A system for efficient neural stimulation with energy recovery

An analog VLSI-based low-power neural tissue stimulator is presented as a part of the MIT and Massachusetts Eye and Ear Infirmary Retinal Implant Project to develop a prosthesis for restoring some useful vision to patients blinded by retinal degeneration. Such a prosthesis would receive image data from an external camera and electrically stimulate surviving ganglion nerve cells. However, power consumption for this type of implant is dominated by the tissue and electrode-tissue interface, and the current source stimulators generally used are inefficient, limiting battery life and generating potentially damaging temperature increases at the retinal surface. A stimulation system has been developed which delivers the required stimulus charge to the electrodes, but uses far less power than typical stimulators. A traditional current source uses output transistors to limit current, but those transistors can drop substantial voltage, and therefore cost power. The aim of this system is to generate a step-ramp voltage waveform which mimics the electrode voltage (modeled as a series resistance and capacitance) during constant current stimulation. This is implemented with a series of voltage steps, each step a separate power supply.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Kelly, Shawn Kevin, 1973-

Advisor dc:contributor.advisor

• John L. Wyatt, Jr.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/30084

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/30084