Distribution of Electrical Stimulation Current in a Planar Multilayer Anisotropic Tissue

2008 ◽  
Vol 55 (2) ◽  
pp. 660-670 ◽  
Author(s):  
Luca Mesin ◽  
Roberto Merletti
Keyword(s):  
Electrical Stimulation ◽  
Stimulation Current

scholarly journals Vestibular implantation and longitudinal electrical stimulation of the semicircular canal afferents in human subjects

2015 ◽  
Vol 113 (10) ◽  
pp. 3866-3892 ◽  
Author(s):  
James O. Phillips ◽  
Leo Ling ◽  
Kaibao Nie ◽  
Elyse Jameyson ◽  
Christopher M. Phillips ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Human Subjects ◽  
Vestibular Function ◽  
Slow Phase ◽  
Vestibular Loss ◽  
Stimulation Current ◽  
Eye Velocity ◽  
Over Time ◽  
Stimulation Of

Animal experiments and limited data in humans suggest that electrical stimulation of the vestibular end organs could be used to treat loss of vestibular function. In this paper we demonstrate that canal-specific two-dimensionally (2D) measured eye velocities are elicited from intermittent brief 2 s biphasic pulse electrical stimulation in four human subjects implanted with a vestibular prosthesis. The 2D measured direction of the slow phase eye movements changed with the canal stimulated. Increasing pulse current over a 0–400 μA range typically produced a monotonic increase in slow phase eye velocity. The responses decremented or in some cases fluctuated over time in most implanted canals but could be partially restored by changing the return path of the stimulation current. Implantation of the device in Meniere's patients produced hearing and vestibular loss in the implanted ear. Electrical stimulation was well tolerated, producing no sensation of pain, nausea, or auditory percept with stimulation that elicited robust eye movements. There were changes in slow phase eye velocity with current and over time, and changes in electrically evoked compound action potentials produced by stimulation and recorded with the implanted device. Perceived rotation in subjects was consistent with the slow phase eye movements in direction and scaled with stimulation current in magnitude. These results suggest that electrical stimulation of the vestibular end organ in human subjects provided controlled vestibular inputs over time, but in Meniere's patients this apparently came at the cost of hearing and vestibular function in the implanted ear.

Intraoperative multi-pulse transcranial electric stimulation: the effect of general anesthetics impact on the excitability of the pyramidal tract

2020 ◽  
Vol 22 (4) ◽  
pp. 47-52
Author(s):  
O. A. Toporkova ◽  
M. V. Aleksandrov ◽  
R. V. Nazarov ◽  
V. S. Chernyj
Keyword(s):  
Electrical Stimulation ◽  
Motor Neuron ◽  
General Anesthesia ◽  
Neurophysiological Monitoring ◽  
Transcranial Electrical Stimulation ◽  
General Anesthetics ◽  
General Anesthetic ◽  
Periodic Patterns ◽  
Stimulation Current ◽  
Alpha Motor Neuron

The results of intraoperative neurophysiological monitoring during neurosurgical treatment of pathological processes in the central nervous system are analyzed. The mechanisms of action of general anesthetics on the excitability of the pyramidal system during anesthesia with propofol and sevoflurane have been clarified. It has been established that anesthetics with different mechanisms differ in their effect on excitability and conductivity in the system motor neuron of the cortex pathways alpha-motor neuron. Inhalation anesthetic sevoflurane causes a slowdown in the conduction of a nerve impulse and a violation of the mechanisms of convergence of excitation on the alpha-motor neuron of the spinal cord. In this regard, during general anesthesia with sevoflurane, in order to achieve the effectiveness of transcranial electrical stimulation, the number of stimuli in the package should be increased first with a relatively high stimulation current. Under general anesthesia with propofol, the processes of convergence of excitation are not inhibited, therefore, effective electrical stimulation is achieved by increasing the stimulation current with a stable number of stimuli. With an increase in doses of general anesthetic to a level at which periodic patterns are recorded on the electroencephalogram, a deep inhibition of the excitability and conductivity of the pyramidal system occurs. Under these conditions, effective performance of transcranial electrical stimulation is achieved with submaximal values of the current strength and the number of stimuli.

scholarly journals Fast simulation and optimization tool to explore selective neural stimulation

2016 ◽  
Vol 26 (3) ◽  
Author(s):  
Mélissa Dali ◽  
Olivier Rossel ◽  
David Guiraud
Keyword(s):  
Electrical Stimulation ◽  
Neural Stimulation ◽  
Fast Simulation ◽  
Tool Chain ◽  
Spatial Selectivity ◽  
Simulation And Optimization ◽  
Cuff Electrodes ◽  
Muscular Function ◽  
Stimulation Current ◽  
Stimulation Of

In functional electrical stimulation, selective stimulation of axons is desirable to activate a specific target, in particular muscular function. This implies to simulate a fascicule without activating neighboring ones i.e. to be spatially selective. Spatial selectivity is achieved by the use of multicontact cuff electrodes over which the stimulation current is distributed. Because of the large number of parameters involved, numerical simulations provide a way to find and optimize electrode configuration. The present work offers a computation effective scheme and associated tool chain capable of simulating electrode-nerve interface and find the best spread of current to achieve spatial selectivity.

scholarly journals Garments for functional electrical stimulation: Design and proofs of concept

2019 ◽  
Vol 6 ◽  
pp. 205566831985434
Author(s):  
Bastien Moineau ◽  
Cesar Marquez-Chin ◽  
Milad Alizadeh-Meghrazi ◽  
Milos R Popovic
Keyword(s):  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Full Range ◽  
Sensory Threshold ◽  
Stimulation Threshold ◽  
Promising Alternative ◽  
Maximal Stimulation ◽  
Electrode Lead ◽  
Repeated Use ◽  
Stimulation Current

Introduction Repeated use of functional electrical stimulation can promote functional recovery in individuals with neurological paralysis. We designed garments able to deliver functional electrical stimulation. Methods Shirts and pants containing electrodes knitted with a conductive yarn were produced. Electrodes were moistened with water before use. Stimulation intensity at four thresholds levels (sensory, movement, full range of motion, and maximal), stimulation comfort, and electrical properties of the interface were tested in one able-bodied subject with garment electrodes and size-matched conventional gel electrodes. The pants and shirt were then used to explore usability and design limitations. Results Compared to gel electrodes, fabric electrodes had a lower sensory threshold (on forearm muscles) but they had a higher maximal stimulation threshold (for all tested muscles). The stimulation delivery was comfortable when the garment electrodes were recently moistened; however, as the electrodes dried (within 9 to 18 min) stimulation became unpleasant. Inconsistent water content in the fabric electrodes caused inconsistent intensity thresholds and inconsistent voltage necessary to apply a desired stimulation current. Garments’ tightness and impracticality of electrode lead necessitate further design improvement. Conclusions Fabric electrodes offer a promising alternative to gel electrodes. Further work involving people with paralysis is required to overcome the identified challenges.

scholarly journals FUNCTIONAL ELECTRICAL STIMULATION FOR NEURO REHABILITATION. A NEW DESIGN PARADIGM

2012 ◽  
Vol 02 (03) ◽  
pp. 14-15
Author(s):  
Subramanya K. ◽  
Ajithanjaya Kumar Mijar Kanakabettu
Keyword(s):  
Electrical Stimulation ◽  
Electrical Activity ◽  
Functional Electrical Stimulation ◽  
Neurological Disorders ◽  
Closed Loop ◽  
Design Principles ◽  
Ideal Candidate ◽  
Design Paradigm ◽  
Stimulation Current ◽  
Novel Design

AbstractOne of the most exciting recent advances in the neuroprosthetics field has been the application of biosignals in the design of functional electrical stimulation (FES) devices. An Electromyogram (EMG) measures the electrical activity in muscles and is often considered as ideal candidate biosignal for designing closed-loop controlled FES system. In this brief communication, we propose a novel design paradigm of a synergistic benefit of incorporating two different design principles in development of an EMG controlled FES system that hold promise for the future of rehabilitation of stroke and other neurological disorders. The proposed system will detect the residual EMG signals from the muscle and suitably adjust the stimulation current amplitude and stimulate the paralyzed muscles with a 'natural' EMG pattern envelope. We offer this design as a fruitful area for fuing recent advances in the neuroprosthetics field has been the application of biosignals in the design of functional electrical stimulation (FES) devices. An Electromyogram (EMG) measures the electrical activity in muscles and is often considered as ideal candidate biosignal for designing closed-loop controlled FES system. In this brief communication, we propose a novel design paradigm of a synergistic benefit of incorporating two different design principles in development of an EMG controlled FES system that hold promise for the future of rehabilitation of stroke and other neurological disorders. The proposed system will detect the residual EMG signals from the muscle and suitably adjust the stimulation current amplitude and stimulate the paralyzed muscles with a 'natural' EMG pattern envelope. We offer this design as a fruitful area for future research and clinical application.

Comparison between the effects of 4 different electrical stimulation current waveforms on isometric knee extension torque and perceived discomfort in healthy women

2014 ◽  
Vol 51 (1) ◽  
pp. 76-82 ◽  
Author(s):  
Lucas Ogura Dantas ◽  
Amilton Vieira ◽  
Aristides Leite Siqueira ◽  
Tania Fatima Salvini ◽  
João Luiz Quagliotti Durigan
Keyword(s):  
Electrical Stimulation ◽  
Knee Extension ◽  
Healthy Women ◽  
Isometric Knee Extension ◽  
Stimulation Current

scholarly journals Activation of ganglion cells and axon bundles using epiretinal electrical stimulation

2017 ◽  
Vol 118 (3) ◽  
pp. 1457-1471 ◽  
Author(s):  
Lauren E. Grosberg ◽  
Karthik Ganesan ◽  
Georges A. Goetz ◽  
Sasidhar S. Madugula ◽  
Nandita Bhaskhar ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Retinal Ganglion Cells ◽  
Large Scale ◽  
Ganglion Cells ◽  
Propagation Speed ◽  
Peripheral Retina ◽  
Retinal Ganglion ◽  
Central Retina ◽  
Axon Bundle ◽  
Stimulation Current

Epiretinal prostheses for treating blindness activate axon bundles, causing large, arc-shaped visual percepts that limit the quality of artificial vision. Improving the function of epiretinal prostheses therefore requires understanding and avoiding axon bundle activation. This study introduces a method to detect axon bundle activation on the basis of its electrical signature and uses the method to test whether epiretinal stimulation can directly elicit spikes in individual retinal ganglion cells without activating nearby axon bundles. Combined electrical stimulation and recording from isolated primate retina were performed using a custom multielectrode system (512 electrodes, 10-μm diameter, 60-μm pitch). Axon bundle signals were identified by their bidirectional propagation, speed, and increasing amplitude as a function of stimulation current. The threshold for bundle activation varied across electrodes and retinas, and was in the same range as the threshold for activating retinal ganglion cells near their somas. In the peripheral retina, 45% of electrodes that activated individual ganglion cells (17% of all electrodes) did so without activating bundles. This permitted selective activation of 21% of recorded ganglion cells (7% of expected ganglion cells) over the array. In one recording in the central retina, 75% of electrodes that activated individual ganglion cells (16% of all electrodes) did so without activating bundles. The ability to selectively activate a subset of retinal ganglion cells without axon bundles suggests a possible novel architecture for future epiretinal prostheses. NEW & NOTEWORTHY Large-scale multielectrode recording and stimulation were used to test how selectively retinal ganglion cells can be electrically activated without activating axon bundles. A novel method was developed to identify axon activation on the basis of its unique electrical signature and was used to find that a subset of ganglion cells can be activated at single-cell, single-spike resolution without producing bundle activity in peripheral and central retina. These findings have implications for the development of advanced retinal prostheses.

scholarly journals Characteristics of Tetanic Force Produced by the Sternomastoid Muscle of the Rat

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Stanislaw Sobotka ◽  
Liancai Mu
Keyword(s):  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Muscle Force ◽  
Muscle Length ◽  
Threshold Current ◽  
Contractile Properties ◽  
Normative Values ◽  
Muscle Reinnervation ◽  
Stimulation Current

The sternomastoid (SM) muscle plays an important role in supporting breathing. It also has unique anatomical advantages that allow its wide use in head and neck tissue reconstruction and muscle reinnervation. However, little is known about its contractile properties. The experiments were run on rats and designed to determine in vivo the relationship between muscle force (active muscle contraction to electrical stimulation) with passive tension (passive force changing muscle length) and two parameters (intensity and frequency) of electrical stimulation. The threshold current for initiating noticeable muscle contraction was 0.03 mA. Maximal muscle force (0.94 N) was produced by using moderate muscle length/tension (28 mm/0.08 N), 0.2 mA stimulation current, and 150 Hz stimulation frequency. These data are important not only to better understand the contractile properties of the rat SM muscle, but also to provide normative values which are critical to reliably assess the extent of functional recovery following muscle reinnervation.

M-wave properties during progressive motor unit activation by transcutaneous stimulation

2004 ◽  
Vol 97 (2) ◽  
pp. 545-555 ◽  
Author(s):  
Dario Farina ◽  
Andrea Blanchietti ◽  
Marco Pozzo ◽  
Roberto Merletti
Keyword(s):  
Electrical Stimulation ◽  
Motor Unit ◽  
Biceps Brachii ◽  
Constant Current ◽  
Transcutaneous Electrical Stimulation ◽  
Biceps Brachii Muscle ◽  
Surface Electromyogram ◽  
M Wave ◽  
Transcutaneous Stimulation ◽  
Stimulation Current

The aim of this study was to interpret changes in experimentally recorded M waves with progressive motor unit (MU) activation based on simulation of the surface electromyogram. Activation order during transcutaneous electrical stimulation was analyzed by investigating M-wave average rectified value, spectral properties, and conduction velocity (CV) during electrically elicited contractions. M-waves were detected from the biceps brachii muscle of 10 healthy male subjects by a linear adhesive array of eight electrodes. Electrical stimulation was delivered to the motor point at either constant current intensity (40, 60, 80, and 100% of the supramaximal stimulation current) or with linearly increasing current. A model of surface electromyogram generation that varied activation order based on MU size and location was used to interpret the experimental results. From the experimental and model analysis, it was found that 1) MUs tended to be activated from low to high CV and from the superficial to the deep muscle layers with increasing transcutaneous electrical stimulation of the biceps brachii muscle, and 2) characteristic spectral frequencies of the M-wave were affected by many factors other than average CV (such as the activation order by MU location or the spread of the MU innervation zones and CVs), thus decreasing with a concomitant increase in CV during progressive MU activation.

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