Closed Loop Deep Brain Stimulation
Artin Petrossians, PhD
Thursday, June 22nd 2017, 7:30 pm
Armenian Society of LA
117 S. Louise Street, Glendale, CA 91205
Reliable and efficient bio-electronic brain interfaces are needed for an increasing number of clinical neuro-modulation therapies. Deep brain stimulation (DBS) therapy is a clinically accepted technique for treatment of movement disorders. DBS involves implanting a battery powered, electrical pulse-generator underneath the clavicle, tunneling a lead wire to the top of the skull, and inserting, through a craniotomy, a linear electrode array deep into the brain. Continuous electrical stimulation of basal ganglia or thalamus has been shown to decrease the symptoms of movement disorders such as Parkinson’s disease and essential tremor. DBS therapy is expanding to a multitude of neurological disorders. More generally, microelectronic implants are used to treat deafness, chronic pain, and depression. Obesity, memory loss, blindness, and migraine are emerging targets for implants. Implants can also record neural activity for controlling artificial limbs and detecting epileptic activity. Electrodes are the functional interface between these devices and neural tissue. Inefficient electrode materials are a critical barrier to progress in the field of DBS and electronic implants in general, particularly as the field moves towards more electrodes per device, smaller electrode sizes, and closed feedback systems. The requirement for more electrodes per device is motivating medical device companies to adopt micro-fabricated arrays, since these can reliably and consistently achieve dozens of individual contacts densely packed on single substrate. However, due to poor metal film quality, electrode sites on such devices dissolve under conditions of long-term stimulation, even at charge density levels considered electrochemically safe.
An improved electrode material will have a significant impact on the capabilities of the devices and the effectiveness of treatment by enabling the use of micro-fabricated electrodes for chronic stimulation at higher charge density and by reducing stimulus artifact and increasing signal to noise ratio of bio-potentials, thus improving detection of important biomarkers needed for closed loop stimulation strategies.
Dr. Artin Petrossians obtained his Ph.D. in 2012 from the Mork Family Department of Chemical Engineering and Materials Science, University of Southern California. He is currently an adjunct assistant professor at the Department of Ophthalmology, University of Southern California, principal investigator (PI), co-founder and chief technology officer (CTO) at Platinum Group Coatings, LLC. Dr. Petrossians’ research field is focused on the performance of brain implants and optimization of signals on the brain/machine interfaces. His current research is directed to investigate the neural activities in Parkinsonian mice, rats and monkeys’ brains by using high-performance implantable electrode materials.