WorldWideScience

Sample records for brain visual prosthetics

  1. Brain responses to acupuncture stimulation in the prosthetic hand of an amputee patient.

    Science.gov (United States)

    Lee, In-Seon; Jung, Won-Mo; Lee, Ye-Seul; Wallraven, Christian; Chae, Younbyoung

    2015-10-01

    This report describes the brain responses to acupuncture in an upper limb amputee patient. A 62-year-old male had previously undergone a lower left arm amputation following an electrical accident. Using functional MRI, we investigated brain responses to acupuncture stimulation in the aforementioned amputee under three conditions: (a) intact hand, (b) prosthetic hand (used by the patient), and (c) fake fabric hand. The patient described greater de qi sensation when he received acupuncture stimulation in his prosthetic hand compared to a fake hand, with both stimulations performed in a similar manner. We found enhanced brain activation in the insula and sensorimotor cortex in response to acupuncture stimulation in the amputee's prosthetic hand, while there was only minimal activation in the visual cortex in response to acupuncture stimulation in a fake hand. The enhanced brain responses to acupuncture stimulation of the patient's prosthetic hand might be derived from cortical reorganisation, as he has been using his prosthetic hand for over 40 years. Our findings suggest the possible use of acupuncture stimulation in a prosthetic hand as an enhanced sensory feedback mechanism, which may represent a new treatment approach for phantom limb pain.

  2. Multimodal Brain Visualization

    OpenAIRE

    Nadeem, Saad; Kaufman, Arie

    2016-01-01

    Current connectivity diagrams of human brain image data are either overly complex or overly simplistic. In this work we introduce simple yet accurate interactive visual representations of multiple brain image structures and the connectivity among them. We map cortical surfaces extracted from human brain magnetic resonance imaging (MRI) data onto 2D surfaces that preserve shape (angle), extent (area), and spatial (neighborhood) information for 2D (circular disk) and 3D (spherical) mapping, spl...

  3. Multimodal brain visualization

    Science.gov (United States)

    Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Current connectivity diagrams of human brain image data are either overly complex or overly simplistic. In this work we introduce simple yet accurate interactive visual representations of multiple brain image structures and the connectivity among them. We map cortical surfaces extracted from human brain magnetic resonance imaging (MRI) data onto 2D surfaces that preserve shape (angle), extent (area), and spatial (neighborhood) information for 2D (circular disk) and 3D (spherical) mapping, split these surfaces into separate patches, and cluster functional and diffusion tractography MRI connections between pairs of these patches. The resulting visualizations are easier to compute on and more visually intuitive to interact with than the original data, and facilitate simultaneous exploration of multiple data sets, modalities, and statistical maps.

  4. Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats

    Science.gov (United States)

    Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

    2016-01-01

    Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal’s retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals. PMID:27731346

  5. Prosthetic Engineering

    Science.gov (United States)

    ... Overview CoE for Limb Loss Prevention and Prosthetic Engineering Menu Menu VA Center of Excellence for Limb ... ZIP code here Enter ZIP code here Prosthetic Engineering - Overview Our aim is to improve prosthetic prescription ...

  6. [Synchronized, oscillatory brain activity in visual perception].

    Science.gov (United States)

    Braunitzer, Gábor

    2008-09-30

    The present study investigates one of the most promising developments of the brain-mind question, namely the possible links between synchronized oscillatory brain activity and certain (visual) perceptual processes. Through a review of the relevant literature, the author introduces the reader to the most important theories of coherent perception ('binding'), and makes an attempt to show how synchronization of EEG-registrable oscillatory activities from various frequency bands might explain binding. Finally, a number of clinical problems are also mentioned, regarding which the presented theoretical framework might deserve further consideration. PMID:18841649

  7. Psychophysical testing of visual prosthetic devices: a call to establish a multi-national joint task force

    Science.gov (United States)

    Rizzo, Joseph F., III; Ayton, Lauren N.

    2014-04-01

    Recent advances in the field of visual prostheses, as showcased in this special feature of Journal of Neural Engineering , have led to promising results from clinical trials of a number of devices. However, as noted by these groups there are many challenges involved in assessing vision of people with profound vision loss. As such, it is important that there is consistency in the methodology and reporting standards for clinical trials of visual prostheses and, indeed, the broader vision restoration research field. Two visual prosthesis research groups, the Boston Retinal Implant Project (BRIP) and Bionic Vision Australia (BVA), have agreed to work cooperatively to establish a multi-national Joint Task Force. The aim of this Task Force will be to develop a consensus statement to guide the methods used to conduct and report psychophysical and clinical results of humans who receive visual prosthetic devices. The overarching goal is to ensure maximum benefit to the implant recipients, not only in the outcomes of the visual prosthesis itself, but also in enabling them to obtain accurate information about this research with ease. The aspiration to develop a Joint Task Force was first promulgated at the inaugural 'The Eye and the Chip' meeting in September 2000. This meeting was established to promote the development of the visual prosthetic field by applying the principles of inclusiveness, openness, and collegiality among the growing body of researchers in this field. These same principles underlie the intent of this Joint Task Force to enhance the quality of psychophysical research within our community. Despite prior efforts, a critical mass of interested parties could not congeal. Renewed interest for developing joint guidelines has developed recently because of a growing awareness of the challenges of obtaining reliable measurements of visual function in patients who are severely visually impaired (in whom testing is inherently noisy), and of the importance of

  8. Electrical stimulation of the brain and the development of cortical visual prostheses: An historical perspective.

    Science.gov (United States)

    Lewis, Philip M; Rosenfeld, Jeffrey V

    2016-01-01

    Rapid advances are occurring in neural engineering, bionics and the brain-computer interface. These milestones have been underpinned by staggering advances in micro-electronics, computing, and wireless technology in the last three decades. Several cortically-based visual prosthetic devices are currently being developed, but pioneering advances with early implants were achieved by Brindley followed by Dobelle in the 1960s and 1970s. We have reviewed these discoveries within the historical context of the medical uses of electricity including attempts to cure blindness, the discovery of the visual cortex, and opportunities for cortex stimulation experiments during neurosurgery. Further advances were made possible with improvements in electrode design, greater understanding of cortical electrophysiology and miniaturisation of electronic components. Human trials of a new generation of prototype cortical visual prostheses for the blind are imminent. This article is part of a Special Issue entitled Hold Item. PMID:26348986

  9. Brain-Machine Interface to Control a Prosthetic Arm with Monkey ECoGs during Periodic Movements

    Directory of Open Access Journals (Sweden)

    Soichiro eMorishita

    2014-12-01

    Full Text Available Brain Machine Interfaces (BMIs are promising technologies to rehabilitate the function of upper limbs in severely paralyzed patients. We succeeded in developing a BMI prosthetic arm for a monkey implanted with electrocorticogram (ECoG electrodes and trained in a reaching task. It had stability in preventing the misclassification of ECoG patterns. However, the latency was about 200 ms as a trade-off for the stability. To improve the response of this BMI prosthetic arm, the generation of a trigger event by decoding muscle activity was adopted. It was performed to predict integrated electromyograms (iEMGs from the ECoGs. Experiments were conducted to verify the availability of this method, and the results confirmed that the proposed method was superior to the conventional one. In addition, a performance test of the proposed method with actually achieved iEMGs instead of predicted iEMGs was performed, and we found that the motor intention is finely expressed through estimated muscle activity from brain activity rather than actual muscle activity.

  10. Rehabilitation of damage to the visual brain

    OpenAIRE

    Ajina, S; Kennard, C

    2012-01-01

    Homonymous visual field loss is a common consequence of stroke and traumatic brain injury. It is associated with an adverse functional prognosis and has implications on day-to-day activities such as driving, reading, and safe navigation. Early recovery is expected in around half of cases, and may be associated with a return in V1 activity. In stable disease, recovery is unlikely beyond three and certainly six months. Rehabilitative approaches generally target three main areas, encompassing a ...

  11. Brain Activity in Response to Visual Symmetry

    Directory of Open Access Journals (Sweden)

    Marco Bertamini

    2014-12-01

    Full Text Available A number of studies have explored visual symmetry processing by measuring event related potentials and neural oscillatory activity. There is a sustained posterior negativity (SPN related to the presence of symmetry. There is also functional magnetic resonance imaging (MRI activity in extrastriate visual areas and in the lateral occipital complex. We summarise the evidence by answering six questions. (1 Is there an automatic and sustained response to symmetry in visual areas? Answer: Yes, and this suggests automatic processing of symmetry. (2 Which brain areas are involved in symmetry perception? Answer: There is an extended network from extrastriate areas to higher areas. (3 Is reflection special? Answer: Reflection is the optimal stimulus for a more general regularity-sensitive network. (4 Is the response to symmetry independent of view angle? Answer: When people classify patterns as symmetrical or random, the response to symmetry is view-invariant. When people attend to other dimensions, the network responds to residual regularity in the image. (5 How are brain rhythms in the two hemispheres altered during symmetry perception? Answer: Symmetry processing (rather than presence produces more alpha desynchronization in the right posterior regions. Finally, (6 does symmetry processing produce positive affect? Answer: Not in the strongest sense, but behavioural measures reveal implicit positive evaluation of abstract symmetry.

  12. Psychophysical testing of visual prosthetic devices: a call to establish a multi-national joint task force

    Science.gov (United States)

    Rizzo, Joseph F., III; Ayton, Lauren N.

    2014-04-01

    Recent advances in the field of visual prostheses, as showcased in this special feature of Journal of Neural Engineering , have led to promising results from clinical trials of a number of devices. However, as noted by these groups there are many challenges involved in assessing vision of people with profound vision loss. As such, it is important that there is consistency in the methodology and reporting standards for clinical trials of visual prostheses and, indeed, the broader vision restoration research field. Two visual prosthesis research groups, the Boston Retinal Implant Project (BRIP) and Bionic Vision Australia (BVA), have agreed to work cooperatively to establish a multi-national Joint Task Force. The aim of this Task Force will be to develop a consensus statement to guide the methods used to conduct and report psychophysical and clinical results of humans who receive visual prosthetic devices. The overarching goal is to ensure maximum benefit to the implant recipients, not only in the outcomes of the visual prosthesis itself, but also in enabling them to obtain accurate information about this research with ease. The aspiration to develop a Joint Task Force was first promulgated at the inaugural 'The Eye and the Chip' meeting in September 2000. This meeting was established to promote the development of the visual prosthetic field by applying the principles of inclusiveness, openness, and collegiality among the growing body of researchers in this field. These same principles underlie the intent of this Joint Task Force to enhance the quality of psychophysical research within our community. Despite prior efforts, a critical mass of interested parties could not congeal. Renewed interest for developing joint guidelines has developed recently because of a growing awareness of the challenges of obtaining reliable measurements of visual function in patients who are severely visually impaired (in whom testing is inherently noisy), and of the importance of

  13. Visualizing the blind brain: brain imaging of visual field defects from early recovery to rehabilitation techniques.

    Science.gov (United States)

    Urbanski, Marika; Coubard, Olivier A; Bourlon, Clémence

    2014-01-01

    Visual field defects (VFDs) are one of the most common consequences observed after brain injury, especially after a stroke in the posterior cerebral artery territory. Less frequently, tumors, traumatic brain injury, brain surgery or demyelination can also determine various visual disabilities, from a decrease in visual acuity to cerebral blindness. Visual field defects is a factor of bad functional prognosis as it compromises many daily life activities (e.g., obstacle avoidance, driving, and reading) and therefore the patient's quality of life. Spontaneous recovery seems to be limited and restricted to the first 6 months, with the best chance of improvement at 1 month. The possible mechanisms at work could be partly due to cortical reorganization in the visual areas (plasticity) and/or partly to the use of intact alternative visual routes, first identified in animal studies and possibly underlying the phenomenon of blindsight. Despite processes of early recovery, which is rarely complete, and learning of compensatory strategies, the patient's autonomy may still be compromised at more chronic stages. Therefore, various rehabilitation therapies based on neuroanatomical knowledge have been developed to improve VFDs. These use eye-movement training techniques (e.g., visual search, saccadic eye movements), reading training, visual field restitution (the Vision Restoration Therapy, VRT), or perceptual learning. In this review, we will focus on studies of human adults with acquired VFDs, which have used different imaging techniques (Positron Emission Tomography, PET; Diffusion Tensor Imaging, DTI; functional Magnetic Resonance Imaging, fMRI; Magneto Encephalography, MEG) or neurostimulation techniques (Transcranial Magnetic Stimulation, TMS; transcranial Direct Current Stimulation, tDCS) to show brain activations in the course of spontaneous recovery or after specific rehabilitation techniques.

  14. Visualizing the blind brain: brain imaging of visual field defects from early recovery to rehabilitation techniques

    Directory of Open Access Journals (Sweden)

    Marika eUrbanski

    2014-09-01

    Full Text Available Visual field defects (VFDs are one of the most common consequences observed after brain injury, especially after a stroke in the posterior cerebral artery territory. Less frequently, tumours, traumatic brain injury, brain surgery or demyelination can also determine various visual disabilities, from a decrease in visual acuity to cerebral blindness. VFD is a factor of bad functional prognosis as it compromises many daily life activities (e.g., obstacle avoidance, driving, and reading and therefore the patient’s quality of life. Spontaneous recovery seems to be limited and restricted to the first six months, with the best chance of improvement at one month. The possible mechanisms at work could be partly due to cortical reorganization in the visual areas (plasticity and/or partly to the use of intact alternative visual routes, first identified in animal studies and possibly underlying the phenomenon of blindsight. Despite processes of early recovery, which is rarely complete, and learning of compensatory strategies, the patient’s autonomy may still be compromised at more chronic stages. Therefore, various rehabilitation therapies based on neuroanatomical knowledge have been developed to improve VFDs. These use eye-movement training techniques (e.g., visual search, saccadic eye movements, reading training, visual field restitution (the Vision Restoration Therapy, VRT, or perceptual learning. In this review, we will focus on studies of human adults with acquired VFDs, which have used different imaging techniques (Positron Emission Tomography: PET, Diffusion Tensor Imaging: DTI, functional Magnetic Resonance Imaging: fMRI, MagnetoEncephalography: MEG or neurostimulation techniques (Transcranial Magnetic Stimulation: TMS; transcranial Direct Current Stimulation, tDCS to show brain activations in the course of spontaneous recovery or after specific rehabilitation techniques.

  15. Demonstration of a Semi-Autonomous Hybrid Brain-Machine Interface using Human Intracranial EEG, Eye Tracking, and Computer Vision to Control a Robotic Upper Limb Prosthetic

    OpenAIRE

    McMullen, David P.; Hotson, Guy; Katyal, Kapil D.; Wester, Brock A.; Fifer, Matthew S; McGee, Timothy G.; Harris, Andrew; Johannes, Matthew S; Vogelstein, R. Jacob; Ravitz, Alan D.; Anderson, William S.; Thakor, Nitish V.; Crone, Nathan E.

    2013-01-01

    To increase the ability of brain-machine interfaces (BMIs) to control advanced prostheses such as the modular prosthetic limb (MPL), we are developing a novel system: the Hybrid Augmented Reality Multimodal Operation Neural Integration Environment (HARMONIE). This system utilizes hybrid input, supervisory control, and intelligent robotics to allow users to identify an object (via eye tracking and computer vision) and initiate (via brain-control) a semi-autonomous reach-grasp-and-drop of the o...

  16. Safety and effectiveness considerations for clinical studies of visual prosthetic devices

    Science.gov (United States)

    Cohen, Ethan D.

    2007-03-01

    With the advent of new designs of visual prostheses for the blind, FDA is faced with developing guidance for evaluating their engineering, safety and patient performance. Visual prostheses are considered significant risk medical devices, and their use in human clinical trials must be approved by FDA under an investigation device exemption (IDE). This paper contains a series of test topics and design issues that sponsors should consider in order to assess the safety and efficacy of their device. The IDE application includes a series of pre-clinical and clinical data sections. The pre-clinical section documents laboratory, animal and bench top performance tests of visual prostheses safety and reliability to support a human clinical trial. The materials used in constructing the implant should be biocompatible, sterile, corrosion resistant, and able to withstand any forces exerted on it during normal patient use. The clinical data section is composed of items related to patient-related evaluation of device performance. This section documents the implantation procedure, trial design, statistical analysis and how visual performance is assessed. Similar to cochlear implants, a visual prosthesis is expected to last in the body for many years, and good pre-clinical and clinical testing will help ensure its safety, durability and effectiveness.

  17. Fluorescent Nanoparticle Uptake for Brain Tumor Visualization

    Directory of Open Access Journals (Sweden)

    Rachel Tréhin

    2006-04-01

    Full Text Available Accurate delineation of tumor margins is vital to the successful surgical resection of brain tumors. We have previously developed a multimodal nanoparticle CLIO-Cy5.5, which is detectable by both magnetic resonance imaging and fluorescence, to assist in intraoperatively visualizing tumor boundaries. Here we examined the accuracy of tumor margin determination of orthotopic tumors implanted in hosts with differing immune responses to the tumor. Using a nonuser-based signal intensity method applied to fluorescent micrographs of 9L gliosarcoma green fluorescent protein (GFP tumors, mean overestimations of 2 and 24 µm were obtained using Cy5.5 fluorescence, compared to the true tumor margin determined by GFP fluorescence, in nude mice and rats, respectively. To resolve which cells internalized the nanoparticle and to quantitate degree of uptake, tumors were disaggregated and cells were analyzed by flow cytometry and fluorescence microscopy. Nanoparticle uptake was seen in both CD11b+ cells (representing activated microglia and macrophages and tumor cells in both animal models by both methods. CD11b+ cells were predominantly found at the tumor margin in both hosts, but were more pronounced at the margin in the rat model. Additional metastatic (CT26 colon and primary (Gli36 glioma brain tumor models likewise demonstrated that the nanoparticle was internalized both by tumor cells and by host cells. Together, these observations suggest that fluorescent nanoparticles provide an accurate method of tumor margin estimation based on a combination of tumor cell and host cell uptake for primary and metastatic tumors in animal model systems and offer potential for clinical translation.

  18. Generalised brain edema and brain infarct in ergotamine abuse: Visualization by CT, MR and angiography

    International Nuclear Information System (INIS)

    Abuse of ergotamine can release a generalised brain edema and brain infarctions. This can be visualized by CT, MR and angiography. The reason, however, can only be found in the patients history. (orig.)

  19. Review of Brain-Machine Interfaces Used in Neural Prosthetics with New Perspective on Somatosensory Feedback through Method of Signal Breakdown.

    Science.gov (United States)

    Vidal, Gabriel W Vattendahl; Rynes, Mathew L; Kelliher, Zachary; Goodwin, Shikha Jain

    2016-01-01

    The brain-machine interface (BMI) used in neural prosthetics involves recording signals from neuron populations, decoding those signals using mathematical modeling algorithms, and translating the intended action into physical limb movement. Recently, somatosensory feedback has become the focus of many research groups given its ability in increased neural control by the patient and to provide a more natural sensation for the prosthetics. This process involves recording data from force sensitive locations on the prosthetics and encoding these signals to be sent to the brain in the form of electrical stimulation. Tactile sensation has been achieved through peripheral nerve stimulation and direct stimulation of the somatosensory cortex using intracortical microstimulation (ICMS). The initial focus of this paper is to review these principles and link them to modern day applications such as restoring limb use to those who lack such control. With regard to how far the research has come, a new perspective for the signal breakdown concludes the paper, offering ideas for more real somatosensory feedback using ICMS to stimulate particular sensations by differentiating touch sensors and filtering data based on unique frequencies. PMID:27313959

  20. Decoding the visual and subjective contents of the human brain

    OpenAIRE

    Kamitani, Yukiyasu; Tong, Frank

    2005-01-01

    The potential for human neuroimaging to read-out the detailed contents of a person’s mental state has yet to be fully explored. We investigated whether the perception of edge orientation, a fundamental visual feature, can be decoded from human brain activity measured with functional magnetic resonance imaging (fMRI). Using statistical algorithms to classify brain states, we found that ensemble fMRI signals in early visual areas could reliably predict on individual trials which of eight stimul...

  1. Shared visual attention and memory systems in the Drosophila brain.

    Directory of Open Access Journals (Sweden)

    Bruno van Swinderen

    Full Text Available BACKGROUND: Selective attention and memory seem to be related in human experience. This appears to be the case as well in simple model organisms such as the fly Drosophila melanogaster. Mutations affecting olfactory and visual memory formation in Drosophila, such as in dunce and rutabaga, also affect short-term visual processes relevant to selective attention. In particular, increased optomotor responsiveness appears to be predictive of visual attention defects in these mutants. METHODOLOGY/PRINCIPAL FINDINGS: To further explore the possible overlap between memory and visual attention systems in the fly brain, we screened a panel of 36 olfactory long term memory (LTM mutants for visual attention-like defects using an optomotor maze paradigm. Three of these mutants yielded high dunce-like optomotor responsiveness. We characterized these three strains by examining their visual distraction in the maze, their visual learning capabilities, and their brain activity responses to visual novelty. We found that one of these mutants, D0067, was almost completely identical to dunce(1 for all measures, while another, D0264, was more like wild type. Exploiting the fact that the LTM mutants are also Gal4 enhancer traps, we explored the sufficiency for the cells subserved by these elements to rescue dunce attention defects and found overlap at the level of the mushroom bodies. Finally, we demonstrate that control of synaptic function in these Gal4 expressing cells specifically modulates a 20-30 Hz local field potential associated with attention-like effects in the fly brain. CONCLUSIONS/SIGNIFICANCE: Our study uncovers genetic and neuroanatomical systems in the fly brain affecting both visual attention and odor memory phenotypes. A common component to these systems appears to be the mushroom bodies, brain structures which have been traditionally associated with odor learning but which we propose might be also involved in generating oscillatory brain activity

  2. Visual dictionaries as intermediate features in the human brain.

    Science.gov (United States)

    Ramakrishnan, Kandan; Scholte, H Steven; Groen, Iris I A; Smeulders, Arnold W M; Ghebreab, Sennay

    2014-01-01

    The human visual system is assumed to transform low level visual features to object and scene representations via features of intermediate complexity. How the brain computationally represents intermediate features is still unclear. To further elucidate this, we compared the biologically plausible HMAX model and Bag of Words (BoW) model from computer vision. Both these computational models use visual dictionaries, candidate features of intermediate complexity, to represent visual scenes, and the models have been proven effective in automatic object and scene recognition. These models however differ in the computation of visual dictionaries and pooling techniques. We investigated where in the brain and to what extent human fMRI responses to short video can be accounted for by multiple hierarchical levels of the HMAX and BoW models. Brain activity of 20 subjects obtained while viewing a short video clip was analyzed voxel-wise using a distance-based variation partitioning method. Results revealed that both HMAX and BoW explain a significant amount of brain activity in early visual regions V1, V2, and V3. However, BoW exhibits more consistency across subjects in accounting for brain activity compared to HMAX. Furthermore, visual dictionary representations by HMAX and BoW explain significantly some brain activity in higher areas which are believed to process intermediate features. Overall our results indicate that, although both HMAX and BoW account for activity in the human visual system, the BoW seems to more faithfully represent neural responses in low and intermediate level visual areas of the brain.

  3. Visual dictionaries as intermediate features in the human brain

    Directory of Open Access Journals (Sweden)

    Kandan eRamakrishnan

    2015-01-01

    Full Text Available The human visual system is assumed to transform low level visual features to object and scene representations via features of intermediate complexity. How the brain computationally represents intermediate features is still unclear. To further elucidate this, we compared the biologically plausible HMAX model and Bag of Words (BoW model from computer vision. Both these computational models use visual dictionaries, candidate features of intermediate complexity, to represent visual scenes, and the models have been proven effective in automatic object and scene recognition. These models however differ in the computation of visual dictionaries and pooling techniques. We investigated where in the brain and to what extent human fMRI responses to short video can be accounted for by multiple hierarchical levels of the HMAX and BoW models. Brain activity of 20 subjects obtained while viewing a short video clip was analyzed voxel-wise using a distance-based variation partitioning method. Results revealed that both HMAX and BoW explain a significant amount of brain activity in early visual regions V1, V2 and V3. However BoW exhibits more consistency across subjects in accounting for brain activity compared to HMAX. Furthermore, visual dictionary representations by HMAX and BoW explain significantly some brain activity in higher areas which are believed to process intermediate features. Overall our results indicate that, although both HMAX and BoW account for activity in the human visual system, the BoW seems to more faithfully represent neural responses in low and intermediate level visual areas of the brain.

  4. Rehabilitation and Prosthetic Services

    Science.gov (United States)

    ... Therapy Mental Health Physical Medicine and Rehabilitation Services Physical Therapy Prosthetic and Sensory Aids Service Benefits Prosthetic and Sensory Aids Service General Information Prosthetic ...

  5. Visual dictionaries as intermediate features in the human brain

    NARCIS (Netherlands)

    K. Ramakrishnan; H.S. Scholte; I.I.A. Groen; A.W.M. Smeulders; S. Ghebreab

    2015-01-01

    The human visual system is assumed to transform low level visual features to object and scene representations via features of intermediate complexity. How the brain computationally represents intermediate features is still unclear. To further elucidate this, we compared the biologically plausible HM

  6. Dynamic Data Visualization with Weave and Brain Choropleths.

    Directory of Open Access Journals (Sweden)

    Dianne Patterson

    Full Text Available This article introduces the neuroimaging community to the dynamic visualization workbench, Weave (https://www.oicweave.org/, and a set of enhancements to allow the visualization of brain maps. The enhancements comprise a set of brain choropleths and the ability to display these as stacked slices, accessible with a slider. For the first time, this allows the neuroimaging community to take advantage of the advanced tools already available for exploring geographic data. Our brain choropleths are modeled after widely used geographic maps but this mashup of brain choropleths with extant visualization software fills an important neuroinformatic niche. To date, most neuroinformatic tools have provided online databases and atlases of the brain, but not good ways to display the related data (e.g., behavioral, genetic, medical, etc. The extension of the choropleth to brain maps allows us to leverage general-purpose visualization tools for concurrent exploration of brain images and related data. Related data can be represented as a variety of tables, charts and graphs that are dynamically linked to each other and to the brain choropleths. We demonstrate that the simplified region-based analyses that underlay choropleths can provide insights into neuroimaging data comparable to those achieved by using more conventional methods. In addition, the interactive interface facilitates additional insights by allowing the user to filter, compare, and drill down into the visual representations of the data. This enhanced data visualization capability is useful during the initial phases of data analysis and the resulting visualizations provide a compelling way to publish data as an online supplement to journal articles.

  7. Linking brain imaging signals to visual perception.

    Science.gov (United States)

    Welchman, Andrew E; Kourtzi, Zoe

    2013-11-01

    The rapid advances in brain imaging technology over the past 20 years are affording new insights into cortical processing hierarchies in the human brain. These new data provide a complementary front in seeking to understand the links between perceptual and physiological states. Here we review some of the challenges associated with incorporating brain imaging data into such "linking hypotheses," highlighting some of the considerations needed in brain imaging data acquisition and analysis. We discuss work that has sought to link human brain imaging signals to existing electrophysiological data and opened up new opportunities in studying the neural basis of complex perceptual judgments. We consider a range of approaches when using human functional magnetic resonance imaging to identify brain circuits whose activity changes in a similar manner to perceptual judgments and illustrate these approaches by discussing work that has studied the neural basis of 3D perception and perceptual learning. Finally, we describe approaches that have sought to understand the information content of brain imaging data using machine learning and work that has integrated multimodal data to overcome the limitations associated with individual brain imaging approaches. Together these approaches provide an important route in seeking to understand the links between physiological and psychological states.

  8. Decoding the visual and subjective contents of the human brain.

    Science.gov (United States)

    Kamitani, Yukiyasu; Tong, Frank

    2005-05-01

    The potential for human neuroimaging to read out the detailed contents of a person's mental state has yet to be fully explored. We investigated whether the perception of edge orientation, a fundamental visual feature, can be decoded from human brain activity measured with functional magnetic resonance imaging (fMRI). Using statistical algorithms to classify brain states, we found that ensemble fMRI signals in early visual areas could reliably predict on individual trials which of eight stimulus orientations the subject was seeing. Moreover, when subjects had to attend to one of two overlapping orthogonal gratings, feature-based attention strongly biased ensemble activity toward the attended orientation. These results demonstrate that fMRI activity patterns in early visual areas, including primary visual cortex (V1), contain detailed orientation information that can reliably predict subjective perception. Our approach provides a framework for the readout of fine-tuned representations in the human brain and their subjective contents. PMID:15852014

  9. BrainBrowser: distributed, web-based neurological data visualization.

    Science.gov (United States)

    Sherif, Tarek; Kassis, Nicolas; Rousseau, Marc-Étienne; Adalat, Reza; Evans, Alan C

    2014-01-01

    Recent years have seen massive, distributed datasets become the norm in neuroimaging research, and the methodologies used to analyze them have, in response, become more collaborative and exploratory. Tools and infrastructure are continuously being developed and deployed to facilitate research in this context: grid computation platforms to process the data, distributed data stores to house and share them, high-speed networks to move them around and collaborative, often web-based, platforms to provide access to and sometimes manage the entire system. BrainBrowser is a lightweight, high-performance JavaScript visualization library built to provide easy-to-use, powerful, on-demand visualization of remote datasets in this new research environment. BrainBrowser leverages modern web technologies, such as WebGL, HTML5 and Web Workers, to visualize 3D surface and volumetric neuroimaging data in any modern web browser without requiring any browser plugins. It is thus trivial to integrate BrainBrowser into any web-based platform. BrainBrowser is simple enough to produce a basic web-based visualization in a few lines of code, while at the same time being robust enough to create full-featured visualization applications. BrainBrowser can dynamically load the data required for a given visualization, so no network bandwidth needs to be waisted on data that will not be used. BrainBrowser's integration into the standardized web platform also allows users to consider using 3D data visualization in novel ways, such as for data distribution, data sharing and dynamic online publications. BrainBrowser is already being used in two major online platforms, CBRAIN and LORIS, and has been used to make the 1TB MACACC dataset openly accessible. PMID:25628562

  10. BrainBrowser: distributed, web-based neurological data visualization

    Directory of Open Access Journals (Sweden)

    Tarek eSherif

    2015-01-01

    Full Text Available Recent years have seen massive, distributed datasets become the norm in neuroimaging research, and the methodologies used analyze them have, in response, become more collaborative and exploratory. Tools and infrastructure are continuously being developed and deployed to facilitate research in this context: grid computation platforms to process the data, distributed data stores to house and share them, high-speed networks to move them around and collaborative, often web-based, platforms to provide access to and sometimes manage the entire system. BrainBrowser is a lightweight, high-performance JavaScript visualization library built to provide easy-to-use, powerful, on-demand visualization of remote datasets in this new research environment. BrainBrowser leverages modern Web technologies, such as WebGL, HTML5 and Web Workers, to visualize 3D surface and volumetric neuroimaging data in any modern web browser without requiring any browser plugins. It is thus trivial to integrate BrainBrowser into any web-based platform. BrainBrowser is simple enough to produce a basic web-based visualization in a few lines of code, while at the same time being robust enough to create full-featured visualization applications. BrainBrowser can dynamically load the data required for a given visualization, so no network bandwidth needs to be waisted on data that will not be used. BrainBrowser's integration into the standardized web platform also allows users to consider using 3D data visualization in novel ways, such as for data distribution, data sharing and dynamic online publications. BrainBrowser is already being used in two major online platforms, CBRAIN and LORIS, and has been used to make the 1TB MACACC dataset openly accessible.

  11. Mapping the visual brain: how and why

    OpenAIRE

    Bridge, H

    2010-01-01

    Over the past 15 years, techniques for identifying visual areas using magnetic resonance imaging (MRI) in human subjects have been applied widely to multiple populations. This review will cover the basic techniques of using functional MRI and very high-resolution structural MRI to determine boundaries between different areas of the visual cortex. Recent applications of these methods to ophthalmological patient populations are discussed, and the future potential applications of very high field...

  12. Dynamic functional brain networks involved in simple visual discrimination learning.

    Science.gov (United States)

    Fidalgo, Camino; Conejo, Nélida María; González-Pardo, Héctor; Arias, Jorge Luis

    2014-10-01

    Visual discrimination tasks have been widely used to evaluate many types of learning and memory processes. However, little is known about the brain regions involved at different stages of visual discrimination learning. We used cytochrome c oxidase histochemistry to evaluate changes in regional brain oxidative metabolism during visual discrimination learning in a water-T maze at different time points during training. As compared with control groups, the results of the present study reveal the gradual activation of cortical (prefrontal and temporal cortices) and subcortical brain regions (including the striatum and the hippocampus) associated to the mastery of a simple visual discrimination task. On the other hand, the brain regions involved and their functional interactions changed progressively over days of training. Regions associated with novelty, emotion, visuo-spatial orientation and motor aspects of the behavioral task seem to be relevant during the earlier phase of training, whereas a brain network comprising the prefrontal cortex was found along the whole learning process. This study highlights the relevance of functional interactions among brain regions to investigate learning and memory processes. PMID:24937013

  13. Prosthetic Feet

    Science.gov (United States)

    ... age, weight, foot size, activity level, and job needs. Here are some facts to know: Basic Prosthetic Feet There are two types of basic ... knee from buckling add weight to the prosthesis, need periodic repair and cost a little more than most basic feet are often used by people who need ...

  14. Retinal Prosthetics, Optogenetics, and Chemical Photoswitches

    OpenAIRE

    Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

    2014-01-01

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral ...

  15. Visualization of monoamine oxidase in human brain

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Volkow, N.D.; Wang, G.J.; Pappas, N.; Shea, C.; MacGregor, R.R.; Logan, J.

    1996-12-31

    Monoamine oxidase is a flavin enzyme which exists in two subtypes, MAO A and MAO B. In human brain MAO B predominates and is largely compartmentalized in cell bodies of serotonergic neurons and glia. Regional distribution of MAO B was determined by positron computed tomography with volunteers after the administration of deuterium substituted [11C]L-deprenyl. The basal ganglia and thalamus exhibited the greatest concentrations of MAO B with intermediate levels in the frontal cortex and cingulate gyrus while lowest levels were observed in the parietal and temporal cortices and cerebellum. We observed that brain MAO B increases with are in health normal subjects, however the increases were generally smaller than those revealed with post-mortem studies.

  16. Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.

    Science.gov (United States)

    Sperdin, Holger F; Spierer, Lucas; Becker, Robert; Michel, Christoph M; Landis, Theodor

    2015-04-01

    Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. PMID:25487054

  17. Unveiling the mystery of visual information processing in human brain

    CERN Document Server

    Diamant, Emanuel

    2008-01-01

    It is generally accepted that human vision is an extremely powerful information processing system that facilitates our interaction with the surrounding world. However, despite extended and extensive research efforts, which encompass many exploration fields, the underlying fundamentals and operational principles of visual information processing in human brain remain unknown. We still are unable to figure out where and how along the path from eyes to the cortex the sensory input perceived by the retina is converted into a meaningful object representation, which can be consciously manipulated by the brain. Studying the vast literature considering the various aspects of brain information processing, I was surprised to learn that the respected scholarly discussion is totally indifferent to the basic keynote question: "What is information?" in general or "What is visual information?" in particular. In the old days, it was assumed that any scientific research approach has first to define its basic departure points. ...

  18. Self-portraits of the brain: cognitive science, data visualization, and communicating brain structure and function.

    Science.gov (United States)

    Goldstone, Robert L; Pestilli, Franco; Börner, Katy

    2015-08-01

    With several large-scale human brain projects currently underway and a range of neuroimaging techniques growing in availability to researchers, the amount and diversity of data relevant for understanding the human brain is increasing rapidly. A complete understanding of the brain must incorporate information about 3D neural location, activity, timing, and task. Data mining, high-performance computing, and visualization can serve as tools that augment human intellect; however, the resulting visualizations must take into account human abilities and limitations to be effective tools for exploration and communication. In this feature review, we discuss key challenges and opportunities that arise when leveraging the sophisticated perceptual and conceptual processing of the human brain to help researchers understand brain structure, function, and behavior.

  19. Brain response to visual sexual stimuli in homosexual pedophiles

    Science.gov (United States)

    Schiffer, Boris; Krueger, Tillmann; Paul, Thomas; de Greiff, Armin; Forsting, Michael; Leygraf, Norbert; Schedlowski, Manfred; Gizewski, Elke

    2008-01-01

    Objective The neurobiological mechanisms of deviant sexual preferences such as pedophilia are largely unknown. The objective of this study was to analyze whether brain activation patterns of homosexual pedophiles differed from those of a nonpedophile homosexual control group during visual sexual stimulation. Method A consecutive sample of 11 pedophile forensic inpatients exclusively attracted to boys and 12 age-matched homosexual control participants from a comparable socioeconomic stratum underwent functional magnetic resonance imaging during a visual sexual stimulation procedure that used sexually stimulating and emotionally neutral photographs. Sexual arousal was assessed according to a subjective rating scale. Results In contrast to sexually neutral pictures, in both groups sexually arousing pictures having both homosexual and pedophile content activated brain areas known to be involved in processing visual stimuli containing emotional content, including the occipitotemporal and prefrontal cortices. However, during presentation of the respective sexual stimuli, the thalamus, globus pallidus and striatum, which correspond to the key areas of the brain involved in sexual arousal and behaviour, showed significant activation in pedophiles, but not in control subjects. Conclusions Central processing of visual sexual stimuli in homosexual pedophiles seems to be comparable to that in nonpedophile control subjects. However, compared with homosexual control subjects, activation patterns in pedophiles refer more strongly to subcortical regions, which have previously been discussed in the context of processing reward signals and also play an important role in addictive and stimulus-controlled behaviour. Thus future studies should further elucidate the specificity of these brain regions for the processing of sexual stimuli in pedophilia and should address the generally weaker activation pattern in homosexual men. PMID:18197269

  20. Visualizing the site of drug action in living human brain

    Energy Technology Data Exchange (ETDEWEB)

    Suhara, Tetsuya [National Inst. of Radiological Sciences, Chiba (Japan)

    1997-03-01

    PET is the only technique available to date to measure molecular interactions in vivo, but the basic mechanism of molecular interaction in vivo is not yet fully understood. However, PET can allow visualization of various phenomena which we can not observe with in vitro techniques. Progress in PET study will provide a new viewpoint for drug development and the study of molecular mechanism in the brain. (J.P.N.)

  1. What can fish brains tell us about visual perception?

    OpenAIRE

    Valeria Anna Sovrano

    2014-01-01

    Fish are a complex taxonomic group, whose diversity and distance from other vertebrates well suits the comparative investigation of brain and behavior: in fish species we observe substantial differences with respect to the telencephalic organization of other vertebrates and an astonishing variety in the development and complexity of pallial structures. We will concentrate on the contribution of research on fish behavioral biology for the understanding of the evolution of the visual system. We...

  2. Brain correlates of phonological recoding of visual symbols.

    Science.gov (United States)

    Madec, Sylvain; Le Goff, Kévin; Anton, Jean-Luc; Longcamp, Marieke; Velay, Jean-Luc; Nazarian, Bruno; Roth, Muriel; Courrieu, Pierre; Grainger, Jonathan; Rey, Arnaud

    2016-05-15

    Learning to read involves setting up associations between meaningless visual inputs (V) and their phonological representations (P). Here, we recorded the brain signals (ERPs and fMRI) associated with phonological recoding (i.e., V-P conversion processes) in an artificial learning situation in which participants had to learn the associations between 24 unknown visual symbols (Japanese Katakana characters) and 24 arbitrary monosyllabic names. During the learning phase on Day 1, the strength of V-P associations was manipulated by varying the proportion of correct and erroneous associations displayed during a two-alternative forced choice task. Recording event related potentials (ERPs) during the learning phase allowed us to track changes in the processing of these visual symbols as a function of the strength of V-P associations. We found that, at the end of the learning phase, ERPs were linearly affected by the strength of V-P associations in a time-window starting around 200ms post-stimulus onset on right occipital sites and ending around 345ms on left occipital sites. On Day 2, participants had to perform a matching task during an fMRI session and the strength of these V-P associations was again used as a probe for identifying brain regions related to phonological recoding. Crucially, we found that the left fusiform gyrus was gradually affected by the strength of V-P associations suggesting that this region is involved in the brain network supporting phonological recoding processes. PMID:26902821

  3. Demonstration of a semi-autonomous hybrid brain-machine interface using human intracranial EEG, eye tracking, and computer vision to control a robotic upper limb prosthetic.

    Science.gov (United States)

    McMullen, David P; Hotson, Guy; Katyal, Kapil D; Wester, Brock A; Fifer, Matthew S; McGee, Timothy G; Harris, Andrew; Johannes, Matthew S; Vogelstein, R Jacob; Ravitz, Alan D; Anderson, William S; Thakor, Nitish V; Crone, Nathan E

    2014-07-01

    To increase the ability of brain-machine interfaces (BMIs) to control advanced prostheses such as the modular prosthetic limb (MPL), we are developing a novel system: the Hybrid Augmented Reality Multimodal Operation Neural Integration Environment (HARMONIE). This system utilizes hybrid input, supervisory control, and intelligent robotics to allow users to identify an object (via eye tracking and computer vision) and initiate (via brain-control) a semi-autonomous reach-grasp-and-drop of the object by the MPL. Sequential iterations of HARMONIE were tested in two pilot subjects implanted with electrocorticographic (ECoG) and depth electrodes within motor areas. The subjects performed the complex task in 71.4% (20/28) and 67.7% (21/31) of trials after minimal training. Balanced accuracy for detecting movements was 91.1% and 92.9%, significantly greater than chance accuracies (p system improvements implemented for the second subject. Our hybrid-BMI design prevented all but one baseline false positive from initiating the system. The novel approach demonstrated in this proof-of-principle study, using hybrid input, supervisory control, and intelligent robotics, addresses limitations of current BMIs. PMID:24760914

  4. Demonstration of a semi-autonomous hybrid brain-machine interface using human intracranial EEG, eye tracking, and computer vision to control a robotic upper limb prosthetic.

    Science.gov (United States)

    McMullen, David P; Hotson, Guy; Katyal, Kapil D; Wester, Brock A; Fifer, Matthew S; McGee, Timothy G; Harris, Andrew; Johannes, Matthew S; Vogelstein, R Jacob; Ravitz, Alan D; Anderson, William S; Thakor, Nitish V; Crone, Nathan E

    2014-07-01

    To increase the ability of brain-machine interfaces (BMIs) to control advanced prostheses such as the modular prosthetic limb (MPL), we are developing a novel system: the Hybrid Augmented Reality Multimodal Operation Neural Integration Environment (HARMONIE). This system utilizes hybrid input, supervisory control, and intelligent robotics to allow users to identify an object (via eye tracking and computer vision) and initiate (via brain-control) a semi-autonomous reach-grasp-and-drop of the object by the MPL. Sequential iterations of HARMONIE were tested in two pilot subjects implanted with electrocorticographic (ECoG) and depth electrodes within motor areas. The subjects performed the complex task in 71.4% (20/28) and 67.7% (21/31) of trials after minimal training. Balanced accuracy for detecting movements was 91.1% and 92.9%, significantly greater than chance accuracies (p system improvements implemented for the second subject. Our hybrid-BMI design prevented all but one baseline false positive from initiating the system. The novel approach demonstrated in this proof-of-principle study, using hybrid input, supervisory control, and intelligent robotics, addresses limitations of current BMIs.

  5. Prosthetic synovitis.

    Science.gov (United States)

    Eftekhar, N S; Doty, S B; Johnston, A D; Parisien, M V

    1985-01-01

    The term "prosthetic synovitis" is applied to reactive changes resulting from a synovial-like membrane formed between a failed prosthesis (noninfected) and the bone interface. This report is the result of light-microscopic and clinical examination of more than 100 specimens obtained at surgery of failed previous hip replacements. The morphology and cell distribution of those tissues removed at surgery in 51 noninfected cemented total hip operations allowed a quantitative estimate of surface cell population by a "touch imprint" technique; qualitative and quantitative estimate (scale, 1 to 4+) of cell population and foreign body materials by light microscopy; and electron microscopy and biochemical analysis of selected samples. Histologic examination included the following cell population, in decreasing order of frequency: acidophilic histiocytes (95%); giant cells (80%); fibronoid material (80%); lymphocyte and plasma cells (26%); and neutrophils (8%). Microscopic examination showed that the largest particles of acrylic cement and shards of high-density polyethylene appeared to be walled off by connective tissue capsules. The majority of smaller particles were incorporated into the histiocyte/macrophage or giant cell population. Histochemistry indicated that these particles elicited "foci" of cellular activity within the synovial-like membrane. This increased activity included the appearance of increased endogenous peroxidase activity in those macrophages within the "foci"; increased betagalactosidae activity among these histiocytes; and a localization of acid phosphates activity within giant cells along the borders of inclusions within the cell cytoplasm. We conclude that wear products resulting from total hip arthroplasty, including the bone cement, can induce increased lysosomal and proteolytic activity within the histiocyte and giant cell populations. It may be important to emphasize that there were "reactive foci" within the membrane and that the entire

  6. Brain functional network connectivity based on a visual task: visual information processing-related brain regions are significantly activated in the task state

    Directory of Open Access Journals (Sweden)

    Yan-li Yang

    2015-01-01

    Full Text Available It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we investigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state. Z-values in the vision-related brain regions were calculated, confirming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental findings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

  7. Changes in brain morphology in albinism reflect reduced visual acuity.

    Science.gov (United States)

    Bridge, Holly; von dem Hagen, Elisabeth A H; Davies, George; Chambers, Claire; Gouws, Andre; Hoffmann, Michael; Morland, Antony B

    2014-07-01

    Albinism, in humans and many animal species, has a major impact on the visual system, leading to reduced acuity, lack of binocular function and nystagmus. In addition to the lack of a foveal pit, there is a disruption to the routing of the nerve fibers crossing at the optic chiasm, resulting in excessive crossing of fibers to the contralateral hemisphere. However, very little is known about the effect of this misrouting on the structure of the post-chiasmatic visual pathway, and the occipital lobes in particular. Whole-brain analyses of cortical thickness in a large cohort of subjects with albinism showed an increase in cortical thickness, relative to control subjects, particularly in posterior V1, corresponding to the foveal representation. Furthermore, mean cortical thickness across entire V1 was significantly greater in these subjects compared to controls and negatively correlated with visual acuity in albinism. Additionally, the group with albinism showed decreased gyrification in the left ventral occipital lobe. While the increase in cortical thickness in V1, also found in congenitally blind subjects, has been interpreted to reflect a lack of pruning, the decreased gyrification in the ventral extrastriate cortex may reflect the reduced input to the foveal regions of the ventral visual stream.

  8. Patient DF's visual brain in action: Visual feedforward control in visual form agnosia.

    Science.gov (United States)

    Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Barat, Masihullah; Goodale, Melvyn A

    2015-05-01

    Patient DF, who developed visual form agnosia following ventral-stream damage, is unable to discriminate the width of objects, performing at chance, for example, when asked to open her thumb and forefinger a matching amount. Remarkably, however, DF adjusts her hand aperture to accommodate the width of objects when reaching out to pick them up (grip scaling). While this spared ability to grasp objects is presumed to be mediated by visuomotor modules in her relatively intact dorsal stream, it is possible that it may rely abnormally on online visual or haptic feedback. We report here that DF's grip scaling remained intact when her vision was completely suppressed during grasp movements, and it still dissociated sharply from her poor perceptual estimates of target size. We then tested whether providing trial-by-trial haptic feedback after making such perceptual estimates might improve DF's performance, but found that they remained significantly impaired. In a final experiment, we re-examined whether DF's grip scaling depends on receiving veridical haptic feedback during grasping. In one condition, the haptic feedback was identical to the visual targets. In a second condition, the haptic feedback was of a constant intermediate width while the visual target varied trial by trial. Despite this incongruent feedback, DF still scaled her grip aperture to the visual widths of the target blocks, showing only normal adaptation to the false haptically-experienced width. Taken together, these results strengthen the view that DF's spared grasping relies on a normal mode of dorsal-stream functioning, based chiefly on visual feedforward processing.

  9. Electrophysiological recording of the brain, visualization, prediction, and interconnectivity

    Science.gov (United States)

    Talakoub, Omid

    The human brain is a complex network of interconnected neurons. The aim of neuroscience and neuroengineering is to decode the neural activity, visualize it and try to better understand how neurons communicate with each other. This dissertation comprises four contributions to the area. These four topics are discussing how functional relationship between brain activity and movement can be found and whether common features found in different regions are correlated (phase-locked). First, the method of chirplet decomposition offers a new way to visualize the time-frequency content of non-stationary signals with higher resolution than previously possible. The use of Wigner-Ville distribution together with chirplet decomposition allows a clearer visualization in terms of both the temporal and frequency details with detail higher than previously achieved using other methods including Choi-Williams and spectrogram. Second, an improved method of averaging of neural signals over repeated trials is introduced whereby slight variations in the alignment of the neural signal over time is corrected through the use of nonlinear shifts. In earlier studies, time alignment has been performed using linear shift (e.g. alignment with movement onset), but this process alone is not sufficient when the signal timing changes differently over time. To overcome this issue, nonlinear transformations were found to remove any temporal variabilities in the way the task was performed. Third, a multilinear model is demonstrated showing how limb velocity in a reach task can be predicted from neuroelectrical activity. The model, after fitting, suggested that high frequency oscillations have sufficient information for both detection of movement onset and reconstruction of its movement. The use of a linear model reduces the overall computational requirements and simplifies the reconstruction of movement kinematics. Finally, a fourth method involving the measurement of coherence over time reveals how

  10. Gaitography applied to prosthetic walking.

    Science.gov (United States)

    Roerdink, Melvyn; Cutti, Andrea G; Summa, Aurora; Monari, Davide; Veronesi, Davide; van Ooijen, Mariëlle W; Beek, Peter J

    2014-11-01

    During walking on an instrumented treadmill with an embedded force platform or grid of pressure sensors, center-of-pressure (COP) trajectories exhibit a characteristic butterfly-like shape, reflecting the medio-lateral and anterior-posterior weight shifts associated with alternating steps. We define "gaitography" as the analysis of such COP trajectories during walking (the "gaitograms"). It is currently unknown, however, if gaitography can be employed to characterize pathological gait, such as lateralized gait impairments. We therefore registered gaitograms for a heterogeneous sample of persons with a trans-femoral and trans-tibial amputation during treadmill walking at a self-selected comfortable speed. We found that gaitograms directly visualize between-person differences in prosthetic gait in terms of step width and the relative duration of prosthetic and non-prosthetic single-support stance phases. We further demonstrated that one should not only focus on the gaitogram's shape but also on the time evolution along that shape, given that the COP evolves much slower in the single-support phase than in the double-support phase. Finally, commonly used temporal and spatial prosthetic gait characteristics were derived, revealing both individual and systematic differences in prosthetic and non-prosthetic step lengths, step times, swing times, and double-support durations. Because gaitograms can be rapidly collected in an unobtrusive and markerless manner over multiple gait cycles without constraining foot placement, clinical application of gaitography seems both expedient and appealing. Studies examining the repeatability of gaitograms and evaluating gaitography-based gait characteristics against a gold standard with known validity and reliability are required before gaitography can be clinically applied.

  11. Visualization and modelling of STLmax topographic brain activity maps.

    Science.gov (United States)

    Mammone, Nadia; Principe, José C; Morabito, Francesco C; Shiau, Deng S; Sackellares, J Chris

    2010-06-15

    This paper evaluates the descriptive power of brain topography based on a dynamical parameter, the Short-Term Maximum Lyapunov Exponent (STLmax), estimated from EEG, for finding out a relationship of STLmax spatial distribution with the onset zone and with the mechanisms leading to epileptic seizures. Our preliminary work showed that visual assessment of STLmax topography exhibited a link with the location of seizure onset zone. The objective of the present work is to model the spatial distribution of STLmax in order to automatically extract these features from the maps. One-hour preictal segments from four long-term continuous EEG recordings (two scalp and two intracranial) were processed and the corresponding STLmax profiles were estimated. The spatial STLmax maps were modelled by a combination of two Gaussians functions. The parameters of the fitted model allow automatic extraction of quantitative information about the spatial distribution of STLmax: the EEG signal recorded from the brain region where seizures originate exhibited low-STLmax levels, long before the seizure onset, in 3 out of 4 patients (1 out of 2 of scalp patients and 2 out of 2 in intracranial patients). Topographic maps extracted directly from the EEG power did not provide useful information about the location, therefore we conclude that the analysis so far carried out suggests the possibility of using a model of STLmax topography as a tool for monitoring the evolution of epileptic brain dynamics. In the future, a more elaborate approach will be investigated in order to improve the specificity of the method.

  12. Microprocessor prosthetic knees.

    Science.gov (United States)

    Berry, Dale

    2006-02-01

    This article traces the development of microprocessor prosthetic knees from early research in the 1970s to the present. Read about how microprocessor knees work, functional options, patient selection, and the future of this prosthetic.

  13. Control of Visual Selection during Visual Search in the Human Brain

    OpenAIRE

    Olma, Manuel C.; Donner, Tobias H.; Brandt, Stephan A.

    2007-01-01

    How do we find a target object in a cluttered visual scene? Targets carrying unique salient features can be found in parallel without directing attention, whereas targets defined by feature conjunctions or non-salient features need to be scrutinized in a serial attentional process in order to be identified. In this article, we review a series of experiments in which we used fMRI to probe the neural basis of this active search process in the human brain. In all experiments, we compared the fMR...

  14. Pursuing prosthetic electronic skin.

    Science.gov (United States)

    Chortos, Alex; Liu, Jia; Bao, Zhenan

    2016-09-01

    Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals. PMID:27376685

  15. Pursuing prosthetic electronic skin

    Science.gov (United States)

    Chortos, Alex; Liu, Jia; Bao, Zhenan

    2016-09-01

    Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.

  16. Brain activity patterns uniquely supporting visual feature integration after traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Anjali eRaja Beharelle

    2011-12-01

    Full Text Available Traumatic brain injury (TBI patients typically respond more slowly and with more variability than controls during tasks of attention requiring speeded reaction time. These behavioral changes are attributable, at least in part, to diffuse axonal injury (DAI, which affects integrated processing in distributed systems. Here we use a multivariate method sensitive to distributed neural activity to compare brain activity patterns of patients with chronic phase moderate-to-severe TBI to those of controls during performance on a visual feature-integration task assessing complex attentional processes that has previously shown sensitivity to TBI. The TBI patients were carefully screened to be free of large focal lesions that can affect performance and brain activation independently of DAI. The task required subjects to hold either one or three features of a target in mind while suppressing responses to distracting information. In controls, the multi-feature condition activated a distributed network including limbic, prefrontal, and medial temporal structures. TBI patients engaged this same network in the single-feature and baseline conditions. In multi-feature presentations, TBI patients alone activated additional frontal, parietal, and occipital regions. These results are consistent with neuroimaging studies using tasks assessing different cognitive domains, where increased spread of brain activity changes was associated with TBI. Our results also extend previous findings that brain activity for relatively moderate task demands in TBI patients is similar to that associated with of high task demands in controls.

  17. BrainFrame: a knowledge visualization system for the neurosciences

    Science.gov (United States)

    Barnes, Steven J.; Shaw, Chris D.

    2009-01-01

    Neuroscience has benefited from an explosion of new experimental techniques; many have only become feasible in the wake of improvements in computing speed and data storage. At the same time, these new computation-intensive techniques have led to a growing gulf between the data and the knowledge extracted from those data. That is, in the neurosciences there is a paucity of effective knowledge management techniques and an accelerating accumulation of experimental data. The purpose of the project described in the present paper is to create a visualization of the knowledge base of the neurosciences. At run-time, this 'BrainFrame' project accesses several web-based ontologies and generates a semantically zoomable representation of any one of many levels of the human nervous system.

  18. Visualizing Iron Deposition in Multiple Sclerosis Cadaver Brains

    International Nuclear Information System (INIS)

    Aim: To visualize and validate iron deposition in two cases of multiple sclerosis using rapid scanning X-Ray Fluorescence (RS-XRF) and Susceptibility Weighted Imaging (SWI). Material and Methods: Two (2) coronal cadaver brain slices from patients clinically diagnosed with multiple sclerosis underwent magnetic resonance imaging (MRI), specifically SWI to image iron content. To confirm the presence of iron deposits and the absence of zinc-rich myelin in lesions, iron and zinc were mapped using RS-XRF. Results: MS lesions were visualized using FLAIR and correlated with the absence of zinc by XRF. XRF and SWI showed that in the first MS case, there were large iron deposits proximal to the draining vein of the caudate nucleus as well as iron deposits associated with blood vessels throughout the globus pallidus. Less iron was seen in association with lesions than in the basal ganglia. The presence of larger amounts of iron correlated reasonably well between RS-XRF and SWI. In the second case, the basal ganglia appeared normal and acute perivascular iron deposition was absent. Conclusion: Perivascular iron deposition is seen in some but not all MS cases, giving credence to the use of SWI to assess iron involvement in MS pathology in vivo.

  19. Visualizing Iron Deposition in Multiple Sclerosis Cadaver Brains

    Energy Technology Data Exchange (ETDEWEB)

    Habib, A.C.; Zheng, W.; Haacke, E.M.; Webb, S.; Nichol, H.; /SLAC

    2012-07-17

    To visualize and validate iron deposition in two cases of multiple sclerosis using rapid scanning X-Ray Fluorescence (RS-XRF) and Susceptibility Weighted Imaging (SWI). Two (2) coronal cadaver brain slices from patients clinically diagnosed with multiple sclerosis underwent magnetic resonance imaging (MRI), specifically SWI to image iron content. To confirm the presence of iron deposits and the absence of zinc-rich myelin in lesions, iron and zinc were mapped using RS-XRF. MS lesions were visualized using FLAIR and correlated with the absence of zinc by XRF. XRF and SWI showed that in the first MS case, there were large iron deposits proximal to the draining vein of the caudate nucleus as well as iron deposits associated with blood vessels throughout the globus pallidus. Less iron was seen in association with lesions than in the basal ganglia. The presence of larger amounts of iron correlated reasonably well between RS-XRF and SWI. In the second case, the basal ganglia appeared normal and acute perivascular iron deposition was absent. Perivascular iron deposition is seen in some but not all MS cases, giving credence to the use of SWI to assess iron involvement in MS pathology in vivo.

  20. Exploration and visualization of gene expression with neuroanatomy in the adult mouse brain

    OpenAIRE

    Pathak Sayan; Thompson Carol; Ng Lydia; Lau Christopher; Kuan Leonard; Jones Allan; Hawrylycz Mike

    2008-01-01

    Abstract Background Spatially mapped large scale gene expression databases enable quantitative comparison of data measurements across genes, anatomy, and phenotype. In most ongoing efforts to study gene expression in the mammalian brain, significant resources are applied to the mapping and visualization of data. This paper describes the implementation and utility of Brain Explorer, a 3D visualization tool for studying in situ hybridization-based (ISH) expression patterns in the Allen Brain At...

  1. Networked neuroscience : brain scans and visual knowing at the intersection of atlases and databases

    NARCIS (Netherlands)

    Beaulieu, Anne; de Rijcke, Sarah; Coopmans, Catelijne; Woolgar, Steve

    2014-01-01

    This chapter discusses the development of authoritative collections of brain scans known as “brain atlases”, focusing in particular on how such scans are constituted as authoritative visual objects. Three dimensions are identified: first, brain scans are parts of suites of networked technologies rat

  2. Prevention of Prosthetic Dentistry

    Directory of Open Access Journals (Sweden)

    Eremin O.V.

    2011-03-01

    Full Text Available Prevention in prosthetic dentistry is not just a regular oral hygiene and the prevention of caries in the early stages of its development. The initial goal of orthopedic and dental should be the ability to convey to the patient's sense of pros-thetics that proteziruya one saved more. An example is included prosthetic dental arch defects with bridges or single artificial crowns on implants that will prevent movement of teeth and the continuity of the dentition

  3. Brain lateralization involved in visual recognition of conspecifics in coral reef fish at recruitment

    OpenAIRE

    Roux, Natacha; Duran, Emilio; Lanyon, Rynae G.; Frederich, Bruno; Berthe, Cécile; Besson, Marc; Dixson, Danielle L.; Lecchini, David

    2016-01-01

    In vertebrates, brain functional asymmetries are widespread and increase brain performance. Some species of fishes are known to have brain asymmetries; however, little information is available on brain lateralization in coral reef fishes and the impact this could have during the recruitment phase. In this study, soldierfish, Myripristis pralinia, at the larval and juvenile stage recognized conspecifics through visual cues. Larvae with the ablation of either the right or left telencephalic ...

  4. Assessment the Plasticity of Cortical Brain Theory through Visual Memory in Deaf and Normal Students

    Directory of Open Access Journals (Sweden)

    Ali Ghanaee-Chamanabad

    2012-10-01

    Full Text Available Background: The main aim of this research was to assess the differences of visual memory in deaf and normal students according to plasticity of cortical brain.Materials and Methods: This is an ex-post factor research. Benton visual test was performed by two different ways on 46 students of primary school. (22 deaf and 24 normal students. The t-student was used to analysis the data. Results: The visual memory in deaf students was significantly higher than the similar normal students (not deaf.While the action of visual memory in deaf girls was risen in comparison to normal girls in both ways, the deaf boys presented the better action in just one way of the two performances of Benton visual memory test.Conclusion: The action of plasticity of brain shows that the brain of an adult is dynamic and there are some changes in it. This brain plasticity has not limited to sensory somatic systems. Therefore according to plasticity of cortical brain theory, the deaf students due to the defect of hearing have increased the visual the visual inputs which developed the procedural visual memory.

  5. Reading visually embodied meaning from the brain: Visually grounded computational models decode visual-object mental imagery induced by written text.

    Science.gov (United States)

    Anderson, Andrew James; Bruni, Elia; Lopopolo, Alessandro; Poesio, Massimo; Baroni, Marco

    2015-10-15

    Embodiment theory predicts that mental imagery of object words recruits neural circuits involved in object perception. The degree of visual imagery present in routine thought and how it is encoded in the brain is largely unknown. We test whether fMRI activity patterns elicited by participants reading objects' names include embodied visual-object representations, and whether we can decode the representations using novel computational image-based semantic models. We first apply the image models in conjunction with text-based semantic models to test predictions of visual-specificity of semantic representations in different brain regions. Representational similarity analysis confirms that fMRI structure within ventral-temporal and lateral-occipital regions correlates most strongly with the image models and conversely text models correlate better with posterior-parietal/lateral-temporal/inferior-frontal regions. We use an unsupervised decoding algorithm that exploits commonalities in representational similarity structure found within both image model and brain data sets to classify embodied visual representations with high accuracy (8/10) and then extend it to exploit model combinations to robustly decode different brain regions in parallel. By capturing latent visual-semantic structure our models provide a route into analyzing neural representations derived from past perceptual experience rather than stimulus-driven brain activity. Our results also verify the benefit of combining multimodal data to model human-like semantic representations.

  6. Three-dimensional X-ray visualization of axonal tracts in mouse brain hemisphere

    CERN Document Server

    Mizutani, Ryuta; Ohtsuka, Masato; Miura, Hiromi; Hoshino, Masato; Takeuchi, Akihisa; Uesugi, Kentaro

    2016-01-01

    Neurons transmit active potentials through axons, which are essential for the brain to function. In this study, the axonal networks of the murine brain were visualized with X-ray tomographic microscopy, also known as X-ray microtomography or micro-CT. Murine brain samples were freeze-dried to reconstitute the intrinsic contrast of tissue constituents and subjected to X-ray visualization. A whole brain hemisphere visualized by absorption contrast illustrated three-dimensional structures including those of the striatum, corpus callosum, and anterior commissure. Axonal tracts observed in the striatum start from the basal surface of the cerebral cortex and end at various positions in the basal ganglia. The distribution of X-ray attenuation coefficients indicated that differences in water and phospholipid content between the myelin sheath and surrounding tissue constituents account for the observed contrast. A rod-shaped cutout of brain tissue was also analyzed with a phase retrieval method, wherein tissue microst...

  7. Mathematical Models of Visual Information Processing in the Human Brain and Applications to Image Processing

    OpenAIRE

    Arai, Hitoshi

    2013-01-01

    In this lecture I give a survey of joint works of Hitoshi Arai and Shinobu Arai. The main purpose of our study is to construct mathematical models of visual information processing in the brain, and to give applications to image processing. On the past few decades, several studies have been made on mathematical models of visual information processing in the human brain. Our new models are constructed by using simple pinwheel framelets ([4]) and pinwheel framelets ([6]), which are a new class o...

  8. Invariance of brain-wave representations of simple visual images and their names.

    Science.gov (United States)

    Suppes, P; Han, B; Epelboim, J; Lu, Z L

    1999-12-01

    In two experiments, electric brain waves of 14 subjects were recorded under several different conditions to study the invariance of brain-wave representations of simple patches of colors and simple visual shapes and their names, the words blue, circle, etc. As in our earlier work, the analysis consisted of averaging over trials to create prototypes and test samples, to both of which Fourier transforms were applied, followed by filtering and an inverse transformation to the time domain. A least-squares criterion of fit between prototypes and test samples was used for classification. The most significant results were these. By averaging over different subjects, as well as trials, we created prototypes from brain waves evoked by simple visual images and test samples from brain waves evoked by auditory or visual words naming the visual images. We correctly recognized from 60% to 75% of the test-sample brain waves. The general conclusion is that simple shapes such as circles and single-color displays generate brain waves surprisingly similar to those generated by their verbal names. These results, taken together with extensive psychological studies of auditory and visual memory, strongly support the solution proposed for visual shapes, by Bishop Berkeley and David Hume in the 18th century, to the long-standing problem of how the mind represents simple abstract ideas.

  9. Involvement of the right inferior longitudinal fascicle in visual hemiagnosia: a brain stimulation mapping study.

    Science.gov (United States)

    Fernández Coello, Alejandro; Duvaux, Sophie; De Benedictis, Alessandro; Matsuda, Ryosuke; Duffau, Hugues

    2013-01-01

    Neural foundations underlying visual agnosia are poorly understood. The authors present the case of a patient who underwent awake surgery for a right basal temporooccipital low-grade glioma in which direct electrostimulation was used both at the cortical and subcortical level. Brain mapping over the inferior longitudinal fascicle generated contralateral visual hemiagnosia. These original findings are in agreement with recent tractography data that have confirmed the existence of an occipitotemporal pathway connecting occipital visual input to higher-level processing in temporal lobe structures. This is the first report of a true transient visual hemiagnosia elicited through electrostimulation, supporting the crucial role of inferior longitudinal fascicle in visual recognition.

  10. Exploration and visualization of gene expression with neuroanatomy in the adult mouse brain

    Directory of Open Access Journals (Sweden)

    Pathak Sayan

    2008-03-01

    Full Text Available Abstract Background Spatially mapped large scale gene expression databases enable quantitative comparison of data measurements across genes, anatomy, and phenotype. In most ongoing efforts to study gene expression in the mammalian brain, significant resources are applied to the mapping and visualization of data. This paper describes the implementation and utility of Brain Explorer, a 3D visualization tool for studying in situ hybridization-based (ISH expression patterns in the Allen Brain Atlas, a genome-wide survey of 21,000 expression patterns in the C57BL6J adult mouse brain. Results Brain Explorer enables users to visualize gene expression data from the C57Bl/6J mouse brain in 3D at a resolution of 100 μm3, allowing co-display of several experiments as well as 179 reference neuro-anatomical structures. Brain Explorer also allows viewing of the original ISH images referenced from any point in a 3D data set. Anatomic and spatial homology searches can be performed from the application to find data sets with expression in specific structures and with similar expression patterns. This latter feature allows for anatomy independent queries and genome wide expression correlation studies. Conclusion These tools offer convenient access to detailed expression information in the adult mouse brain and the ability to perform data mining and visualization of gene expression and neuroanatomy in an integrated manner.

  11. GIANT PROSTHETIC VALVE THROMBUS

    Directory of Open Access Journals (Sweden)

    Prashanth Kumar

    2015-04-01

    Full Text Available Mechanical prosthetic valves are predisposed to bleeding, thrombosis & thromboembolic complications. Overall incidence of thromboembolic complications is 1% per year who are on oral anticoagulants, whereas bleeding complications incidence is 0.5% to 6.6% per year. 1, 2 Minimization of Scylla of thromboembolic & Charybdis of bleeding complication needs a balancing act of optimal antithrombotic therapy. We are reporting a case of middle aged male patient with prosthetic mitral valve presenting in heart failure. Patient had discontinued anticoagulants, as he had subdural hematoma in the past. He presented to our institute with a giant prosthetic valve thrombus.

  12. Visual and somatic sensory feedback of brain activity for intuitive surgical robot manipulation.

    Science.gov (United States)

    Miura, Satoshi; Matsumoto, Yuya; Kobayashi, Yo; Kawamura, Kazuya; Nakashima, Yasutaka; Fujie, Masakatsu G

    2015-01-01

    This paper presents a method to evaluate the hand-eye coordination of the master-slave surgical robot by measuring the activation of the intraparietal sulcus in users brain activity during controlling virtual manipulation. The objective is to examine the changes in activity of the intraparietal sulcus when the user's visual or somatic feedback is passed through or intercepted. The hypothesis is that the intraparietal sulcus activates significantly when both the visual and somatic sense pass feedback, but deactivates when either visual or somatic is intercepted. The brain activity of three subjects was measured by the functional near-infrared spectroscopic-topography brain imaging while they used a hand controller to move a virtual arm of a surgical simulator. The experiment was performed several times with three conditions: (i) the user controlled the virtual arm naturally under both visual and somatic feedback passed, (ii) the user moved with closed eyes under only somatic feedback passed, (iii) the user only gazed at the screen under only visual feedback passed. Brain activity showed significantly better control of the virtual arm naturally (pmoving with closed eyes or only gazing among all participants. In conclusion, the brain can activate according to visual and somatic sensory feedback agreement.

  13. COSFIRE : A Brain-Inspired Approach to Visual Pattern Recognition

    NARCIS (Netherlands)

    Azzopardi, G.; Petkov, N.

    2014-01-01

    The primate visual system has an impressive ability to generalize and to discriminate between numerous objects and it is robust to many geometrical transformations as well as lighting conditions. The study of the visual system has been an active reasearch field in neuropysiology for more than half a

  14. Prosthetics and Related Technology

    Science.gov (United States)

    ... forms of retinal blindness. Source: Boston Retinal Implant Project, funded in part by VA. VA Prosthetics Research ... their injuries. For questions or additional copies contact: R&D Communications (12) 103 South Gay Street, Ste. 517 ...

  15. Visual image reconstruction from human brain activity: A modular decoding approach

    International Nuclear Information System (INIS)

    Brain activity represents our perceptual experience. But the potential for reading out perceptual contents from human brain activity has not been fully explored. In this study, we demonstrate constraint-free reconstruction of visual images perceived by a subject, from the brain activity pattern. We reconstructed visual images by combining local image bases with multiple scales, whose contrasts were independently decoded from fMRI activity by automatically selecting relevant voxels and exploiting their correlated patterns. Binary-contrast, 10 x 10-patch images (2100 possible states), were accurately reconstructed without any image prior by measuring brain activity only for several hundred random images. The results suggest that our approach provides an effective means to read out complex perceptual states from brain activity while discovering information representation in multi-voxel patterns.

  16. Brain bases of the automaticity via visual search task

    OpenAIRE

    Bueichekú Bohabonay, Elisenda Práxedes

    2016-01-01

    El objetivo principal de esta tesis es estudiar las bases cerebrales de los procesos de búsqueda visual, el desarrollo de la automaticidad a través del entrenamiento, y la relación entre los procesos subyacentes a la búsqueda visual, los modelos teóricos de la atención y la neuroplasticidad. La tarea de búsqueda visual fue utilizada en tres experimentos, recogiendo datos conductuales y de la actividad y conectividad cerebral mediante RMf en población sana. Los resultados señalan las tareas at...

  17. Neural organization and visual processing in the anterior optic tubercle of the honeybee brain.

    Science.gov (United States)

    Mota, Theo; Yamagata, Nobuhiro; Giurfa, Martin; Gronenberg, Wulfila; Sandoz, Jean-Christophe

    2011-08-10

    The honeybee Apis mellifera represents a valuable model for studying the neural segregation and integration of visual information. Vision in honeybees has been extensively studied at the behavioral level and, to a lesser degree, at the physiological level using intracellular electrophysiological recordings of single neurons. However, our knowledge of visual processing in honeybees is still limited by the lack of functional studies of visual processing at the circuit level. Here we contribute to filling this gap by providing a neuroanatomical and neurophysiological characterization at the circuit level of a practically unstudied visual area of the bee brain, the anterior optic tubercle (AOTu). First, we analyzed the internal organization and neuronal connections of the AOTu. Second, we established a novel protocol for performing optophysiological recordings of visual circuit activity in the honeybee brain and studied the responses of AOTu interneurons during stimulation of distinct eye regions. Our neuroanatomical data show an intricate compartmentalization and connectivity of the AOTu, revealing a dorsoventral segregation of the visual input to the AOTu. Light stimuli presented in different parts of the visual field (dorsal, lateral, or ventral) induce distinct patterns of activation in AOTu output interneurons, retaining to some extent the dorsoventral input segregation revealed by our neuroanatomical data. In particular, activity patterns evoked by dorsal and ventral eye stimulation are clearly segregated into distinct AOTu subunits. Our results therefore suggest an involvement of the AOTu in the processing of dorsoventrally segregated visual information in the honeybee brain. PMID:21832175

  18. Sustained Rhythmic Brain Activity Underlies Visual Motion Perception in Zebrafish

    Directory of Open Access Journals (Sweden)

    Verónica Pérez-Schuster

    2016-10-01

    Full Text Available Following moving visual stimuli (conditioning stimuli, CS, many organisms perceive, in the absence of physical stimuli, illusory motion in the opposite direction. This phenomenon is known as the motion aftereffect (MAE. Here, we use MAE as a tool to study the neuronal basis of visual motion perception in zebrafish larvae. Using zebrafish eye movements as an indicator of visual motion perception, we find that larvae perceive MAE. Blocking eye movements using optogenetics during CS presentation did not affect MAE, but tectal ablation significantly weakened it. Using two-photon calcium imaging of behaving GCaMP3 larvae, we find post-stimulation sustained rhythmic activity among direction-selective tectal neurons associated with the perception of MAE. In addition, tectal neurons tuned to the CS direction habituated, but neurons in the retina did not. Finally, a model based on competition between direction-selective neurons reproduced MAE, suggesting a neuronal circuit capable of generating perception of visual motion.

  19. Structural and functional correlates of visual field asymmetry in the human brain by diffusion kurtosis MRI and functional MRI.

    Science.gov (United States)

    O'Connell, Caitlin; Ho, Leon C; Murphy, Matthew C; Conner, Ian P; Wollstein, Gadi; Cham, Rakie; Chan, Kevin C

    2016-11-01

    Human visual performance has been observed to show superiority in localized regions of the visual field across many classes of stimuli. However, the underlying neural mechanisms remain unclear. This study aims to determine whether the visual information processing in the human brain is dependent on the location of stimuli in the visual field and the corresponding neuroarchitecture using blood-oxygenation-level-dependent functional MRI (fMRI) and diffusion kurtosis MRI, respectively, in 15 healthy individuals at 3 T. In fMRI, visual stimulation to the lower hemifield showed stronger brain responses and larger brain activation volumes than the upper hemifield, indicative of the differential sensitivity of the human brain across the visual field. In diffusion kurtosis MRI, the brain regions mapping to the lower visual field showed higher mean kurtosis, but not fractional anisotropy or mean diffusivity compared with the upper visual field. These results suggested the different distributions of microstructural organization across visual field brain representations. There was also a strong positive relationship between diffusion kurtosis and fMRI responses in the lower field brain representations. In summary, this study suggested the structural and functional brain involvements in the asymmetry of visual field responses in humans, and is important to the neurophysiological and psychological understanding of human visual information processing.

  20. How the visual brain encodes and keeps track of time.

    Science.gov (United States)

    Salvioni, Paolo; Murray, Micah M; Kalmbach, Lysiann; Bueti, Domenica

    2013-07-24

    Time is embedded in any sensory experience: the movements of a dance, the rhythm of a piece of music, the words of a speaker are all examples of temporally structured sensory events. In humans, if and how visual cortices perform temporal processing remains unclear. Here we show that both primary visual cortex (V1) and extrastriate area V5/MT are causally involved in encoding and keeping time in memory and that this involvement is independent from low-level visual processing. Most importantly we demonstrate that V1 and V5/MT come into play simultaneously and seem to be functionally linked during interval encoding, whereas they operate serially (V1 followed by V5/MT) and seem to be independent while maintaining temporal information in working memory. These data help to refine our knowledge of the functional properties of human visual cortex, highlighting the contribution and the temporal dynamics of V1 and V5/MT in the processing of the temporal aspects of visual information. PMID:23884947

  1. Brain activity related to integrative processes in visual object recognition

    DEFF Research Database (Denmark)

    Gerlach, Christian; Aaside, C T; Humphreys, G W;

    2002-01-01

    We report evidence from a PET activation study that the inferior occipital gyri (likely to include area V2) and the posterior parts of the fusiform and inferior temporal gyri are involved in the integration of visual elements into perceptual wholes (single objects). Of these areas, the fusiform a...

  2. The nature of consciousness in the visually deprived brain

    DEFF Research Database (Denmark)

    Kupers, Ron; Pietrini, Pietro; Ricciardi, Emiliano;

    2011-01-01

    Vision plays a central role in how we represent and interact with the world around us. The primacy of vision is structurally imbedded in cortical organization as about one-third of the cortical surface in primates is involved in visual processes. Consequently, the loss of vision, either at birth ...

  3. DF's visual brain in action: the role of tactile cues.

    Science.gov (United States)

    Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Byrne, Caitlin M; Goodale, Melvyn A

    2014-03-01

    Patient DF, an extensively-tested woman with visual form agnosia from ventral-stream damage, is able to scale her grip aperture to match a goal object's geometry when reaching out to pick it up, despite being unable to explicitly distinguish amongst objects on the basis of their different geometries. Using evidence from a range of sources, including functional MRI, we have proposed that she does this through a functionally intact visuomotor system housed within the dorsal stream of the posterior parietal lobe. More recently, however, Schenk (2012a). The Journal of Neuroscience, 32(6), 2013-2017; Schenk (2012b). Trends in Cognitive Sciences, 16(5), 258-259. has argued that DF performs well in visually guided grasping, not through spared and functioning visuomotor networks in the dorsal stream, but because haptic feedback about the locations of the edges of the target is available to calibrate her grasps in such tasks, whereas it is not available in standard visual perceptual tasks. We have tested this 'calibration hypothesis' directly, by presenting DF with a grasping task in which the visible width of a target varied from trial to trial while its actual width remained the same. According to the calibration hypothesis, because haptic feedback was completely uninformative, DF should be unable to calibrate her grip aperture in this task. Contrary to this prediction, we found that DF continued to scale her grip aperture to the visual width of the targets and did so well within the range of healthy controls. We also found that DF's inability to distinguish shapes perceptually is not improved by providing haptic feedback. These findings strengthen the notion that DF's spared visuomotor abilities are driven largely by visual feedforward processing of the geometric properties of the target. Crucially, these findings also indicate that simple tactile contact with an object is needed for the visuomotor dorsal stream to be engaged, and accordingly enables DF to execute

  4. Intensity-based registration and combined visualization of multimodal brain images for noninvasive epilepsy surgery planning

    Science.gov (United States)

    Hong, Helen; Shin, Yeong G.

    2003-05-01

    To visualize the brain anatomy, seizure focus location and grid and strip electrode in 3-dimensional space provides improved planning information for focus localization and margin determination pre- and intra-operatively. However given the relatively poor spatial resolution and structural detail of the PET images, it can be difficult to recognize precise anatomic localization of the site of increased activation during seizure. In this paper, we present an intensity-based registration and combined visualization of CT, MR and PET brain images to provide both critical functional information and the structural details.

  5. Visual Learning Alters the Spontaneous Activity of the Resting Human Brain: An fNIRS Study

    OpenAIRE

    Haijing Niu; Hao Li; Li Sun; Yongming Su; Jing Huang; Yan Song

    2014-01-01

    Resting-state functional connectivity (RSFC) has been widely used to investigate spontaneous brain activity that exhibits correlated fluctuations. RSFC has been found to be changed along the developmental course and after learning. Here, we investigated whether and how visual learning modified the resting oxygenated hemoglobin (HbO) functional brain connectivity by using functional near-infrared spectroscopy (fNIRS). We demonstrate that after five days of training on an orientation discrimina...

  6. Steady state visually evoked potentials based Brain computer interface test outside the lab

    OpenAIRE

    Eduardo Francisco Caicedo Bravo; Jaiber Evelio Cardona Aristizábal

    2016-01-01

    Context: Steady State Visually Evoked Potentials (SSVEP) are brain signals which are one of the most promising signals for Brain Computer Interfaces (BCIs) implementation, however, SSVEP based BCI generally are proven in a controlled environment and there are a few tests in demanding conditions.Method: We present a SSVEP based BCI system that was used outside the lab in a noisy environment with distractions, and with the presence of public. For the tests, we showed a maze in a laptop where th...

  7. Invariance of brain-wave representations of simple visual images and their names

    OpenAIRE

    Suppes, Patrick; Han, Bing; Epelboim, Julie; Lu, Zhong-Lin

    1999-01-01

    In two experiments, electric brain waves of 14 subjects were recorded under several different conditions to study the invariance of brain-wave representations of simple patches of colors and simple visual shapes and their names, the words blue, circle, etc. As in our earlier work, the analysis consisted of averaging over trials to create prototypes and test samples, to both of which Fourier transforms were applied, followed by filtering and an inverse transformation to the time domain. A leas...

  8. Timing and sequence of brain activity in top-down control of visual-spatial attention.

    OpenAIRE

    Tineke Grent-'t-Jong; Woldorff, Marty G.

    2007-01-01

    Recent brain imaging studies using functional magnetic resonance imaging (fMRI) have implicated a frontal-parietal network in the top-down control of attention. However, little is known about the timing and sequence of activations within this network. To investigate these timing questions, we used event-related electrical brain potentials (ERPs) and a specially designed visual-spatial attentional-cueing paradigm, which were applied as part of a multi-methodological approach that included a cl...

  9. Time processing in visual cortices: How the visual brain encodes and keeps track of time

    OpenAIRE

    Salvioni P.

    2012-01-01

    Time is embedded in any sensory experience: the movements of a dance, the rhythm of a piece of music, the words of a speaker are all examples of temporally structured sensory events. In humans, if and how visual cortices perform temporal processing remains unclear. Here we show that both primary visual cortex (V1) and extrastriate area V5/MT are causally involved in encoding and keeping time in memory and that this involvement is independent from low-level visual processing. Most importantly ...

  10. Scale-Free Brain Networks Based on the Event-Related Potential during Visual Spatial Attention

    Institute of Scientific and Technical Information of China (English)

    LI Ling; JIN Zhen-Lan

    2011-01-01

    @@ The human brain is thought of as one of the most complex dynamical systems in the universe.The network view of the dynamical system has emerged since the discovery of scale-free networks.Brain functional networks, which represent functional associations among brain regions, are extracted by measuring the temporal correlations from electroencephalogram data.We measure the topological properties of the brain functional network, including degree distribution, average degree, clustering coefficient and the shortest path length, to compare the networks of multi-channel event-related potential activity between visual spatial attention and unattention conditions.It is found that the degree distribution of the brain functional networks under both the conditions is a power law distribution, which reflects a scale-free property.Moreover, the scaling exponent of the attention condition is significantly smaller than that of the unattention condition.However, the degree distribution of equivalent random networks does not follow the power law distribution.In addition, the clustering coefficient of these random networks is smaller than those of brain networks, and the shortest path length of these random networks is large and comparable with those of brain networks.Our results, typical of scale-free networks, indicate that the scaling exponent of brain activity could reflect different cognitive processes.%The human brain is thought of as one of the most complex dynamical systems in the universe. The network view of the dynamical system has emerged since the discovery of scale-free networks. Brain functional networks, which represent functional associations among brain regions, are extracted by measuring the temporal correlations from electroencephalogram data. We measure the topological properties of the brain functional network, including degree distribution, average degree, clustering coefficient and the shortest path length, to compare the networks of multi-channel event

  11. Stereoscopic Three-Dimensional Visualization Applied to Multimodal Brain Images: Clinical Applications and a Functional Connectivity Atlas.

    Directory of Open Access Journals (Sweden)

    Gonzalo M Rojas

    2014-11-01

    Full Text Available Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity.

  12. The Development of Hand-Centered Visual Representations in the Primate Brain: A Computer Modeling Study Using Natural Visual Scenes.

    Science.gov (United States)

    Galeazzi, Juan M; Minini, Loredana; Stringer, Simon M

    2015-01-01

    Neurons that respond to visual targets in a hand-centered frame of reference have been found within various areas of the primate brain. We investigate how hand-centered visual representations may develop in a neural network model of the primate visual system called VisNet, when the model is trained on images of the hand seen against natural visual scenes. The simulations show how such neurons may develop through a biologically plausible process of unsupervised competitive learning and self-organization. In an advance on our previous work, the visual scenes consisted of multiple targets presented simultaneously with respect to the hand. Three experiments are presented. First, VisNet was trained with computerized images consisting of a realistic image of a hand and a variety of natural objects, presented in different textured backgrounds during training. The network was then tested with just one textured object near the hand in order to verify if the output cells were capable of building hand-centered representations with a single localized receptive field. We explain the underlying principles of the statistical decoupling that allows the output cells of the network to develop single localized receptive fields even when the network is trained with multiple objects. In a second simulation we examined how some of the cells with hand-centered receptive fields decreased their shape selectivity and started responding to a localized region of hand-centered space as the number of objects presented in overlapping locations during training increases. Lastly, we explored the same learning principles training the network with natural visual scenes collected by volunteers. These results provide an important step in showing how single, localized, hand-centered receptive fields could emerge under more ecologically realistic visual training conditions.

  13. The development of hand-centred visual representations in the primate brain: a computer modelling study using natural visual scenes.

    Directory of Open Access Journals (Sweden)

    Juan Manuel Galeazzi

    2015-12-01

    Full Text Available Neurons that respond to visual targets in a hand-centred frame of reference have been found within various areas of the primate brain. We investigate how hand-centred visual representations may develop in a neural network model of the primate visual system called VisNet, when the model is trained on images of the hand seen against natural visual scenes. The simulations show how such neurons may develop through a biologically plausible process of unsupervised competitive learning and self-organisation. In an advance on our previous work, the visual scenes consisted of multiple targets presented simultaneously with respect to the hand. Three experiments are presented. First, VisNet was trained with computerized images consisting of a realistic image of a hand and and a variety of natural objects, presented in different textured backgrounds during training. The network was then tested with just one textured object near the hand in order to verify if the output cells were capable of building hand-centered representations with a single localised receptive field. We explain the underlying principles of the statistical decoupling that allows the output cells of the network to develop single localised receptive fields even when the network is trained with multiple objects. In a second simulation we examined how some of the cells with hand-centred receptive fields decreased their shape selectivity and started responding to a localised region of hand-centred space as the number of objects presented in overlapping locations during training increases. Lastly, we explored the same learning principles training the network with natural visual scenes collected by volunteers. These results provide an important step in showing how single, localised, hand-centered receptive fields could emerge under more ecologically realistic visual training conditions.

  14. The Development of Hand-Centered Visual Representations in the Primate Brain: A Computer Modeling Study Using Natural Visual Scenes.

    Science.gov (United States)

    Galeazzi, Juan M; Minini, Loredana; Stringer, Simon M

    2015-01-01

    Neurons that respond to visual targets in a hand-centered frame of reference have been found within various areas of the primate brain. We investigate how hand-centered visual representations may develop in a neural network model of the primate visual system called VisNet, when the model is trained on images of the hand seen against natural visual scenes. The simulations show how such neurons may develop through a biologically plausible process of unsupervised competitive learning and self-organization. In an advance on our previous work, the visual scenes consisted of multiple targets presented simultaneously with respect to the hand. Three experiments are presented. First, VisNet was trained with computerized images consisting of a realistic image of a hand and a variety of natural objects, presented in different textured backgrounds during training. The network was then tested with just one textured object near the hand in order to verify if the output cells were capable of building hand-centered representations with a single localized receptive field. We explain the underlying principles of the statistical decoupling that allows the output cells of the network to develop single localized receptive fields even when the network is trained with multiple objects. In a second simulation we examined how some of the cells with hand-centered receptive fields decreased their shape selectivity and started responding to a localized region of hand-centered space as the number of objects presented in overlapping locations during training increases. Lastly, we explored the same learning principles training the network with natural visual scenes collected by volunteers. These results provide an important step in showing how single, localized, hand-centered receptive fields could emerge under more ecologically realistic visual training conditions. PMID:26696876

  15. Impaired Visual Integration in Children with Traumatic Brain Injury: An Observational Study.

    Directory of Open Access Journals (Sweden)

    Marsh Königs

    Full Text Available Axonal injury after traumatic brain injury (TBI may cause impaired sensory integration. We aim to determine the effects of childhood TBI on visual integration in relation to general neurocognitive functioning.We compared children aged 6-13 diagnosed with TBI (n = 103; M = 1.7 years post-injury to children with traumatic control (TC injury (n = 44. Three TBI severity groups were distinguished: mild TBI without risk factors for complicated TBI (mildRF- TBI, n = 22, mild TBI with ≥1 risk factor (mildRF+ TBI, n = 46 or moderate/severe TBI (n = 35. An experimental paradigm measured speed and accuracy of goal-directed behavior depending on: (1 visual identification; (2 visual localization; or (3 both, measuring visual integration. Group-differences on reaction time (RT or accuracy were tracked down to task strategy, visual processing efficiency and extra-decisional processes (e.g. response execution using diffusion model analysis. General neurocognitive functioning was measured by a Wechsler Intelligence Scale short form.The TBI group had poorer accuracy of visual identification and visual integration than the TC group (Ps ≤ .03; ds ≤ -0.40. Analyses differentiating TBI severity revealed that visual identification accuracy was impaired in the moderate/severe TBI group (P = .05, d = -0.50 and that visual integration accuracy was impaired in the mildRF+ TBI group and moderate/severe TBI group (Ps < .02, ds ≤ -0.56. Diffusion model analyses tracked impaired visual integration accuracy down to lower visual integration efficiency in the mildRF+ TBI group and moderate/severe TBI group (Ps < .001, ds ≤ -0.73. Importantly, intelligence impairments observed in the TBI group (P = .009, d = -0.48 were statistically explained by visual integration efficiency (P = .002.Children with mildRF+ TBI or moderate/severe TBI have impaired visual integration efficiency, which may contribute to poorer general neurocognitive functioning.

  16. Brain-potential analysis of visual word recognition in dyslexics and typically reading children

    NARCIS (Netherlands)

    G. Fraga González; G. Žarić; J. Tijms; M. Bonte; L. Blomert; M.W. van der Molen

    2014-01-01

    The specialization of visual brain areas for fast processing of printed words plays an important role in the acquisition of reading skills. Dysregulation of these areas may be among the deficits underlying developmental dyslexia. The present study examines the specificity of word activation in dysle

  17. Interaction of brain areas of visual and vestibular simultaneous activity with fMRI.

    Science.gov (United States)

    Della-Justina, Hellen M; Gamba, Humberto R; Lukasova, Katerina; Nucci-da-Silva, Mariana P; Winkler, Anderson M; Amaro, Edson

    2015-01-01

    Static body equilibrium is an essential requisite for human daily life. It is known that visual and vestibular systems must work together to support equilibrium. However, the relationship between these two systems is not fully understood. In this work, we present the results of a study which identify the interaction of brain areas that are involved with concurrent visual and vestibular inputs. The visual and the vestibular systems were individually and simultaneously stimulated, using flickering checkerboard (without movement stimulus) and galvanic current, during experiments of functional magnetic resonance imaging. Twenty-four right-handed and non-symptomatic subjects participated in this study. Single visual stimulation shows positive blood-oxygen-level-dependent (BOLD) responses (PBR) in the primary and associative visual cortices. Single vestibular stimulation shows PBR in the parieto-insular vestibular cortex, inferior parietal lobe, superior temporal gyrus, precentral gyrus and lobules V and VI of the cerebellar hemisphere. Simultaneous stimulation shows PBR in the middle and inferior frontal gyri and in the precentral gyrus. Vestibular- and somatosensory-related areas show negative BOLD responses (NBR) during simultaneous stimulation. NBR areas were also observed in the calcarine gyrus, lingual gyrus, cuneus and precuneus during simultaneous and single visual stimulations. For static visual and galvanic vestibular simultaneous stimulation, the reciprocal inhibitory visual-vestibular interaction pattern is observed in our results. The experimental results revealed interactions in frontal areas during concurrent visual-vestibular stimuli, which are affected by intermodal association areas in occipital, parietal, and temporal lobes. PMID:25300959

  18. Interaction of brain areas of visual and vestibular simultaneous activity with fMRI.

    Science.gov (United States)

    Della-Justina, Hellen M; Gamba, Humberto R; Lukasova, Katerina; Nucci-da-Silva, Mariana P; Winkler, Anderson M; Amaro, Edson

    2015-01-01

    Static body equilibrium is an essential requisite for human daily life. It is known that visual and vestibular systems must work together to support equilibrium. However, the relationship between these two systems is not fully understood. In this work, we present the results of a study which identify the interaction of brain areas that are involved with concurrent visual and vestibular inputs. The visual and the vestibular systems were individually and simultaneously stimulated, using flickering checkerboard (without movement stimulus) and galvanic current, during experiments of functional magnetic resonance imaging. Twenty-four right-handed and non-symptomatic subjects participated in this study. Single visual stimulation shows positive blood-oxygen-level-dependent (BOLD) responses (PBR) in the primary and associative visual cortices. Single vestibular stimulation shows PBR in the parieto-insular vestibular cortex, inferior parietal lobe, superior temporal gyrus, precentral gyrus and lobules V and VI of the cerebellar hemisphere. Simultaneous stimulation shows PBR in the middle and inferior frontal gyri and in the precentral gyrus. Vestibular- and somatosensory-related areas show negative BOLD responses (NBR) during simultaneous stimulation. NBR areas were also observed in the calcarine gyrus, lingual gyrus, cuneus and precuneus during simultaneous and single visual stimulations. For static visual and galvanic vestibular simultaneous stimulation, the reciprocal inhibitory visual-vestibular interaction pattern is observed in our results. The experimental results revealed interactions in frontal areas during concurrent visual-vestibular stimuli, which are affected by intermodal association areas in occipital, parietal, and temporal lobes.

  19. Brain-potential analysis of visual word recognition in dyslexics and typically reading children

    Directory of Open Access Journals (Sweden)

    Gorka eFraga González

    2014-06-01

    Full Text Available The specialization of visual brain areas for fast processing of printed words plays an important role in the acquisition of reading skills. Dysregulation of these areas may be among the deficits underlying developmental dyslexia. The present study examines the specificity of word activation in dyslexic children in 3rd grade by comparing early components of brain potentials elicited by visually presented words vs. strings of meaningless letter-like symbols. Results showed a more pronounced N1 component for words compared to symbols for both groups. The dyslexic group revealed larger left-lateralized, word-specific N1 responses than the typically reading group. Furthermore, positive correlations between N1 amplitudes and reading fluency were found in the dyslexic group. Our results support the notion of N1 as a sensitive index of visual word processing involved in reading fluency.

  20. The Visual Brain, Perception, and Depiction of Animals in Rock Art

    Directory of Open Access Journals (Sweden)

    Derek Hodgson

    2013-01-01

    Full Text Available Several aspects of the depiction of animals in rock art can be explained by certain perceptual correlates relating to the visual brain and evolutionary factors. Recent evidence from neuroscience and the visual brain not only corroborates this claim but provides important new findings that can help delineate which graphic features relate to biological/genetic criteria. In addition to highlighting how the insights from visual science and evolutionary studies can promote a greater understanding of the depictive strategies employed to portray animals, this paper will also explore ways in which the findings from these disciplines can be assimilated with semiotics that provide novel insights into the preference for depicting animals in a particular format over an extended period. The emphasis throughout is placed on dual-inheritance theory where culture and evolutionary determinants are seen as complementary.

  1. Contralateral and ipsilateral disorders of visual attention in patients with unilateral brain damage.

    Science.gov (United States)

    Gainotti, G; Giustolisi, L; Nocentini, U

    1990-05-01

    To explain the prevalence of unilateral spatial neglect in patients with right brain damage, Heilman et al have suggested that the attentional neurons of the right parietal lobe might have bilateral receptive fields, whereas the homologous cells of the left hemisphere would have strictly contralateral receptive fields. One implication of this theory is that patients with right brain damage should show a prevalence of disorders of visual attention not only in the half space contralateral to the damaged hemisphere, but also in the ipsilateral one. To check this theory, 50 control subjects, 102 right and 125 left brain-damaged patients were given a drawing completion task in which patients were requested to complete the missing parts of a star, a cube and a house. Omissions of lines lying on the sides of the models contralateral and ipsilateral to the damaged hemisphere were taken separately into account. Results did not confirm the hypothesis, since right brain-damaged patients failed to complete the contralateral sides of the models much more frequently than patients with left brain injury, but no difference was found between the two hemispheric groups when ipsilateral disorders of visual attention were taken into account. Furthermore, no correlation was found between omissions of lines lying on the sides of the models contralateral and ipsilateral to the damaged hemisphere. This finding suggests that contralateral and ipsilateral disorders of visual attention are not due to the same mechanism in right brain-damaged patients. The alternative hypothesis viewing ipsilateral disorders as resulting from a widespread lowering of general attention (and only contralateral neglect reflecting a specific disorder of visual attention) was supported by results obtained on a verbal memory test, used to evaluate the general cognitive and attention level of the patients. Patients with clear-cut ipislateral inattention obtained very low scores on this test, whereas patients with

  2. Hemispheric Asymmetry of Visual Scene Processing in the Human Brain: Evidence from Repetition Priming and Intrinsic Activity

    OpenAIRE

    Stevens, W. Dale; Kahn, Itamar; Wig, Gagan S.; Schacter, Daniel L.

    2011-01-01

    Asymmetrical specialization of cognitive processes across the cerebral hemispheres is a hallmark of healthy brain development and an important evolutionary trait underlying higher cognition in humans. While previous research, including studies of priming, divided visual field presentation, and split-brain patients, demonstrates a general pattern of right/left asymmetry of form-specific versus form-abstract visual processing, little is known about brain organization underlying this dissociatio...

  3. Scale-Free Brain Networks Based on the Event-Related Potential during Visual Spatial Attention

    Science.gov (United States)

    Li, Ling; Jin, Zhen-Lan

    2011-04-01

    The human brain is thought of as one of the most complex dynamical systems in the universe. The network view of the dynamical system has emerged since the discovery of scale-free networks. Brain functional networks, which represent functional associations among brain regions, are extracted by measuring the temporal correlations from electroencephalogram data. We measure the topological properties of the brain functional network, including degree distribution, average degree, clustering coefficient and the shortest path length, to compare the networks of multi-channel event-related potential activity between visual spatial attention and unattention conditions. It is found that the degree distribution of the brain functional networks under both the conditions is a power law distribution, which reflects a scale-free property. Moreover, the scaling exponent of the attention condition is significantly smaller than that of the unattention condition. However, the degree distribution of equivalent random networks does not follow the power law distribution. In addition, the clustering coefficient of these random networks is smaller than those of brain networks, and the shortest path length of these random networks is large and comparable with those of brain networks. Our results, typical of scale-free networks, indicate that the scaling exponent of brain activity could reflect different cognitive processes.

  4. Brain-computer interface based on generation of visual images.

    Directory of Open Access Journals (Sweden)

    Pavel Bobrov

    Full Text Available This paper examines the task of recognizing EEG patterns that correspond to performing three mental tasks: relaxation and imagining of two types of pictures: faces and houses. The experiments were performed using two EEG headsets: BrainProducts ActiCap and Emotiv EPOC. The Emotiv headset becomes widely used in consumer BCI application allowing for conducting large-scale EEG experiments in the future. Since classification accuracy significantly exceeded the level of random classification during the first three days of the experiment with EPOC headset, a control experiment was performed on the fourth day using ActiCap. The control experiment has shown that utilization of high-quality research equipment can enhance classification accuracy (up to 68% in some subjects and that the accuracy is independent of the presence of EEG artifacts related to blinking and eye movement. This study also shows that computationally-inexpensive bayesian classifier based on covariance matrix analysis yields similar classification accuracy in this problem as a more sophisticated Multi-class Common Spatial Patterns (MCSP classifier.

  5. Brain activity associated with translation from a visual to a symbolic representation in algebra and geometry.

    Science.gov (United States)

    Leikin, Mark; Waisman, Ilana; Shaul, Shelley; Leikin, Roza

    2014-03-01

    This paper presents a small part of a larger interdisciplinary study that investigates brain activity (using event related potential methodology) of male adolescents when solving mathematical problems of different types. The study design links mathematics education research with neurocognitive studies. In this paper we performed a comparative analysis of brain activity associated with the translation from visual to symbolic representations of mathematical objects in algebra and geometry. Algebraic tasks require translation from graphical to symbolic representation of a function, whereas tasks in geometry require translation from a drawing of a geometric figure to a symbolic representation of its property. The findings demonstrate that electrical activity associated with the performance of geometrical tasks is stronger than that associated with solving algebraic tasks. Additionally, we found different scalp topography of the brain activity associated with algebraic and geometric tasks. Based on these results, we argue that problem solving in algebra and geometry is associated with different patterns of brain activity.

  6. 3D Data Mapping and Real-Time Experiment Control and Visualization in Brain Slices.

    Science.gov (United States)

    Navarro, Marco A; Hibbard, Jaime V K; Miller, Michael E; Nivin, Tyler W; Milescu, Lorin S

    2015-10-20

    Here, we propose two basic concepts that can streamline electrophysiology and imaging experiments in brain slices and enhance data collection and analysis. The first idea is to interface the experiment with a software environment that provides a 3D scene viewer in which the experimental rig, the brain slice, and the recorded data are represented to scale. Within the 3D scene viewer, the user can visualize a live image of the sample and 3D renderings of the recording electrodes with real-time position feedback. Furthermore, the user can control the instruments and visualize their status in real time. The second idea is to integrate multiple types of experimental data into a spatial and temporal map of the brain slice. These data may include low-magnification maps of the entire brain slice, for spatial context, or any other type of high-resolution structural and functional image, together with time-resolved electrical and optical signals. The entire data collection can be visualized within the 3D scene viewer. These concepts can be applied to any other type of experiment in which high-resolution data are recorded within a larger sample at different spatial and temporal coordinates. PMID:26488641

  7. 3D Data Mapping and Real-Time Experiment Control and Visualization in Brain Slices.

    Science.gov (United States)

    Navarro, Marco A; Hibbard, Jaime V K; Miller, Michael E; Nivin, Tyler W; Milescu, Lorin S

    2015-10-20

    Here, we propose two basic concepts that can streamline electrophysiology and imaging experiments in brain slices and enhance data collection and analysis. The first idea is to interface the experiment with a software environment that provides a 3D scene viewer in which the experimental rig, the brain slice, and the recorded data are represented to scale. Within the 3D scene viewer, the user can visualize a live image of the sample and 3D renderings of the recording electrodes with real-time position feedback. Furthermore, the user can control the instruments and visualize their status in real time. The second idea is to integrate multiple types of experimental data into a spatial and temporal map of the brain slice. These data may include low-magnification maps of the entire brain slice, for spatial context, or any other type of high-resolution structural and functional image, together with time-resolved electrical and optical signals. The entire data collection can be visualized within the 3D scene viewer. These concepts can be applied to any other type of experiment in which high-resolution data are recorded within a larger sample at different spatial and temporal coordinates.

  8. Functional divisions for visual processing in the central brain of flying Drosophila

    Science.gov (United States)

    Weir, Peter T.; Dickinson, Michael H.

    2015-01-01

    Although anatomy is often the first step in assigning functions to neural structures, it is not always clear whether architecturally distinct regions of the brain correspond to operational units. Whereas neuroarchitecture remains relatively static, functional connectivity may change almost instantaneously according to behavioral context. We imaged panneuronal responses to visual stimuli in a highly conserved central brain region in the fruit fly, Drosophila, during flight. In one substructure, the fan-shaped body, automated analysis revealed three layers that were unresponsive in quiescent flies but became responsive to visual stimuli when the animal was flying. The responses of these regions to a broad suite of visual stimuli suggest that they are involved in the regulation of flight heading. To identify the cell types that underlie these responses, we imaged activity in sets of genetically defined neurons with arborizations in the targeted layers. The responses of this collection during flight also segregated into three sets, confirming the existence of three layers, and they collectively accounted for the panneuronal activity. Our results provide an atlas of flight-gated visual responses in a central brain circuit. PMID:26324910

  9. Welding of Prosthetic Alloys

    Directory of Open Access Journals (Sweden)

    Wojciechowska M.

    2015-04-01

    Full Text Available This paper presents the techniques of joining metal denture elements, used in prosthetic dentistry: the traditional soldering technique with a gas burner and a new technique of welding with a laser beam; the aim of the study was to make a comparative assessment of the quality of the joints in view of the possibility of applying them in prosthetic structures. Fractographic examinations were conducted along with tensile strength and impact strength tests, and the quality of the joints was assessed compared to the solid metal. The experiments have shown that the metal elements used to make dentures, joined by the technique which employs a laser beam, have better strength properties than those achieved with a gas burner.

  10. How art changes your brain: differential effects of visual art production and cognitive art evaluation on functional brain connectivity.

    Directory of Open Access Journals (Sweden)

    Anne Bolwerk

    Full Text Available Visual art represents a powerful resource for mental and physical well-being. However, little is known about the underlying effects at a neural level. A critical question is whether visual art production and cognitive art evaluation may have different effects on the functional interplay of the brain's default mode network (DMN. We used fMRI to investigate the DMN of a non-clinical sample of 28 post-retirement adults (63.71 years ±3.52 SD before (T0 and after (T1 weekly participation in two different 10-week-long art interventions. Participants were randomly assigned to groups stratified by gender and age. In the visual art production group 14 participants actively produced art in an art class. In the cognitive art evaluation group 14 participants cognitively evaluated artwork at a museum. The DMN of both groups was identified by using a seed voxel correlation analysis (SCA in the posterior cingulated cortex (PCC/preCUN. An analysis of covariance (ANCOVA was employed to relate fMRI data to psychological resilience which was measured with the brief German counterpart of the Resilience Scale (RS-11. We observed that the visual art production group showed greater spatial improvement in functional connectivity of PCC/preCUN to the frontal and parietal cortices from T0 to T1 than the cognitive art evaluation group. Moreover, the functional connectivity in the visual art production group was related to psychological resilience (i.e., stress resistance at T1. Our findings are the first to demonstrate the neural effects of visual art production on psychological resilience in adulthood.

  11. Magnets in prosthetic dentistry.

    Science.gov (United States)

    Riley, M A; Walmsley, A D; Harris, I R

    2001-08-01

    Magnetic retention is a popular method of attaching removable prostheses to either retained roots or osseointegrated implants. This review chronicles the development of magnets in dentistry and summarizes future research in their use. The literature was researched by using the Science Citation Index and Compendex Web from 1981 to 2000. Articles published before 1981 were hand researched from citations in other publications. Articles that discussed the use of magnets in relation to prosthetic dentistry were selected.

  12. Left Brain vs. Right Brain: Findings on Visual Spatial Capacities and the Functional Neurology of Giftedness

    Science.gov (United States)

    Kalbfleisch, M. Layne; Gillmarten, Charles

    2013-01-01

    As neuroimaging technologies increase their sensitivity to assess the function of the human brain and results from these studies draw the attention of educators, it becomes paramount to identify misconceptions about what these data illustrate and how these findings might be applied to educational contexts. Some of these "neuromyths" have…

  13. From head to toe: Evidence for selective brain activation reflecting visual perception of whole individuals

    OpenAIRE

    Laura eSchmalzl; Regine eZopf; Williams, Mark A.

    2012-01-01

    Our ability to recognize other people’s faces and bodies is crucial for our social interactions. Previous neuroimaging studies have repeatedly demonstrated the existence of brain areas that selectively respond to visually presented faces and bodies. In daily life, however, we see "whole" people and not just isolated faces and bodies, and the question remains of how information from these two categories of stimuli is integrated at a neural level. Are faces and bodies merely processed...

  14. Brain responses to repeated visual experience among low and high sensation seekers: role of boredom susceptibility

    OpenAIRE

    Jiang, Yang; Lianekhammy, Joann; Lawson, Adam; Guo, Chunyan; ynam, Donald; Joseph, Jane E.; Gold, Brian T.; Kelly, Thomas H.

    2009-01-01

    To better understand individual differences in sensation seeking and its components, including boredom susceptibility and experience seeking, we examined brain responses of high and low sensation seekers during repeated visual experience. Individuals scoring in the top and bottom quartiles from a college-aged population on the Brief Sensation-Seeking Scale (BSSS) participated in an event-related potentials (ERPs) experiment. Line drawings of common objects were randomly intermixed and present...

  15. Perceptual moments of conscious visual experience inferred from oscillatory brain activity

    OpenAIRE

    Smith, Marie L.; Gosselin, Frédéric; Philippe G Schyns

    2006-01-01

    Transient periods of synchronized oscillating neuronal discharges in the brain have been proposed to support the discrete perceptual moments underlying conscious visual experience. However, the information content of these perceptual moments remains a critical challenge to the understanding of consciousness. We uncovered this information content in four observers who consciously perceived each interpretation of the ambiguous Dali painting Slave Market with the Disappearing Bust of Voltaire. F...

  16. Dissociable circuits for visual shape learning in the young and aging human brain

    OpenAIRE

    Mayhew, Stephen D.; Kourtzi, Zoe

    2013-01-01

    Recognizing objects in cluttered scenes is vital for successful interactions in our complex environments. Learning is known to play a key role in facilitating performance in a wide range of perceptual skills not only in young but also older adults. However, the neural mechanisms that support our ability to improve visual form recognition with training in older age remain largely unknown. Here, we combine behavioral and fMRI measurements to identify the brain circuits involved in the learning ...

  17. Development of visual motion perception for prospective control: Brain and behavioural studies in infants

    OpenAIRE

    Seth B. Agyei; Ruud eVan der Weel; van der Meer, Audrey L. H.

    2016-01-01

    During infancy, smart perceptual mechanisms develop allowing infants to judge time-space motion dynamics more efficiently with age and locomotor experience. This emerging capacity may be vital to enable preparedness for upcoming events and to be able to navigate in a changing environment. Little is known about brain changes that support the development of prospective control and about processes, such as preterm birth, that may compromise it. As a function of perception of visual motion, this ...

  18. Local Versus Global Effects of Isoflurane Anesthesia on Visual Processing in the Fly Brain.

    Science.gov (United States)

    Cohen, Dror; Zalucki, Oressia H; van Swinderen, Bruno; Tsuchiya, Naotsugu

    2016-01-01

    What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly (Drosophila melanogaster). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli ('frequency tags') allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain. PMID:27517084

  19. Brain dynamic mechanisms on the visual attention scale with Chinese characters cues

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The temporal dynamics in brain evoked by the scale of visual attention with the cues of Chinese characters were studied by recording event-related potentials (ERPs). With the fixed orientation of visual attention, 14 healthy young participants performed a search task in which the search array was preceded by Chinese characters cues, "大, 中, 小" (large, medium, small). 128 channels scalp ERPs were recorded to study the role of visual attention scale played in the visual spatial attention. The results showed that there was no significant difference in the ERP components evoked by the three Chinese characters cues except the inferoposterior N2 latency. The targets evoked P2, N2 amplitudes and latency have significant differences with the different cues of large, middle and small, while P1 and N1 components had no significant difference. The results suggested that the processing of scale of visual attention was mainly concerned with P2, N2 components, while the P1, N1 components were mainly related with the processing of visual orientation information.

  20. Brain SPECT in mesial temporal lobe epilepsy: comparison between visual analysis and SPM (Statistical Parametric Mapping)

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Barbara Juarez; Ramos, Celso Dario; Santos, Allan Oliveira dos; Lima, Mariana da Cunha Lopes de; Camargo, Edwaldo Eduardo; Etchebehere, Elba Cristina Sa de Camargo, E-mail: juarezbarbara@hotmail.co [State University of Campinas (UNICAMP), SP (Brazil). School of Medical Sciences. Dept. of Radiology; Min, Li Li; Cendes, Fernando [State University of Campinas (UNICAMP), SP (Brazil). School of Medical Sciences. Dept. of Neurology

    2010-04-15

    Objective: to compare the accuracy of SPM and visual analysis of brain SPECT in patients with mesial temporal lobe epilepsy (MTLE). Method: interictal and ictal SPECTs of 22 patients with MTLE were performed. Visual analysis were performed in interictal (VISUAL(inter)) and ictal (VISUAL(ictal/inter)) studies. SPM analysis consisted of comparing interictal (SPM(inter)) and ictal SPECTs (SPM(ictal)) of each patient to control group and by comparing perfusion of temporal lobes in ictal and interictal studies among themselves (SPM(ictal/inter)). Results: for detection of the epileptogenic focus, the sensitivities were as follows: VISUAL(inter)=68%; VISUAL(ictal/inter)=100%; SPM(inter)=45%; SPM(ictal)=64% and SPM(ictal/inter)=77%. SPM was able to detect more areas of hyperperfusion and hypoperfusion. Conclusion: SPM did not improve the sensitivity to detect epileptogenic focus. However, SPM detected different regions of hypoperfusion and hyperperfusion and is therefore a helpful tool for better understand pathophysiology of seizures in MTLE. (author)

  1. A Multi-facetted Visual Analytics Tool for Exploratory Analysis of Human Brain and Function Datasets.

    Science.gov (United States)

    Angulo, Diego A; Schneider, Cyril; Oliver, James H; Charpak, Nathalie; Hernandez, Jose T

    2016-01-01

    Brain research typically requires large amounts of data from different sources, and often of different nature. The use of different software tools adapted to the nature of each data source can make research work cumbersome and time consuming. It follows that data is not often used to its fullest potential thus limiting exploratory analysis. This paper presents an ancillary software tool called BRAVIZ that integrates interactive visualization with real-time statistical analyses, facilitating access to multi-facetted neuroscience data and automating many cumbersome and error-prone tasks required to explore such data. Rather than relying on abstract numerical indicators, BRAVIZ emphasizes brain images as the main object of the analysis process of individuals or groups. BRAVIZ facilitates exploration of trends or relationships to gain an integrated view of the phenomena studied, thus motivating discovery of new hypotheses. A case study is presented that incorporates brain structure and function outcomes together with different types of clinical data.

  2. Toward high performance, weakly invasive brain computer interfaces using selective visual attention.

    Science.gov (United States)

    Rotermund, David; Ernst, Udo A; Mandon, Sunita; Taylor, Katja; Smiyukha, Yulia; Kreiter, Andreas K; Pawelzik, Klaus R

    2013-04-01

    Brain-computer interfaces have been proposed as a solution for paralyzed persons to communicate and interact with their environment. However, the neural signals used for controlling such prostheses are often noisy and unreliable, resulting in a low performance of real-world applications. Here we propose neural signatures of selective visual attention in epidural recordings as a fast, reliable, and high-performance control signal for brain prostheses. We recorded epidural field potentials with chronically implanted electrode arrays from two macaque monkeys engaged in a shape-tracking task. For single trials, we classified the direction of attention to one of two visual stimuli based on spectral amplitude, coherence, and phase difference in time windows fixed relative to stimulus onset. Classification performances reached up to 99.9%, and the information about attentional states could be transferred at rates exceeding 580 bits/min. Good classification can already be achieved in time windows as short as 200 ms. The classification performance changed dynamically over the trial and modulated with the task's varying demands for attention. For all three signal features, the information about the direction of attention was contained in the γ-band. The most informative feature was spectral amplitude. Together, these findings establish a novel paradigm for constructing brain prostheses as, for example, virtual spelling boards, promising a major gain in performance and robustness for human brain-computer interfaces.

  3. Visualization of brain tumor using I-123-vascular endothelial growth factor scintigraphy

    International Nuclear Information System (INIS)

    Full text: Aim:Vascular endothelial growth factor (VEGF) is a major angiogenic factor. VEGF receptors have been shown to be overexpressed in a variety of tumor vessels including glioblastoma, which may provide the molecular basis for a successful use of radiolabeled VEGF as tumor angiogenesis tracer. In this study we investigated the usefulness of 1231- VEGF as angiogenesis tracer for imaging brain tumors in vivo. Methods and Results: SPECT examinations were performed 30 minutes and 18 hours after intravenous application of 1231-VEGF (191 ± 15 MBq) in 20 patients with brain tumor. Glioblastomas were visualized in 7 of 8 patients (88 %) shortly after application of 1231- VEGF and were still clearly shown 18 hours post injection. Negative scan results were obtained in one patient with a small glioblastoma size (diameter <2.0 cm) and in 3 patients with benign glioma as well as in 5 patients with glioblastoma after receiving radiotherapy and for chemotherapy. Weak positive results were obtained in 3 patients with brain lymphoma or other tumors. No side effects were observed in patients after administration of 1231- VEG F. Conclusion: Our results indicate that 1231- VEGF scintigraphy may be useful to visualize the angiogenesis of brain tumors and to monitor the treatment response.

  4. Thermoplastics for prosthetic applications.

    Science.gov (United States)

    Lawrence, R B; Davies, R M

    1981-10-01

    The rapid and accurate thermoforming of plastics for prosthetic applications has been the subject of considerable research and development by the Bioengineering Centre. This paper outlines the progress in the general concepts that have been effected to date. The original below knee (B/K) socket vacuum forming technique has been extended to above knee (A/K) and supracondylar cases, and there have been developments in rotational casting technology. The work is necessarily based on a sound understanding of the properties of the materials concerned and of the associated manufacturing processes. The contribution of the Bioengineering Centre is outlined together with summaries of collaborative work carried out with other organizations.

  5. Intrinsic activity in the fly brain gates visual information during behavioral choices.

    Directory of Open Access Journals (Sweden)

    Shiming Tang

    Full Text Available The small insect brain is often described as an input/output system that executes reflex-like behaviors. It can also initiate neural activity and behaviors intrinsically, seen as spontaneous behaviors, different arousal states and sleep. However, less is known about how intrinsic activity in neural circuits affects sensory information processing in the insect brain and variability in behavior. Here, by simultaneously monitoring Drosophila's behavioral choices and brain activity in a flight simulator system, we identify intrinsic activity that is associated with the act of selecting between visual stimuli. We recorded neural output (multiunit action potentials and local field potentials in the left and right optic lobes of a tethered flying Drosophila, while its attempts to follow visual motion (yaw torque were measured by a torque meter. We show that when facing competing motion stimuli on its left and right, Drosophila typically generate large torque responses that flip from side to side. The delayed onset (0.1-1 s and spontaneous switch-like dynamics of these responses, and the fact that the flies sometimes oppose the stimuli by flying straight, make this behavior different from the classic steering reflexes. Drosophila, thus, seem to choose one stimulus at a time and attempt to rotate toward its direction. With this behavior, the neural output of the optic lobes alternates; being augmented on the side chosen for body rotation and suppressed on the opposite side, even though the visual input to the fly eyes stays the same. Thus, the flow of information from the fly eyes is gated intrinsically. Such modulation can be noise-induced or intentional; with one possibility being that the fly brain highlights chosen information while ignoring the irrelevant, similar to what we know to occur in higher animals.

  6. Broad-Band Visually Evoked Potentials: Re(convolution in Brain-Computer Interfacing.

    Directory of Open Access Journals (Sweden)

    Jordy Thielen

    Full Text Available Brain-Computer Interfaces (BCIs allow users to control devices and communicate by using brain activity only. BCIs based on broad-band visual stimulation can outperform BCIs using other stimulation paradigms. Visual stimulation with pseudo-random bit-sequences evokes specific Broad-Band Visually Evoked Potentials (BBVEPs that can be reliably used in BCI for high-speed communication in speller applications. In this study, we report a novel paradigm for a BBVEP-based BCI that utilizes a generative framework to predict responses to broad-band stimulation sequences. In this study we designed a BBVEP-based BCI using modulated Gold codes to mark cells in a visual speller BCI. We defined a linear generative model that decomposes full responses into overlapping single-flash responses. These single-flash responses are used to predict responses to novel stimulation sequences, which in turn serve as templates for classification. The linear generative model explains on average 50% and up to 66% of the variance of responses to both seen and unseen sequences. In an online experiment, 12 participants tested a 6 × 6 matrix speller BCI. On average, an online accuracy of 86% was reached with trial lengths of 3.21 seconds. This corresponds to an Information Transfer Rate of 48 bits per minute (approximately 9 symbols per minute. This study indicates the potential to model and predict responses to broad-band stimulation. These predicted responses are proven to be well-suited as templates for a BBVEP-based BCI, thereby enabling communication and control by brain activity only.

  7. A Gaze Independent Brain-Computer Interface Based on Visual Stimulation through Closed Eyelids

    Science.gov (United States)

    Hwang, Han-Jeong; Ferreria, Valeria Y.; Ulrich, Daniel; Kilic, Tayfun; Chatziliadis, Xenofon; Blankertz, Benjamin; Treder, Matthias

    2015-10-01

    A classical brain-computer interface (BCI) based on visual event-related potentials (ERPs) is of limited application value for paralyzed patients with severe oculomotor impairments. In this study, we introduce a novel gaze independent BCI paradigm that can be potentially used for such end-users because visual stimuli are administered on closed eyelids. The paradigm involved verbally presented questions with 3 possible answers. Online BCI experiments were conducted with twelve healthy subjects, where they selected one option by attending to one of three different visual stimuli. It was confirmed that typical cognitive ERPs can be evidently modulated by the attention of a target stimulus in eyes-closed and gaze independent condition, and further classified with high accuracy during online operation (74.58% ± 17.85 s.d.; chance level 33.33%), demonstrating the effectiveness of the proposed novel visual ERP paradigm. Also, stimulus-specific eye movements observed during stimulation were verified as reflex responses to light stimuli, and they did not contribute to classification. To the best of our knowledge, this study is the first to show the possibility of using a gaze independent visual ERP paradigm in an eyes-closed condition, thereby providing another communication option for severely locked-in patients suffering from complex ocular dysfunctions.

  8. Connecting art and the brain: an artist’s perspective on visual indeterminacy

    Directory of Open Access Journals (Sweden)

    Robert ePepperell

    2011-08-01

    Full Text Available In this article I will discuss the intersection between art and neuroscience from the perspective of a practicing artist. I have collaborated on several scientific studies into the effects of art on the brain and behaviour, looking in particular at the phenomenon of ‘visual indeterminacy’. This is a perceptual state in which subjects fail to recognise objects from visual cues. I will look at the background to this phenomenon, and show how various artists have exploited its effect through the history of art. My own attempts to create indeterminate images will be discussed, including some of the technical problems I faced in trying to manipulate the viewer’s perceptual state through paintings. Visual indeterminacy is not widely studied in neuroscience, although references to it can be found in the literature on visual agnosia and object recognition. I will briefly review some of this work and show how my attempts to understand the science behind visual indeterminacy led me to collaborate with psychophysicists and neuroscientists. After reviewing this work, I will discuss the conclusions I have drawn from its findings and consider the problem of how best to integrate neuroscientific methods with artistic knowledge to create truly interdisciplinary approach.

  9. Deep Brain Stimulation of the Pedunculopontine Tegmental Nucleus (PPN) Influences Visual Contrast Sensitivity in Human Observers

    Science.gov (United States)

    Strumpf, Hendrik; Noesselt, Toemme; Schoenfeld, Mircea Ariel; Voges, Jürgen; Panther, Patricia; Kaufmann, Joern; Heinze, Hans-Jochen; Hopf, Jens-Max

    2016-01-01

    The parapontine nucleus of the thalamus (PPN) is a neuromodulatory midbrain structure with widespread connectivity to cortical and subcortical motor structures, as well as the spinal cord. The PPN also projects to the thalamus, including visual relay nuclei like the LGN and the pulvinar. Moreover, there is intense connectivity with sensory structures of the tegmentum in particular with the superior colliculus (SC). Given the existence and abundance of projections to visual sensory structures, it is likely that activity in the PPN has some modulatory influence on visual sensory selection. Here we address this possibility by measuring the visual discrimination performance (luminance contrast thresholds) in a group of patients with Parkinson’s Disease (PD) treated with deep-brain stimulation (DBS) of the PPN to control gait and postural motor deficits. In each patient we measured the luminance-contrast threshold of being able to discriminate an orientation-target (Gabor-grating) as a function of stimulation frequency (high 60Hz, low 8/10, no stimulation). Thresholds were determined using a standard staircase-protocol that is based on parameter estimation by sequential testing (PEST). We observed that under low frequency stimulation thresholds increased relative to no and high frequency stimulation in five out of six patients, suggesting that DBS of the PPN has a frequency-dependent impact on visual selection processes at a rather elementary perceptual level. PMID:27167979

  10. Brain activation profiles during kinesthetic and visual imagery: An fMRI study.

    Science.gov (United States)

    Kilintari, Marina; Narayana, Shalini; Babajani-Feremi, Abbas; Rezaie, Roozbeh; Papanicolaou, Andrew C

    2016-09-01

    The aim of this study was to identify brain regions involved in motor imagery and differentiate two alternative strategies in its implementation: imagining a motor act using kinesthetic or visual imagery. Fourteen adults were precisely instructed and trained on how to imagine themselves or others perform a movement sequence, with the aim of promoting kinesthetic and visual imagery, respectively, in the context of an fMRI experiment using block design. We found that neither modality of motor imagery elicits activation of the primary motor cortex and that each of the two modalities involves activation of the premotor area which is also activated during action execution and action observation conditions, as well as of the supplementary motor area. Interestingly, the visual and the posterior cingulate cortices show reduced BOLD signal during both imagery conditions. Our results indicate that the networks of regions activated in kinesthetic and visual imagery of motor sequences show a substantial, while not complete overlap, and that the two forms of motor imagery lead to a differential suppression of visual areas. PMID:27288703

  11. A Brain Computer Interface for Robust Wheelchair Control Application Based on Pseudorandom Code Modulated Visual Evoked Potential

    DEFF Research Database (Denmark)

    Mohebbi, Ali; Engelsholm, Signe K.D.; Puthusserypady, Sadasivan;

    2015-01-01

    In this pilot study, a novel and minimalistic Brain Computer Interface (BCI) based wheelchair control application was developed. The system was based on pseudorandom code modulated Visual Evoked Potentials (c-VEPs). The visual stimuli in the scheme were generated based on the Gold code...

  12. Processing of visual semantic information to concrete words : temporal dynamics and neural mechanisms indicated by event-related brain potentials

    NARCIS (Netherlands)

    van Schie, HT; Wijers, AA; Mars, RB; Benjamins, JS; Stowe, LA; Mars, Ruben

    2005-01-01

    Event-related brain potentials were used to study the retrieval of visual semantic information to concrete words, and to investigate possible structural overlap between visual object working memory and concreteness effects in word processing. Subjects performed an object working memory task that inv

  13. Processing of visual semantic information to concrete words: temporal dynamics and neural mechanisms indicated by event-related brain potentials

    NARCIS (Netherlands)

    Schie, H.T. van; Wijers, A.A.; Mars, R.B.; Benjamins, J.S.; Stowe, L.A.

    2005-01-01

    Event-related brain potentials were used to study the retrieval of visual semantic information to concrete words, and to investigate possible structural overlap between visual object working memory and concreteness effects in word processing. Subjects performed an object working memory task that inv

  14. Asymmetrical Brain Activity Induced by Voluntary Spatial Attention Depends on the Visual Hemifield: A Functional Near-Infrared Spectroscopy Study

    Science.gov (United States)

    Harasawa, Masamitsu; Shioiri, Satoshi

    2011-01-01

    The effect of the visual hemifield to which spatial attention was oriented on the activities of the posterior parietal and occipital visual cortices was examined using functional near-infrared spectroscopy in order to investigate the neural substrates of voluntary visuospatial attention. Our brain imaging data support the theory put forth in a…

  15. Retinal prosthetics, optogenetics, and chemical photoswitches.

    Science.gov (United States)

    Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

    2014-10-15

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream

  16. Trans3D: a free tool for dynamical visualization of EEG activity transmission in the brain.

    Science.gov (United States)

    Blinowski, Grzegorz; Kamiński, Maciej; Wawer, Dariusz

    2014-08-01

    The problem of functional connectivity in the brain is in the focus of attention nowadays, since it is crucial for understanding information processing in the brain. A large repertoire of measures of connectivity have been devised, some of them being capable of estimating time-varying directed connectivity. Hence, there is a need for a dedicated software tool for visualizing the propagation of electrical activity in the brain. To this aim, the Trans3D application was developed. It is an open access tool based on widely available libraries and supporting both Windows XP/Vista/7(™), Linux and Mac environments. Trans3D can create animations of activity propagation between electrodes/sensors, which can be placed by the user on the scalp/cortex of a 3D model of the head. Various interactive graphic functions for manipulating and visualizing components of the 3D model and input data are available. An application of the Trans3D tool has helped to elucidate the dynamics of the phenomena of information processing in motor and cognitive tasks, which otherwise would have been very difficult to observe. Trans3D is available at: http://www.eeg.pl/.

  17. A Case Report of Unilateral Severe Visual Loss Along with Bilateral Optic Disc Cupping Secondary to Metastatic Brain Tumor

    Directory of Open Access Journals (Sweden)

    M Mahdavi

    2006-07-01

    Full Text Available Purpose: To report a case of unilateral severe visual loss and bilateral optic disc cupping secondary to brain metastasis of bronchogenic carcinoma Patient and findings: A 48 year-old woman presented with severe visual loss of left eye without redness or pain or any systemic findings .Clinical findings included decreased visual acuity of left eye to 4 m CF and (+3 positive Marcus-Gunn reflex .There was asymmetric optic disc cupping associated with visual field defect in left eye The neurologic investigations showed a secondary metastatic tumor in the brain from bronchogenic carcinoma. Conclusion: Before making a diagnosis of normal -tension glaucoma in asymmetric optic disc cupping and normal intraocular pressure, ophthalmologists should rule out neurologic defects and brain tumors.

  18. Visual encoding and fixation target selection in free viewing: presaccadic brain potentials

    Science.gov (United States)

    Nikolaev, Andrey R.; Jurica, Peter; Nakatani, Chie; Plomp, Gijs; van Leeuwen, Cees

    2013-01-01

    In scrutinizing a scene, the eyes alternate between fixations and saccades. During a fixation, two component processes can be distinguished: visual encoding and selection of the next fixation target. We aimed to distinguish the neural correlates of these processes in the electrical brain activity prior to a saccade onset. Participants viewed color photographs of natural scenes, in preparation for a change detection task. Then, for each participant and each scene we computed an image heat map, with temperature representing the duration and density of fixations. The temperature difference between the start and end points of saccades was taken as a measure of the expected task-relevance of the information concentrated in specific regions of a scene. Visual encoding was evaluated according to whether subsequent change was correctly detected. Saccades with larger temperature difference were more likely to be followed by correct detection than ones with smaller temperature differences. The amplitude of presaccadic activity over anterior brain areas was larger for correct detection than for detection failure. This difference was observed for short “scrutinizing” but not for long “explorative” saccades, suggesting that presaccadic activity reflects top-down saccade guidance. Thus, successful encoding requires local scanning of scene regions which are expected to be task-relevant. Next, we evaluated fixation target selection. Saccades “moving up” in temperature were preceded by presaccadic activity of higher amplitude than those “moving down”. This finding suggests that presaccadic activity reflects attention deployed to the following fixation location. Our findings illustrate how presaccadic activity can elucidate concurrent brain processes related to the immediate goal of planning the next saccade and the larger-scale goal of constructing a robust representation of the visual scene. PMID:23818877

  19. Visual encoding and fixation target selection in free viewing: presaccadic brain potentials

    Directory of Open Access Journals (Sweden)

    Andrey R Nikolaev

    2013-06-01

    Full Text Available In scrutinizing a scene, the eyes alternate between fixations and saccades. During a fixation, two component processes can be distinguished: visual encoding and selection of the next fixation target. We aimed to distinguish the neural correlates of these processes in the electrical brain activity prior to a saccade onset. Participants viewed color photographs of natural scenes, in preparation for a change detection task. Then, for each participant and each scene we computed an image heat map, with temperature representing the duration and density of fixations. The temperature difference between the start and end points of saccades was taken as a measure of the expected task-relevance of the information concentrated in specific regions of a scene. Visual encoding was evaluated according to whether subsequent change was correctly detected. Saccades with larger temperature difference were more likely to be followed by correct detection than ones with smaller temperature differences. The amplitude of presaccadic activity over anterior brain areas was larger for correct detection than for detection failure. This difference was observed for short scrutinizing but not for long explorative saccades, suggesting that presaccadic activity reflects top-down saccade guidance. Thus, successful encoding requires local scanning of scene regions which are expected to be task-relevant. Next, we evaluated fixation target selection. Saccades moving up in temperature were preceded by presaccadic activity of higher amplitude than those moving down. This finding suggests that presaccadic activity reflects attention deployed to the following fixation location. Our findings illustrate how presaccadic activity can elucidate concurrent brain processes related to the immediate goal of planning the next saccade and the larger-scale goal of constructing a robust representation of the visual scene.

  20. A 3-D visualization method for image-guided brain surgery.

    Science.gov (United States)

    Bourbakis, N G; Awad, M

    2003-01-01

    This paper deals with a 3D methodology for brain tumor image-guided surgery. The methodology is based on development of a visualization process that mimics the human surgeon behavior and decision-making. In particular, it originally constructs a 3D representation of a tumor by using the segmented version of the 2D MRI images. Then it develops an optimal path for the tumor extraction based on minimizing the surgical effort and penetration area. A cost function, incorporated in this process, minimizes the damage surrounding healthy tissues taking into consideration the constraints of a new snake-like surgical tool proposed here. The tumor extraction method presented in this paper is compared with the ordinary method used on brain surgery, which is based on a straight-line based surgical tool. Illustrative examples based on real simulations present the advantages of the 3D methodology proposed here.

  1. The encoding of temporally irregular and regular visual patterns in the human brain.

    Directory of Open Access Journals (Sweden)

    Semir Zeki

    Full Text Available In the work reported here, we set out to study the neural systems that detect predictable temporal patterns and departures from them. We used functional magnetic resonance imaging (fMRI to locate activity in the brains of subjects when they viewed temporally regular and irregular patterns produced by letters, numbers, colors and luminance. Activity induced by irregular sequences was located within dorsolateral prefrontal cortex, including an area that was responsive to irregular patterns regardless of the type of visual stimuli producing them. Conversely, temporally regular arrangements resulted in activity in the right frontal lobe (medial frontal gyrus, in the left orbito-frontal cortex and in the left pallidum. The results show that there is an abstractive system in the brain for detecting temporal irregularity, regardless of the source producing it.

  2. Differential maturation of brain signal complexity in the human auditory and visual system

    Directory of Open Access Journals (Sweden)

    Sarah Lippe

    2009-11-01

    Full Text Available Brain development carries with it a large number of structural changes at the local level which impact on the functional interactions of distributed neuronal networks for perceptual processing. Such changes enhance information processing capacity, which can be indexed by estimation of neural signal complexity. Here, we show that during development, EEG signal complexity increases from one month to 5 years of age in response to auditory and visual stimulation. However, the rates of change in complexity were not equivalent for the two responses. Infants’ signal complexity for the visual condition was greater than auditory signal complexity, whereas adults showed the same level of complexity to both types of stimuli. The differential rates of complexity change may reflect a combination of innate and experiential factors on the structure and function of the two sensory systems.

  3. Steady State Visual Evoked Potential Based Brain-Computer Interface for Cognitive Assessment

    DEFF Research Database (Denmark)

    Westergren, Nicolai; Bendtsen, Rasmus L.; Kjær, Troels W.;

    2016-01-01

    decline is important. Cognitive decline may be detected using fullyautomated computerized assessment. Such systems will provide inexpensive and widely available screenings of cognitive ability. The aim of this pilot study is to develop a real time steady state visual evoked potential (SSVEP) based brain-computer...... interface (BCI) for neurological cognitive assessment. It is intended for use by patients who suffer from diseases impairing their motor skills, but are still able to control their gaze. Results are based on 11 healthy test subjects. The system performance have an average accuracy of 100% ± 0%. The test...

  4. Chronic visual dysfunction after blast-induced mild traumatic brain injury.

    Science.gov (United States)

    Magone, M Teresa; Kwon, Ellen; Shin, Soo Y

    2014-01-01

    The purpose of this study was to investigate the long-term visual dysfunction in patients after blast-induced mild traumatic brain injury (mbTBI) using a retrospective case series of 31 patients with mbTBI (>12 mo prior) without eye injuries. Time since mbTBI was 50.5 +/- 19.8 mo. Age at the time of injury was 30.0 +/- 8.3 yr. Mean corrected visual acuity was 20/20. Of the patients, 71% (n = 22) experienced loss of consciousness; 68% (n = 15) of patients in this subgroup were dismounted during the blast injury. Overall, 68% (n = 21) of patients had visual complaints. The most common complaints were photophobia (55%) and difficulty with reading (32%). Of all patients, 25% were diagnosed with convergence insufficiency and 23% had accommodative insufficiency. Patients with more than one mbTBI had a higher rate of visual complaints (87.5%). Asymptomatic patients had a significantly longer time (62.5 +/- 6.2 mo) since the mbTBI than symptomatic patients (42.0 +/- 16.4 mo, p one incidence of mbTBI occurred. We recommend obtaining a careful medical history, evaluation of symptoms, and binocular vision assessment during routine eye examinations in this prepresbyopic patient population.

  5. Anticoagulation for Prosthetic Valves

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Kaneko

    2013-01-01

    Full Text Available Implantation of prosthetic valve requires consideration for anticoagulation. The current guideline recommends warfarin on all mechanical valves. Dabigatran is the new generation anticoagulation medication which is taken orally and does not require frequent monitoring. This drug is approved for treatment for atrial fibrillation and venous thromboembolism, but the latest large trial showed that this drug increases adverse events when used for mechanical valve anticoagulation. On-X valve is the new generation mechanical valve which is considered to require less anticoagulation due to its flow dynamics. The latest study showed that lower anticoagulation level lowers the incidence of bleeding, while the risk of thromboembolism and thrombosis remained the same. Anticoagulation poses dilemma in cases such as pregnancy and major bleeding event. During pregnancy, warfarin can be continued throughout pregnancy and switched to heparin derivative during 6–12 weeks and >36 weeks of gestation. Warfarin can be safely started after 1-2 weeks of discontinuation following major bleeding episode.

  6. Cerebral Visual Impairment: Which Perceptive Visual Dysfunctions Can Be Expected in Children with Brain Damage? A Systematic Review

    Science.gov (United States)

    Boot, F. H.; Pel, J. J. M.; van der Steen, J.; Evenhuis, H. M.

    2010-01-01

    The current definition of Cerebral Visual Impairment (CVI) includes all visual dysfunctions caused by damage to, or malfunctioning of, the retrochiasmatic visual pathways in the absence of damage to the anterior visual pathways or any major ocular disease. CVI is diagnosed by exclusion and the existence of many different causes and symptoms make…

  7. Brain SPECT of chronic fatigue syndrome (CFS): a blinded visual analysis

    International Nuclear Information System (INIS)

    Full text: Chronic fatigue syndrome (CFS) is a debilitating and complex disorder characterised by profound fatigue and neuropsychiatric dysfunction. Previous studies with cerebral perfusion SPECT (rCBF) scans have yielded conflicting results. Most were performed with inhomogeneous patient populations and the findings were not based on a blinded visual analysis. To address this, HMPAO SPECT on a triple head gamma camera was performed on a group of 59 subjects. This group included 32 subjects (16-61 years, 24F and 8M) with moderate CFS based on the Fukuda criteria not on medication and not depressed and 27 normal volunteers (20-56 years, 16F and 11 M). Two blinded reviewers (RC and GC) separately assessed the SPECT studies. 28 brain structures were scored as either definitely abnormal(1), possibly abnormal(2) or normal(3-5). Abnormal results were only found in the temporal lobes and brainstem. The results (Sensitivity/Specificity) based on scores 1 or 2, show that that abnormal score yielded acceptable specificity but low sensitivity. Scores 1 or 2 improved sensitivity but reduced the specificity. This shows that visual analysis of brain SPECT is not a reliable discriminant test for CFS, although quantitative analysis with statistical parametric mapping (SPM) has demonstrated significant abnormalities. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  8. An independent brain-computer interface using covert non-spatial visual selective attention

    Science.gov (United States)

    Zhang, Dan; Maye, Alexander; Gao, Xiaorong; Hong, Bo; Engel, Andreas K.; Gao, Shangkai

    2010-02-01

    In this paper, a novel independent brain-computer interface (BCI) system based on covert non-spatial visual selective attention of two superimposed illusory surfaces is described. Perception of two superimposed surfaces was induced by two sets of dots with different colors rotating in opposite directions. The surfaces flickered at different frequencies and elicited distinguishable steady-state visual evoked potentials (SSVEPs) over parietal and occipital areas of the brain. By selectively attending to one of the two surfaces, the SSVEP amplitude at the corresponding frequency was enhanced. An online BCI system utilizing the attentional modulation of SSVEP was implemented and a 3-day online training program with healthy subjects was carried out. The study was conducted with Chinese subjects at Tsinghua University, and German subjects at University Medical Center Hamburg-Eppendorf (UKE) using identical stimulation software and equivalent technical setup. A general improvement of control accuracy with training was observed in 8 out of 18 subjects. An averaged online classification accuracy of 72.6 ± 16.1% was achieved on the last training day. The system renders SSVEP-based BCI paradigms possible for paralyzed patients with substantial head or ocular motor impairments by employing covert attention shifts instead of changing gaze direction.

  9. A fast way to visualize the brain surface with volume rendering of MRI data.

    Science.gov (United States)

    Matsumoto, S; Asato, R; Konishi, J

    1999-11-01

    The preprocessing of 3-dimensional (3D) MRI data constitutes a bottleneck in the process of visualizing the brain surface with volume rendering. As a fast way to achieve this preprocessing, the authors propose a simple pipeline based on an algorithm of seed-growing type, for approximate segmentation of the intradural space in T1-weighted 3D MRI data. Except for the setting of a seed and four parameters, this pipeline proceeds in an unsupervised manner; no interactive intermediate step is involved. It was tested with 15 datasets from normal adults. The result was reproducible in that as long as the seed was located within the cerebral white matter, identical segmentation was achieved for each dataset. Although the pipeline ran with gross segmentation error along the floor of the cranial cavity, it performed well along the cranial vault so that subsequent volume rendering permitted the observation of the sulco-gyral pattern over cerebral convexities. Use of this pipeline followed by volume rendering is a handy approach to the visualization of the brain surface from 3D MRI data. PMID:10587913

  10. Evaluation of Interactive Visualization on Mobile Computing Platforms for Selection of Deep Brain Stimulation Parameters.

    Science.gov (United States)

    Butson, Christopher R; Tamm, Georg; Jain, Sanket; Fogal, Thomas; Krüger, Jens

    2013-01-01

    In recent years, there has been significant growth in the use of patient-specific models to predict the effects of neuromodulation therapies such as deep brain stimulation (DBS). However, translating these models from a research environment to the everyday clinical workflow has been a challenge, primarily due to the complexity of the models and the expertise required in specialized visualization software. In this paper, we deploy the interactive visualization system ImageVis3D Mobile, which has been designed for mobile computing devices such as the iPhone or iPad, in an evaluation environment to visualize models of Parkinson's disease patients who received DBS therapy. Selection of DBS settings is a significant clinical challenge that requires repeated revisions to achieve optimal therapeutic response, and is often performed without any visual representation of the stimulation system in the patient. We used ImageVis3D Mobile to provide models to movement disorders clinicians and asked them to use the software to determine: 1) which of the four DBS electrode contacts they would select for therapy; and 2) what stimulation settings they would choose. We compared the stimulation protocol chosen from the software versus the stimulation protocol that was chosen via clinical practice (independent of the study). Lastly, we compared the amount of time required to reach these settings using the software versus the time required through standard practice. We found that the stimulation settings chosen using ImageVis3D Mobile were similar to those used in standard of care, but were selected in drastically less time. We show how our visualization system, available directly at the point of care on a device familiar to the clinician, can be used to guide clinical decision making for selection of DBS settings. In our view, the positive impact of the system could also translate to areas other than DBS. PMID:22450824

  11. Steady state visually evoked potentials based Brain computer interface test outside the lab

    Directory of Open Access Journals (Sweden)

    Eduardo Francisco Caicedo Bravo

    2016-06-01

    Full Text Available Context: Steady State Visually Evoked Potentials (SSVEP are brain signals which are one of the most promising signals for Brain Computer Interfaces (BCIs implementation, however, SSVEP based BCI generally are proven in a controlled environment and there are a few tests in demanding conditions.Method: We present a SSVEP based BCI system that was used outside the lab in a noisy environment with distractions, and with the presence of public. For the tests, we showed a maze in a laptop where the user could move an avatar looking for a target that is represented by a house.  In order to move the avatar, the volunteer must stare at one of the four visual stimuli; the four visual stimuli represent the four directions: right, up, left, and down. The system is proven without any calibration procedure.Results: 32 volunteers utilized the system and 20 achieved the target with an accuracy above 60%, including 9 with an accuracy of 100%, 7 achieved the target with an accuracy below 60% and 5 left without achieving the goal. For the volunteers who reached accuracy above 60%, the results of the performance achieved an average of 6,4s for command detections, precision of 79% and information transfer rate (ITR of 8,78 bits/s.Conclusions: We showed a SSVEP based BCI system with low cost, it was proved in a public event, it did not have calibration procedures, it was easy to install, and it was used for people in a wide age range. The results show that it is possible to bring this kind of systems to environments outside the laboratory.

  12. fMRI data visualization with BrainBlend and Blender.

    Science.gov (United States)

    Pyka, Martin; Hertog, Matthias; Fernandez, Raul; Hauke, Sascha; Heider, Dominik; Dannlowski, Udo; Konrad, Carsten

    2010-03-01

    The visualization and exploration of neuroimaging data is important for the analysis of anatomical and functional magnetic resonance (MR) images and thresholded statistical parametric maps. While two-dimensional orthogonal views of neuroimaging data are used to display statistical analyses, real three-dimensional (3d) depictions are helpful for showing the spatial distribution of a functional network, as well as its temporal evolution. However, viewers that are freely available on the internet offer only limited rendering capabilities and depictions of temporal changes of the blood oxygen level-dependent (BOLD) response. In this article, we present BrainBlend, a toolbox for the software package Statistical Parametric Mapping (SPM), that generates voxeldata files to be used with the open-source 3d-software "Blender". Our interface between SPM and Blender permits the use of any Analyze- and Nifti-file for the creation of images and animations of transparent volumetric objects. Different kinds of anatomical, functional and statistical data can be rendered as volumetric objects in order to convey an immediate understanding of the three-dimensional shape. Representations of functional networks can be animated using a time course extracted from the general linear model or the independent component analysis. Relative BOLD activations of functional MR-images can be calculated for a time-resolved depiction of hemodynamic changes. The resulting animation can be displayed along with its corresponding paradigm matrix and the presented stimuli. BrainBlend is particularly suitable for the visual exploration of interactions between functional networks, for time-resolved animations of BOLD changes and meets high demands on visual quality in images and animations. PMID:20033355

  13. Reactivity of dogs' brain oscillations to visual stimuli measured with non-invasive electroencephalography.

    Directory of Open Access Journals (Sweden)

    Miiamaaria V Kujala

    Full Text Available Studying cognition of domestic dogs has gone through a renaissance within the last decades. However, although the behavioral studies of dogs are beginning to be common in the field of animal cognition, the neural events underlying cognition remain unknown. Here, we employed a non-invasive electroencephalography, with adhesive electrodes attached to the top of the skin, to measure brain activity of from 8 domestic dogs (Canis familiaris while they stayed still to observe photos of dog and human faces. Spontaneous oscillatory activity of the dogs, peaking in the sensors over the parieto-occipital cortex, was suppressed statistically significantly during visual task compared with resting activity at the frequency of 15-30 Hz. Moreover, a stimulus-induced low-frequency (~2-6 Hz suppression locked to the stimulus onset was evident at the frontal sensors, possibly reflecting a motor rhythm guiding the exploratory eye movements. The results suggest task-related reactivity of the macroscopic oscillatory activity in the dog brain. To our knowledge, the study is the first to reveal non-invasively measured reactivity of brain electrophysiological oscillations in healthy dogs, and it has been based purely on positive operant conditional training, without the need for movement restriction or medication.

  14. Stimulus Specificity of Brain-Computer Interfaces Based on Code Modulation Visual Evoked Potentials.

    Directory of Open Access Journals (Sweden)

    Qingguo Wei

    Full Text Available A brain-computer interface (BCI based on code modulated visual evoked potentials (c-VEP is among the fastest BCIs that have ever been reported, but it has not yet been given a thorough study. In this study, a pseudorandom binary M sequence and its time lag sequences are utilized for modulation of different stimuli and template matching is adopted as the method for target recognition. Five experiments were devised to investigate the effect of stimulus specificity on target recognition and we made an effort to find the optimal stimulus parameters for size, color and proximity of the stimuli, length of modulation sequence and its lag between two adjacent stimuli. By changing the values of these parameters and measuring classification accuracy of the c-VEP BCI, an optimal value of each parameter can be attained. Experimental results of ten subjects showed that stimulus size of visual angle 3.8°, white, spatial proximity of visual angle 4.8° center to center apart, modulation sequence of length 63 bits and the lag of 4 bits between adjacent stimuli yield individually superior performance. These findings provide a basis for determining stimulus presentation of a high-performance c-VEP based BCI system.

  15. An Auditory-Tactile Visual Saccade-Independent P300 Brain-Computer Interface.

    Science.gov (United States)

    Yin, Erwei; Zeyl, Timothy; Saab, Rami; Hu, Dewen; Zhou, Zongtan; Chau, Tom

    2016-02-01

    Most P300 event-related potential (ERP)-based brain-computer interface (BCI) studies focus on gaze shift-dependent BCIs, which cannot be used by people who have lost voluntary eye movement. However, the performance of visual saccade-independent P300 BCIs is generally poor. To improve saccade-independent BCI performance, we propose a bimodal P300 BCI approach that simultaneously employs auditory and tactile stimuli. The proposed P300 BCI is a vision-independent system because no visual interaction is required of the user. Specifically, we designed a direction-congruent bimodal paradigm by randomly and simultaneously presenting auditory and tactile stimuli from the same direction. Furthermore, the channels and number of trials were tailored to each user to improve online performance. With 12 participants, the average online information transfer rate (ITR) of the bimodal approach improved by 45.43% and 51.05% over that attained, respectively, with the auditory and tactile approaches individually. Importantly, the average online ITR of the bimodal approach, including the break time between selections, reached 10.77 bits/min. These findings suggest that the proposed bimodal system holds promise as a practical visual saccade-independent P300 BCI. PMID:26678249

  16. Prosthetic stomatitis with removable dentures

    Directory of Open Access Journals (Sweden)

    Rozalieva Yu.Yu.

    2012-06-01

    Full Text Available The Research Objective: To study patients with prosthetic stomatitis, who use the removable laminar dentures. Materials: The consultations and treatment of 79 patients aged 47-65 years have been conducted. The patients have been divided into two clinical groups. The first clinical group (39 persons with the performance of immediate prosthet-ics; the second control clinical group (40 persons — the permanent dentures were produced without the preliminary instruction. Results: All the patients, having the laminar dentures without the preliminary use of immediate constructions of dentures, in spite of repeated correction of them, have had changes of dentures and transitory fold. Patients have been exposed to prosthetic stomatitis of different etiology (without trauma; the single-shot or multiple correction of dentures by the method of rebasing with using of cold cure plastics has been made. Conclusion: Structural and functional changes of dentition during the prosthetic stomatitis lead to disorders, associated by the mucositis. Use of the term of «prosthetic stomatitis» reflects etiological and pathogenetic component of changes in the denture-supporting tissues

  17. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

    Directory of Open Access Journals (Sweden)

    Carolyn D Langen

    Full Text Available Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1 middle-aged versus elderly subjects; and (2 patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only

  18. [Prosthetic dental alloys. 1].

    Science.gov (United States)

    Quintero Engelmbright, M A

    1990-11-01

    A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements. PMID:2132464

  19. [Prosthetic dental alloys (2)].

    Science.gov (United States)

    Quintero Englembright, M A

    1990-12-01

    A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements. PMID:2132470

  20. Brain activation in response to randomized visual stimulation as obtained from conjunction and differential analysis: an fMRI study

    International Nuclear Information System (INIS)

    The objective of this multiple-subjects functional magnetic resonance imaging (fMRI) study was to identify the common brain areas that are activated when viewing black-and-white checkerboard pattern stimuli of various shapes, pattern and size and to investigate specific brain areas that are involved in processing static and moving visual stimuli. Sixteen participants viewed the moving (expanding ring, rotating wedge, flipping hour glass and bowtie and arc quadrant) and static (full checkerboard) stimuli during an fMRI scan. All stimuli have black-and-white checkerboard pattern. Statistical parametric mapping (SPM) was used in generating brain activation. Differential analyses were implemented to separately search for areas involved in processing static and moving stimuli. In general, the stimuli of various shapes, pattern and size activated multiple brain areas mostly in the left hemisphere. The activation in the right middle temporal gyrus (MTG) was found to be significantly higher in processing moving visual stimuli as compared to static stimulus. In contrast, the activation in the left calcarine sulcus and left lingual gyrus were significantly higher for static stimulus as compared to moving stimuli. Visual stimulation of various shapes, pattern and size used in this study indicated left lateralization of activation. The involvement of the right MTG in processing moving visual information was evident from differential analysis, while the left calcarine sulcus and left lingual gyrus are the areas that are involved in the processing of static visual stimulus

  1. Activation in brain energy regulation and reward centers by food cues varies with choice of visual stimulus

    OpenAIRE

    Schur, Ellen; Kleinhans, Natalia; Goldberg, Jack; Buchwald, Dedra; Schwartz, Michael; Maravilla, Ken

    2009-01-01

    Objective To develop a noninvasive method of studying brain mechanisms involved in energy homeostasis and appetite regulation in humans by using visual food cues that are relevant to individuals attempting weight loss. Design Functional magnetic resonance imaging (fMRI) was used to compare brain activation in regions of interest between groups of food photographs. Participants 10 healthy, nonobese women who were not dieting for weight loss. Measurements Independent raters viewed food photogra...

  2. The effect of visual training for patients with visual field defects due to brain damage : a systematic review

    NARCIS (Netherlands)

    Bouwmeester, Lies; Heutink, Joost; Lucas, Cees

    2007-01-01

    The objective of this review was to evaluate whether systematic visual training leads to ( 1) a restitution of the visual field ( restoration), ( 2) an increase in the visual search field size or an improvement in scanning strategies (compensation) and ( 3) a transfer of training-related improvement

  3. Steady State Visual Evoked Potential Based Brain-Computer Interface for Cognitive Assessment

    DEFF Research Database (Denmark)

    Westergren, Nicolai; Bendtsen, Rasmus L.; Kjær, Troels W.;

    2016-01-01

    decline is important. Cognitive decline may be detected using fullyautomated computerized assessment. Such systems will provide inexpensive and widely available screenings of cognitive ability. The aim of this pilot study is to develop a real time steady state visual evoked potential (SSVEP) based brain-computer...... subjects achieved an information transfer rate (ITR) of 14:64 bits/min ± 7:63 bits=min and a subject test performance of 47:22% ± 34:10%. This study suggests that BCI may be applicable in practice as a computerized cognitive assessment tool. However, many improvements are required for the system...... interface (BCI) for neurological cognitive assessment. It is intended for use by patients who suffer from diseases impairing their motor skills, but are still able to control their gaze. Results are based on 11 healthy test subjects. The system performance have an average accuracy of 100% ± 0%. The test...

  4. Individual visual working memory capacities and related brain oscillatory activities are modulated by color preferences

    Directory of Open Access Journals (Sweden)

    Masahiro eKawasaki

    2012-11-01

    Full Text Available Subjective preferences affect many processes, including motivation, along with individual differences. Although incentive motivations are proposed to increase our limited visual working memory (VWM capacity, much less is known about the effects of subjective preferences on VWM-related brain systems, such as the prefrontal and parietal cortices. Here, we investigate the differences in VWM capacities and brain activities during presentation of preferred and non-preferred colors. To this end, we used time-frequency analyses of electroencephalograph (EEG data recorded during a delayed-response task. Behavioral results showed that the individual VWM capacities of preferred colors were significantly higher than those of non-preferred colors. The EEG results showed that the frontal theta and beta amplitudes for maintenance of preferred colors were higher than those of non-preferred colors. Interestingly, the frontal beta amplitudes were consistent with recent EEG recordings of the effects of reward on VWM systems, in that they were strongly and individually correlated with increasing VWM capacities from non-preferred to preferred colors. These results suggest that subjective preferences affect VWM systems in a similar manner to reward-incentive motivations.

  5. Effects of visual working memory on brain information processing of irrelevant auditory stimuli.

    Directory of Open Access Journals (Sweden)

    Jiagui Qu

    Full Text Available Selective attention has traditionally been viewed as a sensory processing modulator that promotes cognitive processing efficiency by favoring relevant stimuli while inhibiting irrelevant stimuli. However, the cross-modal processing of irrelevant information during working memory (WM has been rarely investigated. In this study, the modulation of irrelevant auditory information by the brain during a visual WM task was investigated. The N100 auditory evoked potential (N100-AEP following an auditory click was used to evaluate the selective attention to auditory stimulus during WM processing and at rest. N100-AEP amplitudes were found to be significantly affected in the left-prefrontal, mid-prefrontal, right-prefrontal, left-frontal, and mid-frontal regions while performing a high WM load task. In contrast, no significant differences were found between N100-AEP amplitudes in WM states and rest states under a low WM load task in all recorded brain regions. Furthermore, no differences were found between the time latencies of N100-AEP troughs in WM states and rest states while performing either the high or low WM load task. These findings suggested that the prefrontal cortex (PFC may integrate information from different sensory channels to protect perceptual integrity during cognitive processing.

  6. Perceptual moments of conscious visual experience inferred from oscillatory brain activity.

    Science.gov (United States)

    Smith, Marie L; Gosselin, Frédéric; Schyns, Philippe G

    2006-04-01

    Transient periods of synchronized oscillating neuronal discharges in the brain have been proposed to support the discrete perceptual moments underlying conscious visual experience. However, the information content of these perceptual moments remains a critical challenge to the understanding of consciousness. We uncovered this information content in four observers who consciously perceived each interpretation of the ambiguous Dali painting Slave Market with the Disappearing Bust of Voltaire. For each individual observer, we isolated the stimulus spatial frequency (SF) features underlying their overt judgments of the input as "the nuns" and "Voltaire". Every 2 ms between stimulus onset and overt response, we derived the sensitivity of the observer's oscillatory brain activity (in the theta, alpha, and beta bandwidths) to these SF features. Then, in each bandwidth, we estimated the moments (between stimulus onset and perceptual judgment) when perception-specific SF features were maximally integrated, corresponding to perceptual moments. We show that the centroparietal beta oscillations support perceptual moments underlying the conscious perception of the nuns, whereas theta oscillations support the perception of Voltaire. For both perceptions, we reveal the specific information content of these perceptual moments. PMID:16567643

  7. Genetic effects on source level evoked and induced oscillatory brain responses in a visual oddball task.

    Science.gov (United States)

    Antonakakis, Marios; Zervakis, Michalis; van Beijsterveldt, Catharina E M; Boomsma, Dorret I; De Geus, Eco J C; Micheloyannis, Sifis; Smit, Dirk J A

    2016-02-01

    Stimuli in simple oddball target detection paradigms cause evoked responses in brain potential. These responses are heritable traits, and potential endophenotypes for clinical phenotypes. These stimuli also cause responses in oscillatory activity, both evoked responses phase-locked to stimulus presentation and phase-independent induced responses. Here, we investigate whether phase-locked and phase-independent oscillatory responses are heritable traits. Oscillatory responses were examined in EEG recordings from 213 twin pairs (91 monozygotic and 122 dizygotic twins) performing a visual oddball task. After group Independent Component Analysis (group-ICA) and time-frequency decomposition, individual differences in evoked and induced oscillatory responses were compared between MZ and DZ twin pairs. Induced (phase-independent) oscillatory responses consistently showed the highest heritability (24-55%) compared to evoked (phase-locked) oscillatory responses and spectral energy, which revealed lower heritability at 1-35.6% and 4.5-32.3%, respectively. Since the phase-independent induced response encodes functional aspects of the brain response to target stimuli different from evoked responses, we conclude that the modulation of ongoing oscillatory activity may serve as an additional endophenotype for behavioral phenotypes and psychiatric genetics.

  8. Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks

    Directory of Open Access Journals (Sweden)

    Mona eMoisala

    2015-02-01

    Full Text Available Using functional magnetic resonance imaging, we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking, divided attention (i.e., dual-tasking did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention.

  9. Brains of verbal memory specialists show anatomical differences in language, memory and visual systems.

    Science.gov (United States)

    Hartzell, James F; Davis, Ben; Melcher, David; Miceli, Gabriele; Jovicich, Jorge; Nath, Tanmay; Singh, Nandini Chatterjee; Hasson, Uri

    2016-05-01

    We studied a group of verbal memory specialists to determine whether intensive oral text memory is associated with structural features of hippocampal and lateral-temporal regions implicated in language processing. Professional Vedic Sanskrit Pandits in India train from childhood for around 10years in an ancient, formalized tradition of oral Sanskrit text memorization and recitation, mastering the exact pronunciation and invariant content of multiple 40,000-100,000 word oral texts. We conducted structural analysis of gray matter density, cortical thickness, local gyrification, and white matter structure, relative to matched controls. We found massive gray matter density and cortical thickness increases in Pandit brains in language, memory and visual systems, including i) bilateral lateral temporal cortices and ii) the anterior cingulate cortex and the hippocampus, regions associated with long and short-term memory. Differences in hippocampal morphometry matched those previously documented for expert spatial navigators and individuals with good verbal working memory. The findings provide unique insight into the brain organization implementing formalized oral knowledge systems. PMID:26188261

  10. Prediction of auditory and visual p300 brain-computer interface aptitude.

    Directory of Open Access Journals (Sweden)

    Sebastian Halder

    Full Text Available OBJECTIVE: Brain-computer interfaces (BCIs provide a non-muscular communication channel for patients with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS or otherwise motor impaired people and are also used for motor rehabilitation in chronic stroke. Differences in the ability to use a BCI vary from person to person and from session to session. A reliable predictor of aptitude would allow for the selection of suitable BCI paradigms. For this reason, we investigated whether P300 BCI aptitude could be predicted from a short experiment with a standard auditory oddball. METHODS: Forty healthy participants performed an electroencephalography (EEG based visual and auditory P300-BCI spelling task in a single session. In addition, prior to each session an auditory oddball was presented. Features extracted from the auditory oddball were analyzed with respect to predictive power for BCI aptitude. RESULTS: Correlation between auditory oddball response and P300 BCI accuracy revealed a strong relationship between accuracy and N2 amplitude and the amplitude of a late ERP component between 400 and 600 ms. Interestingly, the P3 amplitude of the auditory oddball response was not correlated with accuracy. CONCLUSIONS: Event-related potentials recorded during a standard auditory oddball session moderately predict aptitude in an audiory and highly in a visual P300 BCI. The predictor will allow for faster paradigm selection. SIGNIFICANCE: Our method will reduce strain on patients because unsuccessful training may be avoided, provided the results can be generalized to the patient population.

  11. GPU-accelerated brain connectivity reconstruction and visualization in large-scale electron micrographs

    KAUST Repository

    Jeong, Wonki

    2011-01-01

    This chapter introduces a GPU-accelerated interactive, semiautomatic axon segmentation and visualization system. Two challenging problems have been addressed: the interactive 3D axon segmentation and the interactive 3D image filtering and rendering of implicit surfaces. The reconstruction of neural connections to understand the function of the brain is an emerging and active research area in neuroscience. With the advent of high-resolution scanning technologies, such as 3D light microscopy and electron microscopy (EM), reconstruction of complex 3D neural circuits from large volumes of neural tissues has become feasible. Among them, only EM data can provide sufficient resolution to identify synapses and to resolve extremely narrow neural processes. These high-resolution, large-scale datasets pose challenging problems, for example, how to process and manipulate large datasets to extract scientifically meaningful information using a compact representation in a reasonable processing time. The running time of the multiphase level set segmentation method has been measured on the CPU and GPU. The CPU version is implemented using the ITK image class and the ITK distance transform filter. The numerical part of the CPU implementation is similar to the GPU implementation for fair comparison. The main focus of this chapter is introducing the GPU algorithms and their implementation details, which are the core components of the interactive segmentation and visualization system. © 2011 Copyright © 2011 NVIDIA Corporation and Wen-mei W. Hwu Published by Elsevier Inc. All rights reserved..

  12. The role of different cues in the brain mechanism on visual spatial attention

    Institute of Scientific and Technical Information of China (English)

    SONG Weiqun; LUO Yuejia; CHI Song; JI Xunming; LING Feng; ZHAO Lun; WANG Maobin; SHI Jiannong

    2006-01-01

    The visual spatial attention mechanism in the brain was studied in 16 young subjects through the visual search paradigm of precue-target by the event-related potential (ERP) technique, with the attentive ranges cued by different scales of Chinese character and region cues. The results showed that the response time for Chinese character cues was much longer than that for region cues especially for small region cues. With the exterior interferences, the target stimuli recognition under region cues was much quicker than that under Chinese character cues. Compared with that under region cues, targets under Chinese character cues could lead to increase of the posterior P1,decrease of the N1 and increase of the P2. It should also be noted that the differences between region cues and Chinese character cues were affected by the interference types. Under exterior interferences, no significant difference was found between region cues and Chinese character cues; however, it was not the case under the interior interferences. Considering the difference between the exterior interferences and the interior interferences, we could conclude that with the increase of difficulty in target recognition there was obvious difference in the consumption of anterior frontal resources by target stimuli under the two kinds of cues.

  13. Visual Scanning in the Recognition of Facial Affect in Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Suzane Vassallo

    2011-05-01

    Full Text Available We investigated the visual scanning strategy employed by a group of individuals with a severe traumatic brain injury (TBI during a facial affect recognition task. Four males with a severe TBI were matched for age and gender with 4 healthy controls. Eye movements were recorded while pictures of static emotional faces were viewed (i.e., sad, happy, angry, disgusted, anxious, surprised. Groups were compared with respect to accuracy in labelling the emotional facial expression, reaction time, number and duration of fixations to internal (i.e., eyes + nose + mouth, and external (i.e., all remaining regions of the stimulus. TBI participants demonstrated significantly reduced accuracy and increased latency in facial affect recognition. Further, they demonstrated no significant difference in the number or duration of fixations to internal versus external facial regions. Control participants, however, fixated more frequently and for longer periods of time upon internal facial features. Impaired visual scanning can contribute to inaccurate interpretation of facial expression and this can disrupt interpersonal communication. The scanning strategy demonstrated by our TBI group appears more ‘widespread’ than that employed by their normal counterparts. Further work is required to elucidate the nature of the scanning strategy used and its potential variance in TBI.

  14. Exploring combinations of auditory and visual stimuli for gaze-independent brain-computer interfaces.

    Directory of Open Access Journals (Sweden)

    Xingwei An

    Full Text Available For Brain-Computer Interface (BCI systems that are designed for users with severe impairments of the oculomotor system, an appropriate mode of presenting stimuli to the user is crucial. To investigate whether multi-sensory integration can be exploited in the gaze-independent event-related potentials (ERP speller and to enhance BCI performance, we designed a visual-auditory speller. We investigate the possibility to enhance stimulus presentation by combining visual and auditory stimuli within gaze-independent spellers. In this study with N = 15 healthy users, two different ways of combining the two sensory modalities are proposed: simultaneous redundant streams (Combined-Speller and interleaved independent streams (Parallel-Speller. Unimodal stimuli were applied as control conditions. The workload, ERP components, classification accuracy and resulting spelling speed were analyzed for each condition. The Combined-speller showed a lower workload than uni-modal paradigms, without the sacrifice of spelling performance. Besides, shorter latencies, lower amplitudes, as well as a shift of the temporal and spatial distribution of discriminative information were observed for Combined-speller. These results are important and are inspirations for future studies to search the reason for these differences. For the more innovative and demanding Parallel-Speller, where the auditory and visual domains are independent from each other, a proof of concept was obtained: fifteen users could spell online with a mean accuracy of 87.7% (chance level <3% showing a competitive average speed of 1.65 symbols per minute. The fact that it requires only one selection period per symbol makes it a good candidate for a fast communication channel. It brings a new insight into the true multisensory stimuli paradigms. Novel approaches for combining two sensory modalities were designed here, which are valuable for the development of ERP-based BCI paradigms.

  15. Detection and identification of microbes in prosthetic joint infections by culture and molecular methods

    DEFF Research Database (Denmark)

    Xu, Yijuan; Schønheyder, Henrik Carl; Ehrlich, Garth;

    used for analysis, particularly prosthetic implants yielded more positive results. Furthermore, the presence of bacteria as both single cells and microcolonies were visualized by fluorescence in situ hybridization using peptide nucleic acid and DNA probes and confocal scanning laser microscopy......, indicating biofilm formation. In conclusion, this study indicated that to improve the microbiological diagnosis of prosthetic joint infections molecular methods may be useful supplements to routine cultures, and the current intraoperative sampling strategy needs to be optimized....

  16. Contralateral Cortical Organisation of Information in Visual Short-Term Memory: Evidence from Lateralized Brain Activity during Retrieval

    Science.gov (United States)

    Fortier-Gauthier, Ulysse; Moffat, Nicolas; Dell'Acqua, Robert; McDonald, John J.; Jolicoeur, Pierre

    2012-01-01

    We studied brain activity during retention and retrieval phases of two visual short-term memory (VSTM) experiments. Experiment 1 used a balanced memory array, with one color stimulus in each hemifield, followed by a retention interval and a central probe, at the fixation point that designated the target stimulus in memory about which to make a…

  17. A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem.

    Science.gov (United States)

    McClay, Wilbert A; Yadav, Nancy; Ozbek, Yusuf; Haas, Andy; Attias, Hagaii T; Nagarajan, Srikantan S

    2015-01-01

    Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI) for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG) brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user's intent for specific keyboard strikes or mouse button presses. The BCI's data analytics OPEN ACCESS Brain. Sci. 2015, 5 420 of a subject's MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse. PMID:26437432

  18. A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem

    Directory of Open Access Journals (Sweden)

    Wilbert A. McClay

    2015-09-01

    Full Text Available Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user’s intent for specific keyboard strikes or mouse button presses. The BCI’s data analytics OPEN ACCESS Brain. Sci. 2015, 5 420 of a subject’s MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse.

  19. A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem.

    Science.gov (United States)

    McClay, Wilbert A; Yadav, Nancy; Ozbek, Yusuf; Haas, Andy; Attias, Hagaii T; Nagarajan, Srikantan S

    2015-09-30

    Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI) for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG) brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user's intent for specific keyboard strikes or mouse button presses. The BCI's data analytics OPEN ACCESS Brain. Sci. 2015, 5 420 of a subject's MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse.

  20. The effect of repetition of infrequent familiar and unfamiliar visual patterns on components of the event-related brain potential.

    NARCIS (Netherlands)

    A. Kok; H. de Looren de Jong

    1980-01-01

    Examined changes in the waveforms of the event-related brain potential (ERP) during repeated presentations of infrequent-familiar and infrequent-unfamiliar visual patterns; Ss were 12 male university students. The EEG waveforms were averaged separately for each presentation of the 2 types of stimuli

  1. Candida infection of a prosthetic shoulder joint

    International Nuclear Information System (INIS)

    A heroin addict developed a Candida parapsilosis infection in a prosthetic shoulder joint. Radiographs showed loose fragments of cement with prosthetic loosening. The patient was treated with removal of the prosthesis and intravenous amphotericin B followed by oral ketoconazole. (orig.)

  2. Windows into the Visual Brain: New Discoveries about the Visual System, Its Functions, and Implications for Practitioners

    Science.gov (United States)

    Jan, James E.; Heaven, Roberta K. B.; Matsuba, Carey; Langley, M. Beth; Roman-Lantzy, Christine; Anthony, Tanni L

    2013-01-01

    Introduction: In recent years, major progress has been made in understanding the human visual system because of new investigative techniques. These developments often contradict older concepts about visual function. Methods: A detailed literature search and interprofessional discussions. Results: Recent innovative neurological tests are described…

  3. Successful thrombolysis for prosthetic pulmonary valve obstruction.

    OpenAIRE

    Lopez, J. A.; Strickman, N E; Jin, B S; X. G. Li; Phan, B; Zeluff, B J; Wilansky, S

    1995-01-01

    Thrombosis is a serious complication of prosthetic heart valve operations. In recent years, systemic thrombolysis has emerged as a suitable alternative to surgery. Experience with thrombosis of pulmonary prosthetic valves is very limited. We report a case of successful administration of intravenous streptokinase for thrombosis of a St. Jude Medical prosthetic valve 3 weeks after pulmonary valve replacement.

  4. Complex network inference from P300 signals: Decoding brain state under visual stimulus for able-bodied and disabled subjects

    Science.gov (United States)

    Gao, Zhong-Ke; Cai, Qing; Dong, Na; Zhang, Shan-Shan; Bo, Yun; Zhang, Jie

    2016-10-01

    Distinguishing brain cognitive behavior underlying disabled and able-bodied subjects constitutes a challenging problem of significant importance. Complex network has established itself as a powerful tool for exploring functional brain networks, which sheds light on the inner workings of the human brain. Most existing works in constructing brain network focus on phase-synchronization measures between regional neural activities. In contrast, we propose a novel approach for inferring functional networks from P300 event-related potentials by integrating time and frequency domain information extracted from each channel signal, which we show to be efficient in subsequent pattern recognition. In particular, we construct brain network by regarding each channel signal as a node and determining the edges in terms of correlation of the extracted feature vectors. A six-choice P300 paradigm with six different images is used in testing our new approach, involving one able-bodied subject and three disabled subjects suffering from multiple sclerosis, cerebral palsy, traumatic brain and spinal-cord injury, respectively. We then exploit global efficiency, local efficiency and small-world indices from the derived brain networks to assess the network topological structure associated with different target images. The findings suggest that our method allows identifying brain cognitive behaviors related to visual stimulus between able-bodied and disabled subjects.

  5. From head to toe: Evidence for selective brain activation reflecting visual perception of whole individuals

    Directory of Open Access Journals (Sweden)

    Laura eSchmalzl

    2012-05-01

    Full Text Available Our ability to recognize other people’s faces and bodies is crucial for our social interactions. Previous neuroimaging studies have repeatedly demonstrated the existence of brain areas that selectively respond to visually presented faces and bodies. In daily life, however, we see "whole" people and not just isolated faces and bodies, and the question remains of how information from these two categories of stimuli is integrated at a neural level. Are faces and bodies merely processed independently, or are there neural populations that actually code for whole individuals? In the current study we addressed this question using a functional magnetic resonance imaging adaptation (fMRI-A paradigm involving the sequential presentation of visual stimuli depicting whole individuals. It is known that adaptation effects for a component of a stimulus only occur in neural populations that are sensitive to that particular component. The design of our experiment allowed us to measure adaptation effects occurring when either just the face, just the body, or both the face and the body of an individual were repeated. Crucially, we found novel evidence for the existence of neural populations in fusiform as well as extrastriate regions that showed selective adaptation for whole individuals, which could not be merely explained by the sum of adaptation for face and body respectively. The functional specificity of these neural populations is likely to support fast and accurate recognition and integration of information conveyed by both faces and bodies. Hence, they can be assumed to play an important role for identity as well as emotion recognition in everyday life.

  6. A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem

    Science.gov (United States)

    McClay, Wilbert A.; Yadav, Nancy; Ozbek, Yusuf; Haas, Andy; Attias, Hagaii T.; Nagarajan, Srikantan S.

    2015-01-01

    Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI) for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG) brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user’s intent for specific keyboard strikes or mouse button presses. The BCI’s data analytics of a subject’s MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse. PMID:26437432

  7. Visualization of Time-Dependent Distribution of Rifampicin in Rat Brain Using MALDI MSI and Quantitative LCMS/MS.

    Science.gov (United States)

    Shobo, Adeola; Bratkowska, Dominika; Baijnath, Sooraj; Naiker, Suhashni; Bester, Linda A; Singh, Sanil D; Maguire, Glenn Eamond Mitchell; Kruger, Hendrik Gert; Govender, Thavendran

    2015-06-01

    Rifampicin (RIF) is a major component for short-course chemotherapy against tuberculosis, since it is active against rapidly metabolizing as well as dormant bacteria. According to the Lipinski rules, RIF should not enter the blood-brain barrier. Visualization of tissue drug distribution is of major importance in pharmacological studies; thus, far imaging of RIF in the brain has been limited to positron emission tomography. We propose using matrix-assisted laser desorption/ionization mass spectrometry imaging techniques as a suitable alternative for the visualization and localization of drug tissue distribution. Using the liquid chromatography mass spectrometric (LCMS) technique, we were able to quantify the concentrations of RIF in the uninfected rat brain; we paired this with matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) to show the time-dependent manner in which RIF is able to enter the brain. Our results show that even at the minute concentrations measured with LCMS/MS we were able visualize the drug and show its exact distribution in the rat brain. Other available methods require nuclear labeling and the detection of gamma rays produced by labeled compounds to visualize the compound and its localization; MALDI MSI is a more recently developed technique, which can provide detailed information on drug distribution in tissues when compared to other imaging techniques. This study shows that without any requirement for complex preprocessing we are able to produce images with a relatively improved resolution and localization than those acquired using more complex imaging methods, showing MALDI MSI to be an invaluable tool in drug distribution studies.

  8. A new high-speed visual stimulation method for gaze-contingent eye movement and brain activity studies

    Directory of Open Access Journals (Sweden)

    Fabio eRichlan

    2013-07-01

    Full Text Available Approaches using eye movements as markers of ongoing brain activity to investigate perceptual and cognitive processes were able to implement highly sophisticated paradigms driven by eye movement recordings. Crucially, these paradigms involve display changes that have to occur during the time of saccadic blindness, when the subject is unaware of the change. Therefore, a combination of high-speed eye tracking and high-speed visual stimulation is required in these paradigms. For combined eye movement and brain activity studies (e.g., fMRI, EEG, MEG, fast and exact timing of display changes is especially important, because of the high susceptibility of these methods to visual stimulation. Eye tracking systems already achieve sampling rates up to 2000 Hz, but recent LCD technologies for computer screens reduced the temporal resolution to mostly 60 Hz, which is too slow for gaze-contingent display changes. We developed a high-speed video projection system, which is capable of reliably delivering display changes within the time frame of < 5 ms. This could not be achieved even with the fastest CRT monitors available (< 16 ms. The present video projection system facilitates the realization of cutting-edge eye movement research requiring reliable high-speed visual stimulation (e.g., gaze-contingent display changes, short-time presentation, masked priming. Moreover, this system can be used for fast visual presentation in order to assess brain activity using various methods, such as electroencephalography (EEG and functional magnetic resonance imaging (fMRI. The latter technique was previously excluded from high-speed visual stimulation, because it is not possible to operate conventional CRT monitors in the strong magnetic field of an MRI scanner. Therefore, the present video projection system offers new possibilities for studying eye movement-related brain activity using a combination of eye tracking and fMRI.

  9. Brain networks involved in haptic and visual identification of facial expressions of emotion: an fMRI study.

    Science.gov (United States)

    Kitada, Ryo; Johnsrude, Ingrid S; Kochiyama, Takanori; Lederman, Susan J

    2010-01-15

    Previous neurophysiological and neuroimaging studies have shown that a cortical network involving the inferior frontal gyrus (IFG), inferior parietal lobe (IPL) and cortical areas in and around the posterior superior temporal sulcus (pSTS) region is employed in action understanding by vision and audition. However, the brain regions that are involved in action understanding by touch are unknown. Lederman et al. (2007) recently demonstrated that humans can haptically recognize facial expressions of emotion (FEE) surprisingly well. Here, we report a functional magnetic resonance imaging (fMRI) study in which we test the hypothesis that the IFG, IPL and pSTS regions are involved in haptic, as well as visual, FEE identification. Twenty subjects haptically or visually identified facemasks with three different FEEs (disgust, neutral and happiness) and casts of shoes (shoes) of three different types. The left posterior middle temporal gyrus, IPL, IFG and bilateral precentral gyrus were activated by FEE identification relative to that of shoes, regardless of sensory modality. By contrast, an inferomedial part of the left superior parietal lobule was activated by haptic, but not visual, FEE identification. Other brain regions, including the lingual gyrus and superior frontal gyrus, were activated by visual identification of FEEs, relative to haptic identification of FEEs. These results suggest that haptic and visual FEE identification rely on distinct but overlapping neural substrates including the IFG, IPL and pSTS region. PMID:19770059

  10. Visual and Haptic Shape Processing in the Human Brain: Unisensory Processing, Multisensory Convergence, and Top-Down Influences.

    Science.gov (United States)

    Lee Masson, Haemy; Bulthé, Jessica; Op de Beeck, Hans P; Wallraven, Christian

    2016-08-01

    Humans are highly adept at multisensory processing of object shape in both vision and touch. Previous studies have mostly focused on where visually perceived object-shape information can be decoded, with haptic shape processing receiving less attention. Here, we investigate visuo-haptic shape processing in the human brain using multivoxel correlation analyses. Importantly, we use tangible, parametrically defined novel objects as stimuli. Two groups of participants first performed either a visual or haptic similarity-judgment task. The resulting perceptual object-shape spaces were highly similar and matched the physical parameter space. In a subsequent fMRI experiment, objects were first compared within the learned modality and then in the other modality in a one-back task. When correlating neural similarity spaces with perceptual spaces, visually perceived shape was decoded well in the occipital lobe along with the ventral pathway, whereas haptically perceived shape information was mainly found in the parietal lobe, including frontal cortex. Interestingly, ventrolateral occipito-temporal cortex decoded shape in both modalities, highlighting this as an area capable of detailed visuo-haptic shape processing. Finally, we found haptic shape representations in early visual cortex (in the absence of visual input), when participants switched from visual to haptic exploration, suggesting top-down involvement of visual imagery on haptic shape processing. PMID:26223258

  11. A Fuzzy Integral Ensemble Method in Visual P300 Brain-Computer Interface

    Directory of Open Access Journals (Sweden)

    Francesco Cavrini

    2016-01-01

    Full Text Available We evaluate the possibility of application of combination of classifiers using fuzzy measures and integrals to Brain-Computer Interface (BCI based on electroencephalography. In particular, we present an ensemble method that can be applied to a variety of systems and evaluate it in the context of a visual P300-based BCI. Offline analysis of data relative to 5 subjects lets us argue that the proposed classification strategy is suitable for BCI. Indeed, the achieved performance is significantly greater than the average of the base classifiers and, broadly speaking, similar to that of the best one. Thus the proposed methodology allows realizing systems that can be used by different subjects without the need for a preliminary configuration phase in which the best classifier for each user has to be identified. Moreover, the ensemble is often capable of detecting uncertain situations and turning them from misclassifications into abstentions, thereby improving the level of safety in BCI for environmental or device control.

  12. Coding of visual object features and feature conjunctions in the human brain.

    Directory of Open Access Journals (Sweden)

    Jasna Martinovic

    Full Text Available Object recognition is achieved through neural mechanisms reliant on the activity of distributed coordinated neural assemblies. In the initial steps of this process, an object's features are thought to be coded very rapidly in distinct neural assemblies. These features play different functional roles in the recognition process--while colour facilitates recognition, additional contours and edges delay it. Here, we selectively varied the amount and role of object features in an entry-level categorization paradigm and related them to the electrical activity of the human brain. We found that early synchronizations (approx. 100 ms increased quantitatively when more image features had to be coded, without reflecting their qualitative contribution to the recognition process. Later activity (approx. 200-400 ms was modulated by the representational role of object features. These findings demonstrate that although early synchronizations may be sufficient for relatively crude discrimination of objects in visual scenes, they cannot support entry-level categorization. This was subserved by later processes of object model selection, which utilized the representational value of object features such as colour or edges to select the appropriate model and achieve identification.

  13. Event-related power modulations of brain activity preceding visually guided saccades.

    Science.gov (United States)

    Brignani, Debora; Maioli, Claudio; Maria Rossini, Paolo; Miniussi, Carlo

    2007-03-01

    To analyze the characteristics of the event-related desynchronization (ERD) and synchronization (ERS) of cortical rhythms during the preparation and execution of a lateralized eye movement, EEG was recorded in normal subjects during a visually guided task. Alpha and beta bands were investigated in three temporal intervals: a sensory period, a delay period and a saccade preparation period time locked with saccade onset. Modulations of ERD/ERS power, coupled with the task, reached the largest amplitudes over the frontal and parieto-occipital regions. Differences of oscillatory activity in the alpha bands revealed an intriguing pattern of asymmetry in parieto-occipital areas. Rightward saccades induced a larger desynchronization with respect to the leftward saccades in the left hemisphere, but not in the right. If representative, these findings are congruent to the established right-hemisphere dominance of the brain areas that direct attention. Moreover differences between the two alpha types emerged in the frontal areas before and during the saccade preparation periods, indicative of differential engagement of these areas depending on the task demands. In conclusion, the present approach shows that planning eye movements is linked with covert orienting of spatial attention and may supply a useful method for studying eye movements and selective attention-related processes. PMID:17196943

  14. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation

    Directory of Open Access Journals (Sweden)

    Mikkel Wallentin

    2016-01-01

    Full Text Available Klinefelter syndrome (47, XXY (KS is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49 responded to whether the words “GREEN” or “RED” were displayed in green or red (incongruent versus congruent colors. One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying “GREEN” or “RED” had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system.

  15. Optimal level activity of matrix metalloproteinases is critical for adult visual plasticity in the healthy and stroke-affected brain.

    Science.gov (United States)

    Pielecka-Fortuna, Justyna; Kalogeraki, Evgenia; Fortuna, Michal G; Löwel, Siegrid

    2016-01-01

    The ability of the adult brain to undergo plastic changes is of particular interest in medicine, especially regarding recovery from injuries or improving learning and cognition. Matrix metalloproteinases (MMPs) have been associated with juvenile experience-dependent primary visual cortex (V1) plasticity, yet little is known about their role in this process in the adult V1. Activation of MMPs is a crucial step facilitating structural changes in a healthy brain; however, upon brain injury, upregulated MMPs promote the spread of a lesion and impair recovery. To clarify these seemingly opposing outcomes of MMP-activation, we examined the effects of MMP-inhibition on experience-induced plasticity in healthy and stoke-affected adult mice. In healthy animals, 7-day application of MMP-inhibitor prevented visual plasticity. Additionally, treatment with MMP-inhibitor once but not twice following stroke rescued plasticity, normally lost under these conditions. Our data imply that an optimal level of MMP-activity is crucial for adult visual plasticity to occur. PMID:26609811

  16. Brain

    Science.gov (United States)

    ... will return after updating. Resources Archived Modules Updates Brain Cerebrum The cerebrum is the part of the ... the outside of the brain and spinal cord. Brain Stem The brain stem is the part of ...

  17. Three-dimensional visualization of functional brain tissue and functional magnetic resonance imaging-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex

    International Nuclear Information System (INIS)

    Objective: To assess the value of three -dimensional visualization of functional brain tissue and the functional magnetic resonance imaging (fMRI)-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex. Method: Sixty patients with tumor located in the central sulcus were enrolled. Thirty patients were randomly assigned to function group and 30 to control group. Patients in function group underwent fMRI to localize the functional brain tissues. Then the function information was transferred to the neurosurgical navigator. The patients in control group underwent surgery with navigation without function information. The therapeutic effect, excision rate. improvement of motor function, and survival quality during follow-up were analyzed. Result: All patients in function group were accomplished visualization of functional brain tissues and fMRI-integrated neuronavigation. The locations of tumors, central sulcus and motor cortex were marked during the operation. The fMRI -integrated information played a great role in both pre- and post-operation. Pre-operation: designing the location of the skin flap and window bone, determining the relationship between the tumor and motor cortex, and designing the pathway for the resection. Post- operation: real-time navigation of relationship between the tumor and motor cortex, assisting to localize the motor cortex using interoperation ultra-sound for correcting the displacement by the CSF outflow and collapsing tumor. The patients in the function group had better results than the patients in the control group in therapeutic effect (u=2.646, P=0.008), excision rate (χ=7.200, P<0.01), improvement of motor function (u=2.231, P=0.026), and survival quality (KPS uc= 2.664, P=0.008; Zubrod -ECOG -WHO uc=2.135, P=0.033). Conclusions: Using preoperative three -dimensional visualization of cerebral function tissue and the fMRI-integrated neuronavigation technology, combining intraoperative accurate positioning

  18. Selective visual attention to drive cognitive brain machine interfaces: from concepts to neurofeedback and rehabilitation applications

    Directory of Open Access Journals (Sweden)

    Elaine eAstrand

    2014-08-01

    Full Text Available Brain Machine Interfaces (BMI using motor cortical activity to drive an external effector like a screen cursor or a robotic arm have seen enormous success and proven their great rehabilitation potential. An emerging parallel effort is now directed to BMIs controlled by endogenous cognitive activity, also called cognitive BMIs. While more challenging, this approach opens new dimensions to the rehabilitation of cognitive disorders. In the present work, we focus on BMIs driven by visuospatial attention signals and we provide a critical review of these studies in the light of the accumulated knowledge about the psychophysics, anatomy and neurophysiology of visual spatial attention. Importantly, we provide a unique comparative overview of the several studies, ranging from noninvasive to invasive human and non-human primates studies, that decode attention-related information from ongoing neuronal activity. We discuss these studies in the light of the challenges attention-driven cognitive BMIs have to face. In a second part of the review, we discuss past and current attention-based neurofeedback studies, describing both the covert effects of neurofeedback onto neuronal activity and its overt behavioral effects. Importantly, we compare neurofeedback studies based on the amplitude of cortical activity to studies based on the enhancement of cortical information content. Last, we discuss several lines of future research and applications for attention-driven cognitive BCIs, including the rehabilitation of cognitive deficits, restored communication in locked-in patients, and open-field applications for enhanced cognition in normal subjects. The core motivation of this work is the key idea that the improvement of current cognitive BMIs for therapeutic and open field applications needs to be grounded in a proper interdisciplinary understanding of the physiology of the cognitive function of interest, be it spatial attention, working memory or any other

  19. Advancing the detection of steady-state visual evoked potentials in brain-computer interfaces

    Science.gov (United States)

    Abu-Alqumsan, Mohammad; Peer, Angelika

    2016-06-01

    Objective. Spatial filtering has proved to be a powerful pre-processing step in detection of steady-state visual evoked potentials and boosted typical detection rates both in offline analysis and online SSVEP-based brain-computer interface applications. State-of-the-art detection methods and the spatial filters used thereby share many common foundations as they all build upon the second order statistics of the acquired Electroencephalographic (EEG) data, that is, its spatial autocovariance and cross-covariance with what is assumed to be a pure SSVEP response. The present study aims at highlighting the similarities and differences between these methods. Approach. We consider the canonical correlation analysis (CCA) method as a basis for the theoretical and empirical (with real EEG data) analysis of the state-of-the-art detection methods and the spatial filters used thereby. We build upon the findings of this analysis and prior research and propose a new detection method (CVARS) that combines the power of the canonical variates and that of the autoregressive spectral analysis in estimating the signal and noise power levels. Main results. We found that the multivariate synchronization index method and the maximum contrast combination method are variations of the CCA method. All three methods were found to provide relatively unreliable detections in low signal-to-noise ratio (SNR) regimes. CVARS and the minimum energy combination methods were found to provide better estimates for different SNR levels. Significance. Our theoretical and empirical results demonstrate that the proposed CVARS method outperforms other state-of-the-art detection methods when used in an unsupervised fashion. Furthermore, when used in a supervised fashion, a linear classifier learned from a short training session is able to estimate the hidden user intention, including the idle state (when the user is not attending to any stimulus), rapidly, accurately and reliably.

  20. Visualizing the distribution of synapses from individual neurons in the mouse brain.

    Directory of Open Access Journals (Sweden)

    Ling Li

    Full Text Available BACKGROUND: Proper function of the mammalian brain relies on the establishment of highly specific synaptic connections among billions of neurons. To understand how complex neural circuits function, it is crucial to precisely describe neuronal connectivity and the distributions of synapses to and from individual neurons. METHODS AND FINDINGS: In this study, we present a new genetic synaptic labeling method that relies on expression of a presynaptic marker, synaptophysin-GFP (Syp-GFP in individual neurons in vivo. We assess the reliability of this method and use it to analyze the spatial patterning of synapses in developing and mature cerebellar granule cells (GCs. In immature GCs, Syp-GFP is distributed in both axonal and dendritic regions. Upon maturation, it becomes strongly enriched in axons. In mature GCs, we analyzed synapses along their ascending segments and parallel fibers. We observe no differences in presynaptic distribution between GCs born at different developmental time points and thus having varied depths of projections in the molecular layer. We found that the mean densities of synapses along the parallel fiber and the ascending segment above the Purkinje cell (PC layer are statistically indistinguishable, and higher than previous estimates. Interestingly, presynaptic terminals were also found in the ascending segments of GCs below and within the PC layer, with the mean densities two-fold lower than that above the PC layer. The difference in the density of synapses in these parts of the ascending segment likely reflects the regional differences in postsynaptic target cells of GCs. CONCLUSIONS: The ability to visualize synapses of single neurons in vivo is valuable for studying synaptogenesis and synaptic plasticity within individual neurons as well as information flow in neural circuits.

  1. Validation of the prosthetic esthetic index

    DEFF Research Database (Denmark)

    Özhayat, Esben B; Dannemand, Katrine

    2014-01-01

    OBJECTIVES: In order to diagnose impaired esthetics and evaluate treatments for these, it is crucial to evaluate all aspects of oral and prosthetic esthetics. No professionally administered index currently exists that sufficiently encompasses comprehensive prosthetic esthetics. This study aimed...... to validate a new comprehensive index, the Prosthetic Esthetic Index (PEI), for professional evaluation of esthetics in prosthodontic patients. MATERIAL AND METHODS: The content, criterion, and construct validity; the test-retest, inter-rater, and internal consistency reliability; and the sensitivity...

  2. Changes in ganglion cell physiology during retinal degeneration influence excitability by prosthetic electrodes

    Science.gov (United States)

    Cho, Alice; Ratliff, Charles; Sampath, Alapakkam; Weiland, James

    2016-04-01

    Objective. Here we investigate ganglion cell physiology in healthy and degenerating retina to test its influence on threshold to electrical stimulation. Approach. Age-related Macular Degeneration and Retinitis Pigmentosa cause blindness via outer retinal degeneration. Inner retinal pathways that transmit visual information to the central brain remain intact, so direct electrical stimulation from prosthetic devices offers the possibility for visual restoration. Since inner retinal physiology changes during degeneration, we characterize physiological properties and responses to electrical stimulation in retinal ganglion cells (RGCs) of both wild type mice and the rd10 mouse model of retinal degeneration. Main results. Our aggregate results support previous observations that elevated thresholds characterize diseased retinas. However, a physiology-driven classification scheme reveals distinct sub-populations of ganglion cells with thresholds either normal or strongly elevated compared to wild-type. When these populations are combined, only a weakly elevated threshold with large variance is observed. The cells with normal threshold are more depolarized at rest and exhibit periodic oscillations. Significance. During degeneration, physiological changes in RGCs affect the threshold stimulation currents required to evoke action potentials.

  3. Validation of the Vertical Heterophoria Symptom Questionnaire (VHS-Q) In Patients with Balance Problems and Binocular Visual Dysfunction after Acquired Brain Injury

    DEFF Research Database (Denmark)

    Schow, Trine; Teasdale, Thomas William; Arendt Rasmussen, Morten

    2016-01-01

    Trine Schow, Thomas William Teasdale and Morten Arendt Rasmussen Validation of the Vertical Heterophoria Symptom Questionnaire (VHS-Q) In Patients with Balance Problems and Binocular Visual Dysfunction after Acquired Brain Injury. SOJ Psychology (in Press)......Trine Schow, Thomas William Teasdale and Morten Arendt Rasmussen Validation of the Vertical Heterophoria Symptom Questionnaire (VHS-Q) In Patients with Balance Problems and Binocular Visual Dysfunction after Acquired Brain Injury. SOJ Psychology (in Press)...

  4. Brain network involved in visual processing of movement stimuli used in upper limb robotic training: an fMRI study

    Directory of Open Access Journals (Sweden)

    Nocchi Federico

    2012-07-01

    Full Text Available Abstract Background The potential of robot-mediated therapy and virtual reality in neurorehabilitation is becoming of increasing importance. However, there is limited information, using neuroimaging, on the neural networks involved in training with these technologies. This study was intended to detect the brain network involved in the visual processing of movement during robotic training. The main aim was to investigate the existence of a common cerebral network able to assimilate biological (human upper limb and non-biological (abstract object movements, hence testing the suitability of the visual non-biological feedback provided by the InMotion2 Robot. Methods A visual functional Magnetic Resonance Imaging (fMRI task was administered to 22 healthy subjects. The task required observation and retrieval of motor gestures and of the visual feedback used in robotic training. Functional activations of both biological and non-biological movements were examined to identify areas activated in both conditions, along with differential activity in upper limb vs. abstract object trials. Control of response was also tested by administering trials with congruent and incongruent reaching movements. Results The observation of upper limb and abstract object movements elicited similar patterns of activations according to a caudo-rostral pathway for the visual processing of movements (including specific areas of the occipital, temporal, parietal, and frontal lobes. Similarly, overlapping activations were found for the subsequent retrieval of the observed movement. Furthermore, activations of frontal cortical areas were associated with congruent trials more than with the incongruent ones. Conclusions This study identified the neural pathway associated with visual processing of movement stimuli used in upper limb robot-mediated training and investigated the brain’s ability to assimilate abstract object movements with human motor gestures. In both conditions

  5. Fiber-array based optogenetic prosthetic system for stimulation therapy

    Science.gov (United States)

    Gu, Ling; Cote, Chris; Tejeda, Hector; Mohanty, Samarendra

    2012-02-01

    Recent advent of optogenetics has enabled activation of genetically-targeted neuronal cells using low intensity blue light with high temporal precision. Since blue light is attenuated rapidly due to scattering and absorption in neural tissue, optogenetic treatment of neurological disorders may require stimulation of specific cell types in multiple regions of the brain. Further, restoration of certain neural functions (vision, and auditory etc) requires accurate spatio-temporal stimulation patterns rather than just precise temporal stimulation. In order to activate multiple regions of the central nervous system in 3D, here, we report development of an optogenetic prosthetic comprising of array of fibers coupled to independently-controllable LEDs. This design avoids direct contact of LEDs with the brain tissue and thus does not require electrical and heat isolation, which can non-specifically stimulate and damage the local brain regions. The intensity, frequency, and duty cycle of light pulses from each fiber in the array was controlled independently using an inhouse developed LabView based program interfaced with a microcontroller driving the individual LEDs. While the temporal profile of the light pulses was controlled by varying the current driving the LED, the beam profile emanating from each fiber tip could be sculpted by microfabrication of the fiber tip. The fiber array was used to stimulate neurons, expressing channelrhodopsin-2, in different locations within the brain or retina. Control of neural activity in the mice cortex, using the fiber-array based prosthetic, is evaluated from recordings made with multi-electrode array (MEA). We also report construction of a μLED array based prosthetic for spatio-temporal stimulation of cortex.

  6. Parallel neural pathways in higher visual centers of the Drosophila brain that mediate wavelength-specific behavior

    Directory of Open Access Journals (Sweden)

    Hideo eOtsuna

    2014-02-01

    Full Text Available Compared with connections between the retinae and primary visual centers, relatively less is known in both mammals and insects about the functional segregation of neural pathways connecting primary and higher centers of the visual processing cascade. Here, using the Drosophila visual system as a model, we demonstrate two levels of parallel computation in the pathways that connect primary visual centers of the optic lobe to computational circuits embedded within deeper centers in the central brain. We show that a seemingly simple achromatic behavior, namely phototaxis, is under the control of several independent pathways, each of which is responsible for navigation towards unique wavelengths. Silencing just one pathway is enough to disturb phototaxis towards one characteristic monochromatic source, whereas phototactic behavior towards white light is not affected. The response spectrum of each demonstrable pathway is different from that of individual photoreceptors, suggesting subtractive computations. A choice assay between two colors showed that these pathways are responsible for navigation towards, but not for the detection itself of, the monochromatic light. The present study provides novel insights about how visual information is separated and processed in parallel to achieve robust control of an innate behavior.

  7. Effects of environmental contaminant exposure on visual brain development: a prospective electrophysiological study in school-aged children.

    Science.gov (United States)

    Ethier, Audrey-Anne; Muckle, Gina; Bastien, Célyne; Dewailly, Éric; Ayotte, Pierre; Arfken, Cynthia; Jacobson, Sandra W; Jacobson, Joseph L; Saint-Amour, Dave

    2012-10-01

    The Inuit from Nunavik (Northern Québec) are one of the most highly exposed populations to environmental contaminants in North America mainly due to the bioaccumulation of contaminants in fish and marine mammals that constitute an important part of their diet. This follow-up study aimed to assess the impact of exposure to contaminants on visual brain development in school-age Inuit children (mean age=10.9 years). Concentrations of polychlorinated biphenyls (PCBs), mercury (Hg), and lead (Pb) were measured in umbilical cord blood and again in blood samples at the time of testing, reflecting pre- and current exposure, respectively. Pattern-reversal visual evoked potentials (VEPs) were scalp-recorded at the occipital cortex. Visual stimulation consisted of achromatic gratings presented at four visual contrast levels: 95%, 30%, 12% and 4%. The relation between environmental contaminant body burdens and VEPs was examined by regression analysis controlling for confounding variables, including fish nutrients and other toxicants. No significant association was found for PCB exposure after statistical adjustments. Cord blood mercury level was associated with a reduction of the N75 amplitude at the highest contrast level and with a delay of the N75 latency at the 12% contrast level. Prenatal exposure to lead was associated with a delay of the N150 latency at most contrast levels. This study suggests that heavy metal exposure, in particular during the gestational period, can impair the development of visual processing.

  8. Optical microangiography enabling visualization of change in meninges after traumatic brain injury in mice in vivo

    Science.gov (United States)

    Choi, Woo June; Qin, Wan; Qi, Xiaoli; Wang, Ruikang K.

    2016-03-01

    Traumatic brain injury (TBI) is a form of brain injury caused by sudden impact on brain by an external mechanical force. Following the damage caused at the moment of injury, TBI influences pathophysiology in the brain that takes place within the minutes or hours involving alterations in the brain tissue morphology, cerebral blood flow (CBF), and pressure within skull, which become important contributors to morbidity after TBI. While many studies for the TBI pathophysiology have been investigated with brain cortex, the effect of trauma on intracranial tissues has been poorly studied. Here, we report use of high-resolution optical microangiography (OMAG) to monitor the changes in cranial meninges beneath the skull of mouse after TBI. TBI is induced on a brain of anesthetized mouse by thinning the skull using a soft drill where a series of drilling exert mechanical stress on the brain through the skull, resulting in mild brain injury. Intracranial OMAG imaging of the injured mouse brain during post-TBI phase shows interesting pathophysiological findings in the meningeal layers such as widening of subdural space as well as vasodilation of subarachnoid vessels. These processes are acute and reversible within hours. The results indicate potential of OMAG to explore mechanism involved following TBI on small animals in vivo.

  9. Processing of visual gravitational motion in the peri-sylvian cortex: Evidence from brain-damaged patients.

    Science.gov (United States)

    Maffei, Vincenzo; Mazzarella, Elisabetta; Piras, Fabrizio; Spalletta, Gianfranco; Caltagirone, Carlo; Lacquaniti, Francesco; Daprati, Elena

    2016-05-01

    Rich behavioral evidence indicates that the brain estimates the visual direction and acceleration of gravity quite accurately, and the underlying mechanisms have begun to be unraveled. While the neuroanatomical substrates of gravity direction processing have been studied extensively in brain-damaged patients, to our knowledge no such study exists for the processing of visual gravitational motion. Here we asked 31 stroke patients to intercept a virtual ball moving along the vertical under either natural gravity or artificial reversed gravity. Twenty-seven of them also aligned a luminous bar to the vertical direction (subjective visual vertical, SVV). Using voxel-based lesion-symptom mapping as well as lesion subtraction analysis, we found that lesions mainly centered on the posterior insula are associated with greater deviations of SVV, consistent with several previous studies. Instead, lesions mainly centered on the parietal operculum decrease the ability to discriminate natural from unnatural gravitational acceleration with a timed motor response in the interception task. Both the posterior insula and the parietal operculum belong to the vestibular cortex, and presumably receive multisensory information about the gravity vector. We speculate that an internal model estimating the effects of gravity on visual objects is constructed by transforming the vestibular estimates of mechanical gravity, which are computed in the brainstem and cerebellum, into internalized estimates of virtual gravity, which are stored in the cortical vestibular network. The present lesion data suggest a specific role for the parietal operculum in detecting the mismatch between predictive signals from the internal model and the online visual signals. PMID:27007069

  10. Contralateral cortical organisation of information in visual short-term memory: evidence from lateralized brain activity during retrieval.

    Science.gov (United States)

    Fortier-Gauthier, Ulysse; Moffat, Nicolas; Dell'Acqua, Roberto; McDonald, John J; Jolicœur, Pierre

    2012-07-01

    We studied brain activity during retention and retrieval phases of two visual short-term memory (VSTM) experiments. Experiment 1 used a balanced memory array, with one color stimulus in each hemifield, followed by a retention interval and a central probe, at the fixation point that designated the target stimulus in memory about which to make a determination of orientation. Retrieval of information from VSTM was associated with an event-related lateralization (ERL) with a contralateral negativity relative to the visual field from which the probed stimulus was originally encoded, suggesting a lateralized organization of VSTM. The scalp distribution of the retrieval ERL was more anterior than what is usually associated with simple maintenance activity, which is consistent with the involvement of different brain structures for these distinct visual memory mechanisms. Experiment 2 was like Experiment 1, but used an unbalanced memory array consisting of one lateral color stimulus in a hemifield and one color stimulus on the vertical mid-line. This design enabled us to separate lateralized activity related to target retrieval from distractor processing. Target retrieval was found to generate a negative-going ERL at electrode sites found in Experiment 1, and suggested representations were retrieved from anterior cortical structures. Distractor processing elicited a positive-going ERL at posterior electrodes sites, which could be indicative of a return to baseline of retention activity for the discarded memory of the now-irrelevant stimulus, or an active inhibition mechanism mediating distractor suppression.

  11. Real-time fMRI brain-computer interface : development of a "motivational feedback" subsystem for the regulation of visual cue reactivity.

    OpenAIRE

    Sokunbi, Moses O.; Linden, David E. J.; Habes, Isabelle; Johnston, Stephen; Ihssen, Niklas

    2014-01-01

    Here we present a novel neurofeedback subsystem for the presentation of motivationally relevant visual feedback during the self-regulation of functional brain activation. Our “motivational neurofeedback” approach uses functional magnetic resonance imaging (fMRI) signals elicited by visual cues (pictures) and related to motivational processes such as craving or hunger. The visual feedback subsystem provides simultaneous feedback through these images as their size corresponds to the magnitude o...

  12. Real-time fMRI brain-computer interface: Development of a "motivational feedback" subsystem for the regulation of visual cue reactivity

    OpenAIRE

    Sokunbi, Moses O.; Stephen Johnston

    2014-01-01

    Here we present a novel neurofeedback subsystem for the presentation of motivationally relevant visual feedback during the self-regulation of functional brain activation. Our “motivational neurofeedback” approach uses functional magnetic resonance imaging (fMRI) signals elicited by visual cues (pictures) and related to motivational processes such as craving or hunger. The visual feedback subsystem provides simultaneous feedback through these images as their size corresponds to the magnitude o...

  13. The role of experience and sleep in visual learning : behavioral and brain imaging investigation

    OpenAIRE

    Duhoux Mathieu, Stéphanie

    2009-01-01

    Identifying and recognizing visual objects are crucial skills that enable to interact with the environment adequately. Most of the time, these processes are rapid and effortless. However, recognition is the final outcome of complex processes, including the creation of representations of visual objects and their consolidation into memory, which mechanisms and neural correlates remain largely unknown. The present work reports four studies, aiming at better understanding visual learning, and tes...

  14. Brain polarization of parietal cortex augments training-induced improvement of visual exploratory and attentional skills.

    Science.gov (United States)

    Bolognini, Nadia; Fregni, Felipe; Casati, Carlotta; Olgiati, Elena; Vallar, Giuseppe

    2010-08-19

    Recent evidence suggests that behavioural gains induced by behavioural training are maximized when combined with techniques of cortical neuromodulation, such as transcranial Direct Current Stimulation (tDCS). Here we address the validity of this appealing approach by investigating the effect of coupling a multisensory visual field exploration training with tDCS of the posterior parietal cortex (PPC). The multisensory visual field exploration training consisted in the practice of visual search through the systematic audio-visual stimulation of the visual field. Neurologically unimpaired participants performed a bimodal exploration training for 30 min, while simultaneously receiving anodal-excitatory PPC tDCS or sham tDCS. In two different experiments, the left and the right hemisphere were stimulated. Outcome measures included visual exploration speed at different time intervals during the training, and the post-training effects on tests assessing visual scanning and visuo-spatial orienting. Results show that PPC tDCS applied to the right, but not to the left, hemisphere increases the training-induced behavioural improvement of visual exploration, as compared to sham tDCS. In addition, right PPC tDCS brings about an improvement of covert visual orienting, in a task different from the visual search practice. In an additional experiment, we confirm that right parietal tDCS by itself, even without the associated training, can lead to enhancement of visual search. Overall, anodal PPC tDCS is a promising technique to enhance visuo-spatial abilities, when combined to a visual field exploration training task. PMID:20599813

  15. Novel Materials for Prosthetic Liners

    Science.gov (United States)

    Ragolta, Carolina I.; Morford, Megan

    2011-01-01

    Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury that reduce quality of life. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications. Three tests were performed on several types of aerogel to assess the properties of each material. Moisture vapor permeability was tested by incubating four aerogel varieties with an artificial sweat solution at 37.0 C and less than 20% relative humidity for 24 hours. Two aerogel varieties were eliminated from the study due to difficulties in handling the material, and further testing proceeded with Pyrogel in 2.0 and 6.0 mm thicknesses. Force distribution was tested by compressing samples under a load of 4448 N at a rate of 2.5 mm/min. Biofilm formation was tested in a high-shear CDC Biofilm Reactor. Results showed that 2.0 mm Pyrogel blanket allowed 55.7 plus or minus 28.7% of an artificial sweat solution to transpire, and 35.5 plus or minus 27.8% transpired through 6.0 mm Pyrogel blanket. Samples also outperformed the load-bearing capabilities of existing liner materials. No statistically significant difference was found between the two Pyrogel thicknesses for either moisture vapor permeability or force distribution. In addition, biofilm formation results showed no change between the two Pyrogel thicknesses. The breathability and load bearing properties of aerogel make it a suitable material for application to prosthetic liners.

  16. Visual awareness suppression by pre-stimulus brain stimulation; a neural effect.

    Science.gov (United States)

    Jacobs, Christianne; Goebel, Rainer; Sack, Alexander T

    2012-01-01

    Transcranial magnetic stimulation (TMS) has established the functional relevance of early visual cortex (EVC) for visual awareness with great temporal specificity non-invasively in conscious human volunteers. Many studies have found a suppressive effect when TMS was applied over EVC 80-100 ms after the onset of the visual stimulus (post-stimulus TMS time window). Yet, few studies found task performance to also suffer when TMS was applied even before visual stimulus presentation (pre-stimulus TMS time window). This pre-stimulus TMS effect, however, remains controversially debated and its origin had mainly been ascribed to TMS-induced eye-blinking artifacts. Here, we applied chronometric TMS over EVC during the execution of a visual discrimination task, covering an exhaustive range of visual stimulus-locked TMS time windows ranging from -80 pre-stimulus to 300 ms post-stimulus onset. Electrooculographical (EoG) recordings, sham TMS stimulation, and vertex TMS stimulation controlled for different types of non-neural TMS effects. Our findings clearly reveal TMS-induced masking effects for both pre- and post-stimulus time windows, and for both objective visual discrimination performance and subjective visibility. Importantly, all effects proved to be still present after post hoc removal of eye blink trials, suggesting a neural origin for the pre-stimulus TMS suppression effect on visual awareness. We speculate based on our data that TMS exerts its pre-stimulus effect via generation of a neural state which interacts with subsequent visual input.

  17. Brucella Endocarditis in Prosthetic Valves

    Science.gov (United States)

    Mehanic, Snjezana; Mulabdic, Velida; Baljic, Rusmir; Hadzovic-Cengic, Meliha; Pinjo, Fikret; Hadziosmanovic, Vesna; Topalovic, Jasna

    2012-01-01

    SUMMARY CONFLICT OF INTEREST: none declared. Introduction Brucella endocarditis (BE) is a rare but severe and potentially lethal manifestation of brucellosis. Pre-existing valves lesions and prosthetic valves (PV) are favorable for BE. Case report We represent the case of a 46-year-old man who was treated at the Clinic for Infectious Diseases, Clinical Center of Sarajevo University, as blood culture positive (Brucella melitensis) mitral and aortic PV endocarditis. He was treated with combined anti-brucella and cardiac therapy. Surgical intervention was postponed due to cardiac instability. Four months later he passed away. Surgery was not performed. PMID:24493988

  18. NIRS monitoring of muscle contraction to control a prosthetic device

    Science.gov (United States)

    Bianchi, Thomas; Zambarbieri, Daniela; Beltrami, Giorgio; Verni, Gennaro

    1999-01-01

    The fitting of upper-extremity amputees requires special efforts, and its significance has been increased by the development of the myoelectrically controlled prosthetic arm. This solution is not free of problems due to the nature of the amputation, to the electromagnetic noise affecting the myelectrical signal and to the perspiration due to the contact between socket and the residual limb. Starting from the fact that NIRS and electromyographic signals are similar during a muscle contraction, we have first studied the NIRS signal during forearm muscle contractions in normal and amputee subjects. Then a new system to interface the NIRS unit and the myoelectrical prosthetic hand has been developed. The NIRS unit has been used as optical sensor and all the operations (I/O and signal processing) are performed via software. This system has been tested on normal and amputee subjects performing hand grasping using a visual biofeedback control scheme. All the subjects have been able to perform these operations demonstrating the NIRS technique. This could represent an alternative solution for controlling a prosthetic device.

  19. Evaluation of the limits of visual detection of image misregistration in a brain fluorine-18 fluorodeoxyglucose PET-MRI study

    International Nuclear Information System (INIS)

    In routine clinical work, registration accuracy is assessed by visual inspection. However, the accuracy of visual assessment of registration has not been evaluated. This study establishes the limits of visual detection of misregistration in a registered brain fluorine-18 fluorodeoxyglucose positron emission tomography to magnetic resonance image volume. The ''best'' registered image volume was obtained by automatic registration using mutual information optimization. Translational movements by 1 mm, 2 mm, 3 mm and 4 mm, and rotational movements by 1 , 2 , 3 and 4 in the positive and negative directions in the x- (lateral), y- (anterior-posterior) and z- (axial) axes were introduced to this standard. These 48 images plus six ''best'' registered images were presented in random sequence to five observers for visual categorization of registration accuracy. No observer detected a definite misregistration in the ''best'' registered image. Evaluation for inter-observer variation using observer pairings showed a high percentage of agreement in assigned categories for both translational and rotational misregistrations. Assessment of the limits of detection of misregistration showed that a 2-mm translational misregistration was detectable by all observers in the x- and y-axes and 3-mm translational misregistration in the z-axis. With rotational misregistrations, rotation around the z-axis was detectable by all at 2 rotation whereas rotation around the y-axis was detected at 3-4 . Rotation around the x-axis was not symmetric with a positive rotation being identified at 2 whereas negative rotation was detected by all only at 4 . Therefore, visual analysis appears to be a sensitive and practical means to assess image misregistration accuracy. The awareness of the limits of visual detection of misregistration will lead to increase care when evaluating registration quality in both research and clinical settings. (orig.). With 6 figs., 3 tabs

  20. Face recognition in simulated prosthetic vision: face detection-based image processing strategies

    Science.gov (United States)

    Wang, Jing; Wu, Xiaobei; Lu, Yanyu; Wu, Hao; Kan, Han; Chai, Xinyu

    2014-08-01

    Objective. Given the limited visual percepts elicited by current prosthetic devices, it is essential to optimize image content in order to assist implant wearers to achieve better performance of visual tasks. This study focuses on recognition of familiar faces using simulated prosthetic vision. Approach. Combined with region-of-interest (ROI) magnification, three face extraction strategies based on a face detection technique were used: the Viola-Jones face region, the statistical face region (SFR) and the matting face region. Main results. These strategies significantly enhanced recognition performance compared to directly lowering resolution (DLR) with Gaussian dots. The inclusion of certain external features, such as hairstyle, was beneficial for face recognition. Given the high recognition accuracy achieved and applicable processing speed, SFR-ROI was the preferred strategy. DLR processing resulted in significant face gender recognition differences (i.e. females were more easily recognized than males), but these differences were not apparent with other strategies. Significance. Face detection-based image processing strategies improved visual perception by highlighting useful information. Their use is advisable for face recognition when using low-resolution prosthetic vision. These results provide information for the continued design of image processing modules for use in visual prosthetics, thus maximizing the benefits for future prosthesis wearers.

  1. Tolerability and Effectiveness of Contact Lenses in Mild Traumatic Brain Injury with Visual Discomfort: A Case Series

    Directory of Open Access Journals (Sweden)

    Len V. Hua, PhD

    2014-01-01

    Full Text Available Background: Over one million people in the United States annually have traumatic incidents that lead to traumatic brain injury (TBI. Asthenopia or eyestrain is frequently a clinical complaint with TBI patients. However, little is studied or known in the literature about the potential of contact lens correction in the management of mild TBI (mTBI with accommodative dysfunction. This pilot study examines the tolerability, effectiveness, and clinical utility of multifocal contact lenses in a subset of mTBI patients with visual discomfort. Methods: This was a controlled, crossover study using Proclear EP Multifocal contact lenses, compared to Proclear Single Vision contact lenses, for five subjects between the ages of 24 and 31 years of age with history of mTBI. Visual symptoms were evaluated using the Convergence Insufficiency Symptom Survey. Visual function was examined by standard visual tests, including visual acuity, extraocular motility (EOM, pupil size, near point of convergence (NPC, vergence, phoria, NRA/PRA, accommodative and vergence facility, and stereoacuity. Subjects were randomized to wear either Proclear Sphere (single vision or Proclear EP Multifocal contact lenses, each for a duration of two weeks. Results: Five mTBI subjects were enrolled in the study. Comprehensive vision examinations of all subjects prior to the study revealed normal ocular health with the exception of visual symptoms such as eyestrain and headache. Two subjects appreciated the beneficial effects of multifocal contact lenses. The other three subjects did not experience substantial benefits of multifocal contact lenses. Nevertheless, all subjects successfully tolerated daylong contact lens wear. Conclusions: Most eye care professionals face the daunting task of how best to manage complex mTBI cases. One of the lingering effects of TBI is often visual symptoms due to oculomotor dysfunction. Multiple treatment modalities may be necessary to alleviate chronic visual

  2. Single trial predictors for gating motor-imagery brain-computer interfaces based on sensorimotor rhythm and visual evoked potentials

    Directory of Open Access Journals (Sweden)

    Andrew eGeronimo

    2016-04-01

    Full Text Available For brain-computer interfaces (BCIs that utilize visual cues to direct the user, the neural signals extracted by the computer are representative of ongoing processes, visual evoked responses, and voluntary modulation. We proposed to use three brain signatures for predicting success on a single trial of a BCI task. The first two features, the amplitude and phase of the pre-trial mu amplitude, were chosen as a correlate for cortical excitability. The remaining feature, related to the visually evoked response to the cue, served as a possible measure of fixation and attention to the task. Of these three features, mu rhythm amplitude over the central electrodes at the time of cue presentation and to a lesser extent the single trial visual evoked response were correlated with the success on the subsequent imagery task. Despite the potential for gating trials using these features, an offline gating simulation was limited in its ability to produce an increase in device throughput. This discrepancy highlights a distinction between the identification of predictive features, and the use of this knowledge in an online BCI. Using such a system, we cannot assume that the user will respond similarly when faced with a scenario where feedback is altered by trials that are gated on a regular basis. The results of this study suggest the possibility of using individualized, pre-task neural signatures for personalized and asynchronous (self-paced BCI applications, although these effects need to be quantified in a real-time adaptive scenario in a future study.

  3. Visual hallucinations of autobiographic memory and asomatognosia: a case of epilepsy due to brain cysticercosis.

    Science.gov (United States)

    Orjuela-Rojas, Juan Manuel; Ramírez-Bermúdez, Jesús; Martínez-Juárez, Iris E; Kerik, Nora Estela; Diaz Meneses, Iván; Pérez-Gay, Fernanda Juárez

    2015-01-01

    The current study describes the case of a woman with symptomatic epilepsy due to brain cysticercosis acquired during childhood. During her adolescence, she developed seizures characterized by metamorphopsia, hallucinations of autobiographic memory and, finally, asomatognosia. Magnetic brain imaging showed a calcified lesion in the right occipitotemporal cortex, and positron emission tomography imaging confirmed the presence of interictal hypometabolism in two regions: the right parietal cortex and the right lateral and posterior temporal cortex. We discuss the link between these brain areas and the symptoms described under the concepts of epileptogenic lesion, epileptogenic zone, functional deficit zone, and symptomatogenic zone.

  4. Prosthetic

    Directory of Open Access Journals (Sweden)

    Pokpong Amornvit

    2014-01-01

    Full Text Available Ocular trauma can be caused by road traffic accidents, falls, assaults, or work-related accidents. Enucleation is often indicated after ocular injury or for the treatment of intraocular tumors, severe ocular infections, and painful blind eyes. Rehabilitation of an enucleated socket without an intraocular implant or with an inappropriately sized implant can result in superior sulcus deepening, enophthalmos, ptosis, ectropion, and lower lid laxity, which are collectively known as post-enucleation socket syndrome. This clinical report describes the rehabilitation of post-enucleation socket syndrome with a modified ocular prosthesis. Modifications to the ocular prosthesis were performed to correct the ptosis, superior sulcus deepening, and enophthalmos. The rehabilitation procedure produced satisfactory results.

  5. A visual pathway links brain structures active during magnetic compass orientation in migratory birds.

    Directory of Open Access Journals (Sweden)

    Dominik Heyers

    Full Text Available The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, "Cluster N", show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds "see" the reference compass direction provided by the geomagnetic field.

  6. A visual pathway links brain structures active during magnetic compass orientation in migratory birds.

    Science.gov (United States)

    Heyers, Dominik; Manns, Martina; Luksch, Harald; Güntürkün, Onur; Mouritsen, Henrik

    2007-09-26

    The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, "Cluster N", show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds "see" the reference compass direction provided by the geomagnetic field.

  7. Attention Sharpens the Distinction between Expected and Unexpected Percepts in the Visual Brain

    OpenAIRE

    Jiang, J; Summerfield, C.; Egner, T.

    2013-01-01

    Attention, the prioritization of goal-relevant stimuli, and expectation, the modulation of stimulus processing by probabilistic context, represent the two main endogenous determinants of visual cognition. Neural selectivity in visual cortex is enhanced for both attended and expected stimuli, but the functional relationship between these mechanisms is poorly understood. Here, we adjudicated between two current hypotheses of how attention relates to predictive processing, namely, that attention...

  8. Molecular Evidence for Convergence and Parallelism in Evolution of Complex Brains of Cephalopod Molluscs: Insights from Visual Systems.

    Science.gov (United States)

    Yoshida, M A; Ogura, A; Ikeo, K; Shigeno, S; Moritaki, T; Winters, G C; Kohn, A B; Moroz, L L

    2015-12-01

    Coleoid cephalopods show remarkable evolutionary convergence with vertebrates in their neural organization, including (1) eyes and visual system with optic lobes, (2) specialized parts of the brain controlling learning and memory, such as vertical lobes, and (3) unique vasculature supporting such complexity of the central nervous system. We performed deep sequencing of eye transcriptomes of pygmy squids (Idiosepius paradoxus) and chambered nautiluses (Nautilus pompilius) to decipher the molecular basis of convergent evolution in cephalopods. RNA-seq was complemented by in situ hybridization to localize the expression of selected genes. We found three types of genomic innovations in the evolution of complex brains: (1) recruitment of novel genes into morphogenetic pathways, (2) recombination of various coding and regulatory regions of different genes, often called "evolutionary tinkering" or "co-option", and (3) duplication and divergence of genes. Massive recruitment of novel genes occurred in the evolution of the "camera" eye from nautilus' "pinhole" eye. We also showed that the type-2 co-option of transcription factors played important roles in the evolution of the lens and visual neurons. In summary, the cephalopod convergent morphological evolution of the camera eyes was driven by a mosaic of all types of gene recruitments. In addition, our analysis revealed unexpected variations of squids' opsins, retinochromes, and arrestins, providing more detailed information, valuable for further research on intra-ocular and extra-ocular photoreception of the cephalopods.

  9. Autoradiographic visualization of insulin-like growth factor-II receptors in rat brain

    International Nuclear Information System (INIS)

    The documented presence of IGF-II in brain and CSF prompted us to investigate the distribution of receptors for IGF-II in rat brain slices. Human 125-I-IGF-II (10 pM) was incubated for 16 hrs at 40C with slide-mounted rat brain slices in the absence and presence of unlabeled human IGF-II (67 nM) or human insulin (86 nM). Slides were washed, dried, and exposed to X-ray film for 4-7 days. The results showed dense labeling in the granular layers of the olfactory bulbs, deep layers of the cerebral cortex, pineal gland, anterior pituitary, hippocampus (pyramidal cells CA1-CA2 and dentate gyrus), and the granule cell layers of the cerebellum. Unlabeled IGF-II eliminated most of the binding of these brain regions while insulin produced only a minimal reduction in the amount of 125I-IGF-II bound. These results indicate that a specific neural receptor for IGS-II is uniquely distributed in rat brain tissue and supports the notion that this peptide might play an important role in normal neuronal functioning

  10. Compass Cells in the Brain of an Insect Are Sensitive to Novel Events in the Visual World.

    Science.gov (United States)

    Bockhorst, Tobias; Homberg, Uwe

    2015-01-01

    The central complex of the insect brain comprises a group of neuropils involved in spatial orientation and memory. In fruit flies it mediates place learning based on visual landmarks and houses neurons that encode the orientation for goal-directed locomotion, based on landmarks and self-motion cues for angular path-integration. In desert locusts, the central complex holds a compass-like representation of head directions, based on the polarization pattern of skylight. Through intracellular recordings from immobilized locusts, we investigated whether sky compass neurons of the central complex also represent the position or any salient feature of possible landmarks, in analogy to the observations in flies. Neurons showed strongest responses to the novel appearance of a small moving square, but we found no evidence for a topographic representation of object positions. Responses to an individual square were independent of direction of motion and trajectory, but showed rapid adaptation to successive stimulation, unaffected by changing the direction of motion. Responses reappeared, however, if the moving object changed its trajectory or if it suddenly reversed moving direction against the movement of similar objects that make up a coherent background-flow as induced by ego-motion. Response amplitudes co-varied with the precedent state of dynamic background activity, a phenomenon that has been related to attention-dependent saliency coding in neurons of the mammalian primary visual cortex. The data show that neurons of the central complex of the locust brain are visually bimodal, signaling sky compass direction and the novelty character of moving objects. These response properties might serve to attune compass-aided locomotor control to unexpected events in the environment. The difference to data obtained in fruit flies might relate to differences in the lifestyle of landmark learners (fly) and compass navigators (locust), point to the existence of parallel networks for

  11. Effect of visual experience on structural organization of the human brain: A voxel based morphometric study using DARTEL

    International Nuclear Information System (INIS)

    Objective: To investigate structural reorganization in the brain with differential visual experience using Voxel-Based Morphometry with Diffeomorphic Anatomic Registration Through Exponentiated Lie algebra algorithm (DARTEL) approach. Materials and methods: High resolution structural MR images were taken in fifteen normal sighted healthy controls, thirteen totally blind subjects and six partial blind subjects. The analysis was carried out using SPM8 software on MATLAB 7.6.0 platform. Results: VBM study revealed gray matter volume atrophy in the cerebellum and left inferior parietal cortex in total blind subjects and in left inferior parietal cortex, right caudate nucleus, and left primary visual cortex in partial blind subjects as compared to controls. White matter volume loss was found in calcarine gyrus in total blind subjects and Thlamus-somatosensory region in partially blind subjects as compared to controls. Besides, an increase in Gray Matter volume was also found in left middle occipital and middle frontal gyrus and right entorhinal cortex, and an increase in White Matter volume was found in superior frontal gyrus, left middle temporal gyrus and right Heschl's gyrus in totally blind subjects as compared to controls. Comparison between total and partial blind subjects revealed a greater Gray Matter volume in left cerebellum of partial blinds and left Brodmann area 18 of total blind subjects. Conclusion: Results suggest that, loss of vision at an early age can induce significant structural reorganization on account of the loss of visual input. These plastic changes are different in early onset of total blindness as compared to partial blindness

  12. High-resolution brain tumor visualization using three-dimensional x-ray phase contrast tomography.

    Science.gov (United States)

    Pfeiffer, F; Bunk, O; David, C; Bech, M; Le Duc, G; Bravin, A; Cloetens, P

    2007-12-01

    We report on significant advances and new results concerning a recently developed method for grating-based hard x-ray phase tomography. We demonstrate how the soft tissue sensitivity of the technique is increased and show in vitro tomographic images of a tumor bearing rat brain sample, without use of contrast agents. In particular, we observe that the brain tumor and the white and gray brain matter structure in a rat's cerebellum are clearly resolved. The results are potentially interesting from a clinical point of view, since a similar approach using three transmission gratings can be implemented with more readily available x-ray sources, such as standard x-ray tubes. Moreover, the results open the way to in vivo experiments in the near future. PMID:18029984

  13. A survey of prosthetic eye wearers to investigate mucoid discharge

    Directory of Open Access Journals (Sweden)

    Pine K

    2012-05-01

    Full Text Available Keith Pine1, Brian Sloan2, Joanna Stewart3, Robert J Jacobs11Department of Optometry and Vision Science, 2Department of Ophthalmology, New Zealand National Eye Centre, 3Section of Epidemiology and Biostatistics, School of Population Health, University of Auckland, Auckland, New ZealandBackground: This study aimed to better understand the causes and treatments of mucoid discharge associated with prosthetic eye wear by reviewing the literature and surveying anophthalmic patients.Methods: An anonymous questionnaire was completed by 429 prosthetic eye wearers who used visual analog scales to self-measure their discharge experience for four discharge characteristics: frequency, color, volume, and viscosity. These characteristics were analyzed with age, ethnicity, years wearing a prosthesis, eye loss cause, removal and cleaning regimes, hand-washing behavior, age of current prosthesis, and professional repolishing regimes as explanatory variables. Eighteen ocularists’ Web sites containing comments on the cause and treatment of discharge were surveyed.Results: Associations were found between discharge frequency and cleaning regimes with more frequent cleaning accompanying more frequent discharge. Color was associated with years of wearing and age, with more years of wearing and older people having less colored discharge. Volume was associated with cleaning regimes with more frequent cleaners having more volume. Viscosity was associated with cleaning regimes and years of wearing with more frequent cleaning and shorter wearing time accompanying more viscous discharge. No associations were found between discharge characteristics and ethnicity, eye loss cause, hand washing, age of current prosthesis, or repolishing regimes. Forty-seven percent of ocularists’ Web sites advised that discharge was caused by surface deposits on the prosthesis, 29% by excessive handling of the prosthesis, and 24% by other causes.Conclusions: A standardized treatment

  14. 3D-visualization of intracranial vessels and brain anatomy in magnetic resonance imaging

    International Nuclear Information System (INIS)

    This paper describes a 3D-image processing approach to generate a combination display of intracranial vessels and adjacent brain tissue surfaces in magnetic resonance imaging (MRI). The algorithm is based on the ray-tracing principle and may be regarded as a union of the techniques of surface integration and maximum intensity projection (MIP). Measurement methods and preprocessing steps of acquisition of a flow-compensated vessel dataset and a T1 weighted tissue volume with isolated brain with equal partitioning are described. The method is intended as a tool for the optimization of neurosurgical planning

  15. DME Prosthetics Orthotics, and Supplies Fee Schedule

    Data.gov (United States)

    U.S. Department of Health & Human Services — Durable Medical Equipment, Prosthetics-Orthotics, and Supplies Fee Schedule. The list contains the fee schedule amounts, floors, and ceilings for all procedure...

  16. Advanced prosthetic techniques for below knee amputations.

    Science.gov (United States)

    Staats, T B

    1985-02-01

    Recent advances in the evaluation of the amputation stump, the materials that are available for prosthetic application, techniques of improving socket fit, and prosthetic finishings promise to dramatically improve amputee function. Precision casting techniques for providing optimal fit of the amputation stump using materials such as alginate are described. The advantages of transparent check sockets for fitting the complicated amputation stump are described. Advances in research that promise to provide more functional prosthetic feet and faster and more reliable socket molding are the use of CAD-CAM (computer aided design-computer aided manufacturing) and the use of gait analysis techniques to aid in the alignment of the prosthesis after socket fitting. Finishing techniques to provide a more natural appearing prosthesis are described. These advances will gradually spread to the entire prosthetic profession.

  17. Higher Brain Functions Served by the Lowly Rodent Primary Visual Cortex

    Science.gov (United States)

    Gavornik, Jeffrey P.; Bear, Mark F.

    2014-01-01

    It has been more than 50 years since the first description of ocular dominance plasticity--the profound modification of primary visual cortex (V1) following temporary monocular deprivation. This discovery immediately attracted the intense interest of neurobiologists focused on the general question of how experience and deprivation modify the brain…

  18. Differentiation of Brain Tumor Recurrence from Post-Radiotherapy Necrosis with 11C-Methionine PET: Visual Assessment versus Quantitative Assessment.

    Directory of Open Access Journals (Sweden)

    Ryogo Minamimoto

    Full Text Available The aim of this multi-center study was to assess the diagnostic capability of visual assessment in L-methyl-11C-methionine positron emission tomography (MET-PET for differentiating a recurrent brain tumor from radiation-induced necrosis after radiotherapy, and to compare it to the accuracy of quantitative analysis.A total of 73 brain lesions (glioma: 31, brain metastasis: 42 in 70 patients who underwent MET-PET were included in this study. Visual analysis was performed by comparison of MET uptake in the brain lesion with MET uptake in one of four regions (around the lesion, contralateral frontal lobe, contralateral area, and contralateral cerebellar cortex. The concordance rate and logistic regression analysis were used to evaluate the diagnostic ability of visual assessment. Receiver-operating characteristic curve analysis was used to compare visual assessment with quantitative assessment based on the lesion-to-normal (L/N ratio of MET uptake.Interobserver and intraobserver κ-values were highest at 0.657 and 0.714, respectively, when assessing MET uptake in the lesion compared to that in the contralateral cerebellar cortex. Logistic regression analysis showed that assessing MET uptake in the contralateral cerebellar cortex with brain metastasis was significantly related to the final result. The highest area under the receiver-operating characteristic curve (AUC with visual assessment for brain metastasis was 0.85, showing no statistically significant difference with L/Nmax of the contralateral brain (AUC = 0.89 or with L/Nmean of the contralateral cerebellar cortex (AUC = 0.89, which were the areas that were the highest in the quantitative assessment. For evaluation of gliomas, no specific candidate was confirmed among the four areas used in visual assessment, and no significant difference was seen between visual assessment and quantitative assessment.The visual assessment showed no significant difference from quantitative assessment of MET

  19. Holistic face categorization in higher-level cortical visual areas of the normal and prosopagnosic brain: towards a non-hierarchical view of face perception

    Directory of Open Access Journals (Sweden)

    Bruno Rossion

    2011-01-01

    Full Text Available How a visual stimulus is initially categorized as a face in a network of human brain areas remains largely unclear. Hierarchical neuro-computational models of face perception assume that the visual stimulus is first decomposed in local parts in lower order visual areas. These parts would then be combined into a global representation in higher order face-sensitive areas of the occipito-temporal cortex. Here we tested this view in fMRI with visual stimuli that are categorized as faces based on their global configuration rather than their local parts (2-tones Mooney figures and Arcimboldo’s facelike paintings. Compared to the same inverted visual stimuli that are not categorized as faces, these stimuli activated the right middle fusiform gyrus (Fusiform face area, FFA and superior temporal sulcus (pSTS, with no significant activation in the posteriorly located inferior occipital gyrus (i.e., no occipital face area, OFA. This observation is strengthened by behavioral and neural evidence for normal face categorization of these stimuli in a brain-damaged prosopagnosic patient (PS whose intact right middle fusiform gyrus and superior temporal sulcus are devoid of any potential face-sensitive inputs from the lesioned right inferior occipital cortex. Together, these observations indicate that face-preferential activation may emerge in higher order visual areas of the right hemisphere without any face-preferential inputs from lower order visual areas, supporting a non-hierarchical view of face perception in the visual cortex.

  20. Large Scale Functional Brain Networks Underlying Temporal Integration of Audio-Visual Speech Perception: An EEG Study

    Science.gov (United States)

    Kumar, G. Vinodh; Halder, Tamesh; Jaiswal, Amit K.; Mukherjee, Abhishek; Roy, Dipanjan; Banerjee, Arpan

    2016-01-01

    Observable lip movements of the speaker influence perception of auditory speech. A classical example of this influence is reported by listeners who perceive an illusory (cross-modal) speech sound (McGurk-effect) when presented with incongruent audio-visual (AV) speech stimuli. Recent neuroimaging studies of AV speech perception accentuate the role of frontal, parietal, and the integrative brain sites in the vicinity of the superior temporal sulcus (STS) for multisensory speech perception. However, if and how does the network across the whole brain participates during multisensory perception processing remains an open question. We posit that a large-scale functional connectivity among the neural population situated in distributed brain sites may provide valuable insights involved in processing and fusing of AV speech. Varying the psychophysical parameters in tandem with electroencephalogram (EEG) recordings, we exploited the trial-by-trial perceptual variability of incongruent audio-visual (AV) speech stimuli to identify the characteristics of the large-scale cortical network that facilitates multisensory perception during synchronous and asynchronous AV speech. We evaluated the spectral landscape of EEG signals during multisensory speech perception at varying AV lags. Functional connectivity dynamics for all sensor pairs was computed using the time-frequency global coherence, the vector sum of pairwise coherence changes over time. During synchronous AV speech, we observed enhanced global gamma-band coherence and decreased alpha and beta-band coherence underlying cross-modal (illusory) perception compared to unisensory perception around a temporal window of 300–600 ms following onset of stimuli. During asynchronous speech stimuli, a global broadband coherence was observed during cross-modal perception at earlier times along with pre-stimulus decreases of lower frequency power, e.g., alpha rhythms for positive AV lags and theta rhythms for negative AV lags. Thus

  1. A Tool for Interactive Data Visualization: Application to Over 10,000 Brain Imaging and Phantom MRI Data Sets.

    Science.gov (United States)

    Panta, Sandeep R; Wang, Runtang; Fries, Jill; Kalyanam, Ravi; Speer, Nicole; Banich, Marie; Kiehl, Kent; King, Margaret; Milham, Michael; Wager, Tor D; Turner, Jessica A; Plis, Sergey M; Calhoun, Vince D

    2016-01-01

    In this paper we propose a web-based approach for quick visualization of big data from brain magnetic resonance imaging (MRI) scans using a combination of an automated image capture and processing system, nonlinear embedding, and interactive data visualization tools. We draw upon thousands of MRI scans captured via the COllaborative Imaging and Neuroinformatics Suite (COINS). We then interface the output of several analysis pipelines based on structural and functional data to a t-distributed stochastic neighbor embedding (t-SNE) algorithm which reduces the number of dimensions for each scan in the input data set to two dimensions while preserving the local structure of data sets. Finally, we interactively display the output of this approach via a web-page, based on data driven documents (D3) JavaScript library. Two distinct approaches were used to visualize the data. In the first approach, we computed multiple quality control (QC) values from pre-processed data, which were used as inputs to the t-SNE algorithm. This approach helps in assessing the quality of each data set relative to others. In the second case, computed variables of interest (e.g., brain volume or voxel values from segmented gray matter images) were used as inputs to the t-SNE algorithm. This approach helps in identifying interesting patterns in the data sets. We demonstrate these approaches using multiple examples from over 10,000 data sets including (1) quality control measures calculated from phantom data over time, (2) quality control data from human functional MRI data across various studies, scanners, sites, (3) volumetric and density measures from human structural MRI data across various studies, scanners and sites. Results from (1) and (2) show the potential of our approach to combine t-SNE data reduction with interactive color coding of variables of interest to quickly identify visually unique clusters of data (i.e., data sets with poor QC, clustering of data by site) quickly. Results from

  2. 3D-reconstructions and virtual 4D-visualization to study metamorphic brain development in the sphinx moth Manduca sexta

    Directory of Open Access Journals (Sweden)

    Wolf Huetteroth

    2010-03-01

    Full Text Available During metamorphosis, the transition from the larva to the adult, the insect brain undergoes considerable remodeling: New neurons are integrated while larval neurons are remodeled or eliminated. One well acknowledged model to study metamorphic brain development is the sphinx moth Manduca sexta. To further understand mechanisms involved in the metamorphic transition of the brain we generated a 3D standard brain based on selected brain areas of adult females and 3D reconstructed the same areas during defined stages of pupal development. Selected brain areas include for example mushroom bodies, central complex, antennal- and optic lobes. With this approach we eventually want to quantify developmental changes in neuropilar architecture, but also quantify changes in the neuronal complement and monitor the development of selected neuronal populations. Furthermore, we used a modeling software (Cinema 4D to create a virtual 4D brain, morphing through its developmental stages. Thus the didactical advantages of 3D visualization are expanded to better comprehend complex processes of neuropil formation and remodeling during development. To obtain datasets of the M. sexta brain areas, we stained whole brains with an antiserum against the synaptic vesicle protein synapsin. Such labeled brains were then scanned with a confocal laser scanning microscope and selected neuropils were reconstructed with the 3D software AMIRA 4.1.

  3. Assessment of sexual orientation using the hemodynamic brain response to visual sexual stimuli

    DEFF Research Database (Denmark)

    Ponseti, Jorge; Granert, Oliver; Jansen, Olav;

    2009-01-01

    INTRODUCTION: The assessment of sexual orientation is of importance to the diagnosis and treatment of sex offenders and paraphilic disorders. Phallometry is considered gold standard in objectifying sexual orientation, yet this measurement has been criticized because of its intrusiveness and limited...... response patterns of the brain to sexual stimuli contained sufficient information to predict individual sexual orientation with high accuracy. These results suggest that fMRI-based classification methods hold promise for the diagnosis of paraphilic disorders (e.g., pedophilia)....

  4. Single-trial detection of visual evoked potentials by common spatial patterns and wavelet filtering for brain-computer interface.

    Science.gov (United States)

    Tu, Yiheng; Huang, Gan; Hung, Yeung Sam; Hu, Li; Hu, Yong; Zhang, Zhiguo

    2013-01-01

    Event-related potentials (ERPs) are widely used in brain-computer interface (BCI) systems as input signals conveying a subject's intention. A fast and reliable single-trial ERP detection method can be used to develop a BCI system with both high speed and high accuracy. However, most of single-trial ERP detection methods are developed for offline EEG analysis and thus have a high computational complexity and need manual operations. Therefore, they are not applicable to practical BCI systems, which require a low-complexity and automatic ERP detection method. This work presents a joint spatial-time-frequency filter that combines common spatial patterns (CSP) and wavelet filtering (WF) for improving the signal-to-noise (SNR) of visual evoked potentials (VEP), which can lead to a single-trial ERP-based BCI.

  5. Investigating the role of combined acoustic-visual feedback in one-dimensional synchronous brain computer interfaces, a preliminary study

    Directory of Open Access Journals (Sweden)

    Gargiulo GD

    2012-09-01

    Full Text Available Gaetano D Gargiulo,1–3 Armin Mohamed,1 Alistair L McEwan,1 Paolo Bifulco,2 Mario Cesarelli,2 Craig T Jin,1 Mariano Ruffo,2 Jonathan Tapson,3 André van Schaik31School of Electrical and Information Engineering, The University of Sydney, New South Wales, Australia; 2Dipartimento di Ingegneria Elettronica e delle Telecomunicazioni "Federico II" University of Naples, Naples, Italy; 3BENS Laboratory, MARCS Institute, The University of Western Sydney, New South Wales, AustraliaAbstract: Feedback plays an important role when learning to use a brain computer interface (BCI, particularly in the case of synchronous feedback that relies on the interaction subject. In this preliminary study, we investigate the role of combined auditory-visual feedback during synchronous µ rhythm-based BCI sessions to help the subject to remain focused on the selected imaginary task. This new combined feedback, now integrated within the general purpose BCI2000 software, has been tested on eight untrained and three trained subjects during a monodimensional left-right control task. In order to reduce the setup burden and maximize subject comfort, an electroencephalographic device suitable for dry electrodes that required no skin preparation was used. Quality and index of improvement was evaluated based on a personal self-assessment questionnaire from each subject and quantitative data based on subject performance. Results for this preliminary study show that the combined feedback was well tolerated by the subjects and improved performance in 75% of the naïve subjects compared with visual feedback alone.Keywords: brain computer interface, dry electrodes, subject feedback

  6. Reliability-based automatic repeat request for short code modulation visual evoked potentials in brain computer interfaces.

    Science.gov (United States)

    Sato, Jun-Ichi; Washizawa, Yoshikazu

    2015-08-01

    We propose two methods to improve code modulation visual evoked potential brain computer interfaces (cVEP BCIs). Most of BCIs average brain signals from several trials in order to improve the classification performance. The number of averaging defines the trade-off between input speed and accuracy, and the optimal averaging number depends on individual, signal acquisition system, and so forth. Firstly, we propose a novel dynamic method to estimate the averaging number for cVEP BCIs. The proposed method is based on the automatic repeat request (ARQ) that is used in communication systems. The existing cVEP BCIs employ rather longer code, such as 63-bit M-sequence. The code length also defines the trade-off between input speed and accuracy. Since the reliability of the proposed BCI can be controlled by the proposed ARQ method, we introduce shorter codes, 32-bit M-sequence and the Kasami-sequence. Thanks to combine the dynamic averaging number estimation method and the shorter codes, the proposed system exhibited higher information transfer rate compared to existing cVEP BCIs.

  7. Cytosolic NADH-NAD+ Redox Visualized in Brain Slices by Two-Photon Fluorescence Lifetime Biosensor Imaging

    Science.gov (United States)

    Mongeon, Rebecca; Venkatachalam, Veena

    2016-01-01

    Abstract Aim: Cytosolic NADH-NAD+ redox state is central to cellular metabolism and a valuable indicator of glucose and lactate metabolism in living cells. Here we sought to quantitatively determine NADH-NAD+ redox in live cells and brain tissue using a fluorescence lifetime imaging of the genetically-encoded single-fluorophore biosensor Peredox. Results: We show that Peredox exhibits a substantial change in its fluorescence lifetime over its sensing range of NADH-NAD+ ratio. This allows changes in cytosolic NADH redox to be visualized in living cells using a two-photon scanning microscope with fluorescence lifetime imaging capabilities (2p-FLIM), using time-correlated single photon counting. Innovation: Because the lifetime readout is absolutely calibrated (in nanoseconds) and is independent of sensor concentration, we demonstrate that quantitative assessment of NADH redox is possible using a single fluorophore biosensor. Conclusion: Imaging of the sensor in mouse hippocampal brain slices reveals that astrocytes are typically much more reduced (with higher NADH:NAD+ ratio) than neurons under basal conditions, consistent with the hypothesis that astrocytes are more glycolytic than neurons. Antioxid. Redox Signal. 25, 553–563. PMID:26857245

  8. Visual Sexual Stimuli-Cue or Reward? A Perspective for Interpreting Brain Imaging Findings on Human Sexual Behaviors.

    Science.gov (United States)

    Gola, Mateusz; Wordecha, Małgorzata; Marchewka, Artur; Sescousse, Guillaume

    2016-01-01

    There is an increasing number of neuroimaging studies using visual sexual stimuli (VSS), especially within the emerging field of research on compulsive sexual behaviors (CSB). A central question in this field is whether behaviors such as excessive pornography consumption share common brain mechanisms with widely studied substance and behavioral addictions. Depending on how VSS are conceptualized, different predictions can be formulated within the frameworks of Reinforcement Learning or Incentive Salience Theory, where a crucial distinction is made between conditioned and unconditioned stimuli (related to reward anticipation vs. reward consumption, respectively). Surveying 40 recent human neuroimaging studies we show existing ambiguity about the conceptualization of VSS. Therefore, we feel that it is important to address the question of whether VSS should be considered as conditioned stimuli (cue) or unconditioned stimuli (reward). Here we present our own perspective, which is that in most laboratory settings VSS play a role of reward, as evidenced by: (1) experience of pleasure while watching VSS, possibly accompanied by genital reaction; (2) reward-related brain activity correlated with these pleasurable feelings in response to VSS; (3) a willingness to exert effort to view VSS similarly as for other rewarding stimuli such as money; and (4) conditioning for cues predictive of VSS. We hope that this perspective article will initiate a scientific discussion on this important and overlooked topic and increase attention for appropriate interpretations of results of human neuroimaging studies using VSS. PMID:27574507

  9. Visual Sexual Stimuli—Cue or Reward? A Perspective for Interpreting Brain Imaging Findings on Human Sexual Behaviors

    Science.gov (United States)

    Gola, Mateusz; Wordecha, Małgorzata; Marchewka, Artur; Sescousse, Guillaume

    2016-01-01

    There is an increasing number of neuroimaging studies using visual sexual stimuli (VSS), especially within the emerging field of research on compulsive sexual behaviors (CSB). A central question in this field is whether behaviors such as excessive pornography consumption share common brain mechanisms with widely studied substance and behavioral addictions. Depending on how VSS are conceptualized, different predictions can be formulated within the frameworks of Reinforcement Learning or Incentive Salience Theory, where a crucial distinction is made between conditioned and unconditioned stimuli (related to reward anticipation vs. reward consumption, respectively). Surveying 40 recent human neuroimaging studies we show existing ambiguity about the conceptualization of VSS. Therefore, we feel that it is important to address the question of whether VSS should be considered as conditioned stimuli (cue) or unconditioned stimuli (reward). Here we present our own perspective, which is that in most laboratory settings VSS play a role of reward, as evidenced by: (1) experience of pleasure while watching VSS, possibly accompanied by genital reaction; (2) reward-related brain activity correlated with these pleasurable feelings in response to VSS; (3) a willingness to exert effort to view VSS similarly as for other rewarding stimuli such as money; and (4) conditioning for cues predictive of VSS. We hope that this perspective article will initiate a scientific discussion on this important and overlooked topic and increase attention for appropriate interpretations of results of human neuroimaging studies using VSS. PMID:27574507

  10. A Proposed Treatment for Visual Field Loss caused by Traumatic Brain Injury using Interactive Visuotactile Virtual Environment

    Science.gov (United States)

    Farkas, Attila J.; Hajnal, Alen; Shiratuddin, Mohd F.; Szatmary, Gabriella

    In this paper, we propose a novel approach of using interactive virtual environment technology in Vision Restoration Therapy caused by Traumatic Brain Injury. We called the new system Interactive Visuotactile Virtual Environment and it holds a promise of expanding the scope of already existing rehabilitation techniques. Traditional vision rehabilitation methods are based on passive psychophysical training procedures, and can last up to six months before any modest improvements can be seen in patients. A highly immersive and interactive virtual environment will allow the patient to practice everyday activities such as object identification and object manipulation through the use 3D motion sensoring handheld devices such data glove or the Nintendo Wiimote. Employing both perceptual and action components in the training procedures holds the promise of more efficient sensorimotor rehabilitation. Increased stimulation of visual and sensorimotor areas of the brain should facilitate a comprehensive recovery of visuomotor function by exploiting the plasticity of the central nervous system. Integrated with a motion tracking system and an eye tracking device, the interactive virtual environment allows for the creation and manipulation of a wide variety of stimuli, as well as real-time recording of hand-, eye- and body movements and coordination. The goal of the project is to design a cost-effective and efficient vision restoration system.

  11. Visual Sexual Stimuli-Cue or Reward? A Perspective for Interpreting Brain Imaging Findings on Human Sexual Behaviors.

    Science.gov (United States)

    Gola, Mateusz; Wordecha, Małgorzata; Marchewka, Artur; Sescousse, Guillaume

    2016-01-01

    There is an increasing number of neuroimaging studies using visual sexual stimuli (VSS), especially within the emerging field of research on compulsive sexual behaviors (CSB). A central question in this field is whether behaviors such as excessive pornography consumption share common brain mechanisms with widely studied substance and behavioral addictions. Depending on how VSS are conceptualized, different predictions can be formulated within the frameworks of Reinforcement Learning or Incentive Salience Theory, where a crucial distinction is made between conditioned and unconditioned stimuli (related to reward anticipation vs. reward consumption, respectively). Surveying 40 recent human neuroimaging studies we show existing ambiguity about the conceptualization of VSS. Therefore, we feel that it is important to address the question of whether VSS should be considered as conditioned stimuli (cue) or unconditioned stimuli (reward). Here we present our own perspective, which is that in most laboratory settings VSS play a role of reward, as evidenced by: (1) experience of pleasure while watching VSS, possibly accompanied by genital reaction; (2) reward-related brain activity correlated with these pleasurable feelings in response to VSS; (3) a willingness to exert effort to view VSS similarly as for other rewarding stimuli such as money; and (4) conditioning for cues predictive of VSS. We hope that this perspective article will initiate a scientific discussion on this important and overlooked topic and increase attention for appropriate interpretations of results of human neuroimaging studies using VSS.

  12. Investigating the role of combined acoustic-visual feedback in one-dimensional synchronous brain computer interfaces, a preliminary study

    Science.gov (United States)

    Gargiulo, Gaetano D; Mohamed, Armin; McEwan, Alistair L; Bifulco, Paolo; Cesarelli, Mario; Jin, Craig T; Ruffo, Mariano; Tapson, Jonathan; van Schaik, André

    2012-01-01

    Feedback plays an important role when learning to use a brain computer interface (BCI), particularly in the case of synchronous feedback that relies on the interaction subject. In this preliminary study, we investigate the role of combined auditory-visual feedback during synchronous μ rhythm-based BCI sessions to help the subject to remain focused on the selected imaginary task. This new combined feedback, now integrated within the general purpose BCI2000 software, has been tested on eight untrained and three trained subjects during a monodimensional left-right control task. In order to reduce the setup burden and maximize subject comfort, an electroencephalographic device suitable for dry electrodes that required no skin preparation was used. Quality and index of improvement was evaluated based on a personal self-assessment questionnaire from each subject and quantitative data based on subject performance. Results for this preliminary study show that the combined feedback was well tolerated by the subjects and improved performance in 75% of the naïve subjects compared with visual feedback alone. PMID:23152713

  13. [A wireless smart home system based on brain-computer interface of steady state visual evoked potential].

    Science.gov (United States)

    Zhao, Li; Xing, Xiao; Guo, Xuhong; Liu, Zehua; He, Yang

    2014-10-01

    Brain-computer interface (BCI) system is a system that achieves communication and control among humans and computers and other electronic equipment with the electroencephalogram (EEG) signals. This paper describes the working theory of the wireless smart home system based on the BCI technology. We started to get the steady-state visual evoked potential (SSVEP) using the single chip microcomputer and the visual stimulation which composed by LED lamp to stimulate human eyes. Then, through building the power spectral transformation on the LabVIEW platform, we processed timely those EEG signals under different frequency stimulation so as to transfer them to different instructions. Those instructions could be received by the wireless transceiver equipment to control the household appliances and to achieve the intelligent control towards the specified devices. The experimental results showed that the correct rate for the 10 subjects reached 100%, and the control time of average single device was 4 seconds, thus this design could totally achieve the original purpose of smart home system.

  14. Children with reading disability show brain differences in effective connectivity for visual, but not auditory word comprehension.

    Directory of Open Access Journals (Sweden)

    Li Liu

    Full Text Available BACKGROUND: Previous literature suggests that those with reading disability (RD have more pronounced deficits during semantic processing in reading as compared to listening comprehension. This discrepancy has been supported by recent neuroimaging studies showing abnormal activity in RD during semantic processing in the visual but not in the auditory modality. Whether effective connectivity between brain regions in RD could also show this pattern of discrepancy has not been investigated. METHODOLOGY/PRINCIPAL FINDINGS: Children (8- to 14-year-olds were given a semantic task in the visual and auditory modality that required an association judgment as to whether two sequentially presented words were associated. Effective connectivity was investigated using Dynamic Causal Modeling (DCM on functional magnetic resonance imaging (fMRI data. Bayesian Model Selection (BMS was used separately for each modality to find a winning family of DCM models separately for typically developing (TD and RD children. BMS yielded the same winning family with modulatory effects on bottom-up connections from the input regions to middle temporal gyrus (MTG and inferior frontal gyrus(IFG with inconclusive evidence regarding top-down modulations. Bayesian Model Averaging (BMA was thus conducted across models in this winning family and compared across groups. The bottom-up effect from the fusiform gyrus (FG to MTG rather than the top-down effect from IFG to MTG was stronger in TD compared to RD for the visual modality. The stronger bottom-up influence in TD was only evident for related word pairs but not for unrelated pairs. No group differences were noted in the auditory modality. CONCLUSIONS/SIGNIFICANCE: This study revealed a modality-specific deficit for children with RD in bottom-up effective connectivity from orthographic to semantic processing regions. There were no group differences in connectivity from frontal regions, suggesting that the core deficit in RD is not

  15. Effect of visual experience on structural organization of the human brain: A voxel based morphometric study using DARTEL

    Energy Technology Data Exchange (ETDEWEB)

    Modi, Shilpi, E-mail: modi_shilpi@yahoo.co.in [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India); Bhattacharya, Manisha, E-mail: manishab10@gmail.com [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India); Singh, Namita, E-mail: namita23m@gmail.com [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India); Tripathi, Rajendra Prasad, E-mail: director@inmas.drdo.in [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India); Khushu, Subash, E-mail: skhushu@yahoo.com [NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (DRDO), Lucknow Road, Timarpur, Delhi (India)

    2012-10-15

    Objective: To investigate structural reorganization in the brain with differential visual experience using Voxel-Based Morphometry with Diffeomorphic Anatomic Registration Through Exponentiated Lie algebra algorithm (DARTEL) approach. Materials and methods: High resolution structural MR images were taken in fifteen normal sighted healthy controls, thirteen totally blind subjects and six partial blind subjects. The analysis was carried out using SPM8 software on MATLAB 7.6.0 platform. Results: VBM study revealed gray matter volume atrophy in the cerebellum and left inferior parietal cortex in total blind subjects and in left inferior parietal cortex, right caudate nucleus, and left primary visual cortex in partial blind subjects as compared to controls. White matter volume loss was found in calcarine gyrus in total blind subjects and Thlamus-somatosensory region in partially blind subjects as compared to controls. Besides, an increase in Gray Matter volume was also found in left middle occipital and middle frontal gyrus and right entorhinal cortex, and an increase in White Matter volume was found in superior frontal gyrus, left middle temporal gyrus and right Heschl's gyrus in totally blind subjects as compared to controls. Comparison between total and partial blind subjects revealed a greater Gray Matter volume in left cerebellum of partial blinds and left Brodmann area 18 of total blind subjects. Conclusion: Results suggest that, loss of vision at an early age can induce significant structural reorganization on account of the loss of visual input. These plastic changes are different in early onset of total blindness as compared to partial blindness.

  16. Fully Online Multicommand Brain-Computer Interface with Visual Neurofeedback Using SSVEP Paradigm

    Directory of Open Access Journals (Sweden)

    Hovagim Bakardjian

    2007-07-01

    Full Text Available We propose a new multistage procedure for a real-time brain-machine/computer interface (BCI. The developed system allows a BCI user to navigate a small car (or any other object on the computer screen in real time, in any of the four directions, and to stop it if necessary. Extensive experiments with five young healthy subjects confirmed the high performance of the proposed online BCI system. The modular structure, high speed, and the optimal frequency band characteristics of the BCI platform are features which allow an extension to a substantially higher number of commands in the near future.

  17. Real-time fMRI brain-computer interface: Development of a "motivational feedback" subsystem for the regulation of visual cue reactivity

    Directory of Open Access Journals (Sweden)

    Moses O. Sokunbi

    2014-11-01

    Full Text Available Here we present a novel neurofeedback subsystem for the presentation of motivationally relevant visual feedback during the self-regulation of functional brain activation. Our motivational neurofeedback approach uses functional magnetic resonance imaging (fMRI signals elicited by visual cues (pictures and related to motivational processes such as craving or hunger. The visual feedback subsystem provides simultaneous feedback through these images as their size corresponds to the magnitude of fMRI signal change from a target brain area. During self-regulation of cue-evoked brain responses, decreases and increases in picture size thus provide real motivational consequences in terms of cue approach versus cue avoidance, which increases face validity of the approach in applied settings. Further, the outlined approach comprises of neurofeedback (regulation and mirror runs that allow to control for non-specific and task-unrelated effects, such as habituation or neural adaptation. The approach was implemented in the Python programming language. Pilot data from 10 volunteers showed that participants were able to successfully down-regulate individually defined target areas, demonstrating feasibility of the approach. The newly developed visual feedback subsystem can be integrated into protocols for imaging-based brain-computer interfaces (BCI and may facilitate neurofeedback research and applications into healthy and dysfunctional motivational processes, such food craving or addiction.

  18. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seok Kyun; Kim, Gwang Won; Kang, Heoung Keun; Jeong, Gwang Woo [Chonnam National University, Gwangju (Korea, Republic of); Yang, Jong Chul [Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kim, Seok Kwun [Dong-A University College of Medicine, Busan (Korea, Republic of)

    2012-06-15

    This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with both male and female erotic nude pictures. The sex hormone levels of the postoperative MTF transsexuals were in the normal range of healthy heterosexual females. The brain areas, which were activated by viewing male nude pictures when compared with viewing female nude pictures, included predominantly the cerebellum, hippocampus, putamen, anterior cingulate gyrus, head of caudate nucleus, amygdala, midbrain, thalamus, insula, and body of caudate nucleus. On the other hand, brain activation induced by viewing female nude pictures was predominantly observed in the hypothalamus and the septal area. Our findings suggest that distinct brain activation patterns associated with visual sexual arousal in postoperative MTF transsexuals reflect their sexual orientation to males.

  19. Adaptive prosthetics for the lower extremity.

    Science.gov (United States)

    Carroll, K

    2001-06-01

    The potential for lifestyle recovery is tremendous for most lower extremity amputees. The amazing and ever-expanding array of adaptive prosthetics can help make the devastating loss of amputation more bearable for patients, their families, and their health care team. The new amputee, in a state of shock and grief, does not know what his or her prosthetic options are. It is crucial that the surgeon is knowledgeable about what the patient can have and what the patient needs to ask for. Dana Bowman stated: Ideally, the new amputee should say to their doctor, "I'd like my leg to be lightweight, flexible, durable, comfortable. I want to do sports or I want to ride bikes with my kids." Whatever it is they like to do. I was told I would never be able to wear two dynamic feet and that my sky diving days were over. I said, "Well how do you know? Can't I try?" It took years to find out what I could have and then to find people to help me get it. The prosthetic prescription the physician writes is the patient's gateway to the kind of prosthetics that will enable him or her to pursue the activities of their life. Often, new amputees end up with the bare minimum prosthesis, which can cause problems with comfort and mobility. A poorly designed or badly fitting prosthesis is as disabling as the actual amputation. When the surgeon can help the amputee and his or her family understand what kind of prosthetic choices are available, it establishes an optimistic outlook that is highly beneficial to the entire recovery process physically and mentally. "When I lost my leg, if someone would have told me that I could at least try to run again, that would have meant a lot," said Brian Frasure. "Getting that positive mental attitude is every bit as important as having good medical and prosthetic care." By asking probing questions about the patient's preamputation lifestyle and postamputation goals, the physician can write a prescription for truly adaptive prosthetics. The surgeon should

  20. Prosthetic Valve Thrombosis: Diagnosis and Management.

    Science.gov (United States)

    Garg, Jalaj; Palaniswamy, Chandrasekar; Pinnamaneni, Sowmya; Sarungbam, Judy; Jain, Diwakar

    2016-01-01

    St. Jude mechanical prosthesis is the most commonly used prosthetic device with least valvular complications with excellent hemodynamics. However, prosthetic valve thrombosis is one of the serious complications, with rates between 0.03% and 0.13% per patient-year depending on the type of anticoagulation used and compliance to the therapy. Transthoracic echocardiography (TTE) is the initial screening tool (class I) that would provide clues for the assessment of valvular hemodynamics. Fluoroscopy is an alternate imaging modality for the assessment of mechanical leaflet motion, especially in patients when prosthetic valves are difficult to image on TTE or transesophageal echocardiography. A complete fluoroscopic evaluation of a prosthetic valve includes assessment of valvular motion and structural integrity. Opening and closing angles can be measured fluoroscopically to determine whether a specific valve is functioning properly. We discuss a case of a 91-year-old man with thrombosis of bileaflet mechanical mitral prosthesis that was demonstrated on real-time fluoroscopy (not evident on TTE). An algorithmic approach to diagnosis and management of prosthetic heart valve thrombosis is outlined. PMID:25486519

  1. Classifying prosthetic use via accelerometry in persons with transtibial amputations

    Directory of Open Access Journals (Sweden)

    Morgan T. Redfield, MSEE

    2013-12-01

    Full Text Available Knowledge of how persons with amputation use their prostheses and how this use changes over time may facilitate effective rehabilitation practices and enhance understanding of prosthesis functionality. Perpetual monitoring and classification of prosthesis use may also increase the health and quality of life for prosthetic users. Existing monitoring and classification systems are often limited in that they require the subject to manipulate the sensor (e.g., attach, remove, or reset a sensor, record data over relatively short time periods, and/or classify a limited number of activities and body postures of interest. In this study, a commercially available three-axis accelerometer (ActiLife ActiGraph GT3X+ was used to characterize the activities and body postures of individuals with transtibial amputation. Accelerometers were mounted on prosthetic pylons of 10 persons with transtibial amputation as they performed a preset routine of actions. Accelerometer data was postprocessed using a binary decision tree to identify when the prosthesis was being worn and to classify periods of use as movement (i.e., leg motion such as walking or stair climbing, standing (i.e., standing upright with limited leg motion, or sitting (i.e., seated with limited leg motion. Classifications were compared to visual observation by study researchers. The classifier achieved a mean +/– standard deviation accuracy of 96.6% +/– 3.0%.

  2. Classifying prosthetic use via accelerometry in persons with transtibial amputations.

    Science.gov (United States)

    Redfield, Morgan T; Cagle, John C; Hafner, Brian J; Sanders, Joan E

    2013-01-01

    Knowledge of how persons with amputation use their prostheses and how this use changes over time may facilitate effective rehabilitation practices and enhance understanding of prosthesis functionality. Perpetual monitoring and classification of prosthesis use may also increase the health and quality of life for prosthetic users. Existing monitoring and classification systems are often limited in that they require the subject to manipulate the sensor (e.g., attach, remove, or reset a sensor), record data over relatively short time periods, and/or classify a limited number of activities and body postures of interest. In this study, a commercially available three-axis accelerometer (ActiLife ActiGraph GT3X+) was used to characterize the activities and body postures of individuals with transtibial amputation. Accelerometers were mounted on prosthetic pylons of 10 persons with transtibial amputation as they performed a preset routine of actions. Accelerometer data was postprocessed using a binary decision tree to identify when the prosthesis was being worn and to classify periods of use as movement (i.e., leg motion such as walking or stair climbing), standing (i.e., standing upright with limited leg motion), or sitting (i.e., seated with limited leg motion). Classifications were compared to visual observation by study researchers. The classifier achieved a mean +/- standard deviation accuracy of 96.6% +/- 3.0%.

  3. Modeling Visual Information Processing in Brain: A Computer Vision Point of View and Approach

    CERN Document Server

    Diamant, Emanuel

    2007-01-01

    We live in the Information Age, and information has become a critically important component of our life. The success of the Internet made huge amounts of it easily available and accessible to everyone. To keep the flow of this information manageable, means for its faultless circulation and effective handling have become urgently required. Considerable research efforts are dedicated today to address this necessity, but they are seriously hampered by the lack of a common agreement about "What is information?" In particular, what is "visual information" - human's primary input from the surrounding world. The problem is further aggravated by a long-lasting stance borrowed from the biological vision research that assumes human-like information processing as an enigmatic mix of perceptual and cognitive vision faculties. I am trying to find a remedy for this bizarre situation. Relying on a new definition of "information", which can be derived from Kolmogorov's compexity theory and Chaitin's notion of algorithmic inf...

  4. Virtual brain mapping: Meta-analysis and visualization in functional neuroimaging

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup

    automatically model and visualize several studies at once. We model a set of 3-dimensional coordinates by a voxelization step where flexible probability density models such as kernel density estimators produce a voxel-volume representation of a study, allowing us to represent all coordinate data in one single......Map database we found errors, e.g., stemming from confusion of centimeters and millimeters during entering and errors in the original article. Conditional probability density modeling also enables generation of probabilistic atlases and automatic probabilistic anatomical labeling of new coordinates...... lists. Image-based indices can be created by singular value decomposition and by matching individual volumes against eigenimages. Individual experiments, sets of experiments as well as results from meta-analyses can be rendered as glyphs, cut-planes or isosurfaces in 3-dimensional Corner Cube...

  5. Raoultella ornithinolytica: An unusual pathogen for prosthetic joint infection.

    Science.gov (United States)

    Seng, Piseth; Theron, Françoise; Honnorat, Estelle; Prost, Didier; Fournier, Pierre-Edouard; Stein, Andreas

    2016-01-01

    We herein report the first case of a prosthetic joint infection caused by Raoultella ornithinolytica in an immunocompetent patient. The clinical outcome was favorable after a two-stage prosthetic exchange and a six-month course of antimicrobial therapy.

  6. The Prosthetic Experience Between Body and Technology

    DEFF Research Database (Denmark)

    Søndergaard, Morten

    2016-01-01

    In this paper, I argue that a prosthetic aesthetic instigated by experimental art practices operate with and within a ‘second nature’ – in-between science and art. Drawing on theories from Dewey and Edelman and examples from Da Vinci, Brancusi, Man Ray, Dali and Stelarc, I am calling for an exper......In this paper, I argue that a prosthetic aesthetic instigated by experimental art practices operate with and within a ‘second nature’ – in-between science and art. Drawing on theories from Dewey and Edelman and examples from Da Vinci, Brancusi, Man Ray, Dali and Stelarc, I am calling...... for an experience-based analysis of experimental practices operating between body and technology. These practices, which, rather than falling into the category of science fiction or horror cinema as some recent critique from post-human studies would have it, are pointing towards a genealogy of prosthetic experience...

  7. Optimising the prescription of prosthetic technologies (opptec): Outcome measures for evidence based prosthetic practice and use

    LENUS (Irish Health Repository)

    Ryall, Dr Nicola

    2010-01-01

    This study provided a forum for patients and service providers to voice their opinions in what they believe to be the important predictors and outcomes involved in successful rehabilitation following limb loss. To develop a consensus on the most important outcomes and factors to address for both the lower limb and upper limb prosthetic prescription process, the above data relating to lower limb and upper prosthetics were subsequently used in the next phase of the research involving two Delphi surveys of 23 and 53 experts within the lower limb and upper limb amputation and prosthetic field respectively, including users, service providers and researchers.\\r\

  8. Mesofluidic controlled robotic or prosthetic finger

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Randall F; Jansen, John F; Love, Lonnie J

    2013-11-19

    A mesofluidic powered robotic and/or prosthetic finger joint includes a first finger section having at least one mesofluidic actuator in fluid communication with a first actuator, a second mesofluidic actuator in fluid communication with a second actuator and a second prosthetic finger section pivotally connected to the first finger section by a joint pivot, wherein the first actuator pivotally cooperates with the second finger to provide a first mechanical advantage relative to the joint point and wherein the second actuator pivotally cooperates with the second finger section to provide a second mechanical advantage relative to the joint point.

  9. Brain potentials reflect access to visual and emotional memories for faces.

    Science.gov (United States)

    Bobes, Maria A; Quiñonez, Ileana; Perez, Jhoanna; Leon, Inmaculada; Valdés-Sosa, Mitchell

    2007-05-01

    Familiar faces convey different types of information, unlocking memories related to social-emotional significance. Here, the availability over time of different types of memory was evaluated using the time-course of P3 event related potentials. Two oddball paradigms were employed, both using unfamiliar faces as standards. The infrequent targets were, respectively, artificially-learned faces (devoid of social-emotional content) and faces of acquaintances. Although in both tasks targets were detected accurately, the corresponding time-course and scalp distribution of the P3 responses differed. Artificially-learned and acquaintance faces both elicited a P3b, maximal over centro-parietal sites, and a latency of 500ms. Faces of acquaintances elicited an additional component, an early P3 maximal over frontal sites: with a latency of 350ms. This suggests that visual familiarity can only trigger the overt recognition processes leading to the slower P3b, whereas emotional-social information can also elicit fast and automatic assessments (indexed by the frontal-P3) crucial for successful social interactions.

  10. Functional clustering drives encoding improvement in a developing brain network during awake visual learning.

    Directory of Open Access Journals (Sweden)

    Kaspar Podgorski

    2012-01-01

    Full Text Available Sensory experience drives dramatic structural and functional plasticity in developing neurons. However, for single-neuron plasticity to optimally improve whole-network encoding of sensory information, changes must be coordinated between neurons to ensure a full range of stimuli is efficiently represented. Using two-photon calcium imaging to monitor evoked activity in over 100 neurons simultaneously, we investigate network-level changes in the developing Xenopus laevis tectum during visual training with motion stimuli. Training causes stimulus-specific changes in neuronal responses and interactions, resulting in improved population encoding. This plasticity is spatially structured, increasing tuning curve similarity and interactions among nearby neurons, and decreasing interactions among distant neurons. Training does not improve encoding by single clusters of similarly responding neurons, but improves encoding across clusters, indicating coordinated plasticity across the network. NMDA receptor blockade prevents coordinated plasticity, reduces clustering, and abolishes whole-network encoding improvement. We conclude that NMDA receptors support experience-dependent network self-organization, allowing efficient population coding of a diverse range of stimuli.

  11. High-frequency combination coding-based steady-state visual evoked potential for brain computer interface

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Feng; Zhang, Xin; Xie, Jun; Li, Yeping; Han, Chengcheng; Lili, Li; Wang, Jing [School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Xu, Guang-Hua [School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710054 (China)

    2015-03-10

    This study presents a new steady-state visual evoked potential (SSVEP) paradigm for brain computer interface (BCI) systems. The goal of this study is to increase the number of targets using fewer stimulation high frequencies, with diminishing subject’s fatigue and reducing the risk of photosensitive epileptic seizures. The new paradigm is High-Frequency Combination Coding-Based High-Frequency Steady-State Visual Evoked Potential (HFCC-SSVEP).Firstly, we studied SSVEP high frequency(beyond 25 Hz)response of SSVEP, whose paradigm is presented on the LED. The SNR (Signal to Noise Ratio) of high frequency(beyond 40 Hz) response is very low, which is been unable to be distinguished through the traditional analysis method; Secondly we investigated the HFCC-SSVEP response (beyond 25 Hz) for 3 frequencies (25Hz, 33.33Hz, and 40Hz), HFCC-SSVEP produces n{sup n} with n high stimulation frequencies through Frequence Combination Code. Further, Animproved Hilbert-huang transform (IHHT)-based variable frequency EEG feature extraction method and a local spectrum extreme target identification algorithmare adopted to extract time-frequency feature of the proposed HFCC-SSVEP response.Linear predictions and fixed sifting (iterating) 10 time is used to overcome the shortage of end effect and stopping criterion,generalized zero-crossing (GZC) is used to compute the instantaneous frequency of the proposed SSVEP respondent signals, the improved HHT-based feature extraction method for the proposed SSVEP paradigm in this study increases recognition efficiency, so as to improve ITR and to increase the stability of the BCI system. what is more, SSVEPs evoked by high-frequency stimuli (beyond 25Hz) minimally diminish subject’s fatigue and prevent safety hazards linked to photo-induced epileptic seizures, So as to ensure the system efficiency and undamaging.This study tests three subjects in order to verify the feasibility of the proposed method.

  12. Comparative roll-over analysis of prosthetic feet

    NARCIS (Netherlands)

    Curtze, Carolin; Hof, At L.; van Keeken, Helco G.; Halbertsma, Jan P. K.; Postema, Klaas; Otten, Bert

    2009-01-01

    A prosthetic foot is a key element of a prosthetic leg, literally forming the basis for a stable and efficient amputee gait. We determined the roll-over characteristics of a broad range of prosthetic feet and examined the effect of a variety of shoes on these characteristics. The body weight of a pe

  13. Visualization of the functional recovery process of brain and spinal cord after injury

    International Nuclear Information System (INIS)

    Elucidation of the process of spontaneous functional recovery of central nervous system (CNS) after injury like trauma and stroke is important to develop and conduct the better rehabilitation training to promote the recuperation. Authors have developed a macaque monkey model with an artificial injury of cervical corticospinal tract (CST), where its elaborative motor activity of fingers spontaneously recovers. This paper describes the selective CST injury procedure, its recovery process in finger movement and in CNS images by positron emission tomography (PET), and validation of the obtained images by nerve block. For the injury, CST is cut selectively at monkey's C4/C5 boundary to block the hand motion nerve and to preserve the 2-synapse pathway through the propriospinal neuron, which results in acute loss of grasping a piece of potato food. At 1-3 months after the treatment, the elaborative motor activity of fingers completely recovers. During this recovery period, PET is conducted to trace the brain blood flow change at the upper center of the motion in realizing/grasping food, where the dorsal pathway and cerebellar nuclei are activated at the motion in the untreated animal. At 1-2 months after operation, the blood flow is found increased in the two areas above and the increased area, widened relative to those before operation. At 3 months (at complete functional recovery), the activity in the ipsilateral primary motor area returns to normal level and in the contralateral area, is spread accompanying the increase in the bilateral dorsal premotor and secondary somatosensory areas. Imaging results are validated by nerve block with micro-injection of muscimol into the activated areas during the task motor. Findings are helpful for developing a method to promote the compensation of nervous function after injury. (K.T.)

  14. Towards an optimization of stimulus parameters for brain-computer interfaces based on steady state visual evoked potentials.

    Directory of Open Access Journals (Sweden)

    Anna Duszyk

    Full Text Available Efforts to construct an effective brain-computer interface (BCI system based on Steady State Visual Evoked Potentials (SSVEP commonly focus on sophisticated mathematical methods for data analysis. The role of different stimulus features in evoking strong SSVEP is less often considered and the knowledge on the optimal stimulus properties is still fragmentary. The goal of this study was to provide insight into the influence of stimulus characteristics on the magnitude of SSVEP response. Five stimuli parameters were tested: size, distance, colour, shape, and presence of a fixation point in the middle of each flickering field. The stimuli were presented on four squares on LCD screen, with each square highlighted by LEDs flickering with different frequencies. Brighter colours and larger dimensions of flickering fields resulted in a significantly stronger SSVEP response. The distance between stimulation fields and the presence or absence of the fixation point had no significant effect on the response. Contrary to a popular belief, these results suggest that absence of the fixation point does not reduce the magnitude of SSVEP response. However, some parameters of the stimuli such as colour and the size of the flickering field play an important role in evoking SSVEP response, which indicates that stimuli rendering is an important factor in building effective SSVEP based BCI systems.

  15. A Data Mining Approach for Visual and Analytical Identification of Neurorehabilitation Ranges in Traumatic Brain Injury Cognitive Rehabilitation

    Directory of Open Access Journals (Sweden)

    Alejandro García-Rudolph

    2015-01-01

    Full Text Available Traumatic brain injury (TBI is a critical public health and socioeconomic problem throughout the world. Cognitive rehabilitation (CR has become the treatment of choice for cognitive impairments after TBI. It consists of hierarchically organized tasks that require repetitive use of impaired cognitive functions. One important focus for CR professionals is the number of repetitions and the type of task performed throughout treatment leading to functional recovery. However, very little research is available that quantifies the amount and type of practice. The Neurorehabilitation Range (NRR and the Sectorized and Annotated Plane (SAP have been introduced as a means of identifying formal operational models in order to provide therapists with decision support information for assigning the most appropriate CR plan. In this paper we present a novel methodology based on combining SAP and NRR to solve what we call the Neurorehabilitation Range Maximal Regions (NRRMR problem and to generate analytical and visual tools enabling the automatic identification of NRR. A new SAP representation is introduced and applied to overcome the drawbacks identified with existing methods. The results obtained show patterns of response to treatment that might lead to reconsideration of some of the current clinical hypotheses.

  16. Analogue mouse pointer control via an online steady state visual evoked potential (SSVEP) brain-computer interface

    Science.gov (United States)

    Wilson, John J.; Palaniappan, Ramaswamy

    2011-04-01

    The steady state visual evoked protocol has recently become a popular paradigm in brain-computer interface (BCI) applications. Typically (regardless of function) these applications offer the user a binary selection of targets that perform correspondingly discrete actions. Such discrete control systems are appropriate for applications that are inherently isolated in nature, such as selecting numbers from a keypad to be dialled or letters from an alphabet to be spelled. However motivation exists for users to employ proportional control methods in intrinsically analogue tasks such as the movement of a mouse pointer. This paper introduces an online BCI in which control of a mouse pointer is directly proportional to a user's intent. Performance is measured over a series of pointer movement tasks and compared to the traditional discrete output approach. Analogue control allowed subjects to move the pointer faster to the cued target location compared to discrete output but suffers more undesired movements overall. Best performance is achieved when combining the threshold to movement of traditional discrete techniques with the range of movement offered by proportional control.

  17. Ictal and interictal 99mTc-HMPAO brain SPECT of a MELAS case presented with epilepsy-like visual hallucination.

    Science.gov (United States)

    Wei, Cheng-Yu; Hsiao, Heng-Long; Chen, Shang-Chi; Hung, Guang-Uei; Kao, Chia-Hung

    2012-09-01

    A 55-year-old woman was diagnosed with the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). She was referred for Tc-HMPAO brain SPECT because of visual hallucinations, which were suspected to be related to epileptic seizures. Ictal SPECT images showed remarkable hyperperfusion in the left occipital cortex, which returned to near-normal status on the interictal SPECT images after treatment with anticonvulsants. It is very rare to see such an ictal SPECT image of epileptic or epilepsy-like disorders, especially in the setting of MELAS syndrome with visual hallucination.

  18. Multimodality Imaging Assessment of Prosthetic Heart Valves

    NARCIS (Netherlands)

    Suchá, D.; Symersky, Petr; Tanis, W; Mali, Willem P Th M; Leiner, Tim; van Herwerden, LA; Budde, Ricardo P J

    2015-01-01

    Echocardiography and fluoroscopy are the main techniques for prosthetic heart valve (PHV) evaluation, but because of specific limitations they may not identify the morphological substrate or the extent of PHV pathology. Cardiac computed tomography (CT) and magnetic resonance imaging (MRI) have emerg

  19. Consumer satisfaction in prosthetics and orthotics facilities

    NARCIS (Netherlands)

    Geertzen, J.H.B.; Gankema, H.G.J.; Groothoff, J.W.; Dijkstra, P.U.

    2002-01-01

    The aim of this study was to assess consumer/patient satisfaction with the services of the prosthetics and orthotics (P&O) facilities in the north of the Netherlands, using a modified SERVQUAL questionnaire. In this questionnaire, consumer interests and experiences are assessed on a 5-point Likert s

  20. Induced arousal following zolpidem treatment in a vegetative state after brain injury in 7 cases Analysis using visual single photon emission computerized tomography and digitized cerebral state monitor

    Institute of Scientific and Technical Information of China (English)

    Bo Du; Aijun Shan; Di Yang; Wei Xiang

    2008-01-01

    BACKGROUND: Several studies have reported the use of zolpidem for induced arousal after permanent vegetative states. However, changes in brain function and EMG after zolpidem treatment requires further investigation. OBJECTIVE: To investigate the effect of zolpidem, an unconventional drug, on inducing arousal in patients in a permanent vegetative state after brain injury using visual single photon emission computerized tomography and digitized cerebral state monitor. DESIGN: A self-controlled observation. SETTING: Shenzhen People's Hospital.PARTICIPANTS: Seven patients in a permanent vegetative state were selected from the Department of Neurosurgery, Shenzhen People's Hospital from March 2005 to May 2007. The group included 5 males and 2 females, 24–55 years of age, with a mean age of 38.5 years. All seven patients had been in a permanent vegetative statement for at least six months. The patient group included three comatose patients, who had sustained injuries to the cerebral cortex, basal ganglia, or thalamus in motor vehicle accidents, and four patients, who had suffered primary/secondary brain stem injury. Informed consents were obtained from the patients’ relatives. METHODS: The patients brains were imaged by 99Tcm ECD single photon emission computerized tomography prior to treatment with zolpidem [Sanofi Winthrop Industrie, France, code number approved by the State Food & Drug Administration (SFDA) J20040033, specification 10 mg per tablet. At 8:00 p.m., 10 mg zolpidem was dissolved with distilled water and administered through a nasogastric tube at 1 hour before and after treatment and 1 week following treatment, respectively. Visual analysis of cerebral perfusion changes in the injured brain regions before and after treatment was performed. Simultaneously, three monitoring parameters were obtained though a cerebral state monitor, which included cerebral state index, electromyographic index, and burst suppression index. MAIN OUTCOME MEASURES: Comparison

  1. Brain SPECT in mesial temporal lobe epilepsy: comparison between visual analysis and SPM SPECT cerebral na epilepsia de lobo temporal mesial: comparação entre análise visual e SPM

    Directory of Open Access Journals (Sweden)

    Bárbara Juarez Amorim

    2010-04-01

    Full Text Available OBJECTIVE: To compare the accuracy of SPM and visual analysis of brain SPECT in patients with mesial temporal lobe epilepsy (MTLE. METHOD: Interictal and ictal SPECTs of 22 patients with MTLE were performed. Visual analysis were performed in interictal (VISUAL(inter and ictal (VISUAL(ictal/inter studies. SPM analysis consisted of comparing interictal (SPM(inter and ictal SPECTs (SPM(ictal of each patient to control group and by comparing perfusion of temporal lobes in ictal and interictal studies among themselves (SPM(ictal/inter. RESULTS: For detection of the epileptogenic focus, the sensitivities were as follows: VISUAL(inter=68%; VISUAL(ictal/inter=100%; SPM(inter=45%; SPM(ictal=64% and SPM(ictal/inter=77%. SPM was able to detect more areas of hyperperfusion and hypoperfusion. CONCLUSION: SPM did not improve the sensitivity to detect epileptogenic focus. However, SPM detected different regions of hypoperfusion and hyperperfusion and is therefore a helpful tool for better understand pathophysiology of seizures in MTLE.OBJETIVO: Comparar a acurácia do SPM com a análise visual na detecção do foco epileptogênico e alterações perfusionais à distância no SPECT cerebral. MÉTODO: Foram realizados os SPECTs ictal e interictal de 22 pacientes com epilepsia de lobo temporal mesial (ELTM. A análise visual foi realizada nos estudos interictal (VISUAL(inter e ictal (VISUAL(ictal/inter. Na análise com SPM foi comparado o estudo interictal (SPM(inter e ictal (SPM(ictal de cada paciente com o grupo controle e comparou-se a perfusão dos lobos temporais entre os estudos ictal e interictal (SPM(ictal/inter. RESULTADOS: Para a detecção do foco epileptogênico, as sensibilidades foram as seguintes: VISUAL(inter=68%; VISUAL(ictal/inter=100%; SPM(inter=45%; SPM(ictal=64% and SPM(ictal/inter=77%. O SPM foi capaz de detectar mais áreas de hiperperfusão e hipoperfusão. CONCLUSÃO: O SPM não aumentou a sensibilidade na detecção do foco epileptog

  2. Double function of noninvasive intracranial pressure monitoring based on flash visual evoked potentials in unconscious patients with traumatic brain injury.

    Science.gov (United States)

    Wang, Tingzhong; Ma, Shuang; Guan, Yongchang; Du, Jinghua; Liu, Guojun; Zhao, Xianlin

    2016-05-01

    Intracranial pressure (ICP) monitoring based on flash visual evoked potentials (F-VEP) is a noninvasive method of monitoring ICP. The early diagnosis of traumatic optic neuropathy (TON) in unconscious patients with traumatic brain injury (TBI) is a challenge. The aim of this study was to evaluate the function of F-VEP ICP monitoring in predicting TON and detecting contusion enlargement (CE) in unconscious TBI patients using a modified approach. A series of F-VEP ICP-monitored unconscious TBI patients were included in the study. The interocular differences in N2 wave latency (DL) and amplitude (DA) were obtained through monocular flash stimulation. The increases in ICP (dxP) and interchannel difference (dxDC) across various time points were obtained through binocular flash stimulation. The predictive power of DL and DA on TON, as well as of dxP and dxDC on CE, was assessed by logistic regression and receiver operating characteristic (ROC) curve analysis. Patients with TON had a longer DL and a higher DA than those without TON. The dxP and dxDC of patients with CE were both higher than those of patients without CE. The differences were statistically significant. The logistic regression showed that both DL and DA were predictors of TON, whereas only dxDC was a predictor of CE. However, the ROC curve analysis showed that DL had greater predictive power for TON, and dxDC had greater predictive power for CE. An F-VEP ICP monitoring system with a modified approach is beneficial for early diagnosis of TON and prediction of CE in unconscious TBI patients. PMID:26922509

  3. Association between striatal dopamine D2/D3 receptors and brain activation during visual attention: effects of sleep deprivation

    Science.gov (United States)

    Tomasi, D; Wang, G-J; Volkow, N D

    2016-01-01

    Sleep deprivation (SD) disrupts dopamine (DA) signaling and impairs attention. However, the interpretation of these concomitant effects requires a better understanding of dopamine's role in attention processing. Here we test the hypotheses that D2/D3 receptors (D2/D3R) in dorsal and ventral striatum would distinctly regulate the activation of attention regions and that, by decreasing D2/D3, SD would disrupt these associations. We measured striatal D2/D3R using positron emission tomography with [11C]raclopride and brain activation to a visual attention (VA) task using 4-Tesla functional magnetic resonance imaging. Fourteen healthy men were studied during rested wakefulness and also during SD. Increased D2/D3R in striatum (caudate, putamen and ventral striatum) were linearly associated with higher thalamic activation. Subjects with higher D2/D3R in caudate relative to ventral striatum had higher activation in superior parietal cortex and ventral precuneus, and those with higher D2/D3R in putamen relative to ventral striatum had higher activation in anterior cingulate. SD impaired the association between striatal D2/D3R and VA-induced thalamic activation, which is essential for alertness. Findings suggest a robust DAergic modulation of cortical activation during the VA task, such that D2/D3R in dorsal striatum counterbalanced the stimulatory influence of D2/D3R in ventral striatum, which was not significantly disrupted by SD. In contrast, SD disrupted thalamic activation, which did not show counterbalanced DAergic modulation but a positive association with D2/D3R in both dorsal and ventral striatum. The counterbalanced dorsal versus ventral striatal DAergic modulation of VA activation mirrors similar findings during sensorimotor processing (Tomasi et al., 2015) suggesting a bidirectional influence in signaling between the dorsal caudate and putamen and the ventral striatum. PMID:27219347

  4. Development and Use of Visual Explanations: Harnessing the Power of the "Seeing" Brain to Enhance Student Learning

    Science.gov (United States)

    Schmidt, Shelly J.

    2009-01-01

    When students come to class, they bring with them the most powerful processor known to man--the human brain! Our job as teachers is to discover and implement practices that will make the most effective use of those brains. The human brain is a very powerful processor of sensory information, especially with regard to the sense of vision. We can…

  5. Simulated Prosthetic Vision: The Benefits of Computer-Based Object Recognition and Localization.

    Science.gov (United States)

    Macé, Marc J-M; Guivarch, Valérian; Denis, Grégoire; Jouffrais, Christophe

    2015-07-01

    Clinical trials with blind patients implanted with a visual neuroprosthesis showed that even the simplest tasks were difficult to perform with the limited vision restored with current implants. Simulated prosthetic vision (SPV) is a powerful tool to investigate the putative functions of the upcoming generations of visual neuroprostheses. Recent studies based on SPV showed that several generations of implants will be required before usable vision is restored. However, none of these studies relied on advanced image processing. High-level image processing could significantly reduce the amount of information required to perform visual tasks and help restore visuomotor behaviors, even with current low-resolution implants. In this study, we simulated a prosthetic vision device based on object localization in the scene. We evaluated the usability of this device for object recognition, localization, and reaching. We showed that a very low number of electrodes (e.g., nine) are sufficient to restore visually guided reaching movements with fair timing (10 s) and high accuracy. In addition, performance, both in terms of accuracy and speed, was comparable with 9 and 100 electrodes. Extraction of high level information (object recognition and localization) from video images could drastically enhance the usability of current visual neuroprosthesis. We suggest that this method-that is, localization of targets of interest in the scene-may restore various visuomotor behaviors. This method could prove functional on current low-resolution implants. The main limitation resides in the reliability of the vision algorithms, which are improving rapidly.

  6. Preliminary MRI study on hemodynamics after prosthetic cardiac valve implantation

    International Nuclear Information System (INIS)

    Objective: To assess the function of prosthetic valve by magnetic resonance imaging (MRI), and to measure the blood velocity downstream of prosthetic valve and three-dimensional surface profiles so as to provide the original materials for appearance and development of thrombi-embolic complications in the long time follow-up. Methods: Twenty-seven cases with prosthetic aortic valve were examined and the blood velocity was measured by using MRI. The diseased heart valves were replaced with two prosthetic valves in 20 cases, and replaced with single prosthetic valve in 7 cases. The axial velocity components were measured at three positions near the valve including half, one, and two diameter downstream in the ascending aorta. Two and three-dimensional surface profile reconstruction were analyzed by using flow analysis software and Matlab 6.5 software. Results: In 16 cases with prosthetic aortic valve replacement with two leaflets prosthetic valves, the velocity profiles downstream of the valve prosthetic reflecting the valve design was nearly three velocity, jets of the two major orifices and the central slit between the two leaflets. In 4 cases with prosthetic aortic valve replace with Sorin two leaflets prosthetic valve, the velocity profiles downstream was nearly two velocity jets of the two major orifices. In 20 cases replaced with two leaflets prosthetic valves, blood velocity profiles were skewed with highest velocities. Seven cases with single leaflet showed single velocity jets of the major orifices at peak systole. Retrograde velocities occurred in part of the lateral orifice regions in 26 cases. Three-dimensional surface profiles downstream of the prosthetic aortic valve reflected the valve design. The blood velocity profiles with prosthetic aortic valve in the one diameter downstream in the ascending aorta clearly showed the valve design. Conclusion: MRI is a non-invasive, direct, and in-vivo method of choice to assess the valvular function and is the

  7. Common Prosthetic Implant Complications in Fixed Restorations.

    Science.gov (United States)

    Link-Bindo, Elyce E; Soltys, James; Donatelli, David; Cavanaugh, Richard

    2016-07-01

    Many clinicians consider implants to be one of the most important innovations in dental care. Even so, over the past 40 years of implant dentistry, complications have been a constant struggle for restorative dentists, surgeons, and patients alike. Implant-related problems can be particularly challenging and frustrating, especially given that an implant is thought to be a "lifetime" solution expected to yield minimal difficulties. This, however, is not necessarily the case with prosthetic restorations. With innovations in implant technology continuing to rapidly advance, maintaining knowledge of all the latest developments can be challenging for clinicians. The purpose of this article is to provide a basic understanding of the treatment, management, and prevention of common prosthetic and technical implant complications seen in the office of a restorative dentist. PMID:27548395

  8. Prosthetic management of an ocular defect

    Directory of Open Access Journals (Sweden)

    Siddesh Kumar Chintal

    2010-01-01

    Full Text Available The disfigurement associated with the loss of an eye can cause significant physical and emotional problems. Various treatment modalities are available, one of which is implants. Although implant has a superior outcome, it may not be advisable in all patients due to economic factors. The present article describes the prosthetic management of an ocular defect with a custom-made ocular prosthesis.

  9. New developments in prosthetic arm systems

    Directory of Open Access Journals (Sweden)

    Vujaklija I

    2016-07-01

    Full Text Available Ivan Vujaklija,1 Dario Farina,1 Oskar C Aszmann2 1Institute of Neurorehabilitation Systems, Bernstein Focus Neurotechnology Göttingen, University Medical Center Göttingen, Georg-August University, Göttingen, Germany; 2Christian Doppler Laboratory for Restoration of Extremity Function, Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria Abstract: Absence of an upper limb leads to severe impairments in everyday life, which can further influence the social and mental state. For these reasons, early developments in cosmetic and body-driven prostheses date some centuries ago, and they have been evolving ever since. Following the end of the Second World War, rapid developments in technology resulted in powered myoelectric hand prosthetics. In the years to come, these devices were common on the market, though they still suffered high user abandonment rates. The reasons for rejection were trifold – insufficient functionality of the hardware, fragile design, and cumbersome control. In the last decade, both academia and industry have reached major improvements concerning technical features of upper limb prosthetics and methods for their interfacing and control. Advanced robotic hands are offered by several vendors and research groups, with a variety of active and passive wrist options that can be articulated across several degrees of freedom. Nowadays, elbow joint designs include active solutions with different weight and power options. Control features are getting progressively more sophisticated, offering options for multiple sensor integration and multi-joint articulation. Latest developments in socket designs are capable of facilitating implantable and multiple surface electromyography sensors in both traditional and osseointegration-based systems. Novel surgical techniques in combination with modern, sophisticated hardware are enabling restoration of dexterous upper limb

  10. Rapid prototyping technologies in prosthetic dentistry

    OpenAIRE

    YILDIRIM, Arş. Gör. Dt. Melike Pınar; BAYINDIR, Prof. Dr. Funda

    2013-01-01

    Emerged as the concept of rapid prototyping technology, nowadays, is seen as the future of quick and direct production. This technology found applications with metal framework of fixed partial dentures, framework of removable partial dentures, facial protheses and titanium implants in prosthetic dentistry. The virtual image of the restoration is tranferred to the computer and the laser beam is sintered the selected areas on the alloy powders and the restoration is produced layer by layer at s...

  11. [Optogenetics and prosthetic treatment of retinal degeneration].

    Science.gov (United States)

    Kirpichnikov, M P; Ostrovskiy, M A

    2015-01-01

    This is a review of the current state of optogenetics-based research in the field of ophthalmology and physiology of vision. Optogenetics employs an interdisciplinary approach that amalgamates gene engineering, optics, and physiology. It involves exogenous expression of a light-activated protein in a very particular retinal cell enabling regulation (stimulation vs. inhibition) of its physiological activity. The experience with gene therapy came in very useful for optogenetics. However, unlike gene therapy, which is aimed at repairing damaged genes or replacing them with healthy ones, optogenetics is focused on protein genes delivery for further molecular control of the cell. In retina, the loss of photoreceptors is not necessarily followed by neuronal loss (at least ganglion cells remain intact), which determines the practicability of prosthetic treatment. Clinical trials can now be considered, owing to the first successful conversion of ganglion cells of mouse degenerative retinas into artificial photoreceptive cells with ON and OFF receptive fields, which is crucial for spatial vision. The following issues are reviewed here in detail: 1. Choice of cell targets within the degenerative retina. 2. Strategy of utilizing the existing light-sensitive agents and development of new optogenetic tools. 3. Gene delivery and expression in retinal cells. 4. Methods of evaluating the treatment success. 5. Selection criteria for optogenetic prosthetics. The conclusion discusses currently unsolved problems and prospects for optogenetic approaches to retinal prosthetics.

  12. Does Seeing Ice Really Feel Cold? Visual-Thermal Interaction under an Illusory Body-Ownership

    OpenAIRE

    Shoko Kanaya; Yuka Matsushima; Kazuhiko Yokosawa

    2012-01-01

    Although visual information seems to affect thermal perception (e.g. red color is associated with heat), previous studies have failed to demonstrate the interaction between visual and thermal senses. However, it has been reported that humans feel an illusory thermal sensation in conjunction with an apparently-thermal visual stimulus placed on a prosthetic hand in the rubber hand illusion (RHI) wherein an individual feels that a prosthetic (rubber) hand belongs to him/her. This study tests the...

  13. Below knee prosthetic socket designs and suspension systems.

    Science.gov (United States)

    Edwards, M L

    2000-08-01

    The prosthetic socket must act as a customized connection between the residual limb's surrounding tissues and the prosthetic components. The socket must be designed to control weight bearing, suspension, and ambulation stability. When making a below-the-knee socket, the prosthetist attempts to maximize loading and minimize displacements, such as vertical, transverse, or rotational. This article discusses the engineering designs or shapes of the two basic forms of below-the-knee prosthetic sockets used today.

  14. Neuroengineering tools/applications for bidirectional interfaces, brain computer interfaces, and neuroprosthetic implants - a review of recent progress

    Directory of Open Access Journals (Sweden)

    Ryan M Rothschild

    2010-10-01

    Full Text Available The main focus of this review is to provide a holistic amalgamated overview of the most recent human in vivo techniques for implementing brain-computer interfaces (BCIs, bidirectional interfaces and neuroprosthetics. Neuroengineering is providing new methods for tackling current difficulties; however neuroprosthetics have been studied for decades. Recent progresses are permitting the design of better systems with higher accuracies, repeatability and system robustness. Bidirectional interfaces integrate recording and the relaying of information from and to the brain for the development of BCIs. The concepts of non-invasive and invasive recording of brain activity are introduced. This includes classical and innovative techniques like electroencephalography (EEG and near-infrared spectroscopy (NIRS. Then the problem of gliosis and solutions for (semi- permanent implant biocompatibility such as innovative implant coatings, materials and shapes are discussed. Implant power and the transmission of their data through implanted pulse generators (IPGs and wireless telemetry are taken into account. How sensation can be relayed back to the brain to increase integration of the neuroengineered systems with the body by methods such as micro-stimulation and transcranial magnetic stimulation (TMS are then addressed. The neuroprosthetic section discusses some of the various types and how they operate. Visual prosthetics are discussed and the three types, dependant on implant location, are examined. Auditory prosthetics, being cochlear or cortical, are then addressed. Replacement hand and limb prosthetics are then considered. These are followed by sections concentrating on the control of wheelchairs, computers and robotics directly from brain activity as recorded by non-invasive and invasive techniques.

  15. Analysis of brain-stem auditory evoked potential and visual evoked potential in patients with Parkinson disease

    Institute of Scientific and Technical Information of China (English)

    Qiaorong Deng; Jianzhong Deng; Yanmin Zhao; Xiaohai Yan; Pin Chen

    2006-01-01

    BACKGROUND: With the development of neuroelectrophysiology, it had been identified that all kinds of evoked potentials might reflect the functional status of corresponding pathway. Evoked potentials recruited in the re search of PD, it can be known whether other functional pathway of nervous system is impaired. OBJECTIVE: To observe whether brainstem auditory and visual passageway are impaired in patients with Parkinson disease (PD), and compare with non-PD patients concurrently. DESIGN: A non-randomized concurrent controlled observation. SETTINGS: Henan Provincial Tumor Hospital; Anyang District Hospital. PARTICIPANTS: Thirty-two cases of PD outpatients and inpatients, who registered in the Department of Neurology, Anyang District Hospital from October 1997 to February 2006, were enrolled as the PD group, including 20 males and 12 females, aged 50-72 years old. Inclusive criteria: In accordance with the diagnostic criteria of PD recommended by the dyskinesia and PD group of neurology branch of Chinese Medical Association. Patients with diseases that could cause Parkinson syndrome were excluded by CT scanning or MRI examination. Meanwhile, 30 cases with non-neurological disease were selected from the Department of Internal Medicine of our hospital as the control group, including 19 males and 11 females, aged 45-70 years old. Including criteria: Without history of neurological disease or psychiatric disease; showing normal image on CT. And PD, Parkinson syndrome and Parkinsonism-plus were excluded by professional neurologist. All the patients were informed and agreed with the examination and clinical observation. METHODS: The electrophysiological examination and clinical observation of the PD patients and controls were conducted. The Reporter type 4-channel evoked potential machine (Italy) was used to check brain-stem auditory evoked potential (BAEP) and visual evoked potential (VEP). Why to be examined was explained to test taker. BAEP recording electrode was plac

  16. The role of osteoblasts in peri-prosthetic osteolysis.

    LENUS (Irish Health Repository)

    O'Neill, S C

    2013-08-01

    Peri-prosthetic osteolysis and subsequent aseptic loosening is the most common reason for revising total hip replacements. Wear particles originating from the prosthetic components interact with multiple cell types in the peri-prosthetic region resulting in an inflammatory process that ultimately leads to peri-prosthetic bone loss. These cells include macrophages, osteoclasts, osteoblasts and fibroblasts. The majority of research in peri-prosthetic osteolysis has concentrated on the role played by osteoclasts and macrophages. The purpose of this review is to assess the role of the osteoblast in peri-prosthetic osteolysis. In peri-prosthetic osteolysis, wear particles may affect osteoblasts and contribute to the osteolytic process by two mechanisms. First, particles and metallic ions have been shown to inhibit the osteoblast in terms of its ability to secrete mineralised bone matrix, by reducing calcium deposition, alkaline phosphatase activity and its ability to proliferate. Secondly, particles and metallic ions have been shown to stimulate osteoblasts to produce pro inflammatory mediators in vitro. In vivo, these mediators have the potential to attract pro-inflammatory cells to the peri-prosthetic area and stimulate osteoclasts to absorb bone. Further research is needed to fully define the role of the osteoblast in peri-prosthetic osteolysis and to explore its potential role as a therapeutic target in this condition.

  17. An extremely lightweight fingernail worn prosthetic interface device

    Science.gov (United States)

    Yetkin, Oguz; Ahluwalia, Simranjit; Silva, Dinithi; Kasi-Okonye, Isioma; Volker, Rachael; Baptist, Joshua R.; Popa, Dan O.

    2016-05-01

    Upper limb prosthetics are currently operated using several electromyography sensors mounted on an amputee's residual limb. In order for any prosthetic driving interface to be widely adopted, it needs to be responsive, lightweight, and out of the way when not being used. In this paper we discuss the possibility of replacing such electrodes with fingernail optical sensor systems mounted on the sound limb. We present a prototype device that can detect pinch gestures and communicate with the prosthetic system. The device detects the relative position of fingers to each other by measuring light transmitted via tissue. Applications are not limited to prosthetic control, but can be extended to other human-machine interfaces.

  18. Dental prosthetic status and prosthetic need of the institutionalized elderly living in geriatric homes in mangalore: a pilot study.

    Science.gov (United States)

    Shenoy, Rekha P; Hegde, Vijaya

    2011-01-01

    Introduction. To promote oral health among the elderly, we need to know their prosthetic status and prosthetic need. Hence, a survey of prosthetic status and need of elderly inmates of old age homes in Mangalore was done. Materials and Methods. A cross-sectional study was undertaken, and 133 subjects aged 60 years and above were examined (54.9% males and 45.1% females). Results. Eighty-eight percent of those examined were fully edentulous, and only 12% had complete dentures; none of the study subjects had partial dentures. Prosthetic status was significantly associated with gender (P = .024), while prosthetic need and gender were not significantly associated (P = .395). Conclusions. A high unmet need for prosthetic care existed among the institutionalized elderly surveyed.

  19. Facial identification in very low-resolution images simulating prosthetic vision

    Science.gov (United States)

    Chang, M. H.; Kim, H. S.; Shin, J. H.; Park, K. S.

    2012-08-01

    Familiar facial identification is important to blind or visually impaired patients and can be achieved using a retinal prosthesis. Nevertheless, there are limitations in delivering the facial images with a resolution sufficient to distinguish facial features, such as eyes and nose, through multichannel electrode arrays used in current visual prostheses. This study verifies the feasibility of familiar facial identification under low-resolution prosthetic vision and proposes an edge-enhancement method to deliver more visual information that is of higher quality. We first generated a contrast-enhanced image and an edge image by applying the Sobel edge detector and blocked each of them by averaging. Then, we subtracted the blocked edge image from the blocked contrast-enhanced image and produced a pixelized image imitating an array of phosphenes. Before subtraction, every gray value of the edge images was weighted as 50% (mode 2), 75% (mode 3) and 100% (mode 4). In mode 1, the facial image was blocked and pixelized with no further processing. The most successful identification was achieved with mode 3 at every resolution in terms of identification index, which covers both accuracy and correct response time. We also found that the subjects recognized a distinctive face especially more accurately and faster than the other given facial images even under low-resolution prosthetic vision. Every subject could identify familiar faces even in very low-resolution images. And the proposed edge-enhancement method seemed to contribute to intermediate-stage visual prostheses.

  20. The Effect of Mode of Visual Presentation (Motion vs. Still) on the Brain Wave Production of College Students.

    Science.gov (United States)

    Hines, Stephen J.

    The purpose of this study was to measure and analyze viewers' electroencephalographic reactions to motion and still pictures, and to increase knowledge on the differential impact of the two modes on brain wave production. Since beta brain wave indicates focused attention, an additional purpose was to determine whether the two media differed…

  1. Matching spatial with ontological brain regions using Java tools for visualization, database access, and integrated data analysis.

    NARCIS (Netherlands)

    Bezgin, G.; Reid, A.T.; Schubert, D.; Kotter, R.

    2009-01-01

    Brain atlases are widely used in experimental neuroscience as tools for locating and targeting specific brain structures. Delineated structures in a given atlas, however, are often difficult to interpret and to interface with database systems that supply additional information using hierarchically o

  2. Does Silent Reading Speed in Normal Adult Readers Depend on Early Visual Processes? Evidence from Event-Related Brain Potentials

    Science.gov (United States)

    Korinth, Sebastian Peter; Sommer, Werner; Breznitz, Zvia

    2012-01-01

    Little is known about the relationship of reading speed and early visual processes in normal readers. Here we examined the association of the early P1, N170 and late N1 component in visual event-related potentials (ERPs) with silent reading speed and a number of additional cognitive skills in a sample of 52 adult German readers utilizing a Lexical…

  3. Neuro-Prosthetic Implants With Adjustable Electrode Arrays

    Science.gov (United States)

    Whitacre, Jay; DelCastillo, Linda Y.; Mojarradi, Mohammad; Johnson, Travis; West, William; Andersen, Richard

    2006-01-01

    Brushlike arrays of electrodes packaged with application-specific integrated circuits (ASICs) are undergoing development for use as electronic implants especially as neuro-prosthetic devices that might be implanted in brains to detect weak electrical signals generated by neurons. These implants partly resemble the ones reported in Integrated Electrode Arrays for Neuro-Prosthetic Implants (NPO-21198), NASA Tech Briefs, Vol. 27, No. 2 (February 2003), page 48. The basic idea underlying both the present and previously reported implants is that the electrodes would pick up signals from neurons and the ASICs would amplify and otherwise preprocess the signals for monitoring by external equipment. The figure presents a simplified and partly schematic view of an implant according to the present concept. Whereas the electrodes in an implant according to the previously reported concept would be microscopic wires, the electrodes according to the present concept are in the form of microscopic needles. An even more important difference would be that, unlike the previously reported concept, the present concept calls for the inclusion of microelectromechanical actuators for adjusting the depth of penetration of the electrodes into brain tissue. The prototype implant now under construction includes an array of 100 electrodes and corresponding array of electrode contact pads formed on opposite faces of a plate fabricated by techniques that are established in the art of microelectromechanical systems (MEMS). A mixed-signal ASIC under construction at the time of reporting the information for this article will include 100 analog amplifier channels (one amplifier per electrode). On one face of the mixed-signal ASIC there will be a solder-bump/micro-pad array that will have the same pitch as that of the electrode array, and that will be used to make the electrical and mechanical connections between the electrode array and the ASIC. Once the electrode array and the ASIC are soldered

  4. Visual cognition

    Energy Technology Data Exchange (ETDEWEB)

    Pinker, S.

    1985-01-01

    This book consists of essays covering issues in visual cognition presenting experimental techniques from cognitive psychology, methods of modeling cognitive processes on computers from artificial intelligence, and methods of studying brain organization from neuropsychology. Topics considered include: parts of recognition; visual routines; upward direction; mental rotation, and discrimination of left and right turns in maps; individual differences in mental imagery, computational analysis and the neurological basis of mental imagery: componental analysis.

  5. Behavior of parasite-specific effector CD8+ T cells in the brain and visualization of a kinesis-associated system of reticular fibers.

    Science.gov (United States)

    Wilson, Emma H; Harris, Tajie H; Mrass, Paulus; John, Beena; Tait, Elia D; Wu, Gregory F; Pepper, Marion; Wherry, E John; Dzierzinski, Florence; Roos, David; Haydon, Philip G; Laufer, Terri M; Weninger, Wolfgang; Hunter, Christopher A

    2009-02-20

    To understand lymphocyte behavior in the brain, we used two-photon microscopy to visualize effector CD8(+) T cells during toxoplasmic encephalitis. These cells displayed multiple behaviors with two distinct populations of cells apparent: one with a constrained pattern of migration and one with a highly migratory subset. The proportion of these populations varied over time associated with changes in antigen availability as well as T cell expression of the inhibitory receptor PD1. Unexpectedly, the movement of infiltrating cells was closely associated with an infection-induced reticular system of fibers. This observation suggests that, whereas in other tissues pre-existing scaffolds exist that guide lymphocyte migration, in the brain specialized structures are induced by inflammation that guide migration of T cells in this immune-privileged environment.

  6. Prosthesis preference is related to stride-to-stride fluctuations at the prosthetic ankle

    Directory of Open Access Journals (Sweden)

    Shane R. Wurdeman, CP, MSPO

    2013-08-01

    Full Text Available The purpose of this study was to determine the relationship between stride-to-stride fluctuations and prosthesis preference. Thirteen individuals with unilateral, transtibial amputation consented to participate. Individuals walked on a treadmill for 3 min with their prescribed and an alternate prosthesis. Stride-to-stride fluctuations were quantified with the largest Lyapunov exponent (LyE of each joint flexion/extension time series. The change in the LyE was calculated for each major lower-limb joint for both conditions. Participants indicated preference between the prostheses on a continuous visual analog scale. The change in the LyE was correlated with the degree of preference between the two prostheses at the prosthetic ankle. The change in the LyE of the prosthetic ankle was strongly related to the degree of preference (r = 0.629, p = 0.02. Thus, stride-to-stride fluctuations, quantified by the LyE, are strongly related to the patient’s perception of the prosthesis. As a result, the LyE is the first objective measure to detect changes in gait that relate to the patient’s perception of the prosthesis. The LyE should be further examined as a potentially effective prescriptive and outcome measure in prosthetic rehabilitation.

  7. Prosthetic prescription in the Netherlands : an interview with clinical experts

    NARCIS (Netherlands)

    Van Der Linde, H; Geertzen, JHB; Hofstad, CJ; Postema, K

    2004-01-01

    In the process of guideline development for prosthetic prescription in the Netherlands the authors made a study of the daily clinical practice of lower limb prosthetics. Besides the evidence-based knowledge from literature the more implicit knowledge from clinical experts is of importance for guidel

  8. Principles of obstacle avoidance with a transfemoral prosthetic limb

    NARCIS (Netherlands)

    van Keeken, Helco G.; Vrieling, Aline H.; Hof, At L.; Postema, Klaas; Otten, Bert

    2012-01-01

    In this study, conditions that enable a prosthetic knee flexion strategy in transfemoral amputee subjects during obstacle avoidance were investigated. This study explored the hip torque principle and the static ground principle as object avoidance strategies. A prosthetic limb simulator device was u

  9. 21 CFR 870.3935 - Prosthetic heart valve holder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve holder. 870.3935 Section 870.3935 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold...

  10. Stiffness and hysteresis properties of some prosthetic feet

    NARCIS (Netherlands)

    Jaarsveld, van H.W.L.; Grootenboer, H.J.; Vries, de J.; Koopman, H.F.J.M.

    1990-01-01

    A prosthetic foot is an important element of a prosthesis, although it is not always fully recognized that the properties of the foot, along with the prosthetic knee joint and the socket, are in part responsible for the stability and metabolic energy cost during walking. The stiffness and the hyst

  11. Raoultella ornithinolytica: An unusual pathogen for prosthetic joint infection

    Directory of Open Access Journals (Sweden)

    Piseth Seng

    2016-01-01

    Full Text Available We herein report the first case of a prosthetic joint infection caused by Raoultella ornithinolytica in an immunocompetent patient. The clinical outcome was favorable after a two-stage prosthetic exchange and a six-month course of antimicrobial therapy.

  12. Prosthetic Rehabilitation in Children: An Alternative Clinical Technique

    Directory of Open Access Journals (Sweden)

    Nádia Carolina Teixeira Marques

    2013-01-01

    Full Text Available Complete and partial removable dentures have been used successfully in numerous patients with oligodontia and/or anodontia. However, there is little information in the literature regarding the principles and guidelines to prosthetic rehabilitation for growing children. This case report describes the management of a young child with oligodontia as well as the treatment planning and the prosthetic rehabilitation technique.

  13. Prosthetic prescription in the Netherlands: An interview with clinical experts

    NARCIS (Netherlands)

    Van Der Linde, H.; Geertzen, J.H.B.; Hofstad, C.J.; van Limbeek, Jonice; Postema, K.

    2004-01-01

    In the process of guideline development for prosthetic prescription in the Netherlands the authors made a study of the daily clinical practice of lower limb prosthetics. Besides the evidence-based knowledge from literature the more implicit knowledge from clinical experts is of importance for guidel

  14. Effects of visual deprivation during brain development on expression of AMPA receptor subunits in rat’s hippocampus

    Directory of Open Access Journals (Sweden)

    Sayyed Alireza Talaei

    2015-06-01

    Conclusion: Dark rearing of rats during critical period of brain development changes the relative expression and also arrangement of both AMPA receptor subunits, GluR1 and GluR2 in the hippocampus, age dependently.

  15. Visual Evoked Potentials to Light Flashes in Captive Rhesus Monkeys: A Study Reflecting Cerebral Cortical Activity and Brain Maturation

    Directory of Open Access Journals (Sweden)

    S.A. Solís-Chávez

    2014-01-01

    Full Text Available Visual evoked potentials (VEPs are useful electrophysiological diagnostic tools for evaluating retinal response of the visual cortex and detecting its functional integrity in humans and animals. To analyze the VEPs and physiologic response of the visual pathway of a random population of captive-bred monkeys of the Macaca mulatta species throughout different physiologic stages after stimulation with stroboscopic light flashes. In this study we used 20 non-human primates (M. mulatta, 10 males and 10 females, divided into five age-dependant cohorts of 2 males and 2 females. Two replicable negative waveforms and one positive were recorded, as reliable indicators of electrical conductivity at specific anatomical nuclei of the visual pathways. Statistically significant differences were primarily observed in group 1 when compared against the remaining groups for the three evaluated waveforms. Waveform morphology characteristically presented steady deviations related to ontogenetic development of the studied population.

  16. Different visual exploration of tool-related gestures in left hemisphere brain damaged patients is associated with poor gestural imitation.

    Science.gov (United States)

    Vanbellingen, Tim; Schumacher, Rahel; Eggenberger, Noëmi; Hopfner, Simone; Cazzoli, Dario; Preisig, Basil C; Bertschi, Manuel; Nyffeler, Thomas; Gutbrod, Klemens; Bassetti, Claudio L; Bohlhalter, Stephan; Müri, René M

    2015-05-01

    According to the direct matching hypothesis, perceived movements automatically activate existing motor components through matching of the perceived gesture and its execution. The aim of the present study was to test the direct matching hypothesis by assessing whether visual exploration behavior correlate with deficits in gestural imitation in left hemisphere damaged (LHD) patients. Eighteen LHD patients and twenty healthy control subjects took part in the study. Gesture imitation performance was measured by the test for upper limb apraxia (TULIA). Visual exploration behavior was measured by an infrared eye-tracking system. Short videos including forty gestures (20 meaningless and 20 communicative gestures) were presented. Cumulative fixation duration was measured in different regions of interest (ROIs), namely the face, the gesturing hand, the body, and the surrounding environment. Compared to healthy subjects, patients fixated significantly less the ROIs comprising the face and the gesturing hand during the exploration of emblematic and tool-related gestures. Moreover, visual exploration of tool-related gestures significantly correlated with tool-related imitation as measured by TULIA in LHD patients. Patients and controls did not differ in the visual exploration of meaningless gestures, and no significant relationships were found between visual exploration behavior and the imitation of emblematic and meaningless gestures in TULIA. The present study thus suggests that altered visual exploration may lead to disturbed imitation of tool related gestures, however not of emblematic and meaningless gestures. Consequently, our findings partially support the direct matching hypothesis. PMID:25841335

  17. [FTIR spectroscopic studies of facial prosthetic adhesives].

    Science.gov (United States)

    Kang, Biao; Yang, Qing-fang; Liang, Jian-feng; Zhao, Yi-min

    2008-10-01

    According to the composition of the traditional facial prosthetic adhesives, most of adhesives can be classified into two categories: acrylic polymer-based adhesive and silicone-based adhesive. In previous studies, measurements of various mechanical bond strengths were carried out, whereas the functional groups of the adhesives were evaluated seldom during the adhesion. In the present study the analysis of two facial prosthetic adhesives (Epithane and Secure Adhesive) was carried out by using infrared spectroscopy. Two adhesives in the form of fluid or semisolid were submitted to FTIR spectroscopy, respectively. The results showed that water and ammonia residue volatilized during the solidification of Epithane, and absorption peak reduction of carbonyl was due to the volatilization of acetate vinyl from Secure Adhesive. Similar silicone functional groups both in the silicone-based adhesive and in silicone elastomer could be the key to higher bond strength between silicone elastomer and skin with silicone-based adhesive. The position, shape of main absorption peaks of three adhesives didn't change, which showing that their main chemicals and basic structures didn't change during solidification. PMID:19123392

  18. Surgical and prosthetic treatment for microphthalmia syndromes.

    Science.gov (United States)

    Wavreille, O; François Fiquet, C; Abdelwahab, O; Laumonier, E; Wolber, A; Guerreschi, P; Pellerin, P

    2013-03-01

    Our aim was to evaluate the long-term outcomes of prosthetic treatment and orbital expansion in the management of microphthalmia syndromes. We did a retrospective single-centre study of all cases of microphthalmia treated between 1989 and 2010. The patients were divided into three groups: isolated microphthalmia, microphthalmia associated with micro-orbitism, and complex microphthalmia syndrome. To evaluate the results a score was computed for each patient by assessing the length of the palpebral fissure, the depth of the conjunctival fornix, and local complications together with an evaluation of the satisfaction of patients and their families. Forty-four children were included (27 boys and 17 girls). Twenty-seven had unilateral microphthalmia (61%) and 17 bilateral microphthalmia (39%). Twelve patients were lost to follow up. The mean duration of follow-up was 12 years (range 4-21). Management involved an ocular conformer in only 31 patients (71%). The treatment was deemed satisfactory in all except 10 children. Surgical treatment with orbital expansion permitted good symmetry of the orbital cavities with a final mean difference of 9% (range 3-17) compared with the initial 16.8% (range 13.6-20.3). The prosthetic treatment gives satisfactory results. Despite limited indications and difficult follow-up, our experience emphasises the value of surgical treatment for severe micro-orbitism.

  19. Comparison of Brain Activation Images Associated with Sexual Arousal Induced by Visual Stimulation and SP6 Acupuncture: fMRI at 3 Tesla

    International Nuclear Information System (INIS)

    This study was performed not only to compare the brain activation regions associated with sexual arousal induced by visual stimulation and SP6 acupuncture, but also to evaluate its differential neuro-anatomical mechanism in healthy women using functional magnetic resonance imaging (fMRI) at 3 Tesla (T). A total of 21 healthy right-handed female volunteers (mean age 22 years, range 19 to 32) underwent fMRI on a 3T MR scanner. The stimulation paradigm for sexual arousal consisted of two alternating periods of rest and activation. It began with a 1-minute rest period, 3 minutes of stimulation with either of an erotic video film or SP6 acupuncture, followed by 1-minute rest. In addition, a comparative study on the brain activation patterns between an acupoint and a shampoint nearby GB37 was performed. The fMRI data were obtained from 20 slices parallel to the AC-PC line on an axial plane, giving a total of 2,000 images. The mean activation maps were constructed and analyzed by using the statistical parametric mapping (SPM99) software. As comparison with the shampoint, the acupoint showed 5 times and 2 times higher activities in the neocortex and limbic system, respectively. Note that brain activation in response to stimulation with the shampoint was not observed in the regions including the HTHL in the diencephalon, GLO and AMYG in the basal ganglia, and SMG in the parietal lobe. In the comparative study of visual stimulation vs. SP6 acupuncture, the mean activation ratio of stimulus was not significantly different to each other in both the neocortex and the limbic system (p < 0.05). The mean activities induced by both stimuli were not significantly different in the neocortex, whereas the acupunctural stimulation showed higher activity in the limbic system (p < 0.05). This study compared the differential brain activation patterns and the neural mechanisms for sexual arousal, which were induced by visual stimulation and SP6 acupuncture by using 3T fMRI. These findings

  20. Comparison of Brain Activation Images Associated with Sexual Arousal Induced by Visual Stimulation and SP6 Acupuncture: fMRI at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Nam Gil [Dept. of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of); Han, Jae Bok; Jang, Seong Joo [Dept. of Radiology, Dongshin University, Naju (Korea, Republic of)

    2009-06-15

    This study was performed not only to compare the brain activation regions associated with sexual arousal induced by visual stimulation and SP6 acupuncture, but also to evaluate its differential neuro-anatomical mechanism in healthy women using functional magnetic resonance imaging (fMRI) at 3 Tesla (T). A total of 21 healthy right-handed female volunteers (mean age 22 years, range 19 to 32) underwent fMRI on a 3T MR scanner. The stimulation paradigm for sexual arousal consisted of two alternating periods of rest and activation. It began with a 1-minute rest period, 3 minutes of stimulation with either of an erotic video film or SP6 acupuncture, followed by 1-minute rest. In addition, a comparative study on the brain activation patterns between an acupoint and a shampoint nearby GB37 was performed. The fMRI data were obtained from 20 slices parallel to the AC-PC line on an axial plane, giving a total of 2,000 images. The mean activation maps were constructed and analyzed by using the statistical parametric mapping (SPM99) software. As comparison with the shampoint, the acupoint showed 5 times and 2 times higher activities in the neocortex and limbic system, respectively. Note that brain activation in response to stimulation with the shampoint was not observed in the regions including the HTHL in the diencephalon, GLO and AMYG in the basal ganglia, and SMG in the parietal lobe. In the comparative study of visual stimulation vs. SP6 acupuncture, the mean activation ratio of stimulus was not significantly different to each other in both the neocortex and the limbic system (p < 0.05). The mean activities induced by both stimuli were not significantly different in the neocortex, whereas the acupunctural stimulation showed higher activity in the limbic system (p < 0.05). This study compared the differential brain activation patterns and the neural mechanisms for sexual arousal, which were induced by visual stimulation and SP6 acupuncture by using 3T fMRI. These findings

  1. Visual motion-sensitive neurons in the bumblebee brain convey information about landmarks during a navigational task

    Directory of Open Access Journals (Sweden)

    Marcel eMertes

    2014-09-01

    Full Text Available Bees use visual memories to find the spatial location of previously learnt food sites. Characteristic learning flights help acquiring these memories at newly discovered foraging locations where landmarks - salient objects in the vicinity of the goal location - can play an important role in guiding the animal’s homing behavior. Although behavioral experiments have shown that bees can use a variety of visual cues to distinguish objects as landmarks, the question of how landmark features are encoded by the visual system is still open. Recently, it could be shown that motion cues are sufficient to allow bees localizing their goal using landmarks that can hardly be discriminated from the background texture. Here, we tested the hypothesis that motion sensitive neurons in the bee’s visual pathway provide information about such landmarks during a learning flight and might, thus, play a role for goal localization. We tracked learning flights of free-flying bumblebees (Bombus terrestris in an arena with distinct visual landmarks, reconstructed the visual input during these flights, and replayed ego-perspective movies to tethered bumblebees while recording the activity of direction-selective wide-field neurons in their optic lobe. By comparing neuronal responses during a typical learning flight and targeted modifications of landmark properties in this movie we demonstrate that these objects are indeed represented in the bee’s visual motion pathway. We find that object-induced responses vary little with object texture, which is in agreement with behavioral evidence. These neurons thus convey information about landmark properties that are useful for view-based homing.

  2. Abnormal MEG oscillatory activity during visual processing in the prefrontal cortices and frontal eye-fields of the aging HIV brain.

    Directory of Open Access Journals (Sweden)

    Tony W Wilson

    Full Text Available OBJECTIVE: Shortly after infection, HIV enters the brain and causes widespread inflammation and neuronal damage, which ultimately leads to neuropsychological impairments. Despite a large body of neuroscience and imaging studies, the pathophysiology of these HIV-associated neurocognitive disorders (HAND remains unresolved. Previous neuroimaging studies have shown greater activation in HIV-infected patients during strenuous tasks in frontal and parietal cortices, and less activation in the primary sensory cortices during rest and sensory stimulation. METHODS: High-density magnetoencephalography (MEG was utilized to evaluate the basic neurophysiology underlying attentive, visual processing in older HIV-infected adults and a matched non-infected control group. Unlike other neuroimaging methods, MEG is a direct measure of neural activity that is not tied to brain metabolism or hemodynamic responses. During MEG, participants fixated on a centrally-presented crosshair while intermittent visual stimulation appeared in their top-right visual-field quadrant. All MEG data was imaged in the time-frequency domain using beamforming. RESULTS: Uninfected controls had increased neuronal synchronization in the 6-12 Hz range within the right dorsolateral prefrontal cortex, right frontal eye-fields, and the posterior cingulate. Conversely, HIV-infected patients exhibited decreased synchrony in these same neural regions, and the magnitude of these decreases was correlated with neuropsychological performance in several cortical association regions. CONCLUSIONS: MEG-based imaging holds potential as a noninvasive biomarker for HIV-related neuronal dysfunction, and may help identify patients who have or may develop HAND. Reduced synchronization of neural populations in the association cortices was strongly linked to cognitive dysfunction, and likely reflects the impact of HIV on neuronal and neuropsychological health.

  3. Abnormal brain activation in neurofibromatosis type 1: a link between visual processing and the default mode network.

    Directory of Open Access Journals (Sweden)

    Inês R Violante

    Full Text Available Neurofibromatosis type 1 (NF1 is one of the most common single gene disorders affecting the human nervous system with a high incidence of cognitive deficits, particularly visuospatial. Nevertheless, neurophysiological alterations in low-level visual processing that could be relevant to explain the cognitive phenotype are poorly understood. Here we used functional magnetic resonance imaging (fMRI to study early cortical visual pathways in children and adults with NF1. We employed two distinct stimulus types differing in contrast and spatial and temporal frequencies to evoke relatively different activation of the magnocellular (M and parvocellular (P pathways. Hemodynamic responses were investigated in retinotopically-defined regions V1, V2 and V3 and then over the acquired cortical volume. Relative to matched control subjects, patients with NF1 showed deficient activation of the low-level visual cortex to both stimulus types. Importantly, this finding was observed for children and adults with NF1, indicating that low-level visual processing deficits do not ameliorate with age. Moreover, only during M-biased stimulation patients with NF1 failed to deactivate or even activated anterior and posterior midline regions of the default mode network. The observation that the magnocellular visual pathway is impaired in NF1 in early visual processing and is specifically associated with a deficient deactivation of the default mode network may provide a neural explanation for high-order cognitive deficits present in NF1, particularly visuospatial and attentional. A link between magnocellular and default mode network processing may generalize to neuropsychiatric disorders where such deficits have been separately identified.

  4. Predicting prosthetic prescription after major lower-limb amputation

    Directory of Open Access Journals (Sweden)

    Linda Resnik, PT, PhD, OCS

    2015-09-01

    Full Text Available We describe prosthetic limb prescription in the first year following lower-limb amputation and examine the relationship between amputation level, geographic region, and prosthetic prescription. We analyzed 2005 to 2010 Department of Veterans Affairs (VA Inpatient and Medical Encounters SAS data sets, Vital Status death data, and National Prosthetic Patient Database data for 9,994 Veterans who underwent lower-limb amputation at a VA hospital. Descriptive statistics and bivariates were examined. Cox proportional hazard models identified factors associated with prosthetic prescription. Analyses showed that amputation level was associated with prosthetic prescription. The hazard ratios (HRs were 1.41 for ankle amputation and 0.46 for transfemoral amputation compared with transtibial amputation. HRs for geographic region were Northeast = 1.49, Upper Midwest = 1.26, and West = 1.39 compared with the South (p < 0.001. African American race, longer length of hospital stay, older age, congestive heart failure, paralysis, other neurological disease, renal failure, and admission from a nursing facility were negatively associated with prosthetic prescription. Being married was positively associated. After adjusting for patient characteristics, people with ankle amputation were most likely to be prescribed a prosthesis and people with transfemoral amputation were least likely. Geographic variation in prosthetic prescription exists in the VA and further research is needed to explain why.

  5. Predicting prosthetic prescription after major lower-limb amputation.

    Science.gov (United States)

    Resnik, Linda; Borgia, Matthew

    2015-01-01

    We describe prosthetic limb prescription in the first year following lower-limb amputation and examine the relationship between amputation level, geographic region, and prosthetic prescription. We analyzed 2005 to 2010 Department of Veterans Affairs (VA) Inpatient and Medical Encounters SAS data sets, Vital Status death data, and National Prosthetic Patient Database data for 9,994 Veterans who underwent lower-limb amputation at a VA hospital. Descriptive statistics and bivariates were examined. Cox proportional hazard models identified factors associated with prosthetic prescription. Analyses showed that amputation level was associated with prosthetic prescription. The hazard ratios (HRs) were 1.41 for ankle amputation and 0.46 for transfemoral amputation compared with transtibial amputation. HRs for geographic region were Northeast = 1.49, Upper Midwest = 1.26, and West = 1.39 compared with the South (p length of hospital stay, older age, congestive heart failure, paralysis, other neurological disease, renal failure, and admission from a nursing facility were negatively associated with prosthetic prescription. Being married was positively associated. After adjusting for patient characteristics, people with ankle amputation were most likely to be prescribed a prosthesis and people with transfemoral amputation were least likely. Geographic variation in prosthetic prescription exists in the VA and further research is needed to explain why. PMID:26562228

  6. Qualitative and quantitative measurement of brain activity associated with visual sexual arousal in males and females: 3.0 tesIa functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Joong; Jeong, Gwang Woo; Eun, Sung Jong; Cho, Seong Hoon; Seo, Jeong Jin; Kang, Heoung Keun; Park, Kwang Sung [School of Medicine, Chonnam National Univ., Gwangju (Korea, Republic of)

    2004-08-01

    The present study utilized 3.0 Tesla functional MR imaging to identify and quantify the activated brain regions associated with visually evoked sexual arousal, and also to discriminate the gender differences between the cortical activation patterns in response to sexual stimuli. A total of 24 healthy, right-handed volunteers, 14 males (mean age: 24) and 10 females (mean age: 23), with normal heterosexual function underwent functional MRI on a 3.0T MR scanner (Forte, Isole technique, Korea). The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 3- minute stimulation by an erotic video film, and concluded with a 1-minute rest. The fMRI data was obtained from 20 slices (5 mm slice thickness, no gap) parallel to the AC-PC (anterior commissure and posterior commissure) line on the sagittal plane, giving a total of 2,100 images. The brain activation maps and the resulting quantification were analyzed by the statistical parametric mapping program, SPM 99. The mean-activated images were obtained from each individual activation map using one sampled t-test. The FALBA program, which is a new algorithm based on the pixel differentiation method, was used to identify and quantify the brain activation and lateralization indices with respect to the functional and anatomical terms. In both male and female volunteers, significant brain activation showed in the limbic areas of the parahippocampal gyrus, septal area, cingulate gyrus and thalamus. It is interesting to note that the septal areas gave a relatively lower activation ratio with high brain activities. On the contrary, the putamen, insula cortex, and corpus callosum gave a higher activation ratio with low brain activities. In particular, brain activation in the septal area, which was not reported in the previous fMRI studies under 1.5 Tesla, represents a distinct finding of this study using 3.0T MR scanner. The overall lateralization index of activation shows left predominance (LI= 35.3%) in

  7. Steady-state motion visual evoked potentials produced by oscillating Newton's rings: implications for brain-computer interfaces.

    Directory of Open Access Journals (Sweden)

    Jun Xie

    Full Text Available In this study, we utilize a special visual stimulation protocol, called motion reversal, to present a novel steady-state motion visual evoked potential (SSMVEP-based BCI paradigm that relied on human perception of motions oscillated in two opposite directions. Four Newton's rings with the oscillating expansion and contraction motions served as visual stimulators to elicit subjects' SSMVEPs. And four motion reversal frequencies of 8.1, 9.8, 12.25 and 14 Hz were tested. According to Canonical Correlation Analysis (CCA, the offline accuracy and ITR (mean ± standard deviation over six healthy subjects were 86.56 ± 9.63% and 15.93 ± 3.83 bits/min, respectively. All subjects except one exceeded the level of 80% mean accuracy. Circular Hotelling's T-Squared test (T2 circ also demonstrated that most subjects exhibited significantly strong stimulus-locked SSMVEP responses. The results of declining exponential fittings exhibited low-adaptation characteristics over the 100-s stimulation sequences in most experimental conditions. Taken together, these results suggest that the proposed paradigm can provide comparable performance with low-adaptation characteristic and less visual discomfort for BCI applications.

  8. Brain circuits underlying visual stability across eye movements - converging evidence for a neuro-computational model of area LIP

    Directory of Open Access Journals (Sweden)

    Arnold eZiesche

    2014-03-01

    Full Text Available The understanding of the subjective experience of a visually stable world despite the occurrence of an observer's eye movements has been the focus of extensive research for over 20 years. These studies have revealed fundamental mechanisms such as anticipatory receptive field shifts and the saccadic suppression of stimulus displacements, yet there currently exists no single explanatory framework for these observations. We show that a previously presented neuro-computational model of peri-saccadic mislocalization accounts for the phenomenon of predictive remapping and for the observation of saccadic suppression of displacement (SSD. This converging evidence allows us to identify the potential ingredients of perceptual stability that generalize beyond different data sets in a formal physiology-based model. In particular we propose that predictive remapping stabilizes the visual world across saccades by introducing a feedback loop and, as an emergent result, small displacements of stimuli are not noticed by the visual system. The model provides a link from neural dynamics, to neural mechanism and finally to behavior, and thus offers a testable comprehensive framework of visual stability.

  9. Visual and SPM analysis of regional cerebral perfusion with Tc-99m ECD brain SPECT in patients with developmental language disorder

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Joon Kee; Lee, Myung Hoon; Joh, Chul Woo; Yoon, Seok Nam; Oh, Eun Young [College of Medicine, Univ. of Ajou, Suwon (Korea, Republic of)

    2003-07-01

    Developmental language disorder (DLD) refers to inadequate language acquisition at the expected age in children with otherwise normal development. However, language delay can be observed in patients with other developmental disoder (ODD). We, therefore, evaluated regional cerebral perfusion pattern in patients with DLD and ODD by means of visual and SPM analysis. Twelve patients, who underwent Tc-99m ECD brain SPECT within 3 weeks of their first visit, were included in the study. Psychological and language tests classified the patients into 2 groups ; 6 with DLD (3-7 yr, 5 male and I female) and 6 with ODD (2-6 yr, 6 male). Visual analysis for regional cerebral perfusion was done in each patient. SPM with 7 controls (age=7) was performed to evaluate difference between 2 groups using t-test. P value of less than 0.005 was considered to be significant. All patients had significant language delay for their age (9 month 3.5 yr). Among 6 patients with ODD, 4 had pervasive developmental disorder, 1 mental retardation and 1 attachment disorder. Visual analysis revealed significant perfusion decrease in only 1 patient with DLD and 2 with ODD ; the regions were left parieto-temporal cortex, both frontal and cerebellar cortices, and right temporal cortex respectively. Nine of 12 patients showed normal perfusion. SPM demonstrated perfusion decrease in left inferior frontal cortex and left superior parietal cortex (Wernicke's area) in patients with DLD, while, in patients with ODD, perfusion decrease was mostly located in the right hemisphere (lateral frontoorbital gyrus, occipitotemporal gyrus, cuneus and cerebellum). Corpus callosum showed no significant perfusion abnormality in both groups. Regional cerebral perfusion of patients with DLD, which was mainly located in the speech area, is quite different from that of ODD-patients with language delay. While SPM successfully revealed this difference in perfusion pattern, visual analysis had limited value.

  10. A Miniature Force Sensor for Prosthetic Hands

    Science.gov (United States)

    Platt, Robert; Chu, Mars; Diftler, Myron; Martin, Toby; Valvo, Michael

    2006-01-01

    Tactile sensing is an important part of the development of new prosthetic hands. A number of approaches to establishing an afferent pathway back to the patient for tactile information are becoming available including tactors and direct stimulation of the afferent nerves. Tactile information can also be used by low-level control systems that perform simple tasks for the patient such as establishing a stable grasp and maintaining the grasping forces needed to hold an object. This abstract reports on the design of a small fingertip load cell based on semi-conductor strain gauges. Since this load cell is so small (measuring only 8.5mm in diameter and 6.25 mm in height), it easily fits into the tip of an anthropomorphic mechatronic hand. This load cell is tested by comparing a time series of force and moment data with reference data acquired from a much larger high-precision commercial load cell.

  11. Upper limb prosthetic use in Slovenia.

    Science.gov (United States)

    Burger, H; Marincek, C

    1994-04-01

    The article deals with the use of different types of upper limb prostheses in Slovenia. Four hundred and fourteen upper limb amputees were sent a questionnaire on the type of their prosthesis, its use and reasons for non-use, respectively. The replies were subject to statistical analysis. Most of the questioned upper limb amputees (70%) wear a prosthesis only for cosmesis. The use of a prosthesis depends on the level of upper limb amputation, loss of the dominant hand, and time from amputation. Prosthetic success appears to be unrelated to age at the time of amputation and the rehabilitation programme. The most frequent reason for not wearing a prosthesis is heat and consequent sweating of the stump. More than a third of amputees are dissatisfied with their prostheses.

  12. Aberrant Early Visual Neural Activity and Brain-Behavior Relationships in Anorexia Nervosa and Body Dysmorphic Disorder

    Directory of Open Access Journals (Sweden)

    Wei eLi

    2015-06-01

    Full Text Available Background:Body dysmorphic disorder (BDD and anorexia nervosa (AN share the clinical symptom of disturbed body image, which may be a function of perceptual distortions. Previous studies suggest visual or visuospatial processing abnormalities may be contributory, but have been unable to discern whether these occur early or late in the visual processing stream. We used electroencephalography (EEG and visual event related potentials (ERP to investigate early perceptual neural activity associated with processing visual stimuli.Methods:We performed EEG on 20 AN, 20 BDD, 20 healthy controls, all unmedicated. In order to probe configural/holistic and detailed processing, participants viewed photographs of faces and houses that were unaltered or filtered to low or high spatial frequencies, respectively. We calculated the early ERP components P100 and N170, and compared amplitudes and latencies among groups.Results:P100 amplitudes were smaller in AN than BDD and healthy controls, regardless of spatial frequency or stimulus type (faces or houses. Similarly, N170 latencies were longer in AN than healthy controls, regardless of spatial frequency or stimulus type, with a similar pattern in BDD at trend level significance. N170 amplitudes were smaller in AN than controls for high and normal spatial frequency images, and smaller in BDD than controls for normal spatial frequency images, regardless of stimulus type. Poor insight correlated with lower N170 amplitudes for normal and low spatial frequency faces in the BDD group.Conclusions:Individuals with AN exhibit abnormal early visual system activity, consistent with reduced configural processing and enhanced detailed processing. This is evident regardless of whether the stimuli are appearance- or non appearance-related, and thus may be a reflection of general, early perceptual abnormalities. As N170 amplitude could be a marker of structural encoding of faces, lower values may be associated with perceptual dis

  13. Gait analysis in lower-limb amputation and prosthetic rehabilitation.

    Science.gov (United States)

    Esquenazi, Alberto

    2014-02-01

    Gait analysis combined with sound clinical judgment plays an important role in elucidating the factors involved in the pathologic prosthetic gait and the selection and effects of available interventions to optimize it. Detailed clinical evaluation of walking contributes to the analysis of the prosthetic gait, but evaluation in the gait laboratory using kinetic and kinematic data is often necessary to quantify and identify the particular contributions of the variables impacting the gait with confidence and assess the results of such intervention. The same approach can be considered when selecting prosthetic components and assessing leg length in this patient population.

  14. Exercise increases blood flow to locomotor, vestibular, cardiorespiratory and visual regions of the brain in miniature swine

    Science.gov (United States)

    Delp, M. D.; Armstrong, R. B.; Godfrey, D. A.; Laughlin, M. H.; Ross, C. D.; Wilkerson, M. K.

    2001-01-01

    1. The purpose of these experiments was to use radiolabelled microspheres to measure blood flow distribution within the brain, and in particular to areas associated with motor function, maintenance of equilibrium, cardiorespiratory control, vision, hearing and smell, at rest and during exercise in miniature swine. Exercise consisted of steady-state treadmill running at intensities eliciting 70 and 100 % maximal oxygen consumption (V(O(2),max)). 2. Mean arterial pressure was elevated by 17 and 26 % above that at rest during exercise at 70 and 100 % V(O(2),max), respectively. 3. Mean brain blood flow increased 24 and 25 % at 70 and 100 % V(O(2),max), respectively. Blood flow was not locally elevated to cortical regions associated with motor and somatosensory functions during exercise, but was increased to several subcortical areas that are involved in the control of locomotion. 4. Exercise elevated perfusion and diminished vascular resistance in several regions of the brain related to the maintenance of equilibrium (vestibular nuclear area, cerebellar ventral vermis and floccular lobe), cardiorespiratory control (medulla and pons), and vision (dorsal occipital cortex, superior colliculi and lateral geniculate body). Conversely, blood flow to regions related to hearing (cochlear nuclei, inferior colliculi and temporal cortex) and smell (olfactory bulbs and rhinencephalon) were unaltered by exercise and associated with increases in vascular resistance. 5. The data indicate that blood flow increases as a function of exercise intensity to several areas of the brain associated with integrating sensory input and motor output (anterior and dorsal cerebellar vermis) and the maintenance of equilibrium (vestibular nuclei). Additionally, there was an intensity-dependent decrease of vascular resistance in the dorsal cerebellar vermis.

  15. Plasma Concentration of Prolactin, Testosterone Might Be Associated with Brain Response to Visual Erotic Stimuli in Healthy Heterosexual Males

    OpenAIRE

    Seo, Younghee; Jeong, Bumseok; Kim, Ji-Woong; Choi, Jeewook

    2009-01-01

    Objective Many studies have showed that excess or lack of sexual hormones, such as prolactin and testosterone, induced the sexual dysfunction in humans. Little, however, is known about the role of sexual hormones showing normal range in, especially, the basal state unexposed to any sexual stimulation. We hypothesized sexual hormones in the basal state may affect sexual behavior. Methods We investigated the association of the sexual hormones level in the basal hormonal state before visual sexu...

  16. Brain circuits underlying visual stability across eye movements-converging evidence for a neuro-computational model of area LIP

    OpenAIRE

    Arnold Ziesche; Hamker, Fred H.

    2014-01-01

    The understanding of the subjective experience of a visually stable world despite the occurrence of an observer's eye movements has been the focus of extensive research for over 20 years. These studies have revealed fundamental mechanisms such as anticipatory receptive field (RF) shifts and the saccadic suppression of stimulus displacements, yet there currently exists no single explanatory framework for these observations. We show that a previously presented neuro-computational model of peri-...

  17. Different contributions of visual and motor brain areas during liking judgments of same- and different-gender bodies.

    Science.gov (United States)

    Cazzato, V; Mele, S; Urgesi, C

    2016-09-01

    Previous neuroimaging studies have shown that body aesthetic appreciation involves the activation of both visual and motor areas, supporting a role of sensorimotor embodiment in aesthetic processing. Causative evidence, however, that neural activity in these areas is crucial for reliable aesthetic body appreciation has so far provided only for extrastriate body area (EBA), while the functional role played by premotor regions remained less clear. Here, we applied short trains of repetitive transcranial magnetic stimulation (rTMS) over bilateral dorsal premotor cortex (dPMC) and EBA during liking judgments of female and male bodies varying in weight and implied motion. We found that both dPMC and EBA are necessary for aesthetic body appreciation, but their relative contribution depends on the model's gender. While dPMC-rTMS decreased the liking judgments of same-, but not of different-gender models, EBA-rTMS increased the liking judgments of different-, but not of same-gender models. Relative contributions of motor and visual areas may reflect processing of diverse aesthetic properties, respectively implied motion vs. body form, and/or greater sensorimotor embodiment of same- vs. different-gender bodies. Results suggest that aesthetic body processing is subserved by a network of motor and visual areas, whose relative contribution may depend on the specific stimulus and task. PMID:27235869

  18. Two-degree-of-freedom powered prosthetic wrist

    Directory of Open Access Journals (Sweden)

    Peter J. Kyberd, PhD

    2011-07-01

    Full Text Available Prosthetic wrists need to be compact. By minimizing space requirements, a wrist unit can be made for people with long residual limbs. This prosthetic wrist uses two motors arranged across the arm within the envelope of the hand. The drive is transmitted by a differential so that it produces wrist flexion and extension, pronation and supination, or a combination of both. As a case study, it was controlled by a single-prosthesis user with pattern recognition of the myoelectric signals from the forearm. The result is a compact, two-degree-of-freedom prosthetic wrist that has the potential to improve the functionality of any prosthetic hand by creating a hand orientation that more closely matches grasp requirements.

  19. Prosthetic Knee Septic Arthritis due to Pseudomonas stutzeri

    Directory of Open Access Journals (Sweden)

    Jihad Bishara

    2000-01-01

    Full Text Available Prosthetic joint infection is usually caused by Staphylococcus aureus, coagulase-negative staphylococci and, less commonly, by Gram-negative bacilli and anaerobes. A case of prosthetic joint infection due to Pseudomonas stutzeri in a 73-year-old female with acute promyelocytic leukemia is presented, and the pertinent literature is reviewed. Although the patient had prolonged neutropenia, the infection was successfully treated with antibiotics and without artificial joint replacement.

  20. ORAL HYGIENE OF PROSTHETIC DENTURE USER IN KODINGARENG ISLAND

    OpenAIRE

    NUR, NURUL KUSUMADEWI S.KG

    2008-01-01

    Objectives:to determine the level of oral hygiene for prosthetic denture user, especially for full-denture in Kodingareng Island. This researchincluded the distribution level of prosthetic denture user based on age and education.Methods: the method that used in this research is observational descriptive withcross sectional-studyas the research design. Variable result of the research determined in to 3, those are bad, middle, and good. Result:the highest percentage o...

  1. Rotationplasty with Vascular Reconstruction for Prosthetic Knee Joint Infection

    Directory of Open Access Journals (Sweden)

    Masahide Fujiki

    2015-01-01

    Full Text Available Rotationplasty is used most often as a function-preserving salvage procedure after resection of sarcomas of the lower extremity; however, it is also used after infection of prosthetic knee joints. Conventional vascular management during rotationplasty is to preserve and coil major vessels, but recently, transection and reanastomosis of the major vessels has been widely performed. However, there has been little discussion regarding the optimal vascular management of rotationplasty after infection of prosthetic knee joints because rotationplasty is rarely performed for this indication. We reviewed four patients who had undergone resection of osteosarcomas of the femur, placement of a prosthetic knee joint, and rotationplasty with vascular reconstruction from 2010 to 2013. The mean interval between prosthetic joint replacement and rotationplasty was 10.4 years and the mean interval between the diagnosis of prosthesis infection and rotationplasty was 7.9 years. Rotationplasty was successful in all patients; however, in one patient, arterial thrombosis developed and necessitated urgent surgical removal and arterial reconstruction. All patients were able to walk independently with a prosthetic limb after rehabilitation. Although there is no consensus regarding the most appropriate method of vascular management during rotationplasty for revision of infected prosthetic joints, vascular transection and reanastomosis is a useful option.

  2. Predicting prosthetic prescription after major lower-limb amputation.

    Science.gov (United States)

    Resnik, Linda; Borgia, Matthew

    2015-01-01

    We describe prosthetic limb prescription in the first year following lower-limb amputation and examine the relationship between amputation level, geographic region, and prosthetic prescription. We analyzed 2005 to 2010 Department of Veterans Affairs (VA) Inpatient and Medical Encounters SAS data sets, Vital Status death data, and National Prosthetic Patient Database data for 9,994 Veterans who underwent lower-limb amputation at a VA hospital. Descriptive statistics and bivariates were examined. Cox proportional hazard models identified factors associated with prosthetic prescription. Analyses showed that amputation level was associated with prosthetic prescription. The hazard ratios (HRs) were 1.41 for ankle amputation and 0.46 for transfemoral amputation compared with transtibial amputation. HRs for geographic region were Northeast = 1.49, Upper Midwest = 1.26, and West = 1.39 compared with the South (p amputation were most likely to be prescribed a prosthesis and people with transfemoral amputation were least likely. Geographic variation in prosthetic prescription exists in the VA and further research is needed to explain why.

  3. Visualization of the air ejected from the temporary cavity in brain and tissue simulants during gunshot wounding.

    Science.gov (United States)

    Lazarjan, M S; Geoghegan, P H; Taylor, M C; Jermy, M C

    2015-01-01

    One hypothesis for the physical mechanism responsible for backspatter during cranial gunshot wounding is that air is ejected by the collapse of the temporary cavity formed around the bullet path. Using bovine and ovine heads and simulant materials, evidence of this ejection was sought by measuring the velocity of the air that was drawn in and ejected from the cavity in front of the wound channel after bullet impact. A laminar flow of fog-laden air was arranged in front of the wound channel and two high speed cameras recording at 30,000 frames/second captured the air motion. All samples were shot with standard 9 mm × 19 mm FMJ ammunition. Different concentrations of ballistic gelatine were used to characterize the effect of elasticity of the material on the velocity of the air. Fresh bovine and ovine heads were shot with the same experimental set up to investigate if there was induction of air into, and ejection of air from the entrance wounds. The results show, for the first time, that the temporary cavity does eject air in gelatine. The velocity of in-drawn air for 3, 5 and 10% concentration of gelatine was 81, 76 and 65 m/s respectively and the velocity of ejected air for 5 and 10% concentration of gelatine were 43 and 72 m/s respectively. The results show that when the concentration of gelatine is increased, the velocity of the air drawn into the cavity decreases and the velocity of the ejected air increases. However, no ejection was observed in 3% gelatine, ovine or bovine heads. Although ejection of air was not observed, ejection of brain from the wound channel was seen. Using the velocity of the ejected brain, the minimum intracranial pressure required to eject the brain tissue was estimated to be 712 kPa and 468 kPa for the sheep and bovine heads respectively. PMID:25485950

  4. [Complex partial status epilepticus with recurrent episodes of complex visual hallucinations: study by using 123I-IMP-SPECT, brain MRI and EEG].

    Science.gov (United States)

    Sakai, Toshiyuki; Kondo, Masahide; Tomimoto, Hidekazu

    2015-01-01

    We report a 72-year-old woman with complex partial status epilepticus who showed recurrent episodes of complex visual hallucinations (CVH). Brain diffusion-weighted magnetic resonance images revealed gyriform cortical hyperintensity in the right parietal, occipital and temporal lobes, and brain magnetic resonance angiograhy revealed a hyperintensity in the right dilated middle cerebral artery during ictal period. Ictal N-isopropyl-p-(iodine-123)-iodoamphetamine single photon emission computed tomography (123I-IMP-SPECT) with three-dimensional stereotactic surface projection (3D-SSP) 14 days after the onset of the first CVH revealed hyperperfusion in the right latero-inferior occipito-temporal region with relation to motion. CVH spontaneously subsided 17 days after the onset of the first CVH. CVH recurred one year after the first CVH. Ictal 123I-IMP-SPECT with 3D-SSP revealed marked hyperperfusion in the right lateral parietal region probably with relation to face and figure hallucinations. Ictal scalp EEGs revealed rhythmic polyspikes at 12 Hz with high amplitude (100-200 μV) in bilateral posterior occipital and temporal region with the right side dominance for 20 seconds and more in several occasions. Interictal 123I-IMP-SPECT with 3D-SSP 28 days after recurrence of CVH revealed marked hypoperfusion in the right lateral parietal region, and recovery of hypoperfusion in the right latero-inferior occipito-temporal region. These findings suggest that ictal CVH might be induced by the spread of epileptic discharges from the right parieto-occipito-temporal region with the old brain contusion (epileptogenic region) to the right latero-inferior occipito-temporal region and the right lateral parietal region (symptomatogenic regions).

  5. Comparison of tactile, auditory and visual modality for brain-computer interface use: A case study with a patient in the locked-in state

    Directory of Open Access Journals (Sweden)

    Tobias eKaufmann

    2013-07-01

    Full Text Available This paper describes a case study with a patient in the classic locked-in state, who currently has no means of independent communication. Following a user-centered approach, we investigated event-related potentials elicited in different modalities for use in brain-computer interface systems. Such systems could provide her with an alternative communication channel. To investigate the most viable modality for achieving BCI based communication, classic oddball paradigms (1 rare and 1 frequent stimulus, ratio 1:5 in the visual, auditory and tactile modality were conducted (2 runs per modality. Classifiers were built on one run and tested offline on another run (and vice versa. In these paradigms, the tactile modality was clearly superior to other modalities, displaying high offline accuracy even when classification was performed on single trials only. Consequently, we tested the tactile paradigm online and the patient successfully selected targets without any error. Furthermore, we investigated use of the visual or tactile modality for different BCI systems with more than two selection options. In the visual modality, several BCI paradigms were tested offline. Neither matrix-based nor so-called gaze-independent paradigms constituted a means of control. These results may thus question the gaze-independence of current gaze-independent approaches to BCI. A tactile four-choice BCI resulted in high offline classification accuracies. Yet, online use raised various issues. Although performance was clearly above chance, practical daily life use appeared unlikely when compared to other communication approaches (e.g. partner scanning. Our results emphasize the need for user-centered design in BCI development including identification of the best stimulus modality for a particular user. Finally, the paper discusses feasibility of EEG-based BCI systems for patients in classic locked-in state and compares BCI to other AT solutions that we also tested during the

  6. The Effectiveness of Visual Short-Time Neurofeedback on Brain Activity and Clinical Characteristics in Alcohol Use Disorders: Practical Issues and Results.

    Science.gov (United States)

    Lackner, Nina; Unterrainer, Human F; Skliris, Dimitris; Wood, Guilherme; Wallner-Liebmann, Sandra J; Neuper, Christa; Gruzelier, John H

    2016-07-01

    The present study was carried out to examine the efficacy of alpha/theta neurofeedback (NF) with a new visual paradigm in a cohort of alcohol use disordered (AUD) patients (n = 25) treated in an Austrian therapeutic community center. The experimental study design focused on changes in absolute and relative resting EEG band power as well as in clinical variables, including depression (Beck Depresion Inventory [BDI-V]), psychiatric symptoms (Brief Symptom Inventory [BSI], coping (Freiburg Questionnaire on Coping with Illness [FKV-lis]), psychotherapy motivation (Therapy Motivation Questionnaire [FPTM-23]), sense of coherence (Sense of Coherence Scale [SOC-13]), posttraumatic growth (Posttraumatic Growth Inventory [PPR]), and alcohol cravings (Alcohol Craving Questionnaire [ACQ]). For measuring training effects, participants were randomly allocated to 2 groups: an experimental group (EG, n = 13) and a control group (CG, n = 12). Patients in EG received 12 sessions of visual NF training over a period of 6 weeks to enhance alpha (8-12 Hz) and theta (4-7 Hz) frequency band power in addition to the standard treatment program of the rehabilitation center. Participants in CG received no additional NF intervention. The multivariate analysis of covariance (MANCOVA) showed a change by trend in absolute alpha and theta power in the EG. Even though no MANCOVA effects were found in the clinical scales, AUD patients reported increasing control of their brain activity during the course of NF. However, changes in several clinical scales (BDI-V, BSI, FKV-lis, PPR) from pre- to posttest were observed only in the EG contrary to the CG. The findings of this pilot study provide first evidence for the practicality and effectiveness of visual short-term NF as an additive intervention in the therapeutic community. PMID:26415612

  7. Dental Prosthetic Status and Prosthetic Needs of Institutionalised Elderly Population in Oldage Homes of Jabalpur City, Madhya Pradesh, India

    OpenAIRE

    Deogade, Suryakant C.; Vinay, S.; Naidu, Sonal

    2012-01-01

    Oral disorders are cumulative throughout life and hence unfavourable outcomes are likely to be greatest among the elderly. A descriptive cross-sectional study was conducted among institutionalized geriatric population in old-age homes of Jabalpur city, Madhya Pradesh, to assess their prosthetic status and prosthetic needs. A cross-sectional survey was conducted in all the four old-age homes of Jabalpur city, Madhya Pradesh state, India. All residents aged 60 years and above formed the study p...

  8. Direct Visualization of Neurotransmitters in Rat Brain Slices by Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI - MS)

    Science.gov (United States)

    Fernandes, Anna Maria A. P.; Vendramini, Pedro H.; Galaverna, Renan; Schwab, Nicolas V.; Alberici, Luciane C.; Augusti, Rodinei; Castilho, Roger F.; Eberlin, Marcos N.

    2016-10-01

    Mass spectrometry imaging (MSI) of neurotransmitters has so far been mainly performed by matrix-assisted laser desorption/ionization (MALDI) where derivatization reagents, deuterated matrix and/or high resolution, or tandem MS have been applied to circumvent problems with interfering ion peaks from matrix and from isobaric species. We herein describe the application of desorption electrospray ionization mass spectrometry imaging (DESI)-MSI in rat brain coronal and sagittal slices for direct spatial monitoring of neurotransmitters and choline with no need of derivatization reagents and/or deuterated materials. The amino acids γ-aminobutyric (GABA), glutamate, aspartate, serine, as well as acetylcholine, dopamine, and choline were successfully imaged using a commercial DESI source coupled to a hybrid quadrupole-Orbitrap mass spectrometer. The spatial distribution of the analyzed compounds in different brain regions was determined. We conclude that the ambient matrix-free DESI-MSI is suitable for neurotransmitter imaging and could be applied in studies that involve evaluation of imbalances in neurotransmitters levels.

  9. Structural brain abnormalities in patients with Parkinson's disease with visual hallucinations: a comparative voxel-based analysis.

    Science.gov (United States)

    Gama, Romulo Lopes; Bruin, Veralice Meireles Sales; Távora, Daniel Gurgel Fernandes; Duran, Fábio L S; Bittencourt, Lia; Tufik, Sergio

    2014-06-01

    The objective is to evaluate clinical characteristics and cerebral alterations in Parkinson's disease (PD) patients with diurnal visual hallucinations (VHs). Assessment was performed using magnetic resonance image (MRI) and voxel-based morphometry (VBM). Thirty-nine patients with PD (53.8%) and ten controls were studied. Voxel based morphology analysis was performed. Eleven patients presented diurnal VHs and among these, six had cognitive dysfunction. Patients with VHs performed worse in the mentation-related UPDRS I (p=0.005) and motor-related UPDRS III (p=0.02). Patients with VHs showed significant clusters of reduced grey matter volume compared to controls in the left opercula frontal gyrus and left superior frontal gyrus. PD without hallucinations demonstrated reduced grey matter volume in the left superior frontal gyrus compared to controls. Comparisons between patients with VHs regarding the presence of cognitive dysfunction showed that cases with cognitive dysfunction as compared to those without cognitive dysfunction showed significant clusters of reduced grey matter volume in the left opercular frontal gyrus. Cases without cognitive dysfunction had reduced grey matter substance in the left insula and left trigonal frontal gyrus. Judging from our findings, an abnormal frontal cortex, particularly left sided insula, frontal opercular, trigonal frontal gyrus and orbital frontal would make PD patients vulnerable to hallucinations. Compromise of the left operculum distinguished cases with VHs and cognitive dysfunction. Our findings reinforce the theoretical concept of a top-down visual processing in the genesis of VHs in PD.

  10. Design characteristics of pediatric prosthetic knees.

    Science.gov (United States)

    Andrysek, Jan; Naumann, Stephen; Cleghorn, William L

    2004-12-01

    We examined whether pediatric prosthetic single-axis knees can theoretically provide the beneficial functional characteristics of polycentric knees and the design considerations needed to realize this. Five children and their parents provided subjective opinions of the relative importance of functional requirements (FRs) for the knee. FRs related to comfort, fatigue, stability, and falling were found to be of high importance, while sitting appearance and adequate knee flexion were of lower importance. Relationships were drawn between these FRs and deductions were made regarding the importance of associated design parameters. Stance-phase control was rated to be of greatest importance followed by toe clearance. Models were developed for five knees including four- and six-bar knees, corresponding to two commercially available components, and for three configurations of a single-axis knee. Stance-phase control, specifically stability after heel-strike and swing-phase initiation at push-off, and toe clearance were simulated. The results suggest that a single-axis knee design incorporating stance-phase control will mutually satisfy the identified set of highly and moderately important FRs. PMID:15614992

  11. Prototyping Cognitive Prosthetics for People with Dementia

    Science.gov (United States)

    Davies, Richard; Nugent, Chris D.; Donnelly, Mark

    In the COGKNOW project, a cognitive prosthetic has been developed through the application of Information and Communication Technology (ICT)-based services to address the unmet needs and demands of persons with dementia. The primary aim of the developed solution was to offer guidance with conducting everyday activities for persons with dementia. To encourage a user-centred design process, a three-phased methodology was introduced to facilitate cyclical prototype development. At each phase, user input was used to guide the future development. As a prerequisite to the first phase of development, user requirements were gathered to identify a small set of functional requirements from which a number of services were identified. Following implementation of these initial services, the prototype was evaluated on a cohort of users and, through observing their experiences and recording their feedback, the design was refined and the prototype redeveloped to include a number of additional services in the second phase. The current chapter provides an overview of the services designed and developed in the first two phases.

  12. Prosthetic rehabilitation of the upper limb amputee

    Directory of Open Access Journals (Sweden)

    Bernard O′Keeffe

    2011-01-01

    Full Text Available The loss of all or part of the arm is a catastrophic event for a patient and a significant challenge to rehabilitation professionals and prosthetic engineers. The large, upper extremity amputee population in India has, historically, been poorly served, with most having no access to support or being provided with ineffective prostheses. In recent years, the arrival of organisations like Otto Bock has made high quality service standards and devices accessible to more amputees. This review attempts to provide surgeons and other medical professionals with an overview of the multidisciplinary, multistage rehabilitation process and the solution options available. With worldwide upper extremity prosthesis rejection rates at significant levels, the review also describes some of the factors which influence the outcome. This is particularly relevant in the Indian context where the service can involve high cost investments. It is the responsibility of all contributing professionals to guide vulnerable patients through the process and try to maximise the benefit that can be obtained within the resources available.

  13. Toxicology of antimicrobial nanoparticles for prosthetic devices

    Science.gov (United States)

    Nuñez-Anita, Rosa Elvira; Acosta-Torres, Laura Susana; Vilar-Pineda, Jorge; Martínez-Espinosa, Juan Carlos; de la Fuente-Hernández, Javier; Castaño, Víctor Manuel

    2014-01-01

    Advances in nanotechnology are producing an accelerated proliferation of new nanomaterial composites that are likely to become an important source of engineered health-related products. Nanoparticles with antifungal effects are of great interest in the formulation of microbicidal materials. Fungi are found as innocuous commensals and colonize various habitats in and on humans, especially the skin and mucosa. As growth on surfaces is a natural part of the Candida spp. lifestyle, one can expect that Candida organisms colonize prosthetic devices, such as dentures. Macromolecular systems, due to their properties, allow efficient use of these materials in various fields, including the creation of reinforced nanoparticle polymers with antimicrobial activity. This review briefly summarizes the results of studies conducted during the past decade and especially in the last few years focused on the toxicity of different antimicrobial polymers and factors influencing their activities, as well as the main applications of antimicrobial polymers in dentistry. The present study addresses aspects that are often overlooked in nanotoxicology studies, such as careful time-dependent characterization of agglomeration and ion release. PMID:25187703

  14. Peri-prosthetic fracture vibration testing

    Energy Technology Data Exchange (ETDEWEB)

    Cruce, Jesse R [Los Alamos National Laboratory; Erwin, Jenny R [Los Alamos National Laboratory; Remick, Kevin R [Los Alamos National Laboratory; Cornwell, Phillip J [Los Alamos National Laboratory; Menegini, R. Michael [INDIANA UNIV.; Racanelli, Joe [STRYKER ORTHOPARDICS

    2010-11-08

    The purpose of this study was to establish a test setup and vibration analysis method to predict femoral stem seating and prevent bone fracture using accelerometer and force response data from an instrumented stem and impactor. This study builds upon earlier studies to identify a means to supplement a surgeon's tactile and auditory senses by using damage identification techniques normally used for civil and mechanical structures. Testing was conducted using foam cortical shell sawbones prepared for stems of different geometries. Each stem was instrumented with an accelerometer. Two impactor designs were compared: a monolithic impactor and a two-piece impactor, each with an integrated load cell and accelerometer. Acceleration and force measurements were taken in the direction of impaction. Comparisons between different methods of applying an impacting force were made, including a drop tower and a surgical hammer. The effect of varying compliance on the data was also investigated. The ultimate goal of this study was to assist in the design of an integrated portable data acquisition system capable of being used in future cadaveric testing. This paper will discuss the experimental setup and the subsequent results of the comparisons made between impactors, prosthetic geometries, compliances, and impact methods. The results of this study can be used for both future replicate testing as well as in a cadaveric environment.

  15. Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation

    DEFF Research Database (Denmark)

    Wallentin, Mikkel; Skakkebæk, Anne; Bojesen, Anders;

    2016-01-01

    Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS...... relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS=49; Controls=49) responded to whether the words “GREEN” or “RED” were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often...... with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain’s motor network with no difference between groups...

  16. Developing an online steady-state visual evoked potential-based brain-computer interface system using EarEEG.

    Science.gov (United States)

    Wang, Yu-Te; Nakanishi, Masaki; Kappel, Simon Lind; Kidmose, Preben; Mandic, Danilo P; Wang, Yijun; Cheng, Chung-Kuan; Jung, Tzyy-Ping

    2015-01-01

    The purpose of this study is to demonstrate an online steady-state visual evoked potential (SSVEP)-based BCI system using EarEEG. EarEEG is a novel recording concept where electrodes are embedded on the surface of earpieces customized to the individual anatomical shape of users' ear. It has been shown that the EarEEG can be used to record SSVEPs in previous studies. However, a long distance between the visual cortex and the ear makes the signal-to-noise ratio (SNR) of SSVEPs acquired by the EarEEG relatively low. Recently, filter bank- and training data-based canonical correlation analysis algorithms have shown significant performance improvement in terms of accuracy of target detection and information transfer rate (ITR). This study implemented an online four-class SSVEP-based BCI system using EarEEG. Four subjects participated in offline and online BCI experiments. For the offline classification, an average accuracy of 82.71±11.83 % was obtained using 4 sec-long SSVEPs acquired from earpieces. In the online experiment, all subjects successfully completed the tasks with an average accuracy of 87.92±12.10 %, leading to an average ITR of 16.60±6.55 bits/min. The results suggest that EarEEG can be used to perform practical BCI applications. The EarEEG has the potential to be used as a portable EEG recordings platform, that could enable real-world BCI applications. PMID:26736745

  17. Distribution of serotonin and FMRF-amide in the brain of Lymnaea stagnalis with respect to the visual system

    Institute of Scientific and Technical Information of China (English)

    Oksana P.TUCHINA; Valery V.ZHUKOV; Victor B.MEYER-ROCHOW

    2012-01-01

    Despite serotonin's and FMRF-amide's wide distribution in the nervous system of invertebrates and their importance as neurotransmitters,the exact roles they play in neuronal networks leaves many questions.We mapped the presence of serotonin and FMRF-amide-immunoreactivity in the central nervous system and eyes of the pond snail Lymnaea stagnalis and interpreted the results in connection with our earlier findings on the central projections of different peripheral nerves.Since the chemical nature of the intercellular connections in the retina of L.stagnalis is still largely unknown,we paid special attention to clarifying the role of serotonin and FMRF-amide in the visual system of this snail and compared our findings with those reported from other species.At least one serotonin- and one FMRF-amidergic fibre were labeled in each optic nerve,and since no cell bodies in the eye showed immunoreactivity to these neurotransmitters,we believe that efferent fibres with somata located in the central ganglia branch at the base of the eye and probably release 5HT and FMRF-amide as neuro-hormones.Double labelling revealed retrograde transport of neurobiotin through the optic nerve,allowing us to conclude that the central pathways and serotonin- and FMRF-amide-immunoreactive cells and fibres have different locations in the CNS in L.stagnalis.The chemical nature of the fibres,which connect the two eyes in L.stagnalis,is neither serotoninergic nor FMRF-amidergic.

  18. Recent advancements in prosthetic hand technology.

    Science.gov (United States)

    Saikia, Angana; Mazumdar, Sushmi; Sahai, Nitin; Paul, Sudip; Bhatia, Dinesh; Verma, Suresh; Rohilla, Punit Kumar

    2016-07-01

    Recently, significant advances over the past decade have been made in robotics, artificial intelligence and other cognitive related fields, allowing development of highly sophisticated bio-mimetic robotics systems. In addition, enormous number of robots have been designed and assembled by explicitly realising their biological oriented behaviours. To enhance skill behaviours and adequate grasping abilities in these devices, a new phase of dexterous hands has been developed recently with bio-mimetically oriented and bio-inspired functionalities. The aim in writing this review paper is to present a detailed insight towards the development of the bio-mimetic based dexterous robotic multi-fingered artificial hand. An "ideal" upper limb prosthesis should be perceived as a part of their natural body by the amputee and should replicate sensory-motor capabilities of the amputated limb. Upper-limb amputations are most often the result of sudden trauma to the body, although they also can be caused by malignancy, congenital deficiencies and vascular diseases. This paper discusses the different bio-mimetic approaches using a framework that permits for a common description of biological and technical based hand manipulation behaviour. In particular, the review focuses on a number of developments in the inspired robotic systems. In conclusion, the study found that a huge amount of research efforts in terms of kinematics, dynamics, modelling and control methodologies are being put in to improve the present hand technology, thereby providing more functionality to the prosthetic limb of the amputee. This would improve their quality-of-life and help in performing activities of daily living (ADL) tasks with comparative ease in the near future. PMID:27098838

  19. Consumer satisfaction in prosthetics and orthotics facilities.

    Science.gov (United States)

    Geertzen, J H B; Gankema, H G J; Groothoff, J W; Dijkstra, P U

    2002-04-01

    The aim of this study was to assess consumer/patient satisfaction with the services of the prosthetics and orthotics (P&O) facilities in the north of the Netherlands, using a modified SERVQUAL questionnaire. In this questionnaire, consumer interests and experiences are assessed on a 5-point Likert scale. The questionnaire consisted of 30 items covering 5 domains: tangibles, reliability, responsiveness, assurance and empathy and the consumers were invited to give an overall rating of satisfaction (scale 1-10). Consumers of four P&O facilities were asked to participate. In total 496 consumers (aged 0-76) participated; 279 consumers received orthopaedic shoes and 217 consumers received either prostheses or orthoses. An overall satisfaction rating of 8 or higher was given by 75% of the consumers (mean 8.0; sd=1.2). Consumers were defined as satisfied with the services of the P&O facility if they rated their experiences on a certain item equal or better than their rating of its importance. Eighty-five percent (85%) or more of the consumers were satisfied with the P&O facility in 24 of the 30 (80%) items of the SERVQUAL questionnaire. Of the 6 less unsatisfying items, 3 were related to the domain "tangibles", 2 were related to the domain "empathy" and 1 to the domain "responsiveness". The management of the P&O facility can use this information to increase consumer satisfaction by improving quality and service at these items. In general, the degree of consumer overall satisfaction was not related to age, gender, and type of assistive device or "length of relationship of consumer" and P&O facility. Only consumers who received orthopaedic shoes rated their overall satisfaction significantly lower (0.3) than consumers who received other types of devices. This difference is clinically not relevant. PMID:12043928

  20. Consumer satisfaction in prosthetics and orthotics facilities.

    Science.gov (United States)

    Geertzen, J H B; Gankema, H G J; Groothoff, J W; Dijkstra, P U

    2002-04-01

    The aim of this study was to assess consumer/patient satisfaction with the services of the prosthetics and orthotics (P&O) facilities in the north of the Netherlands, using a modified SERVQUAL questionnaire. In this questionnaire, consumer interests and experiences are assessed on a 5-point Likert scale. The questionnaire consisted of 30 items covering 5 domains: tangibles, reliability, responsiveness, assurance and empathy and the consumers were invited to give an overall rating of satisfaction (scale 1-10). Consumers of four P&O facilities were asked to participate. In total 496 consumers (aged 0-76) participated; 279 consumers received orthopaedic shoes and 217 consumers received either prostheses or orthoses. An overall satisfaction rating of 8 or higher was given by 75% of the consumers (mean 8.0; sd=1.2). Consumers were defined as satisfied with the services of the P&O facility if they rated their experiences on a certain item equal or better than their rating of its importance. Eighty-five percent (85%) or more of the consumers were satisfied with the P&O facility in 24 of the 30 (80%) items of the SERVQUAL questionnaire. Of the 6 less unsatisfying items, 3 were related to the domain "tangibles", 2 were related to the domain "empathy" and 1 to the domain "responsiveness". The management of the P&O facility can use this information to increase consumer satisfaction by improving quality and service at these items. In general, the degree of consumer overall satisfaction was not related to age, gender, and type of assistive device or "length of relationship of consumer" and P&O facility. Only consumers who received orthopaedic shoes rated their overall satisfaction significantly lower (0.3) than consumers who received other types of devices. This difference is clinically not relevant.

  1. Methods for characterization of mechanical and electrical prosthetic vacuum pumps

    Directory of Open Access Journals (Sweden)

    Oluseeni Komolafe, PhD

    2013-11-01

    Full Text Available Despite increasingly widespread adoption of vacuum-assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians’ choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio] and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock] prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3 to 197 cm3 (12 in.3 were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg. The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.

  2. Methods for characterization of mechanical and electrical prosthetic vacuum pumps.

    Science.gov (United States)

    Komolafe, Oluseeni; Wood, Sean; Caldwell, Ryan; Hansen, Andrew; Fatone, Stefania

    2013-01-01

    Despite increasingly widespread adoption of vacuum-assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm(3) (2 in.(3)) to 197 cm(3) (12 in.(3)) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.

  3. Biomechanical design considerations for transradial prosthetic interface: A review.

    Science.gov (United States)

    Sang, Yuanjun; Li, Xiang; Luo, Yun

    2016-03-01

    Traditional function and comfort assessment of transradial prostheses pay scant attention to prosthetic interface. With better understanding of the biomechanics of prosthetic interface comes better efficiency and safety for interface design; in this way, amputees are more likely to accept prosthetic usage. This review attempts to provide design and selection criteria of transradial interface for prosthetists and clinicians. Various transradial socket types in the literature were chronologically reviewed. Biomechanical discussion of transradial prosthetic interface design from an engineering point of view was also done. Suspension control, range of motion, stability, as well as comfort and safety of socket designs have been considered in varying degrees in the literature. The human-machine interface design should change from traditional "socket design" to new "interface design." From anatomy and physiology to biomechanics of the transradial residual limb, the force and motion transfer, together with comfort and safety, are the two main aspects in prosthetic interface design. Load distribution and transmission should mainly rely on achieving additional skeletal control through targeted soft tissue relief. Biomechanics of the residual limb soft tissues should be studied to find the relationship between mechanical properties and the comfort and safety of soft tissues.

  4. Prosthetic alignment effects on gait symmetry: a case study.

    Science.gov (United States)

    Andres, R O; Stimmel, S K

    1990-05-01

    The loss of a significant portion of a lower extremity causes changes in the usual pattern of human ambulation. These changes have been documented kinematically, kinetically and metabolically, giving insight into the costs of limb amputation relative to ambulatory efforts. The role of the prosthetist is to provide a limb substitute to achieve the best gait performance, while assuring maximum comfort for the patient. This case study examined the effects of antero-posterior alignment of a below-knee prosthesis on sagittal plane gait kinematics by comparing the anatomical side with the prosthetic side. The greatest changes due to variations of alignment were found during the prosthetic stance phase; knee angles showed the greatest asymmetry between anatomical and prosthetic sides. The stance phase on the prosthetic side was reduced with anterior socket displacement due to early knee flexion and toe-off. Posterior socket displacement caused a greater maximum centre of gravity height, but anterior socket displacement caused greater knee flexion which decreased the maximum centre of gravity height. Asymmetries in temporal and other kinematic parameters were not always minimal at the optimal alignment subjectively selected by a certified prosthetist. Comparisons of asymmetry ratios with prosthetic side data revealed the subclinical sensitivity of this amputee to antero-posterior alignment discrepancies.

  5. Design, Sensing and Control of a Robotic Prosthetic Eye for Natural Eye Movement

    Directory of Open Access Journals (Sweden)

    J. J. Gu

    2006-01-01

    Full Text Available Loss of an eye is a tragedy for a person, who may suffer psychologically and physically. This paper is concerned with the design, sensing and control of a robotic prosthetic eye that moves horizontally in synchronization with the movement of the natural eye. Two generations of robotic prosthetic eye models have been developed. The first generation model uses an external infrared sensor array mounted on the frame of a pair of eyeglasses to detect the natural eye movement and to feed the control system to drive the artificial eye to move with the natural eye. The second generation model removes the impractical usage of the eye glass frame and uses the human brain EOG (electro-ocular-graph signal picked up by electrodes placed on the sides of a person's temple to carry out the same eye movement detection and control tasks as mentioned above. Theoretical issues on sensor failure detection and recovery, and signal processing techniques used in sensor data fusion, are studied using statistical methods and artificial neural network based techniques. In addition, practical control system design and implementation using micro-controllers are studied and implemented to carry out the natural eye movement detection and artificial robotic eye control tasks. Simulation and experimental studies are performed, and the results are included to demonstrate the effectiveness of the research project reported in this paper.

  6. A comparison of two spelling Brain-Computer Interfaces based on visual P3 and SSVEP in Locked-In Syndrome.

    Directory of Open Access Journals (Sweden)

    Adrien Combaz

    Full Text Available OBJECTIVES: We study the applicability of a visual P3-based and a Steady State Visually Evoked Potentials (SSVEP-based Brain-Computer Interfaces (BCIs for mental text spelling on a cohort of patients with incomplete Locked-In Syndrome (LIS. METHODS: Seven patients performed repeated sessions with each BCI. We assessed BCI performance, mental workload and overall satisfaction for both systems. We also investigated the effect of the quality of life and level of motor impairment on the performance. RESULTS: All seven patients were able to achieve an accuracy of 70% or more with the SSVEP-based BCI, compared to 3 patients with the P3-based BCI, showing a better performance with the SSVEP BCI than with the P3 BCI in the studied cohort. Moreover, the better performance of the SSVEP-based BCI was accompanied by a lower mental workload and a higher overall satisfaction. No relationship was found between BCI performance and level of motor impairment or quality of life. CONCLUSION: Our results show a better usability of the SSVEP-based BCI than the P3-based one for the sessions performed by the tested population of locked-in patients with respect to all the criteria considered. The study shows the advantage of developing alternative BCIs with respect to the traditional matrix-based P3 speller using different designs and signal modalities such as SSVEPs to build a faster, more accurate, less mentally demanding and more satisfying BCI by testing both types of BCIs on a convenience sample of LIS patients.

  7. Prosthetic hand sensor placement: Analysis of touch perception during the grasp

    Directory of Open Access Journals (Sweden)

    Mirković Bojana

    2014-01-01

    Full Text Available Humans rely on their hands to perform everyday tasks. The hand is used as a tool, but also as the interface to “sense” the world. Current prosthetic hands are based on sophisticated multi-fingered structures, and include many sensors which counterpart natural proprioceptors and exteroceptors. The sensory information is used for control, but not sent to the user of the hand (amputee. Grasping without sensing is not good enough. This research is part of the development of the sensing interface for amputees, specifically addressing the analysis of human perception while grasping. The goal is to determine the small number of preferred positions of sensors on the prosthetic hand. This task has previously been approached by trying to replicate a natural sensory system characteristic for healthy humans, resulting in a multitude of redundant sensors and basic inability to make the patient aware of the sensor readings on the subconscious level. We based our artificial perception system on the reported sensations of humans when grasping various objects without seeing the objects (obstructed visual feedback. Subjects, with no known sensory deficits, were asked to report on the touch sensation while grasping. The analysis included objects of various sizes, weights, textures and temperatures. Based on this data we formed a map of the preferred positions for the sensors that is appropriate for five finger human-like robotic hand. The final map was intentionally minimized in size (number of sensors.

  8. Possibility of magnetic resonance imaging application in teaching preclinical dentistry - endodontic and prosthetic treatment prognosis

    International Nuclear Information System (INIS)

    that has been achieved, indicate at the possibility of employing techniques of the MRI, that are based on the 3D sequence of the Spin Echo as well as on the Single Point Imaging, for the dimensional mapping of the outer topography of teeth as well as a structure of the root canals for the therapeutic and didactical purposes. A numerical model of prepared root canals obtained with the method of the magnetic resonance visualization may constitute in the future a basis for a non-impressional technique of imaging, useful for reconstructive dentistry and for teaching preclinical dentistry in endodontic and prosthetic speciality. (author)

  9. Surgical-prosthetic treatment of large mandibular cysts

    Directory of Open Access Journals (Sweden)

    Džambas Ljubiša D.

    2003-01-01

    Full Text Available This paper presents a combined surgical-prosthetic procedure of reconstructing mandibular bone defect in a 53 year old patient, following enucleation of a mandibular cyst (Cystectomy Partsch II. After a thorough diagnostic evaluation, a surgical procedure was planned with the particular attention to the nature of the disease, patient’s condition, size and extension of the cyst, tissue loss, and the possibilities of prosthetic management of a mandibular bone defect with partial postresection dental prosthesis. It is of great importance to point to the significance of teamwork of a maxillofacial surgeon and a specialist in prosthodontics. This kind of cooperation provided very effective and less risky soft tissue, as well as bone tissue regeneration (osteogenesis. The patient’s recovery was fast, and he could return to his daily activities and work without significant changes regarding quality of life after surgery and prosthetic treatment.

  10. Uncemented allograft-prosthetic composite reconstruction of the proximal femur

    Directory of Open Access Journals (Sweden)

    Li Min

    2014-01-01

    Full Text Available Background: Allograft-prosthetic composite can be divided into three groups names cemented, uncemented, and partially cemented. Previous studies have mainly reported outcomes in cemented and partially cemented allograft-prosthetic composites, but have rarely focused on the uncemented allograft-prosthetic composites. The objectives of our study were to describe a surgical technique for using proximal femoral uncemented allograft-prosthetic composite and to present the radiographic and clinical results. Materials and Methods: Twelve patients who underwent uncemented allograft-prosthetic composite reconstruction of the proximal femur after bone tumor resection were retrospectively evaluated at an average followup of 24.0 months. Clinical records and radiographs were evaluated. Results: In our series, union occurred in all the patients (100%; range 5-9 months. Until the most recent followup, there were no cases with infection, nonunion of the greater trochanter, junctional bone resorption, dislocation, allergic reaction, wear of acetabulum socket, recurrence, and metastasis. But there were three periprosthetic fractures which were fixed using cerclage wire during surgery. Five cases had bone resorption in and around the greater trochanter. The average Musculoskeletal Tumor Society (MSTS score and Harris hip score (HHS were 26.2 points (range 24-29 points and 80.6 points (range 66.2-92.7 points, respectively. Conclusions: These results showed that uncemented allograft-prosthetic composite could promote bone union through compression at the host-allograft junction and is a good choice for proximal femoral resection. Although this technology has its own merits, long term outcomes are yet not validated.

  11. Changes of the directional brain networks related with brain plasticity in patients with long-term unilateral sensorineural hearing loss.

    Science.gov (United States)

    Zhang, G-Y; Yang, M; Liu, B; Huang, Z-C; Li, J; Chen, J-Y; Chen, H; Zhang, P-P; Liu, L-J; Wang, J; Teng, G-J

    2016-01-28

    Previous studies often report that early auditory deprivation or congenital deafness contributes to cross-modal reorganization in the auditory-deprived cortex, and this cross-modal reorganization limits clinical benefit from cochlear prosthetics. However, there are inconsistencies among study results on cortical reorganization in those subjects with long-term unilateral sensorineural hearing loss (USNHL). It is also unclear whether there exists a similar cross-modal plasticity of the auditory cortex for acquired monaural deafness and early or congenital deafness. To address this issue, we constructed the directional brain functional networks based on entropy connectivity of resting-state functional MRI and researched changes of the networks. Thirty-four long-term USNHL individuals and seventeen normally hearing individuals participated in the test, and all USNHL patients had acquired deafness. We found that certain brain regions of the sensorimotor and visual networks presented enhanced synchronous output entropy connectivity with the left primary auditory cortex in the left long-term USNHL individuals as compared with normally hearing individuals. Especially, the left USNHL showed more significant changes of entropy connectivity than the right USNHL. No significant plastic changes were observed in the right USNHL. Our results indicate that the left primary auditory cortex (non-auditory-deprived cortex) in patients with left USNHL has been reorganized by visual and sensorimotor modalities through cross-modal plasticity. Furthermore, the cross-modal reorganization also alters the directional brain functional networks. The auditory deprivation from the left or right side generates different influences on the human brain. PMID:26621123

  12. Toxicology of antimicrobial nanoparticlesfor prosthetic devices

    Directory of Open Access Journals (Sweden)

    Nuñez-Anita RE

    2014-08-01

    Full Text Available Rosa Elvira Nuñez-Anita,1 Laura Susana Acosta-Torres,2 Jorge Vilar-Pineda,2 Juan Carlos Martínez-Espinosa,3 Javier de la Fuente-Hernández, 2 Víctor Manuel Castaño4 1Facultad de Medicina Veterinariay Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarìmbaro Municipio de Morelia, Michoacán, México; 2Escuela Nacionalde Estudios Superiores, Universidad Nacional Autónoma de México, Unidad León, Leòn Guanajuato, México; 3Unidad Profesional Interdisciplinaria de Ingenieria Campus Guanajuato, Instituto Politécnico Nacional, Leòn Guanajuato, México; 4Departamento de Materiales Moleculares, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Querètaro, México Abstract: Advances in nanotechnology are producing an accelerated proliferation of new nanomaterial composites that are likely to become an important source of engineered health-related products. Nanoparticles with antifungal effects are of great interest in the formulation of microbicidal materials. Fungi are found as innocuous commensals and colonize various habitats in and on humans, especially the skin and mucosa. As growth on surfaces is a natural part of the Candida spp. lifestyle, one can expect that Candida organisms colonize prosthetic devices, such as dentures. Macromolecular systems, due to their properties, allow efficient use of these materials in various fields, including the creation of reinforced nanoparticle polymers with antimicrobial activity. This review briefly summarizes the results of studies conducted during the past decade and especially in the last few years focused on the toxicity of different antimicrobial polymers and factors influencing their activities, as well as the main applications of antimicrobial polymers in dentistry. The present study addresses aspects that are often overlooked in nanotoxicology studies, such as careful time-dependent characterization of agglomeration

  13. “Optical communication with brain cells by means of an implanted duplex micro-device with optogenetics and Ca2+ fluoroimaging”

    Science.gov (United States)

    Kobayashi, Takuma; Haruta, Makito; Sasagawa, Kiyotaka; Matsumata, Miho; Eizumi, Kawori; Kitsumoto, Chikara; Motoyama, Mayumi; Maezawa, Yasuyo; Ohta, Yasumi; Noda, Toshihiko; Tokuda, Takashi; Ishikawa, Yasuyuki; Ohta, Jun

    2016-02-01

    To better understand the brain function based on neural activity, a minimally invasive analysis technology in a freely moving animal is necessary. Such technology would provide new knowledge in neuroscience and contribute to regenerative medical techniques and prosthetics care. An application that combines optogenetics for voluntarily stimulating nerves, imaging to visualize neural activity, and a wearable micro-instrument for implantation into the brain could meet the abovementioned demand. To this end, a micro-device that can be applied to the brain less invasively and a system for controlling the device has been newly developed in this study. Since the novel implantable device has dual LEDs and a CMOS image sensor, photostimulation and fluorescence imaging can be performed simultaneously. The device enables bidirectional communication with the brain by means of light. In the present study, the device was evaluated in an in vitro experiment using a new on-chip 3D neuroculture with an extracellular matrix gel and an in vivo experiment involving regenerative medical transplantation and gene delivery to the brain by using both photosensitive channel and fluorescent Ca2+ indicator. The device succeeded in activating cells locally by selective photostimulation, and the physiological Ca2+ dynamics of neural cells were visualized simultaneously by fluorescence imaging.

  14. Reconsidering evidence-based practice in prosthetic rehabilitation : a shared enterprise

    NARCIS (Netherlands)

    van Twillert, S.; Geertzen, J.; Hemminga, T.; Postema, K.; Lettinga, A.

    2013-01-01

    Background: A divide is experienced between producers and users of evidence in prosthetic rehabilitation. Objective: To discuss the complexity inherent in establishing evidence-based practice in a prosthetic rehabilitation team illustrated by the case of prosthetic prescription for elderly dysvascul

  15. Patient-Specific Prosthetic Fingers by Remote Collaboration - A Case Study

    CERN Document Server

    Cabibihan, John-John

    2011-01-01

    The concealment of amputation through prosthesis usage can shield an amputee from social stigma and help improve the emotional healing process especially at the early stages of hand or finger loss. However, the traditional techniques in prosthesis fabrication defy this as the patients need numerous visits to the clinics for measurements, fitting and follow-ups. This paper presents a method for constructing a prosthetic finger through online collaboration with the designer. The main input from the amputee comes from the Computer Tomography (CT) data in the region of the affected and the non-affected fingers. These data are sent over the internet and the prosthesis is constructed using visualization, computer-aided design and manufacturing tools. The finished product is then shipped to the patient. A case study with a single patient having an amputated ring finger at the proximal interphalangeal joint shows that the proposed method has a potential to address the patient's psychosocial concerns and minimize the ...

  16. Music Alters Visual Perception

    NARCIS (Netherlands)

    Jolij, Jacob; Meurs, Maaike

    2011-01-01

    Background: Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e. g., memory) and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the pe

  17. Dental prosthetic status and prosthetic needs of institutionalised elderly population in oldage homes of jabalpur city, madhya pradesh, India.

    Science.gov (United States)

    Deogade, Suryakant C; Vinay, S; Naidu, Sonal

    2013-12-01

    Oral disorders are cumulative throughout life and hence unfavourable outcomes are likely to be greatest among the elderly. A descriptive cross-sectional study was conducted among institutionalized geriatric population in old-age homes of Jabalpur city, Madhya Pradesh, to assess their prosthetic status and prosthetic needs. A cross-sectional survey was conducted in all the four old-age homes of Jabalpur city, Madhya Pradesh state, India. All residents aged 60 years and above formed the study population. The recording of prosthetic status and prosthetic needs was carried out according to the World Health Organisation (WHO) Oral Health Assessment Form (1997). A total of 224 individuals were included in the study of which 123 were females and 101 were males. Seventy five percent of the females and 55 % of the males had no prostheses in their upper arch and 61 % of the females and 76 % of the males had no prostheses in their lower arch. More number of males presented with 'Bridges' in their upper arch when compared to females (P value = 0.006). Highest prosthetic need in males was multi-unit prosthesis (42 % in upper arch and 41 % in lower arch) whereas, females' required full prosthesis (39 % in both the upper arch and lower arches). Ageing presents some formidable challenges, particularly with the institutionalised. This study clearly demonstrates a high insufficiency of prosthetic care among the institutionalized elderly population. Any preparation towards the provision of oral health care should not be limited to treatment alone but, more importantly focus on empowering this elderly community with information and education programmes. PMID:24431796

  18. Dental prosthetic status and prosthetic needs of institutionalised elderly population in oldage homes of jabalpur city, madhya pradesh, India.

    Science.gov (United States)

    Deogade, Suryakant C; Vinay, S; Naidu, Sonal

    2013-12-01

    Oral disorders are cumulative throughout life and hence unfavourable outcomes are likely to be greatest among the elderly. A descriptive cross-sectional study was conducted among institutionalized geriatric population in old-age homes of Jabalpur city, Madhya Pradesh, to assess their prosthetic status and prosthetic needs. A cross-sectional survey was conducted in all the four old-age homes of Jabalpur city, Madhya Pradesh state, India. All residents aged 60 years and above formed the study population. The recording of prosthetic status and prosthetic needs was carried out according to the World Health Organisation (WHO) Oral Health Assessment Form (1997). A total of 224 individuals were included in the study of which 123 were females and 101 were males. Seventy five percent of the females and 55 % of the males had no prostheses in their upper arch and 61 % of the females and 76 % of the males had no prostheses in their lower arch. More number of males presented with 'Bridges' in their upper arch when compared to females (P value = 0.006). Highest prosthetic need in males was multi-unit prosthesis (42 % in upper arch and 41 % in lower arch) whereas, females' required full prosthesis (39 % in both the upper arch and lower arches). Ageing presents some formidable challenges, particularly with the institutionalised. This study clearly demonstrates a high insufficiency of prosthetic care among the institutionalized elderly population. Any preparation towards the provision of oral health care should not be limited to treatment alone but, more importantly focus on empowering this elderly community with information and education programmes.

  19. Determining asymmetry of roll-over shapes in prosthetic walking

    NARCIS (Netherlands)

    Curtze, C.; Otten, B.; Hof, A.L.; Postema, K.

    2011-01-01

    How does the inherent asymmetry of the locomotor system in people with lower-limb amputation affect the ankle-foot roll-over shape of prosthetic walking? In a single-case design, we evaluated the walking patterns of six people with lower-limb amputation (3 transtibial and 3 transfemoral) and three m

  20. PROSTHETIC GAIT OF UNILATERAL TRANSFEMORAL AMPUTEES - A KINEMATIC STUDY

    NARCIS (Netherlands)

    JAEGERS, SMHJ; ARENDZEN, JH; DEJONGH, HJ

    1995-01-01

    Objective: The prosthetic gait of unilateral transfemoral amputees. Design: Case series. Setting: Laboratory of Gait Analysis (GIGA-system of K-lab) in the Department of Rehabilitation of a university hospital. Patients: Eleven men with transfemoral amputation (mean age 35.7 years) participated. The

  1. Prosthetic Hand For Holding Rods, Tools, And Handles

    Science.gov (United States)

    Belcher, Jewell G., Jr.; Vest, Thomas W.

    1995-01-01

    Prosthetic hand with quick-grip/quick-release lever broadens range of specialized functions available to lower-arm amputee by providing improved capabilities for gripping rods, tools, handles, and like. Includes two stationary lower fingers opposed by one pivoting upper finger. Lever operates in conjunction with attached bracket.

  2. Selective criteria for successful long-term prosthetic use.

    Science.gov (United States)

    Mueller, M J; Delitto, A

    1985-07-01

    The purpose of this study was to identify criteria contributing to successful long-term prosthetic use in patients with an amputation secondary to vascular disease. All elderly patients with a unilateral below-knee amputation or an above-knee amputation, secondary to vascular disease, seen in our clinic between 1977 and 1982 were included in this telephone survey. Of those contacted, 37 of 38 below-knee amputees (BKAs) and 7 of 18 above-knee amputees (AKAs) still wore their prostheses at least part of every day (success). We used a two-tailed chi-square to compare the success of the BKAs with the success of the AKAs. The BKAs were successful more often (X2 = 24.81, df = 1, p less than .001). All AKAs also were characterized according to age, time from prescription, obesity, ambulatory status, strength, range of motion, sex, general compliance, and medical problems after prosthetic prescription. Of these criteria, only compliance and medical problems after prescription showed a significant difference between successful and nonsuccessful long-term AKA prosthetic users (X2 = 5.76, df = 1, p less than .05 for each criterion). As the demands of quality assurance and diagnostic related groupings increase, these results can assist the physical therapy clinician in setting realistic goals for the geriatric amputee and help predict if the patient will be a successful prosthetic user.

  3. Development of a prototype over-actuated biomimetic prosthetic hand.

    Directory of Open Access Journals (Sweden)

    Matthew R Williams

    Full Text Available The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results.

  4. Effect of Modifying Prosthetic Socket Base Materials by Adding Nanodiamonds

    Directory of Open Access Journals (Sweden)

    Lifang Ma

    2015-01-01

    Full Text Available The curing process of prosthetic socket base materials requires attention owing to a series of associated problems that are yet to be addressed and solved. However, to date, few relevant studies have been reported. In this paper, nanodiamonds modified with a silane coupling agent were dispersed into a prosthetic socket base material, and the performance of the modified base materials was investigated. Adding a predetermined amount of nanodiamonds to the prosthetic socket base material increased the glass transition temperature, improved the mechanical properties of the cured base material, and reduced the influence of the volatile gas formed during the curing process on the environment. With increasing nanodiamond contents, the glass transition temperature increased and the mechanical properties improved slightly. Owing to the high thermal conductivity of the nanodiamonds, the localized heat, as a result of the curing process, could be dissipated and released. Thus, adding nanodiamonds led to a more uniform temperature field forming in the curing system. This improved the curing process and reduced the formation of volatile monomers, thereby decreasing the adverse impact of the generated volatile gases on the environment. All of these provide a potential strategy for modifying prosthetic socket base materials.

  5. Consumer satisfaction with the services of prosthetics and orthotics facilities

    NARCIS (Netherlands)

    Bosmans, Joline; Geertzen, Jan; Dijkstra, Pieter U.

    2009-01-01

    Consumer satisfaction with the services provided in a prosthetics and orthotics (PO) facility has seldom been studied. The aim of this study was to analyze consumer satisfaction regarding the services provided by 15 PO facilities in The Netherlands. Consumers (n=1,364) of these PO facilities who wer

  6. 21 CFR 890.3025 - Prosthetic and orthotic accessory.

    Science.gov (United States)

    2010-04-01

    ... intended for medical purposes to support, protect, or aid in the use of a cast, orthosis (brace), or prosthesis. Examples of prosthetic and orthotic accessories include the following: A pelvic support band and belt, a cast shoe, a cast bandage, a limb cover, a prosthesis alignment device, a postsurgical pylon,...

  7. Early prosthetic valve endocarditis caused by Corynebacterium kroppenstedtii.

    Science.gov (United States)

    Hagemann, Jürgen Benjamin; Essig, Andreas; Herrmann, Manuel; Liebold, Andreas; Quader, Mohamed Abo

    2015-12-01

    Corynebacterium (C.) kroppenstedtii is a rarely detected agent of bacterial infections in humans. Here, we describe the first case of prosthetic valve endocarditis caused by C. kroppenstedtii. Application of molecular methods using surgically excised valve tissue was a cornerstone for the establishment of the microbiological diagnosis, which is crucial for targeted antimicrobial treatment.

  8. Case report of Streptomyces endocarditis of a prosthetic aortic valve.

    Science.gov (United States)

    Mossad, S B; Tomford, J W; Stewart, R; Ratliff, N B; Hall, G S

    1995-01-01

    We describe the first case of prosthetic valve endocarditis due to a Streptomyces sp. The patient presented with fever, cutaneous embolic lesions, and bacteremia 3 months after aortic valve replacement. Treatment required valve replacement and a long course of parenteral imipenem. PMID:8586732

  9. Case report of Streptomyces endocarditis of a prosthetic aortic valve.

    OpenAIRE

    Mossad, S B; Tomford, J W; Stewart, R; Ratliff, N B; Hall, G. S.

    1995-01-01

    We describe the first case of prosthetic valve endocarditis due to a Streptomyces sp. The patient presented with fever, cutaneous embolic lesions, and bacteremia 3 months after aortic valve replacement. Treatment required valve replacement and a long course of parenteral imipenem.

  10. Design and Implementation of Prosthetic Arm using Gear Motor Control Technique with Appropriate Testing

    CERN Document Server

    Neogi, Biswarup; Ghosal, Soumya; Das, Achintya; Tibarewala, D N

    2011-01-01

    Any part of the human body replication procedure commences the prosthetic control science. This paper highlights the hardware design technique of a prosthetic arm with implementation of gear motor control aspect. The prosthetic control arm movement has been demonstrated in this paper applying processor programming and with the successful testing of the designed prosthetic model. The architectural design of the prosthetic arm here has been replaced by lighter material instead of heavy metal, as well as the traditional EMG (electro myographic) signal has been replaced by the muscle strain.

  11. Nicotine effects on brain function during a visual oddball task: a comparison between conventional and EEG-informed fMRI analysis.

    Science.gov (United States)

    Warbrick, Tracy; Mobascher, Arian; Brinkmeyer, Jürgen; Musso, Francesco; Stoecker, Tony; Shah, N Jon; Fink, Gereon R; Winterer, Georg

    2012-08-01

    In a previous oddball task study, it was shown that the inclusion of electrophysiology (EEG), that is, single-trial P3 ERP parameters, in the analysis of fMRI responses can detect activation that is not apparent with conventional fMRI data modeling strategies [Warbrick, T., Mobascher, A., Brinkmeyer, J., Musso, F., Richter, N., Stoecker, T., et al. Single-trial P3 amplitude and latency informed event-related fMRI models yield different BOLD response patterns to a target detection task. Neuroimage, 47, 1532-1544, 2009]. Given that P3 is modulated by nicotine, including P3 parameters in the fMRI analysis might provide additional information about nicotine effects on brain function. A 1-mg nasal nicotine spray (0.5 mg each nostril) or placebo (pepper) spray was administered in a double-blind, placebo-controlled, within-subject, randomized, cross-over design. Simultaneous EEG-fMRI and behavioral data were recorded from 19 current smokers in response to an oddball-type visual choice RT task. Conventional general linear model analysis and single-trial P3 amplitude informed general linear model analysis of the fMRI data were performed. Comparing the nicotine with the placebo condition, reduced RTs in the nicotine condition were related to decreased BOLD responses in the conventional analysis encompassing the superior parietal lobule, the precuneus, and the lateral occipital cortex. On the other hand, reduced RTs were related to increased BOLD responses in the precentral and postcentral gyri, and ACC in the EEG-informed fMRI analysis. Our results show how integrated analyses of simultaneous EEG-fMRI data can be used to detect nicotine effects that would not have been revealed through conventional analysis of either measure in isolation. This emphasizes the significance of applying multimodal imaging methods to pharmacoimaging. PMID:22452559

  12. Autonomous control for mechanically stable navigation of microscale implants in brain tissue to record neural activity.

    Science.gov (United States)

    Anand, Sindhu; Kumar, Swathy Sampath; Muthuswamy, Jit

    2016-08-01

    Emerging neural prosthetics require precise positional tuning and stable interfaces with single neurons for optimal function over a lifetime. In this study, we report an autonomous control to precisely navigate microscale electrodes in soft, viscoelastic brain tissue without visual feedback. The autonomous control optimizes signal-to-noise ratio (SNR) of single neuronal recordings in viscoelastic brain tissue while maintaining quasi-static mechanical stress conditions to improve stability of the implant-tissue interface. Force-displacement curves from microelectrodes in in vivo rodent experiments are used to estimate viscoelastic parameters of the brain. Using a combination of computational models and experiments, we determined an optimal movement for the microelectrodes with bidirectional displacements of 3:2 ratio between forward and backward displacements and a inter-movement interval of 40 s for minimizing mechanical stress in the surrounding brain tissue. A regulator with the above optimal bidirectional motion for the microelectrodes in in vivo experiments resulted in significant reduction in the number of microelectrode movements (0.23 movements/min) and longer periods of stable SNR (53 % of the time) compared to a regulator using a conventional linear, unidirectional microelectrode movement (with 1.48 movements/min and stable SNR 23 % of the time). PMID:27457752

  13. Dutch evidence-based guidelines for amputation and prosthetics of the lower extremity : Rehabilitation process and prosthetics. Part 2

    NARCIS (Netherlands)

    Geertzen, Jan; van der Linde, Harmen; Rosenbrand, Kitty; Conradi, Marcel; Deckers, Jos; Koning, Jan; Rietman, Hans S.; van der Schaaf, Dick; van der Ploeg, Rein; Schapendonk, Johannes; Schrier, Ernst; Duijzentkunst, Rob Smit; Spruit-van Eijk, Monica; Versteegen, Gerbrig; Voesten, Harrie

    2015-01-01

    Background: A structured, multidisciplinary approach in the rehabilitation process after amputation is needed that includes a greater focus on the involvement of both (para)medics and prosthetists. There is considerable variation in prosthetic prescription concerning the moment of initial prosthesis

  14. Brain-Machine Interfaces: The Perception-Action Closed Loop

    OpenAIRE

    Millán, José del R.

    2015-01-01

    A brain-machine interface (BMI) is about transforming neural activity into action and sensation into perception (Figure 1). In a BMI system, neural signals recorded from the brain are fed into a decoding algorithm that translates these signals into motor outputs to control a variety of practical devices for motor-disabled people [1]-[5]. Feedback from the prosthetic device, conveyed to the user either via normal sensory pathways or directly through brain stimulation, establishes a closed cont...

  15. Brain Computer Interface-Controlling Devices Utilizing The Alpha Brain Waves

    OpenAIRE

    Rohan Hundia

    2015-01-01

    Abstract This paper describes the development and testing of an interface system whereby one can control external devices by voluntarily controlling alpha waves that is through eye movement. Such a system may be used for the control of prosthetics robotic arms and external devices like wheelchairs using the alpha brain waves and the Mu rhythm. The response generated through the movement of the eye detecting and controlling the amplitude of the alpha brain waves is interfaced and processed to...

  16. An illusionary prosthetic design for a unilateral cleft palate patient

    Directory of Open Access Journals (Sweden)

    Andaç Barkın Bavbek

    2014-01-01

    Full Text Available The prosthetic rehabilitation is an important part of the cleft lip and palate therapy assisting orthodontic and orthognathic treatments. Prosthesis does not only help to improve function and aesthetics but also needs to facilitate a better oral health. The aim of this report is to introduce the prosthetic approach of a 21-year-old female unilateral cleft palate patient that considered reinforcing the mobile canine adjacent to the cleft, easing the elimination of dental plaque from the remaining fistula and reaching an accurate occlusion. Facial aesthetics was established by the illusionary effect of a removable crown complex which is joined onto a fixed partial denture with a precision attachment system.

  17. Software tool for the prosthetic foot modeling and stiffness optimization.

    Science.gov (United States)

    Strbac, Matija; Popović, Dejan B

    2012-01-01

    We present the procedure for the optimization of the stiffness of the prosthetic foot. The procedure allows the selection of the elements of the foot and the materials used for the design. The procedure is based on the optimization where the cost function is the minimization of the difference between the knee joint torques of healthy walking and the walking with the transfemural prosthesis. We present a simulation environment that allows the user to interactively vary the foot geometry and track the changes in the knee torque that arise from these adjustments. The software allows the estimation of the optimal prosthetic foot elasticity and geometry. We show that altering model attributes such as the length of the elastic foot segment or its elasticity leads to significant changes in the estimated knee torque required for a given trajectory.

  18. [Effect of prosthesis cleansing agent on the prosthetic base fungi].

    Science.gov (United States)

    Temmer, K; Stipetić, D; Cekić-Arambasin, A; Kraljević, K

    1991-01-01

    Candida albicans and other fungi are frequently found in subjects wearing prostheses, especially in prostheses with poor hygiene, i.e. with accumulations of food, plaques and calculi. The aim of this study was to assess the efficacy of Corega extradent relative to fungi adhering to the prosthetic base. Results of the study showed the prosthesis hygiene to be substantially related to inflammation of palatal mucosa. The mean number of fungi per sq.cm of prosthetic base was 64 x 10(5). The number of fungi was redetermined after a two-day treatment with Corega extradent, with unchanged other habits of the prosthesis wearing and cleansing. The number of fungi decreased in all study subjects, the mean value of individual differences being 2238 times. In prostheses with a great number of fungi and extremely poor hygiene, the effect of Corega extradent was poorer, indicating the need of additional mechanical cleansing with a brush. PMID:1819938

  19. Terrain Identification for Prosthetic Knees Based on Electromyographic Signal Features

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The features of electromyographic (EMG) signals were investigated while people walking on different terrains, including up and down slopes, up and down stairs, and during level walking at different speeds. The features were used to develop a terrain identification method. The technology can be used to develop an intelligent transfemoral prosthetic limb with terrain identification capability. The EMG signals from 8 hip muscles of 13 healthy persons were recorded as they walked on the different terrains. The signals from the sound side of a transfemoral amputee were also recorded. The features of these signals were obtained using data processing techniques with an identification process developed for the identification of the terrain type. The procedure was simplified by using only the signals from three muscles. The identification process worked well in an intelligent prosthetic knee in a laboratory setting.

  20. Development of an underactuated prosthetic hand with the step motor

    Institute of Scientific and Technical Information of China (English)

    Zhao Dawei; Jin Minghe; Jiang Li; Shi Shicai; Liu Hong

    2006-01-01

    We present the development of a novel prosthetic hand based on the underactuated mechanism. The aim is focused on increasing its dexterity while keeping the same dimension and weight of a traditional prosthetic device. The hybrid step motor is used as the actuator, which enables the finger to keep enough high contact torque on the grasped object with less energy consumption provided by the holding torque. The grasping force of the finger is estimated from the base joint torque, and the adoption of impedance control has provided compliance in the grasping. Also a parallel observer is used to switch over between the impedance control and the torque holding mode. The experimental results show the effectiveness of the design and control strategy.

  1. Impact of advanced manufacturing technology on prosthetic and orthotic practice.

    Science.gov (United States)

    Jones, D

    1988-04-01

    Radical changes in the technology applied to prosthetics and orthotics are being proposed. This paper attempts to define the scope and character of advanced manufacturing technology and examines the rehabilitation problems which are or could be tackled. Lower-limb prosthetics has been the major area under investigation so far, but orthopaedic footwear, spinal orthotics and custom seating for the disabled have also been investigated using similar technological approaches. The whole process of patient measurement, device design, and component manufacture is conceived as an integrated system relying upon shape or tissue property sensing, computer based device design and computer-numerically-controlled or robot manufacturing processes. The aim is to retain flexibility for custom design which is necessary to provide for individual patients, and yet improve the rapidity and precision of overall device manufacture and service delivery.

  2. Customized mold radiotherapy with prosthetic apparatus for oral cancers

    International Nuclear Information System (INIS)

    Eight patients (6 males, 2 females; median age, 78 years; age range, 31-94 years) were treated by mold radiotherapy with a prosthetic apparatus for oral cancers between October 2006 and March 2013. The primary sites were the tongue in 3 cases, hard palate and buccal mucosa in 2 cases each, and oral floor in 1 case. The type of treatment consisted of radical radiotherapy and palliative radiotherapy in 2 cases each, and preoperative radiotherapy, postoperative radiotherapy, additional radiotherapy after external beam radiotherapy and systemic chemotherapy in 1 case each. Patients received 40-50 Gy in 8-10 fractions with mold radiotherapy. Two patients who received radical radiotherapy showed no signs of recurrence or metastasis. The present therapy contributed to patients' palliative, postoperative, and preoperative therapy. Mold radiotherapy with a prosthetic appliance was performed safely and was a useful treatment for several types of oral cancer. (author)

  3. Software Tool for the Prosthetic Foot Modeling and Stiffness Optimization

    Directory of Open Access Journals (Sweden)

    Matija Štrbac

    2012-01-01

    Full Text Available We present the procedure for the optimization of the stiffness of the prosthetic foot. The procedure allows the selection of the elements of the foot and the materials used for the design. The procedure is based on the optimization where the cost function is the minimization of the difference between the knee joint torques of healthy walking and the walking with the transfemural prosthesis. We present a simulation environment that allows the user to interactively vary the foot geometry and track the changes in the knee torque that arise from these adjustments. The software allows the estimation of the optimal prosthetic foot elasticity and geometry. We show that altering model attributes such as the length of the elastic foot segment or its elasticity leads to significant changes in the estimated knee torque required for a given trajectory.

  4. Contemporary management of prosthetic valve endocarditis: principals and future outlook.

    Science.gov (United States)

    O'Connor, Cormac T; Kiernan, Thomas J

    2015-05-01

    Infective endocarditis involving prosthetic valves accounts for 20% of all endocarditis cases. Rising in prevalence due to increasing placement of valvular prostheses, prosthetic valve endocarditis (PVE) is more difficult to diagnose by conventional methods, associated with more invasive infection and increased mortality. This report explores the existing literature in identifying a direct approach to the management of PVE; such as adjuncts to establishing a diagnosis (for instance positron emission tomography/computed tomography and radiolabeled leukocyte scintigraphy), the trends in specific pathogens associated with PVE and the recommended antimicrobials for each. The patterns of disease requiring surgical intervention are also highlighted and explored. In addition, a 5-year outlook offers consolidated knowledge on epidemiological trends of both culprit organisms and population subgroups suffering (and projected to suffer) from PVE. PMID:25865118

  5. Self-cleaning skin-like prosthetic polymer surfaces

    Science.gov (United States)

    Simpson, John T.; Ivanov, Ilia N.; Shibata, Jason

    2012-03-27

    An external covering and method of making an external covering for hiding the internal endoskeleton of a mechanical (e.g., prosthetic) device that exhibits skin-like qualities is provided. The external covering generally comprises an internal bulk layer in contact with the endoskeleton of the prosthetic device and an external skin layer disposed about the internal bulk layer. The external skin layer is comprised of a polymer composite with carbon nanotubes embedded therein. The outer surface of the skin layer has multiple cone-shaped projections that provide the external skin layer with superhydrophobicity. The carbon nanotubes are preferably vertically aligned between the inner surface and outer surface of the external skin layer in order to provide the skin layer with the ability to transmit heat. Superhydrophobic powders may optionally be used as part of the polymer composite or applied as a coating to the surface of the skin layer to enhance superhydrophobicity.

  6. Brain-Computer Interfaces for 1-D and 2-D Cursor Control: Designs Using Volitional Control of the EEG Spectrum or Steady-State Visual Evoked Potentials

    Science.gov (United States)

    Trejo, Leonard J.; Matthews, Bryan; Rosipal, Roman

    2005-01-01

    We have developed and tested two EEG-based brain-computer interfaces (BCI) for users to control a cursor on a computer display. Our system uses an adaptive algorithm, based on kernel partial least squares classification (KPLS), to associate patterns in multichannel EEG frequency spectra with cursor controls. Our first BCI, Target Practice, is a system for one-dimensional device control, in which participants use biofeedback to learn voluntary control of their EEG spectra. Target Practice uses a KF LS classifier to map power spectra of 30-electrode EEG signals to rightward or leftward position of a moving cursor on a computer display. Three subjects learned to control motion of a cursor on a video display in multiple blocks of 60 trials over periods of up to six weeks. The best subject s average skill in correct selection of the cursor direction grew from 58% to 88% after 13 training sessions. Target Practice also implements online control of two artifact sources: a) removal of ocular artifact by linear subtraction of wavelet-smoothed vertical and horizontal EOG signals, b) control of muscle artifact by inhibition of BCI training during periods of relatively high power in the 40-64 Hz band. The second BCI, Think Pointer, is a system for two-dimensional cursor control. Steady-state visual evoked potentials (SSVEP) are triggered by four flickering checkerboard stimuli located in narrow strips at each edge of the display. The user attends to one of the four beacons to initiate motion in the desired direction. The SSVEP signals are recorded from eight electrodes located over the occipital region. A KPLS classifier is individually calibrated to map multichannel frequency bands of the SSVEP signals to right-left or up-down motion of a cursor on a computer display. The display stops moving when the user attends to a central fixation point. As for Target Practice, Think Pointer also implements wavelet-based online removal of ocular artifact; however, in Think Pointer muscle

  7. Rapid Molecular Microbiologic Diagnosis of Prosthetic Joint Infection

    OpenAIRE

    Cazanave, Charles; Kerryl E. Greenwood-Quaintance; Hanssen, Arlen D.; Karau, Melissa J.; Schmidt, Suzannah M.; Gomez Urena, Eric O.; Mandrekar, Jayawant N.; OSMON, DOUGLAS R.; Lough, Lindsay E.; Pritt, Bobbi S.; Steckelberg, James M.; Patel, Robin

    2013-01-01

    We previously showed that culture of samples obtained by prosthesis vortexing and sonication was more sensitive than tissue culture for prosthetic joint infection (PJI) diagnosis. Despite improved sensitivity, culture-negative cases remained; furthermore, culture has a long turnaround time. We designed a genus-/group-specific rapid PCR assay panel targeting PJI bacteria and applied it to samples obtained by vortexing and sonicating explanted hip and knee prostheses, and we compared the result...

  8. Lactococcus garvieae Endocarditis on a Prosthetic Biological Aortic Valve.

    Science.gov (United States)

    Tsur, A; Slutzki, T; Flusser, D

    2015-09-01

    Lactococcus garvieae (LG) endocarditis is a rare disease in humans. There are only about 16 reported cases in the world. We report a 76-year-old male patient with LG endocarditis. In depth interview with the patient revealed that 2 weeks prior to admission, he had eaten sushi containing raw fish. Unlike many of the other infections reported, which were on a native mitral valve, our patient's vegetation was on a prosthetic aortic valve.

  9. Increasing risk of prosthetic joint infection after total hip arthroplasty

    DEFF Research Database (Denmark)

    Dale, Håvard; Fenstad, Anne M; Hallan, Geir;

    2012-01-01

    Background and purpose The risk of revision due to infection after primary total hip arthroplasty (THA) has been reported to be increasing in Norway. We investigated whether this increase is a common feature in the Nordic countries (Denmark, Finland, Norway, and Sweden). Materials and methods The...... explain this increase. We believe that there has been an actual increase in the incidence of prosthetic joint infections after THA....

  10. The Role of Prosthetic Dentistry in Mass Disaster Identification

    OpenAIRE

    Vermylen, Y.

    2002-01-01

    Dentistry plays a very important role in the identification of the victims in mass disasters. More than 50% of the identification work is concluded by dental means and investigation. Prosthetic work, and especially full rehabilitations with dental implants, crowns and bridges, is very valuable for dental identification. The biggest problems, however, are full upper and lower dentures. Marking of dentures would be a very valuable aid in identification procedures and very easy to do at a law...

  11. Peri-Prosthetic Infection in the Orthopedic Tumor Patient

    OpenAIRE

    Daniel Allison MD, MBA, FACS; Eddie Huang, MD; Elke Ahlmann, MD; Scott Carney, MD; Ling Wang, PA-C; Lawrence Menendez, MD, FACS

    2014-01-01

    Background: Infection complicates traditional joint reconstruction prostheses in up to 7% of cases, with even higher rates in oncologic cases.  Questions / Purposes: The authors ask if prosthetic infection in bone tumor patients is associated with any epidemiologic, treatment, or outcome variables that could influence management of these difficult conditions.  Patients and Methods: Authors retrospectively reviewed 329 consecutive bone tumor (malignant and benign) patients treated with h...

  12. PATIENT SATISFACTION WITH ORTHOPEDIC AND PROSTHETIC MEDICAL DEVICES

    Directory of Open Access Journals (Sweden)

    Ivona Malovecká

    2015-09-01

    Full Text Available Collecting information about patient satisfaction with orthopedic and prosthetic medical devices in terms of utility, tolerance, and compliance is essential for verifying and improving the quality of these devices. In addition, such information is useful for improving the patients’ quality of life, and the quality management systems of health care providers. This study assessed patient satisfaction with these devices from a sample of patients with orthopedic, neurologic, and rheumatic diseases at the Specialized Hospital for Orthopedic Prosthetics and at the premises of the Dispenser of Orthopedic and Prosthetic Medical Devices, both in Bratislava in the Slovak Republic. The assessment involved a translated and validated questionnaire about patient satisfaction with orthopedic and prosthetic medical devices to evaluate key factors of weight, fit, appearance, comfort, pain free, free of abrasiveness, ease of application, and durability of each device. The study samples consisted of patients with lower limb problems (42.5%, spine problems (26.9%, and a combination of leg and spine issues (25.9%. Orthopedic disease occurred in 73.6% of these patients, a combination of orthopedic and neurologic disease in 13.5%, and neurologic disease in 7.3%. Orthopedic insoles (36.3%, hip belts (17.6%, and the corset on the spine (5.2% were the most used devices. Overall, the medical devices rated highly, with a high proportion of patients voting “strongly satisfied” in five of the eight key factors (range 51.8 to 63.2%, followed by a moderately lower proportion for durability (43.5%, comfort (37.3%, and appearance (31.1%. The comfort in wearing the device received the greatest patient dissatisfaction (22.8% of patients, followed by appearance (12.4%, and then fit (7.3%.

  13. Fungal prosthetic joint infection after total knee arthroplasty

    OpenAIRE

    Reddy, Kankanala J; Shah, Jay D; Rohit V Kale; T Jayakrishna Reddy

    2013-01-01

    Fungal prosthetic joint infection after total knee arthroplasty (TKA) is a rare complication. Lacunae exist in the management of this complication. 62 year old lady presented with pain and swelling in left knee and was diagnosed as Candida tropicalis fungal infection after TKA. She underwent debridement, resection arthroplasty and antifungal plus antibiotic loaded cement spacer insertion, antifungal therapy with fluconazole followed by delayed revision TKA and further fluconazole therapy. Tot...

  14. Lactococcus garvieae Endocarditis on a Prosthetic Biological Aortic Valve.

    Science.gov (United States)

    Tsur, A; Slutzki, T; Flusser, D

    2015-09-01

    Lactococcus garvieae (LG) endocarditis is a rare disease in humans. There are only about 16 reported cases in the world. We report a 76-year-old male patient with LG endocarditis. In depth interview with the patient revealed that 2 weeks prior to admission, he had eaten sushi containing raw fish. Unlike many of the other infections reported, which were on a native mitral valve, our patient's vegetation was on a prosthetic aortic valve. PMID:25295408

  15. Design and development of a prosthetic implant for cardiovascular reconstructions

    OpenAIRE

    Ahmed, M.

    2011-01-01

    There is a significant worldwide demand for a small calibre vascular graft for use as a bypass or replacement conduit. Our lab has developed a novel nanocomposite poly- mer based on polyhedral oligomeric silsesquioxane and poly(carbonate-urea)urethane (POSS-PCU) which has displayed promising properties in vitro. In this thesis, POSS- PCU has been utilised to fabricate prosthetic small calibre conduits for use as arterial replacements. An important feature in determining the succes...

  16. Indium-111 leukocyte localization in infected prosthetic graft

    Energy Technology Data Exchange (ETDEWEB)

    Purnell, G.L.; Walker, C.W.; Allison, J.W.; Dalrymple, G.V. (Univ. of Arkansas for Medical Sciences, Little Rock (USA))

    1990-08-01

    Infective endocarditis can be difficult to prove, even in the face of strong clinical suspicion. A case in which standard methods of diagnosis failed to demonstrate endocarditis in a patient with recurrent Staphylococcus aureus bacteremia and porcine aortic valve is reported. An In-111 labelled leukocyte SPECT study demonstrated uptake in the aortic root and leaflets, and autopsy demonstrated vegetations on the leaflets. In-111 may prove useful in demonstrating endocarditis in patients with prosthetic valve infection.

  17. [[Medico-historical findings of (neuro-) prosthetics: an online survey].

    Science.gov (United States)

    Ohnemus, Dirk; Otte, Andreas

    2014-01-01

    This article presents an online survey on medico-historical (neuro-)prostheses. Important findings of the past 3000 years are outlined: toe prostheses from ancient Egypt, the Capua leg prosthesis, Götz von Berlichingen's artificial hands and Sauerbruch's prosthetic arm. These historical examples are compared with modern neuroprosthetics. It is also shown that historical prostheses were in no way primitive and, even more, that ancient people already used first intelligent medical engineering approaches. PMID:26548022

  18. Processing of Prosthetic Heart Valve Sounds from Anechoic Tank Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; Meyer, A W

    2001-03-20

    People with serious cardiac problems have had their life span extended with the development of the prosthetic heart valve. However, the valves operate continuously at approximately 39 million cycles per year and are therefore subject to structural failures either by faulty design or material fatigue. The development of a non-invasive technique using an acoustic contact microphone and sophisticated signal processing techniques has been proposed and demonstrated on limited data sets. In this paper we discuss an extension of the techniques to perform the heart valve tests in an anechoic like. Here the objective is to extract a ''pure'' sound or equivalently the acoustical vibration response of the prosthetic valves in a quiet environment. The goal is to demonstrate that there clearly exist differences between values which have a specific mechanical defect known as single leg separation (SLS) and non-defective valves known as intact (INT). We discuss the signal processing and results of anechoic acoustic measurements on 50 prosthetic valves in the tank. Finally, we show the results of the individual runs for each valve, point out any of the meaningful features that could be used to distinguish the SLS from INT and summarize the experiments.

  19. Evaluation of new suspension system for limb prosthetics

    Science.gov (United States)

    2014-01-01

    Background Good prosthetic suspension system secures the residual limb inside the prosthetic socket and enables easy donning and doffing. This study aimed to introduce, evaluate and compare a newly designed prosthetic suspension system (HOLO) with the current suspension systems (suction, pin/lock and magnetic systems). Methods All the suspension systems were tested (tensile testing machine) in terms of the degree of the shear strength and the patient’s comfort. Nine transtibial amputees participated in this study. The patients were asked to use four different suspension systems. Afterwards, each participant completed a questionnaire for each system to evaluate their comfort. Furthermore, the systems were compared in terms of the cost. Results The maximum tensile load that the new system could bear was 490 N (SD, 5.5) before the system failed. Pin/lock, magnetic and suction suspension systems could tolerate loads of580 N (SD, 8.5), 350.9 (SD, 7) and 310 N (SD, 8.4), respectively. Our subjects were satisfied with the new hook and loop system, particularly in terms of easy donning and doffing. Furthermore, the new system is considerably cheaper (35 times) than the current locking systems in the market. Conclusions The new suspension system could successfully retain the prosthesis on the residual limb as a good alternative for lower limb amputees. In addition, the new system addresses some problems of the existing systems and is more cost effective than its counterparts. PMID:24410918

  20. Iodine-125 orbital brachytherapy with a prosthetic implant in situ

    Energy Technology Data Exchange (ETDEWEB)

    Stannard, Clare [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Radiation Oncology; Maree, Gert; Munro, Roger [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Medical Physics; Lecuona, Karin [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Ophthalmology; Sauerwein, Wolfgang [Universitaetsklinikum Essen (Germany). Strahlenklinik, NCTeam

    2011-05-15

    Purpose: Brachytherapy is one method of irradiating the orbit after enucleation of an eye with a malignant tumor that has a potential to recur. It consists of 6 trains of I-125 seeds placed around the periphery of the orbit, a shorter central train, and a metal disc, loaded with seeds, placed beneath the eyelids. The presence of a prosthetic orbital implant requires omission of the central train and adjustment of the activity of the seeds in the anterior orbit around the prosthesis. Patients and Methods: This is a retrospective review of the technical modifications and outcome of 12 patients treated in this manner: 6 with retinoblastoma, 5 with malignant melanoma, and 1 with an intraocular rhabdomyosarcoma. The median dose was 35.5 Gy in 73 hours for retinoblastoma and 56 Gy in 141 hours for malignant melanoma. Patients with retinoblastoma and rhabdomyosarcoma also received chemotherapy. Results: The tubes can be placed satisfactorily around the prosthesis. The increased activity in the anterior half of the tubes produced comparable dose distributions. There have been no orbital recurrences, no extrusion of the prosthesis, and cosmesis is good. Conclusion: Insertion of a prosthetic implant at the time of enucleation greatly enhances the subsequent cosmetic appearance. This should be encouraged unless there is frank tumor in the orbit. Orbital brachytherapy without the central train continues to give excellent local control. The short treatment time and good cosmesis are added advantages. The patient is spared the expense and inconvenience of removing and replacing the prosthetic implant. (orig.)

  1. Prosthetic Leg Control in the Nullspace of Human Interaction

    Science.gov (United States)

    Gregg, Robert D.; Martin, Anne E.

    2016-01-01

    Recent work has extended the control method of virtual constraints, originally developed for autonomous walking robots, to powered prosthetic legs for lower-limb amputees. Virtual constraints define desired joint patterns as functions of a mechanical phasing variable, which are typically enforced by torque control laws that linearize the output dynamics associated with the virtual constraints. However, the output dynamics of a powered prosthetic leg generally depend on the human interaction forces, which must be measured and canceled by the feedback linearizing control law. This feedback requires expensive multi-axis load cells, and actively canceling the interaction forces may minimize the human's influence over the prosthesis. To address these limitations, this paper proposes a method for projecting virtual constraints into the nullspace of the human interaction terms in the output dynamics. The projected virtual constraints naturally render the output dynamics invariant with respect to the human interaction forces, which instead enter into the internal dynamics of the partially linearized prosthetic system. This method is illustrated with simulations of a transfemoral amputee model walking with a powered knee-ankle prosthesis that is controlled via virtual constraints with and without the proposed projection. PMID:27746585

  2. Mitral isthmus ablation in patients with prosthetic mitral valves

    Institute of Scientific and Technical Information of China (English)

    LONG De-yong; MA Chang-sheng; JIANG Hong; DONG Jian-zeng; LIU Xing-peng; HUANG He; TANG Yan-hong; WU Gang; HUANG Cong-xin

    2010-01-01

    Background Previous studies have investigated the technique of linear ablation at the mitral isthmus (MI) in patients with idopathic atrial fibrillation (AF), but MI ablation in patients with prosthetic natural mitral valves (MVs) was not described in detail. Present study sought to summarize our initial experience of ablating MI in patients with prosthetic MVs Methods Patients with drug refractory AF and prosthetic MVs were eligible for this study, and the patients with natural MVs but received MI ablation served as control group. Left atrium (LA) mapping and ablation was carried out guided by CARTO system. The anatomy of MI was assessed via computer topography scan.Results During the study period, a consecutive of 19 patients (male/female=12/7, mean age of (48±-6) years) with prosthetic MVs (16 with metal valves, 3 with biologic valves) entered for AF ablation, other 35 patients served as control group. In study group, mapping along MI documented lower voltages ((2.0±1.0) vs. (3.1±1.3) mV, P=0.002), more fragmented potentials (19/19 vs. 20/15, P<0.001 ), and higher impedance ((132±34) vs. (110±20) Ω, P=0.004). After initial ablation, more residual gaps along the MI lesions were found in study group (2.4±0.4 vs. 1.7±0.3, P <0.001). The mean length of MI ((6.2±3.3) vs. (7.1±2.3) cm, P=0.25) was comparable between 2 groups, but the MI in study group was much thicker ((3.1 ±1.8) vs. (2.1±1.07) cm, P=0.01 ) and all were found as pouch type (19/19 vs. 2/35, P <0.001). The follow-up results were comparable (65.1% vs. 72.3%, P=0.30).Conclusion For patients with prosthetic MVs, linear ablation at MI could be successfully carried out despite anatomical and pathological changes.

  3. Novel Method to Evaluate Angular Stiffness of Prosthetic Feet From Linear Compression Tests

    OpenAIRE

    Adamczyk, Peter G.; Roland, Michelle; Hahn, Michael E.

    2013-01-01

    Lower limb amputee gait during stance phase is related to the angular stiffness of the prosthetic foot, which describes the dependence of ankle torque on angular progression of the shank. However, there is little data on angular stiffness of prosthetic feet, and no method to directly measure it has been described. The objective of this study was to derive and evaluate a method to estimate the angular stiffness of prosthetic feet using a simple linear compression test. Linear vertical compress...

  4. JRRD Then & Now: VA Prosthetic and Sensory Aids Service—65 Years of Progress

    OpenAIRE

    Lucille Beck, PhD

    2013-01-01

    The JRRD article written by Stewart in 1965 entitled “Twenty Years of Progress” highlighted the progress of the Veteran Administration’s Prosthetic and Sensory Aids Service since World War II. Recognizing the importance of prosthetic and sensory aids to Veteran healthcare during those early days set the foundation for the department of today to become the largest and most comprehensive provider of prosthetic devices and sensory aids in the world.

  5. Pregnancy with prosthetic heart valves - 30 years' nationwide experience in Denmark

    DEFF Research Database (Denmark)

    Sillesen, Martin; Hjortdal, Vibeke; Vejlstrup, Niels;

    2011-01-01

    Pregnancy in women with prosthetic heart valves remains a risk factor for both mother and fetus, but unselected and unbiased outcome and complication data remain scarce. We analyzed nationwide outcome data from 1977 to 2007 for all pregnancies in women with prosthetic valves.......Pregnancy in women with prosthetic heart valves remains a risk factor for both mother and fetus, but unselected and unbiased outcome and complication data remain scarce. We analyzed nationwide outcome data from 1977 to 2007 for all pregnancies in women with prosthetic valves....

  6. A prosthetic knee using magnetorhelogical fluid damper for above-knee amputees

    Science.gov (United States)

    Park, Jinhyuk; Choi, Seung-Bok

    2015-04-01

    A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.

  7. Prosthetic avian vocal organ controlled by a freely behaving bird based on a low dimensional model of the biomechanical periphery.

    Directory of Open Access Journals (Sweden)

    Ezequiel M Arneodo

    Full Text Available Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform.

  8. State-of-the-art research in lower-limb prosthetic biomechanics-socket interface: a review.

    Science.gov (United States)

    Mak, A F; Zhang, M; Boone, D A

    2001-01-01

    Scientific studies have been conducted to quantify attributes that may be important in the creation of more functional and comfortable lower-limb prostheses. The prosthesis socket, a human-machine interface, has to be designed properly to achieve satisfactory load transmission, stability, and efficient control for mobility. The biomechanical understanding of the interaction between prosthetic socket and the residual limb is fundamental to such goals. The purpose of this paper is to review the recent research literature on socket biomechanics, including socket pressure measurement, friction-related phenomena and associated properties, computational modeling, and limb tissue responses to external mechanical loads and other physical conditions at the interface. There is no doubt that improved biomechanical understanding has advanced the science of socket fitting. However, the most recent advances in the understanding of stresses experienced at the residual limb have not yet led to enough clinical consensus that could fundamentally alter clinical practice. Efforts should be made to systematically identify the major discrepancies. Further research should be directed to address the critical controversies and the associated technical challenges. Developments should be guided to offer clinicians the quantification and visualization of the interaction between the residual limb and the prosthetic socket. An understanding of comfort and optimal load transfer as patterns of socket interface stress could culminate in socket design expert systems.

  9. Psycho-physiological assessment of a prosthetic hand sensory feedback system based on an auditory display: a preliminary study

    Directory of Open Access Journals (Sweden)

    Gonzalez Jose

    2012-06-01

    Full Text Available Abstract Background Prosthetic hand users have to rely extensively on visual feedback, which seems to lead to a high conscious burden for the users, in order to manipulate their prosthetic devices. Indirect methods (electro-cutaneous, vibrotactile, auditory cues have been used to convey information from the artificial limb to the amputee, but the usability and advantages of these feedback methods were explored mainly by looking at the performance results, not taking into account measurements of the user’s mental effort, attention, and emotions. The main objective of this study was to explore the feasibility of using psycho-physiological measurements to assess cognitive effort when manipulating a robot hand with and without the usage of a sensory substitution system based on auditory feedback, and how these psycho-physiological recordings relate to temporal and grasping performance in a static setting. Methods 10 male subjects (26+/-years old, participated in this study and were asked to come for 2 consecutive days. On the first day the experiment objective, tasks, and experiment setting was explained. Then, they completed a 30 minutes guided training. On the second day each subject was tested in 3 different modalities: Auditory Feedback only control (AF, Visual Feedback only control (VF, and Audiovisual Feedback control (AVF. For each modality they were asked to perform 10 trials. At the end of each test, the subject had to answer the NASA TLX questionnaire. Also, during the test the subject’s EEG, ECG, electro-dermal activity (EDA, and respiration rate were measured. Results The results show that a higher mental effort is needed when the subjects rely only on their vision, and that this effort seems to be reduced when auditory feedback is added to the human-machine interaction (multimodal feedback. Furthermore, better temporal performance and better grasping performance was obtained in the audiovisual modality. Conclusions The performance

  10. Dynamic changes in the distribution and time course of blood-brain barrier-permeative nitroxides in the mouse head with EPR imaging: visualization of blood flow in a mouse model of ischemia.

    Science.gov (United States)

    Emoto, Miho C; Sato-Akaba, Hideo; Hirata, Hiroshi; Fujii, Hirotada G

    2014-09-01

    Electron paramagnetic resonance (EPR) imaging using nitroxides as redox-sensitive probes is a powerful, noninvasive method that can be used under various physiological conditions to visualize changes in redox status that result from oxidative damage. Two blood-brain barrier-permeative nitroxides, 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (HMP) and 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy (MCP), have been widely used as redox-sensitive probes in the brains of small animals, but their in vivo distribution and properties have not yet been analyzed in detail. In this study, a custom-made continuous-wave three-dimensional (3D) EPR imager was used to obtain 3D EPR images of mouse heads using MCP or HMP. This EPR imager made it possible to take 3D EPR images reconstructed from data from 181 projections acquired every 60s. Using this improved EPR imager and magnetic resonance imaging, the distribution and reduction time courses of HMP and MCP were examined in mouse heads. EPR images of living mice revealed that HMP and MCP have different distributions and different time courses for entering the brain. Based on the pharmacokinetics of the reduction reactions of HMP and MCP in the mouse head, the half-lives of HMP and MCP were clearly and accurately mapped pixel by pixel. An ischemic mouse model was prepared, and the half-life of MCP was mapped in the mouse head. Compared to the half-life in control mice, the half-life of MCP in the ischemic model mouse brain was significantly increased, suggesting a shift in the redox balance. This in vivo EPR imaging method using BBB-permeative MCP is a useful noninvasive method for assessing changes in the redox status in mouse brains under oxidative stress.

  11. Dynamic Facial Prosthetics for Sufferers of Facial Paralysis

    Directory of Open Access Journals (Sweden)

    Fergal Coulter

    2011-10-01

    Full Text Available BackgroundThis paper discusses the various methods and the materialsfor the fabrication of active artificial facial muscles. Theprimary use for these will be the reanimation of paralysedor atrophied muscles in sufferers of non-recoverableunilateral facial paralysis.MethodThe prosthetic solution described in this paper is based onsensing muscle motion of the contralateral healthy musclesand replicating that motion across a patient’s paralysed sideof the face, via solid state and thin film actuators. Thedevelopment of this facial prosthetic device focused onrecreating a varying intensity smile, with emphasis ontiming, displacement and the appearance of the wrinklesand folds that commonly appear around the nose and eyesduring the expression.An animatronic face was constructed with actuations beingmade to a silicone representation musculature, usingmultiple shape-memory alloy cascades. Alongside theartificial muscle physical prototype, a facial expressionrecognition software system was constructed. This formsthe basis of an automated calibration and reconfigurationsystem for the artificial muscles following implantation, soas to suit the implantee’s unique physiognomy.ResultsAn animatronic model face with silicone musculature wasdesigned and built to evaluate the performance of ShapeMemory Alloy artificial muscles, their power controlcircuitry and software control systems. A dual facial motionsensing system was designed to allow real time control overmodel – a piezoresistive flex sensor to measure physicalmotion, and a computer vision system to evaluate real toartificial muscle performance.Analysis of various facial expressions in real subjects wasmade, which give useful data upon which to base thesystems parameter limits.ConclusionThe system performed well, and the various strengths andshortcomings of the materials and methods are reviewedand considered for the next research phase, when newpolymer based artificial muscles are constructed

  12. A Brain-Machine Interface Instructed by Direct Intracortical Microstimulation

    OpenAIRE

    O'Doherty, Joseph E; Lebedev, Mikhail A.; Hanson, Timothy L; Fitzsimmons, Nathan A.; Nicolelis, Miguel A.L.

    2009-01-01

    Brain–machine interfaces (BMIs) establish direct communication between the brain and artificial actuators. As such, they hold considerable promise for restoring mobility and communication in patients suffering from severe body paralysis. To achieve this end, future BMIs must also provide a means for delivering sensory signals from the actuators back to the brain. Prosthetic sensation is needed so that neuroprostheses can be better perceived and controlled. Here we show that a direct intracort...

  13. Xeroderma Pigmentosum with Melanoma of Face and Its Prosthetic Management

    International Nuclear Information System (INIS)

    Xeroderma pigmentosum is a rare genetic disorder, characterized by cutaneous, ocular and neurological symptoms. Squamous cell carcinoma and melanoma are also its secondary characters. This case report is about maxillofacial prosthetic management of a 10 years old child presented with xeroderma pigmentosum. The nose of the patient was excised surgically due to melanoma. This case report elaborates the role of prosthodontist and the whole procedure of constructing the nasal prosthesis via conventional technique by using the patient's sibling nasal form as template. Regular follow up revealed marked improvement in esthetics, function and ultimately patient's quality of life. (author)

  14. Development and marketing of a prosthetic urinary control valve system

    Science.gov (United States)

    Tenney, J. B., Jr.; Rabinowitz, R.; Rogers, D. W.; Harrison, H. N.

    1983-01-01

    An implantable prosthetic for the control of urinary incontinence was developed and marketed. Three phases are presented: bench development studies, animal trials, and human clinical trials. This work was performed under the direction of a Research Team at Rochester General Hospital (RGH). Bench trials were completed on prototype hardware and provided early verification of the device's ability to withstand repeated cyclic testing. Configurational variants were evaluated and a preferred design concept was established. Silicone rubber (medical grade) was selected as the preferred material for the prosthesis.

  15. Artifact reduction strategies for prosthetic heart valve CT imaging

    OpenAIRE

    Habets, Jesse; Symersky, Petr; Leiner, Tim; de Mol, Bas A. J. M.; Willem P Th M Mali; Budde, Ricardo P.J.

    2012-01-01

    Multislice CT evaluation of prosthetic heart valves (PHV) is limited by PHV-related artifacts. We assessed the influence of different kV settings, a metal artifact reduction filter (MARF) and an iterative reconstruction algorithm (IR) on PHV-induced artifacts in an in vitro model. A Medtronic-Hall tilting disc and St Jude bileafet PHV were imaged using a 64-slice scanner with 100 kV/165 mAs, 120 kV/100 mAs, 140 kV/67 mAs at an equal CTDIvol. Images were reconstructed with (1) filtered back pr...

  16. Reconstruction of Exenterated Orbit using Combined Surgical and Prosthetic Approach.

    Science.gov (United States)

    Prithviraj, D R; Gupta, Anish; Khare, Sumit; Garg, Pooja; Pujari, Malesh

    2011-05-01

    Reconstruction of an exenterated orbit remains a challenge. Orbital prostheses are nowadays are made of silicone elastomers. A major limitation with silicone orbital prostheses is their relatively short life span. This case report describes the treatment of a patient with an exenterated orbit using a combined surgical and prosthetic approach. The upper and lower eyelids were reconstructed surgically using a deltopectoral flap. A sectional eye prosthesis was made and placed in the modified bottle-neck shaped defect to restore the patient's appearance and confidence. PMID:21969903

  17. Prosthetic rehabilitation of a patient with facial mucormycosis

    Directory of Open Access Journals (Sweden)

    Digvijay Sanjay Deshpande

    2014-01-01

    Full Text Available Facial mucormycosis is a known complication in patients with immunological or metabolic compromise. Mainstay of treatment includes reversal of the compromised state, systemic antifungals and repeated radical debridements. The resultant deformity following debridement causes gross morbidity and psycho-social embarrassment. Surgical reconstruction is difficult on account of co-morbid diseases. Nonsurgical prosthetic rehabilitation gives fairly accurate correction in these patients. We report a case of a 62-year-old male diabetic with facial mucormycosis where debridement resulted in a gross morbid defect. However, effective rehabilitation was achieved using extraoral prosthesis.

  18. The role of virtual articulator in prosthetic and restorative dentistry.

    Science.gov (United States)

    Koralakunte, Pavankumar Ravi; Aljanakh, Mohammad

    2014-07-01

    Virtual reality is a computer based technology linked with the future of dentistry and dental practice. The virtual articulator is one such application in prosthetic and restorative dentistry based on virtual reality that will significantly reduce the limitations of the mechanical articulator, and by simulation of real patient data, allow analyses with regard to static and dynamic occlusion as well as to jaw relation. It is the purpose of this article to present the concepts and strategies for a future replacement of the mechanical articulator by a virtual one. Also, a brief note on virtual reality haptic system has been highlighted along with newly developed touch enabled virtual articulator.

  19. The efficacy of 99mTc-ciprofloxacin (infecton) imaging in suspected prosthetic infection following total knee replacement arthroplasty (pilot study)

    International Nuclear Information System (INIS)

    The aims of this study were 1) to increase the labelling efficiency of 99mTc-ciprofloxacin (infecton) and 2) to determine the value of infecton imaging in demonstrating infection following total knee replacement arthroplasty (TKRA). Five patients (4 female, 1 male: mean age 52.8±13.5 years, both TKRA in 3 pt) with suspected prosthetic infective conditions were included. In order to increase labelling efficiency, infection was labelled with stannous tartrate instead of previousely used formamidine sulfinic acid (FSA). Immediate perfusion, 5min blood pool, 1hr, 4hr and 24hr delayed images were perfomed. All images were blindly interpreted by two independent observers with visual findings being classified according to a four-grade scale(0.1.2.3). Images graded 0 and 1, and also those regions which showed faintly increase or unchanged uptake grade on late images as compared with early images, were classified as negative; grades 2 and 3 were classified as positive. The diagnosis was confirmed by intraoperative microbiological / histological findings or by the presence of gross purulence. Labelling efficiency increased up to over 98% with formation of radiocolloid less than 1%. All of four pt with prosthetic infection showed positive infecton images but one pt with sterile loosening of prosthesis showed negative infection images. The easy availability as well as new labelling technique make infecton imaging the better option for the detection of prosthetic orthopedic infection

  20. Brain F-18 FDG PET for localization of epileptogenic zones in frontal lobe epilepsy: visual assessment and statistical parametric mapping analysis

    International Nuclear Information System (INIS)

    We evaluated the sensitivity of the F-18 FDG PET by visual assessment and statistical parametric mapping (SPM) analysis for the localization of the epileptogenic zones in frontal lobe epilepsy. Twenty-four patients with frontal lobe epilepsy were examined. All patients exhibited improvements after surgical resection (Engel class I or II). Upon pathological examination, 18 patients revealed cortical dysplasia, 4 patients revealed tumor, and 2 patients revealed cortical scar. The hypometabolic lesions were found in F-18 FDG PET by visual assessment and SPM analysis. On SPM analysis, cutoff threshold was changed. MRI showed structural lesions in 12 patients and normal results in the remaining 12. F-18 FDG PET correctly localized epileptogenic zones in 13 patients (54%) by visual assessment. Sensitivity of F-18 FDG PET in MR-negative patients (50%) was similar to that in MR-positive patients (67%). On SPM analysis, sensitivity deceased according to the decrease of p value. Using uncorrected p value of 0.05 as threshold, sensitivity of SPM analysis was 63%, which was not statistically different from that of visual assessment. F-18 FDG PET was sensitive in finding epileptogenic zones by revealing hypometabolic areas even in MR-negative patients with frontal lobe epilepsy as well as in MR-positive patients. SPM analysis showed comparable sensitivity to visual assessment and could be used as an aid in the diagnosis of epileptogenic zones in frontal lobe epilepsy

  1. Assistive peripheral prosthetic vision aids perception and mobility in outdoor environments: A virtual-reality simulation study.

    Science.gov (United States)

    Zapf, Marc Patrick H; Boon, Mei-Ying; Lovell, Nigel H; Suaning, Gregg J

    2015-08-01

    Retinitis pigmentosa (RP) causes visual field (VF) constriction due to progressive loss of photoreceptors, typically from the retinal periphery to the fovea. Retinal prostheses offer vision restoration via electrode implantation and stimulation near the fovea, thereby eliciting articifial percepts, so-called phosphenes in the center VF. Although foveal photoreceptors can persist for prolonged periods of time, bionic therapy is usually restricted to stages of RP with complete vision loss. However, persons with RP experience mobility impairment from peripherally restricted VFs much earlier. Consequently, the amount of visual scanning necessary for navigation is increased, and maintaining a steady pace is challenging. Receiving a retinal implant at this early stage might be feasible. We investigated the potential of a peripheral visual prosthesis coexisting with central residual vision to facilitate scene perception and mobility. Simulating prosthetic and residual vision in a virtual mobility environment, we found that assistive phosphene layouts were associated with reductions in visual scanning-related head movements of up to 42.1%, body rotations of up to 30%, and up to 45% lower frequency of stopping when circumventing low-lying obstacles, pedestrians and following a path. Further research on early implantation of retinal prostheses for the peripheral VF is therefore advised. PMID:26736589

  2. A mechanism to compensate undesired stiffness in joints of prosthetic hands

    NARCIS (Netherlands)

    Smit, G.; Plettenbrug, D.H.; Van der Helm, F.C.T.

    2014-01-01

    Background: Cosmetic gloves that cover a prosthetic hand have a parasitic positive stiffness that counteracts the flexion of a finger joint. Objectives: Reducing the required input torque to move a finger of a prosthetic hand by compensating the parasitic stiffness of the cosmetic glove. Study des

  3. Prosthetic joint infection due to Lysobacter thermophilus diagnosed by 16S rRNA gene sequencing.

    Science.gov (United States)

    Dhawan, B; Sebastian, S; Malhotra, R; Kapil, A; Gautam, D

    2016-01-01

    We report the first case of prosthetic joint infection caused by Lysobacter thermophilus which was identified by 16S rRNA gene sequencing. Removal of prosthesis followed by antibiotic treatment resulted in good clinical outcome. This case illustrates the use of molecular diagnostics to detect uncommon organisms in suspected prosthetic infections.

  4. Shape sensing for computer aided below-knee prosthetic socket design.

    Science.gov (United States)

    Fernie, G R; Griggs, G; Bartlett, S; Lunau, K

    1985-04-01

    Shape sensing is useful in the computer aided prosthetic fitting process for two purposes. 1. To input characteristic prosthetic shapes that have been developed over the years through the experience of prosthetists. 2. To provide an accurate and rapid measurement of the anatomical shape of the stump. This paper describes two instruments which have been built to meet these objectives.

  5. Prosthetic fitting, use, and satisfaction following lower-limb amputation: A prospective study

    Directory of Open Access Journals (Sweden)

    Joseph B. Webster, MD

    2013-01-01

    Full Text Available Providing a satisfactory, functional prosthesis following lower-limb amputation is a primary goal of rehabilitation. The objectives of this study were to describe the rate of successful prosthetic fitting over a 12 mo period; describe prosthetic use after amputation; and determine factors associated with greater prosthetic fitting, function, and satisfaction. The study design was a multicenter prospective cohort study of individuals undergoing their first major lower-limb amputation because of vascular disease and/or diabetes. At 4 mo, unsuccessful prosthetic fitting was significantly associated with depression, prior arterial reconstruction, diabetes, and pain in the residual limb. At 12 mo, 92% of all subjects were fit with a prosthetic limb and individuals with transfemoral amputation were significantly less likely to have a prosthesis fit. Age older than 55 yr, diagnosis of a major depressive episode, and history of renal dialysis were associated with fewer hours of prosthetic walking. Subjects who were older, had experienced a major depressive episode, and/or were diagnosed with chronic obstructive pulmonary disease had greater functional restriction. Thus, while most individuals achieve successful prosthetic fitting by 1 yr following a first major nontraumatic lower-limb amputation, a number of medical variables and psychosocial factors are associated with prosthetic fitting, utilization, and function.

  6. Brown-Pigmented Mycobacterium mageritense as a Cause of Prosthetic Valve Endocarditis and Bloodstream Infection.

    Science.gov (United States)

    McMullen, Allison R; Mattar, Caline; Kirmani, Nigar; Burnham, Carey-Ann D

    2015-08-01

    Mycobacterium spp. are a rare cause of endocarditis. Herein, we describe a case of Mycobacterium mageritense prosthetic valve endocarditis. This organism produced an unusual brown pigment on solid media. Cultures of valve tissue for acid-fast bacilli might be considered in some cases of apparently culture-negative prosthetic valve endocarditis.

  7. Specificity of auditory-guided visual perceptual learning suggests crossmodal plasticity in early visual cortex

    OpenAIRE

    Beer, Anton L.; Watanabe, Takeo

    2009-01-01

    Sounds modulate visual perception. Blind humans show altered brain activity in early visual cortex. However, it is still unclear whether crossmodal activity in visual cortex results from unspecific top-down feedback, a lack of visual input, or genuinely reflects crossmodal interactions at early sensory levels. We examined how sounds affect visual perceptual learning in sighted adults. Visual motion discrimination was tested prior to and following eight sessions in which observers were exposed...

  8. Septic arthritis caused by Mycobacterium fortuitum and Mycobacterium abscessus in a prosthetic knee joint: case report and review of literature.

    Science.gov (United States)

    Wang, Shu-Xiang; Yang, Chang-Jen; Chen, Yu-Chuan; Lay, Chorng-Jang; Tsai, Chen-Chi

    2011-01-01

    Nontuberculous mycobacterium (NTM) is an infrequent cause of prosthetic knee joint infections. Simultaneous infection with different NTM species in a prosthetic knee joint has not been previously reported. A case of prosthetic knee joint infection caused by Mycobacterium abscessus and M. fortuitum is described in this report. The patient was successfully treated with adequate antibiotics and surgery. The clinical features of sixteen previously reported cases of prosthetic knee joint infection caused by NTM are reviewed.

  9. Mechanical design and performance specifications of anthropomorphic prosthetic hands: A review

    Directory of Open Access Journals (Sweden)

    Joseph T. Belter, MS, BS

    2013-08-01

    Full Text Available In this article, we set forth a detailed analysis of the mechanical characteristics of anthropomorphic prosthetic hands. We report on an empirical study concerning the performance of several commercially available myoelectric prosthetic hands, including the Vincent, iLimb, iLimb Pulse, Bebionic, Bebionic v2, and Michelangelo hands. We investigated the finger design and kinematics, mechanical joint coupling, and actuation methods of these commercial prosthetic hands. The empirical findings are supplemented with a compilation of published data on both commercial and prototype research prosthetic hands. We discuss numerous mechanical design parameters by referencing examples in the literature. Crucial design trade-offs are highlighted, including number of actuators and hand complexity, hand weight, and grasp force. Finally, we offer a set of rules of thumb regarding the mechanical design of anthropomorphic prosthetic hands.

  10. A computational method for comparing the behavior and possible failure of prosthetic implants

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, C.; Hollerbach, K.; Perfect, S.; Underhill, K.

    1995-05-01

    Prosthetic joint implants currently in use exhibit high Realistic computer modeling of prosthetic implants provides an opportunity for orthopedic biomechanics researchers and physicians to understand possible in vivo failure modes, without having to resort to lengthy and costly clinical trials. The research presented here is part of a larger effort to develop realistic models of implanted joint prostheses. The example used here is the thumb carpo-metacarpal (cmc) joint. The work, however, can be applied to any other human joints for which prosthetic implants have been designed. Preliminary results of prosthetic joint loading, without surrounding human tissue (i.e., simulating conditions under which the prosthetic joint has not yet been implanted into the human joint), are presented, based on a three-dimensional, nonlinear finite element analysis of three different joint implant designs.

  11. Mechanical design and performance specifications of anthropomorphic prosthetic hands: a review.

    Science.gov (United States)

    Belter, Joseph T; Segil, Jacob L; Dollar, Aaron M; Weir, Richard F

    2013-01-01

    In this article, we set forth a detailed analysis of the mechanical characteristics of anthropomorphic prosthetic hands. We report on an empirical study concerning the performance of several commercially available myoelectric prosthetic hands, including the Vincent, iLimb, iLimb Pulse, Bebionic, Bebionic v2, and Michelangelo hands. We investigated the finger design and kinematics, mechanical joint coupling, and actuation methods of these commercial prosthetic hands. The empirical findings are supplemented with a compilation of published data on both commercial and prototype research prosthetic hands. We discuss numerous mechanical design parameters by referencing examples in the literature. Crucial design trade-offs are highlighted, including number of actuators and hand complexity, hand weight, and grasp force. Finally, we offer a set of rules of thumb regarding the mechanical design of anthropomorphic prosthetic hands.

  12. A systematic literature review of the effect of different prosthetic components on human functioning with a lower-limb prosthesis

    NARCIS (Netherlands)

    van der Linde, H; Hofstad, CJ; Postema, K; Geertzen, JHB

    2004-01-01

    A correct prosthetic prescription can be derived from adapting the functional benefits of a prosthesis to the functional needs of the prosthetic user. For adequate matching, the functional abilities of the amputees are of value, as well as the technical and functional aspects of the various prosthet

  13. Outdoor dynamic subject-specific evaluation of internal stresses in the residual limb: hydraulic energy-stored prosthetic foot compared to conventional energy-stored prosthetic feet.

    Science.gov (United States)

    Portnoy, Sigal; Kristal, Anat; Gefen, Amit; Siev-Ner, Itzhak

    2012-01-01

    The prosthetic foot plays an important role in propelling, breaking, balancing and supporting body loads while the amputee ambulates on different grounds. It is therefore important to quantify the effect of the prosthetic foot mechanism on biomechanical parameters, in order to prevent pressure ulcers and deep tissue injury. Our aim was to monitor the internal stresses in the residuum of transtibial amputation (TTA) prosthetic-users ambulating on different terrains, which the amputees encounter during their daily activities, i.e. paved floor, grass, ascending and descending stairs and slope. We specifically aimed to compare between the internal stresses in the TTA residuum of amputees ambulating with a novel hydraulic prosthetic foot compared to conventional energy storage and return (ESR) prosthetic feet. Monitoring of internal stresses was accomplished using a portable subject-specific real-time internal stress monitor. We found significant decrease (phydraulic foot, compared to walking with ESR feet. The loading rate calculated while ambulating with the hydraulic foot was at least three times lower than the loading rate calculated while ambulating with the ESR foot. Although the average decrease in internal stresses was ≈ 2-fold larger when replacing single-toe ESR feet with the hydraulic foot than when replacing split-toed ESR feet with the hydraulic foot, the differences were statistically insignificant. Our findings suggest that using a hydraulic prosthetic foot may protect the distal tibial end of the TTA residuum from high stresses, therefore preventing pressure-related injury and pain.

  14. Prosthetic leg powered by MR brake and SMA wires

    Science.gov (United States)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  15. Dynamic interface pressure distributions of two transtibial prosthetic socket concepts.

    Science.gov (United States)

    Dumbleton, Tim; Buis, Arjan W P; McFadyen, Angus; McHugh, Brendan F; McKay, Geoff; Murray, Kevin D; Sexton, Sandra

    2009-01-01

    In this study, we investigated and compared the dynamic interface pressure distribution of hands-off and hands-on transtibial prosthetic systems by means of pressure mapping. Of the 48 established unilateral amputees recruited, half (n = 24) had been wearing pressure-cast prostheses (IceCast Compact) and the other half (n = 24) had been wearing hand-cast sockets of the patellar tendon bearing design. We measured the dynamic pressure profile of more than 90% of the area within each prosthetic socket by means of four Tekscan F-Scan socket transducer arrays. We compared the interface pressure between socket concepts. We found that the distribution of dynamic pressure at the limb-socket interface was similar for the two intervention (socket prescription) groups. However, a significant difference was found in the magnitude of the interface pressure between the two socket concepts; the interface pressures recorded in the hands-off sockets were higher than those seen in the hands-on concept. Despite the differences in interface pressure, the level of satisfaction with the sockets was similar between subject groups. The sockets instrumented for this study had been in daily use for at least 6 months, with no residual-limb health problems.

  16. Consumer satisfaction with the services of prosthetics and orthotics facilities.

    Science.gov (United States)

    Bosmans, Joline; Geertzen, Jan; Dijkstra, Pieter U

    2009-03-01

    Consumer satisfaction with the services provided in a prosthetics and orthotics (P&O) facility has seldom been studied. The aim of this study was to analyze consumer satisfaction regarding the services provided by 15 P&O facilities in The Netherlands. Consumers (n = 1,364) of these P&O facilities who were fitted with a prosthesis, orthopaedic shoes, an orthosis, or another device, were asked to rate the overall services provided and whether they were satisfied with the device provided and its delivery time. Additionally, they filled in a modified SERVQUAL questionnaire (see Appendix). Consumers gave the service provided by P&O facilities a mean overall rating of 8.1. The highest ratings were given by consumers fitted with a prosthesis (mean overall rating of services: 8.4). In total, 78% of the consumers were satisfied with the device provided and 93% with the delivery time. The results of our study showed that, on the SERVQUAL, 50% of the statements fulfilled the criteria for a satisfactory quality of the services. The overall consumer rating of the service provided by P&O facilities is high and depends on the device provided. The outcomes on the SERVQUAL were moderate. In future, it is important to study consumer satisfaction more extensively in order to improve the quality of P&O services in daily practice. Additionally, specific questionnaires need to be developed to measure all aspects of prosthetic and orthotic care, with the aim to improve the services. PMID:19235068

  17. Quantifying prosthetic gait deviation using simple outcome measures

    Science.gov (United States)

    Kark, Lauren; Odell, Ross; McIntosh, Andrew S; Simmons, Anne

    2016-01-01

    AIM: To develop a subset of simple outcome measures to quantify prosthetic gait deviation without needing three-dimensional gait analysis (3DGA). METHODS: Eight unilateral, transfemoral amputees and 12 unilateral, transtibial amputees were recruited. Twenty-eight able-bodied controls were recruited. All participants underwent 3DGA, the timed-up-and-go test and the six-minute walk test (6MWT). The lower-limb amputees also completed the Prosthesis Evaluation Questionnaire. Results from 3DGA were summarised using the gait deviation index (GDI), which was subsequently regressed, using stepwise regression, against the other measures. RESULTS: Step-length (SL), self-selected walking speed (SSWS) and the distance walked during the 6MWT (6MWD) were significantly correlated with GDI. The 6MWD was the strongest, single predictor of the GDI, followed by SL and SSWS. The predictive ability of the regression equations were improved following inclusion of self-report data related to mobility and prosthetic utility. CONCLUSION: This study offers a practicable alternative to quantifying kinematic deviation without the need to conduct complete 3DGA. PMID:27335814

  18. Recapitulating flesh with silicon and steel: advancements in upper extremity robotic prosthetics.

    Science.gov (United States)

    Lee, Brian; Attenello, Frank J; Liu, Charles Y; McLoughlin, Michael P; Apuzzo, Michael L J

    2014-01-01

    With the loss of function of an upper extremity because of stroke or spinal cord injury or a physical loss from amputation, an individual's life is forever changed, and activities that were once routine become a magnitude more difficult. Much research and effort have been put into developing advanced robotic prostheses to restore upper extremity function. For patients with upper extremity amputations, previously crude prostheses have evolved to become exceptionally functional. Because the upper extremities can perform a wide variety of activities, several types of upper extremity prostheses are available ranging from passive cosmetic limbs to externally powered robotic limbs. In addition, new developments in brain-machine interface are poised to revolutionize how patients can control these advanced prostheses using their thoughts alone. For patients with spinal cord injury or stroke, functional electrical stimulation promises to provide the most sophisticated prosthetic limbs possible by reanimating paralyzed arms of these patients. Advances in technology and robotics continue to help patients recover vital function. This article examines the latest neurorestorative technologies for patients who have either undergone amputation or lost the use of their upper extremities secondary to stroke or spinal cord injury.

  19. Patient-specific prosthetic fingers by remote collaboration--a case study.

    Directory of Open Access Journals (Sweden)

    John-John Cabibihan

    Full Text Available The concealment of amputation through prosthesis usage can shield an amputee from social stigma and help improve the emotional healing process especially at the early stages of hand or finger loss. However, the traditional techniques in prosthesis fabrication defy this as the patients need numerous visits to the clinics for measurements, fitting and follow-ups. This paper presents a method for constructing a prosthetic finger through online collaboration with the designer. The main input from the amputee comes from the Computer Tomography (CT data in the region of the affected and the non-affected fingers. These data are sent over the internet and the prosthesis is constructed using visualization, computer-aided design and manufacturing tools. The finished product is then shipped to the patient. A case study with a single patient having an amputated ring finger at the proximal interphalangeal joint shows that the proposed method has a potential to address the patient's psychosocial concerns and minimize the exposure of the finger loss to the public.

  20. Late Prosthetic Shoulder Hemiarthroplasty after Failed Management of Complex Proximal Humeral Fractures

    Directory of Open Access Journals (Sweden)

    A. Panagopoulos

    2013-01-01

    Full Text Available Background. The purpose of this study was to report our experience with shoulder hemiarthroplasty in the context of old trauma. Methods. 33 patients with failed treatment for a complex proximal humeral fracture underwent prosthetic hemiarthroplasty. There were 15 men and 18 women with a mean age of 58.1 years. The average period from initial treatment was 14.9 months. Sequelae included 11 malunions, 4 nonunions, 15 cases with avascular necrosis (AVN and 3 neglected posterior locked dislocations. Follow up investigation included radiological assessment and clinical evaluation using the Constant score and a visual analogue pain scale. Results. After a mean follow up of 82.5 months the median Constant score was 75.7 points, improved by 60% in comparison to preoperative values. Greater tuberosity displacement, large cuff tears and severe malunion were the factors most affected outcome. No cases of stem loosening or severe migration were noted. 60% of the patients were able to do activities up to shoulder level compared with 24% before reconstruction. Conclusions. Late shoulder hemiarthroplasty is technically difficult and the results are inferior to those reported for acute humeral head replacement, nonetheless remains a satisfactory reconstructive option when primary treatment fails.

  1. Increased resting-state functional connectivity of visual- and cognitive-control brain networks after training in children with reading difficulties

    Directory of Open Access Journals (Sweden)

    Tzipi Horowitz-Kraus

    2015-01-01

    Full Text Available The Reading Acceleration Program, a computerized reading-training program, increases activation in neural circuits related to reading. We examined the effect of the training on the functional connectivity between independent components related to visual processing, executive functions, attention, memory, and language during rest after the training. Children 8–12 years old with reading difficulties and typical readers participated in the study. Behavioral testing and functional magnetic resonance imaging were performed before and after the training. Imaging data were analyzed using an independent component analysis approach. After training, both reading groups showed increased single-word contextual reading and reading comprehension scores. Greater positive correlations between the visual-processing component and the executive functions, attention, memory, or language components were found after training in children with reading difficulties. Training-related increases in connectivity between the visual and attention components and between the visual and executive function components were positively correlated with increased word reading and reading comprehension, respectively. Our findings suggest that the effect of the Reading Acceleration Program on basic cognitive domains can be detected even in the absence of an ongoing reading task.

  2. Beery-Buktenica Developmental Test of Visual-Motor Integration Performance in Children with Traumatic Brain Injury and Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Sutton, Griffin P.; Barchard, Kimberly A.; Bello, Danielle T.; Thaler, Nicholas S.; Ringdahl, Erik; Mayfield, Joan; Allen, Daniel N.

    2011-01-01

    Evaluation of visuoconstructional abilities is a common part of clinical neuropsychological assessment, and the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI; K. E. Beery & N. A. Beery, 2004) is often used for this purpose. However, few studies have examined its psychometric properties when used to assess children and…

  3. Prosthetic joint infections: radionuclide state-of-the-art imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gemmel, Filip [AZ Alma Campus Sijsele, Department of Nuclear Medicine, Sijsele-Damme (Belgium); Wyngaert, Hans van den [AZ Alma Campus Sijsele, Department of Orthopaedic Surgery, Sijsele-Damme (Belgium); Love, Charito [Albert Einstein College of Medicine of Yeshiva University, Division of Nuclear Medicine and Radiology, Bronx, NY (United States); Welling, M.M. [Leiden University Medical Center, Scientist Molecular Imaging, Department of Radiology, Section of Nuclear Medicine C2-203, Leiden (Netherlands); Gemmel, Paul [Ghent University, The Faculty of Economics and Business Administration, Ghent (Belgium); Palestro, Christopher J. [Hofstra North Shore-Long Island Jewish Health System, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Hempstead, NY (United States)

    2012-05-15

    Prosthetic joint replacement surgery is performed with increasing frequency. Overall the incidence of prosthetic joint infection (PJI) and subsequently prosthesis revision failure is estimated to be between 1 and 3%. Differentiating infection from aseptic mechanical loosening, which is the most common cause of prosthetic failure, is especially important because of different types of therapeutic management. Despite a thorough patient history, physical examination, multiple diagnostic tests and complex algorithms, differentiating PJI from aseptic loosening remains challenging. Among imaging modalities, radiographs are neither sensitive nor specific and cross-sectional imaging techniques, such as computed tomography and magnetic resonance imaging, are limited by hardware-induced artefacts. Radionuclide imaging reflects functional rather than anatomical changes and is not hampered by the presence of a metallic joint prosthesis. As a result scintigraphy is currently the modality of choice in the investigation of suspected PJI. Unfortunately, there is no true consensus about the gold standard technique since there are several drawbacks and limitations inherent to each modality. Bone scintigraphy (BS) is sensitive for identifying the failed joint replacement, but cannot differentiate between infection and aseptic loosening. Combined bone/gallium scintigraphy (BS/GS) offers modest improvement over BS alone for diagnosing PJI. However, due to a number of drawbacks, BS/GS has generally been superseded by other techniques but it still may have a role in neutropenic patients. Radiolabelled leucocyte scintigraphy remains the gold standard technique for diagnosing neutrophil-mediated processes. It seems to be that combined in vitro labelled leucocyte/bone marrow scintigraphy (LS/BMS), with an accuracy of about 90%, is currently the imaging modality of choice for diagnosing PJI. There are, however, significant limitations using in vitro labelled leucocytes and considerable effort

  4. Do we choose what we look at or it's our brain that chooses? : A cognitive approach to the relation between visual attention and perception based on advertising stimuli

    OpenAIRE

    Astals Serés, Anna; Añaños, Elena

    2011-01-01

    This study questions whether, when talking about graphical stimuli (and in particular, advertisements), attention is above the surface of consciousness that leads to a voluntary perception of the existing stimuli; or if attention is an involuntary process so that we perceive a selection of the stimuli our brain has previously chosen. Previous research of Cognitive Psychology based on advertising attention and perception documents that our cognitive response directly depends on the level of at...

  5. T1 weighted Brain Images at 7 Tesla Unbiased for Proton Density, T2* contrast and RF Coil Receive B1 Sensitivity with Simultaneous Vessel Visualization

    OpenAIRE

    Van de Moortele, Pierre-François; Auerbach, Edwards J.; Olman, Cheryl; Yacoub, Essa; Uğurbil, Kâmil; Moeller, Steen

    2009-01-01

    At high magnetic field, MR images exhibit large, undesirable signal intensity variations commonly referred to as “intensity field bias”. Such inhomogeneities mostly originate from heterogeneous RF coil B1 profiles and, with no appropriate correction, are further pronounced when utilizing rooted sum of square reconstruction with receive coil arrays. These artifacts can significantly alter whole brain high resolution T1-weighted (T1w) images that are extensively utilized for clinical diagnosis,...

  6. Impact testing of the residual limb: System response to changes in prosthetic stiffness

    Directory of Open Access Journals (Sweden)

    Erin Boutwell, PhD

    2016-04-01

    Full Text Available Currently, it is unknown whether changing prosthetic limb stiffness affects total limb stiffness and/or influences the shock absorption of an individual with transtibial amputation. The hypotheses tested within this study are that a decrease in longitudinal prosthetic stiffness will produce (1 reduced total limb stiffness and (2 reduced magnitude of peak impact forces and increased time delay to peak force. Fourteen subjects with a transtibial amputation participated in this study. Prosthetic stiffness was modified by means of a shock-absorbing pylon that provides reduced longitudinal stiffness through compression of a helical spring within the pylon. A sudden loading evaluation device was built to examine changes in limb loading mechanics during a sudden impact event. No significant change was found in the peak force magnitude or timing of the peak force between prosthetic limb stiffness conditions. Total limb stiffness estimates ranged from 14.9 to 17.9 kN/m but were not significantly different between conditions. Thus, the prosthetic-side total limb stiffness was unaffected by changes in prosthetic limb stiffness. The insensitivity of the total limb stiffness to prosthetic stiffness may be explained by the mechanical characteristics (i.e., stiffness and damping of the anatomical tissue within the residual limb.

  7. Effects of prosthetic foot forefoot flexibility on gait of unilateral transtibial prosthesis users

    Directory of Open Access Journals (Sweden)

    Elizabeth Klodd, MS

    2010-12-01

    Full Text Available Five solid-ankle experimental prosthetic feet were used in this double-blind randomized crossover study to determine the effects of forefoot flexibility on gait of 14 unilateral transtibial prosthesis users. Flexibility in experimental feet was altered by changing the number of flexural hinges in their forefoot sections. When experimental prosthetic foot conditions were compared, measured prosthetic ankle dorsiflexion range of motion increased as much as 3.3° with increasing flexibility (p < 0.001 and the foot's anterior moment arm (measured as the effective foot length ratio increased as much as 23% of the foot length with decreasing flexibility (p < 0.001. Subjects also showed increases in the difference between sound and prosthetic ankle moments as high as 0.53 Nm/kg in late stance phase of walking as flexibility decreased (p < 0.001. The difference between first peaks of the vertical ground reaction forces on the sound and prosthetic sides increased as much as 9% of body weight when subjects used the foot with the greatest flexibility (p = 0.001. The results of this study suggest solid-ankle prosthetic foot designs with overly flexible forefoot sections can cause a "drop-off" effect in late stance phase and during the transition of loading between prosthetic and contralateral limbs.

  8. Neural Anatomy of Primary Visual Cortex Limits Visual Working Memory.

    Science.gov (United States)

    Bergmann, Johanna; Genç, Erhan; Kohler, Axel; Singer, Wolf; Pearson, Joel

    2016-01-01

    Despite the immense processing power of the human brain, working memory storage is severely limited, and the neuroanatomical basis of these limitations has remained elusive. Here, we show that the stable storage limits of visual working memory for over 9 s are bound by the precise gray matter volume of primary visual cortex (V1), defined by fMRI retinotopic mapping. Individuals with a bigger V1 tended to have greater visual working memory storage. This relationship was present independently for both surface size and thickness of V1 but absent in V2, V3 and for non-visual working memory measures. Additional whole-brain analyses confirmed the specificity of the relationship to V1. Our findings indicate that the size of primary visual cortex plays a critical role in limiting what we can hold in mind, acting like a gatekeeper in constraining the richness of working mental function. PMID:25100854

  9. 基于稳态视觉诱发电位的脑-机接口研究%An Research on Brain-computer Interfaces Based on the Steady State Visual Evoked Potentials

    Institute of Scientific and Technical Information of China (English)

    郑军

    2011-01-01

    A Steady-State Visual Evoked Potentials ( SSVEP) based Brain-Computer Interfaces system whose stimuli frequency produced by a Liquid Crystal Displays (LED) is achieved. In order to extract the Steady-State Visual Evoked Potentials(SSVEP) , the Fast Fourier Transform ( FFT) and the method based on Mallat wavelet and AR model to offline analysis of the electroencephalogram are used. Analysis results show that these two methods both can extract the SSVEP signal with a high accuracy , and the FFT is more suitable for the brain-computer interface system, so it achieves a online test of the SSVEPBCIs based on FFT.%实现了一个以液晶显示器(LED)产生刺激频率的稳态视觉诱发电位(SSVEP)脑-机接口系统(BCIs).为了从脑电中提取出稳态视觉诱发电位(SSVEP)信号,运用基于快速傅里叶变换(FFT)的方法和基于Mallat小波及AR模型分析法这两种处理方法对脑电信号进行离线分析.实验结果表明,用这两种方法提取SSVEP信号都可以达到很高的准确率;而基于FFT的方法更适用于脑-机接口系统.因此用基于FFT的方法完成了这个SSVEPBCIs的在线实验.

  10. The mechanism of HIT/DLR prosthetic hand

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A multi-sensory five-fingered prosthetic hand has been designed on the basis of underactuated mechanism and coupling principle. The hand is much similar to the adult hand. Three motors actuate the thumb, the index finger and the other three fingers each. The hand comprises 13 joints. Actuated by a motor, the thumb can move along a conic surface, which is superior in appearance. Driven by another motor with springs as transmission elements, the mid finger, ring finger and little finger can envelop objects with complex shape. The sensory system and the appearance design are introduced. It was verified by experiments that the hand has strong capacity of self adaptation and can accomplish accurate and powerful grasp for objects with complex shape.

  11. Prosthetic joint infection: state-of-the-art

    Directory of Open Access Journals (Sweden)

    Boris Sergeyevich Belov

    2013-01-01

    Full Text Available In current clinical practice, joint replacement is one of the progressive and permanently developed surgical treatments in patients with locomotor injury of any genesis. However, the upward trend in the number of replacements is inevitably accompanied by the rising number of patients with periprosthetic joint infection. The polymorphism of its clinical picture and the nonspecificity of diagnostic tests lead to a frequent delay in the diagnosis of prosthetic joint infection (PJI and thus late treatment. This paper gives an update on the etiology, epidemiology, clinical presentation, and diagnosis of PJI. Emphasis is laid on the value of a multimodal approach to PJI treatment Р a combination of surgery and etiotropic antibiotic therapy. The choice of a treatment modality is determined by patient status, comorbidity, and the magnitude and duration of the infectious process.

  12. Processing of prosthetic heart valve sounds for classification. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.; Jones, H.E.

    1994-04-01

    People with serious heart conditions have had their expected life span extended considerably with the development of the prosthetic heart valve especially with the great strides made in valve design. Even though the designs are extremely reliable, the valves are mechanical and operating continuously over a long period, therefore, structural failures can occur due to fatigue. Measuring heart sounds non-invasively in a noisy environment puts more demands on the signal processing to extract the desired signals from the noise. In this paper the authors discuss acoustical signal processing techniques developed to process noisy heart valve sounds measured by a sensitive, surface contact microphone and used for the eventual classification of the valve.

  13. Prosthetic Correction of Postenucleation Socket Syndrome: A Case Report.

    Science.gov (United States)

    Kamble, Vikas B

    2014-12-01

    Postenucleation socket syndrome is a frequent late complication of enucleation of eye globe. Several pathophysiological mechanisms have been proposed to account for the symptoms of postenucleation socket syndrome, which include lost orbital volume, superior sulcus deformity, upper eyelid ptosis, lower eyelid laxity, and backward tilt of the prosthesis. The goal of postenucleation socket syndrome treatment is to achieve the best possible functional and esthetic result. The treatment can be either conservative or surgical. For the patient interested in a non-surgical correction, the conservative treatment is simple and non invasive and can be done with prosthesis modification for good positioning, comfort, and mobility. This paper describes prosthetic correction of a patient with postenucleation socket syndrome by modified ocular prosthesis.

  14. Prosthetic management of a patient with Treacher Collins syndrome

    Directory of Open Access Journals (Sweden)

    Madhan R

    2006-01-01

    Full Text Available Treacher Collins syndrome encompasses a group of closely related defects of the head and neck. It is a rare syndrome characterized by bilaterally symmetrical abnormalities derived from the first and second brachial arches and the nasal placode. It is an autosomal dominant disorder and its occurence ranges from 1 in 25,000 to 1 in 50,000 live births. The facial appearance of these patients can be improved by either surgical or prosthetic rehabilitation. In this case report we are presenting the features of a 13-year-old boy with Treacher Collins syndrome. A multidisplinary approach was followed in managing the situation. The various treatment options and the steps involved in making an auricular prosthesis are also discussed.

  15. Prosthetic Joint Infections Due to Coagulase-Negative Staphylococci

    Directory of Open Access Journals (Sweden)

    Mohamad

    2015-12-01

    Full Text Available Context Staphylococcus aureus and coagulase-negative staphylococci (CoNS are the most frequently isolated pathogens and are responsible for approximately two-thirds of joint replacement infections. Evidence Acquisition Although both belong to the staphylococci genus, there are several epidemiological and therapeutic differences between S. aureus and the heterogenous group of CoNS. In general, however, preventive and therapeutic recommendations for Prosthetic Joint Infection PJI due to CoNS do not differ from PJI caused by other pathogens. Results The main differences between the pathogens lie in the clinical presentation of PJI, the presumed origin of infection, and the presence of a higher proportion of methicillin-resistant strains leading to a limited choice of antibiotic agents. Conclusions Fortunately, due to its lower virulence as compared to its cousin S. aureus, PJI due to CoNS may display higher remission rates than S. aureus-caused PJI after combined surgical and medical management.

  16. Prosthetic valve endocarditis after transcatheter aortic valve implantation

    DEFF Research Database (Denmark)

    Olsen, Niels Thue; De Backer, Ole; Thyregod, Hans G H;

    2015-01-01

    BACKGROUND: Transcatheter aortic valve implantation (TAVI) is an advancing mode of treatment for inoperable or high-risk patients with aortic stenosis. Prosthetic valve endocarditis (PVE) after TAVI is a serious complication, but only limited data exist on its incidence, outcome, and procedural...... risk factors. METHODS AND RESULTS: Observational single-center study of 509 consecutive patients treated with a transcatheter implanted self-expandable aortic valve prosthesis (Medtronic CoreValve). We identified 18 patients diagnosed with TAVI-PVE during a median follow-up period of 1.4 years......%) were treated conservatively and 1 with surgery. Four patients (22%) died from endocarditis or complications to treatment, 2 of those (11%) during initial hospitalization for PVE. An increased risk of TAVI-PVE was seen in patients with low implanted valve position (hazard ratio, 2.8 [1.1-7.2]), moderate...

  17. Patient-adapted treatment for prosthetic hip joint infection.

    Science.gov (United States)

    Baker, Richard P; Furustrand Tafin, Ulrika; Borens, Olivier

    2015-01-01

    Hip joint replacement is 1 of the most successful surgical procedures of the last century and the number of replacements implanted is steadily growing. An infected hip arthroplasty is a disaster, it leads to patient suffering, surgeon's frustration and significant costs to the health system. The treatment of an infected hip replacement is challenging, healing rates can be low, functional results poor with decreased patient satisfaction. However, if a patient-adapted treatment of infected hip joints is used a success rate of above 90% can be obtained.Patient-adapted treatment is based on 5 important concepts: teamwork; understanding the biofilm; diagnostic accuracy; correct definition and classification of PJI; and patient-tailored treatment.This review presents a patient-adapted treatment strategy to prosthetic hip infection. It incorporates the best aspects of the single and staged surgical strategies and promotes the short interval philosophy for the 2-stage approach. PMID:26044528

  18. Prosthetic heart valves: Objective Performance Criteria versus randomized clinical trial.

    Science.gov (United States)

    Grunkemeier, Gary L; Jin, Ruyun; Starr, Albert

    2006-09-01

    The current Food and Drug Administration (FDA) heart valve guidance document uses an objective performance criteria (OPC) methodology to evaluate the clinical performance of prosthetic heart valves. OPC are essentially historical controls, but they have turned out to be an adequate, and perhaps optimal, study design in this situation. Heart valves have a simple open-and-close mechanism, device effectiveness is easy to document, and the common complications (thromboembolism, thrombosis, bleeding, leak, and infection) are well known and easily detected. Thus, randomized clinical trials (RCTs) have not been deemed necessary for the regulatory approval of prosthetic heart valves. The OPC are derived from the average complication rates of all approved heart valves. Studies based on OPC have been shown to work well; many different valve models have gained FDA market approval based on this methodology. Although heart valve RCTs are not required by the FDA, they have been done to compare valves or treatment regimens after approval. Recently, the Artificial Valve Endocarditis Reduction Trial (AVERT) was designed to compare a new Silzone sewing ring, designed to reduce infection, with the Standard sewing ring on a St. Jude Medical heart valve. This was the largest heart valve RCT ever proposed (4,400 valve patients, followed for as long as 4 years), but it was stopped prematurely because of a high leak rate associated with the Silzone valve. Examining the results showed that a much smaller, OPC-based study with 800 patient-years would have been sufficient to disclose this complication of the Silzone valve. PMID:16928482

  19. Mycobacterium smegmatis infection of a prosthetic total knee arthroplasty.

    Science.gov (United States)

    Saffo, Zaid; Ognjan, Anthony

    2016-01-01

    The most common organisms causing prosthetic knee joint infections are staphylococci. However, arthroplasty infections with atypical microbial pathogens, such as Mycobacteria can occur. Due to the rarity of mycobacterial prosthetic joint infections, diagnosis, treatment, and management of these atypical infections represent a clinical challenge. A 71-year old female post-operative day 40 after a left total knee arthroplasty was hospitalized secondary to left knee pain and suspected arthroplasty infection. She had failed outpatient oral antimicrobial treatment for superficial stitch abscess; and outpatient IV/Oral antimicrobials for a clinical postoperative septic bursitis. Ultimately, resection arthroplasty with operative tissue acid fast bacterial cultures demonstrated growth of the Mycobacterium smegmatis group. Post-operatively, she completed a combination course of oral doxycycline and levofloxacin and successfully completed a replacement arthroplasty with clinical and microbial resolution of the infection. To our knowledge, literature review demonstrates three case of knee arthroplasty infection caused by the Mycobacterium smegmatis group. Correspondingly, optimal surgical procedures and antimicrobial management including antimicrobial selection, treatment duration are not well defined. Presently, the best treatment options consists of two step surgical management including prosthesis hardware removal followed by extended antimicrobial therapy, followed by consideration for re-implantation arthroplasty. Our case illustrates importance of considering atypical mycobacterial infections in post-operative arthroplasty infections not responding to traditional surgical manipulations and antimicrobials. For an arthroplasty infection involving the atypical Mycobacterium smegmatis group, two step arthroplasty revision, including arthroplasty resection, with a combination of oral doxycycline and levofloxacin can lead to successful infection resolution, allowing for a

  20. Aerogel Use as a Skin Protective Liner In Space Suits and Prosthetic Limbs Project

    Science.gov (United States)

    Roberson, Luke Bennett

    2014-01-01

    Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications for use in space suits and orthopedics. Three tests were performed on several types of aerogel to assess the properties of each material, and our initial findings demonstrated that these materrials would be excellent candidates for liner applications for prosthetics and space suits. The project is currently on hold until additional funding is obtained for application testing at the VH Hospitals in Tampa

  1. Simulation Techniques and Prosthetic Approach Towards Biologically Efficient Artificial Sense Organs- An Overview

    CERN Document Server

    Neogi, Biswarup; Mukherjee, Soumyajit; Das, Achintya; Tibarewala, D N

    2011-01-01

    An overview of the applications of control theory to prosthetic sense organs including the senses of vision, taste and odor is being presented in this paper. Simulation aspect nowadays has been the centre of research in the field of prosthesis. There have been various successful applications of prosthetic organs, in case of natural biological organs dis-functioning patients. Simulation aspects and control modeling are indispensible for knowing system performance, and to generate an original approach of artificial organs. This overview focuses mainly on control techniques, by far a theoretical overview and fusion of artificial sense organs trying to mimic the efficacies of biologically active sensory organs. Keywords: virtual reality, prosthetic vision, artificial

  2. Visual agnosia.

    Science.gov (United States)

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes.

  3. Brain Basics

    Medline Plus

    Full Text Available ... News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  4. Brain Basics

    Science.gov (United States)

    ... News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  5. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... learning more about how the brain grows and works in healthy people, and how normal brain development ...

  6. Visual art and visual perception

    NARCIS (Netherlands)

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perception ‘Visual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their

  7. Spatial visualization ability and laparoscopic skills in novice learners: evaluating stereoscopic versus monoscopic visualizations.

    Science.gov (United States)

    Roach, Victoria A; Mistry, Manisha R; Wilson, Timothy D

    2014-01-01

    Elevated spatial visualization ability (Vz) is thought to influence surgical skill acquisition and performance. Current research suggests that stereo visualization technology and its association with skill performance may confer perceptual advantages. This is of particular interest in laparoscopic skill training, where stereo visualization may confer learning advantages to novices of variant Vz. This study explored laparoscopic skill performance scores in novices with variable spatial ability utilizing stereoscopic and traditional monoscopic visualization paradigms. Utilizing the McGill Inanimate System for Teaching and Evaluating Laparoscopic Skills (MISTELS) scoring protocol it was hypothesized that individuals with high spatial visualization ability (HVz) would achieve higher overall and individual MISTELS task scores as compared to low spatial visualization ability (LVz) counterparts. Further, we also hypothesized that a difference would exist between HVz and LVz individual scores based on the viewing modality employed. No significant difference was observed between HVz and LVz individuals for MISTELS tasks scores, overall or individually under both viewing modalities, despite higher average MISTELS scores for HVz individuals. The lack of difference between scores obtained under the stereo modality suggested that the additional depth that is conferred by the stereoscopic visualization may act to enhance performance for individuals with LVz, potentially equilibrating their performance with their HVz peers. Further experimentation is required to better ascertain the effects of stereo visualization in individuals of high and low Vz, though it appears stereoscopic visualizations could serve as a prosthetic to enhance skill performance.

  8. 76 FR 64429 - Advisory Committee on Prosthetics and Special-Disabilities Programs; Notice of Meeting

    Science.gov (United States)

    2011-10-18

    ... briefed by the Chief Disability and Medical Assessment Officer; Physical Therapy Program Specialist; Executive Director, Federal Recovery Coordination Program; Deputy Director, Recreation Therapy; Director, Amputation System of Care; and Deputy Chief Consultant, Prosthetics and Sensory Aids Service. On November...

  9. Immediate natural tooth pontic: A viable yet temporary prosthetic solution: A patient reported outcome

    Directory of Open Access Journals (Sweden)

    Sudhir Bhandari

    2012-01-01

    Conclusion: The concept of immediate pontic placement is surely a viable treatment option and promises an excellent transient esthetic solution for a lost tooth as well as enables good preparation of the extraction site for future prosthetic replacement.

  10. Catalytical Activities of Reconstructed Hemoglobin with Different Central Ions in Prosthetic Group

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-yu; SUN Bao-wei; LI Yuan-zong; CHANG Wen-bao

    2003-01-01

    Hemoglobin(Hb) was de-prosthetized, which was then reconstructed with the prosthetic groups with different central metal ions including Fe(Ⅲ), Co(Ⅱ) and Mn(Ⅱ). The spectral properties along with the catalase and peroxidase activities of the reconstructed hemoglobin were compared with those of Hb and prosthetic groups with different ions. When the central ion is iron, the reconstituted Hb(rHb) has the highest catalase and peroxidase activities. Maybe it is the reason that iron is chosen as the central ion in the prosthetic groups of natural hemoproteins. Different from peroxidase activity, the catalase activity of hemin cannot be enhanced by the microenvironment of apoHb. This result shows that the structure of apoHb is more similar to that of apoHRP than that of apocatalase.

  11. A Quality Function Deployment (QFD approach to designing a prosthetic myoelectric hand

    Directory of Open Access Journals (Sweden)

    Erika Sofía Olaya Escobar

    2010-04-01

    Full Text Available This paper presents a Quality Function Deployment (QFD model based on computing with words. It is specifically used in the House of Quality (HOQ construction phase. It illustrates the methodology employed in designing a prosthetic myoelectric hand.

  12. An experimental comparative study between polypropylene and laminated lower limb prosthetic socket

    Directory of Open Access Journals (Sweden)

    .Haider F. Neama, M.Sc

    2007-01-01

    Full Text Available Most researchers concentrate their studies on the design, stress and pressure distributions of the prosthetic socket. A little attention is considered for the stiffness of the various materials of the prosthetic sockets. Prosthetic laminated sockets in Iraq are costly to be manufactured while polypropylene socket is relatively cheap in comparing with the laminates. Experimental study is conducted to compare the stiffness of five prosthetic sockets made of different materials. Compression, three point flexural and tensile tests are implemented by the Testometric machine. The laminate sockets give better results in compression than polypropylene. Polypropylene gives good results in bending compared with the laminate sockets. When the socket loads are mainly in compression i.e. the low activity level patients, it seems that any of the tested sockets could be used, however, when the load will be not only in compression but in flexion as well i.e. high activity patients, socket No.1 and 5 could be used

  13. Finite element analysis of the contact interface between trans-femoral stump and prosthetic socket.

    Science.gov (United States)

    Zhang, Linlin; Zhu, Ming; Shen, Ling; Zheng, Feng

    2013-01-01

    Transfemoral amputees need prosthetic devices after amputation surgery, and the interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. The purpose of this study was to build a nonlinear finite element model to investigate the interface pressure between the above-knee residual limb and its prosthetic socket. The model was three-dimensional (3D) with consideration of nonlinear boundary conditions. Contact analysis was used to simulate the friction conditions between skin and the socket. The normal stresses up to 80.57 kPa at the distal end of the soft tissue. The longitudinal and circumferential shear stress distributions at the limb-socket interface were also simulated. This study explores the influences of load transfer between trans-femoral residual limb and its prosthetic socket.

  14. Prosthetic finger phalanges with lifelike skin compliance for low-force social touching interactions

    CERN Document Server

    Cabibihan, John-John; Ge, Shuzhi Sam; 10.1186/1743-0003-8-16

    2011-01-01

    Prosthetic arms and hands that can be controlled by the user's electromyography (EMG) signals are emerging. Eventually, these advanced prosthetic devices will be expected to touch and be touched by other people. As realistic as they may look, the currently available prosthetic hands have physical properties that are still far from the characteristics of human skins because they are much stiffer. In this paper, different configurations of synthetic finger phalanges have been investigated for their skin compliance behaviour and have been compared with the phalanges of the human fingers and a phalanx from a commercially available prosthetic hand. Handshake tests were performed to identify which areas on the human hand experience high contact forces. After these areas were determined, experiments were done on selected areas using an indenting probe to obtain the force-displacement curves. Finite element simulations were used to compare the force-displacement results of the synthetic finger phalanx designs with th...

  15. Prosthetic improvement of pronounced buccally positioned zygomatic implants: a clinical report.

    Science.gov (United States)

    Bacchi, Ataís; Santos, Mateus Bertolini Fernandes dos; Pimentel, Marcele Jardim; Nóbilo, Mauro Antonio de Arruda; Consani, Rafael Leonardo Xediek

    2014-08-01

    This report presents a prosthetic technique for the improvement of surgically positioned, buccally placed zygomatic implants with the use of custom abutments for improved retention screw position and an esthetic implant reconstruction. The patient presented four zygomatic implants with pronounced buccal inclination. The anterior implants were inclined toward the location where the anterior artificial teeth should be placed during rehabilitation. As the manufacturer does not provide angulated abutments, we attempted the waxing and overcasting of a prosthetic abutment, repositioning the access holes of the prosthetic screws to a more palatal position. This clinical report demonstrates that abutment customization could be an interesting way to relocate the access holes of the prosthetic screws in cases of zygomatic implants with pronounced buccal inclination.

  16. Advances for prosthetic technology from historical perspective to current status to future application

    CERN Document Server

    LeMoyne, Robert

    2016-01-01

    This book focuses on the advances in transtibial prosthetic technology and targets research in the evolution of the powered prosthesis such as the BiOM, which was derived from considerable research and development at the Massachusetts Institute of Technology. The concept of the book spans the historical evolution of prosthetic applications from passive to new and futuristic robotic prosthetic technologies.  The author describes the reasons for amputation, surgical procedures, and an historical perspective of the prosthesis for the lower limb. He also addresses the phases and sub-phases of gait and compensatory mechanisms arising for a transtibial prosthesis and links the compensatory mechanisms to long-term morbidities.  The general technologies for gait analysis central to prosthetic design and the inherent biomechanics foundations for analysis are also explored.  The book reports on recent-past to current-term applications with passive elastic prostheses.  The core of the book deals with futuristic robo...

  17. Simulation Techniques and Prosthetic Approach Towards Biologically Efficient Artificial Sense Organs- An Overview

    OpenAIRE

    Neogi, Biswarup; Ghosal, Soumya; Mukherjee, Soumyajit; Das, Achintya; D N TIBAREWALA

    2011-01-01

    An overview of the applications of control theory to prosthetic sense organs including the senses of vision, taste and odor is being presented in this paper. Simulation aspect nowadays has been the centre of research in the field of prosthesis. There have been various successful applications of prosthetic organs, in case of natural biological organs dis-functioning patients. Simulation aspects and control modeling are indispensible for knowing system performance, and to generate an original a...

  18. Fixed prosthetics over implant-tooth support – survival rate over 4 years of follow up

    OpenAIRE

    Nikolovski, Bruno; Cvetanovska-Stojchevska, Daniela; Bundalevska-Aleksandrovska, Ana; Minovska, Ana; Radojkova-Nikolovska, Vera

    2015-01-01

    Long – term survival rate of bridges over implants is the goal of the implant therapy. Often fixed bridges are supported by combination of natural teeth and implants. OBJECTIVE: Our goal is to check the survival rate of the prosthetics over combination of natural teeth and implants comparing to fixed prosthetics over natural teeth within 4 years of follow up. MATERIAL AND METHOD: The patients were divided into 2 groups. The implant group of 20 patients with 32 implants were pla...

  19. Management of recto-vaginal fistulas after prosthetic reinforcement treatment for pelvic organ prolapse

    Institute of Scientific and Technical Information of China (English)

    Mehdi; Ouassi; Silvia; Cresti; Urs; Giger; Igor; Sielezneff; Nicolas; Pirrò; Bruno; Berthet; Philippe; Grandval; Bernard; Consentino; Bernard; Sastre

    2010-01-01

    AIM: To communicate our findings on successful treat-ment of recto-vaginal fistulas (RVFs) after prosthetic reinforcement surgery of pelvic organ prolapse (POP). METHODS: A retrospective single center study between 1998 and 2008 was performed. A total of 80 patients with RVF were identified, of which five patients (6%), with a mean age of 65 years (range: 52-73), had undergone previous surgery for POP with pros-thetic reinforcement. RESULTS: All patients complained about ongoing vaginal infections and febri...

  20. 2-stage revision recommended for treatment of fungal hip and knee prosthetic joint infections

    OpenAIRE

    Kuiper, Jesse WP; van den Bekerom, Michel PJ; van der Stappen, Jurgen; Peter A. Nolte; Colen, Sascha

    2013-01-01

    Background and purpose Fungal prosthetic joint infections are rare and difficult to treat. This systematic review was conducted to determine outcome and to give treatment recommendations. Patients and methods After an extensive search of the literature, 164 patients treated for fungal hip or knee prosthetic joint infection (PJI) were reviewed. This included 8 patients from our own institutions. Results Most patients presented with pain (78%) and swelling (65%). In 68% of the patients, 1 or mo...