Electrical impedance Analysis for Intra-operative Monitoring and Tissue Identification

生物阻抗量測是一種便宜、簡單且便於使用的生物組織分析方法，本文專注於以自製之阻抗量測平台測量不同生物材料的阻抗。 在此研究中我們使用此平台模擬經尿道攝護腺切除手術之過程，以監測尿道直徑與出血量的初步離體模型。所測量之阻抗與量筒之直徑的相關係數很高，而使用生理食鹽水模擬的出血量也能由平台偵測。 此外本研究也使用此系統進行多頻率測量以分辨雞眼於疣之特性。由於指甲的角質厚度與雞眼範圍相當，最初我們以指甲角質作為平台的可用性測試，但是個人指甲本身雖然有相當高的一致性，但是在不同人之間的指甲阻抗差異卻相當大。然而我們仍發現此平台分辨雞眼跟疣的潛力。 此自製系統可用於組織分辨，術中分析之初步模型也可行，而且平台需針對不同組織修正電極。Since bioimpedance measurement is low cost, simple, and easy-to-use, it has been used to analyze biological tissues. This thesis is focused on measurement platform to satisfy the requirements for different biological materials. A pilot model for in vitro transurethral resection of the prostate procedure was built to monitor the changes of urethra diameter and blood leakage. The correlation between the diameters of the cylinders and the measured impedance is high. Also blood leakage, as simulated by the injection of saline can be detected by the platform. The relation between diameter and impedance is compatible with previous report [1]. In addition, we use the system to identify the characteristics of verruca and clavus in multi-frequencies. As nails are in the range of thick stratum corneum as clavus. In the beginning, we measured nail as a feasibility test. The consistency of measured impedance between each individual nail is relatively high, but the variation of different subjects is much larger than within an individual. Nevertheless, we can find the potential of identifying verruca and clavus in capacitive component of impedance. The proposed system is capable for tissue characterization and the pilot model for intra-operative monitoring is workable. The platform can be adapted with different kinds of electrodes for various tissues measurement