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 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.

Chronotropic, inotropic, and coronary artery blood flow responses to stimulation of specific canine sympathetic nerves and ganglia

1984 ◽  
Vol 62 (11) ◽  
pp. 1374-1381 ◽  
Author(s):  
R. D. Janes ◽  
D. E. Johnstone ◽  
J. A. Armour
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Coronary Blood Flow ◽  
Stellate Ganglion ◽  
Sympathetic Nerves ◽  
Neural Stimulation ◽  
Intramyocardial Pressure ◽  
Intact Heart ◽  
Cardiac Nerves ◽  
Stimulation Of

Electrical stimulation of the major sympathetic cardiac nerves and ganglia in chloralose-anesthetized, open-chest dogs elicited specific changes in heart rate, coronary blood flow, regional intramyocardial pressure, or intraventricular pressure. The effects produced by stimulation of a cardiac nerve were similar to, but never greater than those produced by stimulation of the ipsilateral stellate ganglion. Coronary blood flow was increased when neural stimulation increased intramyocardial pressure. In contrast, coronary blood flow was not altered significantly when neural stimulation induced tachycardia without increasing intramyocardial pressure. It is concluded that in the intact heart, electrical stimulation of the sympathetic cardiac nerves or ganglia increases coronary blood flow by augmenting intramyocardial pressure, not chronotropism.

Neural activity triggers Ca waves in hippocampal astrocyte networks

1991 ◽  
Vol 49 ◽  
pp. 148-149
Author(s):  
J.W. Dani ◽  
A. Chernjavsky ◽  
S.J. Smith
Keyword(s):  
Electrical Stimulation ◽  
Neural Activity ◽  
Normal Tissue ◽  
Neural Stimulation ◽  
Cultured Astrocytes ◽  
Neurotransmitter Glutamate ◽  
Hippocampal Astrocytes ◽  
Cultured Slices ◽  
The Brain ◽  
Stimulation Of

Recent findings that the neurotransmitter glutamate can trigger cytoplasmic Ca waves in networks of cultured astrocytes suggest a new range of possible mechanisms for neural-glial interaction and for signalling over distance within the brain. To explore some of these possibilities, we have used confocal microscopy and the Ca indicator fluo-3 to study organotypically cultured slices of rat hippocampus where astrocytes and neurons are intermingled in their normal tissue relationships. We observe that electrical stimulation of the dentate gyrus induces Ca signals in astrocytes of region CA3, acting via a TTX-sensitive neuronal fiber projection that releases glutamate as its major neurotransmitter. Astrocyte Ca transients can occur within two seconds of the onset of neural stimulation, and waves and oscillations result from sustained stimulation at frequencies as low as 2 Hz. Neurally-evoked astrocyte Ca waves propagate both within and between individual hippocampal astrocytes at velocities of 10 - 20 um/sec, while the oscillations have periods of approximately 20 sec (at 21 °C).

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