The NESS Handmaster orthosis: Restoration of hand function in C5 and stroke patients by means of electrical stimulation

The NESS Handmaster is a new non-invasive hybrid (orthosis combined with functional neuromuscular stimulation) neuroprosthesis which has been developed for therapy and restoration of hand function to the paralyzed upper limb in C5 tetraplegia, CVA and brain injuries. The system comprises a spiral wrist-extension splint housing the electrode array which is connected to the control unit by a thin flexible cable. It has been designed for independent use for both stroke and tetraplegic patients. Two exercise modes and three functional modes (grasp, key-grip and hand open) can be generated with the Handmaster. During the last year, several rehabilitation centres in Europe were provided with trial versions of the Handmaster in order to transfer the device to the market. Suitable tetraplegic candidates are those with C5 lesions with a loss of wrist extension activity. We concluded from literature and our own findings that these patients can benefit from the Handmaster with respect to performance of tasks in daily living. Examples of tasks which can be performed by means of the Handmaster are replacing a tape in a videorecorder, use of an electric razor for shaving, and drinking coffee. Reduction of spasticity seems to be the main therapeutic outcome in stroke patients. However, this reduction might be achieved by the stimulation as well as the orthosis. Further analysis of both components is required in order to determine treatment interaction.