Wireless Power and Data Transmission for Implanted Devices via Inductive Links: A Systematic Review

Wireless power and data communication systems in implantable medical devices (IMDs) are developed to control and report acquired biological data from an implanted device to an external stage in several medical applications. Ultrasonic, capacitive, optical, radio frequency (RF), and inductive links are employed as a wireless power and data transmission technique. Inductive power transfer (IPT) is one of the most commonly used techniques due to its robustness, simplicity, safety, and capability of simultaneous and bidirectional data and power transmission. This paper presents a systematic review and survey of the latest inductive power and data transmission methods for IMDs. The fundamental principles of remote powering through inductive links, the critical parameters of design, and power transfer efficiency calculations are presented. Single and multiple inductive links, the advantages and drawbacks, optimization methods, and comparison by their performances are explored. In addition, modulation schemes, along with improvement techniques reported in the literature, the strengths and limitations, and the measured or the simulated data rate of each are also reviewed. A benchmarking table with summarized design features of systems, essential parameters for wireless powering and data communication, and categorized Figure-of-Merits (FoMs) to compare performances are also provided.