Abstract：The traditional tongue inspection method should be urgently improved due to the relative large diagnosis error probability caused by the excessive dependence on the Chinese physician’s experience and judgment. But the application of tongue diagnosis based on image processing is limited by some factors including the performance of light source, image acquisition device and the low recognition rate of similar color for different diseases. In order to overcome these drawbacks, the spectroscopy method was employed to analyze the tongue by using the unique fingerprint effect of tongue spectrum. A spectrometer for tongue diagnosis (STD) was developed to achieve this goal in this paper. Meanwhile, to overcome the shortcomings of traditional light-splitting devices, a plane holographic concave grating was used as the diffractive grating, which not only can improve the luminous flux efficiency and miniaturize system, but also improve the spectral imaging quality and resolution. Experimental results demonstrated that the spectral range of STD reached 340～850 nm, and its spectral resolution is better than 2 nm. And the result of simulation experiment validated the feasibility of spectrometer’s system.
[1] WU Xi-liang, LU Xiao-zuo (伍喜良，陆小左). Tianjin Journal of Traditional Chinese Medicine(天津中医药), 2005, 22(5): 388. [2] YUAN Lin-lin, LI Wen-shu, YAO Jian-fu(苑琳琳, 李文书, 姚建富). Acta Universitatis Traditionis Medicalis Sinensis Pharmacologiaeque Shanghai(上海中医药大学学报), 2011, 25(2): 80. [3] Zhi L, Zhang D, Yan JQ, et al. Computerized Medical Imaging and Graphics，2007, 31(8): 672. [4] Fei Zhang, Tashpolat Tiyip, Jianli Ding, et al. Environmental Monitoring and Assessment，2012, 184(8): 5105. [5] Virginia G C, María T S, Juan F N, et al. Food Analytical Methods，2012, 5(6): 1377. [6] Firdous S, Nawaz M, Ahmed M, et al. Laser Physics, 2012, 22(6): 1090. [7] KONG Meng, ZENG Chang-chun, LIU You-zhang(孔 猛, 曾常春, 刘友章). Journal of Chinese Integrative Medicine(中西医结合学报)，2011，9(1): 29. [8] LIN Ling, ZHANG Jing, XIE Xin(林 凌, 张 晶, 解 鑫). Nanotechnology and Precision Engineering(纳米技术与精密工程)，2010, 8(1): 54 [9] LI Chao-ming , WU Jian-hong, ZHAO Yan-jiao(李朝明, 吴建宏, 赵艳皎). Journal of Optoelectronics·Laser(光电子·激光)，2006, 17(7): 828. [10] LI Chang-hou(李昌厚). Ultraviolet and Visible Spectrophotometer and Its Application(紫外-可见分光光度计及其应用). Beijing：Chemical Industry Press(北京：化学工业出版社)，2010. [11] LIU Yu-juan, CUI Ji-cheng, Bayanheshig(刘玉娟, 崔继承, 巴音贺希格). Optics and Precision Engineering(光学精密工程)，2012，20(1): 52. [12] Xia Guo, Qu Bixiang, Liu Peng, et al. Chinese Optics Letters, 2012，10(8): 081201.
