Practical Inductive Link Design for Biomedical Wireless Power Transfer: A Tutorial

Abstract

Wireless power transfer systems, particularly those based on inductive coupling, provide an increasingly attractive method to safely deliver power to biomedical implants. Although there exists a large body of literature describing the design of inductive links, it generally focuses on single aspects of the design process. There is a variety of approaches, some analytic, some numerical, each with benefits and drawbacks. As a result, undertaking a link design can be a difficult task, particularly for a newcomer to the subject. This tutorial paper reviews and collects the methods and equations that are required to design an inductive link for biomedical wireless power transfer, with a focus on practicality. It introduces and explains the published methods and principles relevant to all aspects of inductive link design, such that no specific prior knowledge of inductive link design is required. These methods are also combined into a software package (the Coupled Coil Configurator), to further simplify the design process. This software is demonstrated with a design example, to serve as a practical illustration.

2d Disturbance Map of Low-Power Front-End Circuits in Low Frequency Band

“…To determine the mutual inductance, the method presented by Soma et al [14] and used by [2,15,16] in the analysis of the efficiency of inductive energy transfer was applied. The works of [17,18] are its extension, introducing the possibility of a more precise analysis of multi-winding coils based on replacing the integral from Equation (6) with its development into the Taylor series.…”

“…They are the basis of immobilizer systems [1] in the automotive industry, enabling two-way communication with the proximity key. In the case of basic configuration, such an interface consists of a transmitting coil and appropriately linked receiving coil, which is usually loaded with the active structure of Analog Front End (AFE) input circuit [2,3]. Due to the variable orientation of coils and the non-linear nature of AFE circuits, optimal adaptation to the receiving coil (e.g., in the sense of the RF emission level) is usually possible only in a limited scope.…”

Evaluation of Specific Absorption Rate in Three-Layered Tissue Model at 13.56 MHz and 40.68 MHz for Inductively Powered Biomedical Implants

“…Implantable devices with wireless connectivity has led to many advances in the field of biomedical applications, as they allow long term powering of devices within the human body [1][2][3][4][5][6]. The principal power required by the medical implants such as cochlear implants, retinal prostheses, pacemakers, and neural recordings are different [7][8][9] and therefore powering these devices without damaging the tissues remain an arduous challenge. The conventional techniques used physical wirings and batteries to provide power to the implantable medical devices (IMDs).…”

Correction to “Practical Inductive Link Design for Biomedical Wireless Power Transfer: A Tutorial” [Oct 18 1112-1130]

“…T HE original paper entitled 'Practical Inductive Link Design for Biomedical Wireless Power Transfer: A Tutorial' [1], aimed to provide an accessible review and guide, describing the necessary steps for designing effective biomedical inductive links, without the need for FEM software.…”

“…The errors largely relate to the equations presented throughout, and are listed below: Firstly, Equation 2in [1], defining an approximation for Nagaoka's coefficient, contains erroneous squares and is missing a term in the fraction of the large denominator. The correct form is presented below:…”