Sensory particles with optical telemetry

Publication Date


Document Type

Conference Proceeding

Publication Title

2020 IEEE International Symposium on Circuits and Systems (ISCAS)




Current retinal prostheses provide electrical stimulation without feedback from the stimulated neurons. Incorporation of multichannel recording electronics would typically require trans-scleral cables for power supply and data transmission. In this work, we explore a wireless, optoelectronic, miniature, modular, and distributed electro-neural interface for recording, which we call Sensory Particles with Optical Telemetry (SPOT). It can be used in an advanced, bi-directional retinal prosthesis and other sensory applications. Emphasis is placed on the novel telemetry stage. SPOTs are powered by near-infrared light and transmit information by light. As a proof of concept, we designed and built a low-power, small-footprint linear transconductance circuit utilizing chopper stabilization in 130nm CMOS. Our design achieved 57 mS transconductance within 3.5 kHz bandwidth, and a near-infrared (NIR) power density of 0.5 mW/mm2, well within the ocular and thermal safety limits. The telemetry circuit consumes 0.015 mm2 area, and each SPOT can be powered by a single photovoltaic (PV) supply of area 0.0056 mm2. Electrical spikes transmitted by an 850nm LED were detected with 15 dB SNR, at the output of the optical link.

Funding Number


Funding Sponsor

Stanford University


Biomedical electronics, Biomedical telemetry, Near-Infrared light, Neural recording, Optical telemetry


Electrical Engineering