by Samsukha, Paras

Abstract (Summary)
In this research, a bi-directional wireless implantable unit and an external transceiver which can be used for recording and stimulating neural activity of marine mollusk Aplysia Californica, has been developed. The system supports bidirectional wireless telemetry in a saltwater environment, using frequency shift keying (FSK) at 27.1 MHz to transmit data at 62.5 kbps data rate, and using on-off Keying (OOK) at 125 kHz to receive commands. The implanted device is powered using a 3-V, 160-mAh lithiumion battery, consumes 21 mW of power, weighs 21.9 gm including the battery, is 4.5 cm by 1.8 cm in size and can operate for 23 hr continuously before the battery dies. Measurement of acute neural activity from a live animal has been demonstrated using this device. A fully monolithic bandpass amplifier for neural signal recording in large arrays has been designed and tested. The measured passband gain is 37.9 dB from 25 Hz to 15 kHz and input-referred noise is 1.04 ?V rms, with a power consumption of 162 ?W and a die area of 0.13 mm2 in a standard 0.5-?m CMOS process. The technology is also demonstrated via a 2x2-mm, fully integrated 4-channel application specific integrated circuit (ASIC) in 0.5-?m technology. The ASIC features a three-stage frontend amplifier which provides a maximum gain of 80 dB. The power consumption has been optimized considering the noise (1-?V r.m.s), bandwidth (2 kHz) and resolution (8-bits) requirements. The calculated power consumption per channel of the front end amplifier is 22 ?Watt. The architecture and the performance of the ASIC are scalable to multiple channels. As such, the device could serve as the basis for a closed-loop controller for prosthetic devices or deep brain stimulation.
Bibliographical Information:


School:Case Western Reserve University

School Location:USA - Ohio

Source Type:Master's Thesis

Keywords:neural recording implantable wireless low power multichannel


Date of Publication:01/01/2009

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