(Invited) Reanimating Paralyzed Limbs and the Future of Bioelectronic Medicine

Abstract

Millions suffer from diseases and injuries that lead to paralysis through disruption of signal pathways between the brain and the muscles. Bioelectronic devices are designed to restore lost function and can be used to form an electronic ‘neural bypass’ to circumvent disconnected pathways in the nervous system. Intracortically-recorded signals have been decoded to produce information related to motion allowing non-human primates and paralyzed humans to control computers and robotic arms through imagined movements. In a first-in-human clinical study, it has been shown that intracortically-recorded signals can be linked in real-time to muscle activation to restore movement in a paralyzed human. Machine-learning algorithms were developed to decode the neuronal activity and control electrical stimulation of the participant’s forearm muscles through a custom-built high-resolution neuromuscular electrical stimulation system. The system allowed the participant to achieve isolated finger movements and continuous cortical control of six different wrist and hand motions. Furthermore, the participant completed functional tasks relevant to daily living. Clinical assessment showed that when using the system, the participant’s motor impairment level improved from C5-C6 to a C7-T1 level unilaterally, giving him the critical abilities to grasp, manipulate and release objects. This was the first demonstration of successful control of muscle contraction utilizing intracortically-recorded signals in a paralyzed human. These results have significant implications in advancing bioelectronic technology for the millions of people worldwide living with paralysis. Future work will include developing improved machine learning algorithms and high-resolution implantable neural interface technology to support highly dexterous movement in the hand and movement in the lower extremities. Also, decoding methods are being developed for peripheral nervous system signals for extraction of important biomarkers for the diagnosis and treatment of a wide variety of diseases and conditions.