一般人體器官病變時會伴隨組織剛性的改變，因此肝臟外科手術主要是先以觸診方式確認患部然後再進行切除。本研究應用感測致動理論( Sensing Cum Actuating theory, SCA)發展壓電式軟組織剛性量測系統來量化組織剛性，提供外科醫師於手術時能即時獲得較為準確且客觀的組織病變位置。感測致動理論的原理是驅動壓電傳感器刺激軟組織樣本時，樣本之機械性質會以電性變化的方式反映至傳感器，藉由量測驅動端之電壓和電流即可求得軟組織剛性，不需額外的力量和速度感測元件。本研究先進行傳感器上電壓, 電流, 力量和速度等四個物理量之間的動態模型推導，之後再進行量測系統校正實驗，如此可求得電能與機械能之間物理量轉換關係。為了驗証量測系統之準確性，研究中以多種矽膠與豬肝作為實驗樣本，分別利用本量測系統與材料試驗機進行剛性量測並比較兩者之差異。研究得知，在致動頻率1k~2kHz的情況下量測系統可區別出不同剛性之實驗樣本，且與材料試驗機量測結果呈正相關，唯量化結果無明顯趨勢，推測該頻率範圍下可能有功率損耗，造成壓電傳感器於機械能與電能轉換時的失真，所以不易量化。雖然本量測系統尚無法利用感測致動理論量化組織剛性，但是可從電路阻抗變化中觀察出組織剛性之變化，因此對於臨床應用而言仍有一定的實用價值。

There are some changes in stiffness of the human tissues caused by the pathological changes. In the surgery, the surgeons use only palpation for the diagnosis of the condition of patient’s internal organs. To quantify the stiffness of soft tissues, sensing cum actuating theory (SCA) is adopted in this thesis for developing a PZT-based soft tissues stiffness measurement system.
The principle of the SCA theory is when a soft tissue was excited by a piezo-transducer and the reaction force from the mechanical property of the soft tissues changes the electrical impedance in the input port of the piezo-transducer. Then the stiffness of the soft tissue can be deduced by measuring the voltage and current in the input port of the piezo-transducer without using force and velocity sensors. In this thesis, the lumped-mass transfer functions between the voltage, current, force and velocity of the piezo-transducer were derived first. Then a calibration experiment was performed to estimate the four transfer functions. In this study the silicones and porcine liver were chosen for testing the PZT-based soft tissue stiffness measurement system. Results of the PZT-based measurement system were compared with results of standard material testing system (MTS).
From the result at 1k~2kHz, it was confirmed that by using the PZT-based measurement system the experiment objects with different stiffness can be differentiated. And the results from PZT-based measurement system and MTS are positively correlated. But at certainty frequencies there was no trend in the quantification results of the PZT-based measurement system. It could be caused by the power loss between the electrical and mechanical energy changes of the transducer. In this study the stiffness of soft tissues at certain frequencies can not be quantified correctly by using the PZT-based measurement system, but the differentiation of stiffness of soft tissues still can be observed by the electrical impedance at the transducer input port. It may be concluded that the SCA measurement system can be used in future clinical application.

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