Dynamic Effects And Its Countermeasure In Tomography Of Biological Cells

As a basic unit of organism, the cell’s status is related to genetics, disease,immunity and rehabilitation closely. As for individual cell, the morphological characteristics as well as internal composition which plays a crucial role in its health status, function and activity. Thus it is extremely important to research the size and morphology of the cell in biological cytology, life science and other fields. It is an important topic to detect the cell quantitatively in various fields. There are many techniques for cell imaging and they have their own feature and advantages respectively. So we need to select an appropriate imaging method based on the actual situation. According to the imaging theory, the methods can be divided into interferometric phase measurement and non-interferometric phase measurement.Computer tomography is a technology, which reconstructs the internal structure of the object based on the transmitted field data from multiple angles. However, in interferometric phase imaging technology, since the thickness and refractive index of the sample are coupled together, sub-structure of heterogeneous sample cannot be well expressed. In addition, due to the impact of diffraction, the resolution of interference pattern is restrained. For imaging reconstruction technique, the process is often time-consuming and quantitative characterization of the quality of the reconstruction is still not perfect.In response to the questions above, this paper was supported by 3D feature recognition methods and techniques of sub-surface of nucleated cells in orthonormal phase of National Natural Science Foundation of China(11374130), global optical phase image analysis methods and techniques of electro-discharge dynamic behavior of neurons from National Natural Science Foundation of China(11474134), optical detection method of the instant identification of biological cells based on the digital phase distribution from Natural Science Foundation of Jiangsu Province(BK20141296), and 3D reconstruction of sub-structure of blood cell based on dual optical phase information from the program of ”six kinds of talents of JiangsuProvince”(2015 DZXX-023), and so on. In addition, through reading and analyzing many materials of this field published recently, the principles and characteristics of each imaging method are summarized in this paper. With the MATLAB simulation system, we establish the models of cells, and open a prelude for the analysis of characteristics of biological cells. The work of the paper is divided into the following sections:According to structural characteristics of the neuron and disc-shaped structure of the red blood cell, a similar neural model and a red blood cell model are established on the MATLAB simulation system in this paper. Appling neural model, the effects of the number of projections, the range of projective angle and the symmetric axis of the object are discussed in the computer tomography in this paper. Taking into account the presence of noise in the case of practical application, the processes of adding noise and filtering are discussed in this paper. In addition, in view of the shortcoming of the traditional evaluation parameters of image, an improved evaluation parameter is proposed and confirmed in this paper.Quantitative phase imaging technology has achieved encouraging results not only in the speed of data acquisition but also in terms of spatial resolution. However,due to the effect of integration between refractive index and optical path, we lost details of optical axis direction. Therefore, quantitative phase imaging technology mainly used to observe homogeneous phase cells, but we cannot rebuild the internal structure of heterogeneous phase cells using the same method; Currently, cell detection classification technology that commonly used in clinic mostly based on light scattering theory. However the information provided by scattered light is the average within the volume to be measured, so such technology cannot get good spatial resolution. In addition, traditional detection principle is generally based on Mie scattering theory, which only can be applied to spherical model, and therefore cannot be applied to recognize other complex cells, such as white blood cell. A device that could receive scattering light and microscopic phase of the sample simultaneously is proposed in this paper. The device could receive interference patterns and scattering intensity of the sample based on coaxial Michelson interferometer and Millauinterferometer. With the help of computer, more accurate information of the sample could be obtained based on the theories of scattering and phase imaging.Because of the simple process, interferometric phase imaging technology is widely used in phase microscopy imaging. Due to the effect of diffraction, the resolution of interferometric phase imaging would be reduced. In this paper, the results of the interference and diffraction are compared on the VirtualLab simulation system.Interference imaging spectroscopy is the combination of imaging technique and spectroscopy. In practical application, the interference pattern would suddenly turned off at the maximum optical path difference, which leads to the discontinuous change in interference pattern and disturbance of the recovery spectrum. To solve the problem above, it is important to alleviate the degree of discontinuity by using appropriate measures. In this paper, four kinds of apodization functions are analysed, and provide the handled curve of experimental interferogram. The results shows that change of both sides of the interference pattern is easing.Firstly, cell models were established and analysis of the influencing factors of image reconstruction is provided innovatively in this paper. Secondly, a new device for quantitative phase imaging of the cell was provided in this paper. In addition, the results of interferometric phase imaging and diffraction phase imaging were analysed,and the experimental verification was provided in this paper. All the results above could provide a foundation for the study of the morphology of biological cell.