A Novel Mat-Based System for Position-Varying Wireless Power Transfer to Biomedical Implants

Abstract

Wireless power transfer via magnetically resonant coupling is a new technology to deliver power over a relatively long distance. Here, we present a mat-based design to wirelessly power moving targets based on this technology. Our design is specifically applied to transcutaneously power medical implants within free-moving laboratory animals. Our system comprises a driver coil array, a hexagonally packed transmitter mat, a receiver coil, and a load coil, and generates a nearly flat magnetic distribution over a defined area to produce an approximately constant power output independent of the location of the receiver coil. This paper also describes a novel power receiver coil design of the same shape as the exterior of the implant, allowing for maximum magnetic coupling, eliminating the space restrictions due to the coil within the implant, and matching the resonant frequencies of the implant and the transmitter coil. Our new transmitter and receiver designs significantly reduce the size of a biomedical implant and may provide a lifetime power supply to implanted circuits without the need for an internal battery. Our designs are also useful in various other applications involving moving targets, such as part of a robot or a vehicle.Index Terms-Biomedical implant, driver-coil array, magnetically resonant coupling, mat-based design, wireless power transfer (WPT).

A Critical Review of Wireless Power Transfer via Strongly Coupled Magnetic Resonances

“…Chang et al [78] pointed out that batteries can be replaced by this novel technology, the energy for implantable devices can be supplied wirelessly. Xu et al [79] presented a new wireless power mat system which can supply the energy for medical implants in the body of free-moving laboratory animals.…”

“…Transient analysis based on CT is sometimes more accurate than that based on CMT [18], thus CT is widely adopted. Various hot research spots, including system architectures [14][15][16][17], frequency splitting [11,24,26,28,48,49], impedance matching methods [20,26,27,[50][51][52][53][54][55][56][57][58][59][60], optimization designs [25,42,[61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77] and practical applications [37,[78][79][80][81]…”

Design algorithm of a uniform magnetic field transmitter intended for the wireless charging of electric vehicles

“…The first structure is a coil array made of many smaller coils [9]- [11], which are arranged tightly in some geometry form. If this design is applied to charge electrical vehicles, the selfinductance of the transmitter coil would be so large that the voltage of the coil would be extremely high.…”

Optimal design and analysis of wireless power transfer system with converter circuit

“…After entering the end of the twentieth century, to realize the wireless charging for implanted medical devices provides a safe and reliable method to solve the supply problem. Thus WPT technology receives more and more attentions from the researchers in biomedical engineering [4][5][6][7].…”