Laboratory prototype of cochlear implant: Design and techniques

This paper presents design overview of a low cost prototype of Cochlear Implant developed from commercial off-the-shelf components. Design scope includes speech processing module implemented on a commercial digital signal processor, transcutaneous data and power transceiver developed from a single pair of inductive coils and finally a stimulator circuitry for cochlear stimulation. Different speech processing strategies such as CIS, SMSP and F0/F1 have been implemented and tested using a novel, indigenously developed speech processing research module which evaluates the performance of speech processing strategies in software, hardware and practical scenarios. Design overview, simulations and practical results of an optimized inductive link using Class E Power Amplifier are presented. Link was designed at a carrier frequency of 2.5 MHz for 100 mW output power. Receiver logic design and stimulator circuitry was implemented using a PIC microcontroller and off-the-shelf electronic components. Results indicate 40% link efficiency with 128 kbps data transfer rate. This low cost prototype can be used for undertaking cochlear implant research in laboratories.