Disclosed is an implantable medical device and methods of using the medical device. The medical device may include a guided surface wave receive structure configured to receive a guided surface wave transmitted by a guided surface waveguide probe. The guided surface wave receive structure in the medical device generates an alternating current signal when the guided surface wave is received. The medical device includes a power circuit that is coupled to the guided surface wave receive structure. The power circuit includes a power storage circuit to store the power signal. The medical device includes a medical circuit that comprises a stimulus circuit, a monitoring circuit, and potentially other components. The stimulus circuit provides a stimulus to a human body. The monitoring circuit measures a characteristic of the human body.