Signal Processing Design for Cochlear Implant System Using Piezoelectric Sensor

Abstract

Today, the cochlear implant system is the most successful auditory prosthesis for the patients suffering hair cell loss or damage. The current cochlear implant system consists of an implantable electrode array for the stimulation and an external signal processor includ-ing a microphone and a battery. However, the conventional cochlear implant system is composed of a heavy signal processor. Furthermore, the exposure of an external signal processor causes a cosmetic problem to the patients. Therefore, the cochlear implant sys-tem is required to reduce size and power consumption. In the thesis, to realize the implementation of an entirely implantable cochlear sys-tem, the signal processing system is studied when a piezoelectric sensor is employed. When a mechanical stress is applied, the piezoelectric sensor produces an electrical charge. The acoustic sounds picked up by the piezoelectric sensor are amplified and transmitted to the microprocessor. The microprocessor used the CC430F6137. This system is a multi-channel system and applied the continuous interleaved sampling (CIS) algorithm to make a charge-balanced biphasic pulse. Also, this system is referred to as miniaturized system comprised of sensing, processing, and actuating functions which are combined on-to a single board. Building a complete printed circuit board (PCB) involves hardware (H/W) and software (S/W) design. The proposed signal processing system embedded with PCB has been tested and verified for future animal experiment. ⓒ 2014 DGIST