A detection method of lateral resolution of ophthalmic oct equipment based on dwpso algorithm

Abstract

The invention discloses a method for detecting the lateral resolution of ophthalmic OCT equipment based on a DWPSO algorithm, belonging to the field of medical optical detection. This method first uses the beam space transmission characteristics to establish the beam intensity distribution model of ophthalmic OCT equipment; then extracts the edge features of the beam spot and performs ellipse fitting, and uses the fitting parameters as reference parameters to determine the optimization space of the DWPSO algorithm. The weight factor adjusts the particle update speed of the DWPSO algorithm, and then uses the DWPSO algorithm to identify the beam width parameters of the beam intensity distribution model; finally, the least squares algorithm is used to fit the beam width and obtain the beam divergence angle, and then calculate the lateral resolution of the ophthalmic OCT equipment. This method uses the DWPSO algorithm to identify the parameters of the light intensity distribution model of the ophthalmic OCT equipment beam, effectively reducing the impact of spot interference fringes on the detection accuracy of the lateral resolution, and has a higher detection accuracy of the lateral resolution.

Description

technical field [0001] The invention relates to a method for detecting the lateral resolution of ophthalmic OCT (Optical Coherence Tomography) equipment, belonging to the field of medical optical detection, and in particular to a method for detecting the lateral resolution of ophthalmic OCT equipment based on the DWPSO (Dynamic Weight Particle SwarmOptimization) algorithm. Background technique [0002] OCT imaging technology has been applied to the medical detection and diagnosis of subtle ocular lesions. The lateral resolution of ophthalmic OCT equipment is one of its key parameters, which directly affects the imaging quality of ophthalmic OCT equipment for subtle ocular lesions and the diagnostic results of ocular lesions. [0003] The existing lateral resolution detection methods of ophthalmic OCT equipment mainly include: resolution plate method, point spread function method and beam focusing characteristic method. The resolution plate method is limited by the line widt...

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Problems solved by technology

The resolution plate method is limited by the line width of the target plate pattern, which makes the detection accuracy of the lateral resolution of the ophthalmic OCT equipment low; although the point spread function method can realize the accurate quantification of the lateral resolution of the ophthalmic OCT equipment, it is limited by the midpoint of the substrate material. Due to the influence of the particle size, mixing degree and processing technology of the diffusion function, it is difficult to prepare a point spread function phantom that meets the requirements, which directly affects the detection accuracy of the lateral resolution, and it is necessary to prepare different point spread function phantoms for different ophthalmic OCT equipment , which restricts its application in the detection of lateral resolution of ophthalmic OCT equipment; the beam focusing characteristic method uses Rayleigh width or beam numerical aperture to realize the detection of lateral resolution of ophthalmic OCT equipment, although it can overcome the defects of the above methods, but the Rayleigh width Higher requirements for single-point measurement accuracy lead to greater difficulty in implementation. Although the use of numerical aperture can avoid the defect that Rayleigh width requires too high single-point measurement accuracy through multi-point fitting, it can achieve micron horizontal resolution of ophthalmic OCT equipment. Level detection, but the horizontal resolution detection results are more sensitive to the interference fringes existing in the beam spot of the ophthalmic OCT equipment, resulting in poor consistency of the horizontal resolution detection results, and it is difficult to improve the detection accuracy

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