Abstract
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.
Original language | English |
---|---|
Pages (from-to) | 973-982 |
Number of pages | 10 |
Journal | IEEE Transactions on Biomedical Engineering |
Volume | 54 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2007 |
Bibliographical note
Funding Information:This work was carried out based on academia-industry collaboration between the NBS-ERC of Seoul National University and the Nurobiosys Corporation. Electrode development was conducted in collaboration with the Epstein Laboratory at the University of California, San Francisco, with support from the National Institutes of Health (NIH) Contracts NO1-DC-2-1006 and Contract NO1-DC-3-1006. B. S. Wilson’s time was supported in part by the RTI Fellow Program and the remaining time was donated by him. A team of medical experts also helped. Thoughtful comments and suggestions from Dr. C. S. Kim, Dr. S. O. Chang from Seoul National University Hospital, Korea, and from Dr. K. S. Lee and S. H. Oh from Asan Medical Center, Seoul, Korea, and from Dr. J. T. McElveen, Jr., from the Carolina Ear and Hearing Clinic in Raleigh, NC, are all greatly appreciated. They would also like to thank W. H. Lim and Prof. N. S. Kim for their help with speech processor development. S. J. Kim would like to thank Dr. W. J. Heetderks of the United States National Institutes of Health for suggesting this project and for his encouragement throughout. Finally, the authors are grateful to the reviewers for their efforts to help us improve an initial version of this paper.
Funding Information:
Manuscript received August 9, 2006; revised January 19, 2007. This work was supported in part by the Korea Science and Engineering Foundation (KOSEF) through the Nano Bioelectronics and Systems Research Center (NBS-ERC) of Seoul National University under Grant R11-2000-075-01001-0 and in part by the Nurobiosys Corporation. Electrode development was conducted in collaboration with the Epstein Laboratory at the University of California, San Francisco with support from NIH contracts #NO1-DC-2-1006 and NO1-DC-3-1006. Asterisk indicates corresponding author.
Keywords
- Auditory prosthesis
- Cochlear implant system
- Continuous interleaved sampling
- Electrode array
- Hermetic package
- Neural prosthesis
- Neural stimulation