Abstract:  In this paper, a specific identification method for human nail fold based on polarization-sensitive optical coherence tomography is presented. This method can be used to quickly and accurately identify the microstructure and determine the structural state of nail and surrounding skin tissue. Images of polarization parameters and curves of corresponding parameters as a function of depth of tissue guided by the theory of multiple polarization parameters are obtained based on the polarization optical coherence tomography system; on the basis of fully analyzing the theoretical model of multi-polarization parameters of tissue and image data, polarization parameters with high sensitivity to different parts of tissue are determined and selected; the degree of correlation between different polarization parameters with clear physical significance and the microstructure of nail and surrounding skin tissue is revealed. Finally, marking parameters for locating nail plate, monitoring parameters of the status of nail plate and identifying parameters of boundaries between nail plate and nail bed are defined. These are the meaningful set of parameters for distinguishing the human nail fold from the surrounding structures. These results can be used to assist doctors to complete the large-scale monitoring of nail and surrounding skin tissue and the efficient identification and analysis of small-scale microstructure.
Key words: Mueller matrix; PS-OCT; retardance; Stokes vector; nail and surrounding skin tissue; polarization determination method
（Acta Laser Biology Sinica, 2025, 34(2): 140-147）