A programmable discharge circuitry with current limiting capability for a retinal prosthesis

Mohanasankar Sivaprakasam, Wentai Liu, Guoxing Wang, James D. Weiland, Mark S. Humayun

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Biphasic stimulation is the most commonly used electrical pattern in FES (Functional Electrical Stimulation). In such cases, a charge balanced waveform is essential to prevent any charge accumulation in the biological tissue. In a retinal prosthesis, a charge cancellation circuitry is used to discharge the stimulation sites on the retina periodically to ensure tissue safety. But discharging a node that has high voltage (due to charge accumulation) will induce large currents that might lead to unintended stimulation of the retina. This paper presents a new discharge circuitry which can act as a simple resistive discharge path for smaller voltages and a current limiter for higher voltages. In stimulation circuits which use a dual voltage scheme (positive and negative), the circuit limits the current at both polarities. The discharge profile is programmable digitally. In addition, a method to characterize inter-pixel leakage in a retinal prosthesis using this circuit is proposed.

Original languageEnglish
Title of host publicationProceedings of the 2005 27th Annual International Conference of the Engineering in Medicine and Biology Society, IEEE-EMBS 2005
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages5234-5237
Number of pages4
ISBN (Print)0780387406, 9780780387409
DOIs
Publication statusPublished - 2005
Event2005 27th Annual International Conference of the Engineering in Medicine and Biology Society, IEEE-EMBS 2005 - Shanghai, China
Duration: 2005 Sept 12005 Sept 4

Publication series

NameAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
Volume7 VOLS
ISSN (Print)0589-1019

Other

Other2005 27th Annual International Conference of the Engineering in Medicine and Biology Society, IEEE-EMBS 2005
Country/TerritoryChina
CityShanghai
Period05-09-0105-09-04

All Science Journal Classification (ASJC) codes

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics

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