臺灣博碩士論文加值系統

功能性神經肌肉電刺激系統目前已多元化發展應用在復原已失去的神經系統功能。由於近來微電子技術、微機電技術、生物材料與生物相容性封裝技術的突破，使得微電刺激系統將趨向於微小化、可植入式的發展型式。然而在目前國內神經肌肉電刺激研究領域，仍侷限在表面電刺激的形式。為了能提供更好的電刺激選擇性及消除複雜的拉線連接方式，因此我們發展一套具無線傳輸功能之微型化植入式電刺激系統。這項技術的發展在恢復神經系統功能的輔具上將成為新的轉變。
在以超大型積體電路實現系統之前，我們目前先以離散電子元件設計實現一雛型植入式神經肌肉電刺激系統。整體植入式系統包含了外部傳輸電路與植入式微電刺激器。外部單元以無線遙測方式傳送指令資料及電源至植入單元，以高效率E類放大器配合電感耦合方式來實現無線透膚式傳輸技術。植入式微電刺激器透過射頻調變載波訊號由體外單元加以控制，而無線射頻接收轉換電路提供植入單元穩定電源與解調之訊號，再由微電刺激器產生可控制的定電流刺激波形，實現以電刺激神經而產生功能性動作與神經訊號的阻斷。
目前我們已經成功的設計、實現與測試完成了植入式神經肌肉電刺激器所有系統的功能;其中90%高效率自我振盪E類發射器的設計，做為射頻無線資料與電源的傳送。而植入單元微電刺激器系統，利用離散電子元件實現在三公分直徑圓形雙面印刷電路板上，整體功率消耗在30mW。發射線圈與接收線圈的距離允許在3公分以內，微電刺激器可穩定的工作，並在發射線圈的外圍內允許側向偏移。此雛型植入式微電刺激器可產生兩通道多樣式的電刺激規格。目前將使用在急性的動物實驗並提供未來積體電路微型設計之基礎。
關鍵字：植入式微電刺激器、無線傳輸、E類發射器。

The functional neuromuscular stimulation system has been developed and applied to restore the lost neural function in a variety of applications. Due to the advances in microelectronics, micromachining, biomaterials, and biocompatible package technology, the microstimulator system can be fabricated in a miniaturized and implantable type. However, the domestic researches in neuromuscular stimulation are still limited in the utilization of surface stimulation. In order to provide better stimulation selectivity as well as eliminate the long wire connecting electrodes and controller, therefore, we developed a miniaturized and wireless total implantable microstimulator system. This new technology will become a new alternative for the rehabilitation of neurological disorders.
Before fully fabricated with VLSI, current study is to design an implanted neuromuscular stimulation system by using the discrete electronic components. This entire implantable system includes external transmission circuit and implanted microstimulator. The external unit transmits the commands and data as well as the power necessary for the internal unit via wireless telemetry. This wireless transcutaneous transmission is achieved by high efficiency class-E amplifier and inductive coupling technique. The implanted microstimulator is externally controlled and powered by a modulated radio frequency signal. The receiver circuitry of the implant provides the stably regulated voltage and demodulates the data from radio frequency signal. The microstimulator has controllable constant current stimulation channels for nerve stimulation and blocking purpose.
We have successful designed, implemented, and tested all the functional blocks of implantable neuromuscular stimulation system. A high efficiency class E power transmitter with self-oscillating was designed for providing RF power and data to implant, whose efficiency can be up to 90%. In the implanted device, the microstimulator is built on the double-layer of printed circuit board in 3 cm diameter by using electronics discrete components. The overall power consumption of implanted device was measured around 30 mW. Thus, this implantable microstimulator system can operate precisely when the distance between the transmitter coil and receiver coil is within 3 cm. Within this distance, lateral displacement of receiver coil is allowed as long as it is inside the area of transmitting coil. This prototype implantable microstimulator can generate two channels of wide range stimulation specifications. This prototype currently can be used for acute animal experiment and for a basis of ASIC design in the future.
Keywords: Implantable microstimulator, wireless transmission, class E transmitter.

Chapter 1 Introduction ………………………………………………1
1.1 Background…………………………………………………1
1.2 Introduction to implantable microstimulator system…2
1.3 Motivation and the aims of this study…………………8
Chapter 2 Material and Methods.……………………………………9
2.1 The overall structure of implantable microstimulator system…………9
2.2 Design of wireless power and data transmission…………10
2.2.1 Design of class E transmitter……………………………11
2.2.2 Wireless data transmission………………………………15
2.3 Design of implanted device with multichannel microstimulator........................................18
2.3.1 Power recovery circuitry…………………………………19
2.3.2 ASK demodulation circuit………………………………21
2.3.3 Consideration of stimulus waveform for implanted nerve stimulation………22
2.3.4 Implanted microstimulator design………………………23
Chapter 3 Results……………………………………………………25
3.1 The overall implemented system……………………………25
3.2 External control unit………………………………………26
3.3 Result in class E transmitter……………………………28
3.4 Implanted microstimulator system…………………………33
3.4.1 ASK demodulator…………………………………34
3.4.2 Voltage regulator………………………………34
3.4.3 Overall efficiency…………………………………………36
3.4.4 Microstimulator………………………………………………37
Chapter 4 Discussion and Conclusion……………………………40
4.1 Discussion………………………………………………………40
4.2 Conclusion and future development………………………41
References……………………………………………………………42

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