Constant-Current Adjustable-Waveform Microstimulator for an Implantable Hybrid Neural Prosthesis

• Published in: 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society Vol. 2007; pp. 2436 - 2439
• Main Authors: Hassell, T.J., Jedlicka, S.S., Rickus, J.L., Irazoqui, P.P.
• Format: Conference Proceeding Journal Article
• Language: English
• Published: United States IEEE 01.01.2007
• Subjects: Bionics; Chirp modulation; Computer-Aided Design; Control systems; Electric Impedance; Electric Stimulation - instrumentation; Electric Stimulation - methods; Electric Stimulation Therapy; Electrodes; Electrodes, Implanted; Electronics, Medical - instrumentation; Electronics, Medical - methods; Epilepsy; Equipment Design; Humans; In vitro; Microcomputers; Miniaturization; Nervous system; Parkinson's disease; Pharmaceuticals; Printed circuits; Prostheses and Implants; Prosthesis Design; Prosthetics; Prototypes; Transistors, Electronic
• DOI: 10.1109/IEMBS.2007.4352820
• ISBN: 9781424407873; 1424407877
• ISSN: 1094-687X; 1557-170X

Microstimulation of neural tissue has become a widely-used technique for controlling neuronal responses with local electric fields as well as a therapeutic intervention for nervous system disorders such as epilepsy and Parkinson's disease. Of those afflicted by neurological diseases, many are or become tolerant to existing pharmaceuticals and are left with little recourse. Little is known about the necessary design criteria or efficacy of a hybrid neural prosthesis. Assessment of the potential clinical value of a hybrid electro-chemical neural prosthesis was performed through in vitro verification using a prototype microstimulator and P19 cell cultures. We constructed a printed circuit board (PCB) microstimulator as a prototype of a CMOS microstimulator ASIC that was subsequently fabricated in the IBM 7RF 0.18 mum process. Measured results for the prototype are described in this work. An output impedance of 237 kOmega, voltage compliance of 11.3 V, and a linear constant-current output up to +/-600 muA make this microstimulator system a viable option for an implantable hybrid neural prosthesis. Hybrid prostheses could uniquely affect neural modulation with linear glutamate release at physiological amplitudes and frequencies.