peter; Wängler, Carmen; Wängler, Björn

    2014-07-21

    The application of microfluidics to the synthesis of Positron Emission Tomography (PET) tracers has been explored for more than a decade. Microfluidic benefits such as superior temperature control have been successfully applied to PET tracer synthesis. However, the design of a compact microfluidic platform capable of executing a complete PET tracer synthesis workflow while maintaining prospects for commercialization remains a significant challenge. This study uses an integral system design approach to tackle commercialization challenges such as the material to process compatibility with a path towards cost effective lab-on-chip mass manufacturing from the start. It integrates all functional elements required for a simple PET tracer synthesis into one compact radiochemistry platform. For the lab-on-chip this includes the integration of on-chip valves, on-chip solid phase extraction (SPE), on-chip reactors and a reversible fluid interface while maintaining compatibility with all process chemicals, temperatures and chip mass manufacturing techniques. For the radiochemistry device it includes an automated chip-machine interface enabling one-move connection of all valve actuators and fluid connectors. A vial-based reagent supply as well as methods to transfer reagents efficiently from the vials to the chip has been integrated. After validation of all those functional elements, the microfluidic platform was exemplarily employed for the automated synthesis of a Gastrin-releasing peptide receptor (GRP-R) binding the PEGylated Bombesin BN(7-14)-derivative ([(18)F]PESIN) based PET tracer.

  15. Seizure Control in a Computational Model Using a Reinforcement Learning Stimulation Paradigm.

    Science.gov (United States)

    Nagaraj, Vivek; Lamperski, Andrew; Netoff, Theoden I

    2016-11-02

    Neuromodulation technologies such as vagus nerve stimulation and deep brain stimulation, have shown some efficacy in controlling seizures in medically intractable patients. However, inherent patient-to-patient variability of seizure disorders leads to a wide range of therapeutic efficacy. A patient specific approach to determining stimulation parameters may lead to increased therapeutic efficacy while minimizing stimulation energy and side effects. This paper presents a reinforcement learning algorithm that optimizes stimulation frequency for controlling seizures with minimum stimulation energy. We apply our method to a computational model called the epileptor. The epileptor model simulates inter-ictal and ictal local field potential data. In order to apply reinforcement learning to the Epileptor, we introduce a specialized reward function and state-space discretization. With the reward function and discretization fixed, we test the effectiveness of the temporal difference reinforcement learning algorithm (TD(0)). For periodic pulsatile stimulation, we derive a relation that describes, for any stimulation frequency, the minimal pulse amplitude required to suppress seizures. The TD(0) algorithm is able to identify parameters that control seizures quickly. Additionally, our results show that the TD(0) algorithm refines the stimulation frequency to minimize stimulation energy thereby converging to optimal parameters reliably. An advantage of the TD(0) algorithm is that it is adaptive so that the parameters necessary to control the seizures can change over time. We show that the algorithm can converge on the optimal solution in simulation with slow and fast inter-seizure intervals.

  16. On-chip optical phase locking of single growth monolithically integrated Slotted Fabry Perot lasers.

    Science.gov (United States)

    Morrissey, P E; Cotter, W; Goulding, D; Kelleher, B; Osborne, S; Yang, H; O'Callaghan, J; Roycroft, B; Corbett, B; Peters, F H

    2013-07-15

    This work investigates the optical phase locking performance of Slotted Fabry Perot (SFP) lasers and develops an integrated variable phase locked system on chip for the first time to our knowledge using these lasers. Stable phase locking is demonstrated between two SFP lasers coupled on chip via a variable gain waveguide section. The two lasers are biased differently, one just above the threshold current of the device with the other at three times this value. The coupling between the lasers can be controlled using the variable gain section which can act as a variable optical attenuator or amplifier depending on bias. Using this, the width of the stable phase locking region on chip is shown to be variable.

  17. Blood cleaner on-chip design for artificial human kidney manipulation.

    Science.gov (United States)

    Suwanpayak, N; Jalil, M A; Aziz, M S; Ismail, F D; Ali, J; Yupapin, P P

    2011-01-01

    A novel design of a blood cleaner on-chip using an optical waveguide known as a PANDA ring resonator is proposed. By controlling some suitable parameters, the optical vortices (gradient optical fields/wells) can be generated and used to form the trapping tools in the same way as optical tweezers. In operation, the trapping force is formed by the combination between the gradient field and scattering photons by using the intense optical vortices generated within the PANDA ring resonator. This can be used for blood waste trapping and moves dynamically within the blood cleaner on-chip system (artificial kidney), and is performed within the wavelength routers. Finally, the blood quality test is exploited by the external probe before sending to the destination. The advantage of the proposed kidney on-chip system is that the unwanted substances can be trapped and filtered from the artificial kidney, which can be available for blood cleaning applications.

  18. Control of triceps surae stimulation based on shank orientation using a uniaxial gyroscope during gait

    NARCIS (Netherlands)

    Monaghan, C.C.; Riel, W.J.B.M.; Veltink, P.H.

    2009-01-01

    This article presents a stimulation control method using a uniaxial gyroscope measuring angular velocity of the shank in the sagittal plane, to control functional electrical stimulation of the triceps surae to improve push-off of stroke subjects during gait. The algorithm is triggered during each sw

  19. 3D Printing of Organs-On-Chips.

    Science.gov (United States)

    Yi, Hee-Gyeong; Lee, Hyungseok; Cho, Dong-Woo

    2017-01-25

    Organ-on-a-chip engineering aims to create artificial living organs that mimic the complex and physiological responses of real organs, in order to test drugs by precisely manipulating the cells and their microenvironments. To achieve this, the artificial organs should to be microfabricated with an extracellular matrix (ECM) and various types of cells, and should recapitulate morphogenesis, cell differentiation, and functions according to the native organ. A promising strategy is 3D printing, which precisely controls the spatial distribution and layer-by-layer assembly of cells, ECMs, and other biomaterials. Owing to this unique advantage, integration of 3D printing into organ-on-a-chip engineering can facilitate the creation of micro-organs with heterogeneity, a desired 3D cellular arrangement, tissue-specific functions, or even cyclic movement within a microfluidic device. Moreover, fully 3D-printed organs-on-chips more easily incorporate other mechanical and electrical components with the chips, and can be commercialized via automated massive production. Herein, we discuss the recent advances and the potential of 3D cell-printing technology in engineering organs-on-chips, and provides the future perspectives of this technology to establish the highly reliable and useful drug-screening platforms.

  20. 3D Printing of Organs-On-Chips

    Science.gov (United States)

    Yi, Hee-Gyeong; Lee, Hyungseok; Cho, Dong-Woo

    2017-01-01

    Organ-on-a-chip engineering aims to create artificial living organs that mimic the complex and physiological responses of real organs, in order to test drugs by precisely manipulating the cells and their microenvironments. To achieve this, the artificial organs should to be microfabricated with an extracellular matrix (ECM) and various types of cells, and should recapitulate morphogenesis, cell differentiation, and functions according to the native organ. A promising strategy is 3D printing, which precisely controls the spatial distribution and layer-by-layer assembly of cells, ECMs, and other biomaterials. Owing to this unique advantage, integration of 3D printing into organ-on-a-chip engineering can facilitate the creation of micro-organs with heterogeneity, a desired 3D cellular arrangement, tissue-specific functions, or even cyclic movement within a microfluidic device. Moreover, fully 3D-printed organs-on-chips more easily incorporate other mechanical and electrical components with the chips, and can be commercialized via automated massive production. Herein, we discuss the recent advances and the potential of 3D cell-printing technology in engineering organs-on-chips, and provides the future perspectives of this technology to establish the highly reliable and useful drug-screening platforms. PMID:28952489

  1. 3D Printing of Organs-On-Chips

    Directory of Open Access Journals (Sweden)

    Hee-Gyeong Yi

    2017-01-01

    Full Text Available Organ-on-a-chip engineering aims to create artificial living organs that mimic the complex and physiological responses of real organs, in order to test drugs by precisely manipulating the cells and their microenvironments. To achieve this, the artificial organs should to be microfabricated with an extracellular matrix (ECM and various types of cells, and should recapitulate morphogenesis, cell differentiation, and functions according to the native organ. A promising strategy is 3D printing, which precisely controls the spatial distribution and layer-by-layer assembly of cells, ECMs, and other biomaterials. Owing to this unique advantage, integration of 3D printing into organ-on-a-chip engineering can facilitate the creation of micro-organs with heterogeneity, a desired 3D cellular arrangement, tissue-specific functions, or even cyclic movement within a microfluidic device. Moreover, fully 3D-printed organs-on-chips more easily incorporate other mechanical and electrical components with the chips, and can be commercialized via automated massive production. Herein, we discuss the recent advances and the potential of 3D cell-printing technology in engineering organs-on-chips, and provides the future perspectives of this technology to establish the highly reliable and useful drug-screening platforms.

  2. Application of Ferrite Nanomaterial in RF On-Chip Inductors

    Directory of Open Access Journals (Sweden)

    Hua-Lin Cai

    2013-01-01

    Full Text Available Several kinds of ferrite-integrated on-chip inductors are presented. Ferrite nanomaterial applied in RF on-chip inductors is prepared and analyzed to show the properties of high permeability, high ferromagnetic resonance frequency, high resistivity, and low loss, which has the potential that will improve the performance of RF on-chip inductors. Simulations of different coil and ferrite nanomaterial parameters, inductor structures, and surrounding structures are also conducted to achieve the trend of gains of inductance and quality factor of on-chip inductors. By integrating the prepared ferrite magnetic nanomaterial to the on-chip inductors with different structures, the measurement performances show an obvious improvement even in GHz frequency range. In addition, the studies of CMOS compatible process to integrate the nanomaterial promote the widespread application of magnetic nanomaterial in RF on-chip inductors.

  3. Computer System Design System-on-Chip

    CERN Document Server

    Flynn, Michael J

    2011-01-01

    The next generation of computer system designers will be less concerned about details of processors and memories, and more concerned about the elements of a system tailored to particular applications. These designers will have a fundamental knowledge of processors and other elements in the system, but the success of their design will depend on the skills in making system-level tradeoffs that optimize the cost, performance and other attributes to meet application requirements. This book provides a new treatment of computer system design, particularly for System-on-Chip (SOC), which addresses th

  4. Stimulation of Dorsolateral Prefrontal Cortex Enhances Adaptive Cognitive Control: A High-Definition Transcranial Direct Current Stimulation Study.

    Science.gov (United States)

    Gbadeyan, Oyetunde; McMahon, Katie; Steinhauser, Marco; Meinzer, Marcus

    2016-12-14

    Conflict adaptation is a hallmark effect of adaptive cognitive control and refers to the adjustment of control to the level of previously experienced conflict. Conflict monitoring theory assumes that the dorsolateral prefrontal cortex (DLPFC) is causally involved in this adjustment. However, to date, evidence in humans is predominantly correlational, and heterogeneous with respect to the lateralization of control in the DLPFC. We used high-definition transcranial direct current stimulation (HD-tDCS), which allows for more focal current delivery than conventional tDCS, to clarify the causal involvement of the DLPFC in conflict adaptation. Specifically, we investigated the regional specificity and lateralization of potential beneficial stimulation effects on conflict adaptation during a visual flanker task. One hundred twenty healthy participants were assigned to four HD-tDCS conditions: left or right DLPFC or left or right primary motor cortex (M1). Each group underwent both active and sham HD-tDCS in crossover, double-blind designs. We obtained a sizeable conflict adaptation effect (measured as the modulation of the flanker effect as a function of previous response conflict) in all groups and conditions. However, this effect was larger under active HD-tDCS than under sham stimulation in both DLPFC groups. In contrast, active stimulation had no effect on conflict adaptation in the M1 groups. In sum, the present results indicate that the DLPFC plays a causal role in adaptive cognitive control, but that the involvement of DLPFC in control is not restricted to the left or right hemisphere. Moreover, our study confirms the potential of HD-tDCS to modulate cognition in a regionally specific manner.

  5. [Control of blood flow in nasal mucosa by electro-stimulation of sphenopalatine ganglion].

    Science.gov (United States)

    Zheng, C; Wang, Z

    1997-06-01

    The effects of control of blood flow on cat nasal mucosa by stimulating sphenopalatine ganglion (SPG) were studied using laser Doppler flowmetry in order to investigate the role of SPG. The study showed that the stimulation on one side of SPG could induce vasodilation, with increased blood flow, as well as protective reflexes on both sides. The reactivity depended on the stimulation intensity, frequency and duration. The stimulation on one side of postganglionic parasympathetic nerves, in which the stellate ganglion was resected, caused vasodilation only ipsilaterally. The results indicated that the vasodilation induced by stimulating SPG might be mediated via central reflex arc. The "reverse blood regulation" phenomenon was observed during stimulation of SPG as well. The mechanisms of "reverse blood regulation" induced by stimulating SPG need further investigation.

  6. Nanotechnology and the Developing World: Lab-on-Chip Technology for Health and Environmental Applications

    Science.gov (United States)

    Mehta, Michael D.

    2008-01-01

    This article argues that advances in nanotechnology in general, and lab-on-chip technology in particular, have the potential to benefit the developing world in its quest to control risks to human health and the environment. Based on the "risk society" thesis of Ulrich Beck, it is argued that the developed world must realign its science and…

  7. On-chip tunable long-period gratings in liquid crystal infiltrated photonic crystal fibers

    DEFF Research Database (Denmark)

    Wei, Lei; Weirich, Johannes; Alkeskjold, Thomas Tanggaard;

    2009-01-01

    An on-chip tunable long-period grating device in a liquid crystal infiltrated photonic crystal fiber is experimentally demonstrated. The depth and position of the notch are tuned electrically and thermally. The transmission axis can be electrically controlled as well as switched on and off....

  8. Nanotechnology and the Developing World: Lab-on-Chip Technology for Health and Environmental Applications

    Science.gov (United States)

    Mehta, Michael D.

    2008-01-01

    This article argues that advances in nanotechnology in general, and lab-on-chip technology in particular, have the potential to benefit the developing world in its quest to control risks to human health and the environment. Based on the "risk society" thesis of Ulrich Beck, it is argued that the developed world must realign its science and…

  9. Controlled Pseudopod Extension of Human Neutrophils Stimulated with Different Chemoattractants

    OpenAIRE

    Zhelev, Doncho V.; Alteraifi, Abdullatif M.; Chodniewicz, David

    2004-01-01

    The formation of pseudopods and lamellae after ligation of chemoattractant sensitive G-protein coupled receptors (GPCRs) is essential for chemotaxis. Here, pseudopod extension was stimulated with chemoattractant delivered from a micropipet. The chemoattractant diffusion and convection mass transport were considered, and it is shown that when the delivery of chemoattractant was limited by diffusion there was a strong chemoattractant gradient along the cell surface. The diffusion-limited delive...

  10. Encode the "STOP" command by photo-stimulation for precise control of rat-robot.

    Science.gov (United States)

    Chen, Sicong; Qu, Yi; Guo, Songchao; Shi, Zhaoyue; Xu, Kedi; Zheng, Xiaoxiang

    2013-01-01

    Studies on behavior control are important for bio-robots designation. For auto or manual navigation of the bio-robots, the accuracy of the command execution is especially critical. In this paper, we reported a precise "STOP" command for the rat-robots by optical stimulation of the central nervous system (CNS). We labeled dorsolateral periaqueductal gray (dlPAG) neurons with light sensitive channelrhodopsin-2 (ChR2) and directly probed the optical fiber to reactivate these neurons. The rats showed freezing behavior only upon the optical stimulation with an appropriate range of laser intensity and stimulation frequency. Neuron spikes and local field potential (LFP) were simultaneously recorded with optical stimulation by optrodes on free moving rat-robots. Together, our findings demonstrated the utility of deep brain optical stimulation for the stopping behavior of rat-robot control and indicated a potential application of optogenetics for precise control of bio-robots in further work.

  11. Optogenetics Based Rat-Robot Control: Optical Stimulation Encodes "Stop" and "Escape" Commands.

    Science.gov (United States)

    Chen, SiCong; Zhou, Hong; Guo, SongChao; Zhang, JiaCheng; Qu, Yi; Feng, ZhouYan; Xu, KeDi; Zheng, XiaoXiang

    2015-08-01

    Electric brain stimulation is frequently used in bio-robot control. However, one possible limitation of electric stimulation is the resultant wide range of influences that may lead to unexpected side-effects. Although there has been prior research done towards optogenetics based brain activation, there has not been much development regarding the comparisons between electric and optical methods of brain activation. In this study, we first encode "Stop" and "Escape" commands by optical stimulation in the dorsal periaqueductal grey (dPAG). The rats behavioral comparisons are then noted down under these two methods. The dPAG neural activity recorded during optical stimulation suggests rate and temporal coding mechanisms in behavioral control. The behavioral comparisons show that rats exhibit anxiety under the "Stop" command conveyed through both optical and electric methods. However, rats are able to recover more quickly from freezing only under optical "Stop" command. Under "Escape" commands, also conveyed through optical means, the rat would move with lessened urgency but the results are more stable. Moreover, c-Fos study shows the optical stimulation activates restricted range in midbrain: the optical stimulation affected only dPAG and its downstreams but electric stimulation activates both the upstream and downstream circuits, in which the glutamatergic neurons are largely occupied and play important role in "Stop" and "Escape" behavior controls. We conclude that optical stimulation is more suited for encoding "Stop" and "Escape" commands for rat-robot control.

  12. Frequency domain processing of on-chip biphoton frequency comb

    CERN Document Server

    Jaramillo-Villegas, Jose A; Odele, Ogaga D; Leaird, Daniel E; Ou, Zhe-Yu; Qi, Minghao; Weiner, Andrew M

    2016-01-01

    Quantum information processing (QIP) promises to improve the security of our communications as well as to solve some algorithms with exponential complexity in polynomial time. Biphotons have been demonstrated as one of the most promising platforms for real implementations of QIP systems. In particular, time-bin entangled photons have been used for implementations of quantum gates which require highly stable interferometers. On the other hand, frequency-bin entanglement has been proposed to avoid the use of interferometers and the complexity of their stabilization, which potentially makes the implementation of quantum gates highly scalable. Through Fourier transform pulse shaping and electro-optic modulation, there has been a wide range of experiments that show control of entangled photons in the frequency domain. In addition, biphoton frequency combs (BFC) have also been generated using bulk optics and frequency filtering of broadband continuous biphoton spectra. However, on-chip entangled photon pair generat...

  13. Near-Field, On-Chip Optical Brownian Ratchets.

    Science.gov (United States)

    Wu, Shao-Hua; Huang, Ningfeng; Jaquay, Eric; Povinelli, Michelle L

    2016-08-10

    Nanoparticles in aqueous solution are subject to collisions with solvent molecules, resulting in random, Brownian motion. By breaking the spatiotemporal symmetry of the system, the motion can be rectified. In nature, Brownian ratchets leverage thermal fluctuations to provide directional motion of proteins and enzymes. In man-made systems, Brownian ratchets have been used for nanoparticle sorting and manipulation. Implementations based on optical traps provide a high degree of tunability along with precise spatiotemporal control. Here, we demonstrate an optical Brownian ratchet based on the near-field traps of an asymmetrically patterned photonic crystal. The system yields over 25 times greater trap stiffness than conventional optical tweezers. Our technique opens up new possibilities for particle manipulation in a microfluidic, lab-on-chip environment.

  14. High Speed Global On-Chip Interconnects and Transceivers

    NARCIS (Netherlands)

    Mensink, E.

    2007-01-01

    The data rate of global on-chip interconnects (up to 10 mm) is limited by a large distributed resistance and capacitance. This thesis describes methods to increase the achievable data rate of global on-chip interconnects with minimal chip area and power consumption, while maintaining data integrity.

  15. Interconnects and On-Chip Data Communication Techniques

    NARCIS (Netherlands)

    Mensink, E.; Schinkel, Daniel; Klumperink, Eric A.M.; van Tuijl, Adrianus Johannes Maria

    Global on-chip communication is rapidly becoming a speed and power bottleneck in CMOS circuits. In this paper, a ‘mixed-signal’ approach is taken to analyze on-chip interconnects and it is investigated how data-rates can be improved. It is shown that complex signaling schemes such as OFDM and CDMA

  16. Thermal Management for Dependable On-Chip Systems

    OpenAIRE

    Ebi, Thomas

    2014-01-01

    This thesis addresses the dependability issues in on-chip systems from a thermal perspective. This includes an explanation and analysis of models to show the relationship between dependability and tempature. Additionally, multiple novel methods for on-chip thermal management are introduced aiming to optimize thermal properties. Analysis of the methods is done through simulation and through infrared thermal camera measurements.

  17. The ReNoC Reconfigurable Network-on-Chip

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Stensgaard, Mikkel Bystrup; Sparsø, Jens

    2011-01-01

    This article presents a reconfigurable network-on-chip architecture called ReNoC, which is intended for use in general-purpose multiprocessor system-on-chip platforms, and which enables application-specific logical NoC topologies to be configured, thus providing both efficiency and flexibility...

  18. Energy Model of Networks-on-Chip and a Bus

    NARCIS (Netherlands)

    Wolkotte, P.T.; Smit, Gerardus Johannes Maria; Kavaldjiev, N.K.; Becker, Jens E.; Becker, Jürgen; Nurmi, J.; Takala, J.; Hamalainen, T.D.

    2005-01-01

    A Network-on-Chip (NoC) is an energy-efficient onchip communication architecture for Multi-Processor Systemon-Chip (MPSoC) architectures. In earlier papers we proposed two Network-on-Chip architectures based on packet-switching and circuit-switching. In this paper we derive an energy model for both

  19. Closed-loop control of spinal cord stimulation to restore hand function after paralysis

    Directory of Open Access Journals (Sweden)

    Jonas B Zimmermann

    2014-05-01

    Full Text Available As yet, no cure exists for upper-limb paralysis resulting from the damage to motor pathways after spinal cord injury or stroke. Recently, neural activity from the motor cortex of paralyzed individuals has been used to control the movements of a robot arm but restoring function to patients’ actual limbs remains a considerable challenge. Previously we have shown that electrical stimulation of the cervical spinal cord in anesthetized monkeys can elicit functional upper-limb movements like reaching and grasping. Here we show that stimulation can be controlled using cortical activity in awake animals to bypass disruption of the corticospinal system, restoring their ability to perform a simple upper-limb task. Monkeys were trained to grasp and pull a spring-loaded handle. After temporary paralysis of the hand was induced by reversible inactivation of primary motor cortex using muscimol, grasp-related single-unit activity from the ventral premotor cortex was converted into stimulation patterns delivered in real-time to the cervical spinal grey matter. During periods of closed-loop stimulation, task-modulated electromyogram, movement amplitude and task success rate were improved relative to interleaved control periods without stimulation. In some sessions, single motor unit activity from weakly active muscles was also used successfully to control stimulation. These results are the first use of a neural prosthesis to improve the hand function of primates after motor cortex disruption, and demonstrate the potential for closed-loop cortical control of spinal cord stimulation to reanimate paralyzed limbs.

  20. Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study

    DEFF Research Database (Denmark)

    Jønsson, Iben; Hagstrøm, Søren; Siggaard, Charlotte

    Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study......Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study...

  1. Transcranial direct current stimulation improves seizure control in patients with Rasmussen encephalitis.

    Science.gov (United States)

    Tekturk, Pinar; Erdogan, Ezgi Tuna; Kurt, Adnan; Kocagoncu, Ece; Kucuk, Zeynep; Kinay, Demet; Yapici, Zuhal; Aksu, Serkan; Baykan, Betul; Karamursel, Sacit

    2016-03-01

    Rasmussen encephalitis is associated with severe seizures that are unresponsive to antiepileptic drugs, as well as immunosuppressants. Transcranial direct current stimulation (t-DCS) is a non-invasive and safe method tried mostly for focal epilepsies with different aetiologies. To date, there is only one published study with two case reports describing the effect of t-DCS in Rasmussen encephalitis. Our aim was to investigate the effect of t-DCS on seizures in Rasmussen encephalitis and to clarify its safety. Five patients (mean age: 19; three females), diagnosed with Rasmussen encephalitis were included in this study. Patients received first cathodal, then anodal (2 mA for 30 minutes on three consecutive days for non-sham stimulations), and finally sham stimulation with two-month intervals, respectively. Three patients received classic (DC) cathodal t-DCS whereas two patients received cathodal stimulation with amplitude modulation at 12 Hz. Afterwards, all patients received anodal stimulation with amplitude modulation at 12 Hz. In the last part of the trial, sham stimulation (a 60-second stimulation with gradually decreasing amplitude to zero in the last 15 seconds) was applied to three patients. Maximum current density was 571 mA/m2 using 70 mm x 50 mm wet sponge electrodes with 2-mA maximum, current controlled stimulator, and maximum charge density was 1028 C/m2 for a 30-minute stimulation period. After cathodal stimulation, all but one patient had a greater than 50% decrease in seizure frequency. Two patients who received modulated cathodal t-DCS had better results. The longest positive effect lasted for one month. A second trial with modulated anodal stimulation and a third with sham stimulation were not effective. No adverse effect was reported with all types of stimulations. Both classic and modulated cathodal t-DCS may be suitable alternative methods for improving seizure outcome in Rasmussen encephalitis patients.

  2. Real-time control of stepper motors for mechano-sensory stimulation.

    Science.gov (United States)

    Muñiz, Carlos; Levi, Rafael; Benkrid, Meriem; Rodríguez, Francisco B; Varona, Pablo

    2008-07-15

    Mechanical stimulation is widely used to study sensory encoding in the nervous system of living organisms. The stimulation of mechano-receptor neurons is achieved through a large variety of devices that generate movement or vibration. In many situations, a hard real-time (RT) control of the device (in the millisecond time scale) is needed to produce realistic mechanical stimuli. The real-time control can be required to achieve the desired precision in the device or to implement activity-dependent stimulation protocols that imply the detection of physiological events to drive the stimulus in real time. In this paper we show that real-time software technology can be used to control stepper motors for mechano-receptor stimulation, and to implement artificial closed-loops to address the sensory-motor transformation. We illustrate this using as an example the control of a stepper motor to precisely move gravimetric organs in in vitro preparations.

  3. On-Chip Bondwire Magnetics with Ferrite-Epoxy Glob Coating for Power Systems on Chip

    Directory of Open Access Journals (Sweden)

    Jian Lu

    2008-01-01

    Full Text Available A novel concept of on-chip bondwire inductors and transformers with ferrite epoxy glob coating is proposed to offer a cost effective approach realizing power systems on chip (SOC. We have investigated the concept both experimentally and with finite element modeling. A Q factor of 30–40 is experimentally demonstrated for the bondwire inductors which represents an improvement by a factor of 3–30 over the state-of-the-art MEMS micromachined inductors. Transformer parameters including self- and mutual inductance and coupling factors are extracted from both modeled and measured S-parameters. More importantly, the bondwire magnetic components can be easily integrated into SOC manufacturing processes with minimal changes and open enormous possibilities for realizing cost-effective, high-current, high-efficiency power SOCs.

  4. Posture-dependent control of stimulation in standing neuroprosthesis: Simulation feasibility study

    OpenAIRE

    Musa L. Audu, PhD; Steven J. Gartman, MS; Raviraj Nataraj, PhD; Ronald J. Triolo, PhD

    2014-01-01

    We used a three-dimensional biomechanical model of human standing to test the feasibility of feed-forward control systems that vary stimulation to paralyzed muscles based on the user’s posture and desire to effect a postural change. The controllers examined were (1) constant baseline stimulation, which represented muscle activation required to maintain erect standing, and (2) posture follower, which varied muscle activation as a function of the location of the projection of whole-body center ...

  5. Design of Networks-on-Chip for Real-Time Multi-Processor Systems-on-Chip

    DEFF Research Database (Denmark)

    Sparsø, Jens

    2012-01-01

    This paper addresses the design of networks-on-chips for use in multi-processor systems-on-chips - the hardware platforms used in embedded systems. These platforms typically have to guarantee real-time properties, and as the network is a shared resource, it has to provide service guarantees...

  6. An integrated lab-on-chip for rapid identification and simultaneous differentiation of tropical pathogens.

    Science.gov (United States)

    Tan, Jeslin J L; Capozzoli, Monica; Sato, Mitsuharu; Watthanaworawit, Wanitda; Ling, Clare L; Mauduit, Marjorie; Malleret, Benoît; Grüner, Anne-Charlotte; Tan, Rosemary; Nosten, François H; Snounou, Georges; Rénia, Laurent; Ng, Lisa F P

    2014-01-01

    Tropical pathogens often cause febrile illnesses in humans and are responsible for considerable morbidity and mortality. The similarities in clinical symptoms provoked by these pathogens make diagnosis difficult. Thus, early, rapid and accurate diagnosis will be crucial in patient management and in the control of these diseases. In this study, a microfluidic lab-on-chip integrating multiplex molecular amplification and DNA microarray hybridization was developed for simultaneous detection and species differentiation of 26 globally important tropical pathogens. The analytical performance of the lab-on-chip for each pathogen ranged from 102 to 103 DNA or RNA copies. Assay performance was further verified with human whole blood spiked with Plasmodium falciparum and Chikungunya virus that yielded a range of detection from 200 to 4×105 parasites, and from 250 to 4×107 PFU respectively. This lab-on-chip was subsequently assessed and evaluated using 170 retrospective patient specimens in Singapore and Thailand. The lab-on-chip had a detection sensitivity of 83.1% and a specificity of 100% for P. falciparum; a sensitivity of 91.3% and a specificity of 99.3% for P. vivax; a positive 90.0% agreement and a specificity of 100% for Chikungunya virus; and a positive 85.0% agreement and a specificity of 100% for Dengue virus serotype 3 with reference methods conducted on the samples. Results suggested the practicality of an amplification microarray-based approach in a field setting for high-throughput detection and identification of tropical pathogens.

  7. Overview of status and challenges of system testing on chip with embedded DRAMS

    Science.gov (United States)

    Falter, T.; Richter, D.

    2000-05-01

    The combination of logic together with DRAM as a system on chip (SOC) has many advantages for a large variety of computing and network applications. The goal of testing a system is to detect the fabrication caused faults in order to guarantee the defined quality. The increasing size of memories, shrinking dimensions, higher demands on application (frequency and temperature range) and quality cause new problems and higher costs of testing. On the other hand the pressure to serve the market with low cost products forces the test engineer to reduce test costs by reducing test times and using low cost test equipment. Different solutions are discussed in this paper in order to meet these challenges. The variety of test approaches for testing SOC with embedded DRAMs reaches from testing with completely chip external test logic, a simple on-chip test logic up to a full blown built-in self test (BIST) on chip. Which choice is the right one depends on different criteria e.g. memory size, quality demands and application of the product. As an example the modular embedded DRAM core concept from Infineon Technologies is discussed, which includes a dedicated modular test concept based on on-chip integration of a test controller.

  8. On-chip single photon filtering and multiplexing in hybrid quantum photonic circuits.

    Science.gov (United States)

    Elshaari, Ali W; Zadeh, Iman Esmaeil; Fognini, Andreas; Reimer, Michael E; Dalacu, Dan; Poole, Philip J; Zwiller, Val; Jöns, Klaus D

    2017-08-30

    Quantum light plays a pivotal role in modern science and future photonic applications. Since the advent of integrated quantum nanophotonics different material platforms based on III-V nanostructures-, colour centers-, and nonlinear waveguides as on-chip light sources have been investigated. Each platform has unique advantages and limitations; however, all implementations face major challenges with filtering of individual quantum states, scalable integration, deterministic multiplexing of selected quantum emitters, and on-chip excitation suppression. Here we overcome all of these challenges with a hybrid and scalable approach, where single III-V quantum emitters are positioned and deterministically integrated in a complementary metal-oxide-semiconductor-compatible photonic circuit. We demonstrate reconfigurable on-chip single-photon filtering and wavelength division multiplexing with a foot print one million times smaller than similar table-top approaches, while offering excitation suppression of more than 95 dB and efficient routing of single photons over a bandwidth of 40 nm. Our work marks an important step to harvest quantum optical technologies' full potential.Combining different integration platforms on the same chip is currently one of the main challenges for quantum technologies. Here, Elshaari et al. show III-V Quantum Dots embedded in nanowires operating in a CMOS compatible circuit, with controlled on-chip filtering and tunable routing.

  9. Silicon Nanophotonics for Many-Core On-Chip Networks

    Science.gov (United States)

    Mohamed, Moustafa

    Number of cores in many-core architectures are scaling to unprecedented levels requiring ever increasing communication capacity. Traditionally, architects follow the path of higher throughput at the expense of latency. This trend has evolved into being problematic for performance in many-core architectures. Moreover, the trends of power consumption is increasing with system scaling mandating nontraditional solutions. Nanophotonics can address these problems, offering benefits in the three frontiers of many-core processor design: Latency, bandwidth, and power. Nanophotonics leverage circuit-switching flow control allowing low latency; in addition, the power consumption of optical links is significantly lower compared to their electrical counterparts at intermediate and long links. Finally, through wave division multiplexing, we can keep the high bandwidth trends without sacrificing the throughput. This thesis focuses on realizing nanophotonics for communication in many-core architectures at different design levels considering reliability challenges that our fabrication and measurements reveal. First, we study how to design on-chip networks for low latency, low power, and high bandwidth by exploiting the full potential of nanophotonics. The design process considers device level limitations and capabilities on one hand, and system level demands in terms of power and performance on the other hand. The design involves the choice of devices, designing the optical link, the topology, the arbitration technique, and the routing mechanism. Next, we address the problem of reliability in on-chip networks. Reliability not only degrades performance but can block communication. Hence, we propose a reliability-aware design flow and present a reliability management technique based on this flow to address reliability in the system. In the proposed flow reliability is modeled and analyzed for at the device, architecture, and system level. Our reliability management technique is

  10. Acupoints Stimulation for Anxiety and Depression in Cancer Patients: A Quantitative Synthesis of Randomized Controlled Trials.

    Science.gov (United States)

    Wang, Tao; Deng, Renli; Tan, Jing-Yu; Guan, Feng-Guang

    2016-01-01

    This study aims at concluding the current evidence on the therapeutic effects of acupoints stimulation for cancer patients with anxiety and depression. Randomized controlled trials using acupoints stimulation for relieving anxiety and/or depression in cancer patients were searched, and 11 studies were finally included, of which eight trials compared acupoints stimulation with standard methods of treatment/care, and acupoints stimulation showed significantly better effects in improving depression than using standard methods of treatment/care. Four studies compared true acupoints stimulation with sham methods, and no significant differences can be found between groups for either depression or anxiety, although the pooled effects still favored true intervention. For the five studies that evaluated sleep quality, the results were conflicting, with three supporting the superiority of acupoints stimulation in improving sleep quality and two demonstrating no differences across groups. Acupoints stimulation seems to be an effective approach in relieving depression and anxiety in cancer patients, and placebo effects may partially contribute to the benefits. However, the evidence is not conclusive due to the limited number of included studies and the clinical heterogeneity identified among trials. More rigorous designed randomized, sham-controlled studies are necessary in future research.

  11. Acupoints Stimulation for Anxiety and Depression in Cancer Patients: A Quantitative Synthesis of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2016-01-01

    Full Text Available This study aims at concluding the current evidence on the therapeutic effects of acupoints stimulation for cancer patients with anxiety and depression. Randomized controlled trials using acupoints stimulation for relieving anxiety and/or depression in cancer patients were searched, and 11 studies were finally included, of which eight trials compared acupoints stimulation with standard methods of treatment/care, and acupoints stimulation showed significantly better effects in improving depression than using standard methods of treatment/care. Four studies compared true acupoints stimulation with sham methods, and no significant differences can be found between groups for either depression or anxiety, although the pooled effects still favored true intervention. For the five studies that evaluated sleep quality, the results were conflicting, with three supporting the superiority of acupoints stimulation in improving sleep quality and two demonstrating no differences across groups. Acupoints stimulation seems to be an effective approach in relieving depression and anxiety in cancer patients, and placebo effects may partially contribute to the benefits. However, the evidence is not conclusive due to the limited number of included studies and the clinical heterogeneity identified among trials. More rigorous designed randomized, sham-controlled studies are necessary in future research.

  12. TRANSCUTANEOUS ELECTRICAL NERVE-STIMULATION FOR THE CONTROL OF PAIN

    NARCIS (Netherlands)

    TENVAARWERK, IAM; MEYLER, WJ; DEJONGSTE, MJL

    1995-01-01

    In this review article the neurophysiological mechanisms through which the effect of TENS can be explained will be discussed. The clinical studies on the effectiveness of TENS for the control of pain, both in the acute and chronic state, are summarized, including contradictory findings, mainly due t

  13. Myoelectric Signals from Paretic Wrist Extensor Controlling Electrical Stimulation of the Same Muscle

    DEFF Research Database (Denmark)

    Rune, Thorsen; Fin, Biering-Sørensen; Hansen, Steffen Duus

    1996-01-01

    A device for enhancement of the grip in C5/6 spinal cord lesioned tetraplegics is under development. It uses the myoelectric signal from the paretic wrist extensor for control of electrical stimulation of the same muscle. The tetraplegics shall with the device be able to obtain a passive grip...... between the thumb an the index finger by extension of the wrist. Surface electrodes are used for myoelectric recording and stimulation. Main problems are filtering of the recorded signal and stimulation. Solutions to these problems are addressed and discussed....

  14. Application of non-linear control theory to a model of deep brain stimulation.

    Science.gov (United States)

    Davidson, Clare M; Lowery, Madeleine M; de Paor, Annraoi M

    2011-01-01

    Deep brain stimulation (DBS) effectively alleviates the pathological neural activity associated with Parkinson's disease. Its exact mode of action is not entirely understood. This paper explores theoretically the optimum stimulation parameters necessary to quench oscillations in a neural-mass type model with second order dynamics. This model applies well established nonlinear control system theory to DBS. The analysis here determines the minimum criteria in terms of amplitude and pulse duration of stimulation, necessary to quench the unwanted oscillations in a closed loop system, and outlines the relationship between this model and the actual physiological system.

  15. Classical and adaptive control of ex vivo skeletal muscle contractions using Functional Electrical Stimulation (FES)

    Science.gov (United States)

    Shoemaker, Adam; Grange, Robert W.; Abaid, Nicole; Leonessa, Alexander

    2017-01-01

    Functional Electrical Stimulation is a promising approach to treat patients by stimulating the peripheral nerves and their corresponding motor neurons using electrical current. This technique helps maintain muscle mass and promote blood flow in the absence of a functioning nervous system. The goal of this work is to control muscle contractions from FES via three different algorithms and assess the most appropriate controller providing effective stimulation of the muscle. An open-loop system and a closed-loop system with three types of model-free feedback controllers were assessed for tracking control of skeletal muscle contractions: a Proportional-Integral (PI) controller, a Model Reference Adaptive Control algorithm, and an Adaptive Augmented PI system. Furthermore, a mathematical model of a muscle-mass-spring system was implemented in simulation to test the open-loop case and closed-loop controllers. These simulations were carried out and then validated through experiments ex vivo. The experiments included muscle contractions following four distinct trajectories: a step, sine, ramp, and square wave. Overall, the closed-loop controllers followed the stimulation trajectories set for all the simulated and tested muscles. When comparing the experimental outcomes of each controller, we concluded that the Adaptive Augmented PI algorithm provided the best closed-loop performance for speed of convergence and disturbance rejection. PMID:28273101

  16. Closed-Loop Control for Squeeze Film Effect in Tactile Stimulator

    OpenAIRE

    Ben Messaoud, Wael; Lemaire-Semail, Betty; Bueno, Marie-Ange; Amberg, Michel; Giraud, Frédéric

    2014-01-01

    International audience; This paper presents a method for controlling the vibration amplitude of a tactile stimulator used to give the sensation to the fingertip that it touches a texture. The active surface of the stimulator is excited by an ultrasonic vibration frequency in order to modulate the friction coefficient with the fingertip. Due to the large size of the tactile display, two types of perturbations may affect the vibration amplitude which are the finger pressure and the temperature ...

  17. Biosensors-on-chip: a topical review

    Science.gov (United States)

    Chen, Sensen; Shamsi, Mohtashim H.

    2017-08-01

    This review will examine the integration of two fields that are currently at the forefront of science, i.e. biosensors and microfluidics. As a lab-on-a-chip (LOC) technology, microfluidics has been enriched by the integration of various detection tools for analyte detection and quantitation. The application of such microfluidic platforms is greatly increased in the area of biosensors geared towards point-of-care diagnostics. Together, the merger of microfluidics and biosensors has generated miniaturized devices for sample processing and sensitive detection with quantitation. We believe that microfluidic biosensors (biosensors-on-chip) are essential for developing robust and cost effective point-of-care diagnostics. This review is relevant to a variety of disciplines, such as medical science, clinical diagnostics, LOC technologies including MEMs/NEMs, and analytical science. Specifically, this review will appeal to scientists working in the two overlapping fields of biosensors and microfluidics, and will also help new scientists to find their directions in developing point-of-care devices.

  18. On-Chip Diamond Raman Laser

    CERN Document Server

    Latawiec, Pawel; Burek, Michael J; Hausmann, Birgit J M; Bulu, Irfan; Loncar, Marko

    2015-01-01

    Synthetic single-crystal diamond has recently emerged as a promising platform for Raman lasers at exotic wavelengths due to its giant Raman shift, large transparency window and excellent thermal properties yielding a greatly enhanced figure-of-merit compared to conventional materials. To date, diamond Raman lasers have been realized using bulk plates placed inside macroscopic cavities, requiring careful alignment and resulting in high threshold powers (~W-kW). Here we demonstrate an on-chip Raman laser based on fully-integrated, high quality-factor, diamond racetrack micro-resonators embedded in silica. Pumping at telecom wavelengths, we show Stokes output discretely tunable over a ~100nm bandwidth around 2-{\\mu}m with output powers >250 {\\mu}W, extending the functionality of diamond Raman lasers to an interesting wavelength range at the edge of the mid-infrared spectrum. Continuous-wave operation with only ~85 mW pump threshold power in the feeding waveguide is demonstrated along with continuous, mode-hop-fr...

  19. On-chip pretreatment of whole blood by using MEMS technology

    CERN Document Server

    Chen, Xing

    2012-01-01

    Microfabrication technology has stimulated a plurality of lab-on-a-chip research and development efforts aimed at enabling biomedical researchers and health care practitioners to manipulate and analyze complex biological fluids at the nano and microliter scale. On-chip pretreatment of whole blood is one of the hottest topics in lab-on-a-chip research since whole blood has been regarded as the most important clinical sample. Various microfluidic chips for blood sample pretreatment, such as plasma isolation, cells separation, cells lysis, gene or protein purification, etc., are described in this

  20. Control of thumb force using surface functional electrical stimulation and muscle load sharing

    NARCIS (Netherlands)

    Westerveld, A.J.; Schouten, A.C.; Veltink, P.H.; Van der Kooij, H.

    2013-01-01

    Background Stroke survivors often have difficulties in manipulating objects with their affected hand. Thumb control plays an important role in object manipulation. Surface functional electrical stimulation (FES) can assist movement. We aim to control the 2D thumb force by predicting the sum of indiv

  1. Subthalamic Nucleus Deep Brain Stimulation Changes Velopharyngeal Control in Parkinson's Disease

    Science.gov (United States)

    Hammer, Michael J.; Barlow, Steven M.; Lyons, Kelly E.; Pahwa, Rajesh

    2011-01-01

    Purpose: Adequate velopharyngeal control is essential for speech, but may be impaired in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on velopharyngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of velopharyngeal…

  2. Control of thumb force using surface functional electrical stimulation and muscle load sharing

    NARCIS (Netherlands)

    Westerveld, Ard; Westerveld, Ard J.; Schouten, Alfred Christiaan; Veltink, Petrus H.; van der Kooij, Herman

    2013-01-01

    Background: Stroke survivors often have difficulties in manipulating objects with their affected hand. Thumb control plays an important role in object manipulation. Surface functional electrical stimulation (FES) can assist movement. We aim to control the 2D thumb force by predicting the sum of

  3. Control of thumb force using surface functional electrical stimulation and muscle load sharing

    NARCIS (Netherlands)

    Westerveld, A.J.; Schouten, A.C.; Veltink, P.H.; Van der Kooij, H.

    2013-01-01

    Background Stroke survivors often have difficulties in manipulating objects with their affected hand. Thumb control plays an important role in object manipulation. Surface functional electrical stimulation (FES) can assist movement. We aim to control the 2D thumb force by predicting the sum of

  4. Network-on-chip the next generation of system-on-chip integration

    CERN Document Server

    Kundu, Santanu

    2014-01-01

    ""What makes this book special as compared to the current literature in the field is that it provides a complete picture of NoC architectures. In fact, current books in the context of NoCs are usually specific and presuppose a basic knowledge of NoC architectures. Conversely, this book provides a complete guide for both unskilled readers and researchers working in the area, to acquire not only the basic concepts but also the advanced techniques for improving power, cost and performance metrics of the on-chip communication system.""-Maurizio Palesi, Kore University, Italy.

  5. Stimulating productivity of hydroponic lettuce in controlled environments with triacontanol

    Science.gov (United States)

    Knight, S. L.; Mitchell, C. A.

    1987-01-01

    Triacontanol (1-triacontanol) applied as a foliar spray at 10(-7) M to 4-day-old, hydroponically grown leaf lettuce (Lactuca sativa L.) seedlings in a controlled environment increased leaf fresh and dry weight 13% to 20% and root fresh and dry weight 13% to 24% 6 days after application, relative to plants sprayed with water. When applied at 8 as well as 4 days after seeding, triacontanol increased plant fresh and dry weight, leaf area, and mean relative growth rate 12% to 37%. There was no benefit of repeating application of triacontanol in terms of leaf dry weight gain.

  6. Low-Voltage Process-Compensated VCO with On-Chip Process Monitoring and Body-Biasing Circuit Techniques

    OpenAIRE

    Ueno, Ken; Hirose, Tetsuya; Asai, Tetsuya; Amemiya, Yoshihito

    2009-01-01

    A voltage-controlled oscillator (VCO) tolerant to process variations at lower supply voltage was proposed. The circuit consists of an on-chip threshold-voltage-monitoring circuit, a current-source circuit, a body-biasing control circuit, and the delay cells of the VCO. Because variations in low-voltage VCO frequency are mainly determined by that of the current in delay cells. a current-compensation technique was adopted by using an on-chip threshold-voltage-monitoring circuit and body-biasing...

  7. On-Chip Network Design Automation with Source Routing Switches

    Institute of Scientific and Technical Information of China (English)

    MA Liwei; SUN Yihe

    2007-01-01

    Network-on-chip (NoC) is a new design paradigm for system-on-chip intraconnections in the billion-transistor era. Application specific on-chip network design is essential for NoC success in this new era.This paper presents a class of source routing switch that can be used to efficiently form arbitrary network topologies and that can be optimized for various applications. Hardware description language versions of the networks can be generated automatically for simulations and for syntheses. A series of switches and networks has been configured with their performances including latency, delay, area, and power, and analyzed theoretically and experimentally. The results show that this NoC architecture provides a large design space for application specific on-chip network designs.

  8. Crosstalk in modern on-chip interconnects a FDTD approach

    CERN Document Server

    Kaushik, B K; Patnaik, Amalendu

    2016-01-01

    The book provides accurate FDTD models for on-chip interconnects, covering most recent advancements in materials and design. Furthermore, depending on the geometry and physical configurations, different electrical equivalent models for CNT and GNR based interconnects are presented. Based on the electrical equivalent models the performance comparison among the Cu, CNT and GNR-based interconnects are also discussed in the book. The proposed models are validated with the HSPICE simulations. The book introduces the current research scenario in the modeling of on-chip interconnects. It presents the structure, properties, and characteristics of graphene based on-chip interconnects and the FDTD modeling of Cu based on-chip interconnects. The model considers the non-linear effects of CMOS driver as well as the transmission line effects of interconnect line that includes coupling capacitance and mutual inductance effects. In a more realistic manner, the proposed model includes the effect of width-dependent MFP of the ...

  9. Reliability, Availability and Serviceability of Networks-on-Chip

    CERN Document Server

    Cota, Érika; Soares Lubaszewski, Marcelo

    2012-01-01

    This book presents an overview of the issues related to the test, diagnosis and fault-tolerance of Network on Chip-based systems. It is the first book dedicated to the quality aspects of NoC-based systems and will serve as an invaluable reference to the problems, challenges, solutions, and trade-offs related to designing and implementing state-of-the-art, on-chip communication architectures.

  10. Nanofluidic Lab-On-Chip Technology for DNA Identification

    Science.gov (United States)

    2013-09-30

    technical 3. DATES COVERED (From - To) May 2012 - Jun 2013 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Nanofluidic LaB-ON-Chip Technology for DNA...AVAILABILITY STATEMENT Publicly available. 3-0/ 3/Oo3o%J - 14. ABSTRACT In this project we have investigated the potential of nanofluidic lab-on...chip nanofluidic platforms may enable rapid and inexpensive, characterization and analysis of DNA biomarkers. Advantages include overall ease of

  11. Signal processing for on-chip space division multiplexing

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Ding, Yunhong; Xu, Jing;

    2015-01-01

    Our recent results on the demonstration of on-chip mode-division multiplexing are reviewed, with special emphasis on nonlinear all-optical signal processing. Mode-selective parametric processes are demonstrated in a silicon-on-insulator waveguide.......Our recent results on the demonstration of on-chip mode-division multiplexing are reviewed, with special emphasis on nonlinear all-optical signal processing. Mode-selective parametric processes are demonstrated in a silicon-on-insulator waveguide....

  12. Sequential and selective localized optical heating in water via on-chip dielectric nanopatterning.

    Science.gov (United States)

    Morsy, Ahmed M; Biswas, Roshni; Povinelli, Michelle L

    2017-07-24

    We study the use of nanopatterned silicon membranes to obtain optically-induced heating in water. We show that by varying the detuning between an absorptive optical resonance of the patterned membrane and an illumination laser, both the magnitude and response time of the temperature rise can be controlled. This allows for either sequential or selective heating of different patterned areas on chip. We obtain a steady-state temperature of approximately 100 °C for a 805.5nm CW laser power density of 66 µW/μm(2) and observe microbubble formation. The ability to spatially and temporally control temperature on the microscale should enable the study of heat-induced effects in a variety of chemical and biological lab-on-chip applications.

  13. On-chip steering of entangled photons in nonlinear photonic crystals.

    Science.gov (United States)

    Leng, H Y; Yu, X Q; Gong, Y X; Xu, P; Xie, Z D; Jin, H; Zhang, C; Zhu, S N

    2011-08-16

    One promising technique for working toward practical photonic quantum technologies is to implement multiple operations on a monolithic chip, thereby improving stability, scalability and miniaturization. The on-chip spatial control of entangled photons will certainly benefit numerous applications, including quantum imaging, quantum lithography, quantum metrology and quantum computation. However, external optical elements are usually required to spatially control the entangled photons. Here we present the first experimental demonstration of on-chip spatial control of entangled photons, based on a domain-engineered nonlinear photonic crystal. We manipulate the entangled photons using the inherent properties of the crystal during the parametric downconversion, demonstrating two-photon focusing and beam-splitting from a periodically poled lithium tantalate crystal with a parabolic phase profile. These experimental results indicate that versatile and precise spatial control of entangled photons is achievable. Because they may be operated independent of any bulk optical elements, domain-engineered nonlinear photonic crystals may prove to be a valuable ingredient in on-chip integrated quantum optics.

  14. Closed-Loop Control of Myoelectric Prostheses With Electrotactile Feedback: Influence of Stimulation Artifact and Blanking.

    Science.gov (United States)

    Hartmann, Cornelia; Dosen, Strahinja; Amsuess, Sebastian; Farina, Dario

    2015-09-01

    Electrocutaneous stimulation is a promising approach to provide sensory feedback to amputees, and thus close the loop in upper limb prosthetic systems. However, the stimulation introduces artifacts in the recorded electromyographic (EMG) signals, which may be detrimental for the control of myoelectric prostheses. In this study, artifact blanking with three data segmentation approaches was investigated as a simple method to restore the performance of pattern recognition in prosthesis control (eight motions) when EMG signals are corrupted by stimulation artifacts. The methods were tested over a range of stimulation conditions and using four feature sets, comprising both time and frequency domain features. The results demonstrated that when stimulation artifacts were present, the classification performance improved with blanking in all tested conditions. In some cases, the classification performance with blanking was at the level of the benchmark (artifact-free data). The greatest pulse duration and frequency that allowed a full performance recovery were 400 μs and 150 Hz, respectively. These results show that artifact blanking can be used as a practical solution to eliminate the negative influence of the stimulation artifact on EMG pattern classification in a broad range of conditions, thus allowing to close the loop in myoelectric prostheses using electrotactile feedback.

  15. Cognitive stimulation for dementia: a systematic review of the evidence of effectiveness from randomised controlled trials.

    Science.gov (United States)

    Aguirre, Elisa; Woods, Robert T; Spector, Aimee; Orrell, Martin

    2013-01-01

    Cognitive stimulation is a psychological intervention widely used in dementia care, which offers a range of activities for people with dementia and provides general stimulation of cognitive abilities. This systematic review evaluates the effectiveness of cognitive stimulation in dementia. The review included studies from the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group, called ALOIS. This yielded ninety-four studies, of which fifteen were randomised controlled trials meeting the inclusion criteria. The analysis included 718 subjects (407 receiving cognitive stimulation and 311 in control groups). Results were subjected to a meta-analysis. A consistent significant benefit to cognitive function was identified following treatment and the benefits appeared to be over and above any medication effects. This remained evident at follow-up up to three months after the end of treatment. In secondary analyses, with smaller total sample sizes, significant benefits were also noted for quality of life and well-being, and on staff ratings of communication and social interaction. No differences in relation to mood, activities of daily living or challenging behaviour were noted. There is consistent evidence that cognitive stimulation interventions benefit cognitive function and aspects of well-being. Cognitive stimulation should be made more widely available in dementia care.

  16. Integrated Millimeter-Wave Antennas for On-Chip Communication

    Directory of Open Access Journals (Sweden)

    S. Zainud-Deen

    2016-03-01

    Full Text Available This paper introduces the design and analysis of circularly polarized (CP and dual-polarized on-chip microstrip antennas for wireless communication at 60 GHz. The CP on-chip antenna consists of a circular aluminum patch with two overlapped circular slots fed by the transmission line. The radiation characteristics of the CP have been analyzed using the finite integration technique and finite element method based electromagnetic solvers. The CP antenna introduces left-hand circular polarization and employs as on-chip transmitter. A design of dual-polarized on-chip microstrip antenna at 60 GHz is investigated and is employed as on-chip receiver. The dual ports of the dual polarized antenna are designed with high isolation between them in order to be used as a two on-chip receivers. The radiation characteristics of the dual-port antenna have been calculated. The effect of the separation distance between the CP-antenna and the dual-polarized antenna on the same chip has been investigated. The performance parameters like the reflection coefficient, transmission coefficient, and the transmission gain of the two antennas at different separation distances have been introduced.

  17. Deep brain stimulation mechanisms: the control of network activity via neurochemistry modulation.

    Science.gov (United States)

    McIntyre, Cameron C; Anderson, Ross W

    2016-10-01

    Deep brain stimulation (DBS) has revolutionized the clinical care of late-stage Parkinson's disease and shows promise for improving the treatment of intractable neuropsychiatric disorders. However, after over 25 years of clinical experience, numerous questions still remain on the neurophysiological basis for the therapeutic mechanisms of action. At their fundamental core, the general purpose of electrical stimulation therapies in the nervous system are to use the applied electric field to manipulate the opening and closing of voltage-gated sodium channels on neurons, generate stimulation induced action potentials, and subsequently, control the release of neurotransmitters in targeted pathways. Historically, DBS mechanisms research has focused on characterizing the effects of stimulation on neurons and the resulting impact on neuronal network activity. However, when electrodes are placed within the central nervous system, glia are also being directly (and indirectly) influenced by the stimulation. Mounting evidence shows that non-neuronal tissue can play an important role in modulating the neurochemistry changes induced by DBS. The goal of this review is to evaluate how DBS effects on both neuronal and non-neuronal tissue can potentially work together to suppress oscillatory activity (and/or information transfer) between brain regions. These resulting effects of ~ 100 Hz electrical stimulation help explain how DBS can disrupt pathological network activity in the brain and generate therapeutic effects in patients. Deep brain stimulation is an effective clinical technology, but detailed therapeutic mechanisms remain undefined. This review provides an overview of the leading hypotheses, which focus on stimulation-induced disruption of network oscillations and integrates possible roles for non-neuronal tissue in explaining the clinical response to therapeutic stimulation. This article is part of a special issue on Parkinson disease.

  18. Microfluidics-Based Lab-on-Chip Systems in DNA-Based Biosensing: An Overview

    OpenAIRE

    Sabo Wada Dutse; Nor Azah Yusof

    2011-01-01

    Microfluidics-based lab-on-chip (LOC) systems are an active research area that is revolutionising high-throughput sequencing for the fast, sensitive and accurate detection of a variety of pathogens. LOCs also serve as portable diagnostic tools. The devices provide optimum control of nanolitre volumes of fluids and integrate various bioassay operations that allow the devices to rapidly sense pathogenic threat agents for environmental monitoring. LOC systems, such as microfluidic biochips, offe...

  19. Two-Dimensional Programmable Manipulation of Magnetic Nanoparticles on-Chip

    DEFF Research Database (Denmark)

    Sarella, Anandakumar; Torti, Andrea; Donolato, Marco

    2014-01-01

    A novel device is designed for on-chip selective trap and two-dimensional remote manipulation of single and multiple fluid-borne magnetic particles using field controlled magnetic domain walls in circular nanostructures. The combination of different ring-shaped nanostructures and field sequences...... allows for remote manipulation of magnetic particles with high-precision along any arbitrary pathway on a chip surface....

  20. Disturbance of contralateral unipedal postural control after stimulated and voluntary contractions of the ipsilateral limb.

    Science.gov (United States)

    Paillard, Thierry; Chaubet, Vincent; Maitre, Julien; Dumitrescu, Michel; Borel, Liliane

    2010-12-01

    One session of sustained unilateral voluntary muscular contractions increases central fatigue and induces a cross-over of fatigue of homologous contralateral muscles. It is not known, however, how this cross-transfer affects contralateral unipedal postural control. Moreover, contralateral neurophysiological effects differ between voluntary muscular contractions and electrically stimulated contractions. The aims of this study were thus to examine the effects of muscle fatigue on contralateral unipedal postural control and to compare the effects of stimulated and voluntary contractions. Fifteen subjects took part in the protocol. Fatigue of the ipsilateral quadriceps femoris was generated either by neuromuscular electrical stimulation (NMES) or by isometric voluntary muscular contraction (VOL). Postural control on the contralateral limb was measured before (PRE condition) and after the completion of the two fatiguing exercises (POST condition) using a force platform. We analyzed body sway area and the spectral power density given by the wavelet transform. In POST condition, postural control recorded in the unipedal stance on the contralateral limb was disturbed after NMES and VOL fatiguing exercises. In addition, postural control was similarly disturbed for both exercises. These results suggest that cross-over fatigue is able to disturb postural control after both stimulated and voluntary contractions.

  1. EFFECTIVENESS OF FUNCTIONAL MUSCLE STIMULATION IN IMPROVING MOTOR CONTROL AROUND SHOULDER IN PATIENTS WITH HEMIPLEGIA

    Directory of Open Access Journals (Sweden)

    Sirisha Nekkanti

    2015-02-01

    Full Text Available Background: The effect of electrical stimulation on motor outcomes around shoulder in acute hemiplegia is elusive. We tested the effect of stimulation of specific muscles around shoulder on motor outcome in shoulder in patient with hemiplegia. Methods: 32 first time hemiplegic patient of stroke origin were randomly allocated to control and experimental group. Experimental group received electrical stimulation apart from exercises given to both the groups for 2 weeks. Deltoid, infraspinatus and upper trapezius were stimulated, along with attempt to contract the muscles. Stroke Rehabilitation Assessment of Movement (STREAM upper components and manual muscle testing were used for evaluation of outcome. Wilcoxon sign rank test and chi-square tests were used for statistics. Results: Experimental group demonstrated greater recovery compared to control group. In both groups trapezius muscle work showed improvement in large number of patients followed by deltoid. STREAM score changes were seen a more number of patients in experimental group than control group. Conclusion: Electrical stimulation can be considered as an adjunct to exercises around shoulder in early stroke rehabilitation

  2. Control of standing balance at leaning postures with functional neuromuscular stimulation following spinal cord injury.

    Science.gov (United States)

    Audu, Musa L; Odle, Brooke M; Triolo, Ronald J

    2017-07-24

    This study systematically explored the potential of applying feedback control of functional neuromuscular stimulation (FNS) for stabilizing various erect and leaning standing postures after spinal cord injury (SCI). Perturbations ranging from 2 to 6% body weight were applied to two subjects with motor complete thoracic level SCI who were proficient at standing with implanted multichannel neural stimulators to activate the ankle, knee, hip and trunk muscles. The subjects stood with four different postures: erect, forward, forward-right and forward-left. Repeatable and controlled perturbations were applied in the forward, backward, rightward and leftward directions by linear actuators pulling on ropes attached to the subjects via a belt worn just above the waist. Upper extremity (UE) forces exerted on a stationary walker were measured with load cells attached to the handles. A feedback controller based on center of pressure (CoP) varied the stimulation levels to the otherwise paralyzed muscles so as to resist the effects of the perturbations. The effect of the feedback controller was compared to the case where only open-loop baseline stimulation was applied. This was done in terms of: (a) maximum resultant UE force exerted by the subjects on the walker, (b) maximum resultant CoP overshoot and (c) CoP root-mean-square deviation (RMSD). Feedback control resulted in significant reductions in the mean values of the majority of outcome values compared to baseline open-loop stimulation. Maximum resultant UE force was reduced by as much as 50% in one of the postures for one of the subjects. RMSD and maximum CoPs were reduced by as much as 75 and 70%, respectively, with feedback control. These results indicate that feedback control can be used to reject destabilizing disturbances in individuals with SCI using FNS not only for erect postures but also for leaning postures typically adopted during reaching while attempting various activities of daily living.

  3. The effects of vestibular stimulation and fatigue on postural control in classical ballet dancers.

    Science.gov (United States)

    Hopper, Diana M; Grisbrook, Tiffany L; Newnham, Prudence J; Edwards, Dylan J

    2014-01-01

    This study aimed to investigate the effects of ballet-specific vestibular stimulation and fatigue on static postural control in ballet dancers and to establish whether these effects differ across varying levels of ballet training. Dancers were divided into three groups: professional, pre-professional, and recreational. Static postural control of 23 dancers was measured on a force platform at baseline and then immediately, 30 seconds, and 60 seconds after vestibular stimulation (pirouettes) and induction of fatigue (repetitive jumps). The professional dancers' balance was unaffected by both the vestibular stimulation and the fatigue task. The pre-professional and recreational dancers' static sway increased following both perturbations. It is concluded that professional dancers are able to compensate for vestibular and fatiguing perturbations due to a higher level of skill-specific motor training.

  4. Pattern manipulation via on-chip phase modulation between orbital angular momentum beams

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huanlu [Department of Electrical and Electronic Engineering, University of Bristol, University Walk, Bristol BS8 1TR (United Kingdom); School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LP (United Kingdom); Strain, Michael J. [School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LP (United Kingdom); Wolfson Centre, Institute of Photonics, University of Strathclyde, 106 Rottenrow East, Glasgow G4 0NW (United Kingdom); Meriggi, Laura; Sorel, Marc [School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LP (United Kingdom); Chen, Lifeng; Zhu, Jiangbo; Cicek, Kenan [Department of Electrical and Electronic Engineering, University of Bristol, University Walk, Bristol BS8 1TR (United Kingdom); Wang, Jianwei; Thompson, Mark G. [Centre for Quantum Photonics, H. H. Wills Physics Laboratory and Department of Electrical and Electronic Engineering, University of Bristol, Bristol BS8 1UB (United Kingdom); Cai, Xinlun, E-mail: caixlun5@mail.sysu.edu.cn [Centre for Quantum Photonics, H. H. Wills Physics Laboratory and Department of Electrical and Electronic Engineering, University of Bristol, Bristol BS8 1UB (United Kingdom); State Key Laboratory of Optoelectronic Materials and Technologies and School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Yu, Siyuan, E-mail: s.yu@bristol.ac.uk [Department of Electrical and Electronic Engineering, University of Bristol, University Walk, Bristol BS8 1TR (United Kingdom); State Key Laboratory of Optoelectronic Materials and Technologies and School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2015-08-03

    An integrated approach to thermal modulation of relative phase between two optical vortices with opposite chirality has been demonstrated on a silicon-on-insulator substrate. The device consists of a silicon-integrated optical vortex emitter and a phase controlled 3 dB coupler. The relative phase between two optical vortices can be actively modulated on chip by applying a voltage on the integrated heater. The phase shift is shown to be linearly proportional to applied electrical power, and the rotation angle of the interference pattern is observed to be inversely proportional to topological charge. This scheme can be used in lab-on-chip, communications and sensing applications. It can be intentionally implemented with other modulation elements to achieve more complicated applications.

  5. Controlling the oscillation phase through precisely timed closed-loop optogenetic stimulation: a computational study

    Science.gov (United States)

    Witt, Annette; Palmigiano, Agostina; Neef, Andreas; El Hady, Ahmed; Wolf, Fred; Battaglia, Demian

    2013-01-01

    Dynamic oscillatory coherence is believed to play a central role in flexible communication between brain circuits. To test this communication-through-coherence hypothesis, experimental protocols that allow a reliable control of phase-relations between neuronal populations are needed. In this modeling study, we explore the potential of closed-loop optogenetic stimulation for the control of functional interactions mediated by oscillatory coherence. The theory of non-linear oscillators predicts that the efficacy of local stimulation will depend not only on the stimulation intensity but also on its timing relative to the ongoing oscillation in the target area. Induced phase-shifts are expected to be stronger when the stimulation is applied within specific narrow phase intervals. Conversely, stimulations with the same or even stronger intensity are less effective when timed randomly. Stimulation should thus be properly phased with respect to ongoing oscillations (in order to optimally perturb them) and the timing of the stimulation onset must be determined by a real-time phase analysis of simultaneously recorded local field potentials (LFPs). Here, we introduce an electrophysiologically calibrated model of Channelrhodopsin 2 (ChR2)-induced photocurrents, based on fits holding over two decades of light intensity. Through simulations of a neural population which undergoes coherent gamma oscillations—either spontaneously or as an effect of continuous optogenetic driving—we show that precisely-timed photostimulation pulses can be used to shift the phase of oscillation, even at transduction rates smaller than 25%. We consider then a canonic circuit with two inter-connected neural populations oscillating with gamma frequency in a phase-locked manner. We demonstrate that photostimulation pulses applied locally to a single population can induce, if precisely phased, a lasting reorganization of the phase-locking pattern and hence modify functional interactions between the

  6. Controlling the oscillation phase through precisely timed closed-loop optogenetic stimulation: a computational study

    Directory of Open Access Journals (Sweden)

    Annette eWitt

    2013-04-01

    Full Text Available Dynamic oscillatory coherence is believed to play a central role in flexible communication between brain circuits. To test this communication-through-coherence hypothesis, experimental protocols that allow a reliable control of phase-relations between neuronal populations are needed. In this modeling study, we explore the potential of closed-loop optogenetic stimulation for the control of functional interactions mediated by oscillatory coherence. The theory of nonlinear oscillators predicts that the efficacy of local stimulation will depend not only on the stimulation intensity but also on its timing relative to the ongoing oscillation in the target area. Induced phase-shifts are expected to be stronger when the stimulation is applied within specific narrow phase intervals. Conversely, stimulations with the same or even stronger intensity are less effective when timed randomly. Stimulation should thus be properly phased with respect to ongoing oscillations (in order to optimally perturb them and the timing of the stimulation onset must be determined by a real-time phase analysis of simultaneously recorded local field potentials (LFPs.Here, we introduce an electrophysiologically calibrated model of Channelrhodopsin 2 (ChR2-induced photocurrents, based on fits holding over two decades of light intensity. Through simulations of a neural population which undergoes coherent gamma oscillations —either spontaneously or as an effect of continuous optogenetic driving—, we show that precisely-timed photostimulation pulses can be used to shift phase, even at transduction rates smaller than 25%. We consider then a canonic circuit with two inter-connected neural populations oscillating with gamma frequency in a phase-locked manner. We demonstrate that photostimulation pulses applied locally to a single population can induce, if precisely phased, a lasting reorganization of the phase-locking pattern and hence modify functional interactions between the two

  7. Manually operatable on-chip bistable pneumatic microstructures for microfluidic manipulations.

    Science.gov (United States)

    Chen, Arnold; Pan, Tingrui

    2014-09-07

    Bistable microvalves are of particular interest because of their distinct nature of requiring energy consumption only during the transition between the open and closed states. This characteristic can be highly advantageous in reducing the number of external inputs and the complexity of control circuitries since microfluidic devices as contemporary lab-on-a-chip platforms are transferring from research settings to low-resource environments with high integrability and a small form factor. In this paper, we first present manually operatable, on-chip bistable pneumatic microstructures (BPMs) for microfluidic manipulation. The structural design and operation of the BPM devices can be readily integrated into any pneumatically powered microfluidic network consisting of pneumatic and fluidic channels. It is mainly composed of a vacuum activation chamber (VAC) and a pressure release chamber (PRC), of which users have direct control through finger pressing to switch either to the bistable vacuum state (VS) or the atmospheric state (AS). We have integrated multiple BPM devices into a 4-to-1 microfluidic multiplexor to demonstrate on-chip digital flow switching from different sources. Furthermore, we have shown its clinical relevance in a point-of-care diagnostic chip that processes blood samples to identify the distinct blood types (A/B/O) on-chip.

  8. Dynamic control of modeled tonic-clonic seizure states with closed-loop stimulation

    Directory of Open Access Journals (Sweden)

    Bryce eBeverlin II

    2013-02-01

    Full Text Available Seizure control using deep brain stimulation (DBS provides an alternative therapy to patients with intractable and drug resistant epilepsy. This paper presents novel DBS stimulus protocols to disrupt seizures. Two protocols are presented: open-loop stimulation and a closed-loop feedback system utilizing measured firing rates to adjust stimulus frequency. Stimulation suppression is demonstrated in a computational model using 3000 excitatory Morris-Lecar model neurons connected with depressing synapses. Cells are connected using second order network topology to simulate network topologies measured in cortical networks. The network spontaneously switches from tonic to clonic as synaptic strengths and tonic input to the neurons decreases. To this model we add periodic stimulation pulses to simulate DBS. Periodic forcing can synchronize or desynchronize an oscillating population of neurons, depending on the stimulus frequency and amplitude. Therefore, it is possible to either extend or truncate the tonic or clonic phases of the seizure. Stimuli applied at the firing rate of the neuron generally synchronize the population while stimuli slightly slower than the firing rate prevent synchronization. We present an adaptive stimulation algorithm that measures the firing rate of a neuron and adjusts the stimulus to maintain a relative stimulus frequency to firing frequency and demonstrate it in a computational model of a tonic-clonic seizure. This adaptive algorithm can affect the duration of the tonic phase using much smaller stimulus amplitudes than the open-loop control.

  9. Randomized controlled trial of surface peroneal nerve stimulation for motor relearning in lower limb hemiparesis

    NARCIS (Netherlands)

    Sheffler, L.R.; Taylor, P.N.; Gunzler, D.D.; Buurke, Jaap; IJzerman, Maarten Joost; Chae, J.

    2013-01-01

    Objective: To compare the motor relearning effect of a surface peroneal nerve stimulator (PNS) versus usual care on lower limb motor impairment, activity limitation, and quality of life among chronic stroke survivors. Design: Single-blinded randomized controlled trial. Setting: Teaching hospital of

  10. Randomized controlled trial of surface peroneal nerve stimulation for motor relearning in lower limb hemiparesis

    NARCIS (Netherlands)

    Sheffler, L.R.; Taylor, P.N.; Gunzler, D.D.; Buurke, J.H.; IJzerman, M.J.; Chae, J.

    2013-01-01

    Objective: To compare the motor relearning effect of a surface peroneal nerve stimulator (PNS) versus usual care on lower limb motor impairment, activity limitation, and quality of life among chronic stroke survivors. Design: Single-blinded randomized controlled trial. Setting: Teaching hospital of

  11. Neuropsychological effects of bilateral STN stimulation in Parkinson disease - A controlled study

    NARCIS (Netherlands)

    Smeding, HMM; Koning-Haanstra, M; Schuurman, PR; Nijssen, P; van Laar, T; Schmand, B; Speelman, J.D.

    2006-01-01

    Objective: To evaluate the cognitive and behavioral effects of bilateral subthalamic nucleus (STN) stimulation in patients with Parkinson disease (PD). Methods: The authors included 103 patients; 99 patients were evaluated 6 months after surgery. A control group of 39 patients with PD was formed and

  12. Workshop meeting report Organs-on-Chips: human disease models.

    Science.gov (United States)

    van de Stolpe, Anja; den Toonder, Jaap

    2013-09-21

    The concept of "Organs-on-Chips" has recently evolved and has been described as 3D (mini-) organs or tissues consisting of multiple and different cell types interacting with each other under closely controlled conditions, grown in a microfluidic chip, and mimicking the complex structures and cellular interactions in and between different cell types and organs in vivo, enabling the real time monitoring of cellular processes. In combination with the emerging iPSC (induced pluripotent stem cell) field this development offers unprecedented opportunities to develop human in vitro models for healthy and diseased organ tissues, enabling the investigation of fundamental mechanisms in disease development, drug toxicity screening, drug target discovery and drug development, and the replacement of animal testing. Capturing the genetic background of the iPSC donor in the organ or disease model carries the promise to move towards "in vitro clinical trials", reducing costs for drug development and furthering the concept of personalized medicine and companion diagnostics. During the Lorentz workshop (Leiden, September 2012) an international multidisciplinary group of experts discussed the current state of the art, available and emerging technologies, applications and how to proceed in the field. Organ-on-a-chip platform technologies are expected to revolutionize cell biology in general and drug development in particular.

  13. Automatic control of a drop-foot stimulator based on angle measurement using bioimpedance.

    Science.gov (United States)

    Nahrstaedt, Holger; Schauer, Thomas; Shalaby, Raafat; Hesse, Stefan; Raisch, Jörg

    2008-08-01

    The topic of this contribution is iterative learning control of a drop-foot stimulator in which a predefined angle profile during the swing phase is realized. Ineffective dorsiflexion is compensated by feedback-controlled stimulation of the muscle tibialis anterior. The ankle joint measurement is based on changes in the bioimpedance (BI) caused by leg movements. A customized four-channel BI measurement system was developed. The suggested control approach and the new measurement method for the joint angle were successfully tested in preliminary experiments with a neurologically intact subject. Reference angle measurements were taken with a marker-based optical system. An almost linear relation between joint angle and BI was found for the angle range applicable during gait. The desired angle trajectory was closely tracked by the iterative learning controller after three gait cycles. The final root mean square tracking error was below 5 degrees.

  14. Focal electrical stimulation as an effective sham control for active rTMS and biofeedback treatments

    Science.gov (United States)

    Sheffer, Christine E; Mennemeier, Mark; Landes, Reid D; Dornhoffer, John; Kimbrell, Timothy; Bickel, Warren; Brackman, Sharon; Chelette, Kenneth C; Brown, Ginger; Vuong, Mai

    2013-01-01

    A valid sham control is important for determining the efficacy and effectiveness of repetitive transcranial magnetic stimulation (rTMS) as an experimental and clinical tool. Given the manner in which rTMS is applied, separately or in combination with self-regulatory approaches, and its intended impact on brain states, a valid sham control of this type may well serve as a meaningful control for biofeedback studies, where efforts to develop a credible control have often been less than ideal. This study examined the effectiveness of focal electrical stimulation of the frontalis muscle as a sham technique for blinding participants to high-frequency rTMS over the dorso-lateral prefrontal cortex (DLPFC) at durations, intensities, and schedules of stimulation similar to many clinical applications. In this within-subjects single blind design, 19 participants made guesses immediately after receiving 54 counterbalanced rTMS sessions (sham, 10Hz, 20Hz); 7 (13%) of the guesses were made for sham, 31 (57%) were made for 10Hz, and 16 (30%) were made for 20Hz. Participants correctly guessed the sham condition 6% (CI: 1%, 32%) of the time, which is less than the odds of chance (i.e., of guessing at random, 33%); correctly guessed the 10Hz condition 66% (CI: 43%, 84%) of the time, which was greater than chance; and correctly guessed the 20Hz condition 41% (CI: 21%, 65%) of the time, which was no different than chance. Focal electrical stimulation therefore can be an effective sham control for high-frequency rTMS of the DLPFC, as well as for active biofeedback interventions. Participants were unaware that electrical stimulation was, in fact, sham rTMS. PMID:23702828

  15. PERFORMANCE ENHANCED ROUTER DESIGN FOR NETWORK ON CHIP

    Directory of Open Access Journals (Sweden)

    Anbu chozhan.P

    2013-04-01

    Full Text Available Network on chip is a new paradigm for on chip design that is able to sustain the communication provisions for the SoC with the desired performance. NOC applies networking methodology concepts to system on chip data transfer and it gives noticeable elevation over conventionalbus based communication. NOC router is the backbone of on chip communication which directs the flow of data. In NOC router the arbiter is used during number of inputs request for the similar out port. Arbiter generates the grant based on the priority and previous granted input. For NOC router we have design the efficient round robin arbiter and analyse the power and area. In this paper on chip router is designed with a buffering technique of FWFT based asynchronous FIFO which improves timing and reduce power consumption. The proposed design of router is simulated and synthesized in Xilinx ISE 13.2 and the source code is written in Verilog. Cadence soc encounter of technology ami035 is used to generate layout of router and RTL compiler is used to compute area, power and timing.

  16. A modular, computer-controlled system for olfactory stimulation in the MRI environment.

    Science.gov (United States)

    Andrieu, Patrice; Bonnans, Vincent; Meneses, Jaime; Millot, Jean-Louis; Moulin, Thierry; Gharbi, Tijani

    2014-03-01

    Although the cerebral networks involved in sensory perception are of general interest in neuroscience, registration of the effects of olfactory stimulation, especially in a magnetic resonance imaging (MRI) environment, presents particular problems and constraints. This article presents details of a reliable and portable system for olfactory stimulation that is modular in design and based on microcontroller technology. It has the following characteristics: (1) It is under software control; (2) the presentation of olfactory stimulation can be synchronized with respiration; (3) it can be manually controlled; and (4) it is fully compatible with an MRI environment. The principle underlying this system is to direct an odor to the subject's nostrils by switching airflow to different odor diffusers. The characteristics of this system were established using (1) ultraviolet (UV) spectroscopy, to measure its response time, and (2) gas chromatography, to measure the repeatability of odor presentation in terms of gas concentration. A response time of 200 ± 25 ms was obtained for the system, and the standard deviations of the gas concentration delivered during stimulation ranged from 1.5% to 22%, depending on the odor, the airflow, and the dilution of the odor used. Since it is portable, controlled by software, and reliable, on the basis of the results we obtained, this system will lend itself to a wide range of applications in olfactory neuroscience.

  17. Optimal control of directional deep brain stimulation in the parkinsonian neuronal network

    Science.gov (United States)

    Fan, Denggui; Wang, Zhihui; Wang, Qingyun

    2016-07-01

    The effect of conventional deep brain stimulation (DBS) on debilitating symptoms of Parkinson's disease can be limited because it can only yield the spherical field. And, some side effects are clearly induced with influencing their adjacent ganglia. Recent experimental evidence for patients with Parkinson's disease has shown that a novel DBS electrode with 32 independent stimulation source contacts can effectively optimize the clinical therapy by enlarging the therapeutic windows, when it is applied on the subthalamic nucleus (STN). This is due to the selective activation in clusters of various stimulation contacts which can be steered directionally and accurately on the targeted regions of interest. In addition, because of the serious damage to the neural tissues, the charge-unbalanced stimulation is not typically indicated and the real DBS utilizes charge-balanced bi-phasic (CBBP) pulses. Inspired by this, we computationally investigate the optimal control of directional CBBP-DBS from the proposed parkinsonian neuronal network of basal ganglia-thalamocortical circuit. By appropriately tuning stimulation for different neuronal populations, it can be found that directional steering CBBP-DBS paradigms are superior to the spherical case in improving parkinsonian dynamical properties including the synchronization of neuronal populations and the reliability of thalamus relaying the information from cortex, which is in a good agreement with the physiological experiments. Furthermore, it can be found that directional steering stimulations can increase the optimal stimulation intensity of desynchronization by more than 1 mA compared to the spherical case. This is consistent with the experimental result with showing that there exists at least one steering direction that can allow increasing the threshold of side effects by 1 mA. In addition, we also simulate the local field potential (LFP) and dominant frequency (DF) of the STN neuronal population induced by the activation

  18. Influence of Transcranial Direct Current Stimulation to the Cerebellum on Standing Posture Control

    Directory of Open Access Journals (Sweden)

    Yasuto Inukai

    2016-07-01

    Full Text Available Damage to the vestibular cerebellum results in dysfunctional standing posture control. Patients with cerebellum dysfunction have a larger sway in the center of gravity while standing compared with healthy subjects. Transcranial direct current stimulation (tDCS is a noninvasive technique for selectively exciting or inhibiting specific neural structures with potential applications in functional assessment and treatment of neural disorders. However, the specific stimulation parameters for influencing postural control have not been assessed. In this study, we investigated the influence of tDCS when applied over the cerebellum on standing posture control. Sixteen healthy subjects received tDCS (20 min, 2 mA over the scalp 2 cm below the inion. In experiment 1, all 16 subjects received tDCS under three stimulus conditions, Sham, Cathodal, and Anodal, in a random order with the second electrode placed on the forehead. In experiment 2, five subjects received cathodal stimulation only with the second electrode placed over the right buccinator muscle. Center of gravity sway was measured twice for 60 s before and after tDCS in a standing posture with eyes open and legs closed, and average total locus length, locus length per second, rectangular area, and enveloped area were calculated. In experiment 1, total locus length and locus length per second decreased significantly after cathodal stimulation but not after anodal or sham stimulation, while no tDCS condition influenced rectangular or enveloped areas. In experiment 2, cathodal tDCS again significantly reduced total locus length and locus length per second but not rectangular and enveloped areas. The effects of tDCS on postural control are polarity-dependent, likely reflecting the selective excitation or inhibition of cerebellar Purkinje cells. Cathodal tDCS to the cerebellum of healthy subjects can alter body sway (velocity.

  19. Multifunctional System-on-Glass for Lab-on-Chip applications.

    Science.gov (United States)

    Petrucci, G; Caputo, D; Lovecchio, N; Costantini, F; Legnini, I; Bozzoni, I; Nascetti, A; de Cesare, G

    2017-07-15

    Lab-on-Chip are miniaturized systems able to perform biomolecular analysis in shorter time and with lower reagent consumption than a standard laboratory. Their miniaturization interferes with the multiple functions that the biochemical procedures require. In order to address this issue, our paper presents, for the first time, the integration on a single glass substrate of different thin film technologies in order to develop a multifunctional platform suitable for on-chip thermal treatments and on-chip detection of biomolecules. The proposed System on-Glass hosts thin metal films acting as heating sources; hydrogenated amorphous silicon diodes acting both as temperature sensors to monitor the temperature distribution and photosensors for the on-chip detection and a ground plane ensuring that the heater operation does not affect the photodiode currents. The sequence of the technological steps, the deposition temperatures of the thin films and the parameters of the photolithographic processes have been optimized in order to overcome all the issues of the technological integration. The device has been designed, fabricated and tested for the implementation of DNA amplification through the Polymerase Chain Reaction (PCR) with thermal cycling among three different temperatures on a single site. The glass has been connected to an electronic system that drives the heaters and controls the temperature and light sensors. It has been optically and thermally coupled with another glass hosting a microfluidic network made in polydimethylsiloxane that includes thermally actuated microvalves and a PCR process chamber. The successful DNA amplification has been verified off-chip by using a standard fluorometer.

  20. An integrated lab-on-chip for rapid identification and simultaneous differentiation of tropical pathogens.

    Directory of Open Access Journals (Sweden)

    Jeslin J L Tan

    Full Text Available Tropical pathogens often cause febrile illnesses in humans and are responsible for considerable morbidity and mortality. The similarities in clinical symptoms provoked by these pathogens make diagnosis difficult. Thus, early, rapid and accurate diagnosis will be crucial in patient management and in the control of these diseases. In this study, a microfluidic lab-on-chip integrating multiplex molecular amplification and DNA microarray hybridization was developed for simultaneous detection and species differentiation of 26 globally important tropical pathogens. The analytical performance of the lab-on-chip for each pathogen ranged from 102 to 103 DNA or RNA copies. Assay performance was further verified with human whole blood spiked with Plasmodium falciparum and Chikungunya virus that yielded a range of detection from 200 to 4×105 parasites, and from 250 to 4×107 PFU respectively. This lab-on-chip was subsequently assessed and evaluated using 170 retrospective patient specimens in Singapore and Thailand. The lab-on-chip had a detection sensitivity of 83.1% and a specificity of 100% for P. falciparum; a sensitivity of 91.3% and a specificity of 99.3% for P. vivax; a positive 90.0% agreement and a specificity of 100% for Chikungunya virus; and a positive 85.0% agreement and a specificity of 100% for Dengue virus serotype 3 with reference methods conducted on the samples. Results suggested the practicality of an amplification microarray-based approach in a field setting for high-throughput detection and identification of tropical pathogens.

  1. An Integrated Lab-on-Chip for Rapid Identification and Simultaneous Differentiation of Tropical Pathogens

    Science.gov (United States)

    Sato, Mitsuharu; Watthanaworawit, Wanitda; Ling, Clare L.; Mauduit, Marjorie; Malleret, Benoît; Grüner, Anne-Charlotte; Tan, Rosemary; Nosten, François H.; Snounou, Georges; Rénia, Laurent; Ng, Lisa F. P.

    2014-01-01

    Tropical pathogens often cause febrile illnesses in humans and are responsible for considerable morbidity and mortality. The similarities in clinical symptoms provoked by these pathogens make diagnosis difficult. Thus, early, rapid and accurate diagnosis will be crucial in patient management and in the control of these diseases. In this study, a microfluidic lab-on-chip integrating multiplex molecular amplification and DNA microarray hybridization was developed for simultaneous detection and species differentiation of 26 globally important tropical pathogens. The analytical performance of the lab-on-chip for each pathogen ranged from 102 to 103 DNA or RNA copies. Assay performance was further verified with human whole blood spiked with Plasmodium falciparum and Chikungunya virus that yielded a range of detection from 200 to 4×105 parasites, and from 250 to 4×107 PFU respectively. This lab-on-chip was subsequently assessed and evaluated using 170 retrospective patient specimens in Singapore and Thailand. The lab-on-chip had a detection sensitivity of 83.1% and a specificity of 100% for P. falciparum; a sensitivity of 91.3% and a specificity of 99.3% for P. vivax; a positive 90.0% agreement and a specificity of 100% for Chikungunya virus; and a positive 85.0% agreement and a specificity of 100% for Dengue virus serotype 3 with reference methods conducted on the samples. Results suggested the practicality of an amplification microarray-based approach in a field setting for high-throughput detection and identification of tropical pathogens. PMID:25078474

  2. Novel microfluidic platform for automated lab-on-chip testing of hypercoagulability panel.

    Science.gov (United States)

    Emani, Sirisha; Sista, Ramakrishna; Loyola, Hugo; Trenor, Cameron C; Pamula, Vamsee K; Emani, Sitaram M

    2012-12-01

    Current methods for hypercoagulability panel testing require large blood volumes and long turn-around testing times. A novel microfluidic platform has been designed to perform automated multiplexed hypercoagulability panel testing at near patient, utilizing only a single droplet of blood sample. We test the hypothesis that this novel platform could be utilized to perform specific multiplexed ELISA-based hypercoagulability panel testing for antithrombin III, protein C, protein S and factor VIII antigens, as well as anticardiolipin/human anti-β2-glycoprotein-1 IgG antibodies--on blood samples. Sandwich ELISA was modified by utilizing magnetic beads coated with specific antibodies as the solid phase using fluorescence readout. Percentage recovery was calculated using four-parameter logistic curves. On-chip ELISA with single factors was compared with multiplex factor ELISA for known concentrations of sample. Blood samples were analyzed on-chip and compared with traditional bench-top assays. Time for multiplexed performance of hypercoagulability panel ELISA on-chip with controls is 72 min. Recovery rates (range 80-120%) for known concentrations of specific factors was not significantly different when assays were performed using a single factor vs. multiplex factor analysis. Assay results were not significantly different between individual assays performed either on bench-top or on-chip with patient blood and/or plasma. Utilizing a novel digital microfluidic platform, we demonstrate the feasibility of automated hypercoagulability panel testing on small volume of plasma and whole blood patient samples with high fidelity. Further investigation is required to test the application of this novel technology at point-of-care clinical settings.

  3. On-chip sample preparation for complete blood count from raw blood.

    Science.gov (United States)

    Nguyen, John; Wei, Yuan; Zheng, Yi; Wang, Chen; Sun, Yu

    2015-03-21

    This paper describes a monolithic microfluidic device capable of on-chip sample preparation for both RBC and WBC measurements from whole blood. For the first time, on-chip sample processing (e.g. dilution, lysis, and filtration) and downstream single cell measurement were fully integrated to enable sample preparation and single cell analysis from whole blood on a single device. The device consists of two parallel sub-systems that perform sample processing and electrical measurements for measuring RBC and WBC parameters. The system provides a modular environment capable of handling solutions of various viscosities by adjusting the length of channels and precisely controlling mixing ratios, and features a new 'offset' filter configuration for increased duration of device operation. RBC concentration, mean corpuscular volume (MCV), cell distribution width, WBC concentration and differential are determined by electrical impedance measurement. Experimental characterization of over 100,000 cells from 10 patient blood samples validated the system's capability for performing on-chip raw blood processing and measurement.

  4. Technologies for autonomous integrated lab-on-chip systems for space missions

    Science.gov (United States)

    Nascetti, A.; Caputo, D.; Scipinotti, R.; de Cesare, G.

    2016-11-01

    Lab-on-chip devices are ideal candidates for use in space missions where experiment automation, system compactness, limited weight and low sample and reagent consumption are required. Currently, however, most microfluidic systems require external desktop instrumentation to operate and interrogate the chip, thus strongly limiting their use as stand-alone systems. In order to overcome the above-mentioned limitations our research group is currently working on the design and fabrication of "true" lab-on-chip systems that integrate in a single device all the analytical steps from the sample preparation to the detection without the need for bulky external components such as pumps, syringes, radiation sources or optical detection systems. Three critical points can be identified to achieve 'true' lab-on-chip devices: sample handling, analytical detection and signal transduction. For each critical point, feasible solutions are presented and evaluated. Proposed microfluidic actuation and control is based on electrowetting on dielectrics, autonomous capillary networks and active valves. Analytical detection based on highly specific chemiluminescent reactions is used to avoid external radiation sources. Finally, the integration on the same chip of thin film sensors based on hydrogenated amorphous silicon is discussed showing practical results achieved in different sensing tasks.

  5. Integrated lab-on-chip biosensing systems based on magnetic particle actuation--a comprehensive review.

    Science.gov (United States)

    van Reenen, Alexander; de Jong, Arthur M; den Toonder, Jaap M J; Prins, Menno W J

    2014-06-21

    The demand for easy to use and cost effective medical technologies inspires scientists to develop innovative lab-on-chip technologies for point-of-care in vitro diagnostic testing. To fulfill medical needs, the tests should be rapid, sensitive, quantitative, and miniaturizable, and need to integrate all steps from sample-in to result-out. Here, we review the use of magnetic particles actuated by magnetic fields to perform the different process steps that are required for integrated lab-on-chip diagnostic assays. We discuss the use of magnetic particles to mix fluids, to capture specific analytes, to concentrate analytes, to transfer analytes from one solution to another, to label analytes, to perform stringency and washing steps, and to probe biophysical properties of the analytes, distinguishing methodologies with fluid flow and without fluid flow (stationary microfluidics). Our review focuses on efforts to combine and integrate different magnetically actuated assay steps, with the vision that it will become possible in the future to realize integrated lab-on-chip biosensing assays in which all assay process steps are controlled and optimized by magnetic forces.

  6. Blood cleaner on-chip design for artificial human kidney manipulation

    Directory of Open Access Journals (Sweden)

    Suwanpayak N

    2011-05-01

    Full Text Available N Suwanpayak1, MA Jalil2, MS Aziz3, FD Ismail3, J Ali3, PP Yupapin11Nanoscale Science and Engineering Research Alliance (N'SERA, Advanced Research Center for Photonics, Faculty of Science, King Mongkut's Institute of Technology, Ladkrabang, Bangkok, Thailand; 2Ibnu Sina Institute of Fundamental Science Studies (IIS, 3Institute of Advanced Photonics Science, Nanotechnology Research Alliance, Universiti Teknologi Malaysia, Johor Bahru, MalaysiaAbstract: A novel design of a blood cleaner on-chip using an optical waveguide known as a PANDA ring resonator is proposed. By controlling some suitable parameters, the optical vortices (gradient optical fields/wells can be generated and used to form the trapping tools in the same way as optical tweezers. In operation, the trapping force is formed by the combination between the gradient field and scattering photons by using the intense optical vortices generated within the PANDA ring resonator. This can be used for blood waste trapping and moves dynamically within the blood cleaner on-chip system (artificial kidney, and is performed within the wavelength routers. Finally, the blood quality test is exploited by the external probe before sending to the destination. The advantage of the proposed kidney on-chip system is that the unwanted substances can be trapped and filtered from the artificial kidney, which can be available for blood cleaning applications.Keywords: optical trapping, blood dialysis, blood cleaner, human kidney manipulation

  7. On-chip passive three-port circuit of all-optical ordered-route transmission

    Science.gov (United States)

    Liu, Li; Dong, Jianji; Gao, Dingshan; Zheng, Aoling; Zhang, Xinliang

    2015-05-01

    On-chip photonic circuits of different specific functions are highly desirable and becoming significant demands in all-optical communication network. Especially, the function to control the transmission directions of the optical signals in integrated circuits is a fundamental research. Previous schemes, such as on-chip optical circulators, are mostly realized by Faraday effect which suffers from material incompatibilities between semiconductors and magneto-optical materials. Achieving highly functional circuits in which light circulates in a particular direction with satisfied performances are still difficult in pure silicon photonics platform. Here, we propose and experimentally demonstrate a three-port passive device supporting optical ordered-route transmission based on silicon thermo-optic effect for the first time. By injecting strong power from only one port, the light could transmit through the three ports in a strict order (1→2, 2→3, 3→1) while be blocked in the opposite order (1→3, 3→2, 2→1). The blocking extinction ratios and operation bandwidths have been investigated in this paper. Moreover, with compact size, economic fabrication process and great extensibility, this proposed photonic integrated circuit is competitive to be applied in on-chip all-optical information processing systems, such as path priority selector.

  8. Radial Basis Function Neural Network-based PID model for functional electrical stimulation system control.

    Science.gov (United States)

    Cheng, Longlong; Zhang, Guangju; Wan, Baikun; Hao, Linlin; Qi, Hongzhi; Ming, Dong

    2009-01-01

    Functional electrical stimulation (FES) has been widely used in the area of neural engineering. It utilizes electrical current to activate nerves innervating extremities affected by paralysis. An effective combination of a traditional PID controller and a neural network, being capable of nonlinear expression and adaptive learning property, supply a more reliable approach to construct FES controller that help the paraplegia complete the action they want. A FES system tuned by Radial Basis Function (RBF) Neural Network-based Proportional-Integral-Derivative (PID) model was designed to control the knee joint according to the desired trajectory through stimulation of lower limbs muscles in this paper. Experiment result shows that the FES system with RBF Neural Network-based PID model get a better performance when tracking the preset trajectory of knee angle comparing with the system adjusted by Ziegler- Nichols tuning PID model.

  9. Tremor suppression using functional electrical stimulation: a comparison between digital and analog controllers.

    Science.gov (United States)

    Gillard, D M; Cameron, T; Prochazka, A; Gauthier, M J

    1999-09-01

    In this study, we compared digital and analog versions of a functional electrical stimulator designed to suppress tremor. The device was based on a closed-loop control system designed to attenuate movements in the tremor frequency range, without significantly affecting slower, voluntary movements. Testing of the digital filter was done on three patients with Parkinsonian tremor and the results compared to those of a functional electrical stimulation device based on an analog filter evaluated in a previous study. Additional testing of both the analog and digital filters was done on three subjects with no neurological impairment performing tremor-like movements and slow voluntary movements. We found that the digital controller provided a mean attenuation of 84%, compared to 65% for the analog controller.

  10. The Effects of Electrical Muscle Stimulation on Glucose Control in Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    A Ashraf

    2010-04-01

    Full Text Available Introduction & Objective: Diabetes, i.e. lack of proper control of blood sugar, may cause serious complications in patients. The objective of this study was to assess the influence of electrical muscle stimulation on glucose control in type 2 diabetes mellitus. Materials & Methods: This clinical-trial study was conducted in 2009, in Shiraz, Iran. Forty nine diabetes mellitus patients, Type 2, participated in this study. In 28 cases, dietary and exercise modifications were recommended and electrical muscle stimulation was carried out. For the other 21 cases, only dietary and exercise modifications were recommended. Laboratory tests, including fasting blood sugar (FBS and glucose tolerance test (GTT, was performed before the study and 6 weeks afterward. The results were analyzed by SPSS version 15.5 software and using t-test. Results: The mean of FBS in the case group before EMS was 156 mg/dl and 6 weeks later changed to 123 mg/dl (p < 0.05, while in the control group these indices were 158 mg/dl and 154 mg/dl respectively. The mean of GTT in patients before EMS was 193 mg/dl and 6 weeks later became 150 mg/dl (p < 0.05, whereas in the control group these figures were 204 mg/dl and 201 mg/dl respectively. Conclusion: The results of this study confirmed that the use of electrical muscle stimulation can be effective on glucose control in type 2 diabetes mellitus.

  11. Waveguide coupled resonance fluorescence from on-chip quantum emitter.

    Science.gov (United States)

    Makhonin, Maxim N; Dixon, James E; Coles, Rikki J; Royall, Ben; Luxmoore, Isaac J; Clarke, Edmund; Hugues, Maxime; Skolnick, Maurice S; Fox, A Mark

    2014-12-10

    Resonantly driven quantum emitters offer a very promising route to obtain highly coherent sources of single photons required for applications in quantum information processing (QIP). Realizing this for on-chip scalable devices would be important for scientific advances and practical applications in the field of integrated quantum optics. Here we report on-chip quantum dot (QD) resonance fluorescence (RF) efficiently coupled into a single-mode waveguide, a key component of a photonic integrated circuit, with a negligible resonant laser background and show that the QD coherence is enhanced by more than a factor of 4 compared to off-resonant excitation. Single-photon behavior is confirmed under resonant excitation, and fast fluctuating charge dynamics are revealed in autocorrelation g((2)) measurements. The potential for triggered operation is verified in pulsed RF. These results pave the way to a novel class of integrated quantum-optical devices for on-chip quantum information processing with embedded resonantly driven quantum emitters.

  12. Exploring Alternative Topologies for Network-on-Chip Architectures

    Directory of Open Access Journals (Sweden)

    Shafi Patel

    2011-01-01

    Full Text Available With increase in integration density and complexity of the system-on-Chip (SOC, the conventional interconnects are not suitable to fulfill the demands. The application of traditional network technologies in the form of Network-on-Chip is a potential solution. NoC design space has many variables. Selection of a better topology results in lesser complexities and better power-efficiency. In the proposed work, key research area in Network-on-chip design targeting communication infrastructure specially focusing on optimized topology design is worked upon. The simulation is modeled using a conventional network simulator tool packet tracer 5.3, in which by selecting proposed Topology 35.7 % reduction in traversing the longest path is observed.

  13. A neurochemical closed-loop controller for deep brain stimulation: toward individualized smart neuromodulation therapies.

    Directory of Open Access Journals (Sweden)

    Peter Jonas Grahn

    2014-06-01

    Full Text Available Current strategies for optimizing deep brain stimulation (DBS therapy involve multiple postoperative visits. During each visit, stimulation parameters are adjusted until desired therapeutic effects are achieved and adverse effects are minimized. However, the efficacy of these therapeutic parameters may decline with time due at least in part to disease progression, interactions between the host environment and the electrode, and lead migration. As such, development of closed-loop control systems that can respond to changing neurochemical environments, tailoring DBS therapy to individual patients, is paramount for improving the therapeutic efficacy of DBS.Evidence obtained using electrophysiology and imaging techniques in both animals and humans suggests that DBS works by modulating neural network activity. Recently, animal studies have shown that stimulation-evoked changes in neurotransmitter release that mirror normal physiology are associated with the therapeutic benefits of DBS. Therefore, to fully understand the neurophysiology of DBS and optimize its efficacy, it may be necessary to look beyond conventional electrophysiological analyses and characterize the neurochemical effects of therapeutic and non-therapeutic stimulation. By combining electrochemical monitoring and mathematical modeling techniques, we can potentially replace the trial-and-error process used in clinical programming with deterministic approaches that help attain optimal and stable neurochemical profiles. In this manuscript, we summarize the current understanding of electrophysiological and electrochemical processing for control of neuromodulation therapies. Additionally, we describe a proof-of-principle closed-loop controller that characterizes DBS-evoked dopamine changes to adjust stimulation parameters in a rodent model of DBS. The work described herein represents the initial steps toward achieving a smart neuroprosthetic system for treatment of neurologic and

  14. On-Chip Integration of Cell-Free Gene Expression

    Science.gov (United States)

    Buxboim, Amnon; Morpurgo, Margherita; Bar-Dagan, Maya; Frydman, Veronica; Zbaida, David; Bar-Ziv, Roy

    2006-03-01

    We present a synthetic approach for the study of gene networks in vitro which is complementary to traditional in vivo methodologies. We have developed a technology for submicron integration of functional genes and on-chip protein synthesis using a cell-free transcription/translation system. The interaction between genes is facilitated by diffusion of on-chip gene expression products from `source' genes towards `acceptor' genes. Our technology is simple and inexpensive and can serve as an improved platform for a wide variety of protein and DNA biochip applications.

  15. Entangled photons from on-chip slow light

    CERN Document Server

    Takesue, Hiroki; Kuramochi, Eiichi; Notomi, Masaya

    2014-01-01

    We report the first entanglement generation experiment using an on-chip slow light device. With highly efficient spontaneous four-wave mixing enhanced by the slow light effect in a coupled resonator optical waveguide based on a silicon photonic crystal, we generated 1.5-$\\mu$m-band high-dimensional time-bin entangled photon pairs. We undertook two-photon interference experiments and observed the coincidence fringes with visibilities $>74\\%$. The present result enables us to realize an on-chip entanglement source with a very small footprint, which is an essential function for quantum information processing based on integrated quantum photonics.

  16. Ultrasound assisted particle and cell manipulation on-chip.

    Science.gov (United States)

    Mulvana, Helen; Cochran, Sandy; Hill, Martyn

    2013-11-01

    Ultrasonic fields are able to exert forces on cells and other micron-scale particles, including microbubbles. The technology is compatible with existing lab-on-chip techniques and is complementary to many alternative manipulation approaches due to its ability to handle many cells simultaneously over extended length scales. This paper provides an overview of the physical principles underlying ultrasonic manipulation, discusses the biological effects relevant to its use with cells, and describes emerging applications that are of interest in the field of drug development and delivery on-chip. © 2013.

  17. Designing network on-chip architectures in the nanoscale era

    CERN Document Server

    Flich, Jose

    2010-01-01

    Going beyond isolated research ideas and design experiences, Designing Network On-Chip Architectures in the Nanoscale Era covers the foundations and design methods of network on-chip (NoC) technology. The contributors draw on their own lessons learned to provide strong practical guidance on various design issues.Exploring the design process of the network, the first part of the book focuses on basic aspects of switch architecture and design, topology selection, and routing implementation. In the second part, contributors discuss their experiences in the industry, offering a roadmap to recent p

  18. On-chip photonic tweezers for photonics, microfluidics, and biology

    Science.gov (United States)

    Pin, Christophe; Renaut, Claude; Tardif, Manon; Jager, Jean-Baptiste; Delamadeleine, Eric; Picard, Emmanuel; Peyrade, David; Hadji, Emmanuel; de Fornel, Frédérique; Cluzel, Benoît

    2017-04-01

    Near-field optical forces arise from evanescent electromagnetic fields and can be advantageously used for on-chip optical trapping. In this work, we investigate how evanescent fields at the surface of photonic cavities can efficiently trap micro-objects such as polystyrene particles and bacteria. We study first the influence of trapped particle's size on the trapping potential and introduce an original optofluidic near-field optical microscopy technique. Then we analyze the rotational motion of trapped clusters of microparticles and investigate their possible use as microfluidic micro-tools such as integrated micro-flow vane. Eventually, we demonstrate efficient on-chip optical trapping of various kinds of bacteria.

  19. Advances on Microsized On-Chip Lithium-Ion Batteries.

    Science.gov (United States)

    Liu, Lixiang; Weng, Qunhong; Lu, Xueyi; Sun, Xiaolei; Zhang, Lin; Schmidt, Oliver G

    2017-09-27

    Development of microsized on-chip batteries plays an important role in the design of modern micro-electromechanical systems, miniaturized biomedical sensors, and many other small-scale electronic devices. This emerging field intimately correlates with the topics of rechargeable batteries, nanomaterials, on-chip microfabrication, etc. In recent years, a number of novel designs are proposed to increase the energy and power densities per footprint area, as well as other electrochemical performances of microsized lithium-ion batteries. These advances may guide the pathway for the future development of microbatteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Transcranial magnetic stimulation reveals complex cognitive control representations in the rostral frontal cortex.

    Science.gov (United States)

    Bahlmann, J; Beckmann, I; Kuhlemann, I; Schweikard, A; Münte, T F

    2015-08-06

    Convergent evidence suggests that the lateral frontal cortex is at the heart of a brain network subserving cognitive control. Recent theories assume a functional segregation along the rostro-caudal axis of the lateral frontal cortex based on differences in the degree of complexity of cognitive control. However, the functional contribution of specific rostral and caudal sub-regions remains elusive. Here we investigate the impact of disrupting rostral and caudal target regions on cognitive control processes, using Transcranial Magnetic Stimulation (TMS). Participants performed three different task-switching conditions that assessed differences in the degree of complexity of cognitive control processes, after temporally disrupting rostral, or caudal target regions, or a control region. Disrupting the rostral lateral frontal region specifically impaired behavioral performance of the most complex task-switching condition, in comparison to the caudal target region and the control region. These novel findings shed light on the neuroanatomical architecture supporting control over goal-directed behavior.

  1. Enhancement of Isometric Ankle Dorsiflexion by Automyoelectrically Controlled Functional Electrical Stimulation on Subjects with Upper Motor Neuron Lesions

    NARCIS (Netherlands)

    Thorsen, R.; Ferrarin, M.; Veltink, P.

    2002-01-01

    The objective of this study was to test myoelectrically controlled functional electrical stimulation of the same muscle (AutoMCS) on patients with either stroke or spinal cord injury. The paretic anterior tibialis (TA) muscle was stimulated with an amplitude controlled continuously by the volitional

  2. Transcranial direct current stimulation in post-stroke dysphagia: a systematic review of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Kavian Ghandehari

    2016-07-01

    Full Text Available Introduction: The aim of this research was to systematically review all the randomized controlled trials that have evaluated the effect of transcranial direct current stimulation (tDCS on post-stroke dysphagia. Methods: Three electronic databases were searched for relevant articles that were uploaded from their inception to March 2015: PubMed, Cochrane Library (Cochrane Central Register of Controlled Trials, and Scopus. All data was that was related to the location of the cerebrovascular accident (CVA, the parameters of tDCS, post-stroke time to commencement of tDCS, the stimulated hemisphere, stimulation dose, any outcome measurements, and follow-up duration were extracted and assessed. Finally, a number of observations were generated through a qualitative synthesis of the extracted data.Result: Three eligible randomized controlled trials were included in the systematic review. All three trials reported that, in comparison to a placebo, tDCS had a statistically significant effect on post-stroke dysphagia.Discussion: The results of our systematic review suggest that tDCS may represent a promising novel treatment for post-stroke dysphagia. However, to date, little is known about the optimal parameters of tDCS for relieving post-stroke dysphagia. Further studies are warranted to refine this promising intervention by exploring the optimal parameters of tDCS.Conclusion: Since brainstem swallowing centers have bilateral cortical innervations, measures that enhance cortical input and sensorimotor control of brainstem swallowing may facilitate recovery from dysphagia.

  3. On-chip optical trapping for atomic applications

    Science.gov (United States)

    Perez, Maximillian A.; Salim, Evan; Farkas, Daniel; Duggan, Janet; Ivory, Megan; Anderson, Dana

    2014-09-01

    To simplify applications that rely on optical trapping of cold and ultracold atoms, ColdQuanta is developing techniques to incorporate miniature optical components onto in-vacuum atom chips. The result is a hybrid atom chip that combines an in-vacuum micro-optical bench for optical control with an atom chip for magnetic control. Placing optical components on a chip inside of the vacuum system produces a compact system that can be targeted to specific experiments, in this case the generation of optical lattices. Applications that can benefit from this technology include timekeeping, inertial sensing, gravimetry, quantum information, and emulation of quantum many-body systems. ColdQuanta's GlasSi atom chip technology incorporates glass windows in the plane of a silicon atom chip. In conjunction with the in-vacuum micro-optical bench, optical lattices can be generated within a few hundred microns of an atom chip window through which single atomic lattice sites can be imaged with sub-micron spatial resolution. The result is a quantum gas microscope that allows optical lattices to be studied at the level of single lattice sites. Similar to what ColdQuanta has achieved with magneto-optical traps (MOTs) in its miniMOT system and with Bose- Einstein condensates (BECs) in its RuBECi(R) system, ColdQuanta seeks to apply the on-chip optical bench technology to studies of optical lattices in a commercially available, turnkey system. These techniques are currently being considered for lattice experiments in NASA's Cold Atom Laboratory (CAL) slated for flight on the International Space Station.

  4. A Novel Transcranial Magnetic Stimulator Inducing Near Rectangular Pulses with Controllable Pulse Width (cTMS)

    Science.gov (United States)

    Jalinous, Reza; Lisanby, Sarah H.

    2013-01-01

    A novel transcranial magnetic stimulation (TMS) device with controllable pulse width (PW) and near rectangular pulse shape (cTMS) is described. The cTMS device uses an insulated gate bipolar transistor (IGBT) with appropriate snubbers to switch coil currents up to 7 kA, enabling PW control from 5 μs to over 100 μs. The near-rectangular induced electric field pulses use 22–34% less energy and generate 67–72% less coil heating compared to matched conventional cosine pulses. CTMS is used to stimulate rhesus monkey motor cortex in vivo with PWs of 20 to 100 μs, demonstrating the expected decrease of threshold pulse amplitude with increasing PW. The technological solutions used in the cTMS prototype can expand functionality, and reduce power consumption and coil heating in TMS, enhancing its research and therapeutic applications. PMID:18232369

  5. Effects of Anodal Transcranial Direct Current Stimulation on Visually Guided Learning of Grip Force Control

    Directory of Open Access Journals (Sweden)

    Tamas Minarik

    2015-03-01

    Full Text Available Anodal transcranial Direct Current Stimulation (tDCS has been shown to be an effective non-invasive brain stimulation method for improving cognitive and motor functioning in patients with neurological deficits. tDCS over motor cortex (M1, for instance, facilitates motor learning in stroke patients. However, the literature on anodal tDCS effects on motor learning in healthy participants is inconclusive, and the effects of tDCS on visuo-motor integration are not well understood. In the present study we examined whether tDCS over the contralateral motor cortex enhances learning of grip-force output in a visually guided feedback task in young and neurologically healthy volunteers. Twenty minutes of 1 mA anodal tDCS were applied over the primary motor cortex (M1 contralateral to the dominant (right hand, during the first half of a 40 min power-grip task. This task required the control of a visual signal by modulating the strength of the power-grip for six seconds per trial. Each participant completed a two-session sham-controlled crossover protocol. The stimulation conditions were counterbalanced across participants and the sessions were one week apart. Performance measures comprised time-on-target and target-deviation, and were calculated for the periods of stimulation (or sham and during the afterphase respectively. Statistical analyses revealed significant performance improvements over the stimulation and the afterphase, but this learning effect was not modulated by tDCS condition. This suggests that the form of visuomotor learning taking place in the present task was not sensitive to neurostimulation. These null effects, together with similar reports for other types of motor tasks, lead to the proposition that tDCS facilitation of motor learning might be restricted to cases or situations where the motor system is challenged, such as motor deficits, advanced age, or very high task demand.

  6. Somatotopic organization of the white matter tracts underpinning motor control in humans: an electrical stimulation study.

    Science.gov (United States)

    Rech, Fabien; Herbet, Guillaume; Moritz-Gasser, Sylvie; Duffau, Hugues

    2016-09-01

    The somatotopic organization of the primary motor cortex is well documented. However, a possible somatotopy of the network involved in motor control, i.e., eliciting negative motor phenomena during electrostimulation, is unknown in humans, particularly at the subcortical level. Here, we performed electrical stimulation mapping in awake patients operated for gliomas, to study the distribution of the white matter tracts subserving movement control of the lower limb, upper limb(s), and speech. Eighteen patients underwent awake surgery for frontal low-grade gliomas, by using intraoperative subcortical electrostimulation mapping to search interference with movement of the leg, arm(s), and face. We assessed the negative motor responses and their distribution throughout the tracts located under premotor areas. The corresponding stimulation sites were reported on a standard brain template for visual analysis and between-subjects comparisons. During stimulation of the white matter underneath the dorsal premotor cortex and supplementary motor area, rostral to the corticospinal tracts, all patients experienced cessation of the movement of lower and upper limbs, of bimanual coordination, and/or speech. These subcortical sites were somatotopically distributed. Indeed, stimulation of the fibers from mesial to lateral directions and from posterior to anterior directions evoked arrest of movement of the lower limb (mesially and posteriorly), upper limb(s), and face/speech (laterally and anteriorly). There were no postoperative permanent deficits. This is the first evidence of a somatotopic organization of the white matter bundles underpinning movement control in humans. A better knowledge of the distribution of this motor control network may be helpful in neurosciences and neurosurgery.

  7. Transcranial direct current stimulation in the recovery of postural control after stroke : a pilot study

    OpenAIRE

    Saeys, Wim; Vereeck, Luc; Lafosse, Christophe; Truijen, Steven; Wuyts, Floris L.; de Heyning, van, P.H.

    2015-01-01

    Abstract: Purpose: This pilot study aimed to evaluate the effectiveness of multiple sessions of transcranial Direct Current Stimulation (tDCS) during 4 weeks on balance and gait parameters after stroke. Method: Thirty-one stroke patients were included in this randomised, double-blind, sham-controlled crossover study. The Tinetti test was used to assess functional balance and gait after stroke. Secondary measures, Rivermead Motor Assessment (RMA) and Trunk Impairment Scale (TIS), were register...

  8. A controlled trial of transcutaneous vagus nerve stimulation for the treatment of pharmacoresistant epilepsy.

    Science.gov (United States)

    Aihua, Liu; Lu, Song; Liping, Li; Xiuru, Wang; Hua, Lin; Yuping, Wang

    2014-10-01

    This study explored the efficacy and safety of transcutaneous vagus nerve stimulation (t-VNS) in patients with pharmacoresistant epilepsy. A total of 60 patients were randomly divided into two groups based on the stimulation zone: the Ramsay-Hunt zone (treatment group) and the earlobe (control group). Before and after the 12-month treatment period, all patients completed the Self-Rating Anxiety Scale (SAS), the Self-Rating Depression Scale (SDS), the Liverpool Seizure Severity Scale (LSSS), and the Quality of Life in Epilepsy Inventory (QOLIE-31). Seizure frequency was determined according to the patient's seizure diary. During our study, the antiepileptic drugs were maintained at a constant level in all subjects. After 12 months, the monthly seizure frequency was lower in the treatment group than in the control group (8.0 to 4.0; P=0.003). This reduction in seizure frequency was correlated with seizure frequency at baseline and duration of epilepsy (both P>0.05). Additionally, all patients showed improved SAS, SDS, LSSS, and QOLIE-31 scores that were not correlated with a reduction in seizure frequency. The side effects in the treatment group were dizziness (1 case) and daytime drowsiness (3 cases), which could be relieved by reducing the stimulation intensity. In the control group, compared with baseline, there were no significant changes in seizure frequency (P=0.397), SAS, SDS, LESS, or QOLIE-31. There were also no complications in this group.

  9. Microprocessor-controlled optical stimulating device to improve the gait of patients with Parkinson's disease.

    Science.gov (United States)

    Ferrarin, M; Brambilla, M; Garavello, L; Di Candia, A; Pedotti, A; Rabuffetti, M

    2004-05-01

    Different types of visual cue for subjects with Parkinson's disease (PD) produced an improvement in gait and helped some of them prevent or overcome freezing episodes. The paper describes a portable gait-enabling device (optical stimulating glasses (OSGs) that provides, in the peripheral field of view, different types of continuous optic flow (backward or forward) and intermittent stimuli synchronised with external events. The OSGs are a programmable, stand-alone, augmented reality system that can be interfaced with a PC for program set-up. It consists of a pair of non-corrective glasses, equipped with two matrixes of 70 micro light emitting diodes, one on each side, controlled by a microprocessor. Two foot-switches are used to synchronise optical stimulation with specific gait events. A pilot study was carried out on three PD patients and three controls, with different types of optic flow during walking along a fixed path. The continuous optic flow in the forward direction produced an increase in gait velocity in the PD patients (up to + 11% in average), whereas the controls had small variations. The stimulation synchronised with the swing phase, associated with an attentional strategy, produced a remarkable increase in stride length for all subjects. After prolonged testing, the device has shown good applicability and technical functionality, it is easily wearable and transportable, and it does not interfere with gait.

  10. Hormonal, functional and genetic biomarkers in controlled ovarian stimulation: tools for matching patients and protocols

    Directory of Open Access Journals (Sweden)

    Alviggi Carlo

    2012-02-01

    Full Text Available Abstract Variability in the subfertile patient population excludes the possibility of a single approach to controlled ovarian stimulation (COS covering all the requirements of a patient. Modern technology has led to the development of new drugs, treatment options and quantitative methods that can identify single patient characteristics. These could potentially be used to match patients with the right treatment options to optimise efficacy, safety and tolerability during COS. Currently, age and follicle-stimulating hormone (FSH level remain the most commonly used single patient characteristics in clinical practice. These variables only provide a basic prognosis for success and indications for standard COS treatment based on gross patient categorisation. In contrast, the anti-Müllerian hormone level appears to be an accurate predictor of ovarian reserve and response to COS, and could be used successfully to guide COS. The antral follicle count is a functional biomarker that could be useful in determining the dose of FSH necessary during stimulation and the success of treatment. Finally, in the future, genetic screening may allow an individual patient's response to stimulation during COS to be predicted based on genotype. Unfortunately, despite the predictive power of these measures, no single biomarker can stand alone as a guide to determine the best treatment option. In the future, hormonal, functional and genetic biomarkers will be used together to personalise COS.

  11. Hormonal, functional and genetic biomarkers in controlled ovarian stimulation: tools for matching patients and protocols.

    Science.gov (United States)

    Alviggi, Carlo; Humaidan, Peter; Ezcurra, Diego

    2012-02-06

    Variability in the subfertile patient population excludes the possibility of a single approach to controlled ovarian stimulation (COS) covering all the requirements of a patient. Modern technology has led to the development of new drugs, treatment options and quantitative methods that can identify single patient characteristics. These could potentially be used to match patients with the right treatment options to optimise efficacy, safety and tolerability during COS. Currently, age and follicle-stimulating hormone (FSH) level remain the most commonly used single patient characteristics in clinical practice. These variables only provide a basic prognosis for success and indications for standard COS treatment based on gross patient categorisation. In contrast, the anti-Müllerian hormone level appears to be an accurate predictor of ovarian reserve and response to COS, and could be used successfully to guide COS. The antral follicle count is a functional biomarker that could be useful in determining the dose of FSH necessary during stimulation and the success of treatment. Finally, in the future, genetic screening may allow an individual patient's response to stimulation during COS to be predicted based on genotype. Unfortunately, despite the predictive power of these measures, no single biomarker can stand alone as a guide to determine the best treatment option. In the future, hormonal, functional and genetic biomarkers will be used together to personalise COS.

  12. A microfluidic platform for controlled biochemical stimulation of twin neuronal networks.

    Science.gov (United States)

    Biffi, Emilia; Piraino, Francesco; Pedrocchi, Alessandra; Fiore, Gianfranco B; Ferrigno, Giancarlo; Redaelli, Alberto; Menegon, Andrea; Rasponi, Marco

    2012-06-01

    Spatially and temporally resolved delivery of soluble factors is a key feature for pharmacological applications. In this framework, microfluidics coupled to multisite electrophysiology offers great advantages in neuropharmacology and toxicology. In this work, a microfluidic device for biochemical stimulation of neuronal networks was developed. A micro-chamber for cell culturing, previously developed and tested for long term neuronal growth by our group, was provided with a thin wall, which partially divided the cell culture region in two sub-compartments. The device was reversibly coupled to a flat micro electrode array and used to culture primary neurons in the same microenvironment. We demonstrated that the two fluidically connected compartments were able to originate two parallel neuronal networks with similar electrophysiological activity but functionally independent. Furthermore, the device allowed to connect the outlet port to a syringe pump and to transform the static culture chamber in a perfused one. At 14 days invitro, sub-networks were independently stimulated with a test molecule, tetrodotoxin, a neurotoxin known to block action potentials, by means of continuous delivery. Electrical activity recordings proved the ability of the device configuration to selectively stimulate each neuronal network individually. The proposed microfluidic approach represents an innovative methodology to perform biological, pharmacological, and electrophysiological experiments on neuronal networks. Indeed, it allows for controlled delivery of substances to cells, and it overcomes the limitations due to standard drug stimulation techniques. Finally, the twin network configuration reduces biological variability, which has important outcomes on pharmacological and drug screening.

  13. Highly-integrated lab-on-chip system for point-of-care multiparameter analysis.

    Science.gov (United States)

    Schumacher, Soeren; Nestler, Jörg; Otto, Thomas; Wegener, Michael; Ehrentreich-Förster, Eva; Michel, Dirk; Wunderlich, Kai; Palzer, Silke; Sohn, Kai; Weber, Achim; Burgard, Matthias; Grzesiak, Andrzej; Teichert, Andreas; Brandenburg, Albrecht; Koger, Birgit; Albers, Jörg; Nebling, Eric; Bier, Frank F

    2012-02-07

    A novel innovative approach towards a marketable lab-on-chip system for point-of-care in vitro diagnostics is reported. In a consortium of seven Fraunhofer Institutes a lab-on-chip system called "Fraunhofer ivD-platform" has been established which opens up the possibility for an on-site analysis at low costs. The system features a high degree of modularity and integration. Modularity allows the adaption of common and established assay types of various formats. Integration lets the system move from the laboratory to the point-of-need. By making use of the microarray format the lab-on-chip system also addresses new trends in biomedicine. Research topics such as personalized medicine or companion diagnostics show that multiparameter analyses are an added value for diagnostics, therapy as well as therapy control. These goals are addressed with a low-cost and self-contained cartridge, since reagents, microfluidic actuators and various sensors are integrated within the cartridge. In combination with a fully automated instrumentation (read-out and processing unit) a diagnostic assay can be performed in about 15 min. Via a user-friendly interface the read-out unit itself performs the assay protocol, data acquisition and data analysis. So far, example assays for nucleic acids (detection of different pathogens) and protein markers (such as CRP and PSA) have been established using an electrochemical read-out based on redoxcycling or an optical read-out based on total internal reflectance fluorescence (TIRF). It could be shown that the assay performance within the cartridge is similar to that found for the same assay in a microtiter plate. Furthermore, recent developments are the integration of sample preparation and polymerase chain reaction (PCR) on-chip. Hence, the instrument is capable of providing heating-and-cooling cycles necessary for DNA-amplification. In addition to scientific aspects also the production of such a lab-on-chip system was part of the development since

  14. Comb Capacitor Structures for On-Chip Physical Uncloneable Function

    NARCIS (Netherlands)

    Roy, D.; Klootwijk, J.H.; Verhaegh, N.A.M.; Roosen, H.H.A.J.; Wolters, Robertus A.M.

    2009-01-01

    Planar inter-digitated comb capacitor structures are an excellent tool for on-chip capacitance measurement and evaluation of properties of coating layers with varying composition. These comb structures are easily fabricated in a single step in the last metallization layer of a standard IC process.

  15. Custom Topology Generation for Network-on-Chip

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Sparsø, Jens

    2007-01-01

    This paper compares simulated annealing and tabu search for generating custom topologies for applications with periodic behaviour executing on a network-on-chip. The approach differs from previous work by starting from a fixed mapping of IP-cores to routers and performing design space exploration...

  16. A virtual channel router for on-chip networks

    NARCIS (Netherlands)

    Kavaldjiev, Nikolay; Smit, Gerard J.M.; Jansen, Pierre G.

    2004-01-01

    This paper proposes an architecture of a virtual channel router for an on-chip network1. The router has simple dynamic arbitration which is deterministic and fair. We show that the size of the proposed router is reduced by 49% and the speed increases 1.4 times compared to a conventional virtual chan

  17. A virtual channel router for on-chip networks

    OpenAIRE

    Kavaldjiev, Nikolay; Smit, Gerard J.M.; Jansen, Pierre G.

    2004-01-01

    This paper proposes an architecture of a virtual channel router for an on-chip network1. The router has simple dynamic arbitration which is deterministic and fair. We show that the size of the proposed router is reduced by 49% and the speed increases 1.4 times compared to a conventional virtual channel router.

  18. Two Architectures for On-chip Virtual Channel Router

    NARCIS (Netherlands)

    Kavaldjiev, Nikolay; Smit, Gerard J.M.; Jansen, Pierre G.

    2004-01-01

    This paper compares the implementation results of two architectures for virtual channel router. Since the router is used for building an on-chip network, its small size is critical. Together with the total design area we provide information about the distribution of this area between the main router

  19. A Virtual Channel Router for On-chip Networks

    NARCIS (Netherlands)

    Kavaldjiev, Nikolay; Smit, Gerard J.M.; Jansen, Pierre G.

    2004-01-01

    This paper proposes an architecture of a virtual channel router for an on-chip network1. The router has simple dynamic arbitration which is deterministic and fair. We show that the size of the proposed router is reduced by 49% and the speed increases 1.4 times compared to a conventional virtual chan

  20. A Virtual Channel Router for On-chip Networks

    NARCIS (Netherlands)

    Kavaldjiev, N.K.; Smit, Gerardus Johannes Maria; Jansen, P.G.

    This paper proposes an architecture of a virtual channel router for an on-chip network1. The router has simple dynamic arbitration which is deterministic and fair. We show that the size of the proposed router is reduced by 49% and the speed increases 1.4 times compared to a conventional virtual

  1. Two Architectures for On-chip Virtual Channel Router

    NARCIS (Netherlands)

    Kavaldjiev, N.K.; Smit, Gerardus Johannes Maria; Jansen, P.G.

    2004-01-01

    This paper compares the implementation results of two architectures for virtual channel router. Since the router is used for building an on-chip network, its small size is critical. Together with the total design area we provide information about the distribution of this area between the main router

  2. On-chip separation and sensing systems for hydrodynamic chromatography

    NARCIS (Netherlands)

    Blom, M.T.

    2002-01-01

    The feasibility of on-chip analytical separations using planar hydrodynamic chromatography (HDC) in Pyrex-silicon and fused silica chips has been demonstrated. In order to sketch the analytical separations area in which the HDC chip has to operate, an introduction was given of important macro-scale

  3. Customizing and hardwiring on-chip interconnects in FPGAs

    NARCIS (Netherlands)

    Hur, J.Y.

    2011-01-01

    This thesis presents our investigations on how to efficiently utilize on-chip wires to improve network performance in reconfigurable hardware. A fieldprogrammable gate array (FPGA), as a key component in a modern reconfigurable platform, accommodates many-millions of wires and the on-demand

  4. Field Programmable Gate Arrays with Hardwired Networks on Chip

    NARCIS (Netherlands)

    Wahlah, M.A.

    2012-01-01

    Technology down-scaling and platform-based designs have enforced a number of application and architecture trends for system-on-chip (SOC) designs. A modern SOC is now a multi-functional machine that can execute a large number of complex applications by using tens or even hundreds of intellectual

  5. Inkjet printed structures for smart lab-on-chip systems

    Science.gov (United States)

    Beckert, E.; Eberhardt, R.; Pabst, Oliver; Kemper, Falk; Shu, Zhe; Tünnermann, Andreas; Perelaer, Jolke; Schubert, Ulrich; Becker, Holger

    2013-03-01

    Inkjet printing is a digital printing technique that is capable of depositing not only inks, but functional materials onto different substrates in an additive way. In this paper, applications of inkjet printed structures for microfluidic lab-on-chip systems are discussed. Such systems are promising for different chemical or biochemical analysis tasks carried out at the Point-of-Care level and therefore due to cost reasons are often fabricated from polymers. The paper discusses inkjetprinted wiring structures and electroactive polymer (EAP) actuators for use in microfluidic lab-on-chip systems. Silver and gold wirings are shown that are fabricated by printing metal nanoparticle inks onto polymer substrates. After printing the structures are sintered using argon plasma sintering, a low-temperature sintering process that is compatible with polymer substrates. The wirings consist of several electrode like structures and contact pads and feature minimum structure sizes of approximately 70 μm. They can be used for electrodes, fluid presence detectors and localized ohmic heaters in lab-on-chip systems. Based on that an all inkjet-printed EAP actuator then is discussed. Membrane-type bending actuators generate deflections of approximately 5 μm when being driven at a resonance frequency of 1.8 kHz with 110 V. Derived from that and assuming passive valves on-chip pumping rates in the range of 0.5 ml/min can be estimated.

  6. Novel on-chip spiral inductors with back hollow structure

    Science.gov (United States)

    Wang, Gang; Liu, Houfang; Li, Xiaoning; Qiu, Haochuan; Yang, Yi; Ren, Tian-Ling

    2017-01-01

    In this work, on-chip spiral inductors with back hollow structure have been prepared on the 500 μm thick silicon substrate with high resistivity (ρ > 5000Ωcm). The silicon underneath the inductor region has been completely etched by deep etching process in order to reduce the substrate eddy current losses. Several types of square spiral on-chip inductors with different metal width (w) and line spacing (s) in the case of w + s = 40μm were fabricated. The experimental results are verified by FEM simulation using HFSS software. The results show that the Q-factor and self-resonance frequency of back hollow structure inductors are both enhanced compared with the conventional inductors. Furthermore, narrower width of coils for the on-chip spiral inductors with back hollow structure can result in higher Q-factor, inductance L and self-resonance frequency, which provide some important design guides for the fabrication of the high performance on-chip inductors.

  7. Comb Capacitor Structures for On-Chip Physical Uncloneable Function

    NARCIS (Netherlands)

    Roy, D.; Klootwijk, J.H.; Verhaegh, N.A.M.; Roosen, H.H.A.J.; Wolters, R.A.M.

    2009-01-01

    Planar inter-digitated comb capacitor structures are an excellent tool for on-chip capacitance measurement and evaluation of properties of coating layers with varying composition. These comb structures are easily fabricated in a single step in the last metallization layer of a standard IC process. C

  8. A Light-Weight Statically Scheduled Network-on-Chip

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Bo; Schoeberl, Martin; Sparsø, Jens

    2012-01-01

    This paper investigates how a light-weight, statically scheduled network-on-chip (NoC) for real-time systems can be designed and implemented. The NoC provides communication channels between all cores with equal bandwidth and latency. The design is FPGA-friendly and consumes a minimum of resources...

  9. Customizing and hardwiring on-chip interconnects in FPGAs

    NARCIS (Netherlands)

    Hur, J.Y.

    2011-01-01

    This thesis presents our investigations on how to efficiently utilize on-chip wires to improve network performance in reconfigurable hardware. A fieldprogrammable gate array (FPGA), as a key component in a modern reconfigurable platform, accommodates many-millions of wires and the on-demand reconfig

  10. Thin film magnetostrictive sensor with on-chip readout

    Science.gov (United States)

    Lu, Yong

    We report the first successful integration of magnetostrictive Metglas2605S2 (Fesb{78}Sisb9Bsb{13}) thin film sensor system on silicon with high resolution capacitive readout. A deposition process for Metglas thin film has been developed to allow easy control of thin film composition. An amorphous microstructure has been achieved over a wide temperature range, and in-situ magnetic domain alignment can be accomplished at room temperature as the film is deposited. The thin film has been characterized by Inductively Coupled Plasma (ICP) analysis for composition, X-Ray Diffraction (XRD) spectrum for microstructure, magnetization measurement for domain alignment and capacitive measurement for magnetostriction. The thin film is suitable for any magnetostrictive sensor applications, in particular, for IC compatible microsensors and microactuators. We have demonstrated the subsequent process integration with IC fabrication technology. Here, the Metglas thin film has been successfully incorporated to micromechanical structures using surface micromachining with appropriate choice of sacrificial layer and low stress mechanical layers. In addition, we present the development of a high resolution capacitive readout circuit co-integrated with the sensor. The readout circuit is based on a floating gate MOSFET configuration, requiring just a single transistor and operated at DC or low frequencies. Using the prototype developed in-house, we have successfully demonstrated a resolution capability of 10sp{-17} F, this translates to a few A in terms of cantilever beam deflection of the sensor. The floating gate readout technique is readily applicable to any capacitive sensors with a need for on-chip readout. It is also an ideal in-situ test structure for on IC chip process characterization and parameter extraction.

  11. Pain management using Han's acupoint nerve stimulator combined with patient-controlled analgesia following neurosurgery A randomized case control study

    Institute of Scientific and Technical Information of China (English)

    Junming Ye; Zuyu Zhu; Cheng Huang; Jun Wei

    2008-01-01

    BACKGROUND:Han's acupoint ncwve stimulator(HANS)has been frequently used to relieve pain by promoting the central ncrvve system's release of endogenous opioid peptides through electric stimulation to the body surface.OBJECTIVE:To investigate the pain-relieving effects of HANS,combined with patient-controlled analgesia,following neurosurgery,and to observe adverse reactions and effects.DESIGN,TIME AND SETTING:A randomized centrel observation was performed at the Department of Neurology in the First Affiliated Hospital of Gannan MeScal College(Ganzhou,Jiangxi Province,China)from January 2005 to February 2006.PARTICIPANTS:Forty patients,who were selected for craniotomy and required pain relief following surgery at the Department of Neurology in the First Affiliated Hospital of Garman Medical College(China),were included in this study.METHODS:Forty patients underwent neurosurgery and were randomly divided into two groups:patient-controlled analgesia plus HANS(+HANS,n=20)and patient-controlled analgesia(-HANS,n=20).Both groups were well matched in baseline data.Automatic syringe infusion pump ZZB-150 was the product of Nantong Aipeng Medical Instruments Co.,Ltd.(China).Patient-controlled analgesia consisted of 100 mL 0.02% lappaconitine/0.02% metoclopramide.LH-402 HANS instrument was produced in Beijing(China),with a serial number of 402183.The HANS instrumentation was used to stimulate the Hegu-Laogong acupoint on one side and Jiaogan,Shenmen penetrating Shen,Waifei,Naogan penetrating Pizhixia ear acupoints on the affected side for one hour,with 2-hour intervals.The disperse-dense wave was alternating,with a 2/100 Hz frequency of dectrical stimulation.MAIN OUTCOME MEASURE:The scores of visual analogue scale and incidence of adverse reaction were observed in two groups following surgery.RESULTS:Compared with the-HANS group,the visual analogue scale scores were remarkably lower in the+HANS group six hours after surgery(P<0.01),and the incidence rate of adverse reactions

  12. Handheld analyzer with on-chip molecularly-imprinted biosensors for electrical detection of propofol in plasma samples.

    Science.gov (United States)

    Hong, Chien-Chong; Lin, Chih-Chung; Hong, Chian-Lang; Lin, Zi-Xiang; Chung, Meng-Hua; Hsieh, Pei-Wen

    2016-12-15

    This paper proposes a novel handheld analyzer with disposable lab-on-a-chip technology for the electrical detection of the anesthetic propofol in human plasma samples for clinical diagnoses. The developed on-chip biosensors are based on the conduction of molecularly imprinted polymers (MIPs) that employ label-free electrical detection techniques. Propofol in total intravenous anesthesia is widely used with a target-controlled infusion system. At present, the methods employed for detecting blood propofol concentrations in hospitals comprise high-performance liquid chromatography and ion mobility spectrometry. These conventional instruments are bulky, expensive, and difficult to access. In this study, we developed a novel plastic microfluidic biochip with an on-chip anesthetic biosensor that was characterized for the rapid detection of propofol concentrations. The experimental results revealed that the response time of the developed propofol biosensors was 25s. The specific binding of an MIP to a nonimprinted polymer (NIP) reached up to 560%. Moreover, the detection limit of the biosensors was 0.1μg/mL, with a linear detection range of 0.1-30μg/mL. The proposed disposable microfluidic biochip with an on-chip anesthetic biosensor using MIPs exhibited excellent performance in the separation and sensing of propofol molecules in the human plasma samples. Compared with large-scale conventional instruments, the developed microfluidic biochips with on-chip MIP biosensors present the advantages of a compact size, high selectivity, low cost, rapid response, and single-step detection.

  13. Artificial motor control for electrically stimulated upper limbs of plegic or paretic people

    Directory of Open Access Journals (Sweden)

    Elgison da Luz dos Santos

    Full Text Available Introduction: Functional Electrical Stimulation (FES is a technique used in the restoration and generation of movements performed by subjects with neuromuscular disorders such as spinal cord injury (SCI. The purpose of this article is to outline the state of the art and perspectives of the use of FES in artificial motor control of the upper limbs in paretic or plegic people. Methods The databases used in papers selection were Google Scholar and Capes’ Portals as well as proceedings of the Annual Conference of the International Functional Electrical Stimulation Society (IFESS. Results Approximately 85% of the reviewed studies showed FES profile with pulse duration ranging from 1 to 300 μs and modulating (burst frequency between 10 and 40 Hz. Regarding the type of electrodes, 88% of the studies employed transcutaneous electrodes. Conclusion We concluded that FES with closed-loop feedback and feedforward are the most used and most viable systems for upper limbs motor control, because they perform self-corrections slowing neuromuscular adaptation, allowing different planes and more range of movement and sensory-motor integration. One of the difficulties found in neuroprosthesis systems are electrical wires attached to the user, becoming uninteresting in relation to aesthetics and break. The future perspectives lead to a trend to miniaturization of the stimulation equipment and the availability of wireless networks, which allow the attachment of modules to other components without physical contact, and will become more attractive for daily use.

  14. A dual flow bioreactor with controlled mechanical stimulation for cartilage tissue engineering.

    Science.gov (United States)

    Spitters, Tim W G M; Leijten, Jeroen C H; Deus, Filipe D; Costa, Ines B F; van Apeldoorn, Aart A; van Blitterswijk, Clemens A; Karperien, Marcel

    2013-10-01

    In cartilage, tissue engineering bioreactors can create a controlled environment to study chondrocyte behavior under mechanical stimulation or produce chondrogenic grafts of clinically relevant size. Here we present a novel bioreactor that combines mechanical stimulation with a two compartment system through which nutrients can be supplied solely by diffusion from opposite sides of a tissue-engineered construct. This design is based on the hypothesis that creating gradients of nutrients, growth factors, and growth factor antagonists can aid in the generation of zonal tissue-engineered cartilage. Computational modeling predicted that the design facilitates the creation of a biologically relevant glucose gradient. This was confirmed by quantitative glucose measurements in cartilage explants. In this system, it is not only possible to create gradients of nutrients, but also of anabolic or catabolic factors. Therefore, the bioreactor design allows control over nutrient supply and mechanical stimulation useful for in vitro generation of cartilage constructs that can be used for the resurfacing of articulated joints or as a model for studying osteoarthritis disease progression.

  15. Package architecture and component design for an implanted neural stimulator with closed loop control.

    Science.gov (United States)

    Bjune, Caroline K; Marinis, Thomas F; Brady, Jeanne M; Moran, James; Wheeler, Jesse; Sriram, Tirunelveli S; Parks, Philip D; Widge, Alik S; Dougherty, Darin D; Eskandar, Emad N

    2015-08-01

    An implanted neural stimulator with closed loop control requires electrodes for stimulation pulses and recording neuron activity. Our system features arrays of 64 electrodes. Each electrode can be addressed through a cross bar switch, to enable it to be used for stimulation or recording. This electrode switch, a bank of low noise amplifiers with an integrated analog to digital converter, power conditioning electronics, and a communications and control gate array are co-located with the electrode array in a 14 millimeter diameter satellite package that is designed to be flush mounted in a skull burr hole. Our system features five satellite packages connected to a central hub processor-controller via ten conductor cables that terminate in a custom designed, miniaturized connector. The connector incorporates features of high reliability, military grade devices and utilizes three distinct seals to isolate the contacts from fluid permeation. The hub system is comprised of a connector header, hermetic electronics package, and rechargeable battery pack, which are mounted on and electrically interconnected by a flexible circuit board. The assembly is over molded with a compliant silicone rubber. The electronics package contains two antennas, a large coil, used for recharging the battery and a high bandwidth antenna that is used to download data and update software. The package is assembled from two machined alumina pieces, a flat base with brazed in, electrical feed through pins and a rectangular cover with rounded corners. Titanium seal rings are brazed onto these two pieces so that they can be sealed by laser welding. A third system antenna is incorporated in the flexible circuit board. It is used to communicate with an externally worn control package, which monitors the health of the system and allows both the user and clinician to control or modify various system function parameters.

  16. Comparison of a Ring On-Chip Network and a Code-Division Multiple-Access On-Chip Network

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2007-01-01

    Full Text Available Two network-on-chip (NoC designs are examined and compared in this paper. One design applies a bidirectional ring connection scheme, while the other design applies a code-division multiple-access (CDMA connection scheme. Both of the designs apply globally asynchronous locally synchronous (GALS scheme in order to deal with the issue of transferring data in a multiple-clock-domain environment of an on-chip system. The two NoC designs are compared with each other by their network structures, data transfer principles, network node structures, and their asynchronous designs. Both the synchronous and the asynchronous designs of the two on-chip networks are realized using a hardware-description language (HDL in order to make the entire designs suit the commonly used synchronous design tools and flow. The performance estimation and comparison of the two NoC designs which are based on the HDL realizations are addressed. By comparing the two NoC designs, the advantages and disadvantages of applying direct connection and CDMA connection schemes in an on-chip communication network are discussed.

  17. Effects of Dry Flotation Restricted Environmental Stimulation on Hypnotizability and Pain Control.

    Science.gov (United States)

    Darakjy, Jennifer; Barabasz, Marianne; Barabasz, Arreed

    2015-10-01

    The effects of dry flotation restricted environmental stimulation (REST) on hypnotizability and pain control were tested in lighted and unlighted conditions. Participants (N = 30, ages 18-30) were exposed to hypnosis maximizing (plateauing) experiences prior to the experiment. Participants were exposed to 6 hours of lighted REST (N = 10), 6 hours of unlighted REST (N = 10), or 6 hours of normal stimulation (N = 10). The Stanford Hypnotic Susceptibility Scale: Form C (SHSS: C) (Weitzenhoffer & Hilgard, 1962) and standardized ischemic pain tests were administered before and after the conditions and at a 2-week follow-up. Both REST groups shared significantly higher SHSS: C scores and significantly lower pain scores from pre-test to post-test and follow-up. The lighted REST group showed significantly higher SHSS: C scores and significantly lower pain scores than the unlighted REST group at post-test and follow-up. The findings supported Barabasz's (1982) theory of REST responding.

  18. Basic analytical methods for identification of erythropoiesis-stimulating agents in doping control

    Science.gov (United States)

    Postnikov, P. V.; Krotov, G. I.; Efimova, Yu A.; Rodchenkov, G. M.

    2016-02-01

    The design of new erythropoiesis-stimulating agents for clinical use necessitates constant development of methods for detecting the abuse of these substances, which are prohibited under the World Anti-Doping Code and are included in the World Anti-Doping Agency (WADA) prohibited list. This review integrates and describes systematically the published data on the key methods currently used by WADA-accredited anti-doping laboratories around the world to detect the abuse of erythropoiesis-stimulating agents, including direct methods (various polyacrylamide gel electrophoresis techniques, enzyme-linked immunosorbent assay, membrane enzyme immunoassay and mass spectrometry) and indirect methods (athlete biological passport). Particular attention is given to promising approaches and investigations that can be used to control prohibited erythropoietins in the near future. The bibliography includes 122 references.

  19. Time-scaling based sliding mode control for Neuromuscular Electrical Stimulation under uncertain relative degrees.

    Science.gov (United States)

    Oliveira, Tiago Roux; Costa, Luiz Rennó; Catunda, João Marcos Yamasaki; Pino, Alexandre Visintainer; Barbosa, William; Souza, Márcio Nogueira de

    2017-03-28

    This paper addresses the application of the sliding mode approach to control the arm movements by artificial recruitment of muscles using Neuromuscular Electrical Stimulation (NMES). Such a technique allows the activation of motor nerves using surface electrodes. The goal of the proposed control system is to move the upper limbs of subjects through electrical stimulation to achieve a desired elbow angular displacement. Since the human neuro-motor system has individual characteristics, being time-varying, nonlinear and subject to uncertainties, the use of advanced robust control schemes may represent a better solution than classical Proportional-Integral (PI) controllers and model-based approaches, being simpler than more sophisticated strategies using fuzzy logic or neural networks usually applied in this control problem. The objective is the introduction of a new time-scaling base sliding mode control (SMC) strategy for NMES and its experimental evaluation. The main qualitative advantages of the proposed controller via time-scaling procedure are its independence of the knowledge of the plant relative degree and the design/tuning simplicity. The developed sliding mode strategy allows for chattering alleviation due to the impact of the integrator in smoothing the control signal. In addition, no differentiator is applied to construct the sliding surface. The stability analysis of the closed-loop system is also carried out by using singular perturbation methods. Experimental results are conducted with healthy volunteers as well as stroke patients. Quantitative results show a reduction of 45% in terms of root mean square (RMS) error (from 5.9° to [Formula: see text] ) in comparison with PI control scheme, which is similar to that obtained in the literature.

  20. An Energy-Efficient Reconfigurable Circuit Switched Network-on-Chip

    NARCIS (Netherlands)

    Wolkotte, P.T.; Smit, Gerardus Johannes Maria; Rauwerda, G.K.; Smit, L.T.

    Network-on-Chip (NoC) is an energy-efficient on-chip communication architecture for multi-tile System-on-Chip (SoC) architectures. The SoC architecture, including its run-time software, can replace inflexible ASICs for future ambient systems. These ambient systems have to be flexible as well as

  1. A system-level multiprocessor system-on-chip modeling framework

    DEFF Research Database (Denmark)

    Virk, Kashif Munir; Madsen, Jan

    2004-01-01

    We present a system-level modeling framework to model system-on-chips (SoC) consisting of heterogeneous multiprocessors and network-on-chip communication structures in order to enable the developers of today's SoC designs to take advantage of the flexibility and scalability of network-on-chip...

  2. A System on Chip approach to enhanced learning in interdisciplinary robotics

    DEFF Research Database (Denmark)

    Sørensen, Anders Stengaard; Falsig, Simon

    2011-01-01

    p, li { white-space: pre-wrap; } To sustain interdisciplinary teaching and learning in the rapidly growing and diversifying field of robotics, we have successfully employed FPGA based System on Chip (SoC) technology to provide abstraction between high level software and low level IO/ and control...... hardware. Our approach is to provides students with a simple FPGA based framework for hardware access, and hardware I/O development, which is independent of computer platform and programming language, and enable the students to add to, or change I/O hardware in accordance with their skills. We have tested...

  3. A Joint-Coding Scheme With Crosstalk Avoidance in Network On Chip

    Directory of Open Access Journals (Sweden)

    Fen Ge

    2013-01-01

    Full Text Available The reliable transfer in Network on Chip can be guaranteed by crosstalk avoidance and error detection code. In this paper,we propose a joint coding scheme combined with crosstalk avoidance coding with error control coding. The Fibonacci numeral system is applied to satisfy the requirement of crosstalk avoidance coding, and the error detection is achieved by adding parity bits. We also implement the codec in register transfer level. Furthermore, the schemes of codec applying to fault-tolerant router are analyzed. The experimental result shows that "once encode, multiple decode" scheme outperforms other schemes in trade-o_ of delay, area and power.

  4. High vs. Low Frequency Stimulation Effects on Fine Motor Control in Chronic Hemiplegia: A Pilot Study

    Science.gov (United States)

    Doucet, Barbara M.; Griffin, Lisa

    2014-01-01

    Introduction The optimal parameters of neuromuscular electrical stimulation (NMES) for recovery of hand function following stroke are not known. This clinical pilot study examined whether higher or lower frequencies are more effective for improving fine motor control of the hand in a chronic post-stroke population. Methods A one-month, 4x/week in-home regimen of either a high frequency (40Hz) or low frequency (20Hz) NMES program was applied to the hemiplegic thenar muscles of 16 persons with chronic stroke. Participants were identified a priori as having a low level of function (LF) or a high level of function (HF). Outcome measures of strength, dexterity, and endurance were measured before and after participation in the regimen. Results LF subjects showed no significant changes with either the high or the low frequency NMES regimen. HF subjects showed significant changes in strength, dexterity and endurance. Within this group, higher frequencies of stimulation yielded strength gains and increased motor activation; lower frequencies impacted dexterity and endurance. Conclusions The results suggest that higher frequencies of stimulation could be more effective in improving strength and motor activation properties and that lower frequencies may impact coordination and endurance changes; results also indicate that persons with a higher functional level of recovery may respond more favorably to NMES regimens, but further study with larger patient groups is warranted. PMID:23893829

  5. A biological micro actuator: graded and closed-loop control of insect leg motion by electrical stimulation of muscles.

    Science.gov (United States)

    Cao, Feng; Zhang, Chao; Vo Doan, Tat Thang; Li, Yao; Sangi, Daniyal Haider; Koh, Jie Sheng; Huynh, Ngoc Anh; Bin Aziz, Mohamed Fareez; Choo, Hao Yu; Ikeda, Kazuo; Abbeel, Pieter; Maharbiz, Michel M; Sato, Hirotaka

    2014-01-01

    In this study, a biological microactuator was demonstrated by closed-loop motion control of the front leg of an insect (Mecynorrhina torquata, beetle) via electrical stimulation of the leg muscles. The three antagonistic pairs of muscle groups in the front leg enabled the actuator to have three degrees of freedom: protraction/retraction, levation/depression, and extension/flexion. We observed that the threshold amplitude (voltage) required to elicit leg motions was approximately 1.0 V; thus, we fixed the stimulation amplitude at 1.5 V to ensure a muscle response. The leg motions were finely graded by alternation of the stimulation frequencies: higher stimulation frequencies elicited larger leg angular displacement. A closed-loop control system was then developed, where the stimulation frequency was the manipulated variable for leg-muscle stimulation (output from the final control element to the leg muscle) and the angular displacement of the leg motion was the system response. This closed-loop control system, with an optimized proportional gain and update time, regulated the leg to set at predetermined angular positions. The average electrical stimulation power consumption per muscle group was 148 µW. These findings related to and demonstrations of the leg motion control offer promise for the future development of a reliable, low-power, biological legged machine (i.e., an insect-machine hybrid legged robot).

  6. A biological micro actuator: graded and closed-loop control of insect leg motion by electrical stimulation of muscles.

    Directory of Open Access Journals (Sweden)

    Feng Cao

    Full Text Available In this study, a biological microactuator was demonstrated by closed-loop motion control of the front leg of an insect (Mecynorrhina torquata, beetle via electrical stimulation of the leg muscles. The three antagonistic pairs of muscle groups in the front leg enabled the actuator to have three degrees of freedom: protraction/retraction, levation/depression, and extension/flexion. We observed that the threshold amplitude (voltage required to elicit leg motions was approximately 1.0 V; thus, we fixed the stimulation amplitude at 1.5 V to ensure a muscle response. The leg motions were finely graded by alternation of the stimulation frequencies: higher stimulation frequencies elicited larger leg angular displacement. A closed-loop control system was then developed, where the stimulation frequency was the manipulated variable for leg-muscle stimulation (output from the final control element to the leg muscle and the angular displacement of the leg motion was the system response. This closed-loop control system, with an optimized proportional gain and update time, regulated the leg to set at predetermined angular positions. The average electrical stimulation power consumption per muscle group was 148 µW. These findings related to and demonstrations of the leg motion control offer promise for the future development of a reliable, low-power, biological legged machine (i.e., an insect-machine hybrid legged robot.

  7. A Randomised Controlled Trial of Neuronavigated Repetitive Transcranial Magnetic Stimulation (rTMS) in Anorexia Nervosa.

    Science.gov (United States)

    McClelland, Jessica; Kekic, Maria; Bozhilova, Natali; Nestler, Steffen; Dew, Tracy; Van den Eynde, Frederique; David, Anthony S; Rubia, Katya; Campbell, Iain C; Schmidt, Ulrike

    2016-01-01

    Anorexia nervosa (AN) is associated with morbid fear of fatness, extreme food restriction and altered self-regulation. Neuroimaging data implicate fronto-striatal circuitry, including the dorsolateral prefrontal cortex (DLPFC). In this double-blind parallel group study, we investigated the effects of one session of sham-controlled high-frequency repetitive transcranial magnetic stimulation (rTMS) to the left DLPFC (l-DLPFC) in 60 individuals with AN. A food exposure task was administered before and after the procedure to elicit AN-related symptoms. The primary outcome measure was 'core AN symptoms', a variable which combined several subjective AN-related experiences. The effects of rTMS on other measures of psychopathology (e.g. mood), temporal discounting (TD; intertemporal choice behaviour) and on salivary cortisol concentrations were also investigated. Safety, tolerability and acceptability were assessed. Fourty-nine participants completed the study. Whilst there were no interaction effects of rTMS on core AN symptoms, there was a trend for group differences (p = 0.056): after controlling for pre-rTMS scores, individuals who received real rTMS had reduced symptoms post-rTMS and at 24-hour follow-up, relative to those who received sham stimulation. Other psychopathology was not altered differentially following real/sham rTMS. In relation to TD, there was an interaction trend (p = 0.060): real versus sham rTMS resulted in reduced rates of TD (more reflective choice behaviour). Salivary cortisol concentrations were unchanged by stimulation. rTMS was safe, well-tolerated and was considered an acceptable intervention. This study provides modest evidence that rTMS to the l-DLPFC transiently reduces core symptoms of AN and encourages prudent decision making. Importantly, individuals with AN considered rTMS to be a viable treatment option. These findings require replication in multiple-session studies to evaluate therapeutic efficacy. www.Controlled-Trials.com ISRCTN

  8. Contralaterally Controlled Functional Electrical Stimulation Improves Hand Dexterity in Chronic Hemiparesis: A Randomized Trial.

    Science.gov (United States)

    Knutson, Jayme S; Gunzler, Douglas D; Wilson, Richard D; Chae, John

    2016-10-01

    It is unknown whether one method of neuromuscular electrical stimulation for poststroke upper limb rehabilitation is more effective than another. Our aim was to compare the effects of contralaterally controlled functional electrical stimulation (CCFES) with cyclic neuromuscular electrical stimulation (cNMES). Stroke patients with chronic (>6 months) moderate to severe upper extremity hemiparesis (n=80) were randomized to receive 10 sessions/wk of CCFES- or cNMES-assisted hand opening exercise at home plus 20 sessions of functional task practice in the laboratory for 12 weeks. The task practice for the CCFES group was stimulation assisted. The primary outcome was change in Box and Block Test (BBT) score at 6 months post treatment. Upper extremity Fugl-Meyer and Arm Motor Abilities Test were also measured. At 6 months post treatment, the CCFES group had greater improvement on the BBT, 4.6 (95% confidence interval [CI], 2.2-7.0), than the cNMES group, 1.8 (95% CI, 0.6-3.0), between-group difference of 2.8 (95% CI, 0.1-5.5), P=0.045. No significant between-group difference was found for the upper extremity Fugl-Meyer (P=0.888) or Arm Motor Abilities Test (P=0.096). Participants who had the largest improvements on BBT were <2 years post stroke with moderate (ie, not severe) hand impairment at baseline. Among these, the 6-month post-treatment BBT gains of the CCFES group, 9.6 (95% CI, 5.6-13.6), were greater than those of the cNMES group, 4.1 (95% CI, 1.7-6.5), between-group difference of 5.5 (95% CI, 0.8-10.2), P=0.023. CCFES improved hand dexterity more than cNMES in chronic stroke survivors. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00891319. © 2016 American Heart Association, Inc.

  9. Contralaterally Controlled Functional Electrical Stimulation for Recovery of Elbow Extension and Hand Opening After Stroke

    Science.gov (United States)

    Knutson, Jayme S.; Harley, Mary Y.; Hisel, Terri Z.; Makowski, Nathaniel S.; Chae, John

    2014-01-01

    Objective The aims of this study were to determine whether patients with moderate-to-severe upper limb hemiplegia could use contralaterally controlled functional electrical stimulation at the arm and the hand (Arm+Hand CCFES) at home and to evaluate the feasibility of the Arm+Hand CCFES to reduce arm and hand motor impairment. Design With the Arm+Hand CCFES, the paretic elbow and hand extensors were stimulated with intensities proportional to the degree of elbow extension and hand opening, respectively, of the contralateral unimpaired side. For 1 2 wks, four participants with chronic (≥6 mos) upper limb hemiplegia received ∼7 hrs per week of self-administered home-based stimulation-mediated elbow extension and hand opening exercise plus ∼2.5 hrs per week of therapist-supervised laboratory-based stimulation-assisted functional task practice. Assessments of upper limb impairment were made at pretreatment, posttreatment, and 1 mo after treatment. Results All four participants were able to use the Arm+Hand CCFES system at home either independently or with very minimal assistance from a caregiver. All four participants had increases in the Fugl-Meyer score (1–9 points) and the Wolf Motor Function Test (0.2–0.8 points) and varying degrees of improvement in maximum hand opening, maximum elbow extension, and simultaneous elbow extension and hand opening. Conclusions The Arm+Hand CCFES can be successfully administered in stroke patients with moderate-to-severe impairment and can reduce various aspects of upper limb impairment. A larger efficacy study is warranted. PMID:24508938

  10. Developing a dynamic virtual stimulation protocol to induce linear egomotion during orthostatic posture control test

    Directory of Open Access Journals (Sweden)

    Paulo José Guimarães Da-Silva

    Full Text Available Abstract Introduction In this work, the effect of a dynamic visual stimulation (DS protocol was used to induce egomotion, the center of pressure (COP displacement response. Methods DS was developed concerning the scenario structure (chessboard-pattern floor and furniture and luminance. To move the scenario in a discrete forward (or backward direction, the furniture is expanded (or reduced and the black and white background is reversed during floor translation while the luminance is increased (or reduced by steps of 2 cd/m2. This protocol was evaluated using COP signals from 29 healthy volunteers: standing on a force platform observing the virtual scene (1.72 × 1.16 m projected 1 m ahead (visual incidence angle: θl = 81.4° and θv = 60.2°, which moves with constant velocity (2 m/s during 250 ms. A set of 100 DS was applied in random order, interspersed by a 10 s of static scene. Results The Tukey post-hoc test (p < 0.001 indicated egomotion in the same direction of DS. COP displacement increased over stimulation (8.4 ± 1.7 to 22.6 ±5.3 mm, as well as time to recover stability (4.1 ± 0.4 to 7.2 ± 0.6 s. The peak of egomotion during DSF occurred 200 ms after DSB (Wilcoxon, p = 0.002. Conclusion The dynamic configuration of this protocol establishes virtual flow effects of linear egomotion dependent on the direction of the dynamic visual stimulation. This finding indicates the potential application of the proposed virtual dynamic stimulation protocol to investigate the cortical visual evoked response in postural control studies.

  11. Control system design for electrical stimulation in upper limb rehabilitation modelling, identification and robust performance

    CERN Document Server

    Freeman, Chris

    2016-01-01

    This book presents a comprehensive framework for model-based electrical stimulation (ES) controller design, covering the whole process needed to develop a system for helping people with physical impairments perform functional upper limb tasks such as eating, grasping and manipulating objects. The book first demonstrates procedures for modelling and identifying biomechanical models of the response of ES, covering a wide variety of aspects including mechanical support structures, kinematics, electrode placement, tasks, and sensor locations. It then goes on to demonstrate how complex functional activities of daily living can be captured in the form of optimisation problems, and extends ES control design to address this case. It then lays out a design methodology, stability conditions, and robust performance criteria that enable control schemes to be developed systematically and transparently, ensuring that they can operate effectively in the presence of realistic modelling uncertainty, physiological variation an...

  12. Control of proliferation rate of N27 dopaminergic neurons using Transcranial Magnetic Stimulation orientation

    Science.gov (United States)

    Meng, Yiwen; Hadimani, Ravi; Anantharam, Vellareddy; Kanthasamy, Anumantha; Jiles, David

    2015-03-01

    Transcranial magnetic stimulation (TMS) has been used to investigate possible treatments for a variety of neurological disorders. However, the effect that magnetic fields have on neurons has not been well documented in the literature. We have investigated the effect of different orientation of magnetic field generated by TMS coils with a monophasic stimulator on the proliferation rate of N27 neuronal cells cultured in flasks and multi-well plates. The proliferation rate of neurons would increase by exposed horizontally adherent N27 cells to a magnetic field pointing upward through the neuronal proliferation layer compared with the control group. On the other hand, proliferation rate would decrease in cells exposed to a magnetic field pointing downward through the neuronal growth layer compared with the control group. We confirmed results obtained from the Trypan-blue and automatic cell counting methods with those from the CyQuant and MTS cell viability assays. Our findings could have important implications for the preclinical development of TMS treatments of neurological disorders and represents a new method to control the proliferation rate of neuronal cells.

  13. Milder ovarian stimulation for in-vitro fertilization reduces aneuploidy in the human preimplantation embryo: A randomized controlled trial

    NARCIS (Netherlands)

    E.B. Baart (Esther); E. Martini (Elena); M.J.C. Eijkemans (René); D. van Opstal (Diane); N.G.M. Beckers (Nicole); A. Verhoeff (Arie); N.S. Macklon (Nick); B.C.J.M. Fauser (Bart)

    2007-01-01

    textabstractBACKGROUND: To test whether ovarian stimulation for in-vitro fertilization (IVF) affects oocyte quality and thus chromosome segregation behaviour during meiosis and early embryo development, preimplantation genetic screening of embryos was employed in a prospective, randomized controlled

  14. THE STATE FINANCIAL CONTROL IN CONTEXT OF THE STRENGTHENING OF OPERABILITY OF BUDGETARY POLICY OF STIMULATION OF REGIONAL DEVELOPMENT

    National Research Council Canada - National Science Library

    M. Dyachenko

    2014-01-01

    In this article the essence of state financial control as an important factor of strengthening of operability of budgetary policy of stimulation of the socio-economic development of regions is disclosed...

  15. On-chip noninterference angular momentum multiplexing of broadband light.

    Science.gov (United States)

    Ren, Haoran; Li, Xiangping; Zhang, Qiming; Gu, Min

    2016-05-13

    Angular momentum division has emerged as a physically orthogonal multiplexing method in high-capacity optical information technologies. However, the typical bulky elements used for information retrieval from the overall diffracted field, based on the interference method, impose a fundamental limit toward realizing on-chip multiplexing. We demonstrate noninterference angular momentum multiplexing by using a mode-sorting nanoring aperture with a chip-scale footprint as small as 4.2 micrometers by 4.2 micrometers, where nanoring slits exhibit a distinctive outcoupling efficiency on tightly confined plasmonic modes. The nonresonant mode-sorting sensitivity and scalability of our approach enable on-chip parallel multiplexing over a bandwidth of 150 nanometers in the visible wavelength range. The results offer the possibility of ultrahigh-capacity and miniaturized nanophotonic devices harnessing angular momentum division.

  16. An on-chip diamond optical parametric oscillator

    CERN Document Server

    Hausmann, B J M; Venkataraman, V; Deotare, P; Loncar, M

    2013-01-01

    Efficient, on-chip optical nonlinear processes are of great interest for the development of compact, robust, low-power consuming systems for applications in spectroscopy, metrology, sensing and classical and quantum optical information processing. Diamond holds promise for these applications, owing to its exceptional properties. However, although significant progress has been made in the development of an integrated diamond photonics platform, optical nonlinearities in diamond have not been explored much apart from Raman processes in bulk samples. Here, we demonstrate optical parametric oscillations (OPO) via four wave mixing (FWM) in single crystal diamond (SCD) optical networks on-chip consisting of waveguide-coupled microring resonators. Threshold powers as low as 20mW are enabled by ultra-high quality factor (1*10^6) diamond ring resonators operating at telecom wavelengths, and up to 20 new wavelengths are generated from a single-frequency pump laser. We also report the inferred nonlinear refractive index...

  17. Energy Consumption Oriented Network-on-Chip Mapping Method

    Directory of Open Access Journals (Sweden)

    Feichao Wang

    2013-12-01

    Full Text Available In this paper, mapping algorithm has been mainly studied. The main work and contribution have been generalized as follows: Through the research of existing on-chip network mapping algorithm and global optimization algorithm, a multi-step mapping algorithm for low-power consumption have been designed, which is combined with the task allocation and the task scheduling. Compared with the traditional mapping algorithm, the algorithm in this paper takes the factors of task scheduling and allocation into account, mapping algorithm has three steps: task scheduling, IP core mapping and data block mapping. The simulation results show that the mapping method in this paper can effectively reduce Network-on-Chip (NoC power consumption. 

  18. An Implantable Cardiovascular Pressure Monitoring System with On-Chip Antenna and RF Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Yu-Chun Liu

    2015-08-01

    Full Text Available An implantable wireless system with on-chip antenna for cardiovascular pressure monitor is studied. The implantable device is operated in a batteryless manner, powered by an external radio frequency (RF power source. The received RF power level can be sensed and wirelessly transmitted along with blood pressure signal for feedback control of the external RF power. The integrated electronic system, consisting of a capacitance-to-voltage converter, an adaptive RF powering system, an RF transmitter and digital control circuitry, is simulated using a TSMC 0.18 μm CMOS technology. The implanted RF transmitter circuit is combined with a low power voltage-controlled oscillator resonating at 5.8 GHz and a power amplifier. For the design, the simulation model is setup using ADS and HFSS software. The dimension of the antenna is 1 × 0.6 × 4.8 mm3 with a 1 × 0.6 mm2 on-chip circuit which is small enough to place in human carotid artery.

  19. Integration of microcoils for on-chip immunosensors based on magnetic nanoparticles capture

    Directory of Open Access Journals (Sweden)

    Olivier Lefebvre

    2017-04-01

    Full Text Available Immunoassays using magnetic nanoparticles (MNP are generally performed under the control of permanent magnet close to the micro-tube of reaction. Using a magnet gives a powerful method for driving MNP but remains unreliable or insufficient for a fully integrated immunoassay on lab-on-chip. The aim of this study is to develop a novel lab-on-chip concept for high efficient immunoassays to detect ovalbumin (Biodefense model molecule with microcoils employed for trapping MNP during the biofunctionalization steps. The objectives are essentially to optimize their efficiency for biological recognition by assuring a better bioactivity (antibodies-ovalbumin, and detect small concentrations of the targeted protein (~10 pg/mL. In this work, we studied the response of immunoassays complex function of ovalbumin concentration. The impact of MNP diameter in the biografting protocol was studied and permitted to choose a convenient MNP size for efficient biorecognition. We realized different immunoassays by controlling MNP in test tube and in microfluidic device using a permanent magnet. The comparison between these two experiments allows us to highlight an improvement of the limit of detection in microfluidic conditions by controlling MNP trapping with a magnet.

  20. On-chip Fabrication of High Performance Nanostructured ZnO UV Detectors

    Science.gov (United States)

    Alenezi, Mohammad R.; Henley, Simon J.; Silva, S. R. P.

    2015-02-01

    Developing rationally controlled bottom-up device fabrication processes is essential for the achievement of high performance optimal devices. We report a controlled, seedless and site-selective hydrothermal technique to fabricate high-performance nanostructured ZnO UV-detectors directly on-chip. We demonstrate that by controlling the nanowire growth process, via tuning the experimental parameters such as the concentration of reactants and the growth time, and by introducing a refresh of the growth solution, the device structure efficiency can be enhanced to significantly improve its performance. The on-chip fabricated bridging nanosyringe ultraviolet detector demonstrates improved sensitivity (~105), nanowatts detectability, and ultrafast response-time (90 ms) and recovery-time (210 ms). The improvement in response-time and recovery-time is attributed to the unique nanowire-nanowire junction barrier dominated resistance and the direct contact between ZnO and Au electrodes. Furthermore, the enhanced sensitivity and nanowatts detectability of the bridging nanosyringe device are due to the reduction in dimensionality and ultrahigh surface-to-volume ratio. This work paves the way toward low cost, large scale, low temperature, seedless and site-selective fabrication of high performance ZnO nanowire sensors on flexible and transparent substrates.

  1. Object-Oriented System-on-Network-on-Chip Template and Implementation: H.263 Case Study

    Institute of Scientific and Technical Information of China (English)

    MA Liwei; SUN Yihe

    2008-01-01

    Network-on-chip (NoC) technology enables a new system-on-chip paradigm, the system-on-network-on-chip (SoNoC) paradigm. One of the challenges in designing application-specific networks is modeling the on-chip system behavior and determining on-chip traffic characteristics. A universal object message level model for SoNoC was defined and an object-oriented methodology was developed to imple-ment this model in hardware and software. The model supports "object to core" synthesis and "function in-voking to network" mapping. A case study of an H.263 system verifies the model and methodology. System prototypes are easily built and on-chip traffic can be observed using the SoNoC model to provide real benchmarks for on-chip network design.

  2. Performance Evaluation of CDMA Router for Network-On-Chip

    Directory of Open Access Journals (Sweden)

    Anant W. Hinganikar

    2012-06-01

    Full Text Available This paper presents the performance evaluation of router based on code division multiple access technique (CDMA for Network-on-Chip (NoC. The design is synthesized using Xilinx Virtex4 XC4VLX200 device. The functional behavior is verified using Modelsim XE III 6.2 C. The delay and throughput values are obtained for variable payload sizes. Throughput-Power and Delay-Power characteristics are also verified for NoC.

  3. Analysis and Management of Communication in On-Chip Networks

    OpenAIRE

    Jafari, Fahimeh

    2015-01-01

    Regarding the needs of low-power, high-performance embedded systems and the growing computation-intensive applications, the number of computing resources in a single chip has enormously increased. The current VLSI technology is able to support such an integration of transistors and add many computing resources such as CPU, DSP, specific IPs, etc to build a Systemon- Chip (SoC). However, interconnection between resources becomes another challenging issue which can be raised by using an on-chip...

  4. Low-cost on-chip clock jitter measurement scheme

    OpenAIRE

    Omana, Martin; Rossi, Daniele; Giaffreda, Daniele; Metra, Cecilia; Mak, T.M.; Raman, Asifur; Tam, Simon

    2014-01-01

    In this paper, we present a low-cost, on-chip clock jitter digital measurement scheme for high performance microprocessors. It enables in situ jitter measurement during the test or debug phase. It provides very high measurement resolution and accuracy, despite the possible presence of power supply noise (representing a major source of clock jitter), at low area and power costs. The achieved resolution is scalable with technology node and can in principle be increased as much as desired, at lo...

  5. Energy Consumption Oriented Network-on-Chip Mapping Method

    OpenAIRE

    Feichao Wang

    2013-01-01

    In this paper, mapping algorithm has been mainly studied. The main work and contribution have been generalized as follows: Through the research of existing on-chip network mapping algorithm and global optimization algorithm, a multi-step mapping algorithm for low-power consumption have been designed, which is combined with the task allocation and the task scheduling. Compared with the traditional mapping algorithm, the algorithm in this paper takes the factors of task scheduling and allocatio...

  6. Effects of restricted environmental stimulation: enhancement of hypnotizability for experimental and chronic pain control.

    Science.gov (United States)

    Barabasz, A F; Barabasz, M

    1989-07-01

    Enhancement of hypnotizability and pain tolerance has been demonstrated using restricted environmental stimulation therapy (REST) with university students as Ss (A. F. Barabasz, 1982). The purpose of the present study was to determine whether or not similar results could be obtained with chronic pain patients. Ss consisted of outpatients in treatment for conditions in which pain is prominent who also demonstrated low hypnotizability after repeated hypnosis plateau sessions. 2 groups of Ss were exposed to REST. Situational demand characteristics (Orne, 1962) favored an increase in hypnotizability for REST Group 1 (high demand). REST Group 2 (low demand) was exposed to situational demand characteristics designed to disguise the experimental hypothesis. 2 groups of control Ss were exposed to the same alternative demand characteristic manipulations as the experimental groups, but environmental stimulation was maintained. The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) of Weitzenhoffer and E. R. Hilgard (1962), including a posthypnotic suggestion for an anesthetic reaction, and an ischemic pain test were administered prior to treatment and again immediately following treatment. After 6 hours of REST, significant increases in SHSS:C scores were found for high-demand and low-demand experimental Ss, as well as for high-demand control Ss. No such increase was found for low-demand controls. Significant decreases in pain scores were found for both high- and low-demand experimental groups. No significant pain score decreases were found for either control group, suggesting a relatively weak effect of demand characteristics. An independent postexperimental inquiry suggested all Ss believed they received active treatments. The inquiry, conducted 10-15 days after the experiment, also revealed a majority of experimental Ss were using hypnosis on a daily basis to reduce pain with a substantial decrease in pain medication. Only 2 control Ss (highest in hypnotizability

  7. On-chip High-Voltage Generator Design

    CERN Document Server

    Tanzawa, Toru

    2013-01-01

    This book describes high-voltage generator design with switched-capacitor multiplier techniques.  The author provides various design techniques for switched-capacitor on-chip high-voltage generators, including charge pump circuits, regulators, level shifters, references, and oscillators.  Readers will see these techniques applied to system design in order to address the challenge of how the on-chip high-voltage generator is designed for Flash memories, LCD drivers, and other semiconductor devices to optimize the entire circuit area and power efficiency with a low voltage supply, while minimizing the cost.   ·         Shows readers how to design charge pump circuits with lower voltage operation, higher power efficiency, and smaller circuit area; ·         Describes comprehensive circuits and systems design of on-chip high-voltage generators; ·         Covers all the component circuit blocks, including charge pumps, pump regulators, level shifters, oscillators, and references.

  8. Delay Optimized Architecture for On-Chip Communication

    Institute of Scientific and Technical Information of China (English)

    Sheraz Anjum; Jie Chen; Pei-Pei Yue; Jian Liu

    2009-01-01

    Networks-on-chip (NoC), a new system on chip (SoC) paradigm, has become a great focus of research by many groups during the last few years. Among all the NoC architectures that have been proposed until now, 2D-Mesh has proved to be the best architecture for implementation due to its regular and simple intercon- nection structure. In this paper, we propose a new interconnect architecture called 2D-diagonal mesh (2DDgl-Mesh) for on-chip communication. The 2DDgl- Mesh is almost similar to traditional 2D-Mesh in aspects of cost, area, and implementation, but it can outperform the later in delay. The both architectures are compared by using NS-2 (a network simulator) and CINSIM (a component based interconnection simulator) under the same traffic models and parametric conditions. The results of comparison show that under the proposed architecture, the packets can almost always be routed to their destinations in less time. In addition, our archi- tecture can sometimes perform better than 2D-Mesh in drop ratio for special fixed traffic models.

  9. On-chip tunable optofluidic dye laser

    Science.gov (United States)

    Cai, Zengyan; Shen, Zhenhua; Liu, Haigang; Yue, Huan; Zou, Yun; Chen, Xianfeng

    2016-11-01

    We demonstrate a chip-scale tunable optofluidic dye laser with Au-coated fibers as microcavity. The chip is fabricated by soft lithography. When the active region is pumped, a relatively low threshold of 6.7 μJ/mm2 is realized with multimode emission due to good confinement of the cavity mirrors, long active region, as well as total reflectivity. It is easy to tune the lasing emission wavelength by changing the solvent of laser dye. In addition, the various intensity ratios of multicolor lasing can be achieved by controlling flow rates of two fluid streams carried with different dye molecules. Furthermore, the convenience in fabrication and directional lasing emission outcoupled by the fiber make the tunable optofluidic dye laser a promising underlying coherent light source in the integrated optofluidic systems.

  10. Lensless high-resolution on-chip optofluidic microscopes for Caenorhabditis elegans and cell imaging.

    Science.gov (United States)

    Cui, Xiquan; Lee, Lap Man; Heng, Xin; Zhong, Weiwei; Sternberg, Paul W; Psaltis, Demetri; Yang, Changhuei

    2008-08-05

    Low-cost and high-resolution on-chip microscopes are vital for reducing cost and improving efficiency for modern biomedicine and bioscience. Despite the needs, the conventional microscope design has proven difficult to miniaturize. Here, we report the implementation and application of two high-resolution (approximately 0.9 microm for the first and approximately 0.8 microm for the second), lensless, and fully on-chip microscopes based on the optofluidic microscopy (OFM) method. These systems abandon the conventional microscope design, which requires expensive lenses and large space to magnify images, and instead utilizes microfluidic flow to deliver specimens across array(s) of micrometer-size apertures defined on a metal-coated CMOS sensor to generate direct projection images. The first system utilizes a gravity-driven microfluidic flow for sample scanning and is suited for imaging elongate objects, such as Caenorhabditis elegans; and the second system employs an electrokinetic drive for flow control and is suited for imaging cells and other spherical/ellipsoidal objects. As a demonstration of the OFM for bioscience research, we show that the prototypes can be used to perform automated phenotype characterization of different Caenorhabditis elegans mutant strains, and to image spores and single cellular entities. The optofluidic microscope design, readily fabricable with existing semiconductor and microfluidic technologies, offers low-cost and highly compact imaging solutions. More functionalities, such as on-chip phase and fluorescence imaging, can also be readily adapted into OFM systems. We anticipate that the OFM can significantly address a range of biomedical and bioscience needs, and engender new microscope applications.

  11. On-chip immunoelectrophoresis of extracellular vesicles released from human breast cancer cells.

    Science.gov (United States)

    Akagi, Takanori; Kato, Kei; Kobayashi, Masashi; Kosaka, Nobuyoshi; Ochiya, Takahiro; Ichiki, Takanori

    2015-01-01

    Extracellular vesicles (EVs) including exosomes and microvesicles have attracted considerable attention in the fields of cell biology and medicine. For a better understanding of EVs and further exploration of their applications, the development of analytical methods for biological nanovesicles has been required. In particular, considering the heterogeneity of EVs, methods capable of measuring individual vesicles are desired. Here, we report that on-chip immunoelectrophoresis can provide a useful method for the differential protein expression profiling of individual EVs. Electrophoresis experiments were performed on EVs collected from the culture supernatant of MDA-MB-231 human breast cancer cells using a measurement platform comprising a microcapillary electrophoresis chip and a laser dark-field microimaging system. The zeta potential distribution of EVs that reacted with an anti-human CD63 (exosome and microvesicle marker) antibody showed a marked positive shift as compared with that for the normal immunoglobulin G (IgG) isotype control. Thus, on-chip immunoelectrophoresis could sensitively detect the over-expression of CD63 glycoproteins on EVs. Moreover, to explore the applicability of on-chip immunoelectrophoresis to cancer diagnosis, EVs collected from the blood of a mouse tumor model were analyzed by this method. By comparing the zeta potential distributions of EVs after their immunochemical reaction with normal IgG, and the anti-human CD63 and anti-human CD44 (cancer stem cell marker) antibodies, EVs of tumor origin circulating in blood were differentially detected in the real sample. The result indicates that the present method is potentially applicable to liquid biopsy, a promising approach to the low-invasive diagnosis of cancer.

  12. 3-Dimensional cell culture for on-chip differentiation of stem cells in embryoid body.

    Science.gov (United States)

    Kim, Choong; Lee, Kang Sun; Bang, Jae Hoon; Kim, Young Eyn; Kim, Min-Cheol; Oh, Kwang Wook; Lee, Soo Hyun; Kang, Ji Yoon

    2011-03-07

    This paper proposes a microfluidic device for the on-chip differentiation of an embryoid body (EB) formed in a microwell via 3-dimensional cultures of mouse embryonic carcinoma (EC) cells. The device adjusted the size of the EB by fluid volume, differentiated the EB by chemical treatment, and evaluated its effects in EC cells by on-chip immunostaining. A microfluidic resistance network was designed to control the size of the embryoid body. The duration time and flow rate into each microwell regulated the initial number of trapped cells in order to adjust the size of the EB. The docked cells were aggregated and formed a spherical EB on the non-adherent surface of the culture chip for 3 days. The EC cells in the EB were then differentiated into diverse cell lineages without attachment for an additional 4 days; meanwhile, retinoic acid (RA) was applied without serum to direct the cells into early neuronal lineage. On-chip immunostaining of the EB in the microwell with a neuronal marker was conducted to assess the differentiation-inducing ability of RA. The effect of RA on neuronal differentiation was analyzed with confocal microscopic images of the TuJ1 marker. The RA-treated cells expressed more neuronal markers and appeared as mature neuronal cells with long neurites. The fluorescence intensity of the TuJ1 in the RA-treated EB was twice that observed in the non-treated EB on day 5. It was demonstrated that the pre-screening of inducing chemicals on the early neuronal differentiation of EC cells in a single microfluidic chip was indeed feasible. This chip is expected to constitute a useful tool for assessing the early differentiation of ES cells without attachment, and is also expected to prove useful as an anti-cancer drug test platform for the cytotoxicity assay with cellular spheroids.

  13. On-chip immunoelectrophoresis of extracellular vesicles released from human breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Takanori Akagi

    Full Text Available Extracellular vesicles (EVs including exosomes and microvesicles have attracted considerable attention in the fields of cell biology and medicine. For a better understanding of EVs and further exploration of their applications, the development of analytical methods for biological nanovesicles has been required. In particular, considering the heterogeneity of EVs, methods capable of measuring individual vesicles are desired. Here, we report that on-chip immunoelectrophoresis can provide a useful method for the differential protein expression profiling of individual EVs. Electrophoresis experiments were performed on EVs collected from the culture supernatant of MDA-MB-231 human breast cancer cells using a measurement platform comprising a microcapillary electrophoresis chip and a laser dark-field microimaging system. The zeta potential distribution of EVs that reacted with an anti-human CD63 (exosome and microvesicle marker antibody showed a marked positive shift as compared with that for the normal immunoglobulin G (IgG isotype control. Thus, on-chip immunoelectrophoresis could sensitively detect the over-expression of CD63 glycoproteins on EVs. Moreover, to explore the applicability of on-chip immunoelectrophoresis to cancer diagnosis, EVs collected from the blood of a mouse tumor model were analyzed by this method. By comparing the zeta potential distributions of EVs after their immunochemical reaction with normal IgG, and the anti-human CD63 and anti-human CD44 (cancer stem cell marker antibodies, EVs of tumor origin circulating in blood were differentially detected in the real sample. The result indicates that the present method is potentially applicable to liquid biopsy, a promising approach to the low-invasive diagnosis of cancer.

  14. Holographic patterning of high-performance on-chip 3D lithium-ion microbatteries.

    Science.gov (United States)

    Ning, Hailong; Pikul, James H; Zhang, Runyu; Li, Xuejiao; Xu, Sheng; Wang, Junjie; Rogers, John A; King, William P; Braun, Paul V

    2015-05-26

    As sensors, wireless communication devices, personal health monitoring systems, and autonomous microelectromechanical systems (MEMS) become distributed and smaller, there is an increasing demand for miniaturized integrated power sources. Although thin-film batteries are well-suited for on-chip integration, their energy and power per unit area are limited. Three-dimensional electrode designs have potential to offer much greater power and energy per unit area; however, efforts to date to realize 3D microbatteries have led to prototypes with solid electrodes (and therefore low power) or mesostructured electrodes not compatible with manufacturing or on-chip integration. Here, we demonstrate an on-chip compatible method to fabricate high energy density (6.5 μWh cm(-2)⋅μm(-1)) 3D mesostructured Li-ion microbatteries based on LiMnO2 cathodes, and NiSn anodes that possess supercapacitor-like power (3,600 μW cm(-2)⋅μm(-1) peak). The mesostructured electrodes are fabricated by combining 3D holographic lithography with conventional photolithography, enabling deterministic control of both the internal electrode mesostructure and the spatial distribution of the electrodes on the substrate. The resultant full cells exhibit impressive performances, for example a conventional light-emitting diode (LED) is driven with a 500-μA peak current (600-C discharge) from a 10-μm-thick microbattery with an area of 4 mm(2) for 200 cycles with only 12% capacity fade. A combined experimental and modeling study where the structural parameters of the battery are modulated illustrates the unique design flexibility enabled by 3D holographic lithography and provides guidance for optimization for a given application.

  15. Transcranial direct current stimulation in the recovery of postural control after stroke: a pilot study.

    Science.gov (United States)

    Saeys, Wim; Vereeck, Luc; Lafosse, Christophe; Truijen, Steven; Wuyts, Floris L; Van De Heyning, Paul

    2015-01-01

    This pilot study aimed to evaluate the effectiveness of multiple sessions of transcranial Direct Current Stimulation (tDCS) during 4 weeks on balance and gait parameters after stroke. Thirty-one stroke patients were included in this randomised, double-blind, sham-controlled crossover study. The Tinetti test was used to assess functional balance and gait after stroke. Secondary measures, Rivermead Motor Assessment (RMA) and Trunk Impairment Scale (TIS), were registered to asses both motricity and trunk performance. All tests were administered at baseline, after 4 and 8 weeks. Patients were randomly divided into two groups. Both groups received both sixteen 20-min sessions of tDCS and sixteen 20-min sessions of Sham stimulation. Application method between groups was changed after 4 weeks. A general linear repeated measures model was used to analyse the results of our study. Results revealed an effect on the total score of the Tinetti test (p = 0.049). No significant results were obtained for the RMA (p = 0.166) and the TIS (p = 0.479). This pilot study indicates that 16 tDCS-sessions could have a beneficial effect on balance and gait in stroke patients measured with the Tinetti test. However, further research is needed to elucidate these findings. Implications for Rehabilitation Sixteen sessions of tDCS is beneficial in the recovery of postural control in stroke patients. tDCS has to be applied as soon as possible to enhance beneficial effects.

  16. Acupuncture-Point Stimulation for Postoperative Pain Control: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Xian-Liang Liu

    2015-01-01

    Full Text Available The purpose of this study was to evaluate the effectiveness of Acupuncture-point stimulation (APS in postoperative pain control compared with sham/placebo acupuncture or standard treatments (usual care or no treatment. Only randomized controlled trials (RCTs were included. Meta-analysis results indicated that APS interventions improved VAS scores significantly and also reduced total morphine consumption. No serious APS-related adverse effects (AEs were reported. There is Level I evidence for the effectiveness of body points plaster therapy and Level II evidence for body points electroacupuncture (EA, body points acupressure, body points APS for abdominal surgery patients, auricular points seed embedding, manual auricular acupuncture, and auricular EA. We obtained Level III evidence for body points APS in patients who underwent cardiac surgery and cesarean section and for auricular-point stimulation in patients who underwent abdominal surgery. There is insufficient evidence to conclude that APS is an effective postoperative pain therapy in surgical patients, although the evidence does support the conclusion that APS can reduce analgesic requirements without AEs. The best level of evidence was not adequate in most subgroups. Some limitations of this study may have affected the results, possibly leading to an overestimation of APS effects.

  17. 60 GHz system-on-chip (SoC) with built-in memory and an on-chip antenna

    KAUST Repository

    Ghaffar, Farhan A.

    2014-04-01

    A novel 60 GHz transmitter SoC with an on-chip antenna and integrated memory in CMOS 65 nm technology is presented in this paper. This highly integrated transmitter design can support a data rate of 2 GBPS with a transmission range of 1 m. The transmitter consists of a fundamental frequency 60 GHz PLL which covers the complete ISM band. The modulator following the PLL can support both BPSK and OOK modulation schemes. Both stored data on the integrated memory or directly from an external source can be transmitted. A tapered slot on chip antenna is integrated with the power amplifier to complete the front end of the transmitter design. Size of the complete transmitter with on-chip antenna is only 1.96 mm × 1.96 mm. The core circuits consume less than 100 mW of power. The high data rate capability of the design makes it extremely suitable for bandwidth hungry applications such as unencrypted HD video streaming and transmission.

  18. Defining the neural fulcrum for chronic vagus nerve stimulation: implications for integrated cardiac control.

    Science.gov (United States)

    Ardell, Jeffrey L; Nier, Heath; Hammer, Matthew; Southerland, E Marie; Ardell, Christopher L; Beaumont, Eric; KenKnight, Bruce H; Armour, J Andrew

    2017-09-01

    The evoked cardiac response to bipolar cervical vagus nerve stimulation (VNS) reflects a dynamic interaction between afferent mediated decreases in central parasympathetic drive and suppressive effects evoked by direct stimulation of parasympathetic efferent axons to the heart. The neural fulcrum is defined as the operating point, based on frequency-amplitude-pulse width, where a null heart rate response is reproducibly evoked during the on-phase of VNS. Cardiac control, based on the principal of the neural fulcrum, can be elicited from either vagus. Beta-receptor blockade does not alter the tachycardia phase to low intensity VNS, but can increase the bradycardia to higher intensity VNS. While muscarinic cholinergic blockade prevented the VNS-induced bradycardia, clinically relevant doses of ACE inhibitors, beta-blockade and the funny channel blocker ivabradine did not alter the VNS chronotropic response. While there are qualitative differences in VNS heart control between awake and anaesthetized states, the physiological expression of the neural fulcrum is maintained. Vagus nerve stimulation (VNS) is an emerging therapy for treatment of chronic heart failure and remains a standard of therapy in patients with treatment-resistant epilepsy. The objective of this work was to characterize heart rate (HR) responses (HRRs) during the active phase of chronic VNS over a wide range of stimulation parameters in order to define optimal protocols for bidirectional bioelectronic control of the heart. In normal canines, bipolar electrodes were chronically implanted on the cervical vagosympathetic trunk bilaterally with anode cephalad to cathode (n = 8, 'cardiac' configuration) or with electrode positions reversed (n = 8, 'epilepsy' configuration). In awake state, HRRs were determined for each combination of pulse frequency (2-20 Hz), intensity (0-3.5 mA) and pulse widths (130-750 μs) over 14 months. At low intensities and higher frequency VNS, HR increased during the

  19. Does electrical stimulation reduce spasticity after stroke? A randomized controlled study.

    Science.gov (United States)

    Bakhtiary, Amir H; Fatemy, Elham

    2008-05-01

    To investigate the therapeutic effect of electrical stimulation on plantarflexor spasticity in stroke patients. A randomized controlled clinical trial study. Rehabilitation clinic of Semnan University of Medical Sciences. Forty stroke patients (aged from 42 to 65 years) with ankle plantarflexor spasticity. Fifteen minutes of inhibitory Bobath techniques were applied to one experimental group and a combination of 9 minutes of electrical stimulation on the dorsiflexor muscles and inhibitory Bobath techniques was applied to another group for 20 sessions daily. Passive ankle joint dorsiflexion range of motion, dorsiflexion strength test, plantarflexor muscle tone by Modified Ashworth Scale and soleus muscle H-reflex. The mean change of passive ankle joint dorsiflexion in the combination therapy group was 11.4 (SD 4.79) degrees versus 6.1 (SD 3.09) degrees, which was significantly higher (P = 0.001). The mean change of plantarflexor muscle tonicity measured by the Modified Ashworth Scale in the combination therapy group was -1.6 (SD 0.5) versus -1.1 (SD 0.31) in the Bobath group (P = 0.001). Dorsiflexor muscle strength was also increased significantly (P = 0.04) in the combination therapy group (0.7 +/- 0.37) compared with the Bobath group (0.4 +/- 0.23). However, no significant change in the amplitude of H-reflex was found between combination therapy (-0.41 +/- 0.29) and Bobath (-0.3 +/- 0.28) groups. Therapy combining Bobath inhibitory technique and electrical stimulation may help to reduce spasticity effectively in stroke patients.

  20. Effects of STN and GPi deep brain stimulation on impulse control disorders and dopamine dysregulation syndrome.

    Directory of Open Access Journals (Sweden)

    Sarah J Moum

    Full Text Available OBJECTIVE: Impulse control disorders (ICDs and dopamine dysregulation syndrome (DDS are important behavioral problems that affect a subpopulation of patients with Parkinson's disease (PD and typically result in markedly diminished quality of life for patients and their caregivers. We aimed to investigate the effects of subthalamic nucleus (STN and internal globus pallidus (GPi deep brain stimulation (DBS on ICD/DDS frequency and dopaminergic medication usage. METHODS: A retrospective chart review was performed on 159 individuals who underwent unilateral or bilateral PD DBS surgery in either STN or GPi. According to published criteria, pre- and post-operative records were reviewed to categorize patients both pre- and post-operatively as having ICD, DDS, both ICD and DDS, or neither ICD nor DDS. Group differences in patient demographics, clinical presentations, levodopa equivalent dose (LED, and change in diagnosis following unilateral/bilateral by brain target (STN or GPi DBS placement were examined. RESULTS: 28 patients met diagnostic criteria for ICD or DDS pre- or post-operatively. ICD or DDS classification did not differ by GPi or STN target stimulation. There was no change in DDS diagnosis after unilateral or bilateral stimulation. For ICD, diagnosis resolved in 2 of 7 individuals after unilateral or bilateral DBS. Post-operative development of these syndromes was significant; 17 patients developed ICD diagnoses post-operatively with 2 patients with pre-operative ICD developing DDS post-operatively. CONCLUSIONS: Unilateral or bilateral DBS did not significantly treat DDS or ICD in our sample, even though a few cases of ICD resolved post-operatively. Rather, our study provides preliminary evidence that DDS and ICD diagnoses may emerge following DBS surgery.

  1. Concept and approach of human signal-molecular-profiling database: a pilot study on depression using Lab-on-chips.

    Science.gov (United States)

    Dong, Tao; Zhao, Xinyan; Yang, Zhaochu

    2013-01-01

    Signal molecular profiling (SMP) in serum can reveal abundant medical information about the human body. The construction of a human signal-molecular-profiling database (HSMPD) will greatly prompt the research of medical science. However, some challenges hinder the construction of HSMPD. A promising strategy is proposed to provide a convenient way for the establishment of HSMPD. Firstly, a low-cost and high-throughput tool for measuring SMP should be developed and standardized. When the SMP-oriented tools were accepted by most hospitals worldwide, SMP information will be decoded by a cloud-based system and stored into the online database naturally. In the pilot study, an ultrasensitive Lab-on-chips (LOC) device was developed as a specific tool for SMP. Clinical serum samples from 10 women within 4 weeks of giving birth, including 2 patients with postpartum depression were studied by the LOC devices, since accumulating evidence has indicated that hormones and cytokines in patients with mood disorders are abnormal. HSMPD may be applied to diagnose depression in the future. Here, five kinds of signal molecules were quantified on the devices, namely, tumor necrosis factor-alpha (TNF-α), thyroid-stimulating hormone (TSH), interleukin (IL)-2, IL-6 and IL-8. The preliminary results showed that the concentrations of IL-2 and IL-8 in the depression group may be higher than those in the control group, whereas the other kinds of signal molecules did not change significantly. Although the correlations are not enough to induct any diagnostic criterion, the SMP-oriented tool was verified. The results also indicated that the strategy to establish HSMPD is conceivable.

  2. A Randomized Double-Blind Sham-Controlled Study of Transcranial Direct Current Stimulation for Treatment-Resistant Major Depression

    Directory of Open Access Journals (Sweden)

    Daniel eBlumberger

    2012-08-01

    Full Text Available Objectives: Transcranial direct current stimulation (tDCS has demonstrated some efficacy in treatment-resistant major depression (TRD. The majority of previous controlled studies have used anodal stimulation to the left dorsolateral prefrontal cortex (DLPFC and a control location such as the supraorbital region on for the cathode. Several open label studies have suggested effectiveness from anodal stimulation to the left DLPFC combined with cathodal stimulation to the right DLPFC. Thus, this study evaluated the efficacy of tDCS using anodal stimulation to the left DLPFC and cathodal stimulation to the right DLPFC compared to sham tDCS. Methods: Subjects between the ages of 18 and 65 were recruited from a tertiary care university hospital. Twenty-four subjects with TRD and a 17-item Hamilton Depression Rating Scale (HDRS greater than 21 were randomized to receive tDCS or sham tDCS. The rates of remission were compared between the two treatment groups.Results: The remission rates did not differ significantly between the two groups using an intention to treat analysis. More subjects in the active tDCS group had failed a course of electroconvulsive therapy in the current depressive episode. Side effects did not differ between the two groups and in general the treatment was very well tolerated. Conclusion: Anodal stimulation to the left DLPFC and cathodal stimulation to the right DLPFC was not efficacious in TRD. However, a number of methodological limitations warrant caution in generalizing from this study. Ongoing, controlled studies should provide further clarification on the efficacy of this stimulation configuration in TRD.

  3. A Randomised Controlled Trial of Neuronavigated Repetitive Transcranial Magnetic Stimulation (rTMS in Anorexia Nervosa.

    Directory of Open Access Journals (Sweden)

    Jessica McClelland

    Full Text Available Anorexia nervosa (AN is associated with morbid fear of fatness, extreme food restriction and altered self-regulation. Neuroimaging data implicate fronto-striatal circuitry, including the dorsolateral prefrontal cortex (DLPFC.In this double-blind parallel group study, we investigated the effects of one session of sham-controlled high-frequency repetitive transcranial magnetic stimulation (rTMS to the left DLPFC (l-DLPFC in 60 individuals with AN. A food exposure task was administered before and after the procedure to elicit AN-related symptoms.The primary outcome measure was 'core AN symptoms', a variable which combined several subjective AN-related experiences. The effects of rTMS on other measures of psychopathology (e.g. mood, temporal discounting (TD; intertemporal choice behaviour and on salivary cortisol concentrations were also investigated. Safety, tolerability and acceptability were assessed.Fourty-nine participants completed the study. Whilst there were no interaction effects of rTMS on core AN symptoms, there was a trend for group differences (p = 0.056: after controlling for pre-rTMS scores, individuals who received real rTMS had reduced symptoms post-rTMS and at 24-hour follow-up, relative to those who received sham stimulation. Other psychopathology was not altered differentially following real/sham rTMS. In relation to TD, there was an interaction trend (p = 0.060: real versus sham rTMS resulted in reduced rates of TD (more reflective choice behaviour. Salivary cortisol concentrations were unchanged by stimulation. rTMS was safe, well-tolerated and was considered an acceptable intervention.This study provides modest evidence that rTMS to the l-DLPFC transiently reduces core symptoms of AN and encourages prudent decision making. Importantly, individuals with AN considered rTMS to be a viable treatment option. These findings require replication in multiple-session studies to evaluate therapeutic efficacy.www.Controlled

  4. Controlling stimulated Raman scattering by two-color light in inertial confinement fusion

    Science.gov (United States)

    Liu, Z. J.; Chen, Y. H.; Zheng, C. Y.; Cao, L. H.; Li, B.; Xiang, J.; Hao, L.; Lan, K.

    2017-08-01

    A method is proposed to control the stimulated Raman scattering in the inertial confinement fusion by using auxiliary 2ω light to suppress the stimulated Raman scattering of the 3ω light. In this scheme, inverse bremsstrahlung absorption and parametric instabilities in the 2ω light increase the electron temperature and the plasma-density fluctuation, thus preventing the development of Raman scattering of the 3ω light. This scheme is successfully demonstrated by both one-dimensional kinetic simulations and two-dimensional radiative hydrodynamic simulations. The one-dimensional Vlasov results show that the time-averaged transmissivity of the 3ω light increases from 0.75 to 0.95 under certain conditions. Results obtained using the particle-in-cell method with Monte Carlo collisions show that the electron temperature is greatly increased with the increasing intensity of the 2ω light. The two-dimensional radiative hydrodynamic simulation results show that the electron temperature increases from 3.2 keV to 3.5 keV, and the time-averaged backscattering level decreases from 0.28 to 0.1 in the presence of the auxiliary 2ω light.

  5. Transcranial Magnetic Stimulation to Address Mild Cognitive Impairment in the Elderly: A Randomized Controlled Study

    Science.gov (United States)

    Drumond Marra, Hellen Livia; Myczkowski, Martin Luiz; Maia Memória, Cláudia; Arnaut, Débora; Leite Ribeiro, Philip; Sardinha Mansur, Carlos Gustavo; Lancelote Alberto, Rodrigo; Boura Bellini, Bianca; Alves Fernandes da Silva, Adriano; Tortella, Gabriel; Ciampi de Andrade, Daniel; Teixeira, Manoel Jacobsen; Forlenza, Orestes Vicente; Marcolin, Marco Antonio

    2015-01-01

    Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique with potential to improve memory. Mild cognitive impairment (MCI), which still lacks a specific therapy, is a clinical syndrome associated with increased risk of dementia. This study aims to assess the effects of high-frequency repetitive TMS (HF rTMS) on everyday memory of the elderly with MCI. We conducted a double-blinded randomized sham-controlled trial using rTMS over the left dorsolateral prefrontal cortex (DLPFC). Thirty-four elderly outpatients meeting Petersen's MCI criteria were randomly assigned to receive 10 sessions of either active TMS or sham, 10 Hz rTMS at 110% of motor threshold, 2,000 pulses per session. Neuropsychological assessment at baseline, after the last session (10th) and at one-month follow-up, was applied. ANOVA on the primary efficacy measure, the Rivermead Behavioural Memory Test, revealed a significant group-by-time interaction (p = 0.05), favoring the active group. The improvement was kept after one month. Other neuropsychological tests were heterogeneous. rTMS at 10 Hz enhanced everyday memory in elderly with MCI after 10 sessions. These findings suggest that rTMS might be effective as a therapy for MCI and probably a tool to delay deterioration. PMID:26160997

  6. Transcranial Magnetic Stimulation to Address Mild Cognitive Impairment in the Elderly: A Randomized Controlled Study

    Directory of Open Access Journals (Sweden)

    Hellen Livia Drumond Marra

    2015-01-01

    Full Text Available Transcranial magnetic stimulation (TMS is a noninvasive brain stimulation technique with potential to improve memory. Mild cognitive impairment (MCI, which still lacks a specific therapy, is a clinical syndrome associated with increased risk of dementia. This study aims to assess the effects of high-frequency repetitive TMS (HF rTMS on everyday memory of the elderly with MCI. We conducted a double-blinded randomized sham-controlled trial using rTMS over the left dorsolateral prefrontal cortex (DLPFC. Thirty-four elderly outpatients meeting Petersen’s MCI criteria were randomly assigned to receive 10 sessions of either active TMS or sham, 10 Hz rTMS at 110% of motor threshold, 2,000 pulses per session. Neuropsychological assessment at baseline, after the last session (10th and at one-month follow-up, was applied. ANOVA on the primary efficacy measure, the Rivermead Behavioural Memory Test, revealed a significant group-by-time interaction p=0.05, favoring the active group. The improvement was kept after one month. Other neuropsychological tests were heterogeneous. rTMS at 10 Hz enhanced everyday memory in elderly with MCI after 10 sessions. These findings suggest that rTMS might be effective as a therapy for MCI and probably a tool to delay deterioration.

  7. Geniposide regulates glucose-stimulated insulin secretion possibly through controlling glucose metabolism in INS-1 cells.

    Directory of Open Access Journals (Sweden)

    Jianhui Liu

    Full Text Available Glucose-stimulated insulin secretion (GSIS is essential to the control of metabolic fuel homeostasis. The impairment of GSIS is a key element of β-cell failure and one of causes of type 2 diabetes mellitus (T2DM. Although the KATP channel-dependent mechanism of GSIS has been broadly accepted for several decades, it does not fully describe the effects of glucose on insulin secretion. Emerging evidence has suggested that other mechanisms are involved. The present study demonstrated that geniposide enhanced GSIS in response to the stimulation of low or moderately high concentrations of glucose, and promoted glucose uptake and intracellular ATP levels in INS-1 cells. However, in the presence of a high concentration of glucose, geniposide exerted a contrary role on both GSIS and glucose uptake and metabolism. Furthermore, geniposide improved the impairment of GSIS in INS-1 cells challenged with a high concentration of glucose. Further experiments showed that geniposide modulated pyruvate carboxylase expression and the production of intermediates of glucose metabolism. The data collectively suggest that geniposide has potential to prevent or improve the impairment of insulin secretion in β-cells challenged with high concentrations of glucose, likely through pyruvate carboxylase mediated glucose metabolism in β-cells.

  8. MALT1 Protease Activity Controls the Expression of Inflammatory Genes in Keratinocytes upon Zymosan Stimulation.

    Science.gov (United States)

    Schmitt, Anja; Grondona, Paula; Maier, Tabea; Brändle, Marc; Schönfeld, Caroline; Jäger, Günter; Kosnopfel, Corinna; Eberle, Franziska C; Schittek, Birgit; Schulze-Osthoff, Klaus; Yazdi, Amir S; Hailfinger, Stephan

    2016-04-01

    The protease activity of the paracaspase mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1) plays an important role in antigen receptor-mediated lymphocyte activation by controlling the activity of the transcription factor nuclear factor-κB and is thus essential for the expression of inflammatory target genes. MALT1 is not only present in cells of the hematopoietic lineage, but is ubiquitously expressed. Here we report that stimulation with zymosan or Staphylococcus aureus induced MALT1 protease activity in human primary keratinocytes. Inhibition of the Src family of kinases or novel protein kinase C isoforms as well as silencing of CARMA2 or BCL10 interfered with activation of MALT1 protease. Silencing or inhibition of MALT1 protease strongly decreased the expression of important inflammatory genes such as TNFα, IL-17C, CXCL8 and HBD-2. MALT1-inhibited cells were unable to mount an antimicrobial response upon zymosan stimulation or phorbolester/ionomycin treatment, demonstrating a central role of MALT1 protease activity in keratinocyte immunity and suggesting MALT1 as a potential target in inflammatory skin diseases.

  9. A control study of muscle force recovery in hemiparetic patients during treatment with functional electrical stimulation.

    Science.gov (United States)

    Merletti, R; Zelaschi, F; Latella, D; Galli, M; Angeli, S; Sessa, M B

    1978-01-01

    A group of forty-nine hemiparetic patients with limited emotional, communication and sensibility involvement and with recent lesion of cerebrovascular aetiology was randomly divided into two groups of twenty-four and twenty-five subjects. Both groups received traditional physiotherapy treatment for one hour/day, one group received twenty min/day of peroneal nerve stimulation. The maximum voluntary dorsal flexion moments of the ankle joint of the affected and non affected extremities were measured with an isometric brace twice a week for one month and for both groups. The recovery of moment in the stimulated group turned out to be about three times greater than in the control group and considerably less dependent upon age, time from lesion, initial value, side of lesion. Three patients using a peroneal brace at home as an assisting device were again evaluated two months later and a further improvement was observed. This work gives statistical support to previous observations based on very few cases and provides a statistically reliable answer concerning the entity of FES induced recovery of muscle force in hemiparetic subjects.

  10. A wirelessly controlled implantable LED system for deep brain optogenetic stimulation

    Directory of Open Access Journals (Sweden)

    Mark A. Rossi

    2015-02-01

    Full Text Available In recent years optogenetics has rapidly become an essential technique in neuroscience. Its temporal and spatial specificity, combined with efficacy in manipulating neuronal activity, are especially useful in studying the behavior of awake behaving animals. Conventional optogenetics, however, requires the use of lasers and optic fibers, which can place considerable restrictions on behavior. Here we combined a wirelessly controlled interface and small implantable light-emitting diode (LED that allows flexible and precise placement of light source to illuminate any brain area. We tested this wireless LED system in vivo, in transgenic mice expressing channelrhodopsin-2 in striatonigral neurons expressing D1-like dopamine receptors. In all mice tested, we were able to elicit movements reliably. The frequency of twitches induced by high power stimulation is proportional to the frequency of stimulation. At lower power, contraversive turning was observed. Moreover, the implanted LED remains effective over 50 days after surgery, demonstrating the long-term stability of the light source. Our results show that the wireless LED system can be used to manipulate neural activity chronically in behaving mice without impeding natural movements.

  11. Three-dimensional object-oriented modeling of the stomach for the purpose of microprocessor-controlled functional stimulation.

    Science.gov (United States)

    Rashev, Peter Z; Bowes, Kenneth L; Mintchev, Martin P

    2002-12-01

    Three-dimensional (3-D) object-oriented models are needed for optimizing gastric electrical stimulation by performing virtual computer experiments. The aim of the study was to create a 3-D object-oriented electromechanical model of the stomach in vivo for the purpose of microprocessor controlled functional stimulation. The stomach was modeled using coaxial truncated conoids as objects. The strength of an external stimulating electric field generated by circumferentially implanted wire electrodes is related to artificial neurogenic and myogenic control of smooth muscle depolarization and contraction. Variation of the field strength modulates the frequency and concentration of acetylcholine release, as well as the transmembrane voltage of the muscle cells. Mechanical response of the stimulated tissue was quantified by two parametric functions of the electric field strength representing the relative contractile force and geometrical displacement of the gastric surface. Data from previously conducted canine experiments were used to test the validity of the model. The model was applied to simulate contractions with different positions, orientation and number of the circumferentially implanted stimulating electrodes. The model combined most of the existing theoretical and experimental findings concerning functional gastric stimulation and can be utilized as a flexible tool for virtual medical tests involving external high-frequency (50 Hz) neural stimulation.

  12. Functional Neuromuscular Stimulation Controlled by Surface Electromyographic Signals Produced by the Volitional Activation of the Same Muscle:

    DEFF Research Database (Denmark)

    Sennels, Søren; Fin, Biering-Sørensen; Andersen, Ole Trier

    1997-01-01

    Using the voluntary EMG as a control signal for the stimulation of the same muscle necessitates elimination of stimulus artifacts and the muscle response caused by the stimulation. The stimulus artifacts are easily eliminated by shutting down the amplifier during stimulation. The muscle response...... is a non-stationary signal, therefore an adaptive linear prediction filter is proposed. The filter is derived and tested for three filter lengths on both simulated and real data. The performance is compared with a conventional fixed comb filter. The simulations indicate that the adaptive filter...

  13. Compact Electrochemical System Using On-Chip Sensor Electrodes and Integrated Devices

    Science.gov (United States)

    Yamazaki, Tomoyuki; Ikeda, Takaaki; Ishida, Makoto; Sawada, Kazuaki

    2011-04-01

    We report a compact electrochemical sensing system to implement cyclic voltammetry. This type of sensor needs a working electrode, counter electrode, and reference electrode, all of which were integrated on a single chip. The electrochemical system also needs a potentiostat and an input voltage-generating circuit, which were developed using on-chip active devices and a few discrete passive components. This is the first sensor system incorporating electrode-side input voltage generation for electrochemical measurements using an on-chip operational amplifier, which replaces a bulky external voltage controller. A continuous cyclic voltammetry measurement was conducted with a well-studied ferricyanide solution to demonstrate the operation of the intelligent sensor chip. A clear peak was observed and linearity to the target chemical concentration was obtained between the peak height and concentration of the ferricyanide solution. With potential for mass production and small size, this sensor chip could be the best candidate to realize point-of-care testing. This sensor chip is a milestone of a fully integrated electrochemical sensor chip.

  14. Dynamics of semiconductor microring lasers subject to on-chip filtered optical feedback

    Science.gov (United States)

    Khoder, Mulham; Friart, Gaetan; Danckaert, Jan; Erneux, Thomas; Van der Sande, Guy; Verschaffelt, Guy

    2016-04-01

    Tunable laser diodes are needed in a range of applications including wavelength division multiplexing, optical instrument testing, optical sensing and tera hertz generation. In this work, we investigate the stability of lasers which use filtered optical feedback for wavelength tuning. We investigate experimentally the dynamics induced by this on-chip filtered optical feedback. In this study, we choose to use a compact device which combines a semiconductor ring laser with on-chip filtered optical feedback to achieve wavelength tunability. The filtered optical feedback is realized by employing two arrayed waveguide gratings to split/recombine light into different wavelength channels. Semiconductor optical amplifiers are placed in the feedback loop in order to control the feedback of each wavelength channel independently. Experimental observations show that the stability of the clockwise and counterclockwise propagation modes depends on the feedback strength. Experiments also show that for a specific range of the feedback strength, anti-phase oscillations in the intensity of the clockwise and counterclockwise propagating modes can be induced. These oscillations could not be seen in the same semiconductor ring laser without filtered optical feedback. We investigate how the frequency and the amplitude of these oscillations change under the effect of filtered optical feedback. We also discuss how these anti-phase oscillations can be suppressed by properly choosing the feedback strength.

  15. Looking to the future of organs-on-chips: interview with Professor John Wikswo.

    Science.gov (United States)

    Wikswo, John P

    2017-06-01

    John Wikswo talks to Francesca Lake, Managing Editor: John is the founding Director of the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE). He is also the Gordon A Cain University Professor; a B learned Professor of Living State Physics; and a Professor of Biomedical Engineering, Molecular Physiology and Biophysics, and Physics. John earned his PhD in physics at Stanford University (CA, USA). After serving as a Research Fellow in Cardiology at Stanford, he joined the Department of Physics and Astronomy at Vanderbilt University (TN, USA), where he went on to make the first measurement of the magnetic field of an isolated nerve. He founded VIIBRE at Vanderbilt in 2001 in order to foster and enhance interdisciplinary research in the biophysical sciences, bioengineering and medicine. VIIBRE efforts have led to the development of devices integral to organ-on-chip research. He is focusing on the neurovascular unit-on-a-chip, heart-on-a-chip, a missing organ microformulator, and microfluidic pumps and valves to control and analyze organs-on-chips.

  16. SEMICONDUCTOR INTEGRATED CIRCUITS: A full on-chip CMOS low-dropout voltage regulator with VCCS compensation

    Science.gov (United States)

    Leisheng, Gao; Yumei, Zhou; Bin, Wu; Jianhua, Jiang

    2010-08-01

    A full on-chip CMOS low-dropout (LDO) voltage regulator with high PSR is presented. Instead of relying on the zero generated by the load capacitor and its equivalent series resistance, the proposed LDO generates a zero by voltage-controlled current sources for stability. The compensating capacitor for the proposed scheme is only 0.18 pF, which is much smaller than the capacitor of the conventional compensation scheme. The full on-chip LDO was fabricated in commercial 0.35 μm CMOS technology. The active chip area of the LDO (including the bandgap voltage reference) is 400 × 270 μm2. Experimental results show that the PSR of the LDO is -58.7 dB at a frequency of 10 Hz and -20 dB at a frequency of 1 MHz. The proposed LDO is capable of sourcing an output current up to 50 mA.

  17. Comparison of the effects of 60 nm and 96 nm thick patterned permalloy thin films on the performance of on-chip spiral inductors

    Science.gov (United States)

    Pulijala, Vasu; Syed, Azeemuddin

    2016-12-01

    In our earlier work it was shown that the 60 nm domain patterned Permalloy, incorporated on on-chip spiral inductors, gave better performance at frequencies greater than 5 GHz compared to the bulk Permalloy incorporated inductors, and the control structure. In this paper we compare the effects of 60 nm and 96 nm thick domain patterned Permalloy thin films, on the performance of on-chip spiral inductors. Experimental results show that the 60 nm thick both bulk and patterned Permalloys provide more improvement in inductance and quality factor of inductors, compared to that of 96 nm.

  18. EEG-Based Asynchronous BCI Controls Functional Electrical Stimulation in a Tetraplegic Patient

    Directory of Open Access Journals (Sweden)

    Müller-Putz Gernot R

    2005-01-01

    Full Text Available The present study reports on the use of an EEG-based asynchronous (uncued, user-driven brain-computer interface (BCI for the control of functional electrical stimulation (FES. By the application of FES, noninvasive restoration of hand grasp function in a tetraplegic patient was achieved. The patient was able to induce bursts of beta oscillations by imagination of foot movement. These beta oscillations were recorded in a one EEG-channel configuration, bandpass filtered and squared. When this beta activity exceeded a predefined threshold, a trigger for the FES was generated. Whenever the trigger was detected, a subsequent switching of a grasp sequence composed of 4 phases occurred. The patient was able to grasp a glass with the paralyzed hand completely on his own without additional help or other technical aids.

  19. Assessing trichloromethane formation and control in algal-stimulated waters amended with nitrogen and phosphorus.

    Science.gov (United States)

    Mash, Clinton A; Winston, Byron A; Meints Ii, David A; Pifer, Ashley D; Scott, J Thad; Zhang, Wen; Fairey, Julian L

    2014-05-01

    Nitrogen (N) and phosphorus (P) enrichments can stimulate algal growth in drinking water sources, which can cause increased production of disinfection byproduct (DBP) precursors. However, the effect of systematic N and P enrichments on DBP formation and control has not been adequately studied. In this work, we enriched samples from a drinking water source - sampled on April 5, May 30, and August 19, 2013 - with N and P to stimulate algal growth at N : P ratios covering almost five orders of magnitude (0.2-4429). To simulate DBP-precursor removal processes at drinking water treatment plants (DWTPs), the samples were treated with ClO2 followed by alum coagulation prior to free chlorine addition to assess the DBP formation potential (FP). Trichloromethane (TCM) was the predominant DBP formed and the TCMFP was the highest at intermediate N : P molar ratios (∼10 to 50), which corresponded with the peak in algal biomass, as measured by chlorophyll-a (Chl-a). Algal biomass was P-limited throughout the study period, and co-limited by N for the August 19 sampling set. The differences in TCMFP between the raw and treated waters decreased with increasing P amendment, indicating that ClO2 and alum coagulation became less effective for TCM precursor removal as algal biomass increased. This study highlights the impact of nutrient enrichments on TCM formation and control and has implications for nutrient management strategies related to source water protection and for DWTPs that use source waters increasingly enriched with N and P.

  20. Individual Cognitive Stimulation Therapy for dementia (iCST: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Orrell Martin

    2012-09-01

    Full Text Available Abstract Background Improving the quality of care for people with dementia and their carers has become a national priority in many countries. Cognitive Stimulation Therapy (CST groups can be beneficial in improving cognition and quality of life for people with dementia. The aim of the current study is to develop and evaluate a home-based individual Cognitive Stimulation Therapy (iCST programme for people with dementia which can be delivered by their family carer. Methods This multi-centre, pragmatic randomised controlled trial (RCT will compare the effectiveness and cost-effectiveness of iCST for people with dementia with a treatment as usual control group. The intervention consists of iCST sessions delivered by a carer for 30 minutes, 3 times a week over 25 weeks. For people with dementia the primary outcome measures are cognition assessed by the ADAS-Cog, and quality of life assessed by QoL-AD. For carers, quality of life using the SF-12 is the primary outcome measure. Using a 5% significance level, comparison of 306 participants will yield 80% power to detect an effect size of 0.35 for cognition as measured by the ADAS-Cog, and quality of life as measured by the QoL-AD. Quality of life for the carer will be measured using the SF-12. The trial will include a cost-effectiveness analysis from a public sector perspective. Discussion The UK Department of Health has recently stressed that improving access to psychological therapies is a national priority, but many people with dementia are unable to access psychological interventions. The development of a home-based individual version of CST will provide an easy to use, widely available therapy package that will be evaluated for effectiveness and cost-effectiveness in a multi centre RCT.

  1. A Limb Action Detector Enabling People with Multiple Disabilities to Control Environmental Stimulation through Limb Action with a Nintendo Wii Remote Controller

    Science.gov (United States)

    Shih, Ching-Hsiang; Chang, Man-Ling; Shih, Ching-Tien

    2010-01-01

    This study assessed whether two persons with multiple disabilities would be able to control environmental stimulation using limb action with a Nintendo Wii Remote Controller and a newly developed limb action detection program (LADP, i.e., a new software program that turns a Wii Remote Controller into a precise limb action detector). This study was…

  2. Effect of Rhythmic Auditory Stimulation on Controlling Stepping Cadence of Individuals with Mental Retardation and Cerebral Palsy

    Science.gov (United States)

    Varsamis, Panagiotis; Staikopoulos, Konstantinos; Kartasidou, Lefkothea

    2012-01-01

    One of the purposes of Rhythmic Auditory Stimulation (RAS) is to improve the control of dysfunctional movement patterns. This study aimed to extend the line of research by focussing on secondary students with mental retardation and cerebral palsy. According to the study's assumption, cadence can be controlled through a stable and low signal…

  3. Efficacy of Asparagus recemosus (Satavar in stimulating follicular growth and ovulation in anovulatory infertility: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Sana Fatima Majeedi

    2016-02-01

    Conclusions: The effect of test drug was comparable with that of control drug in stimulating follicular growth and ovulation, though the drug was not as effective as control drug to achieve conception. [Int J Reprod Contracept Obstet Gynecol 2016; 5(2.000: 310-316

  4. On-chip integrated lasers for biophotonic applications

    DEFF Research Database (Denmark)

    Mappes, Timo; Wienhold, Tobias; Bog, Uwe

    Meeting the need of biomedical users, we develop disposable Lab-on-a-Chip systems based on commercially available polymers. We are combining passive microfluidics with active optical elements on-chip by integrating multiple solid-state and liquid-core lasers. While covering a wide range of laser...... emission wavelengths, the chips have the size of microscope cover slips and use optical and fluidic interconnects only. Here, we present our latest realizations of integrated optofluidic lasers using whispering gallery mode or distributed feedback laser cavities....

  5. On-chip photonic interconnects a computer architect's perspective

    CERN Document Server

    Nitta, Christopher J; Akella, Venkatesh

    2013-01-01

    As the number of cores on a chip continues to climb, architects will need to address both bandwidth and power consumption issues related to the interconnection network. Electrical interconnects are not likely to scale well to a large number of processors for energy efficiency reasons, and the problem is compounded by the fact that there is a fixed total power budget for a die, dictated by the amount of heat that can be dissipated without special (and expensive) cooling and packaging techniques. Thus, there is a need to seek alternatives to electrical signaling for on-chip interconnection appli

  6. A VLSI System-on-Chip for Particle Detectors

    CERN Document Server

    AUTHOR|(CDS)2078019

    In this thesis I present a System-on-Chip (SoC) I designed to oer a self- contained, compact data acquisition platform for micromegas detector mon- itoring. I carried on my work within the RD-51 collab oration of CERN. With a companion ADC, my architecture is capable to acquire the signal from a detector electro de, pro cess the data and p erform monitoring tests. The SoC is built around on a custom 8-bit micropro cessor with internal mem- ory resources and emb eds the p eripherals to b e interf...

  7. Multicore systems on-chip practical software/hardware design

    CERN Document Server

    Abdallah, Abderazek Ben

    2013-01-01

    System on chips designs have evolved from fairly simple unicore, single memory designs to complex heterogeneous multicore SoC architectures consisting of a large number of IP blocks on the same silicon. To meet high computational demands posed by latest consumer electronic devices, most current systems are based on such paradigm, which represents a real revolution in many aspects in computing.The attraction of multicore processing for power reduction is compelling. By splitting a set of tasks among multiple processor cores, the operating frequency necessary for each core can be reduced, allowi

  8. Advancing Software Development for a Multiprocessor System-on-Chip

    Directory of Open Access Journals (Sweden)

    Stephen Bique

    2007-06-01

    Full Text Available A low-level language is the right tool to develop applications for some embedded systems. Notwithstanding, a high-level language provides a proper environment to develop the programming tools. The target device is a system-on-chip consisting of an array of processors with only local communication. Applications include typical streaming applications for digital signal processing. We describe the hardware model and stress the advantages of a flexible device. We introduce IDEA, a graphical integrated development environment for an array. A proper foundation for software development is a UML and standard programming abstractions in object-oriented languages.

  9. Two-photon tomography using on-chip quantum walks

    CERN Document Server

    Titchener, James; Sukhorukov, Andrey

    2016-01-01

    We present a conceptual approach to quantum tomography based on first expanding a quantum state across extra degrees of freedom and then exploiting the introduced sparsity to perform reconstruction. We formulate its application to photonic circuits, and show that measured spatial photon correlations at the output of a specially tailored discrete-continuous quantum-walk can enable full reconstruction of any two-photon spatially entangled and mixed state at the input. This approach does not require any tunable elements, so is well suited for integration with on-chip superconducting photon detectors.

  10. Compact models for nanophotonic structures and on-chip interconnects

    Science.gov (United States)

    Alam, Mehboob

    Over the last few years, scaling in deep submicron technologies has shifted the paradigm from device-dominated to interconnect-dominated design methodology. Consequently, there is an increasing interest towards the miniaturization of the guiding medium in nanoscale integrated circuits by exploring plasmon-based waveguides to alleviate the scaling issues associated with today's copper interconnect. In this thesis, we seek short and long-term solutions of on-chip interconnect by developing accurate compact models of on-chip interconnects and impedance characterization of nanophotonic structures. The developed system models are compact and accurate over the operating frequency range and the adopted approach have provided many critical insights and produced many important results. This thesis first presents a new modeling strategy that represents the nanostructure by its equivalent impedance. By applying either quasistatic approximation or separately solving for voltage and current for dominant mode, we reduce the field problem to a circuit problem. The impedance expressed in terms of circuit components is dependent on the material constant as well as the operating frequency. The modeling methodology is successfully applied to nanoparticles and oscillating nanosphere. The proposed model characterizes plasmon resonance in these nanostructures, thereby providing basic building block to develop spice models of complex plasmon-based waveguide for sub-wavelength propagation. We also presented several techniques to develop compact models of on-chip interconnects and passive components for accurate estimation of power, noise and delay of high speed integrated circuits. The automated method generates reduced order models that are accurate across either a narrow or a wide-range of frequencies. The proposed methods are based on Krylov subspace method with interpolation points dynamically selected using either spline based algorithm or discrete wavelet transform. Narrow and

  11. Anodal Transcranial Direct Current Stimulation Shows Minimal, Measure-Specific Effects on Dynamic Postural Control in Young and Older Adults: A Double Blind, Sham-Controlled Study.

    Science.gov (United States)

    Craig, Chesney E; Doumas, Michail

    2017-01-01

    We investigated whether stimulating the cerebellum and primary motor cortex (M1) using transcranial direct current stimulation (tDCS) could affect postural control in young and older adults. tDCS was employed using a double-blind, sham-controlled design, in which young (aged 18-35) and older adults (aged 65+) were assessed over three sessions, one for each stimulatory condition-M1, cerebellar and sham. The effect of tDCS on postural control was assessed using a sway-referencing paradigm, which induced platform rotations in proportion to the participant's body sway, thus assessing sensory reweighting processes. Task difficulty was manipulated so that young adults experienced a support surface that was twice as compliant as that of older adults, in order to minimise baseline age differences in postural sway. Effects of tDCS on postural control were assessed during, immediately after and 30 minutes after tDCS. Additionally, the effect of tDCS on corticospinal excitability was measured by evaluating motor evoked potentials using transcranial magnetic stimulation immediately after and 30 minutes after tDCS. Minimal effects of tDCS on postural control were found in the eyes open condition only, and this was dependent on the measure assessed and age group. For young adults, stimulation had only offline effects, as cerebellar stimulation showed higher mean power frequency (MPF) of sway 30 minutes after stimulation. For older adults, both stimulation conditions delayed the increase in sway amplitude witnessed between blocks one and two until stimulation was no longer active. In conclusion, despite tDCS' growing popularity, we would caution researchers to consider carefully the type of measures assessed and the groups targeted in tDCS studies of postural control.

  12. Habituation to galvanic vestibular stimulation for analysis of postural control abilities in gymnasts.

    Science.gov (United States)

    Balter, Susan G T; Stokroos, Robert J; Akkermans, Ellen; Kingma, Herman

    2004-08-05

    The possible correlation between postural control abilities in gymnasts and the sensitivity for and the degree of short-term habituation to galvanic vestibular stimulation (GVS) was studied. Seven balance trained young girls (Dutch National Junior Gymnasts Championship) versus seven non-trained girls and twenty-five women underwent computer-controlled GVS using a monaural continuous 1-cosinusoidal stimulus of 0.5 Hz and 2 mA, repeated three times on each side [Balter, Stokroos, Boumans, Kingma, Acta Otolaryngol. (in press); Balter, Stokroos, Eterman, Paredis, Orbons, Kingma, Acta Otolaryngol. (in press)]. Results showed that mean total galvanic-induced body sway (GBS) gain was significantly lower in the trained and untrained girls compared to the adult women (P habituation to GVS (learning abilities), however, showed no significant differences between the three groups. We suggest that the superior balance control in professional gymnasts is primarily achieved through motor training and not by learning abilities or a higher sensitivity of the vestibular system [Neurosci. Lett. 225 (1998) 155].

  13. Microsoft Kinect-Based Artificial Perception System for Control of Functional Electrical Stimulation Assisted Grasping

    Directory of Open Access Journals (Sweden)

    Matija Štrbac

    2014-01-01

    Full Text Available We present a computer vision algorithm that incorporates a heuristic model which mimics a biological control system for the estimation of control signals used in functional electrical stimulation (FES assisted grasping. The developed processing software acquires the data from Microsoft Kinect camera and implements real-time hand tracking and object analysis. This information can be used to identify temporal synchrony and spatial synergies modalities for FES control. Therefore, the algorithm acts as artificial perception which mimics human visual perception by identifying the position and shape of the object with respect to the position of the hand in real time during the planning phase of the grasp. This artificial perception used within the heuristically developed model allows selection of the appropriate grasp and prehension. The experiments demonstrate that correct grasp modality was selected in more than 90% of tested scenarios/objects. The system is portable, and the components are low in cost and robust; hence, it can be used for the FES in clinical or even home environment. The main application of the system is envisioned for functional electrical therapy, that is, intensive exercise assisted with FES.

  14. Microsoft kinect-based artificial perception system for control of functional electrical stimulation assisted grasping.

    Science.gov (United States)

    Strbac, Matija; Kočović, Slobodan; Marković, Marko; Popović, Dejan B

    2014-01-01

    We present a computer vision algorithm that incorporates a heuristic model which mimics a biological control system for the estimation of control signals used in functional electrical stimulation (FES) assisted grasping. The developed processing software acquires the data from Microsoft Kinect camera and implements real-time hand tracking and object analysis. This information can be used to identify temporal synchrony and spatial synergies modalities for FES control. Therefore, the algorithm acts as artificial perception which mimics human visual perception by identifying the position and shape of the object with respect to the position of the hand in real time during the planning phase of the grasp. This artificial perception used within the heuristically developed model allows selection of the appropriate grasp and prehension. The experiments demonstrate that correct grasp modality was selected in more than 90% of tested scenarios/objects. The system is portable, and the components are low in cost and robust; hence, it can be used for the FES in clinical or even home environment. The main application of the system is envisioned for functional electrical therapy, that is, intensive exercise assisted with FES.

  15. Safety and feasibility of transcranial direct current stimulation in pediatric hemiparesis: randomized controlled preliminary study.

    Science.gov (United States)

    Gillick, Bernadette T; Feyma, Tim; Menk, Jeremiah; Usset, Michelle; Vaith, Amy; Wood, Teddi Jean; Worthington, Rebecca; Krach, Linda E

    2015-03-01

    Transcranial direct current stimulation (tDCS) is a form of noninvasive brain stimulation that has shown improved adult stroke outcomes. Applying tDCS in children with congenital hemiparesis has not yet been explored. The primary objective of this study was to explore the safety and feasibility of single-session tDCS through an adverse events profile and symptom assessment within a double-blind, randomized placebo-controlled preliminary study in children with congenital hemiparesis. A secondary objective was to assess the stability of hand and cognitive function. A double-blind, randomized placebo-controlled pretest/posttest/follow-up study was conducted. The study was conducted in a university pediatric research laboratory. Thirteen children, ages 7 to 18 years, with congenital hemiparesis participated. Adverse events/safety assessment and hand function were measured. Participants were randomly assigned to either an intervention group or a control group, with safety and functional assessments at pretest, at posttest on the same day, and at a 1-week follow-up session. An intervention of 10 minutes of 0.7 mA tDCS was applied to bilateral primary motor cortices. The tDCS intervention was considered safe if there was no individual decline of 25% or group decline of 2 standard deviations for motor evoked potentials (MEPs) and behavioral data and no report of adverse events. No major adverse events were found, including no seizures. Two participants did not complete the study due to lack of MEP and discomfort. For the 11 participants who completed the study, group differences in MEPs and behavioral data did not exceed 2 standard deviations in those who received the tDCS (n=5) and those in the control group (n=6). The study was completed without the need for stopping per medical monitor and biostatisticial analysis. A limitation of the study was the small sample size, with data available for 11 participants. Based on the results of this study, tDCS appears to be safe

  16. The control of neural cell-to-cell interactions through non-contact electrical field stimulation using graphene electrodes.

    Science.gov (United States)

    Heo, Chaejeong; Yoo, Jeongwan; Lee, Siyoung; Jo, Areum; Jung, Susie; Yoo, Hyosun; Lee, Young Hee; Suh, Minah

    2011-01-01

    Electric field stimulation has become one of the most promising therapies for a variety of neurological diseases. However, the safety and effectiveness of the stimulator are critical in determining the outcome. Because there are few safe and effective in vivo and/or in vitro stimulator devices, we demonstrate a method that allows for non-contact electric field stimulation with a specific strength that is able to control cell-to-cell interaction in vitro. Graphene, a form of graphite, and polyethylene terephthalate (PET) was used to create a non-cytotoxic in vitro graphene/PET film stimulator. A transient non-contact electric field was produced by charge-balanced biphasic stimuli through the graphene/PET film electrodes and applied to cultured neural cells. We found that weak electric field stimulation (pulse duration of 10 s) as low as 4.5 mV/mm for 32 min was particularly effective in shaping cell-to-cell interaction. Under weak electric field stimulation, we observed a significant increase in the number of cells forming new cell-to-cell couplings and in the number of cells strengthening existing cell-to-cell couplings. The underlying mechanism of the altered cellular interactions may be related to an altered regulation of the endogenous cytoskeletal proteins fibronectin, actin, and vinculin. In conclusion, this technique may open a new therapeutic approach for augmenting cell-to-cell coupling in cell transplantation therapy in the central nervous system. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Can transcranial direct current stimulation enhance performance of myoelectric control for multifunctional prosthesis?

    Science.gov (United States)

    Pan, Lizhi; Zhang, Dingguo; Duan, Renquan; Zhu, Xiangyang

    2014-01-01

    Pattern recognition based myoelectric control has been studied by many researchers. However, the classification accuracy was pretty low for amputees towards multifunctional prosthesis control in practice. In this work, a novel method of transcranial direct current stimulation (tDCS) which can modulate brain activity was used to enhance performance for myoelectric prosthesis control. The pilot study was conducted on three able-bodied subjects and one transradial amputee. Surface electromyography (EMG) signals were acquired from both arms when performing eleven hand and wrist motions in pre-tDCS and post-tDCS sessions. Time domain (TD) features and linear discriminant analysis (LDA) classifier were adopted to process EMG. For the non-dominant hand of the healthy subjects, active anodal tDCS of the contralateral primary motor cortex was able to significantly improve average classification accuracy by 3.82% (p 0.05). For amputated (phantom) hand of the amputee, active anodal tDCS was able to significantly improve average classification accuracy by 12.56%, while sham tDCS could not have such effect. For the dominant hand and intact hand, the average classification accuracies were stable and not significantly improved using either active tDCS or sham tDCS. The results show that tDCS is a powerful noninvasive method to modulate brain function and enhance EMG classification performance especially for the amputated hand towards multifunctional prosthesis control. The method proposed has a huge potential to promote EMG pattern recognition based control scheme to clinical application.

  18. The type of GnRH analogue used during controlled ovarian stimulation influences early embryo developmental kinetics

    DEFF Research Database (Denmark)

    Muñoz, Manuel; Cruz, María; Humaidan, Peter

    2013-01-01

    OBJECTIVE: To explore if the GnRH analogue used for controlled ovarian stimulation (COS) and the ovulation triggering factor (GnRH agonist+hCG triggering versus GnRH antagonist+GnRH agonist triggering) affect embryo development and kinetics. STUDY DESIGN: In a retrospective cohort study in the In......OBJECTIVE: To explore if the GnRH analogue used for controlled ovarian stimulation (COS) and the ovulation triggering factor (GnRH agonist+hCG triggering versus GnRH antagonist+GnRH agonist triggering) affect embryo development and kinetics. STUDY DESIGN: In a retrospective cohort study...... in the Instituto Valenciano de Infertilidad (IVI) Alicante and the Instituto Universitario-IVI Valencia, Spain, 2817 embryos deriving from 400 couples undergoing oocyte donation were analysed. After controlled ovarian stimulation and IVF/intracytoplamic sperm injection, the timing of embryonic cleavages...

  19. An integrated lab-on-chip for rapid identification and simultaneous differentiation of tropical pathogens

    National Research Council Canada - National Science Library

    Tan, Jeslin J L; Capozzoli, Monica; Sato, Mitsuharu; Watthanaworawit, Wanitda; Ling, Clare L; Mauduit, Marjorie; Malleret, Benoît; Grüner, Anne-Charlotte; Tan, Rosemary; Nosten, François H; Snounou, Georges; Rénia, Laurent; Ng, Lisa F P

    2014-01-01

    .... In this study, a microfluidic lab-on-chip integrating multiplex molecular amplification and DNA microarray hybridization was developed for simultaneous detection and species differentiation of 26...

  20. Microfluidics-Based Lab-on-Chip Systems in DNA-Based Biosensing: An Overview

    Directory of Open Access Journals (Sweden)

    Sabo Wada Dutse

    2011-05-01

    Full Text Available Microfluidics-based lab-on-chip (LOC systems are an active research area that is revolutionising high-throughput sequencing for the fast, sensitive and accurate detection of a variety of pathogens. LOCs also serve as portable diagnostic tools. The devices provide optimum control of nanolitre volumes of fluids and integrate various bioassay operations that allow the devices to rapidly sense pathogenic threat agents for environmental monitoring. LOC systems, such as microfluidic biochips, offer advantages compared to conventional identification procedures that are tedious, expensive and time consuming. This paper aims to provide a broad overview of the need for devices that are easy to operate, sensitive, fast, portable and sufficiently reliable to be used as complementary tools for the control of pathogenic agents that damage the environment.

  1. Microfluidics-based lab-on-chip systems in DNA-based biosensing: an overview.

    Science.gov (United States)

    Dutse, Sabo Wada; Yusof, Nor Azah

    2011-01-01

    Microfluidics-based lab-on-chip (LOC) systems are an active research area that is revolutionising high-throughput sequencing for the fast, sensitive and accurate detection of a variety of pathogens. LOCs also serve as portable diagnostic tools. The devices provide optimum control of nanolitre volumes of fluids and integrate various bioassay operations that allow the devices to rapidly sense pathogenic threat agents for environmental monitoring. LOC systems, such as microfluidic biochips, offer advantages compared to conventional identification procedures that are tedious, expensive and time consuming. This paper aims to provide a broad overview of the need for devices that are easy to operate, sensitive, fast, portable and sufficiently reliable to be used as complementary tools for the control of pathogenic agents that damage the environment.

  2. On-chip coherent conversion of photonic quantum entanglement between different degrees of freedom.

    Science.gov (United States)

    Feng, Lan-Tian; Zhang, Ming; Zhou, Zhi-Yuan; Li, Ming; Xiong, Xiao; Yu, Le; Shi, Bao-Sen; Guo, Guo-Ping; Dai, Dao-Xin; Ren, Xi-Feng; Guo, Guang-Can

    2016-06-20

    In the quantum world, a single particle can have various degrees of freedom to encode quantum information. Controlling multiple degrees of freedom simultaneously is necessary to describe a particle fully and, therefore, to use it more efficiently. Here we introduce the transverse waveguide-mode degree of freedom to quantum photonic integrated circuits, and demonstrate the coherent conversion of a photonic quantum state between path, polarization and transverse waveguide-mode degrees of freedom on a single chip. The preservation of quantum coherence in these conversion processes is proven by single-photon and two-photon quantum interference using a fibre beam splitter or on-chip beam splitters. These results provide us with the ability to control and convert multiple degrees of freedom of photons for quantum photonic integrated circuit-based quantum information process.

  3. On-chip coherent conversion of photonic quantum entanglement between different degrees of freedom

    Science.gov (United States)

    Feng, Lan-Tian; Zhang, Ming; Zhou, Zhi-Yuan; Li, Ming; Xiong, Xiao; Yu, Le; Shi, Bao-Sen; Guo, Guo-Ping; Dai, Dao-Xin; Ren, Xi-Feng; Guo, Guang-Can

    2016-01-01

    In the quantum world, a single particle can have various degrees of freedom to encode quantum information. Controlling multiple degrees of freedom simultaneously is necessary to describe a particle fully and, therefore, to use it more efficiently. Here we introduce the transverse waveguide-mode degree of freedom to quantum photonic integrated circuits, and demonstrate the coherent conversion of a photonic quantum state between path, polarization and transverse waveguide-mode degrees of freedom on a single chip. The preservation of quantum coherence in these conversion processes is proven by single-photon and two-photon quantum interference using a fibre beam splitter or on-chip beam splitters. These results provide us with the ability to control and convert multiple degrees of freedom of photons for quantum photonic integrated circuit-based quantum information process. PMID:27321821

  4. On-chip dual-comb based on quantum cascade laser frequency combs

    Energy Technology Data Exchange (ETDEWEB)

    Villares, G., E-mail: gustavo.villares@phys.ethz.ch; Wolf, J.; Kazakov, D.; Süess, M. J.; Beck, M.; Faist, J., E-mail: jfaist@phys.ethz.ch [Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich (Switzerland); Hugi, A. [IRsweep GmbH, CH-8093 Zürich (Switzerland)

    2015-12-21

    Dual-comb spectroscopy is emerging as an appealing application of mid-infrared frequency combs for high-resolution molecular spectroscopy, as it leverages on the unique coherence properties of frequency combs. Here, we present an on-chip dual-comb source based on mid-infrared quantum cascade laser frequency combs. Control of the combs repetition and offset frequencies is obtained by integrating micro-heaters next to each laser. We show that a full control of the dual-comb system is possible, by measuring a multi-heterodyne beating corresponding to an optical bandwidth of 32 cm{sup −1} centered at 1330 cm{sup −1} (7.52 μm), demonstrating that this device represents a critical step towards compact dual-comb systems.

  5. On-Chip Reconfigurable Hardware Accelerators for Popcount Computations

    Directory of Open Access Journals (Sweden)

    Valery Sklyarov

    2016-01-01

    Full Text Available Popcount computations are widely used in such areas as combinatorial search, data processing, statistical analysis, and bio- and chemical informatics. In many practical problems the size of initial data is very large and increase in throughput is important. The paper suggests two types of hardware accelerators that are (1 designed in FPGAs and (2 implemented in Zynq-7000 all programmable systems-on-chip with partitioning of algorithms that use popcounts between software of ARM Cortex-A9 processing system and advanced programmable logic. A three-level system architecture that includes a general-purpose computer, the problem-specific ARM, and reconfigurable hardware is then proposed. The results of experiments and comparisons with existing benchmarks demonstrate that although throughput of popcount computations is increased in FPGA-based designs interacting with general-purpose computers, communication overheads (in experiments with PCI express are significant and actual advantages can be gained if not only popcount but also other types of relevant computations are implemented in hardware. The comparison of software/hardware designs for Zynq-7000 all programmable systems-on-chip with pure software implementations in the same Zynq-7000 devices demonstrates increase in performance by a factor ranging from 5 to 19 (taking into account all the involved communication overheads between the programmable logic and the processing systems.

  6. On-chip inductor above dummy metal patterns

    Science.gov (United States)

    Hsu, Heng-Ming; Hsieh, Ming-Ming

    2008-07-01

    This work characterizes the on-chip inductor above dummy metals in CMOS technology. Since the dummy pattern influences the sheet resistance in chemical-mechanical planarization (CMP) process strongly [Schindler G, Steinlesberger G, Engelhardt M, Steinhögl W. Electrical characterization of copper interconnects with end-of-roadmap feature sizes. Solid-State Electron 2003;47:1233-36; Smith S, Walton AJ, Ross AWS, Bodammer GKH, Stevenson JTM. Evaluation of sheet resistance and electrical line width measurement techniques for copper damascene interconnect. IEEE Trans Semicond Manuf 2002;15:214-22.], three test structures are fabricated to compare the inductor performances in this paper. The measurements show that the Q value degrades 15.3% and self-resonance frequency decreases 9.5% in device with dummy metal pattern. Accordingly, an equivalent circuit is proposed to analyze this behavior, the results show that the insulator capacitor plays a key role in performance degradation. Result of this study quantifies the effect of on-chip inductor above dummy pattern.

  7. On-Chip Correlator for Passive Wireless SAW Multisensor Systems

    Directory of Open Access Journals (Sweden)

    Liqiang Xie

    2016-01-01

    Full Text Available For decoding the asynchronous superposition of response signals from different sensors, it is a challenge to achieve correlation in a code division multiplexing (CDM based passive wireless surface acoustic wave (SAW multisensor system. Therefore, an on-chip correlator scheme is developed in this paper. In contrast to conventional CDM-based systems, this novel scheme enables the correlations to be operated at the SAW sensors, instead of the reader. Thus, the response signals arriving at the reader are the result of cross-correlation on the chips. It is then easy for the reader to distinguish the sensor that is matched with the interrogating signal. The operation principle, signal analysis, and simulation of the novel scheme are described in the paper. The simulation results show the response signals from the correlations of the sensors. A clear spike pulse is presented in the response signals, when a sensor code is matched with the interrogating code. Simulations verify the feasibility of the on-chip correlator concept.

  8. Lab-on-chip systems for integrated bioanalyses.

    Science.gov (United States)

    Conde, João Pedro; Madaboosi, Narayanan; Soares, Ruben R G; Fernandes, João Tiago S; Novo, Pedro; Moulas, Geraud; Chu, Virginia

    2016-06-30

    Biomolecular detection systems based on microfluidics are often called lab-on-chip systems. To fully benefit from the miniaturization resulting from microfluidics, one aims to develop 'from sample-to-answer' analytical systems, in which the input is a raw or minimally processed biological, food/feed or environmental sample and the output is a quantitative or qualitative assessment of one or more analytes of interest. In general, such systems will require the integration of several steps or operations to perform their function. This review will discuss these stages of operation, including fluidic handling, which assures that the desired fluid arrives at a specific location at the right time and under the appropriate flow conditions; molecular recognition, which allows the capture of specific analytes at precise locations on the chip; transduction of the molecular recognition event into a measurable signal; sample preparation upstream from analyte capture; and signal amplification procedures to increase sensitivity. Seamless integration of the different stages is required to achieve a point-of-care/point-of-use lab-on-chip device that allows analyte detection at the relevant sensitivity ranges, with a competitive analysis time and cost.

  9. A Survey of Network-On-Chip Tools

    Directory of Open Access Journals (Sweden)

    Ahmed Ben Achballah

    2013-10-01

    Full Text Available Nowadays System-On-Chips (SoCs have evolved considerably in term of performances, reliability and integration capacity. The last advantage has induced the growth of the number of cores or Intellectual Properties (IPs in a same chip. Unfortunately, this important number of IPs has caused a new issue which is the intra-communication between the elements of a same chip. To resolve this problem, a new paradigm has been introduced which is the Network-On-Chip (NoC. Since the introduction of the NoC paradigm in the last decade, new methodologies and approaches have been presented by research community and many of them have been adopted by industrials. The literature contains many relevant studies and surveys discussing NoC proposals and contributions. However, few of them have discussed or proposed a comparative study of NoC tools. The objective of this work is to establish a reliable survey about available design, simulation or implementation NoC tools. We collected an important amount of information and characteristics about NoC dedicated tools that we will present throughout this survey. This study is built around a respectable amount of references and we hope it will help scientists.

  10. A Miniaturized On-Chip Colorimeter for Detecting NPK Elements

    Science.gov (United States)

    Liu, Rui-Tao; Tao, Lu-Qi; Liu, Bo; Tian, Xiang-Guang; Mohammad, Mohammad Ali; Yang, Yi; Ren, Tian-Ling

    2016-01-01

    Recently, precision agriculture has become a globally attractive topic. As one of the most important factors, the soil nutrients play an important role in estimating the development of precision agriculture. Detecting the content of nitrogen, phosphorus and potassium (NPK) elements more efficiently is one of the key issues. In this paper, a novel chip-level colorimeter was fabricated to detect the NPK elements for the first time. A light source–microchannel photodetector in a sandwich structure was designed to realize on-chip detection. Compared with a commercial colorimeter, all key parts are based on MEMS (Micro-Electro-Mechanical System) technology so that the volume of this on-chip colorimeter can be minimized. Besides, less error and high precision are achieved. The cost of this colorimeter is two orders of magnitude less than that of a commercial one. All these advantages enable a low-cost and high-precision sensing operation in a monitoring network. The colorimeter developed herein has bright prospects for environmental and biological applications. PMID:27527177

  11. Lab-on-chip systems for integrated bioanalyses

    Science.gov (United States)

    Madaboosi, Narayanan; Soares, Ruben R.G.; Fernandes, João Tiago S.; Novo, Pedro; Moulas, Geraud; Chu, Virginia

    2016-01-01

    Biomolecular detection systems based on microfluidics are often called lab-on-chip systems. To fully benefit from the miniaturization resulting from microfluidics, one aims to develop ‘from sample-to-answer’ analytical systems, in which the input is a raw or minimally processed biological, food/feed or environmental sample and the output is a quantitative or qualitative assessment of one or more analytes of interest. In general, such systems will require the integration of several steps or operations to perform their function. This review will discuss these stages of operation, including fluidic handling, which assures that the desired fluid arrives at a specific location at the right time and under the appropriate flow conditions; molecular recognition, which allows the capture of specific analytes at precise locations on the chip; transduction of the molecular recognition event into a measurable signal; sample preparation upstream from analyte capture; and signal amplification procedures to increase sensitivity. Seamless integration of the different stages is required to achieve a point-of-care/point-of-use lab-on-chip device that allows analyte detection at the relevant sensitivity ranges, with a competitive analysis time and cost. PMID:27365042

  12. Self-powered integrated systems-on-chip (energy chip)

    KAUST Repository

    Hussain, Muhammad Mustafa

    2010-04-23

    In today\\'s world, consumer driven technology wants more portable electronic gadgets to be developed, and the next big thing in line is self-powered handheld devices. Therefore to reduce the power consumption as well as to supply sufficient power to run those devices, several critical technical challenges need to be overcome: a. Nanofabrication of macro/micro systems which incorporates the direct benefit of light weight (thus portability), low power consumption, faster response, higher sensitivity and batch production (low cost). b. Integration of advanced nano-materials to meet the performance/cost benefit trend. Nano-materials may offer new functionalities that were previously underutilized in the macro/micro dimension. c. Energy efficiency to reduce power consumption and to supply enough power to meet that low power demand. We present a pragmatic perspective on a self-powered integrated System on Chip (SoC). We envision the integrated device will have two objectives: low power consumption/dissipation and on-chip power generation for implementation into handheld or remote technologies for defense, space, harsh environments and medical applications. This paper provides insight on materials choices, intelligent circuit design, and CMOS compatible integration.

  13. On-chip magnetic cooling of a nanoelectronic device

    Science.gov (United States)

    Bradley, D. I.; Guénault, A. M.; Gunnarsson, D.; Haley, R. P.; Holt, S.; Jones, A. T.; Pashkin, Yu. A.; Penttilä, J.; Prance, J. R.; Prunnila, M.; Roschier, L.

    2017-04-01

    We demonstrate significant cooling of electrons in a nanostructure below 10 mK by demagnetisation of thin-film copper on a silicon chip. Our approach overcomes the typical bottleneck of weak electron-phonon scattering by coupling the electrons directly to a bath of refrigerated nuclei, rather than cooling via phonons in the host lattice. Consequently, weak electron-phonon scattering becomes an advant- age. It allows the electrons to be cooled for an experimentally useful period of time to temperatures colder than the dilution refrigerator platform, the incoming electrical connections, and the host lattice. There are efforts worldwide to reach sub-millikelvin electron temperatures in nanostructures to study coherent electronic phenomena and improve the operation of nanoelectronic devices. On-chip magnetic cooling is a promising approach to meet this challenge. The method can be used to reach low, local electron temperatures in other nanostructures, obviating the need to adapt traditional, large demagnetisation stages. We demonstrate the technique by applying it to a nanoelectronic primary thermometer that measures its internal electron temperature. Using an optimised demagnetisation process, we demonstrate cooling of the on-chip electrons from 9 mK to below 5 mK for over 1000 seconds.

  14. Bio-Inspired Controller on an FPGA Applied to Closed-Loop Diaphragmatic Stimulation.

    Science.gov (United States)

    Zbrzeski, Adeline; Bornat, Yannick; Hillen, Brian; Siu, Ricardo; Abbas, James; Jung, Ranu; Renaud, Sylvie

    2016-01-01

    Cervical spinal cord injury can disrupt connections between the brain respiratory network and the respiratory muscles which can lead to partial or complete loss of ventilatory control and require ventilatory assistance. Unlike current open-loop technology, a closed-loop diaphragmatic pacing system could overcome the drawbacks of manual titration as well as respond to changing ventilation requirements. We present an original bio-inspired assistive technology for real-time ventilation assistance, implemented in a digital configurable Field Programmable Gate Array (FPGA). The bio-inspired controller, which is a spiking neural network (SNN) inspired by the medullary respiratory network, is as robust as a classic controller while having a flexible, low-power and low-cost hardware design. The system was simulated in MATLAB with FPGA-specific constraints and tested with a computational model of rat breathing; the model reproduced experimentally collected respiratory data in eupneic animals. The open-loop version of the bio-inspired controller was implemented on the FPGA. Electrical test bench characterizations confirmed the system functionality. Open and closed-loop paradigm simulations were simulated to test the FPGA system real-time behavior using the rat computational model. The closed-loop system monitors breathing and changes in respiratory demands to drive diaphragmatic stimulation. The simulated results inform future acute animal experiments and constitute the first step toward the development of a neuromorphic, adaptive, compact, low-power, implantable device. The bio-inspired hardware design optimizes the FPGA resource and time costs while harnessing the computational power of spike-based neuromorphic hardware. Its real-time feature makes it suitable for in vivo applications.

  15. A functional on-chip pressure generator using solid chemical propellant for disposable lab-on-a-chip.

    Science.gov (United States)

    Hong, Chien-Chong; Murugesan, Suresh; Kim, Sanghyo; Beaucage, Gregory; Choi, Jin-Woo; Ahn, Chong H

    2003-11-01

    This paper presents a functional on-chip pressure generator that utilizes chemical energy from a solid chemical propellant to perform fluidic delivery in applications of plastic-based disposable biochips or lab-on-a-chip systems. In this functional on-chip pressure generator, azobis-isobutyronitrile (AIBN) as the solid chemical propellant is deposited on a microheater using a screen-printing technique, which can heat the AIBN at 70 degrees C to produce nitrogen gas. The output pressure of nitrogen gas, generated from the solid chemical propellant, is adjustable to a desired pressure by controlling the input power of the heater. Using this chemical energy source, the generated pressure depends on the deposited amount of the solid chemical propellant and the temperature of the microheater. Experimental measurements show that this functional on-chip pressure generator can achieve around 3 000 Pa pressure when 189 mJ of energy is applied to heat the 100 microg of AIBN. This pressure can drive 50 nl of water through a microfluidic channel of 70 mm and cross-sectional area of 100 microm x 50 microm. Due to its compact size, ease of fabrication and integration, high reliability (no moving parts), biologically inert gas output along with functionality of gas generation, this pressure generator will be an excellent pressure source for handling the fluids of disposable lab-on-a-chip, biochemical analysis systems or drug delivery systems.

  16. Novel Walking Stability-Based Gait Recognition Method for Functional Electrical Stimulation System Control

    Institute of Scientific and Technical Information of China (English)

    MING Dong; WAN Baikun; HU Yong; WANG Yan; WANG Weijie; WU Yinghua; LU Dieji

    2007-01-01

    Gait recognition is the key question of functional electrical stimulation (FES) system control for paraplegic walking. A new risk-tendency-graph (RTG) method was proposed to recognize the stability information in FES-assisted walking gait. The main instrument was a specialized walker dynamometer system based on a multi-channel strain-gauge bridge network fixed on the walker frame. During walking process, this system collected the reaction forces between patient's upper extremities and walker and converted them into RTG morphologic curves of dynamic gait stability in temporal and spatial domains.To demonstrate the potential usefulness of RTG, preliminary clinical trials were done with paraplegic patients. The gait stability levels of two walking cases with 4- and 12-week FES training from one subject were quantified (0.43 and 0.19) from the results of temporal and spatial RTG. Relevant instable phases in gait cycle and dangerous inclinations of patient's body during walking process were also brought forward. In conclusion, the new RTG method is practical for distinguishing more useful gait stability information for FES system control.

  17. EEG controlled neuromuscular electrical stimulation of the upper limb for stroke patients

    Science.gov (United States)

    Tan, Hock Guan; Shee, Cheng Yap; Kong, Keng He; Guan, Cuntai; Ang, Wei Tech

    2011-03-01

    This paper describes the Brain Computer Interface (BCI) system and the experiments to allow post-acute (neuromuscular electrical stimulation (NMES)-assisted extension of the wrist/fingers, which are essential pre-requisites for useful hand function. EEG was recorded while subjects performed motor imagery of their paretic limb, and then analyzed to determine the optimal frequency range within the mu-rhythm, with the greatest attenuation. Aided by visual feedback, subjects then trained to regulate their mu-rhythm EEG to operate the BCI to trigger NMES of the wrist/finger. 6 post-acute stroke patients successfully completed the training, with 4 able to learn to control and use the BCI to initiate NMES. This result is consistent with the reported BCI literacy rate of healthy subjects. Thereafter, without the loss of generality, the controller of the NMES is developed and is based on a model of the upper limb muscle (biceps/triceps) groups to determine the intensity of NMES required to flex or extend the forearm by a specific angle. The muscle model is based on a phenomenological approach, with parameters that are easily measured and conveniently implemented.

  18. Adaptive control of functional neuromuscular stimulation-induced knee extension exercise.

    Science.gov (United States)

    Ezenwa, B N; Glaser, R M; Couch, W; Figoni, S F; Rodgers, M M

    1991-01-01

    An automated system for exercising the paralyzed quadriceps muscles of spinal cord injured patients using functional neuromuscular stimulation (FNS) has been developed. It induces smooth concentric and eccentric contractions in both limbs to enable bilateral 70 degree knee extensions in an asynchronous pattern. External load resistance is applied at the ankle level to "overload" the muscles and bring about training effects. The system uses adaptive control methods to adjust FNS current output (threshold level and the ramp slope) to the quadriceps muscles to maintain performance as the muscles fatigue. Feedback control signals for limb movement and knee extension angle are used to continuously adjust the FNS current parameters so that the external load is moved through the preset zero to 70 degree angle range. Typically, the threshold current level and the FNS current increase as the muscles fatigue to maintain performance with repetitive contractions. Fatigue is defined as the inability to extend the knee to 50 percent of the 70 degree target angle. When this occurs, FNS is automatically terminated for the fatigued leg, while the functioning leg continues to exercise. The automated nature of this system appears to be advantageous as compared to a manually operated system for subject safety, convenience, and uniformity of exercise bouts. Simulated safety problems, such as hyperextension of the knee joint, open circuitry, muscle spasms, and low battery power, were successfully detected by the logic circuitry, and the system followed appropriate safety procedures to minimize risk.

  19. A Randomized Controlled Trial of Auricular Transcutaneous Electrical Nerve Stimulation for Managing Posthysterectomy Pain

    Directory of Open Access Journals (Sweden)

    Hin Cheung Tsang

    2011-01-01

    Result. As compared to the baseline, only the true TENS group reported a significant reduction in VAS-rest (P=.001, VAS-huff (P=.004, and VAS-cough (P=.001, while no significant reduction in any of the VAS scores was seen in the sham TENS group (all P>.05. In contrast, a small rising trend was observed in the VAS-rest and VAS-huff scores of the control group, while the VAS-cough score remained largely unchanged during the period of the study. A between-group comparison revealed that all three VAS scores of the true TENS group were significantly lower than those of the control group at 15 and 30 minutes after the intervention (all P<.02. No significant between-group difference was observed in PEFR at any point in time. Conclusion. A single session of auricular TENS applied at specific therapeutic points significantly reduced resting (VAS-rest and movement-evoked pain (VAS-huff, VAS-cough, and the effects lasted for at least 30 minutes after the stimulation. The analgesic effects of auricular TENS appeared to be point specific and could not be attributed to the placebo effect alone. However, auricular TENS did not produce any significant improvement in the performance of PEFR.

  20. Helping people in a minimally conscious state develop responding and stimulation control through a microswitch-aided program.

    Science.gov (United States)

    Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Sigafoos, Jeff; D'Amico, Fiora; Buonocunto, Francesca; Navarro, Jorge; Lanzilotti, Crocifissa; Fiore, Pietro; Megna, Marisa; Damiani, Sabino; Marvulli, Riccardo

    2017-06-01

    Postcoma persons in a minimally conscious state (MCS) and with extensive motor impairment cannot independently access and control environmental stimulation. Assessing the effects of a microswitch-aided program aimed at helping MCS persons develop responding and stimulation control and conducting a social validation/evaluation of the program. A single-subject ABAB design was used for each participant to determine the impact of the program on his or her responding. Staff interviews were used for the social validation/evaluation of the program. Rehabilitation and care facilities that the participants attended. Eleven MCS persons with extensive motor impairment and lack of speech or any other functional communication. For each participant, baseline (A) phases were alternated with intervention (B) phases during which the program was used. The program relied on microswitches to monitor participants' specific responses (e.g., prolonged eyelid closures) and on a computer system to enable those responses to control stimulation. In practice, the participants could use a simple response such as prolonged eyelid closure to generate a new stimulation input. Sixty-six staff people took part in the social validation of the program. They were to compare the program to basic and elaborate forms of externally controlled stimulation, scoring each of them on a six-item questionnaire. All participants showed increased response frequencies (and thus higher levels of independent stimulation input/control) during the B phases of the study. Their frequencies for each intervention phase more than doubled their frequencies for the preceding baseline phase with the difference between the two being clearly significant (Pprogram on five of the six questionnaire items. A microswitch-aided program can be an effective and socially acceptable tool in the work with MCS persons. The participants and staff's data can be taken as an encouragement for the use of a microswitch-aided program within care

  1. Stimulation of NTS A1 adenosine receptors differentially resets baroreflex control of regional sympathetic outputs.

    Science.gov (United States)

    Scislo, Tadeusz J; Ichinose, Tomoko K; O'Leary, Donal S

    2008-01-01

    Previously we showed that pressor and differential regional sympathoexcitatory responses (adrenal > renal >/= lumbar) evoked by stimulation of A(1) adenosine receptors located in the nucleus of the solitary tract (NTS) were attenuated/abolished by baroreceptor denervation or blockade of glutamatergic transmission in the NTS, suggesting A(1) receptor-elicited inhibition of glutamatergic transmission in baroreflex pathways. Therefore we tested the hypothesis that stimulation of NTS A(1) adenosine receptors differentially inhibits/resets baroreflex responses of preganglionic adrenal (pre-ASNA), renal (RSNA), and lumbar (LSNA) sympathetic nerve activity. In urethane-chloralose-anesthetized male Sprague-Dawley rats (n = 65) we compared baroreflex-response curves (iv nitroprusside and phenylephrine) evoked before and after bilateral microinjections into the NTS of A(1) adenosine receptor agonist (N(6)-cyclopentyladenosine, CPA; 0.033-330 pmol/50 nl). CPA evoked typical dose-dependent pressor and differential sympathoexcitatory responses and similarly shifted baroreflex curves for pre-ASNA, RSNA, and LSNA toward higher mean arterial pressure (MAP) in a dose-dependent manner; the maximal shifts were 52.6 +/- 2.8, 48.0 +/- 3.6, and 56.8 +/- 6.7 mmHg for pre-ASNA, RSNA, and LSNA, respectively. These shifts were not a result of simple baroreceptor resetting because they were two to three times greater than respective increases in baseline MAP evoked by CPA. Baroreflex curves for pre-ASNA were additionally shifted upward: the maximal increases of upper and lower plateaus were 41.8 +/- 16.4% and 45.3 +/- 8.7%, respectively. Maximal gain (%/mmHg) measured before vs. after CPA increased for pre-ASNA (3.0 +/- 0.6 vs. 4.9 +/- 1.3), decreased for RSNA (4.1 +/- 0.6 vs. 2.3 +/- 0.3), and remained unaltered for LSNA (2.1 +/- 0.2 vs. 2.0 +/- 0.1). Vehicle control did not alter the baroreflex curves. We conclude that the activation of NTS A(1) adenosine receptors differentially inhibits

  2. Dense cranial electroacupuncture stimulation for major depressive disorder--a single-blind, randomized, controlled study.

    Directory of Open Access Journals (Sweden)

    Zhang-Jin Zhang

    Full Text Available BACKGROUND: Previous studies suggest that electroacupuncture possesses therapeutic benefits for depressive disorders. The purpose of this study was to determine whether dense cranial electroacupuncture stimulation (DCEAS could enhance the antidepressant efficacy in the early phase of selective serotonin reuptake inhibitor (SSRI treatment of major depressive disorder (MDD. METHODS: In this single-blind, randomized, controlled study, patients with MDD were randomly assigned to 9-session DCEAS or noninvasive electroacupuncture (n-EA control procedure in combination with fluoxetine (FLX for 3 weeks. Clinical outcomes were measured using the 17-item Hamilton Depression Rating Scale (HAMD-17, Clinical Global Impression-severity (CGI-S, and Self-rating Depression Scale (SDS as well as the response and remission rates. RESULTS: Seventy-three patients were randomly assigned to n-EA (n = 35 and DCEAS (n = 38, of whom 34 in n-EA and 36 in DCEAS group were analyzed. DCEAS-treated patients displayed a significantly greater reduction from baseline in HAMD-17 scores at Day 3 through Day 21 and in SDS scores at Day 3 and Day 21 compared to patients receiving n-EA. DCEAS intervention also produced a higher rate of clinically significant response compared to n-EA procedure (19.4% (7/36 vs. 8.8% (3/34. The incidence of adverse events was similar in the two groups. CONCLUSIONS: DCEAS is a safe and effective intervention that augments the antidepressant efficacy. It can be considered as an additional therapy in the early phase of SSRI treatment of depressed patients. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN88008690.

  3. Transcranial direct current stimulation versus user training on improving online myoelectric control for amputees

    Science.gov (United States)

    Pan, Lizhi; Zhang, Dingguo; Jiang, Ning; Sheng, Xinjun; Zhu, Xiangyang

    2017-08-01

    Objective. Transcranial direct current stimulation (tDCS) and user training (UT) are two types of methods to improve myoelectric control performance for amputees. In this study, we compared the independent effect between tDCS and UT, and investigated the combined effect of tDCS and UT. Approach. An online paradigm of simultaneous and proportional control (SPC) based on electromyography (EMG) was adopted. The proposed experiments were conducted on six naïve unilateral trans-radial amputees. The subjects each received three types of 20 min interventions: active tDCS with motor training (tDCS  +  UT), active tDCS with quiet sitting (tDCS), and sham tDCS with motor training (UT). The interventions were applied at one week intervals in a randomized order. The subjects performed online control of a feedback arrow with two degrees of freedom (DoFs) to accomplish target reaching motor tasks in pre-sessions and post-sessions. We compared the performance, measured by completion rate, completion time, and efficiency coefficient, between pre-sessions and post-sessions. Main results. The results showed that the intervention tDCS  +  UT and tDCS significantly improved the online SPC performance (i.e. improved the completion rate; reduced the completion time; and improved the efficiency coefficient), while intervention UT did not significantly change the performance. The results also showed that the online SPC performance after intervention tDCS  +  UT and tDCS was not significantly different, but both were significantly better than that after intervention UT. Significance. tDCS could be an effective intervention to improve the online SPC performance in a short time.

  4. A Three-Dimensional Object Orientation Detector Assisting People with Developmental Disabilities to Control Their Environmental Stimulation through Simple Occupational Activities with a Nintendo Wii Remote Controller

    Science.gov (United States)

    Shih, Ching-Hsiang; Chang, Man-Ling; Mohua, Zhang

    2012-01-01

    This study evaluated whether two people with developmental disabilities would be able to actively perform simple occupational activities to control their preferred environmental stimulation using a Nintendo Wii Remote Controller with a newly developed three-dimensional object orientation detection program (TDOODP, i.e. a new software program,…

  5. Random-start controlled ovarian stimulation for emergency fertility preservation in a patient with myelodysplastic syndrome: a case report

    Directory of Open Access Journals (Sweden)

    H. Cai

    2016-01-01

    Full Text Available This study reports a case of a gonadotropin-releasing hormone agonist trigger in a young female with myelodysplastic syndrome (MDS who underwent fertility preservation using random-start controlled ovarian stimulation. This method involves the stimulation of the ovary regardless of a patient's menstrual-cycle phase. A review of the related literature is also provided. A 17-year-old patient was diagnosed with MDS and required initiation of peripheral blood stem cell transplantation within a maximum of 3 weeks and was in the luteal phase of the menstrual cycle when the possibility of attempting preservation of fertility was presented to her. She opted for a random-start controlled ovarian stimulation with gonadotropins. With successful hemorrhagic prophylaxis, 17 oocytes were retrieved including 10 mature and 7 immature oocytes. Of the immature oocytes, 3 were successfully matured in vitro and a vitrification protocol was used to freeze the 13 mature oocytes.

  6. Efficacy of Electrical Stimulators for Bone Healing: A Meta-Analysis of Randomized Sham-Controlled Trials.

    Science.gov (United States)

    Aleem, Ilyas S; Aleem, Idris; Evaniew, Nathan; Busse, Jason W; Yaszemski, Michael; Agarwal, Arnav; Einhorn, Thomas; Bhandari, Mohit

    2016-08-19

    Electrical stimulation is a common adjunct used to promote bone healing; its efficacy, however, remains uncertain. We conducted a meta-analysis of randomized sham-controlled trials to establish the efficacy of electrical stimulation for bone healing. We identified all trials randomizing patients to electrical or sham stimulation for bone healing. Outcomes were pain relief, functional improvement, and radiographic nonunion. Two reviewers assessed eligibility and risk of bias, performed data extraction, and rated the quality of the evidence. Fifteen trials met our inclusion criteria. Moderate quality evidence from 4 trials found that stimulation produced a significant improvement in pain (mean difference (MD) on 100-millimeter visual analogue scale = -7.7 mm; 95% CI -13.92 to -1.43; p = 0.02). Two trials found no difference in functional outcome (MD = -0.88; 95% CI -6.63 to 4.87; p = 0.76). Moderate quality evidence from 15 trials found that stimulation reduced radiographic nonunion rates by 35% (95% CI 19% to 47%; number needed to treat = 7; p < 0.01). Patients treated with electrical stimulation as an adjunct for bone healing have less pain and are at reduced risk for radiographic nonunion; functional outcome data are limited and requires increased focus in future trials.

  7. Paraplegic standing controlled by functional neuromuscular stimulation: Part I--computer model and control-system design.

    Science.gov (United States)

    Khang, G; Zajac, F E

    1989-09-01

    We have developed a planar computer model to investigate paraplegic standing induced by functional neuromuscular stimulation. The model consists of nonlinear musculotendon dynamics (pulse train activation dynamics and musculotendon actuator dynamics), nonlinear body-segmental dynamics, and a linear output-feedback control law. The model of activation dynamics is an analytic expression that characterizes the relation between the stimulus parameters (pulse width and interpulse interval) and the muscle activation. Hill's classic two-element muscle model was modified into a musculotendon actuator model in order to account for the effects of submaximal activation and tendon elasticity on development of force by the actuator. The three body-segmental, multijoint model accounts for the anterior-posterior movements of the head and trunk, the thigh, and the shank. We modeled arm movement as an external disturbance and imposed the disturbance to the body-segmental dynamics by means of a quasistatic analysis. Linearization, and at times linear approximation of the computer model, enabled us to compute a constant, linear feedback-gain matrix, whose output is the net activation needed by a dynamical joint-torque actuator. Motivated by an assumption that minimization of energy expenditure lessens muscle fatigue, we developed an algorithm that then computes how to distribute the net activation among all the muscles crossing the joint. In part II, the combined feedback control strategy is applied to the nonlinear model of musculotendon and body-segmental dynamics to study how well the body ought to maintain balance should the feedback control strategy be employed.

  8. Cycle-to-cycle control of swing phase of paraplegic gait induced by surface electrical stimulation

    NARCIS (Netherlands)

    Franken, H.M.; Veltink, P.H.; Baardman, G.; Redmeijer, R.A.

    1995-01-01

    Parameterised swing phase of gait in paraplegics was obtained using surface electrical stimulation of the hip flexors, hamstrings and quadriceps; the hip flexors were stimulated to obtain a desired hip angle range, the hamstrings to provide foot clearance in the forward swing, and the quadriceps to

  9. Controlled Vestibular Stimulation, Standardization Of A Physiological Method To Release Stress In College Students.

    Science.gov (United States)

    Sailesh, Kumar Sai; Mukkadan, J K

    2015-01-01

    The present study was designed to standardize optimal vestibular stimulation and to investigate its impact on anxiety levels in college students. Vestibular stimulation was achieved by swinging on a swing (Back to front direction) and the participants were advised to adjust frequency, duration and intensity, according to comfort. Frequency, intensity and duration were recorded manually. The anxiety status was assessed by using Spielberger state-trait anxiety inventory (STAI) before and after vestibular stimulation. It has been observed that the anxiety status was significantly decreased after vestibular stimulation. There is a need for future study with larger sample size to substantiate the therapeutic validity of vestibular stimulation as a physiological treatment for stress relief and stress related disorders among college students.

  10. Mass parasite control as an approach to stimulate community acceptance of environmental sanitation.

    Science.gov (United States)

    Trainer, E S

    1983-01-01

    Asian experiences show that programs for the control of intestinal parasites have been able to stimulate village level interest in environmental sanitation as evidenced by increased demand for latrines. Mass parasite control can have a positive impact on the sociocultural and program design constraints of traditional sanitation projects. In the Integrated Family Planning and Parasite Control Project, the psychological impact on treated individuals, plus the improved sense of well-being and strengthened interest in health care which often follow, had 2 results. First, the feeling of appreciation and trust by the people towards the workers who provide the medicine, thus enhancing worker credibility. Secondly, if the deworming is carried out on a communitywide basis accompanied by concrete health education on parasite life cycles, the individual impact will be broadened and strengthened to the point where the people, or at least their leaders, will want to get rid of the worms in their environment. This requires organized and sustained community action for parasite control, environmental sanitation and family hygiene. Basic operating principles consist of 3 elements: the institutional framework; community involvement; and recruitment and training of staff. It is best to begin a program on a pilot basis perhaps in rural localities of greatest concern to sanitarians. Success depends on whether a cooperative relationship has been established among steering committees and the people. Field workers promote and deliver services, link the village's interests with those of the project and its related programs, and provide technical and logistical support to the community effort to organize itself to implement and institutionalize these programs. Medical workers use the Kato Method and Kato Katz Method in determining parasitic infection. The Kato Method reveals only the presence or absence of worms, and is easy to do in a field situation; the Kato Katz Method can also measure

  11. Subthalamic Stimulation Reduces Vowel Space at the Initiation of Sustained Production: Implications for Articulatory Motor Control in Parkinson's Disease.

    Science.gov (United States)

    Sidtis, John J; Alken, Amy G; Tagliati, Michele; Alterman, Ron; Van Lancker Sidtis, Diana

    2016-03-19

    Stimulation of the subthalamic nuclei (STN) is an effective treatment for Parkinson's disease, but complaints of speech difficulties after surgery have been difficult to quantify. Speech measures do not convincingly account for such reports. This study examined STN stimulation effects on vowel production, in order to probe whether DBS affects articulatory posturing. The objective was to compare positioning during the initiation phase with the steady prolongation phase by measuring vowel spaces for three "corner" vowels at these two time frames. Vowel space was measured over the initial 0.25 sec of sustained productions of high front (/i/), high back (/u/) and low vowels (/a/), and again during a 2 sec segment at the midpoint. Eight right-handed male subjects with bilateral STN stimulation and seven age-matched male controls were studied based on their participation in a larger study that included functional imaging. Mean values: age = 57±4.6 yrs; PD duration = 12.3±2.7 yrs; duration of DBS = 25.6±21.2 mos, and UPDRS III speech score = 1.6±0.7. STN subjects were studied off medication at their therapeutic DBS settings and again with their stimulators off, counter-balanced order. Vowel space was larger in the initiation phase compared to the midpoint for both the control and the STN subjects off stimulation. With stimulation on, however, the initial vowel space was significantly reduced to the area measured at the mid-point. For the three vowels, the acoustics were differentially affected, in accordance with expected effects of front versus back position in the vocal tract. STN stimulation appears to constrain initial articulatory gestures for vowel production, raising the possibility that articulatory positions normally used in speech are similarly constrained.

  12. The effect of Functional Electric Stimulation in stroke patients' motor control - a case report

    Science.gov (United States)

    Pripas, Denise; Rogers Venditi Beas, Allan; Fioramonte, Caroline; Gonsales de Castro, Pedro Claudio; Goroso, Daniel Gustavo; Cecília dos Santos Moreira, Maria

    2011-12-01

    Functional Electric Stimulation (FES) has been studied as a therapeutic resource to reduce spasticity in hemiplegic patients, however there are no studies about the effects of FES in motor control of these patients during functional tasks like balance maintenance. Muscular activation of gastrocnemius medialis and semitendinosus was investigated in both limbs of a hemiparetic patient during self-disturbed quiet stance before and after FES on tibialis anterior, by surface electromyography. The instant of maximum activation peak of GM and ST were calculated immediately after a motor self-disturbance, in order to observe muscular synergy between these two muscles, and possible balance strategies used (ankle or hip strategy). At the preserved limb there occurred distal-proximal synergy (GM followed by ST), expected for small perturbations; however, at spastic limb there was inversion of this synergy (proximal-distal) after FES. It is possible that intervention of electricity had inhibited synergical pathways due to antidromic effect, making it difficult to use ankle strategy in the spastic limb.

  13. Genetic control of macrophage functions. I. Polygenic regulation of phagocytosis stimulation produced by Glyceryl Trioleate.

    Science.gov (United States)

    Mouton, D; Bouthillier, Y; Feingold, N; Feingold, J; Decreusefond, C; Stiffel, C; Biozzi, G

    1975-02-01

    The phagocytic index K, established from the rate of blood clearance of colloidal carbon, measures the phagocytic activity of RE macrophages in contact with the circulating blood. The intravenous injection of glyceryl trioleate (triolein) produces a marked stimulation of the phagocytic activity of RE macrophages. This response is higher in the female than in the male mice. The phenotypic character "responsiveness of macrophage to triolein" presents large individual variants in population of random bred albinos mice. This character is submitted to polygenic regulation. Starting from a foundation population of 25 males and 25 females random bred albinos, mice, two lines were separated by selective breeding for the character "responsiveness to triolein": a "high" responder line, KTH, and a "low" responder line, KTL. After 26 consecutive generations of selective breeding, KTH mice present a very high response to triolein while KTL mice are almost irresponsive. The heritability of this character (h2) calculated from the interline divergence is of 12% plus or minus 1. This value of h2 indicates that the character investigated is determined by the cumulative effect of a group of about 27 independently segregating loci. The distribution of the character in (KTH plus KTL)F1 and their backcrosses with parental lines suggests that low responsiveness is dominant over high responsiveness. The genetic regulation of responsiveness to triolein is independent from the dose administered. These results are discussed in relation to the importance of genetic factors controlling macrophage functions involved in lipid metabolism and in the specific mechanisms of immunity.

  14. Percutaneous tibial nerve stimulation versus tolterodine for overactive bladder in women: a randomised controlled trial.

    Science.gov (United States)

    Preyer, Oliver; Umek, Wolfgang; Laml, Thomas; Bjelic-Radisic, Vesna; Gabriel, Boris; Mittlboeck, Martina; Hanzal, Engelbert

    2015-08-01

    We performed a randomised controlled trial of percutaneous tibial nerve stimulation (PTNS) versus tolterodine for treating treatment naïve women with overactive bladder (OAB). 36 patients with symptoms of OAB were randomised to 3 months of treatment with weekly PTNS or tolterodine (2mg bid p.o.). The primary outcome measure was the difference of micturitions per 24h. The secondary outcome measure was the impact on quality of life (QoL) measured with a visual analogue scale (VAS) between baseline and after 3 months of therapy. Micturition frequencies did not decline significantly (p=0.13) over time and there were no significant treatment differences (p=0.96). QoL was significantly dependent from its level at baseline (p=0.002) and showed improvement over time compared to baseline measurements but no significant differences between both treatment groups (p=0.07). Incontinence episodes per 24h depended significantly on the level at baseline (p=0.0001) and declined significantly (p=0.03) during 3 months of therapy in both therapy groups. However no significant treatment differences on the reduction of incontinence episodes in 24h could be shown between both therapy groups (p=0.89). PTNS had fewer side effects than tolterodine (p=0.04). PTNS and tolterodine were both effective in reducing incontinence episodes and improving QoL in patients with OAB but not micturition frequencies. PTNS had fewer side effects. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. A low overhead load balancing router for network-on-chip

    Science.gov (United States)

    Xiaofeng, Zhou; Lu, Liu; Zhangming, Zhu; Duan, Zhou

    2016-11-01

    The design of a router in a network-on-chip (NoC) system has an important impact on some performance criteria. In this paper, we propose a low overhead load balancing router (LOLBR) for 2D mesh NoC to enhance routing performance criteria with low hardware overhead. The proposed LOLBR employs a balance toggle identifier to control the initial routing direction of X or Y for flit injection. The simplified demultiplexers and multiplexers are used to handle output ports allocation and contention, which provide a guarantee of deadlock avoidance. Simulation results show that the proposed LOLBR yields an improvement of routing performance over the reported routing schemes in average packet latency by 26.5%. The layout area and power consumption of the network compared with the reported routing schemes are 15.3% and 11.6% less respectively. Project supported by the National Natural Science Foundation of China (Nos. 61474087, 61322405, 61376039).

  16. A multi-chip data acquisition system based on a heterogeneous system-on-chip platform

    CERN Document Server

    Fiergolski, Adrian

    2017-01-01

    The Control and Readout Inner tracking BOard (CaRIBOu) is a versatile readout system targeting a multitude of detector prototypes. It profits from the heterogeneous platform of the Zynq System-on-Chip (SoC) and integrates in a monolithic device front-end FPGA resources with a back-end software running on a hard-core ARM-based processor. The user-friendly Linux terminal with the pre-installed DAQ software is combined with the efficiency and throughput of a system fully implemented in the FPGA fabric. The paper presents the design of the SoC-based DAQ system and its building blocks. It also shows examples of the achieved functionality for the CLICpix2 readout ASIC.

  17. Validation study for using lab-on-chip technology for Coxiella burnetii multi-locus-VNTR-analysis (MLVA) typing: application for studying genotypic diversity of strains from domestic ruminants in France.

    Science.gov (United States)

    Prigent, Myriam; Rousset, Elodie; Yang, Elise; Thiéry, Richard; Sidi-Boumedine, Karim

    2015-01-01

    Coxiella burnetii, the etiologic bacterium of Q fever zoonosis, is still difficult to control. Ruminants are often carriers and involved in human epidemics. MLVA is a promising genotyping method for molecular epidemiology. Different techniques are used to resolve the MLVA band profiles such as electrophoresis on agarose gels, capillary electrophoresis or using the microfluidic Lab-on-Chip system. In this study, system based on microfluidics electrophoresis with Lab-on-Chip technology was assessed and applied on DNA field samples to investigate the genotypic diversity of C. burnetii strains circulating in France. The Lab-on-Chip technology was first compared to agarose gel electrophoresis. Subsequently, the set-up Lab-on-Chip technology was applied on 97 samples collected from ruminants in France using the 17 markers previously described. A discordance rate of 27% was observed between Lab-on-Chip and agarose gel electrophoresis. These discrepancies were checked and resolved by sequencing. The cluster analysis revealed classification based on host species and/or geographic origin criteria. Moreover, the circulation of different genotypic strains within the same farm was also observed. In this study, MLVA with Lab-on-Chip technology was shown to be more accurate, reproducible, user friendly and safer than gel electrophoresis. It also provides an extended data set from French ruminant C. burnetii circulating strains useful for epidemiological investigations. Finally, it raises some questions regarding the standardization and harmonization of C. burnetii MLVA genotyping.

  18. Therapeutic ultrasound to stimulate osteoconduction - A placebo controlled single blind study using e-PTFE membranes in rats

    NARCIS (Netherlands)

    Schortinghuis, J; Ruben, JL; Raghoebar, GM; Stegenga, B

    2004-01-01

    To decrease heating time of bone defects covered with osteoconductive membranes, an attempt was made to stimulate the osteoconductive process with therapeutic ultrasound. In 72 rats, a circular mandibular defect was created and covered on both sides with an e-PTFE membrane. A control group, an ultra

  19. Assisting People with Multiple Disabilities and Minimal Motor Behavior to Control Environmental Stimulation through a Mouse Wheel

    Science.gov (United States)

    Shih, Ching-Hsiang; Shih, Ching-Tien; Lin, Kun-Tsan; Chiang, Ming-Shan

    2009-01-01

    This study assessed whether two people with profound multiple disabilities and minimal motor behavior would be able to control environmental stimulation using thumb poke ability with a mouse wheel and a newly developed mouse driver (i.e., a new mouse driver replacing standard mouse driver, and turning a mouse into a precise thumb poke detector).…

  20. Center of mass acceleration feedback control of standing balance by functional neuromuscular stimulation against external postural perturbations.

    Science.gov (United States)

    Nataraj, Raviraj; Audu, Musa L; Triolo, Ronald J

    2013-01-01

    This study investigated the use of center of mass (COM) acceleration feedback for improving performance of a functional neuromuscular stimulation control system to restore standing function to a subject with complete, thoracic-level spinal cord injury. The approach for linearly relating changes in muscle stimulation to changes in COM acceleration was verified experimentally and subsequently produced data to create an input-output map driven by sensor feedback. The feedback gains were systematically tuned to reduce upper extremity (UE) loads applied to an instrumented support device while resisting external postural disturbances. Total body COM acceleration was accurately estimated (>89% variance explained) using 3-D outputs of two accelerometers mounted on the pelvis and torso. Compared to constant muscle stimulation employed clinically, feedback control of stimulation reduced UE loading by 33%. COM acceleration feedback is advantageous in constructing a standing neuroprosthesis since it provides the basis for a comprehensive control synergy about a global, dynamic variable and requires minimal instrumentation. Future work should include tuning and testing the feedback control system during functional reaching activity that is more indicative of activities of daily living.

  1. A randomized controlled trial of an implantable 2-channel peroneal nerve stimulator on walking speed and activity in poststroke hemiplegia

    NARCIS (Netherlands)

    Kottink, A.I.R.; Kottink, Anke I.; Hermens, Hermanus J.; Nene, A.V.; Tenniglo, Martinus Johannes Bernardus; van der Aa, Hans E.; Buschman, H.P.J.; IJzerman, Maarten Joost

    Objective To determine the effect of a new implantable 2-channel peroneal nerve stimulator on walking speed and daily activities, in comparison with the usual treatment in chronic stroke survivors with a drop foot. Design Randomized controlled trial. Setting All subjects were measured 5 times in the

  2. Milder ovarian stimulation for in-vitro fertilization reduces aneuploidy in the human preimplantation embryo : a randomized controlled trial

    NARCIS (Netherlands)

    Baart, Esther B.; Martini, Elena; Eijkemans, Marinus J.; Van Opstal, Diane; Beckers, Nicole G. M.; Verhoeff, Arie; Macklon, Nicolas S.; Fauser, Bart C. J. M.

    2007-01-01

    To test whether ovarian stimulation for in-vitro fertilization (IVF) affects oocyte quality and thus chromosome segregation behaviour during meiosis and early embryo development, preimplantation genetic screening of embryos was employed in a prospective, randomized controlled trial, comparing two ov

  3. Assisting People with Multiple Disabilities and Minimal Motor Behavior to Control Environmental Stimulation through a Mouse Wheel

    Science.gov (United States)

    Shih, Ching-Hsiang; Shih, Ching-Tien; Lin, Kun-Tsan; Chiang, Ming-Shan

    2009-01-01

    This study assessed whether two people with profound multiple disabilities and minimal motor behavior would be able to control environmental stimulation using thumb poke ability with a mouse wheel and a newly developed mouse driver (i.e., a new mouse driver replacing standard mouse driver, and turning a mouse into a precise thumb poke detector).…

  4. Avoiding Message-Dependent Deadlock in Network-Based Systems on Chip

    NARCIS (Netherlands)

    Hansson, A.; Goossens, K.; Rãdulescu, A.

    2007-01-01

    Networks on chip (NoCs) are an essential component of systems on chip (SoCs) and much research is devoted to deadlock avoidance in NoCs. Prior work focuses on the router network while protocol interactions between NoC and intellectual property (IP) modules are not considered. These interactions intr

  5. A run-time reconfigurable Network-on-Chip for streaming DSP applications

    NARCIS (Netherlands)

    Kavaldjiev, N.K.; Kavaldjiev, Nikolay Krasimirov

    2007-01-01

    With the advance of semiconductor technology, global on-chip wiring is becoming a limiting factor for the overall performance of large System-on-Chip (SoC) designs. In this thesis we propose a global communication architecture that avoids this limitation by structuring and shortening of the global

  6. On-Chip Hydrodynamic Chromatography Separation and Detection of Nanoparticles and Biomolecules

    NARCIS (Netherlands)

    Blom, M.T.; Chmela, Emil; Oosterbroek, R.E.; Tijssen, Robert; van den Berg, Albert

    2003-01-01

    For the first time, on-chip planar hydrodynamic chromatography is combined with UV absorption detection. This technique is suitable for size characterization of synthetic polymers, biopolymers, and particles. Possible advantages of an on-chip hydrodynamic chromatography system over conventional

  7. Studies on Renin Stimulation in Normal Controls and in Patients with Essential Hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Chang Soon; Choe, Kang Won; Lee, Hong Kyu; Lee, Jung Sang [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1978-03-15

    To find out a convenient and reliable method of detecting low renin status, we employed intravenous furosemide injection as a stimulatory maneuver. The results thus obtained were compared with those from the postural stimuli and basal plasma renin activity (PRA) in relation to sodium excretion. Intravenous furosemide test was performed in 66 control subjects and 44 patients with essential hypertension. The results were as follow; 1) Mean PRA in control subjects rose from 2.5+-1.95 ng/ml/hr (basal) to 4.5+-2.51, 5.2+-2.49 and 4.2+-2.44 ng/ml/hr at 1, 2 and 3 hrs after IV injection. One-hour response is more convenient in clinical practice. 2) Postural stimuli by assuming an upright posture for 3 hrs gave rise to considerable increase in PRA (4.0+-2.92 from 2.4+-1.85), but we found it less convenient than stimulation with furosemide. 3) The increase in PRA was much less marked in patients with essential hypertension as a whole (2.9+-2.75). Hyporesponsiveness to furosemide stimuli was found in 34.1%. Of these hyporesponders, a third had a normal basal PRA, indicating the need for this kind stimulatory procedure. 4) Younger age group showed greater renin responsiveness than older age group after furosemide stimuli. Likewise mean age of low renin patients (52.9+-5.38 years old) was significantly higher than that of high and normal renin patients (44.1+-13.78 years old).

  8. PERIPHERAL APPLICATION OF REPETITIVE PULSE MAGNETIC STIMULATION ON JOINT CONTRACTURE FOR MOBILITY RESTORATION: CONTROLLED RANDOMIZED STUDY

    Directory of Open Access Journals (Sweden)

    Efthimios J. Kouloulas

    2016-10-01

    Full Text Available Background: Joint contracture is a limitation in the passive or active range of motion (ROM of a joint, where in addition to the mobility limiting factor the pain is also present. Repetitive pulsed Magnetic Stimulation (rPMS appears to be an effective, non-invasive and safety solution for treating this condition. Therefore aim of this study was to evaluate the effect of rPMS in treating joint contracture. Methods: 30 subjects with joint contracture in the knee were enrolled in this study and divided respectively into Treatment and Control group. The treatment group were delivered with rPMS therapy. The control group was delivered with conventional physiotherapy method (ultrasound. The primary outcome measurements were: 1. Mobility evaluation by goniometry (ROM in degrees while performing flexion and Patient Functional Assessment Questionnaire (PFAQ for ability to perform Activities of Daily Living (ADL and 2. Pain evaluation by 10-point Visual Analog Scale (VAS for pain perception. Absence of adverse events was set as a secondary measure. Results: The results of the study show statistical difference (p<0.05 between the levels of improvement of all studied parameters while comparing between both groups. The results suggest greater immobility restoration and pain relieving effect of the rPMS in comparison to conventional physiotherapy method. Conclusion: rPMS an effective and safe non-invasive method for mobility restoration and pain relief in case of joint contractures. This study suggests the method as beneficial and quality of life ameliorating among patients suffering from immobilized joints accompanied by pain.

  9. Uniform droplet splitting and detection using Lab-on-Chip flow cytometry on a microfluidic PDMS device

    DEFF Research Database (Denmark)

    Kunstmann-Olsen, Casper; Hanczyc, Martin; Hoyland, James

    2016-01-01

    A PDMS chip is fabricated using soft lithography and applied to investigate the formation and division of nitrobenzene (NB) droplets in a two-phase system stabilized by oleic acid. Using an integrated on-chip flow cytometer setup, effected with optical fibers, droplet size distributions...... are analyzed in situ based on optical signal intensities. By controlling the hydrodynamic flow focusing, uniform droplets of sizes between 100 μm and 300 μm are created with precise size control. Cross-flow shearing allows one to divide these droplets into anything from 2 to 9 individual droplets, depending...

  10. Semiconductor plasmonic gas sensor using on-chip infrared spectroscopy

    Science.gov (United States)

    Elsayed, Mohamed Y.; Ismail, Yehea; Swillam, Mohamed A.

    2017-01-01

    In this paper, we take a novel approach in on-chip optical sensing of gases. Gases have conventionally been optically sensed using refractive index, which is a non-ideal method because of the difficulty in differentiating gases with very similar refractive indices. Infrared (IR) absorption spectra on the other hand have characteristic peaks in the fingerprint region that allow identifying the analyte. Highly doped n-type Indium Arsenide was used to design a plasmonic slot waveguide, and a dispersion analysis was carried out using the finite element method to study the effect of dopant concentration and waveguide geometry on the guided modes. Finite-difference time domain was used to simulate the transmission spectrum of the waveguide with air, methane and octane and the characteristic peaks in the IR spectra showed up strongly. This is a promising versatile method that can sense any IR-active gas.

  11. Various On-Chip Sensors with Microfluidics for Biological Applications

    Directory of Open Access Journals (Sweden)

    Hun Lee

    2014-09-01

    Full Text Available In this paper, we review recent advances in on-chip sensors integrated with microfluidics for biological applications. Since the 1990s, much research has concentrated on developing a sensing system using optical phenomena such as surface plasmon resonance (SPR and surface-enhanced Raman scattering (SERS to improve the sensitivity of the device. The sensing performance can be significantly enhanced with the use of microfluidic chips to provide effective liquid manipulation and greater flexibility. We describe an optical image sensor with a simpler platform for better performance over a larger field of view (FOV and greater depth of field (DOF. As a new trend, we review consumer electronics such as smart phones, tablets, Google glasses, etc. which are being incorporated in point-of-care (POC testing systems. In addition, we discuss in detail the current optical sensing system integrated with a microfluidic chip.

  12. On-chip data exchange for mode division multiplexed signals.

    Science.gov (United States)

    Ye, Mengyuan; Yu, Yu; Sun, Chunlei; Zhang, Xinliang

    2016-01-11

    Data exchange is an important function for flexible optical network, and it has been extensively investigated for the time and wavelength domains. The mode division multiplexing (MDM) has been proposed to further increase the transmission capacity by carrying information on different modes with only single wavelength carrier. We propose and experimentally demonstrate a novel on-chip data exchange circuit for the MDM signals by utilizing two micro-ring resonator (MRR) based mode converters. For demonstration, single and four wavelengths non-return-to-zero on-off-keying (NRZ-OOK) signals at 10 Gb/s carried on different modes are successfully processed, with open and clear eye diagrams. Measured bit error ratio (BER) results show reasonable power penalties. The proposed circuit can be potentially used in advanced and flexible MDM optical networks.

  13. On-chip generation of heralded photon-number states

    Science.gov (United States)

    Vergyris, Panagiotis; Meany, Thomas; Lunghi, Tommaso; Sauder, Gregory; Downes, James; Steel, M. J.; Withford, Michael J.; Alibart, Olivier; Tanzilli, Sébastien

    2016-01-01

    Beyond the use of genuine monolithic integrated optical platforms, we report here a hybrid strategy enabling on-chip generation of configurable heralded two-photon states. More specifically, we combine two different fabrication techniques, i.e., non-linear waveguides on lithium niobate for efficient photon-pair generation and femtosecond-laser-direct-written waveguides on glass for photon manipulation. Through real-time device manipulation capabilities, a variety of path-coded heralded two-photon states can be produced, ranging from product to entangled states. Those states are engineered with high levels of purity, assessed by fidelities of 99.5 ± 8% and 95.0 ± 8%, respectively, obtained via quantum interferometric measurements. Our strategy therefore stands as a milestone for further exploiting entanglement-based protocols, relying on engineered quantum states, and enabled by scalable and compatible photonic circuits. PMID:27775062

  14. An on-chip colloidal magneto-optical grating

    Science.gov (United States)

    Prikockis, M.; Wijesinghe, H.; Chen, A.; VanCourt, J.; Roderick, D.; Sooryakumar, R.

    2016-04-01

    Interacting nano- and micro-particles provide opportunities to create a wide range of useful colloidal and soft matter constructs. In this letter, we examine interacting superparamagnetic polymeric particles residing on designed permalloy (Ni0.8 Fe0.2) shapes that are subject to weak time-orbiting magnetic fields. The precessing field and magnetic barriers that ensue along the outer perimeter of the shapes allow for containment concurrent with independent field-tunable ordering of the dipole-coupled particles. These remotely activated arrays with inter-particle spacing comparable to the wavelength of light yield microscopic on-chip surface gratings for beam steering and magnetically regulated light diffraction applications.

  15. Photonic crystal biosensors towards on-chip integration.

    Science.gov (United States)

    Threm, Daniela; Nazirizadeh, Yousef; Gerken, Martina

    2012-08-01

    Photonic crystal technology has attracted large interest in the last years. The possibility to generate highly sensitive sensor elements with photonic crystal structures is very promising for medical or environmental applications. The low-cost fabrication on the mass scale is as advantageous as the compactness and reliability of photonic crystal biosensors. The possibility to integrate microfluidic channels together with photonic crystal structures allows for highly compact devices. This article reviews different types of photonic crystal sensors including 1D photonic crystal biosensors, biosensors with photonic crystal slabs, photonic crystal waveguide biosensors and biosensors with photonic crystal microcavities. Their applications in biomolecular and pathogen detection are highlighted. The sensitivities and the detection limits of the different biosensors are compared. The focus is on the possibilities to integrate photonic crystal biosensors on-chip.

  16. Spin Seebeck devices using local on-chip heating

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Stephen M., E-mail: swu@anl.gov; Fradin, Frank Y.; Hoffman, Jason; Hoffmann, Axel; Bhattacharya, Anand [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2015-05-07

    A micro-patterned spin Seebeck device is fabricated using an on-chip heater. Current is driven through a Au heater layer electrically isolated from a bilayer consisting of Fe{sub 3}O{sub 4} (insulating ferrimagnet) and a spin detector layer. It is shown that through this method it is possible to measure the longitudinal spin Seebeck effect (SSE) for small area magnetic devices, equivalent to traditional macroscopic SSE experiments. Using a lock-in detection technique, it is possible to more sensitively characterize both the SSE and the anomalous Nernst effect (ANE), as well as the inverse spin Hall effect in various spin detector materials. By using the spin detector layer as a thermometer, we can obtain a value for the temperature gradient across the device. These results are well matched to values obtained through electromagnetic/thermal modeling of the device structure and with large area spin Seebeck measurements.

  17. On-chip magnetometer for characterization of superparamagnetic nanoparticles.

    Science.gov (United States)

    Kim, Kun Woo; Reddy, Venu; Torati, Sri Ramulu; Hu, Xing Hao; Sandhu, Adarsh; Kim, Cheol Gi

    2015-02-07

    An on-chip magnetometer was fabricated by integrating a planar Hall magnetoresistive (PHR) sensor with microfluidic channels. The measured in-plane field sensitivities of an integrated PHR sensor with NiFe/Cu/IrMn trilayer structure were extremely high at 8.5 μV Oe(-1). The PHR signals were monitored during the oscillation of 35 pL droplets of magnetic nanoparticles, and reversed profiles for the positive and negative z-fields were measured, where magnitudes increased with the applied z-field strength. The measured PHR signals for 35 pL droplets of magnetic nanoparticles versus applied z-fields showed excellent agreement with magnetization curves measured by a vibrating sample magnetometer (VSM) of 3 μL volume, where a PHR voltage of 1 μV change is equivalent to 0.309 emu cc(-1) of the volume magnetization with a magnetic moment resolution of ~10(-10) emu.

  18. On-chip photonic Fourier transform with surface plasmon polaritons

    Institute of Scientific and Technical Information of China (English)

    Shan Shan Kou; Guanghui Yuan; Qian wang; Luping Du; Eugeniu Balaur; Daohua Zhang; Dingyuan Tang

    2016-01-01

    The Fourier transform (FT),a cornerstone of optical processing,enables rapid evaluation of fundamental mathematical operations,such as derivatives and integrals.Conventionally,a converging lens performs an optical FT in free space when light passes through it.The speed of the transformation is limited by the thickness and the focal length of the lens.By usingthe wave nature of surface plasmon polaritons (SPPs),here we demonstrate that the FT can be implemented in a planar configuration with a minimal propagation distance of around 10 μm,resulting in an increase of speed by four to five orders of magnitude.The photonic FT was tested by synthesizing intricate SPP waves with their Fourier components.The reduced dimensionality in the minuscule device allows the future development of an ultrafast on-chip photonic information processing platform for large-scale optical computing.

  19. Magnetic Tunnel Junction as an On-Chip Temperature Sensor.

    Science.gov (United States)

    Sengupta, Abhronil; Liyanagedera, Chamika Mihiranga; Jung, Byunghoo; Roy, Kaushik

    2017-09-18

    Temperature sensors are becoming an increasingly important component in System-on-Chip (SoC) designs with increasing transistor scaling, power density and associated heating effects. This work explores a compact nanoelectronic temperature sensor based on a Magnetic Tunnel Junction (MTJ) structure. The MTJ switches probabilistically depending on the operating temperature in the presence of thermal noise. Performance evaluation of the proposed MTJ temperature sensor, based on experimentally measured device parameters, reveals that the sensor is able to achieve a conversion rate of 2.5K samples/s with energy consumption of 8.8 nJ per conversion (1-2 orders of magnitude lower than state-of-the-art CMOS sensors) for a linear sensing regime of 200-400 K.

  20. Blood pressure control with selective vagal nerve stimulation and minimal side effects

    Science.gov (United States)

    Plachta, Dennis T. T.; Gierthmuehlen, Mortimer; Cota, Oscar; Espinosa, Nayeli; Boeser, Fabian; Herrera, Taliana C.; Stieglitz, Thomas; Zentner, Joseph

    2014-06-01

    Objective. Hypertension is the largest threat to patient health and a burden to health care systems. Despite various options, 30% of patients do not respond sufficiently to medical treatment. Mechanoreceptors in the aortic arch relay blood pressure (BP) levels through vagal nerve (VN) fibers to the brainstem and trigger the baroreflex, lowering the BP. Selective electrical stimulation of these nerve fibers reduced BP in rats. However, there is no technique described to localize and stimulate these fibers inside the VN without inadvertent stimulation of non-baroreceptive fibers causing side effects like bradycardia and bradypnea. Approach. We present a novel method for selective VN stimulation to reduce BP without the aforementioned side effects. Baroreceptor compound activity of rat VN (n = 5) was localized using a multichannel cuff electrode, true tripolar recording and a coherent averaging algorithm triggered by BP or electrocardiogram. Main results. Tripolar stimulation over electrodes near the barofibers reduced the BP without triggering significant bradycardia and bradypnea. The BP drop was adjusted to 60% of the initial value by varying the stimulation pulse width and duration, and lasted up to five times longer than the stimulation. Significance. The presented method is robust to impedance changes, independent of the electrode's relative position, does not compromise the nerve and can run on implantable, ultra-low power signal processors.

  1. Effect of transcutaneous electrical nerve stimulation for pain control after total knee arthroplasty: A systematic review and meta-analysis.

    Science.gov (United States)

    Zhu, Yongjun; Feng, Yuxing; Peng, Lihua

    2017-09-21

    Transcutaneous electrical nerve stimulation is a possible adjunctive therapy to pharmacological treatment for controlling pain after total knee arthroplasty. However, the results are controversial. A systematic review and meta-analysis was conducted to explore the effect of transcutaneous electrical nerve stimulation on patients with total knee arthroplasty. PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases were searched systematically. Randomized controlled trials assessing the effect of transcutaneous electrical nerve stimulation on patients with total knee arthroplasty were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. Primary outcome was visual analogue scale (VAS) score over a period of 24 h. Meta-analysis was performed using a random-effect model. Six randomized controlled trials involving 529 patients were included in the meta-analysis. Overall, compared with control intervention, transcutaneous electrical nerve stimulation supplementation intervention was found to significantly reduce VAS scores and total postoperative morphine dose over a period of 24 h, and to improve active range of knee motion (standard mean difference (SMD) = 0.37; 95% confidence interval (95% CI) = 0.06-0.68; p = 0.02), but had no effect on VAS scores at 2 weeks (SMD = 0.20; 95% CI = -0.07 to 0.48; p = 0.15). Compared with control intervention, transcutaneous electrical nerve stimulation supplementation intervention was found to significantly reduce pain and morphine requirement over a period of 24 h and to promote functional recovery in patients who have undergone total knee arthroplasty.

  2. Threshold electrical stimulation (TES) in ambulant children with CP: a randomized double-blind placebo-controlled clinical trial

    DEFF Research Database (Denmark)

    Dali, Christine í; Hansen, Flemming Juul; Pedersen, Søren Anker;

    2002-01-01

    A randomized double-blind placebo-controlled clinical trial was carried out to determine whether a group of stable children with cerebral palsy (36 males, 21 females; mean age 10 years 11 months, range 5 to 18 years) would improve their motor skills after 12 months of threshold electrical...... stimulation (TES). Two thirds received active and one third received inactive stimulators. For the primary outcome we constructed a set of plausible motor function tests and studied the change in summary indices of the performance measurements. Tests were videotaped and assessed blindly to record qualitative...

  3. Children peripheral facial palsy treated with three therapies of strong stimulation: a randomized controlled trial

    Institute of Scientific and Technical Information of China (English)

    曹文忠

    2013-01-01

    Objective To evaluate the clinical efficacy and safety of the three therapies of strong stimulation for children peripheral facial palsy so as to deal with the problem on the inactive acceptance of acupuncture in children.Methods Eighty cases of children peripheral facial palsy were randomized into a moxa stick group (group A) and a group with three therapies of strong stimulation (group B) .Baihui (GV 20) ,Sibai (ST 2) ,Dicang (ST 4) ,Jiache (ST 6) and the other acupoints were selected in the two groups and stimulated with half-needling technique.

  4. Development of a lab-on-chip electrochemical biosensor for water quality analysis based on microalgal photosynthesis.

    Science.gov (United States)

    Tsopela, A; Laborde, A; Salvagnac, L; Ventalon, V; Bedel-Pereira, E; Séguy, I; Temple-Boyer, P; Juneau, P; Izquierdo, R; Launay, J

    2016-05-15

    The present work was dedicated to the development of a lab-on-chip device for water toxicity analysis and more particularly herbicide detection in water. It consists in a portable system for on-site detection composed of three-electrode electrochemical microcells, integrated on a fluidic platform constructed on a glass substrate. The final goal is to yield a system that gives the possibility of conducting double, complementary detection: electrochemical and optical and therefore all materials used for the fabrication of the lab-on-chip platform were selected in order to obtain a device compatible with optical technology. The basic detection principle consisted in electrochemically monitoring disturbances in metabolic photosynthetic activities of algae induced by the presence of Diuron herbicide. Algal response, evaluated through oxygen (O2) monitoring through photosynthesis was different for each herbicide concentration in the examined sample. A concentration-dependent inhibition effect of the herbicide on photosynthesis was demonstrated. Herbicide detection was achieved through a range (blank - 1 µM Diuron herbicide solution) covering the limit of maximum acceptable concentration imposed by Canadian government (0.64 µM), using a halogen white light source for the stimulation of algal photosynthetic apparatus. Superior sensitivity results (limit of detection of around 0.1 µM) were obtained with an organic light emitting diode (OLED), having an emission spectrum adapted to algal absorption spectrum and assembled on the final system.

  5. "hCG priming" effect in controlled ovarian stimulation through a long protocol

    Directory of Open Access Journals (Sweden)

    Antsaklis Aris

    2009-08-01

    Full Text Available Abstract Background Recently, it has been demonstrated that, in patients down-regulated by GnRH analogues (GnRHa, a short-term pre-treatment with recombinant LH (rLH, prior to recombinant FSH (rFSH administration, increases the number of small antral follicle prior to FSH stimulation and the yield of normally fertilized embryos. However, no data exist in the literature regarding the potential beneficial effect of "hCG priming" in controlled ovarian hyperstimulation (COH through a long GnRH-a protocol, which binds the same receptor (LH/hCGR, though it is a much more potent compared to LH. The primary aims of this study were to assess the effect of short-term pre-rFSH administration of hCG in women entering an ICSI treatment cycle on follicular development, quality of oocytes and early embryo development. The secondary endpoints were to record the effects on endometrial quality and pregnancy rate. Methods Patients with a history of at least one previous unsuccessful ICSI cycle were randomly assigned into two groups to receive treatment with either a long protocol with rFSH (control group or a long protocol with rFSH and pre-treatment with hCG (hCG group. In particular, in the latter group, a fixed 7 days course of 200 IU/day hCG was administered as soon as pituitary desensitization was confirmed. Results The mean number of oocytes retrieved was not significantly different between the two treatment groups, although the percentage of mature oocytes tended to be higher but not significantly different in hCG-treated patients. The percentage of patients with more than one grade 3 embryos was higher in the pre-treatment group, which also showed a higher pregnancy rate. Conclusion All the above clinical observations, in conjunction with previous data, suggest a point towards a beneficial "hCG priming" effect in controlled ovarian hyperstimulation through a long GnRH-a down-regulation protocol, particularly in patients with previous ART failures.

  6. A novel functional electrical stimulation-control system for restoring motor function of post-stroke hemiplegic patients

    Institute of Scientific and Technical Information of China (English)

    Zonghao Huang; Zhigong Wang; Xiaoying Lv; Yuxuan Zhou; Haipeng Wang; Sihao Zong

    2014-01-01

    Hemiparesis is one of the most common consequences of stroke. Advanced rehabilitation tech-niques are essential for restoring motor function in hemiplegic patients. Functional electrical stimulation applied to the affected limb based on myoelectric signal from the unaffected limb is a promising therapy for hemiplegia. In this study, we developed a prototype system for evaluating this novel functional electrical stimulation-control strategy. Based on surface electromyography and a vector machine model, a self-administered, multi-movement, force-modulation functional electrical stimulation-prototype system for hemiplegia was implemented. This paper discusses the hardware design, the algorithm of the system, and key points of the self-oscillation-prone system. The experimental results demonstrate the feasibility of the prototype system for further clinical trials, which is being conducted to evaluate the efifcacy of the proposed rehabilitation technique.

  7. MUNIX and incremental stimulation MUNE in ALS patients and control subjects

    DEFF Research Database (Denmark)

    Furtula, Jasna; Johnsen, Birger; Christensen, Peter Broegger

    2013-01-01

    This study compares the new Motor Unit Number Estimation (MUNE) technique, MUNIX, with the more common incremental stimulation MUNE (IS-MUNE) with respect to reproducibility in healthy subjects and as potential biomarker of disease progression in patients with ALS....

  8. Genetic control of conventional and pheromone-stimulated biofilm formation in Candida albicans.

    Science.gov (United States)

    Lin, Ching-Hsuan; Kabrawala, Shail; Fox, Emily P; Nobile, Clarissa J; Johnson, Alexander D; Bennett, Richard J

    2013-01-01

    Candida albicans can stochastically switch between two phenotypes, white and opaque. Opaque cells are the sexually competent form of C. albicans and therefore undergo efficient polarized growth and mating in the presence of pheromone. In contrast, white cells cannot mate, but are induced - under a specialized set of conditions - to form biofilms in response to pheromone. In this work, we compare the genetic regulation of such "pheromone-stimulated" biofilms with that of "conventional" C. albicans biofilms. In particular, we examined a network of six transcriptional regulators (Bcr1, Brg1, Efg1, Tec1, Ndt80, and Rob1) that mediate conventional biofilm formation for their potential roles in pheromone-stimulated biofilm formation. We show that four of the six transcription factors (Bcr1, Brg1, Rob1, and Tec1) promote formation of both conventional and pheromone-stimulated biofilms, indicating they play general roles in cell cohesion and biofilm development. In addition, we identify the master transcriptional regulator of pheromone-stimulated biofilms as C. albicans Cph1, ortholog of Saccharomyces cerevisiae Ste12. Cph1 regulates mating in C. albicans opaque cells, and here we show that Cph1 is also essential for pheromone-stimulated biofilm formation in white cells. In contrast, Cph1 is dispensable for the formation of conventional biofilms. The regulation of pheromone- stimulated biofilm formation was further investigated by transcriptional profiling and genetic analyses. These studies identified 196 genes that are induced by pheromone signaling during biofilm formation. One of these genes, HGC1, is shown to be required for both conventional and pheromone-stimulated biofilm formation. Taken together, these observations compare and contrast the regulation of conventional and pheromone-stimulated biofilm formation in C. albicans, and demonstrate that Cph1 is required for the latter, but not the former.

  9. MUNIX and incremental stimulation MUNE in ALS patients and control subjects

    DEFF Research Database (Denmark)

    Furtula, Jasna; Johnsen, Birger; Christensen, Peter Broegger;

    2013-01-01

    This study compares the new Motor Unit Number Estimation (MUNE) technique, MUNIX, with the more common incremental stimulation MUNE (IS-MUNE) with respect to reproducibility in healthy subjects and as potential biomarker of disease progression in patients with ALS.......This study compares the new Motor Unit Number Estimation (MUNE) technique, MUNIX, with the more common incremental stimulation MUNE (IS-MUNE) with respect to reproducibility in healthy subjects and as potential biomarker of disease progression in patients with ALS....

  10. Transcranial direct current stimulation in refractory continuous spikes and waves during slow sleep: a controlled study

    DEFF Research Database (Denmark)

    Varga, Edina T; Terney, Daniella; Atkins, Mary D;

    2011-01-01

    Cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability. The purpose of the study was to investigate whether cathodal tDCS could interrupt the continuous epileptiform activity. Five patients with focal, refractory continuous spikes and waves during slow sleep were...... recruited. Cathodal tDCS and sham stimulation were applied to the epileptic focus, before sleep (1 mA; 20 min). Cathodal tDCS did not reduce the spike-index in any of the patients....

  11. Neural signal processing and closed-loop control algorithm design for an implanted neural recording and stimulation system.

    Science.gov (United States)

    Hamilton, Lei; McConley, Marc; Angermueller, Kai; Goldberg, David; Corba, Massimiliano; Kim, Louis; Moran, James; Parks, Philip D; Sang Chin; Widge, Alik S; Dougherty, Darin D; Eskandar, Emad N

    2015-08-01

    A fully autonomous intracranial device is built to continually record neural activities in different parts of the brain, process these sampled signals, decode features that correlate to behaviors and neuropsychiatric states, and use these features to deliver brain stimulation in a closed-loop fashion. In this paper, we describe the sampling and stimulation aspects of such a device. We first describe the signal processing algorithms of two unsupervised spike sorting methods. Next, we describe the LFP time-frequency analysis and feature derivation from the two spike sorting methods. Spike sorting includes a novel approach to constructing a dictionary learning algorithm in a Compressed Sensing (CS) framework. We present a joint prediction scheme to determine the class of neural spikes in the dictionary learning framework; and, the second approach is a modified OSort algorithm which is implemented in a distributed system optimized for power efficiency. Furthermore, sorted spikes and time-frequency analysis of LFP signals can be used to generate derived features (including cross-frequency coupling, spike-field coupling). We then show how these derived features can be used in the design and development of novel decode and closed-loop control algorithms that are optimized to apply deep brain stimulation based on a patient's neuropsychiatric state. For the control algorithm, we define the state vector as representative of a patient's impulsivity, avoidance, inhibition, etc. Controller parameters are optimized to apply stimulation based on the state vector's current state as well as its historical values. The overall algorithm and software design for our implantable neural recording and stimulation system uses an innovative, adaptable, and reprogrammable architecture that enables advancement of the state-of-the-art in closed-loop neural control while also meeting the challenges of system power constraints and concurrent development with ongoing scientific research designed

  12. A controlled comparison of ovarian response to controlled stimulation in first generation Asian women compared with white Caucasians undergoing in vitro fertilisation.

    Science.gov (United States)

    Lashen, H; Afnan, M; Sharif, K

    1999-05-01

    To compare ovarian response to controlled stimulation among Asian women from the Indian sub-continent and white Caucasian women undergoing in vitro fertilisation (IVF). Nested case-control study. Assisted Conception Unit, Birmingham Women's Hospital. One hundred and eight first generation Asian patients (born in the Indian sub-continent) and 216 white Caucasian controls, all of whom received IVF treatment in the period 1994 to 1997, were selected for the study. The two groups were matched for age to within one year, early follicular phase follicle stimulating hormone, indication for treatment, gonadotrophin dose and year of treatment. The outcome of treatment was not known when the controls were selected. There was no statistically significant difference between the two groups in the duration of stimulation, egg number, number of embryos produced, fertilisation rate, clinical pregnancy rate, miscarriage rate, cycle cancellation rate and implantation rate. Under the same IVF protocol Asian women's response to controlled ovarian stimulation and IVF outcome are comparable to their white Caucasian peers.

  13. A novel magnetic stimulator increases experimental pain tolerance in healthy volunteers - a double-blind sham-controlled crossover study.

    Directory of Open Access Journals (Sweden)

    Rudie Kortekaas

    Full Text Available UNLABELLED: The 'complex neural pulse'(TM (CNP is a neuromodulation protocol employing weak pulsed electromagnetic fields (PEMF. A pioneering paper reported an analgesic effect in healthy humans after 30 minutes of CNP-stimulation using three nested whole head coils. We aimed to devise and validate a stimulator with a novel design entailing a multitude of small coils at known anatomical positions on a head cap, to improve applicability. The main hypothesis was that CNP delivery with this novel device would also increase heat pain thresholds. Twenty healthy volunteers were enrolled in this double-blind, sham-controlled, crossover study. Thirty minutes of PEMF (CNP or sham was applied to the head. After one week the other treatment was given. Before and after each treatment, primary and secondary outcomes were measured. Primary outcome was heat pain threshold (HPT measured with thermal quantitative sensory testing. Other outcomes were warmth detection threshold, and aspects of cognition, emotion and motor performance. As hypothesized heat pain threshold was significantly increased after the PEMF stimulation. All other outcomes were unaltered by the PEMF but there was a trend level reduction of cognitive performance after PEMF stimulation as measured by the digit-symbol substitution task. Results from this pilot study suggest that our device is able to stimulate the brain and to modulate its function. This is in agreement with previous studies that used similar magnetic field strengths to stimulate the brain. Specifically, pain control may be achieved with PEMF and for this analgesic effect, coil design does not appear to play a dominant role. In addition, the flexible configuration with small coils on a head cap improves clinical applicability. TRIAL REGISTRATION: Dutch Cochrane Centre NTR1093.

  14. Viral and therapeutic control of IFN-β promoter stimulator 1 during hepatitis C virus infection

    Science.gov (United States)

    Loo, Yueh-Ming; Owen, David M.; Li, Kui; Erickson, Andrea K.; Johnson, Cynthia L.; Fish, Penny M.; Carney, D. Spencer; Wang, Ting; Ishida, Hisashi; Yoneyama, Mitsutoshi; Fujita, Takashi; Saito, Takeshi; Lee, William M.; Hagedorn, Curt H.; Lau, Daryl T.-Y.; Weinman, Steven A.; Lemon, Stanley M.; Gale, Michael

    2006-01-01

    Viral signaling through retinoic acid-inducible gene-I (RIG-I) and its adaptor protein, IFN promoter-stimulator 1 (IPS-1), activates IFN regulatory factor-3 (IRF-3) and the host IFN-α/β response that limits virus infection. The hepatitis C virus (HCV) NS3/4A protease cleaves IPS-1 to block RIG-I signaling, but how this regulation controls the host response to HCV is not known. Moreover, endogenous IPS-1 cleavage has not been demonstrated in the context of HCV infection in vitro or in vivo. Here, we show that HCV infection transiently induces RIG-I- and IPS-1-dependent IRF-3 activation. This host response limits HCV production and constrains cellular permissiveness to infection. However, HCV disrupts this response early in infection by NS3/4A cleavage of IPS-1 at C508, releasing IPS-1 from the mitochondrial membrane. Cleavage results in subcellular redistribution of IPS-1 and loss of interaction with RIG-I, thereby preventing downstream activation of IRF-3 and IFN-β induction. Liver tissues from chronically infected patients similarly demonstrate subcellular redistribution of IPS-1 in infected hepatocytes and IPS-1 cleavage associated with a lack of ISG15 expression and conjugation of target proteins in vivo. Importantly, small-molecule inhibitors of NS3/4A prevent cleavage and restore RIG-I signaling of IFN-β induction. Our results suggest a dynamic model in which early activation of IRF-3 and induction of antiviral genes are reversed by IPS-1 proteolysis and abrogation of RIG-I signaling as NS3/4A accumulates in newly infected cells. HCV protease inhibitors effectively prevent IPS-1 proteolysis, suggesting they may be capable of restoring this innate host response in clinical practice. PMID:16585524

  15. Advanced Nanofabrication Process Development for Self-Powered System-on-Chip

    KAUST Repository

    Rojas, Jhonathan Prieto

    2010-11-01

    In this work the development of a Self-Powered System-On-Chip is explored by examining two components of process development in different perspectives. On one side, an energy component is approached from a biochemical standpoint where a Microbial Fuel Cell (MFC) is built with standard microfabrication techniques, displaying a novel electrode based on Carbon Nanotubes (CNTs). The fabrication process involves the formation of a micrometric chamber that hosts an enhanced CNT-based anode. Preliminary results are promising, showing a high current density (113.6mA/m2) compared with other similar cells. Nevertheless many improvements can be done to the main design and further characterization of the anode will give a more complete understanding and bring the device closer to a practical implementation. On a second point of view, nano-patterning through silicon nitride spacer width control is developed, aimed at producing alternative sub-100nm device fabrication with the potential of further scaling thanks to nanowire based structures. These nanostructures are formed from a nano-pattern template, by using a bottom-up fabrication scheme. Uniformity and scalability of the process are demonstrated and its potential described. An estimated area of 0.120μm2 for a 6T-SRAM (Static Random Access Memory) bitcell (6 devices) can be achieved. In summary, by using a novel sustainable energy component and scalable nano-patterning for logic and computing module, this work has successfully collected the essential base knowledge and joined two different elements that synergistically will contribute for the future implementation of a Self-Powered System-on-Chip.

  16. Subject-controlled, on-demand, dorsal genital nerve stimulation to treat urgency urinary incontinence, a pilot.

    Directory of Open Access Journals (Sweden)

    Hendrikje eVan Breda

    2016-02-01

    Full Text Available ObjectivesTo evaluate the effect of subject-controlled, on-demand, dorsal genital nerve stimulation on non-neurogenic urgency urinary incontinence in a domestic setting.Materials and MethodsNon-neurogenic patients >18 years with overactive bladder symptoms and urgency urinary incontinence were included. Exclusion criteria were mainly stress urinary incontinence. Patients underwent one week of subject-controlled, on-demand, dorsal genital nerve stimulation, delivered by a percutaneously placed electrode near the dorsal genital nerve connected to an external stimulator (pulse-rate 20 Hz, pulse-width 300 μs. Patients activated the stimulator when feeling the urge to void and stimulated for 30 s. The amplitude was set at the highest tolerable level. A bladder diary including a severity score of the urgency urinary incontinence episodes/void (scores: 0=none, 1=drops, 2=dashes, 3=soaks and a padtest was kept 3 days prior to, during, and 3 days after the test period. The subjective improvement was also scored.ResultsSeven patients (4 males / 3 females were enrolled, the mean age was 55 years (range 23-73. Six completed the test week. In the remaining patient the electrode migrated and was removed. 5/6 finalized the complete bladder diary, 1/6 recorded only the heavy incontinence episodes (score=3. 4/6 completed the padtest. In all patients who finalized the bladder diary the number of urgency urinary incontinence episodes decreased, in 3/5 with ≥60%. The heavy incontinence episodes (score=3 were resolved in 2/6 patients, and improved ≥ 80% in the other 4. The severity score of the urgency urinary incontinence episodes/void was improved with ≥60% in 3/5 patients. The mean subjective improvement was 73%. ConclusionThis feasibility study indicates that subject-controlled, on-demand dorsal genital nerve stimulation using a percutaneously placed electrode is possible over a longer time period, in a home setting, with a positive effect on non

  17. Efficacies of globus pallidus stimulation and subthalamic nucleus stimulation for advanced Parkinson's disease: a meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Tan ZG

    2016-06-01

    Full Text Available Zhi-Gang Tan, Qian Zhou, Tao Huang, Yugang JiangDepartment of Neurosurgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, People’s Republic of ChinaObjectives: Deep brain stimulation (DBS is the surgical procedure for patients with advanced Parkinson’s disease. Globus pallidus internus (GPi and subthalamic nucleus (STN are the most targeted locations for the procedure. To investigate the variable efficiencies for the two different locations, we conducted a meta-analysis to compare both stimulation sites.Materials and methods: A systematic search was performed in PubMed, Embase, and the Cochrane Library databases. Randomized controlled trials comparing the efficacies of GPi and STN DBS were included. Clinical outcomes of motor function, nonmotor function, and quality of life (QOL were collected for the meta-analysis.Results: Ten eligible trials with 1,034 patients were included in the analysis. Unified Parkinson’s disease rating scale III (UPDRS-III scores were collected at 6, 12, and 24 months postsurgery separately to assess the motor function of the patients. A statistically significant effect in favor of the GPi DBS was obtained in the off-medication/on-stimulation phase of UPDRS-III at 12 months (mean difference [MD] =6.87, 95% confidence interval [95% CI]: 3.00–10.74, P=0.57, I2=0%. However, GPi DBS showed an opposite result at 24 months (MD =−2.46, 95% CI: −4.91 to −0.02, P=0.05, I2=0%. In the on-medication/on-stimulation phase, GPi DBS obtained a worse outcome compared with STN DBS (MD =−2.90, 95% CI: −5.71 to −0.09, P=0.05, I2=0%. Compared with STN DBS, increased dosage of levodopa equivalent doses was needed in GPi DBS (standardized MD =0.60, 95% CI: 0.46–0.74, P<0.00001, I2=24%. Meanwhile, Beck Depression Inventory II scores demonstrated that STN has a better performance (standardized MD =−0.31, 95% CI: −0.51 to −0.12, P=0.002, I2=0%. As for neurocognitive phase postsurgery

  18. Tunable narrowband microwave photonic filter created by stimulated Brillouin scattering from a Silicon nanowire

    CERN Document Server

    Casas-Bedoya, Alvaro; Pagani, Mattia; Marpaung, David; Eggleton, Benjamin J

    2015-01-01

    We demonstrate the first functional signal processing device based on stimulated Brillouin scattering in a silicon nanowire. We use only 1 dB of on-chip SBS gain to create an RF photonic notch filter with 48 dB of suppression, 98 MHz linewidth, and 6 GHz frequency tuning. This device has potential applications in on-chip microwave signal processing and establishes the foundation for the first CMOS-compatible high performance RF photonic filter.

  19. Selective autonomic stimulation of the AV node fat pad to control rapid post-operative atrial arrhythmias.

    Science.gov (United States)

    Mercader, Marco A; He, Dingchao; Sharma, Aditya C; Marchitto, Mark C; Trachiotis, Gregory; Bornzin, Gene A; Jonas, Richard; Moak, Jeffrey P

    2017-01-01

    Junctional ectopic tachycardia (JET) and atrial fibrillation (AF) occur in patients recovering from open-heart surgery (OHS). Pharmacologic treatment is used for the control of post-operative atrial arrhythmias (POAA), but is associated with side effects. There is a need for a reversible, modulated solution to rate control. We propose a non-pharmacologic technique that can modulate AV nodal conduction in a selective fashion. Ten mongrel dogs underwent OHS. Stimulation of the anterior right (AR) and inferior right (IR) fat pad (FP) was done using a 7-pole electrode. The IR was more effective in slowing the ventricular rate (VR) to AF (52 +/- 20 vs. 15 +/- 10%, p = 0.003) and JET (12 +/- 7 vs. 0 +/- 0%, p = 0.02). Selective site stimulation within a FP region could augment the effect of stimulation during AF (57 +/- 20% (maximum effect) vs. 0 +/- 0% (minimum effect), pAV node fat pad stimulation had a selective effect on the AV node by decreasing AV nodal conduction, with little effect on atrial activity.

  20. Transcutaneous noninvasive vagus nerve stimulation (tVNS) in the treatment of schizophrenia: a bicentric randomized controlled pilot study.

    Science.gov (United States)

    Hasan, Alkomiet; Wolff-Menzler, Claus; Pfeiffer, Sebastian; Falkai, Peter; Weidinger, Elif; Jobst, Andrea; Hoell, Imke; Malchow, Berend; Yeganeh-Doost, Peyman; Strube, Wolfgang; Quast, Silke; Müller, Norbert; Wobrock, Thomas

    2015-10-01

    Despite many pharmacological and psychosocial treatment options, schizophrenia remains a debilitating disorder. Thus, new treatment strategies rooted in the pathophysiology of the disorder are needed. Recently, vagus nerve stimulation (VNS) has been proposed as a potential treatment option for various neuropsychiatric disorders including schizophrenia. The objective of this study was to investigate for the first time the feasibility, safety and efficacy of transcutaneous VNS in stable schizophrenia. A bicentric randomized, sham-controlled, double-blind trial was conducted from 2010 to 2012. Twenty schizophrenia patients were randomly assigned to one of two treatment groups. The first group (active tVNS) received daily active stimulation of the left auricle for 26 weeks. The second group (sham tVNS) received daily sham stimulation for 12 weeks followed by 14 weeks of active stimulation. Primary outcome was defined as change in the Positive and Negative Symptom Scale total score between baseline and week 12. Various other secondary measures were assessed to investigate safety and efficacy. The intervention was well tolerated with no relevant adverse effects. We could not observe a statistically significant difference in the improvement of schizophrenia psychopathology during the observation period. Neither psychopathological and neurocognitive measures nor safety measures showed significant differences between study groups. Application of tVNS was well tolerated, but did not improve schizophrenia symptoms in our 26-week trial. While unsatisfactory compliance questions the feasibility of patient-controlled neurostimulation in schizophrenia, the overall pattern of symptom change might warrant further investigations in this population.

  1. Hybrid Neuroprosthesis for the Upper Limb: Combining Brain-Controlled Neuromuscular Stimulation with a Multi-Joint Arm Exoskeleton.

    Science.gov (United States)

    Grimm, Florian; Walter, Armin; Spüler, Martin; Naros, Georgios; Rosenstiel, Wolfgang; Gharabaghi, Alireza

    2016-01-01

    Brain-machine interface-controlled (BMI) neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion (ROM) and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES) is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related ROM and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton) in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. NMES was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD) and electromyography (EMG) activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e., induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p = 0.028) or EMG (p = 0.021) modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related ROM (p = 0.009) and the movement-related brain modulation (p = 0.019). Combining a hybrid BMI with neuromuscular stimulation

  2. A Randomized, Double-Blind, Sham-Controlled Trial of Transcranial Direct Current Stimulation in Attention-Deficit/Hyperactivity Disorder.

    Directory of Open Access Journals (Sweden)

    Camila Cosmo

    Full Text Available Current standardized treatments for cognitive impairment in attention-deficit/hyperactivity disorder remain limited and their efficacy restricted. Transcranial direct current stimulation (tDCS is a promising tool for enhancing cognitive performance in several neuropsychiatric disorders. Nevertheless, the effects of tDCS in reducing cognitive impairment in patients with attention-deficit/hyperactivity disorder (ADHD have not yet been investigated.A parallel, randomized, double-blind, sham-controlled trial was conducted to examine the efficacy of tDCS on the modulation of inhibitory control in adults with ADHD. Thirty patients were randomly allocated to each group and performed a go/no-go task before and after a single session of either anodal stimulation (1 mA over the left dorsolateral prefrontal cortex or sham stimulation.A nonparametric two-sample Wilcoxon rank-sum (Mann-Whitney test revealed no significant differences between the two groups of individuals with ADHD (tDCS vs. sham in regard to behavioral performance in the go/no go tasks. Furthermore, the effect sizes of group differences after treatment for the primary outcome measures-correct responses, impulsivity and omission errors--were small. No adverse events resulting from stimulation were reported.According to these findings, there is no evidence in support of the use of anodal stimulation over the left dorsolateral prefrontal cortex as an approach for improving inhibitory control in ADHD patients. To the best of our knowledge, this is the first clinical study to assess the cognitive effects of tDCS in individuals with ADHD. Further research is needed to assess the clinical efficacy of tDCS in this population.ClinicalTrials.gov NCT01968512.

  3. Short-term androgen priming by use of aromatase inhibitor and hCG before controlled ovarian stimulation for IVF. A randomized controlled trial

    DEFF Research Database (Denmark)

    Lossl, K; Andersen, C Yding; Loft, A;

    2008-01-01

    Temporary exposure of follicles to increased levels of androgens may augment follicular responsiveness. The present study tested whether short-term androgen priming by aromatase inhibitor and human chorionic gonadotrophin (hCG) before controlled ovarian stimulation (COS) increases the number of top...

  4. Reflex control of locomotion as revealed by stimulation of cutaneous afferents in spontaneously walking premammillary cats.

    Science.gov (United States)

    Duysens, J

    1977-07-01

    1. Stimulation of different hindlimb nerves in spontaneously walking premammillary cats was used in order to examine the effects of sensory input on the rhythmic motor output. 2. Stimulation of the tibial or sural nerve at low intensities caused the burst of activity in the triceps surae or semimembranosus to be prolonged if stimuli were given during the extension phase. When applied during the flexion phase, the same stimuli shortened the burst of activity in the pretibial flexors and induced an early onset of the extensor activity, except if stimuli were given at the very beginning of the flexion phase, when flexor burst prolongations or rebounds were observed instead. 3. These effects were related to activation of large cutaneous afferents in these nerves since the results could be duplicated by low-intensity stimulation of the tibial nerve at the ankle or by direct stimulation of the pad. 4. In contrast, activation of smaller afferents by high-intensity stimulation resulted prolongations of the flexor burst and/or shortenings of the extensor burst for stimuli applied before or during these bursts, respectively. 5. It was concluded that the large and small cutaneous afferents make, respectively, inhibitory and excitatory connections with the central structure involved in the generation of flexion during walking.

  5. Acupoint Stimulation for Fibromyalgia: A Systematic Review of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Huijuan Cao

    2013-01-01

    Full Text Available Background. Acupoint stimulation is popular for treatment of fibromyalgia though there is lack of comprehensive evaluation of current clinical evidence for its effect and safety. Objective. To systematically review the beneficial effects and safety of acupoint stimulation for fibromyalgia. Methods. We searched six electronic databases for randomized trials on acupoint stimulation for treatment of fibromyalgia. Two authors extracted data and assessed the trial quality independently. RevMan 5.2 software was used for data analyses with effect estimate presented as (standard mean difference and a 95% confidence interval. We defined minimum, medium, and large SMD effect sizes as 0.3, 0.5, and 0.75. Results. 16 RCTs with 1081 participants were involved in this review. Only two trials were evaluated as low risk of bias. Meta-analysis showed that acupuncture alone or combined with cupping therapy was superior to conventional medications on reducing pain scores and/or the number of tender points. However, acupuncture showed no better than sham acupuncture on pain reduction. There was no serious adverse event reported to be related to acupoint stimulation. Conclusions. Acupoint stimulation appears to be effective in treating fibromyalgia compared with medications. However, further large, rigorously designed trials are warranted due to insufficient methodological rigor in the included trials.

  6. Scattering detection using a photonic-microfluidic integrated device with on-chip collection capabilities.

    Science.gov (United States)

    Watts, Benjamin R; Zhang, Zhiyi; Xu, Chang Qing; Cao, Xudong; Lin, Min

    2014-02-01

    SU-8-based photonic-microfluidic integrated devices with on-chip beam shaping and collection capabilities were demonstrated in a scattering detection and counting application. Through the proper deployment of the tailored beam geometries via the on-chip excitation optics, excellent CV values were measured for 1, 2, and 5 μm blank beads, 16.4, 11.0, and 12.5%, respectively, coupled with a simple free-space optical detection scheme. The performance of these devices was found dependent on the combination of on-chip, lens-shaped beam geometry and bead size. While very low CVs were obtained when the combination was ideal, a nonideal combination could still result in acceptable CVs for flow cytometry; the reliability was confirmed via devices being able to resolve separate populations of 2.0 and 5.0 μm beads from their mixture with low CV values of 15.9 and 18.5%, respectively. On-chip collection using integrated on-chip optical waveguides was shown to be very reliable in comparison with a free-space collection scheme, yielding a coincident rate of 94.2%. A CV as low as 19.2% was obtained from the on-chip excitation and collection of 5 μm beads when the on-chip lens-shaped beam had a 6.0-μm beam waist.

  7. A tetrachromatic display for the spatiotemporal control of rod and cone stimulation.

    Science.gov (United States)

    Bayer, Florian S; Paulun, Vivian C; Weiss, David; Gegenfurtner, Karl R

    2015-08-01

    We present an apparatus that allows independent stimulation of rods and short (S)-, middle (M)-, and long (L)-wavelength-sensitive cones. Previously presented devices allow rod and cone stimulation independently, but only for a spatially invariant stimulus design (Pokorny, Smithson, & Quinlan, 2004; Sun, Pokorny, & Smith, 2001b). We overcame this limitation by using two spectrally filtered projectors with overlapping projections. This approach allows independent rod and cone stimulation in a dynamic two-dimensional scene with appropriate resolution in the spatial, temporal, and receptor domains. Modulation depths were ±15% for M-cones and L-cones, ±20% for rods, and ±50% for S-cones, all with respect to an equal-energy mesopic background at 3.4 cd/m2. Validation was provided by radiometric measures and behavioral data from two trichromats, one protanope, one deuteranope, and one night-blind observer.

  8. Co-design of on-chip antennas and circuits for a UNII band monolithic transceiver

    KAUST Repository

    Shamim, Atif

    2012-07-28

    The surge of highly integrated and multifunction wireless devices has necessitated the designers to think outside the box for solutions that are unconventional. The new trends have provided the impetus for low cost and compact RF System-on-Chip (SoC) approaches [1]. The major advantages of SoC are miniaturization and cost reduction. A major bottleneck to the true realization of monolithic RF SoC transceivers is the implementation of on-chip antennas with circuitry. Though complete integrated transceivers with on-chip antennas have been demonstrated, these designs are generally for high frequencies. Moreover, they either use non-standard CMOS processes or additional fabrication steps to enhance the antenna efficiency, which in turn adds to the cost of the system [2-3]. Another challenge related to the on-chip antennas is the characterization of their radiation properties. Most of the recently reported work (summarized in Table I) shows that very few on-chip antennas are characterized. Our previous work [4], demonstrated a Phase Lock Loop (PLL) based transmitter (TX) with an on-chip antenna. However, the radiation from the on-chip antenna experienced strong interference due to 1) some active circuitry on one side of the chip and 2) the PCB used to mount the chip in the anechoic chamber. This paper presents, for the first time, a complete 5.2 GHz (UNII band) transceiver with separate TX and receiver (RX) antennas. To the author\\'s best knowledge, its size of 3 mm2 is the smallest reported for a UNII band transceiver with two on-chip antennas. Both antennas are characterized for their radiation properties through an on-wafer custom measurement setup. The strategy to co-design on-chip antennas with circuits, resultant trade-offs and measurement challenges have also been discussed. © 2010 IEEE.

  9. [Transcranial alternating current stimulation. Entrainment and function control of neuronal networks].

    Science.gov (United States)

    Vosskuhl, J; Strüber, D; Herrmann, C S

    2015-12-01

    Transcranial alternating current stimulation (tACS) is a new technique for the modulation of oscillatory brain activity as measured in the electroencephalogram (EEG). In contrast to well-established stimulation techniques, such as transcranial direct current stimulation and transcranial magnetic stimulation, tACS applies a sinusoidal alternating current at a specific frequency. This enables the modulation of the amplitude and frequency of endogenous brain oscillations as well as related cognitive processes. Therefore, the use of tACS has the possibility to evaluate well-known correlations between brain oscillations and cognitive processes in terms of causality. Such causal relationships have been documented in numerous neurocognitive studies on sensory, motor and perceptual processes; however, the clinical application of tACS is still in its infancy. In principle, any pathology that can reliably be connected with brain oscillations of a defined frequency is treatable. A current main focus of clinical research is on symptoms of Parkinson's disease and to a lesser degree, tinnitus. For an effective application of tACS it is important to choose the electrode positions as well as the frequency, intensity and duration of the stimulation in a theory-based and symptom-related manner. A successful therapeutic intervention requires the persistence of the tACS effect after stimulation has ceased. A mechanism that offers not only an explanation to the origin of persistent tACS effects but is also of high therapeutic benefit is neural plasticity. Therefore, one current focus of research aims at a better understanding of tACS after effects.

  10. Adaptive digital calibration techniques for narrow band low-IF receivers with on-chip PLL

    Institute of Scientific and Technical Information of China (English)

    Li Juan; Zhang Huajiang; Zhao Feng; Hong Zhiliang

    2009-01-01

    Digital calibration and control techniques for narrow band integrated low-IF receivers with on-chip frequency synthesizer are presented. The calibration and control system, which is adopted to ensure an achievable signal-to-noise ratio and bit error rate, consists of a digitally controlled, high resolution dB-linear automatic gain control (AGC), an inphase (I) and quadrature (Q) gain and phase mismatch calibration, and an automatic frequency calibration (AFC) of a wideband voltage-controlled oscillator in a PLL based frequency synthesizer. The calibration system has a low design complexity with little power and small die area. Simulation results show that the calibration system can enlarge the dynamic range to 72 dB and minimize the phase and amplitude imbalance between I and Q to 0.08° and 0.024 dB, respectively, which means the image rejection ratio is better than 60 dB. In addition, the calibration time of the AFC is 1.12μs only with a reference clock of 100 MHz.

  11. A lab-on-chip for malaria diagnosis and surveillance.

    Science.gov (United States)

    Taylor, Brian J; Howell, Anita; Martin, Kimberly A; Manage, Dammika P; Gordy, Walter; Campbell, Stephanie D; Lam, Samantha; Jin, Albert; Polley, Spencer D; Samuel, Roshini A; Atrazhev, Alexey; Stickel, Alex J; Birungi, Josephine; Mbonye, Anthony K; Pilarski, Linda M; Acker, Jason P; Yanow, Stephanie K

    2014-05-09

    Access to timely and accurate diagnostic tests has a significant impact in the management of diseases of global concern such as malaria. While molecular diagnostics satisfy this need effectively in developed countries, barriers in technology, reagent storage, cost and expertise have hampered the introduction of these methods in developing countries. In this study a simple, lab-on-chip PCR diagnostic was created for malaria that overcomes these challenges. The platform consists of a disposable plastic chip and a low-cost, portable, real-time PCR machine. The chip contains a desiccated hydrogel with reagents needed for Plasmodium specific PCR. Chips can be stored at room temperature and used on demand by rehydrating the gel with unprocessed blood, avoiding the need for sample preparation. These chips were run on a custom-built instrument containing a Peltier element for thermal cycling and a laser/camera setup for amplicon detection. This diagnostic was capable of detecting all Plasmodium species with a limit of detection for Plasmodium falciparum of 2 parasites/μL of blood. This exceeds the sensitivity of microscopy, the current standard for diagnosis in the field, by ten to fifty-fold. In a blind panel of 188 patient samples from a hyper-endemic region of malaria transmission in Uganda, the diagnostic had high sensitivity (97.4%) and specificity (93.8%) versus conventional real-time PCR. The test also distinguished the two most prevalent malaria species in mixed infections, P. falciparum and Plasmodium vivax. A second blind panel of 38 patient samples was tested on a streamlined instrument with LED-based excitation, achieving a sensitivity of 96.7% and a specificity of 100%. These results describe the development of a lab-on-chip PCR diagnostic from initial concept to ready-for-manufacture design. This platform will be useful in front-line malaria diagnosis, elimination programmes, and clinical trials. Furthermore, test chips can be adapted to detect other

  12. Surface Potential Control on Thin Oxide Films with Respect to Electron Stimulated Desorption Studies

    Science.gov (United States)

    Bernheim, Marc; Rousse, Gilles

    1995-09-01

    These experiments deal with the study of desorption of negative ions stimulated by low energy electron collisions on insulating surfaces covered with various adsorbates. For such investigation a careful control of the sample surface potential is required to set the incident electron energy accurately as well as to identify the desorbed species by mass spectrometry. Most of the reported experiments concern this surface potential control. We show that, for very thin SiO2 films thermally grown on silicon substrates, a tunnel conduction might set the surface potential accurately. This assertion mainly relies on recording the intensity of electrons transmitted through thin oxides as well as the intensity of backscattered and secondary electrons re-emitted from the surface. A direct comparison of the O^- ion energy distributions confirms the correct control of the surface potential for a large range of incident electron energies. In such condition we noticed that the O^- desorption yields just swiftly varied with incident electron energy. In particular no modification could be detected as the incident electron energy passed the various Auger excitation levels. The discrepancy between this last result and the published data is discussed in the last part of this paper. Des collisions électroniques sur des surfaces peuvent provoquer une éjection d'ions négatifs formés à partir des molécules adsorbées suivant un processus résonnant à très basse énergie. Pour étendre ces études expérimentales aux surfaces isolantes, un contrôle précis du potentiel superficiel devient indispensable tant pour fixer l'énergie finale des électrons sur la surface que pour effectuer la spectrométrie des ions désorbés. L'examen de surfaces de silice en couche mince montre comment une conduction tunnel intervient pour fixer le potentiel des surfaces examinées. Ces travaux expérimentaux effectués dans une configuration de miroir électrostatique reposent principalement sur l

  13. Overriding follicle selection in controlled ovarian stimulation protocols: Quality vs quantity

    Directory of Open Access Journals (Sweden)

    Zelinski-Wooten Mary B

    2004-06-01

    Full Text Available Abstract Selection of the species-specific number of follicles that will develop and ovulate during the ovarian cycle can be overridden by increasing the levels of pituitary gonadotropin hormones, FSH and LH. During controlled ovarian stimulation (COS in nonhuman primates for assisted reproductive technology (ART protocols, the method of choice (but not the only method has been the administration of exogenous gonadotropins, either of nonprimate or primate origin. Due to species-specificity of the primate LH (but not FSH receptor, COS with nonprimate (e.g., PMSG hormones can be attributed to their FSH activity. Elevated levels of FSH alone will produce large antral follicles containing oocytes capable of fertilization in vitro (IVF. However, there is evidence that LH, probably in lesser amounts, increases the rate of follicular development, reduces heterogeneity of the antral follicle pool, and improves the viability and rate of pre-implantation development of IVF-produced embryos. Since an endogenous LH surge typically does not occur during COS cycles (especially when a GnRH antagonist is added, a large dose of an LH-like hormone (i.e., hCG may be given to reinitiate meiosis and produce fertilizable oocytes. Alternate approaches using exogenous LH (or FSH, or GnRH agonist to induce an endogenous LH surge, have received lesser attention. Current protocols will routinely yield dozens of large follicles with fertilizable eggs. However, limitations include non/poor-responding animals, heterogeneity of follicles (and presumably oocytes and subsequent short luteal phases (limiting embryo transfer in COS cycles. However, the most serious limitation to further improvements and expanded use of COS protocols for ART is the lack of availability of nonhuman primate gonadotropins. Human, and even more so, nonprimate gonadotropins are antigenic in monkeys, which limits the number of COS cycles to as few as 1 (PMSG or 3 (recombinant hCG protocols in macaques

  14. Brain-computer interface controlled functional electrical stimulation system for ankle movement.

    Science.gov (United States)

    Do, An H; Wang, Po T; King, Christine E; Abiri, Ahmad; Nenadic, Zoran

    2011-08-26

    Many neurological conditions, such as stroke, spinal cord injury, and traumatic brain injury, can cause chronic gait function impairment due to foot-drop. Current physiotherapy techniques provide only a limited degree of motor function recovery in these individuals, and therefore novel therapies are needed. Brain-computer interface (BCI) is a relatively novel technology with a potential to restore, substitute, or augment lost motor behaviors in patients with neurological injuries. Here, we describe the first successful integration of a noninvasive electroencephalogram (EEG)-based BCI with a noninvasive functional electrical stimulation (FES) system that enables the direct brain control of foot dorsiflexion in able-bodied individuals. A noninvasive EEG-based BCI system was integrated with a noninvasive FES system for foot dorsiflexion. Subjects underwent computer-cued epochs of repetitive foot dorsiflexion and idling while their EEG signals were recorded and stored for offline analysis. The analysis generated a prediction model that allowed EEG data to be analyzed and classified in real time during online BCI operation. The real-time online performance of the integrated BCI-FES system was tested in a group of five able-bodied subjects who used repetitive foot dorsiflexion to elicit BCI-FES mediated dorsiflexion of the contralateral foot. Five able-bodied subjects performed 10 alternations of idling and repetitive foot dorsifiexion to trigger BCI-FES mediated dorsifiexion of the contralateral foot. The epochs of BCI-FES mediated foot dorsifiexion were highly correlated with the epochs of voluntary foot dorsifiexion (correlation coefficient ranged between 0.59 and 0.77) with latencies ranging from 1.4 sec to 3.1 sec. In addition, all subjects achieved a 100% BCI-FES response (no omissions), and one subject had a single false alarm. This study suggests that the integration of a noninvasive BCI with a lower-extremity FES system is feasible. With additional modifications

  15. Brain-Computer Interface Controlled Functional Electrical Stimulation System for Ankle Movement

    Directory of Open Access Journals (Sweden)

    King Christine E

    2011-08-01

    Full Text Available Abstract Background Many neurological conditions, such as stroke, spinal cord injury, and traumatic brain injury, can cause chronic gait function impairment due to foot-drop. Current physiotherapy techniques provide only a limited degree of motor function recovery in these individuals, and therefore novel therapies are needed. Brain-computer interface (BCI is a relatively novel technology with a potential to restore, substitute, or augment lost motor behaviors in patients with neurological injuries. Here, we describe the first successful integration of a noninvasive electroencephalogram (EEG-based BCI with a noninvasive functional electrical stimulation (FES system that enables the direct brain control of foot dorsiflexion in able-bodied individuals. Methods A noninvasive EEG-based BCI system was integrated with a noninvasive FES system for foot dorsiflexion. Subjects underwent computer-cued epochs of repetitive foot dorsiflexion and idling while their EEG signals were recorded and stored for offline analysis. The analysis generated a prediction model that allowed EEG data to be analyzed and classified in real time during online BCI operation. The real-time online performance of the integrated BCI-FES system was tested in a group of five able-bodied subjects who used repetitive foot dorsiflexion to elicit BCI-FES mediated dorsiflexion of the contralateral foot. Results Five able-bodied subjects performed 10 alternations of idling and repetitive foot dorsifiexion to trigger BCI-FES mediated dorsifiexion of the contralateral foot. The epochs of BCI-FES mediated foot dorsifiexion were highly correlated with the epochs of voluntary foot dorsifiexion (correlation coefficient ranged between 0.59 and 0.77 with latencies ranging from 1.4 sec to 3.1 sec. In addition, all subjects achieved a 100% BCI-FES response (no omissions, and one subject had a single false alarm. Conclusions This study suggests that the integration of a noninvasive BCI with a lower

  16. Detection of RUNX2 gene expression in cumulus cells in women undergoing controlled ovarian stimulation

    Directory of Open Access Journals (Sweden)

    Papamentzelopoulou Myrto

    2012-11-01

    Full Text Available Abstract Background RUNX2 is a transcription factor, whose expression has been recently identified in the mouse ovary. Regulation of RUNX2 expression and its function in the human ovary have not been determined yet. The aim of the present study is the investigation of the possible correlation between RUNX2 gene expression in cumulus cells and controlled ovarian stimulation and pregnancy outcomes after ART treatment. Methods A total of 41 patients undergoing ICSI treatment for male factor infertility were enrolled into a specific ART program, during which cumulus cells were collected. The expression of RUNX2 gene in cumulus cells was examined by real-time PCR. Results Concerning RUNX2 gene expression, 12 out of 41 women were detected with RUNX2 expression, with ratios ranging from 0.84 to 1.00, while 28 out of 41 women had no expression (ratio = 0. Only 1 woman presented a weak RUNX2 gene expression (ratio = 0.52. From 8 women that proceeded to pregnancy, 7 of them did not express RUNX2 gene in cumulus cells, while one was the woman with weak gene expression that also achieved pregnancy. The group of women without RUNX2 expression presented higher number of follicles (p = 0.013, higher number of retrieved oocytes (p = 0.016, higher basal LH serum levels (p = 0.016 and higher peak estradiol levels (p = 0.013, while the number of fertilized oocytes differed marginally between the two groups (p = 0.089. Moreover, RUNX2 expression was negatively associated with LH levels (OR = 0.22, p = 0.021 and E2 levels (OR = 0.25, p = 0.026. Conclusions Consequently, based on the preliminary findings of the present pilot study a potential inhibitory mechanism of RUNX2 gene is observed in the ovary when high mRNA levels are detected, suggesting that RUNX2 could possibly be used as a candidate genetic marker in the monitoring of the outcome of an ART treatment.

  17. A fully on-chip three-terminal switched-capacitor DC-DC converter for low-voltage CMOS LSIs

    Science.gov (United States)

    Kojima, Yuta; Hirose, Tetsuya; Tsubaki, Keishi; Ozaki, Toshihiro; Asano, Hiroki; Kuroki, Nobutaka; Numa, Masahiro

    2016-04-01

    In this paper, we present a fully on-chip switched-capacitor DC-DC converter for low-voltage CMOS LSIs. The converter has three terminals of input, ground, and output, by developing control circuits with fully on-chip configuration. We employ an ultra low-power nanoampere bias current and voltage reference circuit to achieve ultra low-power dissipation of control circuits. It enables us to realize a highly efficient power conversion circuit at light-load-current applications. The converter achieves highly efficient and robust voltage conversion using a pulse frequency modulation control circuit and a start-up/fail-safe circuit. Measurement results demonstrated that the converter can convert a 3.0 V input into 1.2 V output successfully. The start-up and fail-safe operations were confirmed through the measurement. The efficiency was more than 50% in the range of 2-6 µA load current.

  18. Frequent Nonprescription Stimulant Use and Risky Behaviors in College Students: The Role of Effortful Control

    Science.gov (United States)

    Reid, Adam M.; Graziano, Paulo A.; Balkhi, Amanda M.; McNamara, Joseph P. H.; Cottler, Linda B.; Meneses, Evander; Geffken, Gary R.

    2015-01-01

    Objective: The goal of this study was to (a) investigate the association between nonprescription stimulant use (NPSU) and risky behaviors, including risky sex, driving, financial behaviors, and drug use and (b) collect preliminary evidence on mechanisms that may link NPSU to risky behaviors. Participants: A sample of 555 college students was…

  19. Peripheral electrical stimulation in Alzheimer's disease - A randomized controlled trial on cognition and behavior

    NARCIS (Netherlands)

    van Dijk, Koene R.A.; Scheltens, Philip; Luijpen, Marijn W.; Sergeant, Joseph A.; Scherder, Erik J.A.

    2005-01-01

    In a number of studies, peripheral electrical nerve stimulation has been applied to Alzheimer's disease (AD) patients who lived in a nursing home. Improvements were observed in memory, verbal fluency, affective behavior, activities of daily living and on the rest-activity rhythm and pupillary light

  20. Habituation to experimentally induced electrical pain during voluntary-breathing controlled electrical stimulation (BreEStim.

    Directory of Open Access Journals (Sweden)

    Shengai Li

    Full Text Available OBJECTIVE: Painful peripheral electrical stimulation to acupuncture points was found to cause sensitization if delivered randomly (EStim, but induced habituation if triggered by voluntary breathing (BreEStim. The objective was to systematically compare the effectiveness of BreEStim and EStim and to investigate the possible mechanisms mediating the habituation effect of BreEStim. METHODS: Eleven pain-free, healthy subjects (6 males, 5 females participated in the study. Each subject received the BreEStim and EStim treatments in a random order at least three days apart. Both treatments consisted of 120 painful but tolerable stimuli to the ulnar nerve at the elbow on the dominant arm. BreEStim was triggered by voluntary breathing while EStim was delivered randomly. Electrical sensation threshold (EST and electrical pain threshold (EPT were measured from the thenar and hypothenar eminences on both hands at pre-intervention and 10-minutes post-intervention. RESULTS: There was no difference in the pre-intervention baseline measurement of EST and EPT between BreEStim and EStim. BreEStim increased EPT in all tested sites on both hands, while EStim increased EPT in the dominant hypothenar eminence distal to the stimulating site and had no effect on EPT in other sites. There was no difference in the intensity of electrical stimulation between EStim and BreEStim. CONCLUSION: Our findings support the important role human voluntary breathing plays in the systemic habituation effect of BreEStim to peripheral painful electrical stimulation.

  1. Transcranial direct current stimulation in refractory continuous spikes and waves during slow sleep: a controlled study

    DEFF Research Database (Denmark)

    Varga, Edina T; Terney, Daniella; Atkins, Mary D

    2011-01-01

    Cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability. The purpose of the study was to investigate whether cathodal tDCS could interrupt the continuous epileptiform activity. Five patients with focal, refractory continuous spikes and waves during slow sleep were ...

  2. Sensing and stimulation of the vagus nerve for artificial cardiac control

    NARCIS (Netherlands)

    Ordelman, Simone Cornelia Maria Anna

    2012-01-01

    This thesis focuses on sensing cardiovascular signals from the vagus nerve and electrically stimulating the vagus nerve for cardiovascular effects. Sensing cardiovascular signals was attempted on both spontaneous and evoked neural activity. A cardiac-modulated vagus nerve activity pattern was found

  3. Prenatal Cigarette Exposure and Infant Learning Stimulation as Predictors of Cognitive Control in Childhood

    Science.gov (United States)

    Mezzacappa, Enrico; Buckner, John C.; Earls, Felton

    2011-01-01

    Prenatal exposures to neurotoxins and postnatal parenting practices have been shown to independently predict variations in the cognitive development and emotional-behavioral well-being of infants and children. We examined the independent contributions of prenatal cigarette exposure and infant learning stimulation, as well as their…

  4. Peripheral electrical stimulation in Alzheimer's disease - A randomized controlled trial on cognition and behavior

    NARCIS (Netherlands)

    van Dijk, KRA; Scheltens, P; Luijpen, MW; Sergeant, JA; Scherder, EJA

    2005-01-01

    In a number of studies, peripheral electrical nerve stimulation has been applied to Alzheimer's disease (AD) patients who lived in a nursing home. Improvements were observed in memory, verbal fluency, affective behavior, activities of daily living and on the rest-activity rhythm and pupillary light

  5. Prenatal Cigarette Exposure and Infant Learning Stimulation as Predictors of Cognitive Control in Childhood

    Science.gov (United States)

    Mezzacappa, Enrico; Buckner, John C.; Earls, Felton

    2011-01-01

    Prenatal exposures to neurotoxins and postnatal parenting practices have been shown to independently predict variations in the cognitive development and emotional-behavioral well-being of infants and children. We examined the independent contributions of prenatal cigarette exposure and infant learning stimulation, as well as their…

  6. Stimulant Reduction Intervention using Dosed Exercise (STRIDE - CTN 0037: Study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Morris David W

    2011-09-01

    Full Text Available Abstract Background There is a need for novel approaches to the treatment of stimulant abuse and dependence. Clinical data examining the use of exercise as a treatment for the abuse of nicotine, alcohol, and other substances suggest that exercise may be a beneficial treatment for stimulant abuse, with direct effects on decreased use and craving. In addition, exercise has the potential to improve other health domains that may be adversely affected by stimulant use or its treatment, such as sleep disturbance, cognitive function, mood, weight gain, quality of life, and anhedonia, since it has been shown to improve many of these domains in a number of other clinical disorders. Furthermore, neurobiological evidence provides plausible mechanisms by which exercise could positively affect treatment outcomes. The current manuscript presents the rationale, design considerations, and study design of the National Institute on Drug Abuse (NIDA Clinical Trials Network (CTN CTN-0037 Stimulant Reduction Intervention using Dosed Exercise (STRIDE study. Methods/Design STRIDE is a multisite randomized clinical trial that compares exercise to health education as potential treatments for stimulant abuse or dependence. This study will evaluate individuals diagnosed with stimulant abuse or dependence who are receiving treatment in a residential setting. Three hundred and thirty eligible and interested participants who provide informed consent will be randomized to one of two treatment arms: Vigorous Intensity High Dose Exercise Augmentation (DEI or Health Education Intervention Augmentation (HEI. Both groups will receive TAU (i.e., usual care. The treatment arms are structured such that the quantity of visits is similar to allow for equivalent contact between groups. In both arms, participants will begin with supervised sessions 3 times per week during the 12-week acute phase of the study. Supervised sessions will be conducted as one-on-one (i.e., individual sessions

  7. Stimulation of the autonomic nervous system in colorectal surgery: a study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Berghmans Tim MP

    2012-06-01

    Full Text Available Abstract Background Postoperative ileus (POI is a well-known complication of abdominal surgery and is considered to be caused by a local inflammation in the gut. Previously it has been shown that both local and systemic inflammation can be reduced by stimulation of the autonomic nervous system via lipid rich nutrition. Stimulation of the autonomic nervous system releases acetylcholine from efferent vagal nerve endings that binds to nicotinic receptors located on the inflammatory cells leading to a decrease of pro-inflammatory mediators. Besides administration of nutrition there are other ways of stimulating the autonomic nervous system such as gum chewing. Methods/design This prospective, placebo-controlled randomized trial will include 120 patients undergoing colorectal surgery which are randomized for gum chewing preoperatively and in the direct postoperative phase or a placebo. Postoperative ileus will be assessed both clinically by time to first flatus and time to first defecation and by determination of gastric motility using ultrasound to measure dimensions of the antrum. Furthermore the inflammatory response is quantified by analyzing pro-inflammatory mediators. Finally, markers of gut barrier integrity will be measured as well as occurrence of postoperative complications. Discussion We hypothesize that chewing gum preoperatively and in the direct postoperative phase in patients undergoing colorectal surgery dampens local and systematic inflammation, via activation of the autonomic nervous system. Down-regulation of the inflammatory cascade via stimulation of the vagus nerve will ameleriote POI and enhance postoperative recovery. Trial registration NTR2867

  8. On-chip dual comb source for spectroscopy

    CERN Document Server

    Dutt, Avik; Ji, Xingchen; Cardenas, Jaime; Okawachi, Yoshitomo; Luke, Kevin; Gaeta, Alexander L; Lipson, Michal

    2016-01-01

    Dual-comb spectroscopy is a powerful technique for real-time, broadband optical sampling of molecular spectra which requires no moving components. Recent developments with microresonator-based platforms have enabled frequency combs at the chip scale. However, the need to precisely match the resonance wavelengths of distinct high-quality-factor microcavities has hindered the development of an on-chip dual comb source. Here, we report the first simultaneous generation of two microresonator combs on the same chip from a single laser. The combs span a broad bandwidth of 51 THz around a wavelength of 1.56 $\\mu$m. We demonstrate low-noise operation of both frequency combs by deterministically tuning into soliton mode-locked states using integrated microheaters, resulting in narrow ($<$ 10 kHz) microwave beatnotes. We further use one mode-locked comb as a reference to probe the formation dynamics of the other comb, thus introducing a technique to investigate comb evolution without auxiliary lasers or microwave os...

  9. Multimedia Terminal System-on-Chip Design and Simulation

    Directory of Open Access Journals (Sweden)

    Barbieri Ivano

    2005-01-01

    Full Text Available This paper proposes a design approach based on integrated architectural and system-on-chip (SoC simulations. The main idea is to have an efficient framework for the design and the evaluation of multimedia terminals, allowing a fast system simulation with a definable degree of accuracy. The design approach includes the simulation of very long instruction word (VLIW digital signal processors (DSPs, the utilization of a device multiplexing the media streams, and the emulation of the real-time media acquisition. This methodology allows the evaluation of both the multimedia algorithm implementations and the hardware platform, giving feedback on the complete SoC including the interaction between modules and conflicts in accessing either the bus or shared resources. An instruction set architecture (ISA simulator and an SoC simulation environment compose the integrated framework. In order to validate this approach, the evaluation of an audio-video multiprocessor terminal is presented, and the complete simulation test results are reported.

  10. Micromechanical Characterization of Polysilicon Films through On-Chip Tests

    Directory of Open Access Journals (Sweden)

    Ramin Mirzazadeh

    2016-07-01

    Full Text Available When the dimensions of polycrystalline structures become comparable to the average grain size, some reliability issues can be reported for the moving parts of inertial microelectromechanical systems (MEMS. Not only the overall behavior of the device turns out to be affected by a large scattering, but also the sensitivity to imperfections gets enhanced. In this work, through on-chip tests, we experimentally investigate the behavior of thin polysilicon samples using standard electrostatic actuation/sensing. The discrepancy between the target and actual responses of each sample has then been exploited to identify: (i the overall stiffness of the film and, according to standard continuum elasticity, a morphology-based value of its Young’s modulus; (ii the relevant over-etch induced by the fabrication process. To properly account for the aforementioned stochastic features at the micro-scale, the identification procedure has been based on particle filtering. A simple analytical reduced-order model of the moving structure has been also developed to account for the nonlinearities in the electrical field, up to pull-in. Results are reported for a set of ten film samples of constant slenderness, and the effects of different actuation mechanisms on the identified micromechanical features are thoroughly discussed.

  11. Pipelined multiprocessor system-on-chip for multimedia

    CERN Document Server

    Javaid, Haris

    2014-01-01

    This book describes analytical models and estimation methods to enhance performance estimation of pipelined multiprocessor systems-on-chip (MPSoCs).  A framework is introduced for both design-time and run-time optimizations. For design space exploration, several algorithms are presented to minimize the area footprint of a pipelined MPSoC under a latency or a throughput constraint.  A novel adaptive pipelined MPSoC architecture is described, where idle processors are transitioned into low-power states at run-time to reduce energy consumption. Multi-mode pipelined MPSoCs are introduced, where multiple pipelined MPSoCs optimized separately are merged into a single pipelined MPSoC, enabling further reduction of the area footprint by sharing the processors and communication buffers. Readers will benefit from the authors’ combined use of analytical models, estimation methods and exploration algorithms and will be enabled to explore billions of design points in a few minutes.   ·         Describes the ...

  12. Micromechanical Characterization of Polysilicon Films through On-Chip Tests.

    Science.gov (United States)

    Mirzazadeh, Ramin; Eftekhar Azam, Saeed; Mariani, Stefano

    2016-07-28

    When the dimensions of polycrystalline structures become comparable to the average grain size, some reliability issues can be reported for the moving parts of inertial microelectromechanical systems (MEMS). Not only the overall behavior of the device turns out to be affected by a large scattering, but also the sensitivity to imperfections gets enhanced. In this work, through on-chip tests, we experimentally investigate the behavior of thin polysilicon samples using standard electrostatic actuation/sensing. The discrepancy between the target and actual responses of each sample has then been exploited to identify: (i) the overall stiffness of the film and, according to standard continuum elasticity, a morphology-based value of its Young's modulus; (ii) the relevant over-etch induced by the fabrication process. To properly account for the aforementioned stochastic features at the micro-scale, the identification procedure has been based on particle filtering. A simple analytical reduced-order model of the moving structure has been also developed to account for the nonlinearities in the electrical field, up to pull-in. Results are reported for a set of ten film samples of constant slenderness, and the effects of different actuation mechanisms on the identified micromechanical features are thoroughly discussed.

  13. Ultrasensitive interferometric on-chip microscopy of transparent objects

    Science.gov (United States)

    Terborg, Roland A.; Pello, Josselin; Mannelli, Ilaria; Torres, Juan P.; Pruneri, Valerio

    2016-01-01

    Light microscopes can detect objects through several physical processes, such as scattering, absorption, and reflection. In transparent objects, these mechanisms are often too weak, and interference effects are more suitable to observe the tiny refractive index variations that produce phase shifts. We propose an on-chip microscope design that exploits birefringence in an unconventional geometry. It makes use of two sheared and quasi-overlapped illuminating beams experiencing relative phase shifts when going through the object, and a complementary metal-oxide-semiconductor image sensor array to record the resulting interference pattern. Unlike conventional microscopes, the beams are unfocused, leading to a very large field of view (20 mm2) and detection volume (more than 0.5 cm3), at the expense of lateral resolution. The high axial sensitivity (<1 nm) achieved using a novel phase-shifting interferometric operation makes the proposed device ideal for examining transparent substrates and reading microarrays of biomarkers. This is demonstrated by detecting nanometer-thick surface modulations on glass and single and double protein layers. PMID:27386571

  14. Light interference detection on-chip by integrated SNSPD counters

    Directory of Open Access Journals (Sweden)

    Paul Cavalier

    2011-12-01

    Full Text Available A SWIFTS device (Stationary Wave Integrated Fourier Transform Spectrometer has been realized with an array of 24 Superconducting Nanowire Single Photon Detectors (SNSPD, on-chip integrated under a Si3N4 monomode rib-waveguide interferometer. Colored light around 1.55μm wavelength is introduced through end-fire coupling, producing a counter-propagative stationary interferogram over the 40nm wide, 120nm spaced, 4nm thick epi-NbN nanowire array. Modulations in the source bandwidth have been detected using individual waveguide coupled SNSPDs operating in single photon counting mode, which is a step towards light spectrum reconstruction by inverse Fourier transform of the stationary wave intensity. We report the design, fabrication process and in-situ measurement at 4.2K of light power modulation in the interferometer, obtained with variable laser wavelength. Such micro-SWIFTS configuration with 160nm sampling period over 3.84μm distance allows a spectral bandwidth of 2μm and a wavelength resolution of 170nm. The light interferences direct sampling ability is unique and raises wide interest with several potential applications like fringe-tracking, metrology, cryptography or optical tomography.

  15. Age-related deficits in voluntary control over saccadic eye movements: consideration of electrical brain stimulation as a therapeutic strategy.

    Science.gov (United States)

    Chen, Po Ling; Machado, Liana

    2016-05-01

    Sudden changes in our visual environment trigger reflexive eye movements, so automatically they often go unnoticed. Consequently, voluntary control over reflexive eye movements entails considerable effort. In relation to frontal-lobe deterioration, adult aging adversely impacts voluntary saccadic eye movement control in particular, which compromises effective performance of daily activities. Here, we review the nature of age-related changes in saccadic control, focusing primarily on the antisaccade task because of its assessment of 2 key age-sensitive control functions: reflexive saccade inhibition and voluntary saccade generation. With an ultimate view toward facilitating development of therapeutic strategies, we systematically review the neuroanatomy underpinning voluntary control over saccadic eye movements and natural mechanisms that kick in to compensate for age-related declines. We then explore the potential of noninvasive electrical brain stimulation to counteract aging deficits. Based on evidence that anodal transcranial direct current stimulation can confer a range of benefits specifically relevant to aging brains, we put forward this neuromodulation technique as a therapeutic strategy for improving voluntary saccadic eye movement control in older adults. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Myoelectrically driven functional electrical stimulation may increase motor recovery of upper limb in poststroke subjects: A randomized controlled pilot study

    Directory of Open Access Journals (Sweden)

    Rune Thorsen, PhD, MScee

    2013-08-01

    Full Text Available The objective of this randomized controlled pilot study was to assess the feasibility and effectiveness of myoelectrically controlled functional electrical stimulation (MeCFES for rehabilitation of the upper limb in poststroke subjects. Eleven poststroke hemiparetic subjects with residual proximal control of the arm, but impaired volitional opening of the paretic hand, were enrolled and randomized into a treated and a control group. Subjects received 3 to 5 treatment sessions per week until totaling 25 sessions. In the experimental group, myoelectric activity from wrist and finger extensors was used to control stimulation of the same muscles. Patients treated with MeCFES (n = 5 had a significant (p = 0.04 and clinically important improvement in Action Research Arm Test score (median change 9 points, confirmed by an Individually Prioritized Problem Assessment self-evaluation score. This improvement was maintained at follow-up. The control group did not show a significant improvement (p = 0.13. The reduced sample size of participants, together with confounding factors such as spontaneous recovery, calls for larger studies to draw definite conclusions. However, the large and persistent treatment effect seen in our results indicate that MeCFES could play an important role as a clinical tool for stroke rehabilitation.

  17. Hybrid neuroprosthesis for the upper limb: combining brain-controlled neuromuscular stimulation with a multi-joint arm exoskeleton

    Directory of Open Access Journals (Sweden)

    Florian Grimm

    2016-08-01

    Full Text Available Brain-machine interface-controlled (BMI neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related range of motion and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. Neuromuscular electrical stimulation was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD and electromyography (EMG activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e. induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p=0.028 or EMG (p=0.021 modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related range of motion (p=0.009 and the movement-related brain modulation (p=0

  18. Contribution of SK and BK channels in the control of catecholamine release by electrical stimulation of the cat adrenal gland.

    Science.gov (United States)

    Montiel, C; López, M G; Sánchez-García, P; Maroto, R; Zapater, P; García, A G

    1995-07-15

    on catecholamine release induced by electrical stimulation was observed at low but not at high [Ca2+]o. 6. Simultaneous release of acetylcholine and catecholamines upon electrical stimulation was achieved in glands in which the endogenous acetylcholine stores in the splanchnic nerve terminals had been prelabelled by perfusion with [3H]choline. While apamin enhanced more than 2-fold the postsynaptic release of catecholamines, the presynaptic release of acetylcholine remained unaffected. 7. The results are compatible with the hypothesis that, under physiological conditions, Ca(2+)-activated SK channels present in chromaffin cells control the firing patterns of action potentials induced by the acetylcholine released from splanchnic nerves during stress.(ABSTRACT TRUNCATED AT 400 WORDS)

  19. Contribution of SK and BK channels in the control of catecholamine release by electrical stimulation of the cat adrenal gland.

    Science.gov (United States)

    Montiel, C; López, M G; Sánchez-García, P; Maroto, R; Zapater, P; García, A G

    1995-01-01

    on catecholamine release induced by electrical stimulation was observed at low but not at high [Ca2+]o. 6. Simultaneous release of acetylcholine and catecholamines upon electrical stimulation was achieved in glands in which the endogenous acetylcholine stores in the splanchnic nerve terminals had been prelabelled by perfusion with [3H]choline. While apamin enhanced more than 2-fold the postsynaptic release of catecholamines, the presynaptic release of acetylcholine remained unaffected. 7. The results are compatible with the hypothesis that, under physiological conditions, Ca(2+)-activated SK channels present in chromaffin cells control the firing patterns of action potentials induced by the acetylcholine released from splanchnic nerves during stress.(ABSTRACT TRUNCATED AT 400 WORDS) Images Figure 3 Figure 4 Figure 6 PMID:7473208

  20. A Quality-of-Service Mechanism for Interconnection Networks in System-on-Chips

    CERN Document Server

    Weber, Wolf-Dietrich; Swarbrick, Ian; Wingard, Drew

    2011-01-01

    As Moore's Law continues to fuel the ability to build ever increasingly complex system-on-chips (SoCs), achieving performance goals is rising as a critical challenge to completing designs. In particular, the system interconnect must efficiently service a diverse set of data flows with widely ranging quality-of-service (QoS) requirements. However, the known solutions for off-chip interconnects such as large-scale networks are not necessarily applicable to the on-chip environment. Latency and memory constraints for on-chip interconnects are quite different from larger-scale interconnects. This paper introduces a novel on-chip interconnect arbitration scheme. We show how this scheme can be distributed across a chip for high-speed implementation. We compare the performance of the arbitration scheme with other known interconnect arbitration schemes. Existing schemes typically focus heavily on either low latency of service for some initiators, or alternatively on guaranteed bandwidth delivery for other initiators. ...

  1. Femtosecond laser fabrication for the integration of optical sensors in microfluidic lab-on-chip devices

    NARCIS (Netherlands)

    Osellame, R.; Martinez-Vazquez, R.; Dongre, C.; Dekker, R.; Hoekstra, H.J.W.M.; Ramponi, R.; Pollnau, M.; Cerullo, G.; Corkum, P.; Silvestri, de S.; Nelson, K.A.; Riedle, E.; Schoenlein, R.W.

    2009-01-01

    Femtosecond lasers enable the fabrication of both optical waveguides and buried microfluidic channels on a glass substrate. The waveguides are used to integrate optical detection in a commercial microfluidic lab-on-chip for capillary electrophoresis.

  2. Femtosecond laser fabrication for the integration of optical sensors in microfluidic lab-on-chip devices

    NARCIS (Netherlands)

    Osellame, R.; Martinez Vazquez, R.; Dongre, C.; Dekker, R.; Hoekstra, H.J.W.M.; Pollnau, M.; Ramponi, R.; Cerullo, G.

    2008-01-01

    Femtosecond lasers enable the fabrication of both optical waveguides and buried microfluidic channels on a glass substrate. The waveguides are used to integrate optical detection in a commercial microfluidic lab-on-chip for capillary electrophoresis

  3. Implementation of Guaranteed Services in the MANGO Clockless Network-on-Chip

    DEFF Research Database (Denmark)

    Bjerregaard, Tobias; Sparsø, Jens

    2006-01-01

    the effects of scaling microchip technologies. Equally important, a NoC facilitates a truly modular and scalable design flow. The MANGO (message-passing asynchronous network-on-chip providing guaranteed services over open core protocol (OCP) interfaces) NoC is presented, and how its key characteristics......Shared, segmented, on-chip interconnection networks, known as networks-on-chip (NoC), may become the preferred way of interconnecting intellectual property (IP) cores in future giga-scale system-on-chip (SoC) designs. A NoC can provide the required communication bandwidth while accommodating...... (clockless implementation, standard socket access points, and guaranteed communication services) make MANGO suitable for a modular SoC design flow is explained. Among the advantages of using clockless circuit techniques are inherent global timing closure, low forward latency in pipelines, and zero dynamic...

  4. On-Chip Micro-Electro-Mechanical System Fourier Transform Infrared (MEMS FT-IR) Spectrometer-Based Gas Sensing.

    Science.gov (United States)

    Erfan, Mazen; Sabry, Yasser M; Sakr, Mohammad; Mortada, Bassem; Medhat, Mostafa; Khalil, Diaa

    2016-05-01

    In this work, we study the detection of acetylene (C2H2), carbon dioxide (CO2) and water vapor (H2O) gases in the near-infrared (NIR) range using an on-chip silicon micro-electro-mechanical system (MEMS) Fourier transform infrared (FT-IR) spectrometer in the wavelength range 1300-2500 nm (4000-7692 cm(-1)). The spectrometer core engine is a scanning Michelson interferometer micro-fabricated using a deep-etching technology producing self-aligned components. The light is free-space propagating in-plane with respect to the silicon chip substrate. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator corresponding to about 30 cm(-1) resolution. Multi-mode optical fibers are used to connect light between the wideband light source, the interferometer, the 10 cm gas cell, and the optical detector. A wide dynamic range of gas concentration down to 2000 parts per million (ppm) in only 10 cm length gas cell is demonstrated. Extending the wavelength range to the mid-infrared (MIR) range up to 4200 nm (2380 cm(-1)) is also experimentally demonstrated, for the first time, using a bulk micro-machined on-chip MEMS FT-IR spectrometer. The obtained results open the door for an on-chip optical gas sensor for many applications including environmental sensing and industrial process control in the NIR/MIR spectral ranges.

  5. Effects of Repetitive Transcranial Magnetic Stimulation in the Rehabilitation of Communication and Deglutition Disorders: Systematic Review of Randomized Controlled Trials.

    Science.gov (United States)

    Gadenz, Camila Dalbosco; Moreira, Tais de Campos; Capobianco, Dirce Maria; Cassol, Mauriceia

    2015-01-01

    To systematically review randomized controlled trials that evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on rehabilitation aspects related to communication and swallowing functions. A search was conducted on PubMed, Clinical Trials, Cochrane Library, and ASHA electronic databases. Studies were judged according to the eligibility criteria and analyzed by 2 independent and blinded researchers. We analyzed 9 studies: 4 about aphasia, 3 about dysphagia, 1 about dysarthria in Parkinson's disease and 1 about linguistic deficits in Alzheimer's disease. All aphasia studies used low-frequency rTMS to stimulate Broca's homologous area. High-frequency rTMS was applied over the pharyngoesophageal cortex from the left and/or right hemisphere in the dysphagia studies and over the left dorsolateral prefrontal cortex in the Parkinson's and Alzheimer's studies. Two aphasia and all dysphagia studies showed a significant improvement of the disorder, compared to the sham group. The other 2 studies related to aphasia found a benefit restricted to subgroups with a severe case or injury on the anterior portion of the language cortical area, respectively, whereas the Alzheimer's study demonstrated positive effects specific to auditory comprehension. There were no changes for vocal function in the Parkinson's study. The benefits of the technique and its applicability in neurogenic disorders related to communication and deglutition are still uncertain. Therefore, other randomized controlled trials are needed to clarify the optimal stimulation protocol for each disorder studied and its real effects. © 2015 S. Karger AG, Basel.

  6. Improved ankle and knee control with a dual-channel functional electrical stimulation system in chronic hemiplegia. A case report.

    Science.gov (United States)

    Springer, S; Khamis, S; Laufer, Y

    2014-04-01

    The aim of tis report is to describe the effects of a dual-channel functional electrical stimulation (FES) system applied daily as an orthotic device to the dorsiflexors and hamstrings muscles in a subject with chronic hemiparesis. Prior to the application of FES, the patient's gait was characterized by a footdrop and knee hyperextension during stance. measurements of gait performance were collected before FES application, after a conditioning period of six weeks, and following ten months of daily use. Outcomes included lower limb kinematics and temporal gait measures. The kinematic assessments indicated significant benefits for gait with the dorsiflexors and hamstrings FES, as compared to no stimulation and peroneal FES alone. In addition ot improved ankle control, knee hyperextension was reduced during stance, and the self-selected comfortable gait velocity increased following ten months of daily use. The results of this report suggest that dual-channel FES for the dorsiflexors and hamstrings muscles may affect ankle and knee control beyond that witch can be attributed to peroneal stimulation alone. The positive effects observed in this case study point to the potential of dual-channel FES as a viable treatment options in the rehabilitation of patients with similar impairments.

  7. Real-time and wearable functional electrical stimulation system for volitional hand motor function control using the electromyography bridge method.

    Science.gov (United States)

    Wang, Hai-Peng; Bi, Zheng-Yang; Zhou, Yang; Zhou, Yu-Xuan; Wang, Zhi-Gong; Lv, Xiao-Ying

    2017-01-01

    Voluntary participation of hemiplegic patients is crucial for functional electrical stimulation therapy. A wearable functional electrical stimulation system has been proposed for real-time volitional hand motor function control using the electromyography bridge method. Through a series of novel design concepts, including the integration of a detecting circuit and an analog-to-digital converter, a miniaturized functional electrical stimulation circuit technique, a low-power super-regeneration chip for wireless receiving, and two wearable armbands, a prototype system has been established with reduced size, power, and overall cost. Based on wrist joint torque reproduction and classification experiments performed on six healthy subjects, the optimized surface electromyography thresholds and trained logistic regression classifier parameters were statistically chosen to establish wrist and hand motion control with high accuracy. Test results showed that wrist flexion/extension, hand grasp, and finger extension could be reproduced with high accuracy and low latency. This system can build a bridge of information transmission between healthy limbs and paralyzed limbs, effectively improve voluntary participation of hemiplegic patients, and elevate efficiency of rehabilitation training.

  8. Accelerated intermittent Theta Burst stimulation for suicide risk in therapy-resistant depressed patients: a randomized, sham-controlled trial.

    Directory of Open Access Journals (Sweden)

    Stefanie Desmyter

    2016-09-01

    Full Text Available Objectives We aimed to examine the effects and safety of accelerated intermittent Theta Burst Stimulation (iTBS on suicide risk in a group of treatment-resistant unipolar depressed patients, using an extensive suicide assessment scale. Methods In 50 therapy-resistant, antidepressant-free depressed patients, an intensive protocol of accelerated iTBS was applied over the left dorsolateral prefrontal cortex in a randomized, sham-controlled cross-over design. Patients received 20 iTBS sessions over 4 days. Suicide risk was assessed using the Beck Scale of Suicide ideation (BSI. Results The iTBS protocol was safe and well-tolerated. We observed a significant decrease of the BSI score over time, unrelated to active or sham stimulation and unrelated to depression-response. No worsening of suicidal ideation was observed. The effects of accelerated iTBS on mood and depression severity are reported in Duprat et al. (2016. The decrease in suicide risk lasted up to one month after baseline, even in depression non-responders. Conclusions This accelerated iTBS protocol was safe. The observed significant decrease in suicide risk was unrelated to active or sham stimulation and unrelated to depression response. Further sham-controlled research in suicidal depressed patients is necessary.(clinicaltrials.gov identifier: NCT01832805

  9. Real-time and wearable functional electrical stimulation system for volitional hand motor function control using the electromyography bridge method

    Directory of Open Access Journals (Sweden)

    Hai-peng Wang

    2017-01-01

    Full Text Available Voluntary participation of hemiplegic patients is crucial for functional electrical stimulation therapy. A wearable functional electrical stimulation system has been proposed for real-time volitional hand motor function control using the electromyography bridge method. Through a series of novel design concepts, including the integration of a detecting circuit and an analog-to-digital converter, a miniaturized functional electrical stimulation circuit technique, a low-power super-regeneration chip for wireless receiving, and two wearable armbands, a prototype system has been established with reduced size, power, and overall cost. Based on wrist joint torque reproduction and classification experiments performed on six healthy subjects, the optimized surface electromyography thresholds and trained logistic regression classifier parameters were statistically chosen to establish wrist and hand motion control with high accuracy. Test results showed that wrist flexion/extension, hand grasp, and finger extension could be reproduced with high accuracy and low latency. This system can build a bridge of information transmission between healthy limbs and paralyzed limbs, effectively improve voluntary participation of hemiplegic patients, and elevate efficiency of rehabilitation training.

  10. Assessment of mitochondrial membrane potential using an on-chip microelectrode in a microfluidic device.

    Science.gov (United States)

    Lim, Tae-Sun; Dávila, Antonio; Wallace, Douglas C; Burke, Peter

    2010-07-07

    The mitochondrial membrane potential is used to generate and regulate energy in living systems, driving the conversion of ADP to ATP, regulating ion homeostasis, and controlling apoptosis, all central to human health and disease. Therefore, there is a need for tools to study its regulation in a controlled environment for potential clinical and scientific applications. For this aim, an on-chip tetraphenylphosphonium (TPP(+)) selective microelectrode sensor was constructed in a microfluidic environment. The concentration of isolated mitochondria (Heb7A) used in a membrane potential measurement was 0.3 ng microL(-1), four orders of magnitude smaller than the concentration used in conventional assays (3 microg microL(-1)). In addition, the volume of the chamber (85 microL) is 2 orders of magnitude smaller than traditional experiments. As a demonstration, changes in the membrane potential are clearly measured in response to a barrage of well-known substrates and inhibitors of the electron transport chain. This general approach, which to date has not been demonstrated for study of mitochondrial function and bio-energetics in generally, can be instrumental in advancing the field of mitochondrial research and clinical applications by allowing high throughput studies of the regulation, dynamics, and statistical properties of the mitochondrial membrane potential in response to inhibitors and inducers of apoptosis in a controlled (microfluidic) chemical environment.

  11. Nomogram to predict the number of oocytes retrieved in controlled ovarian stimulation.

    Science.gov (United States)

    Moon, Kyoung Yong; Kim, Hoon; Lee, Joong Yeup; Lee, Jung Ryeol; Jee, Byung Chul; Suh, Chang Suk; Kim, Ki Chul; Lee, Won Don; Lim, Jin Ho; Kim, Seok Hyun

    2016-06-01

    Ovarian reserve tests are commonly used to predict ovarian response in infertile patients undergoing ovarian stimulation. Although serum markers such as basal follicle-stimulating hormone (FSH) or random anti-Müllerian hormone (AMH) level and ultrasonographic markers (antral follicle count, AFC) are good predictors, no single test has proven to be the best predictor. In this study, we developed appropriate equations and novel nomograms to predict the number of oocytes that will be retrieved using patients' age, serum levels of basal FSH and AMH, and AFC. We analyzed a database containing clinical and laboratory information of 141 stimulated in vitro fertilization (IVF) cycles performed at a university-based hospital between September 2009 and December 2013. We used generalized linear models for prediction of the number of oocytes. Age, basal serum FSH level, serum AMH level, and AFC were significantly related to the number of oocytes retrieved according to the univariate and multivariate analyses. The equations that predicted the number of oocytes retrieved (log scale) were as follows: model (1) 3.21-0.036×(age)+0.089×(AMH), model (2) 3.422-0.03×(age)-0.049×(FSH)+0.08×(AMH), model (3) 2.32-0.017×(age)+0.039×(AMH)+0. 03×(AFC), model (4) 2.584-0.015×(age)-0.035×(FSH)+0.038×(AMH)+0.026×(AFC). model 4 showed the best performance. On the basis of these variables, we developed nomograms to predict the number of oocytes that can be retrieved. Our nomograms helped predict the number of oocytes retrieved in stimulated IVF cycles.

  12. Photonic-Networks-on-Chip for High Performance Radiation Survivable Multi-Core Processor Systems

    Science.gov (United States)

    2013-12-01

    TR-14-7 Photonic-Networks-on-Chip for High Performance Radiation Survivable Multi-Core Processor Systems Approved for public release...Networks-on-Chip for High Performance Radiation Survivable Multi-Core Processor Systems DTRA01-03-D-0026 Prof. Luke Lester and Prof. Ganesh...release; distribution is unlimited. The University of New Mexico has undertaken a study to determine the effects of radiation on Quantum Dot Photonic

  13. A survey of research and practices of network-on-chip

    DEFF Research Database (Denmark)

    Bjerregaard, Tobias; Mahadevan, Shankar

    2006-01-01

    The scaling of microchip technologies has enabled large scale systems-on-chip (SoC). Network-on-chip (NoC) research addresses global communication in SoC, involving (i) a move from computation-centric to communication-centric design and (ii) the implementation of scalable communication structures...... are discussed. We also evaluate performance analysis techniques. The research shows that NoC constitutes a unification of current trends of intrachip communication rather than an explicit new alternative....

  14. G domain dimerization controls dynamin's assembly-stimulated GTPase activity

    Energy Technology Data Exchange (ETDEWEB)

    Chappie, Joshua S.; Acharya, Sharmistha; Leonard, Marilyn; Schmid, Sandra L.; Dyda, Fred (NIH); (Scripps)

    2010-06-14

    Dynamin is an atypical GTPase that catalyses membrane fission during clathrin-mediated endocytosis. The mechanisms of dynamin's basal and assembly-stimulated GTP hydrolysis are unknown, though both are indirectly influenced by the GTPase effector domain (GED). Here we present the 2.0 {angstrom} resolution crystal structure of a human dynamin 1-derived minimal GTPase-GED fusion protein, which was dimeric in the presence of the transition state mimic GDP.AlF{sub 4}{sup -}. The structure reveals dynamin's catalytic machinery and explains how assembly-stimulated GTP hydrolysis is achieved through G domain dimerization. A sodium ion present in the active site suggests that dynamin uses a cation to compensate for the developing negative charge in the transition state in the absence of an arginine finger. Structural comparison to the rat dynamin G domain reveals key conformational changes that promote G domain dimerization and stimulated hydrolysis. The structure of the GTPase-GED fusion protein dimer provides insight into the mechanisms underlying dynamin-catalysed membrane fission.

  15. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

    Science.gov (United States)

    Pohlmeyer, Eric A; Oby, Emily R; Perreault, Eric J; Solla, Sara A; Kilgore, Kevin L; Kirsch, Robert F; Miller, Lee E

    2009-06-15

    Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES) of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  16. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

    Directory of Open Access Journals (Sweden)

    Eric A Pohlmeyer

    Full Text Available Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  17. Stimulated Brillouin scattering enhancement in silicon inverse opal waveguides

    CERN Document Server

    Smith, M J A; de Sterke, C Martijn; Lapine, M; Kuhlmey, B T; Poulton, C G

    2016-01-01

    Silicon is an ideal material for on-chip applications, however its poor acoustic properties limit its performance for important optoacoustic applications, particularly for Stimulated Brillouin Scattering (SBS). We theoretically show that silicon inverse opals exhibit a strongly improved acoustic performance that enhances the bulk SBS gain coefficient by more than two orders of magnitude. We also design a waveguide that incorporates silicon inverse opals and which has SBS gain values that are comparable with chalcogenide glass waveguides. This research opens new directions for opto-acoustic applications in on-chip material systems.

  18. Model-based rational feedback controller design for closed-loop deep brain stimulation of Parkinson's disease

    Science.gov (United States)

    Gorzelic, P.; Schiff, S. J.; Sinha, A.

    2013-04-01

    Objective. To explore the use of classical feedback control methods to achieve an improved deep brain stimulation (DBS) algorithm for application to Parkinson's disease (PD). Approach. A computational model of PD dynamics was employed to develop model-based rational feedback controller design. The restoration of thalamocortical relay capabilities to patients suffering from PD is formulated as a feedback control problem with the DBS waveform serving as the control input. Two high-level control strategies are tested: one that is driven by an online estimate of thalamic reliability, and another that acts to eliminate substantial decreases in the inhibition from the globus pallidus interna (GPi) to the thalamus. Control laws inspired by traditional proportional-integral-derivative (PID) methodology are prescribed for each strategy and simulated on this computational model of the basal ganglia network. Main Results. For control based upon thalamic reliability, a strategy of frequency proportional control with proportional bias delivered the optimal control achieved for a given energy expenditure. In comparison, control based upon synaptic inhibitory output from the GPi performed very well in comparison with those of reliability-based control, with considerable further reduction in energy expenditure relative to that of open-loop DBS. The best controller performance was amplitude proportional with derivative control and integral bias, which is full PID control. We demonstrated how optimizing the three components of PID control is feasible in this setting, although the complexity of these optimization functions argues for adaptive methods in implementation. Significance. Our findings point to the potential value of model-based rational design of feedback controllers for Parkinson's disease.

  19. Applications of holographic on-chip microscopy (Conference Presentation)

    Science.gov (United States)

    Ozcan, Aydogan

    2017-02-01

    My research focuses on the use of computation/algorithms to create new optical microscopy, sensing, and diagnostic techniques, significantly improving existing tools for probing micro- and nano-objects while also simplifying the designs of these analysis tools. In this presentation, I will introduce a set of computational microscopes which use lens-free on-chip imaging to replace traditional lenses with holographic reconstruction algorithms. Basically, 3D images of specimens are reconstructed from their "shadows" providing considerably improved field-of-view (FOV) and depth-of-field, thus enabling large sample volumes to be rapidly imaged, even at nanoscale. These new computational microscopes routinely generate chip. The field-of-view of these computational microscopes is equal to the active-area of the sensor-array, easily reaching, for example, chips, respectively. In addition to this remarkable increase in throughput, another major benefit of this technology is that it lends itself to field-portable and cost-effective designs which easily integrate with smartphones to conduct giga-pixel tele-pathology and microscopy even in resource-poor and remote settings where traditional techniques are difficult to implement and sustain, thus opening the door to various telemedicine applications in global health. Through the development of similar computational imagers, I will also report the discovery of new 3D swimming patterns observed in human and animal sperm. One of this newly discovered and extremely rare motion is in the form of "chiral ribbons" where the planar swings of the sperm head occur on an osculating plane creating in some cases a helical ribbon and in some others a twisted ribbon. Shedding light onto the statistics and biophysics of various micro-swimmers' 3D motion, these results provide an important example of how biomedical imaging significantly benefits from emerging computational algorithms/theories, revolutionizing existing tools for observing

  20. Impulse control and related disorders in Parkinson's disease patients treated with bilateral subthalamic nucleus stimulation: a review.

    Science.gov (United States)

    Broen, Martijn; Duits, Annelien; Visser-Vandewalle, Veerle; Temel, Yasin; Winogrodzka, Ania

    2011-07-01

    Recently, impulse control and related disorders including punding and the dopamine dysregulation syndrome (DDS) have been increasingly recognized in treated patients with Parkinson's disease (PD). Especially the impulse control disorders (ICD) such as pathological gambling, hypersexuality, compulsive eating and buying may have dramatic repercussions on family, personal and professional life. Drug replacement therapy (DRT) is believed to play an important role in the onset of these behavioral disturbances. Although deep brain stimulation (DBS) of the subthalamic nucleus (STN) might be a therapeutic option for those patients with DRT-related behavior, it may also induce ICD. So far, little is known about the relationship between STN DBS and impulse control and related disorders. Our aim was to review the current knowledge on this relationship in PD patients. The available studies showed that stimulation of the STN is associated with both favorable and negative outcome in terms of impulse control and related disorders. Preoperative disorders may resolve or improve after STN DBS, but these can also worsen or show no change at all. Moreover, STN DBS can also reveal or even induce ICD. Possible explanations for this variability are proposed and suggestions for clinical management are given.