Design for a simplified cochlear implant system.
A simplified cochlear implant (CI) system would be appropriate for widespread use in developing countries. Here, we describe a CI that we have designed to realize such a concept. The system implements 8 channels of processing and stimulation using the continuous interleaved sampling (CIS) strategy. A generic digital signal processing (DSP) chip is used for the processing, and the filtering functions are performed with a fast Fourier transform (FFT) of a microphone or other input. Data derived from the processing are transmitted through an inductive link using pulse width modulation (PWM) encoding and amplitude shift keying (ASK) modulation. The same link is used in the reverse direction for backward telemetry of electrode and system information. A custom receiver-stimulator chip has been developed that demodulates incoming data using pulse counting and produces charge balanced biphasic pulses at 1000 pulses/s/electrode. This chip is encased in a titanium package that is hermetically sealed using a simple but effective method. A low cost metal-silicon hybrid mold has been developed for fabricating an intracochlear electrode array with 16 ball-shaped stimulating contacts.
An
Soon Kwan
SK
School of Electrical Engineering and Computer Science, Seoul National University, Seoul 151-744, Korea. soonkwan@helios.snu.ac.kr
Park
Se-Ik
SI
Jun
Sang Beom
SB
Lee
Choong Jae
CJ
Byun
Kyung Min
KM
Sung
Jung Hyun
JH
Wilson
Blake S
BS
Rebscher
Stephen J
SJ
Oh
Seung Ha
SH
Kim
Sung June
SJ
D003054:Cochlear Implants; D004599:Electric Stimulation Therapy / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008904:Miniaturization; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D049250:Speech Recognition Software; D013813:Therapy, Computer-Assisted / Q000295:instrumentation* / Q000379:methods