Development of a Wireless Neural Record System

Abstract

Purpose: : This work is related to the efforts of the Boston Retinal Implant Project to develop a sub-retinal prosthesis to restore vision to the blind. The specific purpose of this project was to develop a wireless recording system in order to gain greater insights about neurological response patterns. This system in capable of recording microvolt signals from the test subject and transmitting the signals over a wireless local area network to a nearby computer. The test subject is allowed free movements because of the small size and portability of the recording system.

Methods: : The system on the test subject is microcontroller based. The microcontroller interfaces with three peripheral devices: multiplexer for switching between neural record sites, an amplifier and a RF transmitter. The system on the test subject is battery powered. In order to conserve power, the microcontroller operates in a low power shutdown mode the majority of the time. It is capable of powering up in a periodic manner to perform recording and transmission. The carrier frequency for RF transmission is 2.4GHz.

Results: : As the system evolved it has been in fairly constant experimental use. The recordings have been shown to cover a wide range of possible stimulation patterns. The recording system has been shown to obtain reproducible response patterns.

Conclusions: : The system has worked effectively in recording biological signals but the experimental program needs to be continually expanded to include more complex stimulation and recording patterns.

Keywords: neuro-ophthalmology: diagnosis • electrophysiology: non-clinical