During the advanced stages of hand prosthesis training, amputees strive to perfect their movements to enhance fine motor skills, increase speed, and achieve fluid and continuous actions. However, this training typically occurs in abstract, low-engagement scenarios, limited to practicing unilateral hand motions generally without wearing the prosthesis and lacking kinematic performance assessment. We propose a gamified Mixed-Reality (MR) system that allows amputees to practice controlling their actual prosthesis while observing their movements and task performance within a semi-immersive, realistic, and engaging environment. A notable aspect of this system is the ability to facilitate safe practice of grasping maneuvers, supporting both unilateral training and complex bilateral coordination. Ten healthy subjects completed trials involving manipulating virtual objects within an MR environment, establishing ground truth metrics with their collected data. Subsequently, two users with prosthetic hands tested the system, providing initial insights into its applicability for rehabilitation purposes. Performance outcomes and user feedback were analyzed to assess the system’s usability and effectiveness in fostering hand movements and overall user experience. Both participant groups rated the MR training system highly positive; all User Experience Questionnaire (UEQ) factor mean scores (Pragmatic, Hedonic, and Attractiveness) exceeded the $$+1.0$$ threshold. The reference metrics obtained from non-amputee (NA) participants were significant in assessing the quality of movements and performance of amputees in both unilateral and bimanual hand use. Notably, compared to the NA group, prosthetic users exhibited significantly poorer unimanual performance, requiring 90% more time, covering 50% greater distance, and showing 15% reduced smoothness, yet demonstrated equivalent performance during bimanual tasks. Collectively, these findings validate the system’s utility, demonstrating its potential as an innovative and engaging tool for advancing unimanual and bimanual prosthetic training. By providing an opportunity to train with the actual prosthesis, this approach aims to promote more effective skill transfer. The reference metrics generated by NA users, including time, distance, position error, peak velocity, smoothness, and fingertip span, will serve as a benchmark to evaluate prosthesis control and assess the functional progress of amputee users.

Nowadays, upper limb prosthesis acceptance remains low due to ineffective control techniques and the relative training methods. However, an engaging training method applied during early prosthetic fitting seems to have a positive impact on acceptance. To this aim, in this paper we present a Mixed Reality (MR) pre-fitting training system based on Microsoft HoloLens2, designed for users of the Hannes prosthetic hand. The system allows individuals with varying stump morphologies to control a holographic Hannes hand through a low-latency interface, replicating the physical architecture and motion of the real device in an immersive, portable environment. This pilot study presents the preliminary evaluation of the MR framework conducted with two limb difference participants (one naïve user and one experienced user in myoelectric prosthesis control) performing a novel bimanual Target Achievement Control (TAC) test. Their performance in controlling the real Hannes device was subsequently compared to a reference group of eight transradial limb difference individuals. Both MR-trained participants showed faster learning and better adaptation to the real prosthesis than the reference group. These preliminary findings suggest that the proposed MR framework, combined with an MR bimanual TAC test, may improve learning and user experience, ultimately contributing to lower prosthesis abandonment rates.

Nowadays, upper limb prosthesis acceptance remains low due to ineffective control techniques and the relative training methods. However, an engaging training method applied on early prosthetic fitting seems to have a positive impact on acceptance. To this aim, in this paper we present a Mixed Reality (MR) pre-fitting training system based on Microsoft HoloLens2, designed for users of the Hannes prosthetic hand. The system allows individuals with varying stump morphologies to control a holographic Hannes hand through a low-latency interface, replicating the physical architecture and motion of the real device in an immersive, portable environment. This pilot study presents the preliminary evaluation of the MR framework conducted with two limb difference participants (one naïve user and one experienced user in myoelectric prosthesis control) performing a novel bimanual Target Achievement Control (TAC) test. Their performance in controlling the real Hannes device was subsequently compared against a reference group of eight transradial limb difference individuals. Both MR-trained participants showed faster learning and better adaptation to the real prosthesis than the reference group. These preliminary findings suggest that the proposed MR framework, combined with a virtual bimanual TAC test, may improve learning and user experience, ultimately contributing to lower prosthesis abandonment rates.