Upper Limb Amputees

The purpose of this study is to characterize proprioceptive sensations in the missing limb of upper limb amputees using nerve stimulation, and to develop advanced controllers for moving a prosthesis. Proprioceptive sensations are the sensations that tell individuals where their hand is in space, and if it is moving. The research team uses Functional Electrical Stimulation (FES), which involves applying small electric currents to the nerves. These signals are then transferred to the brain just like the information about the individual's intact hand used to be transferred to their brain. This study will test different placements for stimulation and determine which one(s) provide the individual with proprioceptive sensations. The investigators want to know what the participants feel and if the investigators can use proprioceptive sensation to give the participants information about limb movement and position.

Upper limb amputation still causes severe disability today; prostheses currently on the market are able to restore partially to the amputee the lost functionality. In addition to the motor capacity of the limb, prosthetic systems should also aim to restore to the sensory information from the surrounding environment during contact with objects. Therefore, it is important to develop bidirectional prostheses. It is thus apparent that the development of new techniques for decoding the efferent channel, such as high-density surface electromyography, and for encoding of the afferent channel afferent, to return multimodal somatosensory sensations of mechanoception, nociception, and thermoception using TENS, isimportant to improve the patient's use of the prosthesis.