Exploring Embodiment and Usability of Autonomous Prosthetic Limbs through Virtual Reality

We propose the utilization of motion capture and immersive virtual reality to explore embodiment and user perception associated with prosthetic limbs. We developed a virtual reality simulation where a user could control an amputated avatar in first-person view with full body motion capture to experimentally investigate how the movement speed of an autonomous prosthetic limb affects its embodiment, usability, competence, warmth, and discomfort. In a within-subjects design experiment, participants performed a reaching task using a virtual prosthetic lower arm that moved at six different speeds in a minimum jerk trajectory. Results showed that extremely fast movements and extremely slow movements equally reduce embodiment, usability, and competence while movements at moderate speeds maximize embodiment and usability while reducing discomfort. Our findings provide insights into developing autonomous prosthetic limbs with higher user satisfaction that take embodiment, user perception, and usability into consideration.