What we do

To develop portable devices that can be used by both healthcare professionals and consumers to monitor their overall health status via diffuse reflectance spectroscopy(DRS) systems.



We design DRS modules
that can detect
reflected light from skin.

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Programming Console


We develop novel
photon diffusion models to investigate superficial tissues

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What can DRS system do?


DRS system can accurately calculate the absorption and scattering characteristics of light in tissues and quantify physiological tissue parameters.







Blood glucose variation

TLS PATENT Portfolio 



  • “Investigation of water bonding status of normal and psoriatic skin in vivo using diffuse reflectance spectroscopy”, Chao-Chun Yang, Yun-Yo Yen, Chao-Kai Hsu, Nan-Yu Cheng, Shih-Yu Tzeng, Shih-Jay Chou, Jun-Ming Chang, and Sheng-Hao Tseng*, Scientific Reports, 11, 8901, (2021).

  • “Noninvasive transcutaneous bilirubin assessment of neonates with hyperbilirubinemia using a photon diffusion theory-based method”, Nan-Yu Cheng, Yi-Ling Lin, Ming-Chien Fang, Wen-Hsien Lu, Chin-Chieh Yang, and Sheng-Hao Tseng*, Biomedical Optics Express, 10(6), 2969-2984, (2019).

  • “Skin collagen can be accurately quantified through noninvasive optical method: Validation on a swine study”, Shih-Yu Tzeng, Ting-Yung Kuo, Shao-Bu Hu, Yu-Wen Chen, Yi-Ling Lin, Kang-Yu Chu, Sheng-Hao Tseng*, Skin Research and Technology, 00:1-6, (2017).

  • “Light distribution modulated diffuse reflectance spectroscopy”, Pin-Yuan Huang, Chun-Yu Chien, Chia-Rong Sheu, Yu-Wen Chen, and Sheng-Hao Tseng*, Biomedical Optics Express, 7(6), 2118-2129, (2016).

  • “Artificial neural networks for retrieving absorption and reduced scattering spectra from frequency-domain diffuse reflectance spectroscopy at short source-detector separation”, Yu-Wen Chen, Chien-Chih Chen, Po-Jung Huang, and Sheng-Hao Tseng*, Biomedical Optics Express, 7(4), 1496-1510, (2016).​

  • “Portable handheld diffuse reflectance spectroscopy system for clinical evaluation of skin: a pilot study in psoriasis patients”, Shih-Yu Tzeng, Jean-Yan Guo, Chao-Chun Yang, Chao-Kai Hsu, Hung Ji Huang, Shih-Jie Chou, Chi-Hung Hwang, and Sheng-Hao Tseng*, Biomedical Optics Express, 7(2), 616-628, (2016).

  • “Toward reliable retrieval of functional information of papillary dermis using spatially resolved diffuse reflectance spectroscopy”, Yu-Wen Chen , Jun-Yen Guo, Shih-Yu Tzeng, Ting-Chun Chou, Ming-Jen Lin, Lynn Ling-Huei Huang, Chao-Chun Yang, Chao-Kai Hsu, and Sheng-Hao Tseng*, Biomedical Optics Express, 7(2), 542-558, (2016).

  • “Efficient construction of robust artificial neural networks for accurate determination of superficial sample optical properties”, Yu-Wen Chen and Sheng-Hao Tseng*, Biomedical Optics Express, 6(3), 747-760, (2015).

  • “Broadband absorption and reduced scattering spectra of in-vivo skin can be noninvasively determined using δ-P1 approximation based spectral analysis”, Cheng-Hung Hung, Ting-Chun Chou, Chao-Kai Hsu, and Sheng-Hao Tseng*, Biomedical Optics Express, 6(2), 443-456, (2015).

  • “Non-invasive evaluation of therapeutic response in keloid scar using diffuse reflectance spectroscopy”, Chao-Kai Hsu, Shih-Yu Tzeng, Chao-Chun Yang, Julia Yu-Yun Lee, Lynn Ling-Huei Huang, Wan-Rung Chen, Michael Hughes, Yu-Wen Chen, Yu-Kai Liao, and Sheng-Hao Tseng*, Biomedical Optics Express, 6(2), 390-404, (2015).

  • “A linear gradient line source facilitates the use of diffusion models with high order approximation for efficient, accurate turbid sample optical properties recovery”, Ming-Wei Lee, Cheng-Hung Hung, Jung-Li Liao, Nan-Yu Cheng, Ming-Feng Hou, and Sheng-Hao Tseng*, Biomedical Optics Express, 5(10), 3628-3639, (2014).

  • “Reliable recovery of the optical properties of multi-layer turbid media by iteratively using a layered diffusion model at multiple source-detector separations”, Yu-Kai Liao and Sheng-Hao Tseng*, Biomedical Optics Express, 5(3), 975-989, (2014).

  • “Higher-order modulations of fs laser pulses for GHz frequency domain photon migration system”, Huang-Yi Lin, Nanyu Cheng, Sheng-Hao Tseng, and Ming-Che Chan, Optics Express, 22(4), 3950-3958, (2014).​

  • “Noninvasive evaluation of collagen and hemoglobin contents and scattering property of in-vivo keloid scars and normal skin using diffuse reflectance spectroscopy: pilot study”, Sheng-Hao Tseng*, Chao-Kai Hsu, Julia Yu-Yun Lee, Shih-Yu Tzeng, Wan-Rung Chen, and Yu-Kai Liaw, Journal of Biomedical Optics, 17(7):077005, (2012).

  • “Efficient determination of the epidermal optical properties using a diffusion model–based approach: Monte Carlo studies”, Sheng-Hao Tseng* and Ming-Feng Hou, Journal of Biomedical Optics, 16(8):087007, (2011).

  • “Analysis of a diffusion-model-based approach for efficient quantification of superficial tissue properties”, Sheng-Hao Tseng* and Ming-Feng Hou, Optics Letters, 35(22), 3739-3741, (2010).

  • “Chromophore Concentrations, Absorption and Scattering Properties of Human Skin In-vivo”, Sheng-Hao Tseng*, Paulo Bargo, Anthony Durkin, and Nikiforos Kollias, Optics Express, 17(17), 14599-14617, (2009).

  • “Investigation of a probe design for facilitating the uses of the standard photon diffusion equation at short source-detector separations: Monte Carlo simulations”, Sheng-Hao Tseng*, Carole Hayakawa, Jerome Spanier, and Anthony J. Durkin, Journal of Biomedical Optics, 14(5):054043, (2009).