A low-noise receiver for multichannel wireless neural recording.
We present a high performance wideband receiver for multichannel wireless implantable neural recording systems (WINeR) utilizing pulse width modulation of time division multiplexed (PWM-TDM) samples. The receiver consists of a 50 MHz approximately 1 GHz tunable down-converter with 75 MHz bandwidth, frequency shift keying and PWM demodulators, and a high throughput USB interface. Several IF gain stages, passive LC filters, and an FPGA-based time-to-digital converter (TDC) with time interval resolution of 428 ps have significantly enhanced the receiver performance and extended its receiving range. A 2 MB SDRAM is used as a buffer between the TDC and USB to ensure continuous throughput for the digitized raw data at data rates up to 10 Mb/s. The receiver performance is evaluated with a 6-channel WINeR transmitter, showing that the entire system input referred noise with this receiver is 9.8 and 12.7 microV(rms) at 0.5 and 3.5 m distances, respectively, which are equivalent to 8.2 and 7.9 bits of resolution at 640 ksample/s.
Yin
Ming
M
Department of Electrical and Computer Engineering, NCSU, Raleigh, NC, USA.
Ghovanloo
M
M
D000200:Action Potentials / Q000502:physiology; D000669:Amplifiers, Electronic; D004567:Electrodes, Implanted; D004867:Equipment Design; D009474:Neurons / Q000502:physiology; D009482:Neurophysiology / Q000295:instrumentation*; D019736:Prostheses and Implants; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013686:Telemetry / Q000295:instrumentation*