在微創手術的過程中，醫師無法直接利用觸診的方式對病變組織進行辨識判斷。本研究以感測致動(sensing cum actuating, SCA)方法為基礎，發展一套能配合微創手術用的軟組織剛性量測儀。本研究利用壓電材料的機電轉換特性，同時作為系統的致動器和感測器，不需要額外增加傳感器量測軟組織的響應，能大幅降低系統的尺寸與複雜性。因為採用微小探頭，系統傳感矩陣的校正是以有限元素分析取代過往的實驗方法完成。為了驗證探頭分辨物體機械性質的正確性，本研究以兩種具黏彈性的矽膠和豬肝(正常、冷凍)作為實驗的樣本，量測系統輸入端電路阻抗的變化，再配合系統的傳感矩陣，估測出軟組織的機械阻抗。結果顯示，在系統共振頻率的附近(2.0k~2.5kHz)，無論是電路阻抗或機械阻抗，都可明顯區別各樣本性質的差異性，而且與樣本的剛性排序有一致的結果。以臨床應用來說，本研究所設計的軟組剛性量測儀能確實、有效地分辨軟組織的機械性質。最後，估測的機械阻抗可利用Kelvin模型作參數擬合，以量化軟組織的機械性質。

Surgeon’s perception of palpation is limited during the minimally invasive surgery (MIS). Based on sensing cum actuating method (SCA), the goal of this study is to develop a stiffness measuring device for MIS. In this mechatronic system, a PZT acts as actuator and sensor simultaneously and no additional transducer is needed to measure the response of soft tissues. Thus it greatly reduces the size and the complexity of system design. Due to miniaturization of the device, calibration of system transduction matrix is accomplished by using finite element analyses. To verify the performance of the device, two kinds of viscoelastic materials: silicon gel and porcine liver (normal, frozen) are utilized as the specimens in this research. By measuring the input electrical impedance, mechanical impedance of the specimen is calculated by using the calibrated system transduction matrix. According to the results, from either the electrical impedance or the mechanical impedance, the difference of mechanical property among the specimens can be easily distinguished around the resonance frequency (2.0k~2.5kHz). Also, the results showed very good agreement with stiffness of the specimens. In clinical applications, the mechanical property of biological soft tissue can be effectively distinguished by using the designed measuring device. Finally, Kelvin model is also adopted to fit the experiment data and the model parameters can be estimated for quantifying the property of living soft tissues.

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