On the design of a flexible stimulator for animal studies in auditory prostheses

Abstract

The present paper describes the design of two stimulators (bench-top and portable) which can be used for animal studies in cochlear implants. The bench-top stimulator is controlled by a highspeed digital output board manufactured by National Instruments and is electrically isolated. The portable stimulator is controlled by a personal digital assistant (PDA) and is based on a custom interface board that communicates with the signal processor in the PDA through the secure digital IO (SDIO) slot. Both stimulators can provide 8 charge-balanced, bipolar channels of pulsatile and analog-like electrical stimulation, delivered simultaneously, interleaved or using a combination of both modes. Flexibility is provided into the construction of arbitrary, but charge-balanced, pulse shapes, which can be either symmetric or asymmetric.

Design and Evaluation of a Personal Digital Assistant-based Research Platform for Cochlear Implants

“…The research platform as a whole comprises a portable processor in the form of a smart-phone or a PDA for implementing and evaluating novel speech processing algorithms [7];an interface board to connect the PDA with the Freedom [25] headpiece coil through the SDIO port of the PDA [26], [27];a bench-top and a portable stimulator (monopolar and bipolar) designed for electrical stimulation and neurophysiologic studies with animals [28]; anda recording unit for collecting evoked potentials from the human subjects [7]. …”

“…a bench-top and a portable stimulator (monopolar and bipolar) designed for electrical stimulation and neurophysiologic studies with animals [28]; and…”

“…At the core of the board is the 9-bit configurable current source chip, simply referred to as the BiSTM chip designed in our lab [28], [31]. The BiSTM chip is designed to provide programmable anodic and cathodic current pulses for stimulation.…”

“…The daughter board houses the BiSTM chip, analog output switches, a 5-V regulator, and voltage level shifters. The overall dimensions of the PDA with the portable stimulator unit are 15.2 cm × 7.6 cm × 1.6 cm with an overall weight of 300 g. For more details on the stimulator design, please refer to [28] and [31]. …”