Neuroengineering & Medicine Seminar: Restoring Sensation with Peripheral and Cortical Neurostimulation in Bidirectional Neuroprostheses

Tactile and proprioceptive sensation in the hand and arm are critical for grasp regulation, dexterous object manipulation, and social interactions with loved ones. For people with spinal cord injury and upper limb amputation, loss of sensation can impair both upper extremity function and emotional wellbeing. My lab develops sensory neurostimulation strategies to restore informative and intuitive sensation to people with sensory deficits. In early feasibility clinical trials, we integrate sensory feedback from chronically-implanted nerve and intracortical interfaces into bidirectional neuroprosthetic systems to improve functional and psychological outcomes. In this seminar, I will describe our recent studies investigating the perception and cortical representation of sensory neurostimulation in participants with amputation and spinal cord injury. I will present our progress towards developing and assessing novel biomimetic stimulation paradigms for touch and proprioception, which reproduce aspects of natural neural activity to improve the experience and utility of the artificial sensation. I will also present our work investigating peripheral nerve stimulation as a sensory feedback modality in participants with sensory-incomplete spinal cord injury for the first time. In this work, we compared the perceived sensations arising from peripheral nerve stimulation, intracortical microstimulation, and touch applied to the participant's own hand, and also examined the neural activity resulting from nerve stimulation in primary somatosensory cortex. Finally, I will describe an upcoming clinical trial of twelve upper limb prosthesis users that seeks to understand the benefits of restoring sensation and intuitive control to an advanced prosthesis via a fully-implanted neuroprosthetic system.

 

Emily Graczyk, PhD is an Assistant Professor in the Department of Biomedical Engineering at Case Western Reserve University and an Investigator in the Functional Electrical Stimulation Center at the Louis Stokes Cleveland VA Medical Center. She earned her BS at the University of South Carolina, Columbia in 2013 and her PhD at Case Western Reserve University in 2018, both in Biomedical Engineering. Dr. Graczyk’s primary research goal is to develop neuroprostheses to restore sensorimotor function to people with neurological injuries or disorders. Her work also aims to improve our understanding of how to communicate effectively with the sensory nervous system with neurostimulation. Her lab uses neural stimulation and recording techniques in the periphery and cortex of human participants to investigate sensory neural coding, sensorimotor integration and learning, and the experience of sensation created by neurotechnology. Her lab also uses multidisciplinary approaches to understand the needs and perspectives of neuroprosthesis users and to assess clinical outcomes. Dr. Graczyk's current projects focus on restoring sensation to people with amputation, spinal cord injury, and breast cancer.