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Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review

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      Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver.

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            Author and article information

            Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15213, USA; knb12@
            Author notes
            [* ]Correspondence: esejdic@ ; Tel.: +1-412-624-0508
            Role: Academic Editor
            Sensors (Basel)
            Sensors (Basel)
            Sensors (Basel, Switzerland)
            18 March 2016
            March 2016
            : 16
            : 3
            26999154 4813968 10.3390/s16030393 sensors-16-00393
            © 2016 by the authors; licensee MDPI, Basel, Switzerland.

            This article is an open access article distributed under the terms and conditions of the Creative Commons by Attribution (CC-BY) license (



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