NEC Friday Morning Seminar
Speaker: Rachel Jakes
Advisor: Prof. Dustin Tyler
Title: RhCh Recruitment: Modulating PNS Percepts through Strength-Duration Curves
Abstract:
Peripheral nerve stimulation (PNS) has the ability to evoke the sense of touch and is used in applications ranging from sensory restoration for people with limb loss to haptic feedback for extended reality. PNS is operated in a complex stimulation parameter space to modulate percept characteristics such as location and intensity. However, it is difficult and time-consuming to comprehensively map this parameter space to specific perceptual outcomes, as neural recruitment patterns and bounds are dependent on all the parameters in the space. As a result, PNS modulating a single variable is unable to capture a diverse portion of the perceptual space.
As an alternative to single-variable modulation, strength-duration curves relate two stimulation parameters, pulse width and pulse amplitude, to tissue excitation. Strength-duration curves can be fully described by two values: a rheobase, and a chronaxie. In sensory PNS, minimum intensity perceptual thresholds have been shown to follow a strength-duration curve. We hypothesize that strength-duration curves can also describe perceptual "iso-intensity" curves throughout the dynamic intensity range. Further, by determining the rheobase and chronaxie of these perceptual intensity curves, we hypothesize that the full perceptual dynamic intensity range can be quickly characterized in two stimulation parameter dimensions, enabling more efficient modulation of location, intensity, and quality. This talk will explore the potential of a rheobase-chronaxie (RhCh) based neural recruitment scheme and present preliminary data defining perceptual strength duration curves across the dynamic intensity range.