臨床移動式漫反射光譜系統之建構與實測

Abstract

臨床上，食道組織是否癌前病變，是藉由經專業訓練的醫生透過內視鏡視診，以及侵入式的切片方式，來診斷出組織的病灶。本研究希望透過非侵入性光學診斷的方式，避免病人的疼痛或傷口感染，得到可靠的光學參數協助醫生診斷。許多文獻指出，利用漫反射光譜或其它光譜技術，如螢光光譜、光散射光譜等，可萃取出組織之光學參數，可區分正常或病變的組織，如口腔、大腸結腸、皮膚、子宮頸、乳房組織等，提供一個可靠資訊協助醫療人員診斷。 本研究主旨是建構一個臨床上移動式光譜儀系統，並用多模光纖束提供以不同的光源光纖跟偵測光纖的距離下之漫反射光譜資訊，再透過漫反射光譜擬合工具進行組織光學參數之萃取，應用於臨床研究之量測系統。 本系統以驗證過後的蒙地卡羅順向模擬光譜進行組織漫反射光譜校正，利用逆向蒙地卡羅來精準的擬合校正完的組織光譜，根據目前本系統實際量測擬組織仿體的結果，SDS(source to detection separation)於0.24、0.26、0.49、0.54、0.76、0.78mm之偵側光纖得之漫反射光譜與模擬光譜在400至700nm的線性回歸R2(R Square)可達0.9以上水準。於正常人口腔黏膜組織量測漫反射光譜的結果中，和前人研究文獻提及於波長414、545、575nm處血紅素吸收的情形以及吸收與散射係數的擬合結果亦相當接近，故本系統亦可利用此些資訊進行癌前病變組織統計與分析。 預期本系統未來可以直接用於食道組織的量測，並期許用逆向蒙地卡羅來精準的擬合所量測到的組織光譜，來萃取或比對出組織的光學參數，如散射係數、吸收係數、血紅蛋白濃度、血氧比、膠原蛋白濃度及上皮層厚度等。

The research is to construct a portable diffuse reflectance spectroscopy system that measures diffuse light using a multi-mode optical fiber bundle with different source to detector fiber distances, and using fitting tools to extract tissue optical parameters from the diffuse reflectance spectra for use as a clinical research measurement system. Clinically, diagnosis of esophageal tissue dysplasia is performed by professionally trained doctors by endoscope visual examination and invasive tissue biopsies. This study hopes, by way of non-invasive optical diagnostics, to avoid patient's pain or wound infection and provide reliable optical parameters to aid in doctor’s diagnoses. Many literature has shown that the use of diffuse reflectance spectroscopy or other spectroscopic techniques, such as fluorescence spectroscopy and light scattering spectroscopy, can extract a set of optical parameters as well as distinguish between normal or diseased tissue, such as oral, colon, skin, cervix, and provide reliable diagnostic information to assist medical personnel. The system uses a verified forward Monte Carlo simulated spectrum to correct the tissue diffuse reflectance spectra. According to the results of tissue phantoms measured using the current system, diffuse reflectance spectra’s of SDS distances of 0.24, 0.26, 0.49, 0.54, 0.76, and 0.78mm between wavelengths of 400 to 700nm show R Square values up to more than the 0.9 standard. In normal oral tissue diffuse reflectance spectra fitting results, for wavelengths 414, 545, and 575nm, hemoglobin uptake and absorption, and scattering coefficients are very close to those reported in previous literature. Thus, these systems can take advantage of this information for precancerous lesions statistical analysis. In the future, the system can be expected to directly measure esophageal tissue and use reverse Monte Carlo for precise fit of the measured spectrum to extract or compare tissue optical parameters such as the scattering coefficient, absorption coefficient, hemoglobin concentration, oxygen ratio, collagen concentration and thickness of the mucosal membrane.