Main description:

Omnidirectional Inductive Powering for Biomedical Implants investigates the feasibility of inductive powering for capsule endoscopy and freely moving systems in general. The main challenge is the random position and orientation of the power receiving system with respect to the emitting magnetic field. Where classic inductive powering assumes a predictable or fixed alignment of the respective coils, the remote system is now free to adopt just any orientation while still maintaining full power capabilities. Before elaborating on different approaches towards omnidirectional powering, the design and optimisation of a general inductive power link is discussed in all its aspects. Special attention is paid to the interaction of the inductive power link with the patient's body. Putting theory into practice, the implementation of an inductive power link for a capsule endoscope is included in a separate chapter.

Contents:

Abstract. List of Abbreviations and Symbols. 1 Introduction. 1.1 Wireless Power Transmission. 1.2 Types of Wireless Power Transmission. 1.3 A Biomedical Perspective. 1.4 Inductive Links. 1.5 Conclusions. 1.6 What to Expect. 2 Magnetic Induction. 2.1 Maxwell's Equations. 2.2 Conductive Wire. 2.3 Inductance. 2.4 Inductor Models. 2.5 Finite Element Modelling. 2.6 Conclusions. 3 Inductive Link Design. 3.1 Link Equations. 3.2 Loose-coupling Approximation. 3.3 Tertiary Circuits. 3.4 Link Optimisation. 3.5 Misconceptions about k and Q. 3.6 Conclusions. 4 Power Converters and Voltage Regulators. 4.1 Rectifiers. 4.2 Inverters. 4.3 Voltage Regulators. 4.4 Conclusions. 5 Omnidirectional Coupling. 5.1 Problem Definition. 5.2 Multiple Primary Coils. 5.3 Multiple Secondary Coils. 5.4 Conclusions. 6 Biological Tissue Interaction. 6.1 Electromagnetic Fields in Biological Tissue. 6.2 Health Effects of Electromagnetic Fields. 6.3 Exposure Limits and Regulations. 6.4 Examples from Biomedical Engineering Practice. 6.5 Conclusions. 7 An Inductive Power Link for a Capsule Endoscope. 7.1 Wireless Endoscopy. 7.2 Design: Choices and Motivation. 7.3 Fabrication. 7.4 Measurement. 7.5 Biological Tissue Interaction. 7.6 Conclusions. 8 A Class E Driver for Deformable Coils. 8.1 Class E ZVS Inverter with Transductor. 8.2 Control Loop. 8.3 Measurement Results. 8.4 Conclusions. 9 Conclusions. 9.1 Comprehensive Summary. 9.2 Main Contributions and Achievements. 9.3 Further Research. Appendix: Coil Measurements. A.1 Single Coil Characterisation. A.2 Coupling Characterisation. References. Index.