A Field-Programmable Analog Array Development Platform for Vestibular Prosthesis Signal Processing

We report on a vestibular prosthesis signal processor realized using an experimental field programmable analog array (FPAA). Completing signal processing functions in the analog domain, the processor is designed to help replace a malfunctioning inner ear sensory organ, a semicircular canal. Relying on angular head motion detected by an inertial sensor, the signal processor maps angular velocity into meaningful control signals to drive a current stimulator. To demonstrate biphasic pulse control a 1 k
$\Omega$
resistive load was placed across an H-bridge circuit. When connected to a 2.4 V supply, a biphasic current of 100
$\mu$
A was maintained at stimulation frequencies from 50–350 Hz, pulsewidths from 25–400
$\mu$
sec, and interphase gaps ranging from 25–250
$\mu$
sec.