CN103190886A - Novel optical method detection system for biological tissue pathological changes - Google Patents

Abstract

The invention relates to a novel optical method detection system for biological tissue pathological changes. According to the novel optical method detection system, based on analyzing non-uniform polarization structures of fields, which are scatted from biological tissues, pathological changes of birefringence biological tissues are detected through measurement of spatial distribution of field parameters of biological tissue images.

Description

A New Optical Method Detection System for Biological Tissue Lesions

technical field

The invention relates to an optical system for detecting pathological changes of biological tissues by means of singular point optics. The present invention uses coherent laser to obtain the result of correlation structure of polarization image through biological tissue, and uses the coordinate distribution measurement technology of degree of mutual polarization (DMP) to describe the topological description of uneven polarization image of biological tissue, and the result shows the S profile It is related to the half-width of the autocorrelation function of the coordinate distribution of DMP values. These information can become the basis of clinical diagnosis of biological tissue canceration.

Background technique

Today, medicine is going through a period of major change. Medicine's focus is shifting from a traditional symptom-based treatment model to an information-based one. It has been recognized that symptoms are simply a crude abnormal response of the body on which the disease is delayed. The research on some major medical topics today focuses on exploring the laws of biological information that lead to diseases from the very beginning, so as to control the biological logic information in a healthy state, and then achieve the purpose of treating diseases. To this end, new methods of medical diagnosis and treatment are being explored from various disciplines (magnetism, acoustics, chemistry, optics, etc.). Optics is currently believed to hold the promise of playing a major role in the great changes in medicine today. Understanding the law of light propagation in biological tissues, and the successful development of high-performance light sources represented by lasers and high-sensitivity optical detectors are the theoretical basis and material basis for this understanding, respectively. Although traditional optical detection and diagnosis have many advantages compared with traditional medical methods, especially the non-destructive detection and diagnosis technology in the wavelength range of 600nm to 1300nm "optical window" is booming, such as the detection of tissue blood oxygen and cerebral blood oxygen, blood Monitoring of oxygen and glucose levels. The OCT technology developed in recent years in terms of imaging technology has also been highly valued by people. However, due to the diversity and complexity of biological tissues, traditional optical detection and diagnosis technology is still unclear in theory, especially how to provide reliable physiological parameters for clinical medicine. There are many issues that require more research, and there is still room for improvement in the effectiveness and reliability of detection and treatment. On the basis of inheriting the advantages of non-contact, non-ionization, non-invasive or micro-trauma and high flexibility of traditional optical detection of diseased biological tissue, the present invention uses the singular point optical method to detect pathological diseased birefringent biological tissue, thereby being able to Provide more accurate biological tissue field parameters for clinical medicine.

Contents of the invention

In order to improve the reliability of tissue optical parameters, we propose a new optical detection system. The system is different from the traditional optical detection idea, combining the unique field structure characteristics of singularity optics, based on the analysis of the non-uniform polarization structure of the field scattered from biological tissue, by measuring the singularity polarization and mutual polarization of biological tissue images The spatial distribution of field parameters such as degree of transformation (DMP value) can be used to detect pathological lesions of birefringent biological tissues.

The technical solution of the present invention is: the measurement system is shown in Figure 1, and the light source is a collimated helium-neon laser ( λ = 0.6328 μm, W = 5.0 mw, diameter 10 mm). Polarization is controlled by quarter-wave plates 3 and 5, and polarizer 4 adjusts the angle and ellipticity of polarized light, where 0≤ α ₀ ≤180 ⁰ , 0≤ β ₀ ≤90 ⁰ . The polarized image of the biological tissue is obtained by sending the microscopic sample 7 to the CCD array 9. The pixel of the CCD is 800*600. The CCD array can provide the measurement of the lateral range from 2 to 200 microns for the biological tissue. Using the polarizer 8 an image of biological tissue can be analyzed.

Compared with other optical detection methods, the present invention can utilize the unique field structure characteristics of singularity optics to obtain the spatial distribution of polarization parameters of the field scattered by biological tissues, thereby detecting pathological lesions of birefringent biological tissues. The invention has simple structure and is easy to manufacture.

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of a new optical method detection system for biological tissue lesions.

Fig. 2 is the research object in the first embodiment.

Fig. 3 is the experimental result in the first embodiment.

Fig. 4 is the research object in the second embodiment.

Fig. 5 is the first experimental result in the second embodiment.

Fig. 6 is the second experimental result in the second embodiment.

FIG. 7 is the third experimental result in the second embodiment.

FIG. 8 is the fourth experimental result in the second embodiment.

In Fig. 1, 1 helium-neon laser, 2 collimator, 3, 5 quarter wave plate, 4, 8 polarizer, 6 research object, 7 microscopic sample, 9CCD camera, 10 processing unit.

In Fig. 2, 1 is the polarized image of myocardial tissue obtained with coaxial and 2 crossed polarizers. "P" marks the region of the investigated polarization topology.

Topological distribution of polarization singularities (S-contours) in myocardial tissue images in Fig. 3. The S state is marked with a black dot; the right-handed C point is marked with a red dot, and the left-handed C point is marked with a blue dot.

In Fig. 4, polarization images of 1 physiologically normal and 2 cancerous dermal tissues under crossed polarizers.

Coordinate distribution of the polarization ellipticity β ( r ) of 1 physiologically normal and 2 cancerous dermal tissue images in Fig. 5 .

Coordinate distributions of single degenerate and double degenerate polarization singularities of 1 physiologically normal and 2 cancerous dermal tissues in Fig. 6 .

The DMP value distribution of 1 physiologically normal and 2 cancerous dermal tissues in Fig. 7 .

The two-dimensional autocorrelation function of the DMP coordinate distribution of 1 normal and 2 cancerous dermal tissues in Fig. 8 . 3D plots of autocorrelation functions corresponding to DMP of normal and 4 cancerous dermal tissues.

Specific examples:

In the first embodiment shown in FIG. 2 , we selected a piece of myocardial tissue with a geometric thickness of 100 microns as the research object, and compared and analyzed the topological structure of the polarization non-uniform image obtained through the computer model and the experiment. Figure 3 shows the topological distribution of S-type and C-type polarization singularities, which are in the P region of myocardial tissue (see Figure 2) in the state of the light source { α ₀ =0 ⁰ ; β ₀ =0 ⁰ } obtained experimentally. The results show that all types of S-contours appear in the polarization images of myocardial tissue, which are similar to the structure of all S-contours in actual birefringent biological tissues.

In Example 2 shown in Figure 4, we studied normal and cancerous dermal tissue. 1 in Figure 4 is a microscopic image of the polarized visible structure of the dermis obtained with cross-polarized light. 2 is cancerous dermal tissue accompanied by geometrically enlarged collagen. Fig. 5 is a coordinate distribution map of the ellipticity β ( r ) of 1 normal and 2 cancerous dermal tissues. The results showed that the boundary fields of both dermal tissue samples were polarized inhomogeneously. The main feature of the image polarized structure of cancerous dermal tissue is that the geometric size of β ( r ) becomes larger. This is associated with birefringent collagen structures of increased size. In Fig. 6 we list the coordinate distribution of the polarization singularity points, and the green (representing the linear polarization state) and red (representing the left-handed and right-handed polarization states) points are superimposed on the corresponding dermal images. Fig. 7 is the coordinate distribution of DMP values calculated from 1 normal and 2 cancerous dermal tissue images. Fig. 8 depicts the autocorrelation function G (|V ² |) derived from 1 normal and 2 cancerous dermal tissue DMP coordinate distribution images. The data clearly show that the half-width of the autocorrelation function and the size of the S-contour are similar for the two dermal tissues.

Claims (2)

1. A new optical method detection system that can be used to detect pathological lesions of biological tissues, consisting of a helium-neon laser, a collimator, a quarter-wave plate, a polarizer, a research object, a microscopic sample, a CCD camera and The computer processing unit and the like are characterized in that the system can be used to obtain the polarization field of the biological tissue, so as to measure the image of the biological tissue. 2. The polarizer 8 according to claim 1, characterized in that: after the polarizer 8 is inserted into the system, the angles of the transmission axes are adjusted to Θ=0 ⁰ , Θ=90 ⁰ in turn, and the light intensity I is measured respectively ⁽⁰⁾ ( r _m , _n ), I ⁽⁹⁰⁾ ( r _m , _n ), and then change the direction of the transmission axis of the polarizer 8 in the range of Θ=0 ⁰ →180 ⁰ , and measure the received the maximum and minimum light intensity I _max ( r _m , _n ) and I _min ( r _m , _n ), and measure the corresponding rotation angle Θ( r _{m , n} )| _{I (r m , n )= I min} at the same time, and then The coordinate distribution of the optical vibration polarization state of the biological tissue and the DMP value of the biological tissue image are calculated by using the measurement data.

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