Point-and-click cursor control with an intracortical neural interface system by humans with tetraplegia

IEEE Trans Neural Syst Rehabil Eng. 2011 Apr;19(2):193-203. doi: 10.1109/TNSRE.2011.2107750. Epub 2011 Jan 28.

Abstract

We present a point-and-click intracortical neural interface system (NIS) that enables humans with tetraplegia to volitionally move a 2-D computer cursor in any desired direction on a computer screen, hold it still, and click on the area of interest. This direct brain-computer interface extracts both discrete (click) and continuous (cursor velocity) signals from a single small population of neurons in human motor cortex. A key component of this system is a multi-state probabilistic decoding algorithm that simultaneously decodes neural spiking activity of a small population of neurons and outputs either a click signal or the velocity of the cursor. The algorithm combines a linear classifier, which determines whether the user is intending to click or move the cursor, with a Kalman filter that translates the neural population activity into cursor velocity. We present a paradigm for training the multi-state decoding algorithm using neural activity observed during imagined actions. Two human participants with tetraplegia (paralysis of the four limbs) performed a closed-loop radial target acquisition task using the point-and-click NIS over multiple sessions. We quantified point-and-click performance using various human-computer interaction measurements for pointing devices. We found that participants could control the cursor motion and click on specified targets with a small error rate (< 3% in one participant). This study suggests that signals from a small ensemble of motor cortical neurons (∼40) can be used for natural point-and-click 2-D cursor control of a personal computer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Algorithms
  • Amyotrophic Lateral Sclerosis / complications
  • Feedback, Psychological
  • Female
  • Humans
  • Intention
  • Learning
  • Male
  • Middle Aged
  • Models, Neurological
  • Models, Statistical
  • Motor Cortex / cytology
  • Motor Cortex / physiology*
  • Neurons / physiology
  • Psychomotor Performance / physiology
  • Quadriplegia* / etiology
  • Stroke / complications
  • User-Computer Interface*