A fully-integrated high-compliance voltage SoC for epi-retinal and neural prostheses

Yi Kai Lo, Kuanfu Chen, Parag Gad, Wentai Liu

Research output: Contribution to journalArticlepeer-review

67 Citations (Scopus)

Abstract

This paper presents a fully functionally integrated 1024-channel mixed-mode and mixed-voltage system-on-a-chip (SoC) for epi-retinal and neural prostheses. Taking an AC input, an integrated power telemetry circuits is capable of generating multiple DC voltages with a voltage conversion efficiency of 83% at a load of 100 mW without external diodes or separate power integrated circuits, reducing the form factor of the prosthetic device. A wireless DPSK receiver with a novel noise reduction scheme supports a data rate of 2 Mb/s at a bit-error-rate of 2\,× 10 -7. The 1024-channel stimulator array meets an output compliance voltage of 10~V and provides flexible stimulation waveforms. Through chip-clustering, the stimulator array can be further expanded to 4096 channels. This SoC is designed and fabricated in TSMC 0.18 μm high-voltage 32 V CMOS process and occupies a chip area of 5.7 mm\,×, 6.6 mm. Using this SoC, a retinal implant bench-top test system is set up with real-time visual verification. In-vitro experiment conducted in artificial vitreous humor is designed and set-up to investigate stimulation waveforms for better visual resolution. In our in-vivo experiment, a hind-limb paralyzed rat with spinal cord transection and implanted chronic epidural electrodes has been shown to regain stepping and standing abilities using stimulus provided by the SoC.

Original languageEnglish
Article number6716090
Pages (from-to)761-772
Number of pages12
JournalIEEE transactions on biomedical circuits and systems
Volume7
Issue number6
DOIs
Publication statusPublished - 2013 Dec

All Science Journal Classification (ASJC) codes

  • Biomedical Engineering
  • Electrical and Electronic Engineering

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