Backward Data Transfer From Deeply Implanted Device Employing Ultrasonic Load Amplitude-Phase Shift Keying.

Ultrasonic transcutaneous energy transfer (UTET) is used to wirelessly energize low-power miniature implanted devices. Whenever backward data transfer from the implant is of interest, load modulation may be utilized. With load modulation, data is sent backward by imposing ultrasonic reflections from the implant-tissue contact surface.

Simultaneous backward data transmission and power harvesting in an ultrasonic transcutaneous energy transfer link employing acoustically dependent electric impedance modulation.

The advancement and miniaturization of body implanted medical devices pose several challenges to Ultrasonic Transcutaneous Energy Transfer (UTET), such as the need to reduce the size of the piezoelectric resonator, and the need to maximize the UTET link power-transfer efficiency. Accordingly, the same piezoelectric resonator that is used for energy harvesting at the body implant, may also be used for ultrasonic backward data transfer, for instance, through impedance modulation. This paper presents physical considerations and design guidelines of the body implanted transducer of a UTET link with impedance modulation for a backward data transfer.

Noninvasive control of the power transferred to an implanted device by an ultrasonic transcutaneous energy transfer link.

Ultrasonic transcutaneous energy transfer is an effective method for powering implanted devices noninvasively. Nevertheless, the amount of power harvested by the implanted receiver is sensitive to the distance and orientation of the external transmitting transducer attached to the skin with respect to the implanted receiving transducer. This paper describes an ultrasonic power transfer link whose harvested power is controlled by an inductive link.

Ultrasonic transcutaneous energy transfer using a continuous wave 650 kHz Gaussian shaded transmitter.

This paper proposes ultrasonic transcutaneous energy transfer (UTET) based on a kerfless transmitter with Gaussian radial distribution of its radiating surface velocity. UTET presents an attractive alternative to electromagnetic TET, where a low power transfer density of less than 94 mW/cm(2) is sufficient. The UTET is operated with a continuous wave at 650 kHz and is intended to power devices implanted up to 50mm deep.

Ultrasonic transcutaneous energy transfer for powering implanted devices.

This paper investigates ultrasonic transcutaneous energy transfer (UTET) as a method for energizing implanted devices at power level up to a few 100 mW. We propose a continuous wave 673 kHz single frequency operation to power devices implanted up to 40 mm deep subcutaneously. The proposed UTET demonstrated an overall peak power transfer efficiency of 27% at 70 mW output power (rectified DC power at the load).