SPR's SMARTPATCH® Peripheral Nerve Stimulation (PNS) System is intended to be used for up to 30 days for pain relief. It has received CE mark approval for treatment of chronic shoulder pain. In the United States, this short-term, PNS system is being evaluated in multiple studies for chronic shoulder pain, post-amputation pain, and post-surgical pain following knee replacement. The system consists of an implanted percutaneous lead, a skin-mounted external stimulator, and Smartpatch pads and small adhesive patches. It has an integrated battery that serves as a power source for the system. The Smartpatch pad is replaced regularly based on treatment parameters, allowing the clinician to prescribe the total dosage based upon the number of Smartpatch pads provided to the patient.