A 4.49nW/Pixel Light-to-Stimulus Duration Converter-Based Retinal Prosthesis Chip
- Resource Type
- Periodical
- Authors
- Choi, D.; Roh, H.; Im, M.; Jee, D.
- Source
- IEEE Transactions on Biomedical Circuits and Systems IEEE Trans. Biomed. Circuits Syst. Biomedical Circuits and Systems, IEEE Transactions on. 15(6):1140-1148 Dec, 2021
- Subject
- Bioengineering
Components, Circuits, Devices and Systems
Retina
Photodiodes
Low-power electronics
Brightness
Implants
CMOS process
Prosthetics
CMOS sensor
implantable chip
local return
light-to-stimulus duration converter
low power
retinal prostheses
- Language
- ISSN
- 1932-4545
1940-9990
This paper presents a 288-pixel retinal prosthesis (RP) chip implemented in a 0.18 μm CMOS process. The proposed light-to-stimulus duration converter (LSDC) and biphasic stimulator generate a wide range of retinal stimuli proportional to the incident light intensity at a low supply voltage of 1V. The implemented chip shows 25.5 dB dynamic stimulation range and the state-of-the art low power consumption of 4.49 nW/pixel. Ex-vivo experiments were performed with a mouse retina and patch-clamp recording. The electrical artifact recorded by the patch electrode demonstrates that the proposed chip can generate electrical stimuli that have different pulse durations depending on the light intensity. Correspondingly, the spike counts in a retinal ganglion cell (RGC) were successfully modulated by the brightness of the light stimuli.