ÐÇ¿Õ´«Ã½ BME Seminar
Focuss on Neural Engineering
Multimodal Imaging of the Human Vagus Nerve: Understanding the Functional Organization of Fascicles and Fibers
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Andrew Shoffstall, PhD
Assistant Professor
Department of Biomedical Engineering
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About Dr. Shoffstall:
Andrew Shoffstall is an Assistant Professor in Biomedical Engineering at ÐÇ¿Õ´«Ã½ in Cleveland. His research program focuses on the application of Biomaterials to develop Neural Interface technologies that address some of the challenges recognized in the field today: chronic stability, minimally invasive delivery, and translational/commercialization potential. Furthermore, to inform rational design of new electrodes and surgical approaches, he has recently also started to pursue improved imaging methods to elucidate the underlying functional anatomical organization of the vagus and other peripheral nerves. Dr. Shoffstall completed his postdoctoral training at ÐÇ¿Õ´«Ã½ and the VA Medical Center in Cleveland, OH, working with Jeff Capadona on various approaches to minimize the neuroinflammatory response to implanted intracortical recording microelectrodes. His PhD dissertation focused on the development of synthetic platelets to reduce bleeding after major trauma, including penetrating battlefield injuries, blast trauma, traumatic brain injury and spinal cord injury. Dr. Shoffstall spent a brief stint in industry as a Healthcare Strategy Consultant at the firm Health Advances (Boston, MA), where he worked on a wide range of commercial issues including: market forecasting, reimbursement & pricing, and mergers & acquisitions due-diligence. His experience in industry has greatly influenced his research interests and led him to co-found Neuronoff Inc., (alongside ÐÇ¿Õ´«Ã½ PhD graduate Manfred Franke, and University of Wisconsin Professor Kip Ludwig), a startup company which is developing a minimally invasive electrode to treat chronic pain.
Abstract:
The NIH SPARC REVA awardees will conduct multimodal, multiscale imaging of 100 human vagus nerves. Mapping the vagus nerve with the latest high resolution imaging modalities has tremendous potential to improve the safety and efficacy of existing therapies applied to the vagus nerve. By performing the most comprehensive imaging analysis of the human vagus nerve and its branches ever completed, and establishing a neuroanatomical repository for the vagus nerve, this work will seed and accelerate the development of novel neuromodulation therapies for autonomic regulation.
The vagus nerves connect to the brainstem and innervate most viscera, including the heart, airways, lungs, pancreas, and gastrointestinal tract. Given this widespread innervation, electrical stimulation of the vagus nerve offers therapeutic potential for many diseases: vagus nerve stimulation (VNS) has been applied to treat epilepsy, rheumatoid arthritis, and heart failure, among many other conditions. However, insufficient anatomical data are available to map the ~100,000 fibers of the human vagus nerve to their end organs for development of improved VNS therapies, with increased efficacy and decreased side effects. Our team will dissect 50 human cadavers and quantify the gross anatomy of their 100 vagus nerves (50 left, 50 right) with a 3D position sensor and with 3T MRI. We will quantify fascicle pathways along the whole nerve length with microCT. We will pioneer microscopy-based tractography of the vagus nerve with ultraviolet surface excitation (MUSE), a novel imaging technology developed at ÐÇ¿Õ´«Ã½. These multimodal, multiscale imaging data will be co-registered, segmented, visualized, and shared publicly. We will leverage these imaging data by validating and demonstrating their end-use in anatomically-realistic, biophysical, validated computational models of human vagus nerve stimulation.
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Stimulation of the Nerves and Cortex to Restore Sensory Function after Spinal Cord Injury
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Emily Graczyk, PhD
Assistant Professor
Department of Biomedical Engineering
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About Dr. Graczyk:
Emily Graczyk, PhD is an Assistant Professor in the Department of Biomedical Engineering at ÐÇ¿Õ´«Ã½ 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 ÐÇ¿Õ´«Ã½ in 2018, both in Biomedical Engineering. Dr. Graczyk’s primary research goal is to understand how to communicate effectively with the sensory nervous system to enable development of neuroprostheses to restore sensorimotor function to people with neurological injuries or disorders. 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 perceptual 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, autism spectrum disorder, and cancer.
Abstract:
In addition to having paralysis in all four limbs, most people with tetraplegia due to spinal cord injury (SCI) must also contend with loss of sensation below the level of injury. Because sensation is critical for dexterous object manipulation and social interactions with loved ones, loss of sensation can impair both upper extremity function and emotional wellbeing for people with SCI. Our goal is to develop sensory neurostimulation strategies to restore informative and intuitive sensation to people with SCI. When integrated into a brain computer interfacing (BCI) system to restore voluntary motor control, sensory neurostimulation could improve reaching and grasping function and increase social connection, leading to higher degrees of independence and quality of life for people with tetraplegia.
We are currently assessing the perceptual and functional benefits of several neurostimulation techniques in humans with tetraplegia enrolled in the Reconnecting the Hand and Arm to the Brain (ReHAB) clinical trial. We recently completed a study to directly compare perceived touch originating from stimuli applied to the person's own hand, intracortical microstimulation applied to primary somatosensory cortex, and peripheral nerve stimulation applied to the sensory nerves in the arm. We are also investigating the cortical representation of sensory information originating from both normal touch and electrical stimulation by recording from primary somatosensory cortex and other regions in the hand grasp network. Findings from this study will be used to design biomimetic stimulation paradigms that more closely reproduce natural neural activity, which could improve the perception and/or integration of these sensory inputs. The next step in this project is to implement sensory neurostimulation into closed-loop, BCI-controlled grasping to determine its impact on task performance. In future work, we plan to develop neurostimulation strategies to promote neuroplasticity in the residual sensory pathway, potentially enabling users to regain some of the sensory function that was lost due to SCI.