Research

People with lower-limb amputations lose sensory feedback from their foot, contributing to a higher rate of falls. Furthermore, phantom limb pain affects more than 70% of people with limb amputations. Transcutaneous spinal cord stimulation (tSCS) is a non-invasive neuromodulation method that excites dorsal spinal roots and reflex pathways. We use tSCS to restore sensations in the missing foot of people with a transtibial amputation. We evoke sensations in the foot during walking to improve balance and gait stability. We also determine how tSCS can alter spinal networks and reduce phantom limb pain.

Spinal cord stimulation (SCS) can improve motor recovery following complete and incomplete spinal cord injury (SCI). One limiting factor to the clinical translation of SCS for the recovery of walking is the requirement for manual selection of electrodes and programming of stimulation parameters. We use machine learning to search through the electrodes and stimulation parameters to determine the settings required for optimal activation of the leg muscles for the restoration of walking after SCI.

Navigating changing of terrain, such as transiting between even surfaces to curbs, stairs, and uneven surfaces, is challenging for people who have suffered a stroke. We aim to use reinforcement learning to predict signals from body-worn sensors (such as forces, joint angles, and muscle activity) to determine when these terrain transitions are about to happen. We plan to use these predictions as input signals for an exoskeleton to assist the person as needed while navigating these difficult terrain transitions.

Novel neural interfaces and materials must be tested in chronic in vivo models prior to translation to human implants. Through partnerships with companies and other research groups, we perform preclinical testing of devices and materials with the goal of translating the neurotechnologies to use in humans. We also use these devices and materials to investigate the mechanisms of different neuromodulation methods and how the body reacts to implanted neural interfaces.

Spinal cord stimulation (SCS) has been shown to improve motor recovery following chronic spinal cord injury (SCI) in animal models and humans. What is unknown is if modulating the spinal cord following acute SCI could lead to improved motor recovery and a reduction in secondary complications, such as spasticity or neuropathic pain. We aim to determine the optimal timing of SCS after SCI in rodent models, which will inform on the therapeutic applications of SCS for humans.