Optical design of a snapshot hyperspectral imaging spectrometer for facial colour diagnosis in traditional Chinese medicine

Colour diagnosis of traditional Chinese medicine (TCM) is the main content of “looking” inspection in the four-diagnosis methods of "looking, listening, asking and feeling the pulse". The action of light on the face is a very complex process, it is difficult to distinguish reflected light from internally reflected light by human eyes alone. In this paper, we discuss the relationship between TCM facial colour diagnosis and optics, integrate imaging spectroscopy to improve the objectified development of facial colour diagnosis in TCM. A visible band snapshot hyperspectral imaging spectrometer is designed based on a grating dispersion module. This imaging spectrometer is a snapshot system with 34° field of view and a measured spectrum from 400 nm to 680 nm. The spectral resolution reaches 3nm. The total length of the optical system is only 165mm, which can realize the miniaturization of products.