NEC Seminar: Friday, October 4, 9:00 AM
In person in Sears 439
and via Zoom
Meeting ID: 928 0482 8495 Passcode: 185518
Speaker: Srikanth Chavali
Advisor: Prof. Hamid Charkhkar
Title: Bridging Neural Integration and Sensory Substitution for Improved Ankle Joint Sensation
Abstract: Individuals with lower limb loss experience significant balance deficits following their amputation. Amputees have a higher fall risk, contributing to low balance confidence and a greater fear of falling. A major contributing factor to this loss in balance stability is the lack of proprioceptive feedback in the missing limb. Proprioceptive sensation is the sensory modality that allows us to perceive the position and motion of our body parts. Commercial prosthetic systems currently lack the capability to provide proprioceptive sensation. Studies utilizing peripheral nerve stimulation through implanted electrode arrays have shown success in restoring plantar tactile sensation in individuals with lower limb loss, but has not been shown to be effective in restoring natural proprioception. The majority of studies that provide proprioceptive feedback to amputees utilize sensory substitution methods, providing feedback on movement through alternate modalities such as vibration. However, there is a significant cognitive load associated with sensory substitution and limited naturalness as users must associate unrelated sensations with movement. Preliminary work with an above knee amputee suggests that a sensory substitution approach to providing knee joint sensation can be more natural to the user when sensation is elicited in an expected location. By combining the traditional sensory substitution approach with direct nerve stimulation, we can preserve the functional benefits of sensory substitution while overcoming its typical limitations. Thus, I propose a method for providing ankle joint sensation by eliciting sensation that mimics stretch in the plantar fascia as it relates to gait. I will present a sensory stimulation paradigm as well as a proposed experiment that will test the ability of participants to classify associated stimulation patterns by the elicited sensation.