Two, dual-channel wireless neural recording and stimulation devices are presented. The basic version has a neural preamplifier in series with a second amplifier to provide a signal gain of 4000. A multiplexer selects the recording channel. An 8-bit ADC converts the analog neural data into a digital stream, which is Manchester-encoded and frequency-shift-key (FSK) modulated at 27.12 MHz, before being transmitted to the host transceiver. The device receives 125-kHz on-off-keyed (OOK) commands, allowing the user to change record channels, program stimulation parameters, and trigger stimulus.
The electrical performance of the basic version has been measured and compared to theoretical results. In vitro and in vivo animal experiments are reported. A comparison of wired and wireless data is in good agreement. Commands are properly received.
The advanced version has additional integration, circuit revisions, and provides support for on-board digital data processing. Basic functionality of the advanced prototype has been verified.