A surface acoustic wave device in which miniaturization and a flat design implemented, is resistant to a deformation responsive to a pressure of a molten resin in the formation of a mold resin layer, and is less susceptible to a characteristic degradation. A first coupling element is carried by the appliance and a second coupling element is carried by the detachable power supply device. A monitoring device data module is configured to receive measurement data from at least one of the patient monitoring devices.