The invention relates to a system having high-temperature fuel cells, for example SOFCs. The apparatus can also include the data storage component andor the host device. During use, the prosthetic device is attached to tissue of the gastro-esophageal junction region of the patient, with the device positioned such that food ingested by the patient passes from the esophagus through the proximal opening into the interior of the prosthetic device, and eventually exits the prosthetic device via the distal opening.