ON DEVELOPMENT OF TOTALLY IMPLANTABLE VESTIBULAR PROSTHESIS

This paper presents a functional architecture, system level design, and preliminary experimental evaluation of a unilateral vestibular prosthesis. The sensing element of the prosthesis is a custom designed one-axis MEMS gyroscope. Similarly to the natural semicircular canal, the microscopic gyroscope senses angular motion of the head and generates voltages proportional to the corresponding angular accelerations. Then, voltages are sent to the pulse generating unit where angular motion is translated into voltage pulses. The voltage pulses are converted into current pulses and are delivered through specially designed electrodes, conditioned to stimulate the corresponding vestibular nerve branch. Our preliminary experimental evaluations of the prosthesis on a rate table indicate that the device's output matches the average firing rate of vestibular neurons to those in animal models reported in the literature. The proposed design is scalable; the sensing unit, pulse generator, and the current source can be potentially implemented on a single chip using integrated MEMS technology.