Neural Control of Cursor Trajectory and Click by a Human With Tetraplegia 1000 Days After Implant of an Intracortical Microelectrode Array
By Simeral, J.D.; Kim, S.-P.; Black, M.J.; Donoghue, J.P.; Hochberg, L.R.; Journal of Neural Engineering, Vol. 8, No. 2Publication Date: April 2011
Study assessed the feasibility of using neural activity obtained from the BrainGate to provide control signals for a neural prosthesis system. The BrainGate is described as a small scale, chronically implanted, intracortical array of 100 microelectrodes. The study sought to determine (1) how long implanted microelectrodes will record useful neural signals, (2) how reliably those signals can be acquired and decoded, and (3) how effectively they can be used to control various assistive technologies such as computers and robotic assistive devices. Neural cursor control and BrainGate system characteristics were assessed on 5 consecutive days, 1000 days after implant in the motor cortex of a 56 year old woman with tetraplegia caused by brainstem stroke. Time-amplitude sorting of neuronal spiking activity was performed. A population-based Kalman velocity decoding filter combined with a linear discriminant click state classifier was trained. Subsequently, closed-loop point-and-click cursor control was assessed. Participant performed both an 8 target center-out task and a random target Fitts metric task adapted from a human-computer interaction ISO standard used to quantify performance of computer input devices. The BrainGate system was further characterized by daily measurement of electode impedances, unit waveforms, and local field potentials. Across the 5 days, spiking signals were obtained from 41 of 96 electrodes and were successfully decoded to provide neural cursor point-and click control with a mean task performance of 91.3 percent correct target acquisition.
Published by: IOP Publishing Ltd (Website:http://www.iop.org/)
Link to text: http://iopscience.iop.org/1741-2552/8/2/025027
