The Experts below are selected from a list of 2556 Experts worldwide ranked by ideXlab platform
Dustin J. Tyler - One of the best experts on this subject based on the ideXlab platform.
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Chronic Nerve health following implantation of femoral Nerve Cuff electrodes.
Journal of neuroengineering and rehabilitation, 2020Co-Authors: Max J. Freeberg, Gilles Pinault, Ronald J Triolo, Dustin J. Tyler, Rahila AnsariAbstract:BACKGROUND Peripheral Nerve stimulation with implanted Nerve Cuff electrodes can restore standing, stepping and other functions to individuals with spinal cord injury (SCI). We performed the first study to evaluate the clinical electrodiagnostic changes due to electrode implantation acutely, chronic presence on the Nerve peri- and post-operatively, and long-term delivery of electrical stimulation. METHODS A man with bilateral lower extremity paralysis secondary to cervical SCI sustained 5 years prior to enrollment received an implanted standing neuroprosthesis including composite flat interface Nerve electrodes (C-FINEs) electrodes implanted around the proximal femoral Nerves near the inguinal ligaments. Electromyography quantified neurophysiology preoperatively, intraoperatively, and through 1 year postoperatively. Stimulation charge thresholds, evoked knee extension moments, and weight distribution during standing quantified neuroprosthesis function over the same interval. RESULTS Femoral compound motor unit action potentials increased 31% in amplitude and 34% in area while evoked knee extension moments increased significantly (p
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Selective Nerve Cuff Stimulation Strategies for Prolonging Muscle Output
IEEE transactions on bio-medical engineering, 2019Co-Authors: Kristen T. Gelenitis, Ronald J Triolo, Brian M. Sanner, Dustin J. TylerAbstract:Neural stimulation systems are often limited by rapid muscle fatigue. Selective Nerve Cuff electrodes can target independent yet synergistic motor unit pools (MUPs), which can be used in duty-cycle reducing stimulation paradigms to prolong joint moment output. Objective: This study investigates waveform parameters within moment-prolonging paradigms and determines strategies for their optimal implementation. Methods: Composite flat-interface Nerve Cuff electrodes (C-FINEs) were chronically implanted on feline proximal sciatic Nerves. Cyclic stimulation tests determined effects of stimulation period and duty cycle in different MUP types. Ideal parameters were then used in duty-cycle reducing carousel stimulation. Time to 50% reduction in moment (T50), moment overshoot, and moment ripple were determined for constant, open-loop carousel, and moment feedback-controlled closed-loop carousel stimulation. Results: A stimulation period of 1 s best maintained joint moment for all MUPs. Low (25%) duty cycles consistently improved joint moment maintenance, though allowable duty cycle varied among MUPs by gross muscle and fiber type. Both open- and closed-loop carousel stimulation significantly increased T50 over constant stimulation. Closed-loop carousel significantly decreased moment overshoot over the other conditions, and significantly decreased moment ripple compared with open-loop stimulation. Conclusion: Selectivity-enabled carousel stimulation prolongs joint moment over conventional constant stimulation. Appropriate waveform parameters can be quickly determined for individual MUPs and stimulation can be controlled for additional performance improvements with this paradigm. Significance: Providing prolonged, stable joint moment and muscle output to recipients of motor neuroprostheses will improve clinical outcomes, increase independence, and positively impact quality of life.
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Chronic Nerve Health Following Implantation of Nerve Cuff Electrodes Designed for the Proximal Femoral Nerve (S37.001)
Neurology, 2018Co-Authors: Max J. Freeberg, Gilles Pinault, Ronald J Triolo, Dustin J. Tyler, Rahila AnsariAbstract:Objective: This is the first in-human, year-long study to quantify the electrodiagnostic consequences in Nerve physiology following implantation of a novel Nerve Cuff electrode (NCE) implanted around the proximal femoral Nerves, near the inguinal ligament. Background: Peripheral Nerve stimulation with implanted NCEs can modulate the motor, sensory, and autonomic nervous system. Following spinal cord injury, these electrodes can restore standing and stepping function to paraplegic patients. However, there is an absence of clinical data evaluating the chronic impact of NCEs on Nerve health in human subjects. Design/Methods: We previously designed directionally-flexible NCEs to accommodate Nerve bending and provide gentle Nerve reshaping for improved selectivity of fascicular stimulation. Successful animal testing permitted implantation on bilateral femoral Nerves, proximal to the branch innervating the sartorius muscle. They were deployed as part of a standing neuroprosthesis in a man with bilateral lower extremity paralysis secondary to long-standing cervical spinal cord injury. Electromyography quantified neurophysiology preoperatively through 1-year postoperatively. Stimulation charge thresholds and evoked knee extension moments quantified neuroprosthesis function. Results: Femoral compound motor unit action potentials increased by 31% in amplitude and 34% in area, while evoked knee extension moments increased significantly (p Conclusions: This is the first human trial reporting acute and chronic neurophysiologic changes following implantation of and stimulation through NCEs. Electrodiagnostics indicated preserved Nerve health with increased motor responses following exercise. Temporary electrodiagnostic changes suggest minor Nerve irritation perioperatively. Functional results indicated that these NCEs recruited muscles selectively and stabilized function quickly. These year-long outcomes demonstrate the ability to safely implant NCEs near joints. Study Supported by: This research was funded by R01-EB001889 from the National Institute of Biomedical Imaging and Bioengineering of the NIH and by I01-RX001039 from the US Department of Veterans Affairs. This research was supported by NIH training grants T32- EB004314, T32- GM007250, and TL1- TR000441 and with resources provided by the Advanced Platform Technology (APT) Center of Excellence of the Louis Stokes Cleveland VA Medical Center, which is supported by NIH grant I50-RX001871. Disclosure: Dr. Freeberg has nothing to disclose. Dr. Pinault has nothing to disclose. Dr. Tyler has nothing to disclose. Dr. Triolo has nothing to disclose. Dr. Ansari has nothing to disclose.
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“Long-term stability of stimulating spiral Nerve Cuff electrodes on human peripheral Nerves”
Journal of neuroengineering and rehabilitation, 2017Co-Authors: Breanne P. Christie, Gilles Pinault, Dustin J. Tyler, Harry A. Hoyen, Max J. Freeberg, William D. Memberg, Ronald J TrioloAbstract:Electrical stimulation of the peripheral Nerves has been shown to be effective in restoring sensory and motor functions in the lower and upper extremities. This neural stimulation can be applied via non-penetrating spiral Nerve Cuff electrodes, though minimal information has been published regarding their long-term performance for multiple years after implantation. Since 2005, 14 human volunteers with cervical or thoracic spinal cord injuries, or upper limb amputation, were chronically implanted with a total of 50 spiral Nerve Cuff electrodes on 10 different Nerves (mean time post-implant 6.7 ± 3.1 years). The primary outcome measures utilized in this study were muscle recruitment curves, charge thresholds, and percent overlap of recruited motor unit populations. In the eight recipients still actively involved in research studies, 44/45 of the spiral contacts were still functional. In four participants regularly studied over the course of 1 month to 10.4 years, the charge thresholds of the majority of individual contacts remained stable over time. The four participants with spiral Cuffs on their femoral Nerves were all able to generate sufficient moment to keep the knees locked during standing after 2–4.5 years. The dorsiflexion moment produced by all four fibular Nerve Cuffs in the active participants exceeded the value required to prevent foot drop, but no tibial Nerve Cuffs were able to meet the plantarflexion moment that occurs during push-off at a normal walking speed. The selectivity of two multi-contact spiral Cuffs was examined and both were still highly selective for different motor unit populations for up to 6.3 years after implantation. The spiral Nerve Cuffs examined remain functional in motor and sensory neuroprostheses for 2–11 years after implantation. They exhibit stable charge thresholds, clinically relevant recruitment properties, and functional muscle selectivity. Non-penetrating spiral Nerve Cuff electrodes appear to be a suitable option for long-term clinical use on human peripheral Nerves in implanted neuroprostheses.
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EMBC - Optimizing Nerve Cuff stimulation of targeted regions through use of genetic algorithms
Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2011Co-Authors: Natalie Brill, Dustin J. TylerAbstract:A Nerve Cuff electrode is a viable technology for use in a neuroprostheses system to restore loss of function due to neurological injury. The Flat Interface Nerve Electrode (FINE) is a Nerve Cuff that gently reshapes the Nerve to bring the axons closer to the stimulating contacts. The overall goal of this work is to optimize Nerve Cuff stimulation in upper extremity Nerves. Recently, highly efficient and accurate linear models of neuronal activation have been developed in our lab. Using the fast calculations from the newly developed linear activation method, Nerve stimulation parameters such as current pulse width and pulse amplitude at many electrode contacts can be explored by employing optimization algorithms. Finite element Nerve models with high density electrodes were constructed based on upper extremity cadaveric Nerve cross sections. An objective function was developed to target specific groups of Nerve fascicles and minimize overlap amongst these groups. By changing the objective function and using a genetic search algorithm, stimulation parameters can be optimized for many contacts.
Ronald J Triolo - One of the best experts on this subject based on the ideXlab platform.
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Chronic Nerve health following implantation of femoral Nerve Cuff electrodes.
Journal of neuroengineering and rehabilitation, 2020Co-Authors: Max J. Freeberg, Gilles Pinault, Ronald J Triolo, Dustin J. Tyler, Rahila AnsariAbstract:BACKGROUND Peripheral Nerve stimulation with implanted Nerve Cuff electrodes can restore standing, stepping and other functions to individuals with spinal cord injury (SCI). We performed the first study to evaluate the clinical electrodiagnostic changes due to electrode implantation acutely, chronic presence on the Nerve peri- and post-operatively, and long-term delivery of electrical stimulation. METHODS A man with bilateral lower extremity paralysis secondary to cervical SCI sustained 5 years prior to enrollment received an implanted standing neuroprosthesis including composite flat interface Nerve electrodes (C-FINEs) electrodes implanted around the proximal femoral Nerves near the inguinal ligaments. Electromyography quantified neurophysiology preoperatively, intraoperatively, and through 1 year postoperatively. Stimulation charge thresholds, evoked knee extension moments, and weight distribution during standing quantified neuroprosthesis function over the same interval. RESULTS Femoral compound motor unit action potentials increased 31% in amplitude and 34% in area while evoked knee extension moments increased significantly (p
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Selective Nerve Cuff Stimulation Strategies for Prolonging Muscle Output
IEEE transactions on bio-medical engineering, 2019Co-Authors: Kristen T. Gelenitis, Ronald J Triolo, Brian M. Sanner, Dustin J. TylerAbstract:Neural stimulation systems are often limited by rapid muscle fatigue. Selective Nerve Cuff electrodes can target independent yet synergistic motor unit pools (MUPs), which can be used in duty-cycle reducing stimulation paradigms to prolong joint moment output. Objective: This study investigates waveform parameters within moment-prolonging paradigms and determines strategies for their optimal implementation. Methods: Composite flat-interface Nerve Cuff electrodes (C-FINEs) were chronically implanted on feline proximal sciatic Nerves. Cyclic stimulation tests determined effects of stimulation period and duty cycle in different MUP types. Ideal parameters were then used in duty-cycle reducing carousel stimulation. Time to 50% reduction in moment (T50), moment overshoot, and moment ripple were determined for constant, open-loop carousel, and moment feedback-controlled closed-loop carousel stimulation. Results: A stimulation period of 1 s best maintained joint moment for all MUPs. Low (25%) duty cycles consistently improved joint moment maintenance, though allowable duty cycle varied among MUPs by gross muscle and fiber type. Both open- and closed-loop carousel stimulation significantly increased T50 over constant stimulation. Closed-loop carousel significantly decreased moment overshoot over the other conditions, and significantly decreased moment ripple compared with open-loop stimulation. Conclusion: Selectivity-enabled carousel stimulation prolongs joint moment over conventional constant stimulation. Appropriate waveform parameters can be quickly determined for individual MUPs and stimulation can be controlled for additional performance improvements with this paradigm. Significance: Providing prolonged, stable joint moment and muscle output to recipients of motor neuroprostheses will improve clinical outcomes, increase independence, and positively impact quality of life.
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Chronic Nerve Health Following Implantation of Nerve Cuff Electrodes Designed for the Proximal Femoral Nerve (S37.001)
Neurology, 2018Co-Authors: Max J. Freeberg, Gilles Pinault, Ronald J Triolo, Dustin J. Tyler, Rahila AnsariAbstract:Objective: This is the first in-human, year-long study to quantify the electrodiagnostic consequences in Nerve physiology following implantation of a novel Nerve Cuff electrode (NCE) implanted around the proximal femoral Nerves, near the inguinal ligament. Background: Peripheral Nerve stimulation with implanted NCEs can modulate the motor, sensory, and autonomic nervous system. Following spinal cord injury, these electrodes can restore standing and stepping function to paraplegic patients. However, there is an absence of clinical data evaluating the chronic impact of NCEs on Nerve health in human subjects. Design/Methods: We previously designed directionally-flexible NCEs to accommodate Nerve bending and provide gentle Nerve reshaping for improved selectivity of fascicular stimulation. Successful animal testing permitted implantation on bilateral femoral Nerves, proximal to the branch innervating the sartorius muscle. They were deployed as part of a standing neuroprosthesis in a man with bilateral lower extremity paralysis secondary to long-standing cervical spinal cord injury. Electromyography quantified neurophysiology preoperatively through 1-year postoperatively. Stimulation charge thresholds and evoked knee extension moments quantified neuroprosthesis function. Results: Femoral compound motor unit action potentials increased by 31% in amplitude and 34% in area, while evoked knee extension moments increased significantly (p Conclusions: This is the first human trial reporting acute and chronic neurophysiologic changes following implantation of and stimulation through NCEs. Electrodiagnostics indicated preserved Nerve health with increased motor responses following exercise. Temporary electrodiagnostic changes suggest minor Nerve irritation perioperatively. Functional results indicated that these NCEs recruited muscles selectively and stabilized function quickly. These year-long outcomes demonstrate the ability to safely implant NCEs near joints. Study Supported by: This research was funded by R01-EB001889 from the National Institute of Biomedical Imaging and Bioengineering of the NIH and by I01-RX001039 from the US Department of Veterans Affairs. This research was supported by NIH training grants T32- EB004314, T32- GM007250, and TL1- TR000441 and with resources provided by the Advanced Platform Technology (APT) Center of Excellence of the Louis Stokes Cleveland VA Medical Center, which is supported by NIH grant I50-RX001871. Disclosure: Dr. Freeberg has nothing to disclose. Dr. Pinault has nothing to disclose. Dr. Tyler has nothing to disclose. Dr. Triolo has nothing to disclose. Dr. Ansari has nothing to disclose.
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“Long-term stability of stimulating spiral Nerve Cuff electrodes on human peripheral Nerves”
Journal of neuroengineering and rehabilitation, 2017Co-Authors: Breanne P. Christie, Gilles Pinault, Dustin J. Tyler, Harry A. Hoyen, Max J. Freeberg, William D. Memberg, Ronald J TrioloAbstract:Electrical stimulation of the peripheral Nerves has been shown to be effective in restoring sensory and motor functions in the lower and upper extremities. This neural stimulation can be applied via non-penetrating spiral Nerve Cuff electrodes, though minimal information has been published regarding their long-term performance for multiple years after implantation. Since 2005, 14 human volunteers with cervical or thoracic spinal cord injuries, or upper limb amputation, were chronically implanted with a total of 50 spiral Nerve Cuff electrodes on 10 different Nerves (mean time post-implant 6.7 ± 3.1 years). The primary outcome measures utilized in this study were muscle recruitment curves, charge thresholds, and percent overlap of recruited motor unit populations. In the eight recipients still actively involved in research studies, 44/45 of the spiral contacts were still functional. In four participants regularly studied over the course of 1 month to 10.4 years, the charge thresholds of the majority of individual contacts remained stable over time. The four participants with spiral Cuffs on their femoral Nerves were all able to generate sufficient moment to keep the knees locked during standing after 2–4.5 years. The dorsiflexion moment produced by all four fibular Nerve Cuffs in the active participants exceeded the value required to prevent foot drop, but no tibial Nerve Cuffs were able to meet the plantarflexion moment that occurs during push-off at a normal walking speed. The selectivity of two multi-contact spiral Cuffs was examined and both were still highly selective for different motor unit populations for up to 6.3 years after implantation. The spiral Nerve Cuffs examined remain functional in motor and sensory neuroprostheses for 2–11 years after implantation. They exhibit stable charge thresholds, clinically relevant recruitment properties, and functional muscle selectivity. Non-penetrating spiral Nerve Cuff electrodes appear to be a suitable option for long-term clinical use on human peripheral Nerves in implanted neuroprostheses.
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Human distal sciatic Nerve fascicular anatomy: Implications for ankle control using Nerve-Cuff electrodes
Journal of rehabilitation research and development, 2012Co-Authors: Kenneth J Gustafson, Yanina Grinberg, Sheeba Joseph, Ronald J TrioloAbstract:INTRODUCTION Background Muscles innervated by the lower sciatic Nerve control plantar flexion and dorsiflexion as well as inversion and eversion of the talocrural (ankle) joint and are therefore critical for standing balance and walking functions. The sciatic Nerve originates in the lumbar and sacral spinal cord and supplies motor and sensory innervation to the lower limb. It has two major terminal branches, the tibial Nerve and common fibular Nerve. The common fibular (common peroneal) branches into the deep and superficial fibular (SF) Nerves and is commonly targeted in neural prostheses used to correct foot drop [1-5]. The deep fibular (DF) branch innervates the tibialis anterior muscle, which dorsiflexes and inverts the foot. The DF Nerve also innervates the extensor hallucis longus and extensor digitorum longus muscles, which primarily extend the toes and dorsiflex the foot, predominantly in non-weight-bearing positions. Muscles innervated by the SF Nerve (fibularis/peroneus longus and fibularis/peroneus brevis) evert and weakly plantarflex the foot and can counter the actions of tibialis anterior. The lateral sural cutaneous (LSC) and sural communicating branch Nerves also originate from the common fibular Nerve and have a sensory function that can elicit reflex activity. The tibial Nerve innervates the soleus and gastrocnemius muscles, which plantar flex the foot, generate propulsive power for walking, provide a mechanism for the rocker actions of the foot and ankle, and retard uncontrolled tibial advancement. The gastrocnemius muscles also cross the knee joint and help avoid load bearing in hyperextension. Tibial Nerve branches also innervate flexor digitorum longus and flexor hallucis longus, both of which flex the toes and plantar flex the foot, though mostly in a non-weight-bearing position. The medial sural cutaneous (MSC) Nerve, originating from the tibial Nerve, has sensory properties that can elicit reflex activity. Neural Prostheses for Ankle Control Implantable neural prostheses for foot drop generally use Nerve-Cuff electrodes to activate the motor Nerves and lift the foot, and some record sensory information to trigger stimulation [1-2,4,6-13]. However, most implantable neural prostheses provide only dorsiflexion to correct foot drop and do not provide active plantar flexion. Balanced dorsiflexion and active plantarflexion would improve the performance of neural prostheses for standing and walking after spinal cord injury and stroke. Detailed knowledge of the neuroanatomy and organization is required to design multicontact Cuff electrodes able to selectively activate the muscles needed to achieve all of these functions and improve the functionality and cosmesis of lower-limb neural prostheses. Furthermore, accurate knowledge of target Nerve morphology provides important design parameters for sizing and constructing Cuff electrodes to avoid mechanical trauma and maximize stimulation efficiency [14-16]. The fascicular anatomy of two human sciatic Nerves has been examined by McKinley [17] and Sunderland and Ray [18]. However, these studies do not provide adequate detail to allow Nerve-Cuff design. Techniques are available to selectively activate individual fascicles or groups within a Nerve and to mathematically represent the neural behavior in response to stimulation [19-21]. Selective stimulation allows control of multiple distal muscles at a single proximal location. Modeling and simulation studies based on the detailed femoral fascicular anatomy [22] have been successfully employed to design and optimize implantable femoral Nerve-Cuff electrodes [16]. This model-driven approach to designing selective electrodes for the femoral Nerve has been verified intra-operatively [23], and the resulting devices have been approved for human feasibility trials [24]. The first step in repeating this design and optimization procedure for the sciatic Nerve is the specification of the fascicular structure of the branches that innervate ankle musculature. …
Dominique M. Durand - One of the best experts on this subject based on the ideXlab platform.
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Motion control of the ankle joint with a multiple contact Nerve Cuff electrode: a simulation study
Biological Cybernetics, 2014Co-Authors: Hyun-joo Park, Dominique M. DurandAbstract:The flat interface Nerve electrode (FINE) has demonstrated significant capability for fascicular and subfascicular stimulation selectivity. However, due to the inherent complexity of the neuromuscular skeletal systems and Nerve–electrode interface, a trajectory tracking motion control algorithm of musculoskeletal systems for functional electrical stimulation using a multiple contact Nerve Cuff electrode such as FINE has not yet been developed. In our previous study, a control system was developed for multiple-input multiple-output (MIMO) musculoskeletal systems with little prior knowledge of the system. In this study, more realistic computational ankle/subtalar joint model including a finite element model of the sciatic Nerve was developed. The control system was tested to control the motion of ankle/subtalar joint angles by modulating the pulse amplitude of each contact of a FINE placed on the sciatic Nerve. The simulation results showed that the control strategy based on the separation of steady state and dynamic properties of the system resulted in small output tracking errors for different reference trajectories such as sinusoidal and filtered random signals. The proposed control method also demonstrated robustness against external disturbances and system parameter variations such as muscle fatigue. These simulation results under various circumstances indicate that it is possible to take advantage of multiple contact Nerve electrodes with spatial selectivity for the control of limb motion by peripheral Nerve stimulation even with limited individual muscle selectivity. This technology could be useful to restore neural function in patients with paralysis.
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Selectivity of multiple-contact Nerve Cuff electrodes: a simulation analysis
IEEE transactions on bio-medical engineering, 2001Co-Authors: A.q. Choi, J.k. Cavanaugh, Dominique M. DurandAbstract:Advances in functional neuromuscular stimulation (FNS) have increased the need for Nerve Cuff designs that can control multiple motor functions through selective stimulation of selected populations of axons. This selectivity has proved to be difficult to achieve. Recent experiments suggest that it is possible to slowly reshape peripheral Nerve without affecting its physiological function. Using computer simulations the authors have tested the hypothesis that changing the cross section of a Nerve from a round to a flat configuration can significantly improve the selectivity of a Nerve Cuff. The authors' introduce a new index to estimate selectivity to evaluate the various designs. This index is based on the ability of a Nerve electrode to stimulate a target axon without stimulating any other axons. The calculations involve a three-dimensional finite element model to represent the electrical properties of the Nerve and Cuff and the determination of the firing properties of individual axons. The selectivity rating was found to be significantly higher for the Flat Cuff than the Round Cuff. The result was valid with uniform or random distribution of axons and with a random distribution of fascicles diameters. Flattening of individual fascicles also improved the selectivity of the Flat Cuff but only when the number of contacts used was increased to maintain uniform contact density. Therefore, Cuff designs that can reshape the Nerve into flatter configurations should yield better Cuff performance than the cylindrical Cuffs but will require higher contact density.
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Measurement of external pressures generated by Nerve Cuff electrodes
IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society, 2000Co-Authors: F.a. Cuoco, Dominique M. DurandAbstract:When external pressures are applied to a peripheral Nerve, tissue damage can occur via compression and blood flow occlusion, resulting in degeneration and demyelination of axons. Although many types of Nerve electrodes have been designed to avoid or minimize this pressure during stimulation of the Nerve or recording of its activity, the measurement of the pressure exerted by these Cuffs has not been reported. Currently, only theoretical models are used to predict Nerve Cuff electrode pressures. The authors have developed a Nerve Cuff electrode pressure sensor to measure external pressures exerted by peripheral Nerve Cuff electrodes. The sensor has a high sensitivity, linear response with little hysteresis and reproducible output. Pressure measurements have been obtained for split-ring and spiral Cuff electrodes. The measurements obtained are in agreement with theoretical predictions. Moreover, they indicate that the pressures exerted by Cuffs currently used for stimulation generate only a small amount of pressure, which is below the pressure required to occlude blood flow in Nerves. The results also suggest that this new sensor can provide reliable measurement of external pressures exerted by Nerve electrodes and would be an important tool for comparing various Nerve Cuff electrode designs.
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Spiral Nerve Cuff electrode for recordings of respiratory output
Journal of applied physiology (Bethesda Md. : 1985), 1997Co-Authors: Mesut Sahin, Dominique M. Durand, Musa A. Haxhiu, Ismail A. DreshajAbstract:Sahin, Mesut, Musa A. Haxhiu, Dominique M. Durand, and Ismail A. Dreshaj. Spiral Nerve Cuff electrode for recordings of respiratory output. J. Appl. Physiol.83(1): 317–322, 1997.—The feasibility of...
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Whole Nerve recordings with the spiral Nerve Cuff electrode
Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1Co-Authors: Mesut Sahin, Dominique M. Durand, Musa A. HaxhiuAbstract:The feasibility of whole Nerve recordings from the hypoglossal (HG) Nerve is demonstrated in acute cats using the spiral Nerve Cuff electrode. A good contact between the Nerve and the electrodes, provided by the spiral Nerve Cuff due to its self-coiling property, should improve the signal-to-noise ratio. An instrumentation amplifier with very low input noise characteristics is also utilized. The performance of the spiral Cuff is studied in terms of signal-to-noise ratios and frequency characteristics. We conclude that the spiral Nerve Cuff electrode can reliably be used for acute recordings in a laboratory environment. >
Warren M. Grill - One of the best experts on this subject based on the ideXlab platform.
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Model-based analysis and design of Nerve Cuff electrodes for restoring bladder function by selective stimulation of the pudendal Nerve
Journal of neural engineering, 2013Co-Authors: Alexander R. Kent, Warren M. GrillAbstract:Objective. Electrical stimulation of the pudendal Nerve (PN) is being developed as a means to restore bladder function in persons with spinal cord injury. A single Nerve Cuff electrode placed on the proximal PN trunk may enable selective stimulation of distinct fascicles to maintain continence or evoke micturition. The objective of this study was to design a Nerve Cuff that enabled selective stimulation of the PN. Approach. We evaluated the performance of both flat interface Nerve electrode (FINE) Cuff and round Cuff designs, with a range of FINE Cuff heights and number of contacts, as well as multiple contact orientations. This analysis was performed using a computational model, in which the Nerve and fascicle cross-sectional positions from five human PN trunks were systematically reshaped within the Nerve Cuff. These cross-sections were used to create finite element models, with electric potentials calculated and applied to a cable model of a myelinated axon to evaluate stimulation selectivity for different PN targets. Subsequently, the model was coupled to a genetic algorithm (GA) to identify solutions that used multiple contact activation to maximize selectivity and minimize total stimulation voltage. Main results. Simulations did not identify any significant differences in selectivity between FINE and round Cuffs, although the latter required smaller stimulation voltages for target activation due to preserved localization of targeted fascicle groups. Further, it was found that a ten contact Nerve Cuff generated sufficient selectivity for all PN targets, with the degree of selectivity dependent on the relative position of the target within the Nerve. The GA identified solutions that increased fitness by 0.7–45.5% over single contact activation by decreasing stimulation of non-targeted fascicles. Significance. This study suggests that using an optimal Nerve Cuff design and multiple contact activation could enable selective stimulation of the human PN trunk for restoration of bladder function.
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neural and connective tissue response to long term implantation of multiple contact Nerve Cuff electrodes
Journal of Biomedical Materials Research, 2000Co-Authors: Warren M. Grill, Thomas J MortimerAbstract:The objective of this study was to characterize the tissue response to multiple contact spiral Nerve Cuff electrodes implanted on the sciatic Nerve of seven cats for 28-34 weeks. The Cuffs were surrounded by fibrous tissue encapsulation consisting of foreign body cells, collagen, and fibroblasts. Focal areas of abnormal neural morphology including perineurial thickening, endoneurial fibrosis, thinly myelinated axons, and focal reduction in the density of myelinated axons were noted in five of seven Nerves. In three implants, the percutaneous lead cable was destroyed by the animal pulling on the external leads. Morphological changes were observed in two of three Nerves from implants sustaining no known animal induced trauma (group A), and in three of four Nerves from implants damaged by the animal pulling at the leads (group B). All Nerves appeared normal 2 cm proximal to the Cuff. At the Cuff level, small regions of one fascicle in each of two Nerves (both group B) exhibited abnormalities, while the proximal and distal sections of both Nerves were normal. Distal to the Cuff, small regions of seven fascicles distributed among three Nerves (two group A, one group B) exhibited abnormalities. These Nerves were normal at the Cuff level but exhibited abnormalities in individual Nerve branches distal to the Cuff. The incidence and characteristics of the morphological abnormalities at the Cuff level are consistent with those observed in previous studies of Nerve Cuff electrodes, and support the hypothesis that spiral Cuff electrodes can be implanted with an internal diameter less than that of the Nerve and expand to accommodate the Nerve without compression The pattern of morphological abnormalities indicated that mechanical trauma had occurred at some time in the past, and the distribution suggested animal intervention and the lead cable as possible causes.
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Neural and connective tissue response to long‐term implantation of multiple contact Nerve Cuff electrodes
Journal of biomedical materials research, 2000Co-Authors: Warren M. Grill, J. Thomas MortimerAbstract:The objective of this study was to characterize the tissue response to multiple contact spiral Nerve Cuff electrodes implanted on the sciatic Nerve of seven cats for 28-34 weeks. The Cuffs were surrounded by fibrous tissue encapsulation consisting of foreign body cells, collagen, and fibroblasts. Focal areas of abnormal neural morphology including perineurial thickening, endoneurial fibrosis, thinly myelinated axons, and focal reduction in the density of myelinated axons were noted in five of seven Nerves. In three implants, the percutaneous lead cable was destroyed by the animal pulling on the external leads. Morphological changes were observed in two of three Nerves from implants sustaining no known animal induced trauma (group A), and in three of four Nerves from implants damaged by the animal pulling at the leads (group B). All Nerves appeared normal 2 cm proximal to the Cuff. At the Cuff level, small regions of one fascicle in each of two Nerves (both group B) exhibited abnormalities, while the proximal and distal sections of both Nerves were normal. Distal to the Cuff, small regions of seven fascicles distributed among three Nerves (two group A, one group B) exhibited abnormalities. These Nerves were normal at the Cuff level but exhibited abnormalities in individual Nerve branches distal to the Cuff. The incidence and characteristics of the morphological abnormalities at the Cuff level are consistent with those observed in previous studies of Nerve Cuff electrodes, and support the hypothesis that spiral Cuff electrodes can be implanted with an internal diameter less than that of the Nerve and expand to accommodate the Nerve without compression The pattern of morphological abnormalities indicated that mechanical trauma had occurred at some time in the past, and the distribution suggested animal intervention and the lead cable as possible causes.
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Stability of the input-output properties of chronically implanted multiple contact Nerve Cuff stimulating electrodes
IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society, 1998Co-Authors: Warren M. Grill, J.t. MortimerAbstract:The objective of this investigation was to measure the input-output (EO) properties of chronically implanted Nerve Cuff electrodes. Silicone rubber spiral Nerve Cuff electrodes, containing 12 individual platinum electrode contacts, were implanted on the sciatic Nerve of 7 adult cats for 28-34 weeks. Measurements of the torque generated at the ankle joint by electrical stimulation of the sciatic Nerve were made every 1-2 weeks for the first 6 weeks post-implant and every 3-5 weeks between 6 weeks and 32 weeks post-implant. In 3 implants the percutaneous lead cable was irreparably damaged by the animal within 4 weeks after implant and further testing was not possible. One additional lead cable was irreparably damaged by the animal at 17 weeks post-implant. The 3 remaining implants functioned for 28, 31, and 32 weeks. Input-output curves of ankle joint torque as a function of stimulus current amplitude were repeatable within an experimental session, but there were changes in EO curves between sessions. The degree of variability in I-O properties differed between implants and between different contacts within the same implant. After 8 weeks, the session to session changes in the stimulus amplitude required to generate 50% of the maximum torque (150) were smaller (15/spl plusmn/19%, mean /spl plusmn/s.d.) than the changes in 150 measured between 1 week and 8 weeks post-implant (34/spl plusmn/42%). Furthermore, the I-O properties were more stable across changes in limb position in the late post-implant period than in acutely implanted Cuff electrodes. These results suggest that tissue encapsulation acted to stabilize chronically implanted Cuff electrodes. Electrode movement relative to the Nerve, de- and regeneration of Nerve fibers, and the inability to precisely reproduce limb position in the measurement apparatus all may have contributed to the variability in I-O properties.
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Selective control of muscle activation with a multipolar Nerve Cuff electrode
IEEE transactions on bio-medical engineering, 1993Co-Authors: Claude Veraart, Warren M. Grill, J.t. MortimerAbstract:Acute experiments were performed on adult cats to study selective activation of medial gastrocnemius, soleus, tibialis anterior, and extensor digitorium longus with a Cuff electrode. A spiral Nerve Cuff containing twelve dot electrodes was implanted around the sciatic Nerve, and evoked muscle twitch forces were recorded in six experiments. Spatially isolated dot electrodes in four geometries (monopolar, longitudinal tripolar, tripolar with four common anodes, and two parallel tripoles) were combined with transverse field steering current(s) from an anode(s) located 180 degrees around from the cathode(s) to activate different regions of the Nerve trunk. A selectivity index was used to construct recruitment curves for a muscle with the optimal degree of selectivity. Physiological responses were correlated with the anatomical structure of the sciatic Nerve by identifying the Nerve fascicles innervating the four muscles, and by determining the relative positions of the electrodes and the Nerve fascicles. The results indicated that the use of transverse field steering current improved selectivity. The relative performance of the various electrode arrangements is discussed. >
Katharine H. Polasek - One of the best experts on this subject based on the ideXlab platform.
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Intraoperative evaluation of the spiral Nerve Cuff electrode on the femoral Nerve trunk
Journal of neural engineering, 2009Co-Authors: Katharine H. Polasek, Ronald J Triolo, Matthew A. Schiefer, Gilles C. Pinault, Dustin J. TylerAbstract:Evaluation of the Case Western Reserve University spiral Nerve Cuff electrode on the femoral Nerve trunk was performed intraoperatively in four subjects undergoing femoral-popliteal bypass surgery. The threshold, Nerve size and selective activation capabilities of the electrode were examined. The activation thresholds for the first muscle to be recruited were 6.3, 9, 10.6, and 37.4 nC with pulse amplitudes ranging from 0.3 to 1 mA. The femoral Nerve was found to have an elliptical cross-section with a major axis average length of 9 mm (8–12 mm) and a minor axis length of 1.5 mm. In all four subjects selective activation of the sartorius was obtained. In two subjects, the rectus femoris could also be selectively activated and in one subject the vastus medialis was selectively activated. Each electrode had four independent contacts that were evaluated separately. Small air bubbles were formed in the space over some contacts, preventing stimulation. This occurred in one contact in each electrode, leaving three effective stimulation channels. This issue has been corrected for future studies.
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Stimulation Stability and Selectivity of Chronically Implanted Multicontact Nerve Cuff Electrodes in the Human Upper Extremity
IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society, 2009Co-Authors: Katharine H. Polasek, Harry A. Hoyen, Robert F. Kirsch, Michael W. Keith, Dustin J. TylerAbstract:Nine spiral Nerve Cuff electrodes were implanted in two human subjects for up to three years with no adverse functional effects. The objective of this study was to look at the long term Nerve and muscle response to stimulation through Nerve Cuff electrodes. The Nerve conduction velocity remained within the clinically accepted range for the entire testing period. The stimulation thresholds stabilized after approximately 20 weeks. The variability in the activation over time was not different from muscle-based electrodes used in implanted functional electrical stimulation systems. Three electrodes had multiple, independent contacts to evaluate selective recruitment of muscles. A single muscle could be selectively activated from each electrode using single-contact stimulation and the selectivity was increased with the use of field steering techniques. The selectivity after three years was consistent with selectivity measured during the implant surgery. Nerve Cuff electrodes are effective for chronic muscle activation and multichannel functional electrical stimulation in humans.
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Nerve Cuff stimulation and the effect of fascicular organization for hand grasp in nonhuman primates
Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2009Co-Authors: Natalie Brill, Katharine H. Polasek, Emily R. Oby, Christian Ethier, Lee E. Miller, Dustin J. TylerAbstract:The overall goal of this work is to introduce Nerve Cuff electrodes into upper extremity hand grasp systems. The first challenge is to develop a Nerve Cuff electrode that can selectively activate multiple hand functions from common upper extremity peripheral Nerves. The Flat Interface Nerve Electrode (FINE) has shown selective stimulation capability in animal trials. The FINE wraps around the Nerve and gently reshapes the Nerve and aligns the fascicles within the Nerve. Our hypothesis is that the FINE can selectively stimulate multi-fascicular Nerves in the human upper extremity resulting in selective hand function. To assess the ability of the FINE to produce control of a hand with many degrees of freedom, we have tested the FINE in nonhuman primates. Fascicular organization and fascicle count are important factors to consider when determining electrode placement. The proximal Nerve is an attractive electrode location to access both extrinsic and intrinsic muscles in the upper extremity. A challenge with the nonhuman primate model is that the nonhuman primate median and ulnar Nerves both have uni-fascicular regions proximally. The human proximal median and ulnar Nerves have an encouraging anatomy of multi-fasciculated Nerves with redundant fascicles that may result in more selective hand function than is capable in the nonhuman primate.
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Intraoperative Evaluation of the Spiral Nerve Cuff Electrode for a Standing Neuroprosthesis
2007 3rd International IEEE EMBS Conference on Neural Engineering, 2007Co-Authors: Katharine H. Polasek, Ronald J Triolo, Matthew A. Schiefer, Gilles C. Pinault, Dustin J. TylerAbstract:Evaluation of the spiral Nerve Cuff electrode on the proximal femoral Nerve for a standing neuroprosthesis was performed intraoperatively in 4 subjects. The mean stimulation threshold was 17.7 plusmn 12 nC, similar to stimulation thresholds in upper extremity Nerves. The femoral Nerve was found to have an oblong cross section with an average width of 9 mm and height of 1-2 mm. In all 4 subjects where data was recorded, selective activation of at least one hip flexor (rectus femoris or sartorius) was possible. For a standing neuroprosthesis, knee extension without hip flexion is desired. A more selective electrode is needed for this application.
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Human Nerve Stimulation Thresholds and Selectivity Using a Multi-contact Nerve Cuff Electrode
IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society, 2007Co-Authors: Katharine H. Polasek, Harry A. Hoyen, Michael W. Keith, Dustin J. TylerAbstract:Testing of the recruitment properties and selective activation capabilities of a multi-contact spiral Nerve Cuff electrode was performed intraoperatively in 21 human subjects. The study was conducted in two phases. An exploratory phase with ten subjects gave a preliminary overview of the data and data collection process and a systematic phase with eleven subjects provided detailed recruitment properties. The mean stimulation threshold of 25 plusmn 17 nC was not significantly different than previous studies in animal models but much lower than muscle electrodes. The selectivity, defined as the percent of total activation of the first muscle recruited before another muscle reached threshold, ranged from 27% to 97% with a mean of 55%. In each case, the muscle that was selectively activated was the first muscle to branch distal to the Cuff location. This study serves as a preliminary evaluation of Nerve Cuff electrodes in humans prior to chronic implant in subjects with high tetraplegia
