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neural prosthesis

Felix P Aplin, Erica L Fletcher, Chi D Luu, Kirstan A Vessey, Penelope J Allen, Robyn H Guymer, Robert K Shepherd, Mohit N Shivdasani
Purpose: Retinal prostheses have emerged as a promising technology to restore vision in patients with severe photoreceptor degeneration. To better understand how neural degeneration affects the efficacy of electronic implants, we investigated the function of a suprachoroidal retinal implant in a feline model. Methods: Unilateral retinal degeneration was induced in four adult felines by intravitreal injection of adenosine triphosphate (ATP). Twelve weeks post injection, animals received suprachoroidal electrode array implants in each eye, and responses to electrical stimulation were obtained using multiunit recordings from the visual cortex...
October 1, 2016: Investigative Ophthalmology & Visual Science
Clément Hébert, Myline Cottance, Julie Degardin, Emmanuel Scorsone, Lionel Rousseau, Gaelle Lissorgues, Philippe Bergonzo, Serge Picaud
Nanocrystalline Boron doped Diamond proved to be a very attractive material for neural interfacing, especially with the retina, where reduce glia growth is observed with respect to other materials, thus facilitating neuro-stimulation over long terms. In the present study, we integrated diamond microelectrodes on a polyimide substrate and investigated their performances for the development of neural prosthesis. A full description of the microfabrication of the implants is provided and their functionalities are assessed using cyclic voltammetry and electrochemical impedance spectroscopy...
December 1, 2016: Materials Science & Engineering. C, Materials for Biological Applications
Cosima Prahm, Korbinian Eckstein, Max Ortiz-Catalan, Georg Dorffner, Eugenijus Kaniusas, Oskar C Aszmann
BACKGROUND: Controlling a myoelectric prosthesis for upper limbs is increasingly challenging for the user as more electrodes and joints become available. Motion classification based on pattern recognition with a multi-electrode array allows multiple joints to be controlled simultaneously. Previous pattern recognition studies are difficult to compare, because individual research groups use their own data sets. To resolve this shortcoming and to facilitate comparisons, open access data sets were analysed using components of BioPatRec and Netlab pattern recognition models...
2016: BMC Research Notes
S Becker, M Diers
Many chronic pain syndromes are characterized by enhanced perception of painful stimuli as well as alterations in cortical processing in sensory and motor regions. In this review article the alterations in muscle pain and neuropathic pain are described. Alterations in patients with fibromyalgia and chronic back pain are described as examples for musculoskeletal pain and also in patients with phantom limb pain after amputation and complex regional pain syndrome as examples for neuropathic pain. In addition to altered pain perception, cumulative evidence on alterations in the processing of reward and the underlying mechanisms in chronic pain has been described...
October 2016: Der Schmerz
Na Lu, Tengfei Li, Xiaodong Ren, Hongyu Miao
Motor imagery classification is an important topic in brain computer interface (BCI) research that enables the recognition of a subject's intension to, e.g., implement prosthesis control. The brain dynamics of motor imagery are usually measured by electroencephalography (EEG) as nonstationary time series of low signal-to-noise ratio. Although a variety of methods have been previously developed to learn EEG signal features, the deep learning idea has rarely been explored to generate new representation of EEG features and achieve further performance improvement for motor imagery classification...
August 17, 2016: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Sohmyung Ha, Massoud L Khraiche, Abraham Akinin, Yi Jing, Samir Damle, Yanjin Kuang, Sue Bauchner, Yu-Hwa Lo, William R Freeman, Gabriel A Silva, Gert Cauwenberghs
OBJECTIVE: Despite considerable advances in retinal prostheses over the last two decades, the resolution of restored vision has remained severely limited, well below the 20/200 acuity threshold of blindness. Towards drastic improvements in spatial resolution, we present a scalable architecture for retinal prostheses in which each stimulation electrode is directly activated by incident light and powered by a common voltage pulse transferred over a single wireless inductive link. APPROACH: The hybrid optical addressability and electronic powering scheme provides separate spatial and temporal control over stimulation, and further provides optoelectronic gain for substantially lower light intensity thresholds than other optically addressed retinal prostheses using passive microphotodiode arrays...
October 2016: Journal of Neural Engineering
John S Choi, Austin J Brockmeier, David B McNiel, Lee M von Kraus, José C Príncipe, Joseph T Francis
OBJECTIVE: Lost sensations, such as touch, could one day be restored by electrical stimulation along the sensory neural pathways. Such stimulation, when informed by electronic sensors, could provide naturalistic cutaneous and proprioceptive feedback to the user. Perceptually, microstimulation of somatosensory brain regions produces localized, modality-specific sensations, and several spatiotemporal parameters have been studied for their discernibility. However, systematic methods for encoding a wide array of naturally occurring stimuli into biomimetic percepts via multi-channel microstimulation are lacking...
October 2016: Journal of Neural Engineering
Laura Williams, Nikta Pirouz, J C Mizelle, William Cusack, Rob Kistenberg, Lewis A Wheaton
OBJECTIVE: Upper extremity loss presents immediate and lasting challenges for motor control. While sensory and motor representations of the amputated limb undergo plasticity to adjacent areas of the sensorimotor homunculus, it remains unclear whether laterality of motor-related activity is affected by neural reorganization following amputation. METHODS: Using electroencephalography, we evaluated neural activation patterns of formerly right hand dominant persons with upper limb loss (amputees) performing a motor task with their residual right limb, then their sound left limb...
September 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Yue Wen, Jennie Si, Xiang Gao, Stephanie Huang, He Huang
This brief presents a novel application of adaptive dynamic programming (ADP) for optimal adaptive control of powered lower limb prostheses, a type of wearable robots to assist the motor function of the limb amputees. Current control of these robotic devices typically relies on finite state impedance control (FS-IC), which lacks adaptability to the user's physical condition. As a result, joint impedance settings are often customized manually and heuristically in clinics, which greatly hinder the wide use of these advanced medical devices...
July 11, 2016: IEEE Transactions on Neural Networks and Learning Systems
Taimoor Afzal, Kamran Iqbal, Gannon White, Andrew B Wright
Active lower limb transfemoral prostheses have enabled amputees to perform different locomotion modes such as walking, stair ascent, stair descent, ramp ascent and ramp descent. To achieve seamless mode transitions, these devices either rely on neural information from the amputee's residual limbs or sensors attached to the prosthesis to identify the intended locomotion modes or both. We present an approach for classification of locomotion modes based on the framework of muscle synergies underlying electromyography (EMG) signals...
June 28, 2016: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Jonathan C Kao, Paul Nuyujukian, Stephen I Ryu, Krishna V Shenoy
Communication neural prostheses aim to restore efficient communication to people with motor neurological injury or disease by decoding neural activity into control signals. These control signals are both analog (e.g., the velocity of a computer mouse) and discrete (e.g., clicking an icon with a computer mouse) in nature. Effective, high-performing, and intuitive-to-use communication prostheses should be capable of decoding both analog and discrete state variables seamlessly. However, to date, the highest-performing autonomous communication prostheses rely on precise analog decoding, and typically do not incorporate highperformance discrete decoding...
June 21, 2016: IEEE Transactions on Bio-medical Engineering
Thomas C Spencer, James B Fallon, Patrick C Thien, Mohit N Shivdasani
PURPOSE: The resolution provided by present state-of-the-art retinal prostheses is severely limiting for recipients, partly due to the broad spread of activation in the retina in response to monopolar (MP) electrical stimulation. Focused multipolar (FMP) stimulation has been shown to restrict neural activation in the cochlea compared to MP stimulation. We extended the FMP stimulation technique to a two-dimensional electrode array and compared its efficacy to MP and hexapolar (HP) stimulation in the retina...
June 1, 2016: Investigative Ophthalmology & Visual Science
Delisa T Lawson, William F Cusack, Regan Lawson, Ashley Hardy, Robert Kistenberg, Lewis A Wheaton
Prior work in amputees and partial limb immobilization have shown improved neural and behavioral outcomes in using their residual limb with prosthesis when undergoing observation-based training with a prosthesis-using actor compared to an intact limb. It was posited that these improvements are due to an alignment of user with the actor. It may be affected by visual angles that allow emphasis of critical joint actions which may promote behavioral changes. The purpose of this study was to examine how viewing perspective of observation-based training effects prosthesis adaptation in naïve device users...
September 2016: Journal of Motor Behavior
Sam A Deadwyler, Robert E Hampson, Dong Song, Ioan Opris, Greg A Gerhardt, Vasilis Z Marmarelis, Theodore W Berger
Very productive collaborative investigations characterized how multineuron hippocampal ensembles recorded in nonhuman primates (NHPs) encode short-term memory necessary for successful performance in a delayed match to sample (DMS) task and utilized that information to devise a unique nonlinear multi-input multi-output (MIMO) memory prosthesis device to enhance short-term memory in real-time during task performance. Investigations have characterized how the hippocampus in primate brain encodes information in a multi-item, rule-controlled, delayed match to sample (DMS) task...
May 24, 2016: Experimental Neurology
Tao Zhang, Tiejun Liu, Fali Li, Mengchen Li, Dongbo Liu, Rui Zhang, Hui He, Peiyang Li, Jinnan Gong, Cheng Luo, Dezhong Yao, Peng Xu
Motor imagery (MI)-based brain-computer interfaces (BCIs) have been widely used for rehabilitation of motor abilities and prosthesis control for patients with motor impairments. However, MI-BCI performance exhibits a wide variability across subjects, and the underlying neural mechanism remains unclear. Several studies have demonstrated that both the fronto-parietal attention network (FPAN) and MI are involved in high-level cognitive processes that are crucial for the control of BCIs. Therefore, we hypothesized that the FPAN may play an important role in MI-BCI performance...
July 1, 2016: NeuroImage
Anna Lisa Ciancio, Francesca Cordella, Roberto Barone, Rocco Antonio Romeo, Alberto Dellacasa Bellingegni, Rinaldo Sacchetti, Angelo Davalli, Giovanni Di Pino, Federico Ranieri, Vincenzo Di Lazzaro, Eugenio Guglielmelli, Loredana Zollo
This paper intends to provide a critical review of the literature on the technological issues on control and sensorization of hand prostheses interfacing with the Peripheral Nervous System (i.e., PNS), and their experimental validation on amputees. The study opens with an in-depth analysis of control solutions and sensorization features of research and commercially available prosthetic hands. Pros and cons of adopted technologies, signal processing techniques and motion control solutions are investigated. Special emphasis is then dedicated to the recent studies on the restoration of tactile perception in amputees through neural interfaces...
2016: Frontiers in Neuroscience
Vinícius Rosa Cota, Bruna Marcela Bacellar Drabowski, Jasiara Carla de Oliveira, Márcio Flávio Dutra Moraes
Many patients with epilepsy do not obtain proper control of their seizures through conventional treatment. We review aspects of the pathophysiology underlying epileptic phenomena, with a special interest in the role of the amygdala, stressing the importance of hypersynchronism in both ictogenesis and epileptogenesis. We then review experimental studies on electrical stimulation of mesiotemporal epileptogenic areas, the amygdala included, as a means to treat medically refractory epilepsy. Regular high-frequency stimulation (HFS) commonly has anticonvulsant effects and sparse antiepileptogenic properties...
June 2016: Journal of Neuroscience Research
Shufeng Li, Bradley Tuft, Linjing Xu, Marc Polacco, Joseph C Clarke, C Allan Guymon, Marlan R Hansen
Micro- and nanoscale surface features have emerged as potential tools to direct neurite growth into close proximity with next generation neural prosthesis electrodes. However, the signaling events underlying the ability of growth cones to respond to topographical features remain largely unknown. Accordingly, this study probes the influence of [Ca(2+) ]i and cyclic nucleotide levels on the ability of neurites from spiral ganglion neurons (SGNs) to precisely track topographical micropatterns. Photopolymerization and photomasking were used to generate micropatterned methacrylate polymer substrates...
August 2016: Journal of Biomedical Materials Research. Part A
Caterina Carboni, Lorenzo Bisoni, Nicola Carta, Roberto Puddu, Stanisa Raspopovic, Xavier Navarro, Luigi Raffo, Massimo Barbaro
The prototype of an electronic bi-directional interface between the Peripheral Nervous System (PNS) and a neuro-controlled hand prosthesis is presented. The system is composed of 2 integrated circuits: a standard CMOS device for neural recording and a HVCMOS device for neural stimulation. The integrated circuits have been realized in 2 different 0.35μ m CMOS processes available from ams. The complete system incorporates 8 channels each including the analog front-end, the A/D conversion, based on a sigma delta architecture and a programmable stimulation module implemented as a 5-bit current DAC; two voltage boosters supply the output stimulation stage with a programmable voltage scalable up to 17V...
April 2016: Biomedical Microdevices
Carolina Migliorelli, Joan F Alonso, Sergio Romero, Miguel A Mañanas, Rafał Nowak, Antonio Russi
OBJECTIVE: Medical intractable epilepsy is a common condition that affects 40% of epileptic patients that generally have to undergo resective surgery. Magnetoencephalography (MEG) has been increasingly used to identify the epileptogenic foci through equivalent current dipole (ECD) modeling, one of the most accepted methods to obtain an accurate localization of interictal epileptiform discharges (IEDs). Modeling requires that MEG signals are adequately preprocessed to reduce interferences, a task that has been greatly improved by the use of blind source separation (BSS) methods...
April 2016: Journal of Neural Engineering
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