Wireless Sub-Cellular Sized Stimulators for Minimally Invasive Deep Brain Stimulation with High Spatiotemporal Resolution

Abstract

Deep brain stimulation (DBS) has become a mainstream treatment for motor disorders associated with neurodegenerative conditions such as Parkinson’s disease (PD). The DBS device, often called the “pacemaker for the brain”, utilizes surgically implanted leads with 4-8 contacts points into the targeting area. The implanted electrodes are then used to deliver high frequency (>85 Hz) electrical stimulation via a pulse generator. In properly selected patients, DBS is proven to be remarkably effective, alleviating motor symptoms that either do not fully respond to medication treatment (such as tremor) or are caused by it (levodopa-induced dyskinesia). However, current DBS technology comes with inherent limitations and problems, including: 1) the need of a large invasive foreign body (the electrode) which can cause lead infections, 2) low coverage of entire movement-related territory in the target nucleus, and 3) adverse side effects such as muscle twitches and sensory complaints caused by diffused current into the tissues.

In this work, we propose to develop a new paradigm of electrical neuromodulation, based on injectable micron-sized stimulator devices, which, once deployed, will allow tunable stimulation of the injected territory. The individual stimulators will produce highly localized stimulation effects, which will minimize current spread to neighboring structures. Since the stimulator devices will be activated from an super-low-frequency (SLF) external magnetic field source, the procedure would not require placement of permanent wired leads in the brain. Additionally, given that a lightweight low-power wearable coil array will power the stimulator devices, a continuous portable DBS treatment of Parkinson's disease will be unprecedentedly made possible.