Application Of Modified Scattering Amplitude Complex Function In The Study Of Cell Scattering Characteristics

Cells are the basic structural and functional units of organisms.Every field of life science pays attention to the study of cell size distribution and body characteristics.In medicine,the feedback of pathogenesis,diagnosis and treatment of many diseases need to recognize the morphological characteristics of cells.Especially in the early stage of the disease,cell morphology and internal structure will change,but cell metabolites have not changed significantly,and various physiological and chemical indicators are normal.Therefore,early diagnosis from the changes of cell physical characteristics is a particularly attractive and worth exploring field.Light travels in cells,and scattered light carries information of cell structure and morphology.Using light scattering method to extract key information of scattered signal and realize label-free identification and analysis of biological cell morphology and structure has the advantages of simple operation,integration and expandability.It is a direction worthy of study.Aiming at the problem that the existing scattering theory does not apply to non-spherical inhomogeneous real cells,a double-layer eccentric sphere model for real cells is established.Based on Mie scattering theory and electromagnetic wave interface transmission theory,the key parameter under non-spherical inhomogeneous conditions,i.e.modified scattering light amplitude complex,is deduced by using geometric scattering approximation method.Modified expression of function.Finally,the modified complex function of scattering light amplitude is used to solve the scattering parameters of light scattering of two cells: the difference range of white blood cells scattering polarized light and the scattering phase function of nuclear cells.In the study of scattering characteristics of polarized light by white blood cells,Stokes-Mueller matrix elements of polarized light transmission are further modified by using the modified complex function of scattering light amplitude.Spatial distribution and correlation of scattering light intensity of granular white blood cells with different shapes,sizes and refractive index are numerically simulated based on the eccentric sphere model when two polarized beams incident polarized light perpendicular to each other.Thethree-dimensional distribution images of polarized light scattering show different fringe characteristics under different conditions,which indicates that the distribution law is correlated with the body parameters and optical parameters of the cell model.The analysis results of the difference,ratio,difference and ratio of scattering light intensity show that the backscattering of polarized light reflects more abundant structural and optical information inside the cell.In the study of scattering phase function of nucleated cells,the Mie phase function,asymmetric factor G and second-order parameter ? of nucleated cells in a single dispersion system were further modified by using the modified scattering light amplitude complex function.The effects of morphology and optical parameters of nucleated cells on the angular distribution of Mie phase function and Airy peak number were calculated.The variation of G and ? with the wavelength,cell size,nuclear-cytoplasmic ratio and refractive index of incident light was also studied.The numerical simulation was carried out.The results show that the distribution of Mie phase function,the number of Airy peaks,g and ? are not only related to the size of cells,but also to the ratio of nucleus and refractive index,so the influence of optical structure inside cells can not be neglected.Compared with HG phase function,Mie phase function can describe the backscattering characteristics and calculate g and ? more accurately,which provides further theoretical support for the study of label-free identification of cells and the transmission characteristics of laser in biological tissues.The research content of this paper is to provide more theoretical basis for the application of single-cell flow-cytometric label-free optical detection technology,and provide more excavatable optical scattering information for the realization of label-free cell classification and the screening of diseased white blood cells in practice.