Ultrasound energy harvesting system for deep implanted-medical-devices (IMDs)

摘要

It is desirable in active medical implants to derive energy from external sources to charge a rechargeable battery. In this paper we have developed a novel system to transfer energy via ultrasound to a deep implanted medical device. Hence, an external base station is designed to transmitt energy and a 64-channel high-voltage driver is proposed for a spherical transducer array. Moreover, a shunt-C class-E power amplifier (PA) is employed as core element for the driver, showing a drain efficiency (DE) of 71% and a power added efficiency (PAE) of 57% including gate-driver switching loss. In addition, a cascaded of two low-drop-out (LDO) regulators is used within the implanted device to reduce rectifier ripple and to set the charge voltage for the micro-energy cell to 4.1 V. The LDOs are implemented in a CMOS 0.18 µm high-voltage (HV) technology and measurement along with simulated results are reported.