ECAP Spread of Excitation with Virtual Channels and Physical Electrodes.

ECAP Spread of Excitation with Virtual Channels and Physical Electrodes.
Hear Res. 2013 Oct 3;
Authors: Hughes ML, Stille LJ, Baudhuin JL, Goehring JL
Abstract
The primary goal of this study was to evaluate physiological spatial excitation patterns for stimulation of adjacent physical electrodes and intermediate virtual channels. Two experiments were conducted that utilized electrically evoked compound action potential (ECAP) spread-of-excitation (SOE) functions obtained with the traditional forward-masking subtraction method. These two experiments examined spatial excitation patterns for virtual-channel maskers and probes, respectively. In Experiment 1, ECAP SOE patterns were obtained for maskers applied to physical electrodes and virtual channels to determine whether virtual-channel maskers yield SOE patterns similar to those predicted from physical electrodes. In Experiment 2, spatial separation of SOE functions was compared for two adjacent physical probe electrodes and the intermediate virtual channel to determine the extent to which ECAP SOE patterns for virtual-channel probes are spatially separate from those obtained with physical electrodes. Data were obtained for three electrode regions (basal, middle, apical) for 35 ears implanted with Cochlear (N = 16) or Advanced Bionics (N = 19) devices. Results from Experiment 1 showed no significant difference between predicted and measured ECAP amplitudes for Advanced Bionics subjects. Measure...

Source: Hearing Research - October 3, 2013 Category: Audiology Authors: Hughes ML, Stille LJ, Baudhuin JL, Goehring JL Tags: Hear Res Source Type: research