漫反射光譜法(Diffuse Reflectance Spectroscopy, DRS)是一種可非侵入且迅速獲得皮膚內如黑色素濃度、組織血氧等生理資訊的光學技術，其廣泛應用於各醫療領域中。目前DRS技術使用的演算法多數是採用均質模型，然而皮膚為多層結構，以均質模型量化得的色團濃度無法非常準確，目前應用皆為提供相對的色團濃度變化結果。因此，我們在本研究中發展雙層漫反射光譜演算法以獲得更準確的色團濃度。本研究透過GPU版蒙地卡羅法來建構大量雙層組織的漫反射光譜資料庫，再搭配人工類神經網路來進行雙層結構分類分析，並且為因應探討不同的皮膚結構而發展兩種雙層漫反射模型，分為上皮層-皮下脂肪層雙層模型與表皮層-真皮層雙層模型兩種分析方法，分別量化真皮層厚度與表皮層厚度、黑色素濃度、血液濃度。本研究透過模擬與仿體實驗來檢驗兩種雙層分析方法的可行性，並且以高頻超音波作為比較標準進行實際人體皮膚厚度量測。上皮層-皮下脂肪層雙層方法的人體實驗結果中，上層厚度最大誤差為21%(超音波結果1.8毫米;本研究的分析結果1.42毫米)，最佳結果誤差為12%(超音波結果1.8毫米;本研究的分析結果1.58毫米)。至於表皮層-真皮層雙層模型分析方法的模擬驗證中，我們的雙層分析方法與均質模型相比可更準確量化色團濃度，雙層分析方法量化黑色素濃度與血液濃度最佳誤差為3%與2%，而均勻模型則為86%與15%，都有相當顯著的優化。綜合上述各點，本研究提出兩種的雙層分析方法不但具有高計算效率(2秒與0.4秒)，準確性也有顯著的提升，可快速量化人體皮膚表皮層、真皮層厚度與黑色素濃度、血液濃度，極具作為臨床皮膚生理資訊分析的潛力。

To accurately investigate skin chromophore concentrations and thickness, we need to evolved layered diffuse reflectance spectroscopy (DRS) models. Most of all light transport model of DRS used was supposed that the media is homogenous. It is a challenge that using homogenous model to quantify chromophore concentration when the sample structure is layered, like human skin. We present two two-layered models for different skin structure. First one is dermis-subcutaneous model and it was designed to acquire dermis thickness. The second one is epidermis-dermis model and it was deigned to accurately investigate concentration of melanin and blood. Using GPU Monte Carlo construed the database. The database for dermis-subcutaneous model were 45738 kinds of two-layer reflectance. The database for epidermis-dermis model were 2050 kinds of absorption spectra of two-layer model with homogenous ANN. By simulated and liquid phantom experiment, we verified both two-layer models could investigate its’ target. At human experiment, we compare epidermis and dermis thickness by our two-layer models with ultrasound measurement. We also compare the concentration by homogenous model with by our two-layer model. For dermis-subcutaneous model human experiment, the difference of our two-layer model and ultrasound measurement was less than 0.3 mm at two of three subjects. For epidermis-dermis model, our epidermis-dermis two-layer model was most accurately quantification of chromophore concentrations model with our system at simulated experiment. The time required of two two-layer models were 2s and 0.4s. Using our two-layer models can accurately investigate skin chromophore concentrations and thickness in the short time.

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