THE ADVANCED COMBI 40+ COCHLEAR IMPLANT

A 12-channel cochlear implant (CI) for high-rate pulsatile stimulation strategies is presented. Symmetric biphasic current pulses can be gen erated up to a maximum pulse repetition rate of 18.18 kpulses/second. The stimulation pulse amplitude can be selected within 1.5 mu A-1.5 mA . Data and power are transcutaneously transferred using a single radio frequency (RF) channel. A fully digital data transfer format is employ ed al an overall data rate of 600 kBit/second. The implant contains a single mixed analog/digital CMOS-ASIC (Application Specific Integrated Description) for data synchronization and stimulus generation. Stimul ation signals are applied via a monopolar intracochlear multichannel e lectrode. Output capacitors for each channel are employed for safety r easons. A self-calibrating back telemetry system is included for estim ating the channel impedances and field distribution along the electrod e array. Dimensions of the ceramic package of the implant are only 33. 50 x 23.40 x 3.95 mm(3).