使用超音波陣列系統實現植入式裝置的偵測及能量傳輸

中文摘要隨著微電子技術的成長，微小的醫療儀器以植入人體的方式作針對性的診斷輔助與治療，可以增加診斷及治療的準確性，且能減緩病人的不適性。常見的植入式儀式，如膀胱節律器、神經刺激器等裝置以電磁波作為無線傳輸將訊號以及能量從外部傳到儀器內。由於需要能量的供應，一般植入式需要較大型的電池供應能量，因此無法大幅度的減少裝置的面積。無線充電成為解決上述問題的方法之一。除了以電磁波作無線傳輸能量外，近年的研究顯示以超音波作為傳輸能量的方式、在面積日漸減小的植入式裝置下能接收到更多能量。但是要達到使用超音波作無線傳輸訊號及能量的目的，需要對裝置作編碼和定位，為了達到上述目前，本論文討論如何利用超音波陣列系統作的定位以及編碼、並在FDA規範的Isppa與Ispta限制內，使用超音波感測器可收到的能量範圍下，設計一功率為2.3 mW的低耗電植入式神經刺激器IC，以符合超音波傳輸特性的解調方式，設計編碼及能量傳輸方式。此IC能達到植入式裝置進行充電、以及資料傳輸等操作。為了方便達到以上目的，陣列系統的定位、達到將能量聚焦在植入式裝置上，我們把裝置設計成以階梯狀的微結構，利用B-mode影像達到粗略超音波定位的目的並結合時頻分析，來準確定位到微結構位置。最後整合超音波陣列系統，因陣列系統同時具備聚焦和影像的功能，分析陣列系統影像的原始通道資料，得到較準確定位的能力。而本研究中將把裝置放置在3-7 cm的深度，控制超音波聚焦位置，使超音波能量聚焦在植入式裝置上; 並由感測器接收能量，最後由陣列系統編碼，達成無線充電和信號傳輸的功能。而IC將會對編碼後的訊號作解調，得到所需神經刺激功能。結果顯示利用本研究所提出的方法能有效的對裝置作定位、充電以及資料傳輸等三大功能。關鍵字：超音波無線能量傳輸、超音波陣列系統、植入式裝置、定位、階梯狀微結構

關鍵字

超音波無線能量傳輸；超音波陣列系統；植入式裝置；定位；階梯狀微結構

並列摘要

Abstract Traditionally, the power for an implantable device is provided by a battery. Therefore, there are certain limitations including changing the battery and the size of the battery. Wireless power transfer is one of the solutions to alleviating such problems. Recently, we have demonstrated that wireless power transfer can be achieved by ultrasound and the implantable device can be detected by ultrasound using a housing with specific microstructures. In this study, we hypothesize that these tasks can all be performed by a clinical ultrasound array system. The custom design IC in the implantable device is 2 mm×2.2 mm and we are able to transfer power of 2.3 mW which is more than enough for neural stimulation. There is also a pyramid microstructure on the implantable device, which reflects ultrasound to generate signals with specific spectral characteristics. Applying time-frequency analysis to analyze the signal, frequency deceasing occurs and location of the device can be detected. Thus, we have demonstrated that neural stimulation using the proposed setup can be performed using a clinical ultrasound array system. Keywords: implantable system, wireless power transferring, microstructure, ultrasound array system, localization

並列關鍵字

implantable system ； wireless power transferring ； microstructure ； ultrasound array system ； localization

參考文獻

[1] A. Denisov, and E. Yeatman, "Ultrasonic vs. Inductive Power Delivery for Miniature Biomedical Implants," IEEE 2010 International Conference on Body Sensor Networks pp. 84-89, June 2010.

[2] Y.T. Hu, X. Zhang, Y. Jiashi, and J. Qing, "Transmitting electric energy through a metal wall by acoustic waves using piezoelectric transducers," IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, vol. 50 pp. 773-781, July 2003.

[3] S. Sherrit, M. Badescu, X. Bao, Y. Bar-Cohen and Z. Chang, "Efficient electromechanical network model for wireless acoustic-electric feed-throughs," SPIE Smart Structures Conference, pp. 362-372, May 2005.

[4] J. Charthad, M.J. Weber, C.C. Ting, and M. Saadat, , "A mm-sized implantable device with ultrasonic energy transfer and RF data uplink for high-power applications," 2014 IEEE Proceedings of the Custom Integrated Circuits Conference pp. 1-4, June 2014.

[5] B.C. Towe, P.J. Larson, and D.W. Gulick, "A microwave powered injectable neural stimulator," 2012 Annual International Conference of the Engineering in Medicine and Biology Society pp. 5006-5009, Aug 2012.

國際替代計量

使用超音波陣列系統實現植入式裝置的偵測及能量傳輸

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