Adaptive Offset Correction for Intracortical Brain Computer Interfaces




Intracortical brain computer interfaces (iBCIs) decode intended movement from neural activity for the control of external devices such as a robotic arm. Standard approaches include a calibration phase to estimate decoding parameters. During iBCI operation, the statistical properties of the neural activity can depart from those observed during calibration, sometimes hindering a user’s ability to control the iBCI. To address this problem, we adaptively correct the offset terms within a Kalman filter decoder via penalized maximum likelihood estimation. The approach can handle rapid shifts in neural signal behavior (on the order of seconds) and requires no knowledge of the intended movement. The algorithm, called MOCA, was tested using simulated neural activity and evaluated retrospectively using data collected from two people with tetraplegia operating an iBCI. In 19 clinical research test cases, where a nonadaptive Kalman filter yielded relatively high decoding errors, MOCA significantly reduced these errors (10.6 ± 10.1\%; p < 0.05, pairwise t-test). MOCA did not significantly change the error in the remaining 23 cases where a nonadaptive Kalman filter already performed well. These results suggest that MOCA provides more robust decoding than the standard Kalman filter for iBCIs.

Author(s): Mark L. Homer and J’anos A. Perge and Michael J. Black and Matthew T. Harrison and Sydney S. Cash and Leigh R. Hochberg
Journal: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Volume: 22
Number (issue): 2
Pages: 239--248
Year: 2014
Month: March

Department(s): Perceiving Systems
Research Project(s): Neural Prosthetics and Decoding
Bibtex Type: Article (article)
Paper Type: Journal


Links: pdf


  title = {Adaptive Offset Correction for Intracortical Brain Computer Interfaces},
  author = {Homer, Mark L. and Perge, J'{a}nos A. and Black, Michael J. and Harrison, Matthew T. and Cash, Sydney S. and Hochberg, Leigh R.},
  journal = {IEEE Transactions on Neural Systems and Rehabilitation Engineering},
  volume = {22},
  number = {2},
  pages = {239--248},
  month = mar,
  year = {2014},
  month_numeric = {3}