System Design of a Low-power Wireless Link for Neural Recording in a Visual Prosthesis

Restoring visual function in blind people through technology can be challenging but very beneficial in improving the quality of life. For most cases of blindness, the only option is to stimulate the visual cortex directly. Such a system requires external cameras, image processing and implanted electrodes. Powering, stimulating the brain, and recording neural activity is preferably done wirelessly to avoid infections. The wireless link for sending the neural activity (uplink) out of the brain is vital as the neural recording is for calibration and monitoring. Uplink requirements on (low-power) consumption at the implanted transmitter and a high data rate lead us to compare two promising wireless link options. A system-level analysis is carried out on the feasibility of impulse radio ultrawideband (IR-UWB) by a worst-case link budget. A low power CMOS IR-UWB transmitter consisting of an on-off keying (OOK) modulator and an impulse generator is proposed closely, fulfiling low-power and high data rate requirements.