WIRELESS MULTICHANNEL RECORDING/STIMULATION SYSTEM FOR NEURODYNAMIC STUDIES OF APLYSIA
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
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.
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