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The circuits in wireless power transfer can be classified to power converters and power management circuits. We present the power management in this chapter. The power management is actually everywhere in the wireless power transfer, especially for those relatively complex systems. In this chapter, we firstly build a circuit model of the power management in the wireless power transfer for biomedical applications. Secondly, we present several detailed designs, including the automatic tuning adjustment, the power adjustment, the wireless power watchdog, the wireless power switch, and the recharging management circuit. These designs are to improve the transfer efficiency and the system reliability, or fulfill other purposes. By using them, the wireless power transfer becomes smarter.

To conclude, we have given an introduction to the wireless power transfer for biomedical applications in Chap. 1. By developing the wireless power transfer, researchers hope to provide biomedical devices with more power, longer operating time, smaller system size, and safer insurance. Chapter 2 has presented the systematic design for typical transfer systems. The working principles, classifications, systematic design considerations, and safety concerns were introduced. From Chaps. 3, 4, 5, we have illustrated many designs regarding power antennas, power converters, and power management. By using them, two design cases have been proposed in Chap. 6 for the batteryless capsule endoscopy. In the final chapter, we are going to review the work we have introduced. Moreover, we would look into future and summarize major challenges in the future.

The wireless power antenna plays an important role in the wireless power transfer. To reduce the system size, realize the full directionality, improve the coupling efficiency and other parameters, various kinds of power antenna techniques have been proposed in recent years. Accordingly, these techniques constitute many wireless power transfer structures. In this chapter, we firstly give an overview to the power antenna techniques in the wireless power transfer, introduce their classification and detailed catalogs, and discuss their design considerations. Second, four kinds of transfer structures are presented with details. They are the LC-pair, the Multiple-resonators, the Quad-loops, and the Helix-derivatives. Both basic design methods and advanced optimizations are to be proposed or explained. Although the transfer structures share the same physical principles, they have entirely different performances and application conditions.

A wireless power transfer is composed of power antennas and power circuits. Besides the antennas introduced in the Chap. 3, many circuit techniques have already been developed in past years. They can be classified into the power converters and the power management techniques. We introduce the power converters in this chapter. First, we build a circuit model for the power converters. Second, their design considerations are discussed for biomedical applications. These considerations include higher system efficiency, better system adaptability, smaller circuit size, stronger system reliability, and so on. Third, the techniques of the converters are elaborated one by one. They are the AC–DC converters, the DC–DC converters, and the DC–AC converters. Since the design of the AC–DC converter is so important for the wireless power receiver and the technology is developing fast, we mainly talk about the AC–DC converter in this chapter.

Wireless endoscopic Micro-Ball system makes it possible to generate the map of gastrointestinal (GI) tract wall. This paper proposes a new method for the generation of small intestine map based on the attitude sensing system embedded in the endoscopic Micro-Ball. In this method, the captured images can be inversely projected on the interior wall of small intestine and then 2D representation of the inversely projected images can be created. The method reduces the complexity of 2D representation of small intestine map, because it removes the perspective distortion of the captured images. Moreover, the attitude information related to the images determines the location of the generated images in the small intestine map. The location information can reduce the amount of calculation when used in image registration of the endoscopic Micro-Ball images. Experimental results show the method is feasible and high efficient.

Nowadays the interpretation of the images acquired by wireless endoscopy system is a tedious job for doctors. A viable solution is to construct a map, which is a 2D representation of gastrointestinal (GI) tract, based on image registration to reduce the redundancy of images and improve the understandability of them. Nevertheless, the limited field of view makes it difficult for traditional wireless capsule endoscopy system to capture sufficient image information for a complete GI map. The work reported in this paper addresses the problem of the 2D representation of GI tract based on a new wireless Micro-Ball endoscopy system with multiple image sensors. This paper analyses the characteristics of images captured by Micro-Ball endoscopy system and proposes a determination method for registration of wireless endoscopic images based on phase correlation method (PCM). The performance of PCM and the proposed determination method is verified with experiments.

While wireless endoscopic capsule examining human's large gastrointestinal (GI) cavity, such as stomach and large intestine, it is possible that many interested spots are omitted by the one or two cameras due to its limited field of view. This paper proposes a new globularity capsule endoscopy system with multi-camera. Through analyzing the multi-camera system's optical characteristic and power consumption of the endoscopic capsule system, this paper proposes the spatial physical structure and the electronic architecture of the globularity capsule without blind area. Its diameter can be less than 15mm. The capsule can work in human's GI tract for 8 hours when the image frame rate is 4fps.

Because of changing temperature, silicon's wearing out, and the other unpredictable factors, besides testing on chips when leaving factory, in some applications, such like life-protected and aviation system, microchips need real-time and in-operation test even if they have been used in system. This paper focuses on a new in-operation self-testing mechanism. This mechanism is used to detect the silicon defects of cores of SoC chips in working state. It makes embedded cores to automatically check their failures by themselves based on IEEE std I500TM and Core Test Language. According to Experiments, as a compromise, this In-operation Self-Test mechanism slows down the computation performance of SoC chips. Using this mechanism ensures finding exception in time and in turn adopting spare scheme in time, as well as it outperforms previous approaches in reducing cost of importing failure tolerance mechanisms into SoC chips.

Proposed is a two-stage image compression method for wireless capsule endoscopy images to provide high compression rate and high image quality. The first stage, implemented inside the wireless capsule, contains a very low complexity integer transform followed by an optimised quantisation and Huffman encoding. The second stage is a simple post-processing for high subjective visual quality of the reconstructed image, which is applied outside the capsule. The compression method can provide not only high compression rate (86%) and high image quality (39.2 dB), but also low computation complexity.