Decoding hand and wrist movement intention from chronic stroke survivors with hemiparesis using a wearable neural interface

Prosthetics and orthotics have been recognized for decades as a potential means to restore hand function and independence to individuals living with impairment due to stroke. However, 75% of stroke survivors, caregivers, and health care professionals (HCP) believe current practices are insufficient, specifically calling out upper extremity as an area where innovation is needed to develop highly usable prosthetics/orthotics for the stroke population. A promising method for controlling upper limb prosthetics is to infer movement intent non-invasively from electromyography (EMG) activity. While this approach has garnered significant attention in the literature, existing technologies are often limited to research settings and struggle to meet stated user needs. To address these limitations, we have developed the NeuroLife(R) EMG System which consists of a wearable garment, similar to a compression sleeve, worn on the forearm with 150 embedded electrodes spread across the forearm, and associated hardware and software to record and decode high-resolution surface EMG. We demonstrate that the NeuroLife EMG System can accurately decode 12 functional hand, wrist, and forearm movements, including multiple types of grasps from participants with varying levels of impairment, with an overall accuracy of 77.1{+/-}5.6% in ideal scenarios and 74.7{+/-}5.0% in simulated real-time situations. Importantly, we demonstrate the ability to decode movements that participants are unable to overtly perform, showing potential as a control mechanism for assistive technologies. Feedback from stroke survivors who tested the system indicates that the design of the sleeve meets various user needs including being comfortable, portable, and lightweight. The sleeve is in a form factor such that it can be used at home without an expert technician, can be donned with the help of a caretaker, and can be worn for multiple hours without discomfort. Taken together, the NeuroLife EMG System represents a platform technology to record and decode high-definition electromyography for the real-time control of assistive devices in a form factor designed to meet user needs.