A Fully Implantable Opto-Electro Closed-Loop Neural Interface for Motor Neuron Disease Studies

• Published in: IEEE transactions on biomedical circuits and systems 2022-10, Vol.16 (5), p.752-765
• Main Authors: Liu, Fangqi, Wu, Yu, Almarri, Noora, Habibollahi, Maryam, Lancashire, Henry Thomas, Bryson, Barney, Greensmith, Linda, Jiang, Dai, Demosthenous, Andreas
• Format: Article
• Language: English
• Subjects: Biomedical optical imaging; Bluetooth; Computer applications; Electrical stimuli; Electronic packaging; Equipment Design; Humans; Implantable devices; Implants; Integrated circuits; Motor Neuron Disease; Motor neuron diseases; Motor neurone disease; neural recording; Neurons; opto-electro stimulation; Optogenetics; Packaging; Prostheses and Implants; Rechargeable batteries; Recording; Rodents; Stimulated emission; Stimulation; Stimulators; Telemetry; Waveforms; Wireless Technology
• ISSN: 1932-4545; 1940-9990
• DOI: 10.1109/TBCAS.2022.3202026

This paper presents a fully implantable closed-loop device for use in freely moving rodents to investigate new treatments for motor neuron disease. The 0.18 μm CMOS integrated circuit comprises 4 stimulators, each featuring 16 channels for optical and electrical stimulation using arbitrary current waveforms at frequencies from 1.5 Hz to 50 kHz, and a bandwidth programmable front-end for neural recording. The implant uses a Qi wireless inductive link which can deliver >100 mW power at a maximum distance of 2 cm for a freely moving rodent. A backup rechargeable battery can support 10 mA continuous stimulation currents for 2.5 hours in the absence of an inductive power link. The implant is controlled by a graphic user interface with broad programmable parameters via a Bluetooth low energy bidirectional data telemetry link. The encapsulated implant is 40 mm × 20 mm × 10 mm. Measured results are presented showing the electrical performance of the electronics and the packaging method.