Date(s) - 02/25/2014
Direct interfacing of micro-devices with the brain has the potential to revolutionize the medical treatment of many neurological diseases or injuries. Unfortunately, chronic implantation of neural micro-devices is followed by a reactive tissue response that both functionally isolates the device from the tissue as well as triggers neuronal apoptosis or migration. The tissue response presents a fundamental obstacle to the design of neuroprostheses. Previous research has shown that the tissue responds to: 1) the initial device insertion, 2) the device indwelling, and 3) the application of the electrical stimulation. The goal of our ongoing research is to understand and mitigate this tissue response, thus enabling the development of multi-channel neural microstimulation for clinical therapy. This development is based on a central framework that multi-channel microstimulation will be a more effective treatment than low-channel count macrostimulation (e.g. deep-brain stimulation). In particular, our primary research objective is to determine the dual-effects of repeated stimulation and the reactive tissue response on the efficacy of stimulation-evoked behavior. To this end, we conduct psychophysical experiments using multi-channel cortical implants in the auditory and somatosensory cortex of rats. Furthermore, we collect longitudinal electrochemical and electrophysiological data via the implanted devices. Finally, we investigate several chemically- and electrically-based tissue-response mitigation strategies. Here we report the results of these various experiments and their implications for reliable chronic neural stimulation via micro-devices. We expect that these data will enable further neuroprosthetic development for many potential applications of microstimulation.
Dr. Kevin J. Otto received the B.S. degree in chemical engineering from Colorado State University in 1997, the M.S. degree in Bioengineering in 2002 and the Ph.D. Degree in Bioengineering in 2003 from Arizona State University, Tempe.
From 1997 to 2003 he was a Research Assistant in the Bioengineering Department, Arizona State University, where his work was in the areas of neural engineering and sensory neuroprostheses. From 2003 to 2004 he was a Research Fellow in the Department of Biomedical Engineering, University of Michigan, Ann Arbor where his work focused on brain-machine interface systems and implantable devices. From 2004 to 2006 he was a Post-Doctoral Fellow in the Central Systems Laboratory in the Kresge Hearing Research Institute in the Department of Otolaryngology at the University of Michigan, Ann Arbor where his work focused on cochlear implants.
He is currently an Associate Professor in the Department of Biological Sciences and Biomedical Engineering at Purdue University. His research interests include neuroprostheses, systems neuroscience, and neurotechnologies.