NEC Seminar: Friday, July 26, 9:00 AM
Location: Wickenden 321
Speaker: Bhanu Prasad Kotamraju
Advisor: Prof. D. Durand
Title: Selective neural recordings in small nerve fascicles with carbon nanotube yarns
Abstract:
The primary challenge in neural rehabilitation engineering is the current technological limitation in matching the complexity of neural tissue, which hampers selective recordings from multiple fascicles across different nerves. The ability to chronically and safely record from multiple fascicles simultaneously could significantly impact the fields of neural and rehabilitation engineering.
Previous research has indicated that Carbon Nanotube Yarns (CNTYs) are capable of recording from autonomic nerves with small diameters (100-300µm), making them a promising candidate for this study.
The first part of this presentation examines the chronic recording capabilities of CNTYs. Electrodes were implanted into three individual fascicles of the sciatic nerve in rats, and their neural activity during gait was recorded. Analysis using information theory revealed superior recording capabilities compared to cuff electrodes, demonstrating the stability and selectivity of these recordings. However, a challenge remains with these electrodes due to their single-channel configuration, which complicates the development of a high-density interface capable of handling nerves with numerous fascicles (previous studies were limited to a maximum of 3 fascicles).
Building on these findings, the second part of the presentation introduces results from a feasibility study aimed at overcoming this limitation. A novel interfacing technique using CNTY electrodes enabled a high-density nerve interface. To validate this approach, electrodes were implanted into seven fascicles of a pig median nerve, recording neural responses to various sensory stimuli such as vibration, proprioception, and temperature. This study demonstrates the potential to achieve selective fascicular recordings in nerves with multiple fascicles, thereby showcasing the efficacy and promise of the new interface.