Different pulse shapes to obtain small fiber selective activation by anodal blocking - a simulation study

Vučković, A., Rijkhoff, N. J. M. and Struijk, J. J. (2004) Different pulse shapes to obtain small fiber selective activation by anodal blocking - a simulation study. IEEE Transactions on Biomedical Engineering, 51(5), pp. 698-706. (doi: 10.1109/TBME.2004.826663)

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Publisher's URL: http://dx.doi.org/10.1109/TBME.2004.826663

Abstract

The aim of this study was to investigate whether it is possible to reduce a charge per pulse, which is needed for selective nerve stimulation. Simulation is performed using a two-part simulation model: a volume conductor model to calculate the electrical potential distribution inside a tripolar cuff electrode and a human fiber model to simulate the fiber response to simulation. Selective stimulation is obtained by anodal block. To obtain anodal block of large fibers, long square pulses (>350 μs) with a relatively high currents (1-2.5 mA) are usually required. These pulses might not be safe for a long-term application because of a high charge per pulse. In this study, several pulse shapes are proposed that have less charge per pulse compared with the conventional square pulse and would therefore be safer in a chronic application. Compared with the conventional square pulse, it was possible to reduce the charge with all proposed pulse shapes, but the best results are obtained with a combination of a square depolarizing pulse and a blocking pulse. The charge per pulse was up to 32% less with that pulse shape than with a square pulse. Using a hyperpolarizing anodal prepulse preceding a square pulse, it was not possible to block nerve fibers in a whole nerve bundle and to obtain reduction of a charge per phase. Reduction of the charge could be achieved only with spatially selective blocking. The charge per phase was larger for the combination of a hyperpolarizing anodal prepulse and a two-step pulse than for the two-step pulse alone.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Vuckovic, Dr Aleksandra
Authors: Vučković, A., Rijkhoff, N. J. M., and Struijk, J. J.
College/School:College of Science and Engineering > School of Engineering > Biomedical Engineering
Journal Name:IEEE Transactions on Biomedical Engineering
Publisher:IEEE
ISSN:0018-9294
ISSN (Online):1558-2531

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