Adaptable Poly-Articulated Bionic Hands EnhanceBoth Performance and User's Perception in Bilateral Amputation: A Case Study.

This article evaluates and compares the performance and perception of prosthetic devices based on different design principles, a traditional rigid gripper and an adaptable poly-articulated hand, in a pre- and post-training protocol with an individual with bilateral amputation. As a representative of the first class, we use commercial hands (Ottobock's MyoHand VariPlus Speed), which is a widely adopted model by prosthesis users worldwide. We compare these with two SoftHand Pro hands, which are experimental prototypes exhibiting 19 articulations actuated by one single motor, and are inspired by human hand motor control models. Results show that the individual with bilateral amputation, who was a non-expert myoelectric user, achieved better performance with adaptive poly-articulated hands. Furthermore, the acceptation, satisfaction and perceived functionality of the user were considerably higher for the SoftHand Pro. An observational analysis of the patient's behaviour by experienced therapists suggests that adaptable poly-articulated hands reduced compensatory movements and cognitive load. Using soft technologies may be especially advantageous for individuals with bilateral amputation, who present a very limited residual mobility and can largely benefit from the active use of their artificial arms in everyday life.