Aberration Correction Control Model of Adaptive Optics in the Fundus Imaging System
1 College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
2 Shanghai Institute of Spaceflight Control Technology, Shanghai 200233, China
Abstract：In an adaptive optics imaging system of human eye fundus, for the dynamic characteristic of human eye aberration, deformable mirror must be able to track and compensate the human eye aberration in time to achieve clear and high resolution fundus imaging. The technology of adaptive optics aberration correction control was studied, and an adaptive optics continuous system model was established according to the automatic control theory. The control system model and its control properties based on the pure integral, proportion integral, Smith precompensation were analyzed emphatically. The aberration correction experiments with dynamic aberration samples were canried out on a adaptive optics imaging system platform. And 10 human eyes were included in the experiments.Compared to the aberration ((0.862±0.088)λ, λ=0.785μm) before the correction, the aberration ( (0.154 ± 0.033) λ, (0.133 ± 0.026)λ, (0.103 ± 0.011)λ) with the pure integral control, PI control and Smith precompensation control were significantly lower (P<0.05). The above results indicated the aberration correction system with various controllers possessed a certain aberration correction capability. The ANOVA results showed that corrected aberrations with Smith precompensation control was significantly lower than the pure integral control and PI control method, which indicated that the aberration corrected with Smith precompensation controller had the maximum significant difference, that is the best effect of aberration correction. The Smith precompensation control model can provide theoretical basis for correcting human eye dynamic aberration to obtain human eye fundus image.
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