Design and Evaluation of User-Centered Extended Reality Myoelectric Prosthesis Training Tool.

In recent years, extended reality-based myoelectric training has emerged as a promising approach to prepare users for advanced prosthesis control. This study: 1) identified User Needs for an ideal training tool through qualitative interviews with occupational therapists; 2) developed the Myoelectric Training in Extended Reality (MyoTrainXR) system; and 3) evaluated its usability using an advanced postural control strategy. Six individuals with intact limbs and two with trans-radial upper limb loss underwent four 45-minute training sessions with the Block Builder module. The Pasta Box Task was used during training and evaluation, and the Cup Transfer Task was used only during evaluation. In the Pasta Box Task, participants with intact limbs maintained a 100% completion rate, while their success rate increased from $86.1\pm 5.8$ % to $98.5\pm 3.7$ %. Participants with upper limb loss began with completion rates between 0% and 40%, improving to 100%, with success rates between 90.9% and 100% by the final evaluation. Iteration completion times showed significant reduction across all participants ( $p$ -value < 0.05, linear mixed-effects model), with the median decreasing from 19.4 to 15.8 seconds. The Cup Transfer Task showed a similar trend of significant improvement, demonstrating that the acquired skills generalized to an untrained task. The system also demonstrated excellent usability, with an average System Usability Scale score of $81.9\pm 10.0$ . These findings indicate that our user-centered extended reality training tool holds promise for enhancing myoelectric control proficiency.