Effectiveness of altered parameters of amplitude modulation-based haptic sensation generation (2023)
Undergraduate: Nita Prabhu
Faculty Advisor: Helen Huang
Department: Biomedical Engineering
Objective: Haptic sensation, commonly referred to as touch sensation, is used by individuals to receive information from their surroundings. Individuals using lower limb prosthetics are unable to receive haptic feedback, as amputation results in severed sensory nerves. A prominent use of haptic sensation generation is to restore sensation for lower limb amputees when walking or standing. While vibrational stimulation is typically used to generate haptic sensation, there is no standard stimulation paradigm. The purpose of this study is to assess the effectiveness of a modified amplitude modulation vibrational paradigm that incorporates a region of no stimulation, referred to as a dead band.
Approach: The study recruited 6 able-bodied participants. Each participant used a vest with embedded vibrational actuators to receive haptic sensations and completed a 1-dimensional tracing task. 3 stimulation paradigms with differing dead band sizes (none, small, large) were used. Participant accuracy, response time, and smoothness were used to assess effectiveness.
Findings: RMSE, lag, and jerk were calculated to assess subject response data. One statistically significant relationship (p = 0.0094) was found between stimulation paradigm and RMSE, indicating that amplitude modulation with a small dead band resulted in the most accurate position tracking.
Significance: This paper explored an alteration in current stimulation paradigms used in haptic feedback devices. Introducing a dead band to users provided an artificial reference point during experimentation that increased accuracy. Further work in assessing the dead band paradigm with more relevant applications can be used to best provide lower-limb amputees with information about their environment.