乾癬是一種常見於成人與兒童的慢性皮膚發炎性疾病，據研究指出大概有0.5-1%的兒童，以及世界總人口的2-3%患有乾癬。乾癬的成因複雜，遺傳、壓力、傷口等原因都有可能會引發乾癬。乾癬是一種免疫失調的疾病，通常乾癬難以根治，會伴隨患者終生。
乾癬疾病容易造成皮膚發炎，血管增加。常見的乾癬病徵為在皮膚外觀紅腫，帶有白色鱗狀皮屑。目前乾癬的診斷方法主要仰賴醫師的診斷經驗，並以皮膚鏡輔助診斷。一種量化性的病情診斷方法為Psoriasis area and severity index(PASI)。PASI由醫師以頭部、上肢、軀幹、下肢病灶的覆蓋面積、嚴重度如發紅、鱗屑、厚度做全身性的評估乾癬的病情。PASI的評估依賴視覺，在評分上比較主觀，因此我們希望能以漫反射光譜量測血紅素、散射係數、發炎程度來輔助乾癬的病情評估。
漫反射光譜學(Diffuse Reflectance Spectroscopy, DRS)是一種表層皮膚的光學量測方式，具有非侵入式與快速量測的優點。本研究使用非侵入式漫反射系統搭配兩台高精密光譜儀分析500-1400nm的漫反射光譜訊號，可快速量測多種人體生理狀況參數。
本研究在人體量測方面漫反射光譜法中，以三個角度對乾癬受測者的患部與正常的對照部位做比較。第一種是參考以光學量測發炎組織的980nm束縛水光譜討論方式，用來量測乾癬組織，並將討論波長推廣至1400nm的波段。第二種方式為使用散射係數討論乾癬表層皮膚的結構變化，並將討論波長延伸至1350nm。第三種方式為使用吸收係數搭配色團擬合來計算血紅素，並與現有的紅色素非侵入式量測儀器做對比。我們發現這三種方式皆可用於鑑別乾癬患部與對照部位的不同，且具有統計上的顯著差異。透過本研究分析，漫反射光譜法所提供的生理資訊，可做為快速、簡便的乾癬病情參考依據。

In this study, we measured 19 psoriasis subjects by diffuse reflectance spectroscopy(DRS) with 500-1400nm. We analyzed the skin characteristics of psoriasis in three ways, and obtained significant differences between the psoriasis part and the adjacent normal part. Absorption spectrum analysis can be used to understand the changes in the characteristics of water in the psoriasis area. We calculated the differences between the affected part and the adjacent normal part by t-test (p = 9*E-5). Scattering coefficient can understand changes in skin structure. We calculated the differences between the affected part and the adjacent normal part by t-test to get a significant difference. Nine of the 19 subjects were measured by the DRS system for total hemoglobin in the adjacent normal part (r=0.96) and the commercially available device had a good correlation coefficient. DRS can measure not only total hemoglobin but Hb and HbO2. We confirmed that both Hb and HbO2 of psoriasis part are higher than of normal part. We analyze psoriasis in three ways to distinguish from adjacent normal part, which can be used to assist in the study of psoriasis.

[1] M. Egawa and T. Kajikawa, "Changes in the depth profile of water in the stratum corneum treated with water," Skin Research and Technology, 2009, 15, 2, 242-249.
[2] F. Adolf Friedrich, "Optical coherence tomography," Journal of biomedical optics, 1996, 1, 2, 157-173.
[3] S.-H. Tseng, A. Grant, and A. J. Durkin, "In vivo determination of skin near-infrared optical properties using diffuse optical spectroscopy,"Journal of biomedical optics, 2008, 13, 1, 014016-014016.
[4] S. J. Matcher, M. Cope, and D. T. Delpy, "In vivo measurements of the wavelength dependence of tissue-scattering coefficients between 760 and 900 nm measured with time-resolved spectroscopy," Applied Optics, 1997, 36, 1, 386-396.
[5] T. J. Farrell, M. S. Patterson, and B. Wilson, "A diffusion theory model of spatially resolved, steady-state diffuse reflectance for the noninvasive determination of tissue optical properties in vivo," Medical Physics, 1992, 19, 4, 879-888.
[6] T. H. Pham, O. Coquoz, J. B. Fishkin, E. Anderson, and B. J. Tromberg, "Broad bandwidth frequency domain instrument for quantitative tissue optical spectroscopy," Review of Scientific Instruments, 2000, 71, 6, 2500-2513.
[7] P. Antonio, S. Johannes, C. Ekaterine, T. Alessandro, T. Paola, B. Andrea Li, A.-E. Stefan, and C. Rinaldo, "Spectroscopic time-resolved diffuse reflectance and transmittance measurements of the female breast at different interfiber distances," Journal of biomedical optics, 2004, 9, 6, 1143-1151.
[8] S.-H. Tseng, P. Bargo, A. Durkin, and N. Kollias, "Chromophore concentrations, absorption and scattering properties of human skin in-vivo,"Optics express, 2009, 17, 17, 14599-14617.
[9] R. M. Doornbos, R. Lang, M. C. Aalders, F. W. Cross, and H. J. Sterenborg, "The determination of in vivo human tissue optical properties and absolute chromophore concentrations using spatially resolved steady-state diffuse reflectance spectroscopy,"Physics in medicine and biology, 1999, 44, 4, 967-981.
[10] M. Strojnik and G. Paez, "Spectral dependence of absorption sensitivity on concentration of oxygenated hemoglobin: pulse oximetry implications,"Journal of biomedical optics, 2013, 18, 10, 108001.
[11] M. Augustin, G. Glaeske, M. A. Radtke, E. Christophers, K. Reich, and I. Schäfer, "Epidemiology and comorbidity of psoriasis in children,"The British journal of dermatology, 2010, 162, 3, 633-636.
[12] R. Parisi, D. P. M. Symmons, C. E. M. Griffiths, and D. M. Ashcroft, "Global Epidemiology of Psoriasis: A Systematic Review of Incidence and Prevalence," Journal of Investigative Dermatology, 2013, 133, 2, 377-385.
[13] L. Dubertret, U. Mrowietz, A. Ranki, P. C. M. Van De Kerkhof, S. Chimenti, T. Lotti, G. Schäfer, and E. p. survey, "European patient perspectives on the impact of psoriasis: the EUROPSO patient membership survey," British Journal of Dermatology, 2006, 155, 4, 729-736.
[14] J. L. Harden, J. G. Krueger, and A. M. Bowcock, "The immunogenetics of Psoriasis: A comprehensive review,"Journal of Autoimmunity, 2015, 64, 66-73.
[15] L. Rousset and B. Halioua, "Stress and psoriasis,"International Journal of Dermatology, 2018, 57, 10, 1165-1172.
[16] S. R. Feldman, M. Malakouti, and J. Y. Koo, "Social impact of the burden of psoriasis: effects on patients and practice,"Dermatology Online Journal, 2014, 20, 8.
[17] N. Ayala-Fontánez, D. C. Soler, and T. S. McCormick, "Current knowledge on psoriasis and autoimmune diseases,"Psoriasis (Auckland, N.Z.), 2016, 6, 7-32.
[18] W. B. Kim, D. Jerome, and J. Yeung, "Diagnosis and management of psoriasis,"Canadian family physician Medecin de famille canadien, 2017, 63, 4, 278-285.
[19] F. O. Nestle, D. H. Kaplan, and J. Barker, "Psoriasis," New England Journal of Medicine, 2009, 361, 5, 496-509.
[20] T. E. Christensen, K. P. Callis, J. Papenfuss, M. S. Hoffman, C. B. Hansen, B. Wong, J. M. Panko, and G. G. Krueger, "Observations of Psoriasis in the Absence of Therapeutic Intervention Identifies Two Unappreciated Morphologic Variants, Thin-Plaque and Thick-Plaque Psoriasis, and their Associated Phenotypes," Journal of Investigative Dermatology, 2006, 126, 11, 2397-2403.
[21] T. Fredriksson and U. Pettersson, "Severe psoriasis--oral therapy with a new retinoid,"Dermatologica, 1978, 157, 4, 238-244.
[22] S. H. Chung, A. E. Cerussi, C. Klifa, H. M. Baek, O. Birgul, G. Gulsen, S. I. Merritt, D. Hsiang, and B. J. Tromberg, "In vivo water state measurements in breast cancer using broadband diffuse optical spectroscopy,"Physics in medicine and biology, 2008, 53, 23, 6713-6727.
[23] 郭俊言, "研究具有調整雙層式或傳統式量測架構配置的平台式與手持式漫反射光譜系統之性能表現," 07 2015.
[24] "Monte Carlo Modeling of Photon Transport in Biological Tissue," in Biomedical Optics, pp. 37-65.
[25] L. Wang, S. L. Jacques, and L. Zheng, "MCML—Monte Carlo modeling of light transport in multi-layered tissues," Computer Methods and Programs in Biomedicine, 1995, 47, 2, 131-146.
[26] T. Binzoni, T. S. Leung, A. H. Gandjbakhche, D. Rüfenacht, and D. T. Delpy, "The use of the Henyey-Greenstein phase function in Monte Carlo simulations in biomedical optics,"Physics in medicine and biology, 2006, 51, 17, N313-322.
[27] Y.-W. Chen and S.-H. Tseng, "Efficient construction of robust artificial neural networks for accurate determination of superficial sample optical properties," Biomedical Optics Express, 2015, 6, 3, 747-760.
[28] C.-K. Hsu, S.-Y. Tzeng, C.-C. Yang, J. Y.-Y. Lee, L. L.-H. Huang, W.-R. Chen, M. Hughes, Y.-W. Chen, Y.-K. Liao, and S.-H. Tseng, "Non-invasive evaluation of therapeutic response in keloid scar using diffuse reflectance spectroscopy,"Biomedical Optics Express, 2015, 6, 2, 390-404.
[29] V. H. Segtnan, Š. Šašić, T. Isaksson, and Y. Ozaki, "Studies on the Structure of Water Using Two-Dimensional Near-Infrared Correlation Spectroscopy and Principal Component Analysis," Analytical Chemistry, 2001, 73, 13, 3153-3161.
[30] M. Tarumi, M. Shimada, T. Murakami, M. Tamura, M. Shimada, H. Arimoto, and Y. Yamada, "Simulation study of in vitro glucose measurement by NIR spectroscopy and a method of error reduction,"Physics in medicine and biology, 2003, 48, 15, 2373-2390.
[31] "http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html."
[32] G. E. Walrafen and E. Pugh, "Raman Combinations and Stretching Overtones from Water, Heavy Water, and NaCl in Water at Shifts to ca. 7000 cm−1," Journal of Solution Chemistry, 2004, 33, 1, 81-97.
[33] M. Gniadecka, O. Faurskov Nielsen, D. H. Christensen, and H. C. Wulf, "Structure of water, proteins, and lipids in intact human skin, hair, and nail,"Journal of Investigative Dermatology, 1998, 110, 4, 393-398.
[34] J. P. Wold, I. Måge, A. Løvland, K. W. Sanden, and R. Ofstad, "Near-infrared spectroscopy detects woody breast syndrome in chicken fillets by the markers protein content and degree of water binding,"Poultry Science, 2019, 98, 1, 480-490.
[35] A. R. Matias, M. Ferreira, P. Costa, and P. Neto, "Skin colour, skin redness and melanin biometric measurements: comparison study between Antera® 3D, Mexameter® and Colorimeter®," Skin Research and Technology, 2015, 21, 3, 346-362.
[36] S. Janis and O. Ilze, "Snapshot RGB mapping of skin melanin and hemoglobin," Journal of biomedical optics, 2015, 20, 5, 1-3.
[37] J. Welzel, M. Bruhns, and H. H. Wolff, "Optical coherence tomography in contact dermatitis and psoriasis," Archives of Dermatological Research, 2003, 295, 2, 50-55.
[38] H. I. M. Marie Loden, Dry Skin and Moisturizers: Chemistry and Function citation. CRC Press, 1996.