A Comprehensive Review on Rectifiers, Linear Regulators, and Switched-Mode Power Processing Techniques for Biomedical Sensors and Implants Utilizing in-Body Energy Harvesting and External Power Delivery

This article reviews the state-of-the-art power conditioning techniques to process harvested energy from the human body and any external environmental sources surrounding the human body for powering biomedical implants and sensors. The fundamental focus of this article is to highlight the necessity of power conditioning circuits to energize implanted biomedical circuits. In addition, the underlying challenges in power conversion modules used in these low-power circuits have been discussed in detail. Power conditioning techniques for biomedical implants heavily rely on the type of sources and implants, thereby we aim to provide an elaborate discussion on the operating principle of individual technique through this review. Besides, we have also explored the suitability of each individual power processing technique inside the human body with great details. Finally, a comprehensive discussion on the limitations of existing power conditioning techniques has been presented, and the scopes to improve or mitigate those limitations have been discussed as well. The goal of this work is to present a complete guideline for future researchers to downselect a compatible power conditioning technique for a specific biomedical application.