A chronic generalized bi-directional brain–machine interface

Abstract

A bi-directional neural interface (NI) system was designed and built by incorporating a novel neural recording and processing subsystem into a commercially approved neural stimulator. The NI system prototype leverages the system infrastructure from a market-approved neurostimulator to ensure reliable operation in a chronic implantation environment. In addition to providing approved therapy capabilities, the device adds key elements to facilitate chronic clinical research, such as four channels of ECoG/LFP amplification and spectral analysis, a three axis accelerometer, algorithm processing, event-based data logging, and wireless telemetry for data uploads and algorithm/configuration updates. The custom integrated micropower sensor and interface circuits facilitate extended operation in a power-limited device. The prototype underwent significant verification testing to ensure reliability, and meets the requirements for a class CF instrument per IEC-60601 protocols. The ability of the device system to process and aid in classifying brain states was preclinically validated using an in-vivo non-human primate model for brain control of a computer cursor (i.e., brain machine interface or BMI). The primate BMI model was chosen for its ability to quantitatively measure signal decoding performance from brain activity that is similar in both amplitude and spectral content to other biomarkers used to detect disease states (e.g. Parkinson’s). A key goal of this research prototype is to help broaden the clinical scope and acceptance of NI techniques, particularly real-time brain state detection. These techniques can be generalized beyond motor prosthesis, to include significant unmet needs in other neurological conditions such as movement disorders, stroke, and epilepsy.

Long-Term Surface Electrode Impedance Recordings Associated with Gliosis for a Closed-Loop Neurostimulation Device

“…For example, using a scaled down DBS electrode in a primate model electrical stimulation resulted in a significant but reversible decrease in impedance magnitude. Electrical impedance changes as a result of electrical stimulation have also been documented in humans with cochlear implants [29,30].…”

Silicon-Integrated High-Density Electrocortical Interfaces

“…(b) NeuroVista seizure advisory system [111], [152], [153]. (c) The neural interface (NI) system of Medtronic [154], [155]. (d) The Wireless Implantable Multi-channel Acquisition system for Generic Interface with NEurons (WIMAGINE) [122].…”

A Parametric Simulation of Neuronal Noise From Microelectrode Recordings

“…DBS involves applying a pulsed electric field to a deep brain structure with an electrode positioned to within 1 mm accuracy. DBS applies chronic stimulation, using no feedback based on the patient's state, except for occasional clinical adjustment [25]. The subthalamic nucleus (STN) is a common target for the treatment of PD [6].…”

“…Models of the STN may help further the understanding of DBS and in vivo neuronal activity in general. Improving the understanding of the role of the STN in DBS could benefit future stimulation therapies, including development of a closed-loop DBS strategy [25].…”

“…This model may also have use as an aid in confirmation of target volumes for DBS. In addition realtime adaptations of STN models are required for a feedback controller for DBS [25].…”