Achievements and challenges of translational research in non-invasive SMR-BCI-controlled upper extremity neuroprosthesis in spinal cord injury

An injury of the upper cervical spinal cord and the associated paralysis of the lower and upper extremities is one of the most dramatic events that can happen in a life of a human being. If the hand function is complete lost, neuroprostheses on the basis of functional electrical stimulation (FES) represent the only possibility for restoration of basic grasp patterns. Non-invasive electroencephalogram (EEG)-based Brain Computer Interfaces (BCIs) are an emerging technology that may provide the possibility for intuitive operation of a multi-degree of freedom upper extremity neuroprosthesis. Although evidence from studies with able-bodied subjects and a few end users with SCI is available about the basic feasibility of BCI-controlled grasping and reaching neuroprostheses, it is still unknown, in how far these results can be generalized. The aim of this paper is to provide an overview of the achievements in translation of basic research results to real-world application in people with high cervical SCI and to outline future challenges.