A power and data link for a wireless-implanted neural recording system.

A wireless cortical neural recording system with a miniature-implanted package is needed in a variety of neuroscience and biomedical applications. Toward that end, we have developed a transcutaneous two-way communication and power system for wireless neural recording. Wireless powering and forward data transmission (into the body) at 1.25 Mbps is achieved using a frequency-shift keying modulated class E converter. The reverse telemetry (out of the body) carrier frequency is generated using an integer-N phase-locked loop, providing the necessary wideband data link to support simultaneous reverse telemetry from multiple implanted devices on separate channels. Each channel is designed to support reverse telemetry with a data rate in excess of 3 Mbps, which is sufficient for our goal of streaming 16 channels of raw neural data. We plan to incorporate this implantable power and telemetry system in a 1-cm diameter single-site cortical neural recording implant.

Inductive link design for miniature implants.

Advances in microfabrication have allowed the integration of large numbers of electrodes onto one platform. The small size and high channel density of these microelectrode arrays which promise improved performance of a neural prosthesis also complicate the design of an inductive link to achieve efficient powering and communication with the implant. Stimulating or recording with many channels requires high data rate transmission. At the same time, power must be transmitted to the implanted device without exceeding power dissipation limits within the body. Using conventional design techniques, achieving all of these competing requirements simultaneously can require many time consuming iterations. It is proposed that a transcutaneous power and data link can be optimized to meet system level design parameters (power dissipation, data rate, secondary voltage, etc.) by having an analytic understanding of the interacting link level design parameters (receiver radius, carrier frequency, number of turns, implant location, etc.). We demonstrated this technique with the design of a transcutaneous power and data link for an intracortical visual prosthesis.