The Design And Study Of Sheath Flow System And Optical System For Flow Cytometry

Flow cytometry is a device which can do analysing and sorting for cells, which is widely used in clinical medicine, basic medical research, cytobiology and so on. At present the development of the flow cytometry is relatively backward at home, and there is not a truly flow cytometry belong to china, so the research of flow cytometry is more important. This paper makes the design and analysis for the sheath flow system, laser-beam shaping system, the detecting system of forward scattering light and side light and the detecting system of fluorescence signal for the flow cytometry.In order to make the sample flow with a certain width and linear state under being wraped by the sheath liquid go through laser detection zone, this paper designs the sheath flow system through Solidworks software based on the theory of hydrodynamic focusing, the common sheath flow system and the requirement of structure about flow cytometry. We verify the correctness of the structure of sheath flow system by Solidworks flow simulation software, analysing the factor of the sample flow focusing.In the laser detection zone, this paper designs the laser beam-shaping system which can make the laer-beam form a 10?mx75?m elliptic spot whose energy distribution is uniform by Zemax software based on the characteristics of cylindrical lens in order to make the cell samples have sufficient illumination of the excitation source, then we verify the correctness of the optical structure by Optisworks software. Because the deviation of the position of element in the laer-shaping system has influence on the focused spot, we determine the error tolerance of element by Zemax software. Considering that the deviation of position of the capillary with respect to the flow chamber will impact on the foucesed spot, we summarize the method of adjusting optical structure by Optisworks software.Based on the detecting requirements of silicon photocell and the characteristics of scattered light, we design the optical structure of detecting the scattered light of forward small angle and side 90 degrees by Zemax software. In order to discuss the relationship between the scattered light and cell structure, we do the specific analysis of the relationship between the scattered light of forward small angle and the cell size by Optisworks software. Through constructing the model of the internal structure of cell, we do the specific analysis of the relationship between the scattered light of side 90 degrees and the internal structure of cell by Optisworks software.Based on the detecting requirements of the silicon photomultiplier and the characteristics of fluorescence signal, we design the optical structure of detecting fluorescence by Zemax software. We do the specific analysis of the change of spot on the detector of fluorescence in order to discuss the influence about the detection of fluorescence signal when there is deviation of the cell samples with respect to the center of the sample needle when it goes through the laser detection zone. Because of the weak of the fluorescence signal and the stray light which will be produced by the whole system, we finally discusse the influence of the stray light on the fluorescence signal.