Medical applications using tunable metamaterial systems and methods

An implantable medical device, comprising:

• a receiver to wirelessly receive electromagnetic energy from an external interface device while the medical device is at least partially implanted within a patient, the received electromagnetic energy providing at least one of wireless power and wireless control signals to cause the medical device to perform a function while at least partially implanted within the patient;
• an antenna system with a plurality of sub-wavelength antenna elements in communication with a plurality of selectively variable impedance elements;
• and
• a control system to control radiation patterning of the antenna system based on a scattering matrix (S-Matrix) of electromagnetic field amplitudes for each of a plurality of lumped ports, wherein the lumped ports include:
• a plurality of lumped antenna ports with impedance values corresponding to the impedance values of each of the plurality of selectively variable impedance elements;
• and
• at least one lumped external port corresponding to at least one target location within the patient.

A method, comprising:

• at least partially implanting a first medical device within a patient to selectively perform a function within the patient;
• and
• wirelessly interfacing an external interface device with the first medical device to cause the first medical device to perform the function within the patient, wherein the external interface device includes an antenna system with a plurality of sub-wavelength antenna elements in communication with a plurality of selectively variable impedance elements, and a control system to control radiation patterning of the antenna system based on a scattering matrix (S-Matrix) of electromagnetic field amplitudes for each of a plurality of lumped ports, wherein the lumped ports include a plurality of lumped antenna ports with impedance values corresponding to the impedance values of each of the plurality of selectively variable impedance elements;
• and at least one lumped external port corresponding to the first medical device at least partially implanted within the patient.