Abstract
Defining eloquent cortex intraoperatively, traditionally performed by neurosurgeons to preserve patient function, can now help target electrode implantation for restoring function. Brain-machine interfaces (BMIs) have the potential to restore upper-limb motor control to paralyzed patients but require accurate placement of recording and stimulating electrodes to enable functional control of a prosthetic limb. Beyond motor decoding from recording arrays, precise placement of stimulating electrodes in cortical areas associated with finger and fingertip sensations allows for the delivery of sensory feedback that could improve dexterous control of prosthetic hands. In our study, we demonstrated the use of a novel intraoperative online functional mapping (OFM) technique with high-density electrocorticography (ECoG) to localize finger representations in human primary somatosensory cortex. In conjunction with traditional pre- and intraoperative targeting approaches, this technique enabled accurate implantation of stimulating microelectrodes, which was confirmed by post-implantation intra-cortical stimulation of finger and fingertip sensations. This work demonstrates the utility of intraoperative OFM and will inform future studies of closed-loop BMIs in humans.
Competing Interest Statement
The authors have declared no competing interest.
Clinical Trial
NCT03161067
Funding Statement
This research was developed with funding from the Defense Advanced Research Projects Agency's (DARPA, Arlington) Revolutionizing Prosthetics program (contract number N66001-10-C-4056). The views, opinions, and/or findings expressed are those of the author(s) and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government. Development of experimental setup and support for regulatory submissions associated with this study were provided by a grant from the Alfred E. Mann Foundation. Study software infrastructure and study preparation were developed with internal funding from Johns Hopkins University Applied Physics Laboratory and Johns Hopkins University. Personnel was also supported by NIH (R01NS088606).
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
This study was conducted under Investigational Device Exemption (IDE, 170010) by the Food and Drug Administration (FDA) for the purpose of evaluating bilateral sensory and motor capabilities of microelectrode array implants. The study protocol was approved by the FDA, the Johns Hopkins Institutional Review Board (JH IRB) and NIWC Pacific IRB.
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Data Availability
Data is available upon request.