Abstract - The long-term goal of this research is to improve sensory feedback in neuroprostheses by optimizing electrical stimulation parameters to enhance user experience and control. Over 85,000 people in the U.S. experience upper limb loss annually, many abandoning their prosthesis due to a lack of sensory feedback. Electrical stimulation shows promise in addressing this, with prior work indicating that varying stimulation parameters can modulate sensation intensity.

This study shows that changes in signal amplitude elicit stronger perceived magnitude responses than frequency changes, providing insights for better utilization of stimulation feedback. Participants perceived amplitude changes more intensely than frequency, with slopes for amplitude being more than twice as steep (slope_amp = 17.74, slope_freq = 8.04), a statistically significant result (p < 0.05). The electrode-tissue interface was modeled as a parallel RC circuit with a resistance of 32 kΩ and capacitance of 11.89 nF. These findings could inform the design of more responsive prosthetic devices and other medical systems that use electrical stimulation.