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 Ω resistive load was placed across an H-bridge circuit. When connected to a 2.4 V supply, a biphasic current of 100 μA was maintained at stimulation frequencies from 50-350 Hz, pulsewidths from 25-400 μ sec, and interphase gaps ranging from 25-250 μsec.