Abstract

After the amputation of a limb, up to 90% of the patients report a feeling of the missing body part still being present in their perception. This effect is known as phantom limb sensation and ranges from the simple feeling of presence to a specific position, shape or phantom pain. To alleviate this pain, patients engage in mirror therapy during which a mirror is placed in front of the patient’s midsection, and the patient, while looking into this mirror, imagines that the amputated limb is in fact the healthy limb reflected in the mirror. However, this method is not without limitations. To address these limitations of conventional Mirror Therapy therapy and take advantage of the inherent potential of commercial technology, we developed an innovative assistive therapy tool based on mixed reality (MR) on the Microsoft Hololens 2. In this way, the patient’s residual limb would be augmented by a superimposed virtual arm that is completely independent from the movements of their sound limb and can interact with the environment. Patients should move around freely and perform bi-manual tasks. To achieve this, we developed an MR appliaction that includes controllers for moving the virtual hand via myoelectric sensors (EMG) and inertial units and created and 4 different interaction scenes. We anticipate that this type of immersive MR rehabilitation will have a positive impact on outcomes related to pain scores, hand/arm functionality, range of motion, and motivation to perform therapy, even when no therapist is present.