A semiconductor ball (10) comprises on a spherical substrate, one or more transducers/actuators (12) for sensing/stimulating body medium. The sensor/actuator (12) interfaces to processing circuitry (14) for communicating thereto. A power regulator (16) provides a relatively constant DC voltage to all onboard circuits, the power coupled from an external source via a coil (18) having coil ends (18a) and (18b). The processing circuitry (14) provides an output to a transmitter (20) that radiates a radio frequency signal to an external monitoring station (120).
