人眼眼底成像系统中自适应光学像差校正控制模型研究

对于自适应光学人眼眼底成像系统，由于人眼波前像差具有动态特性，为获得清晰、高分辨率的眼底图像，变形镜必须能够实时跟踪并补偿人眼中随时间变化的像差信息。本研究探讨自适应光学像差校正控制技术，基于自动控制理论建立自适应光学连续系统模型，分析基于纯积分、比例 积分和Smith预补偿控制器下的控制系统模型及其控制性能。在自行构建的成像系统自适应光学平台上，对10只受试人眼动态像差样本进行像差校正实验。与校正前的像差（（0.862±0.088）λ，λ为0.785 μm）比较，纯积分控制、PI控制和Smith预补偿控制这3种方法的校正后像差（（0.154±0.033）λ、（0.133±0.026）λ、（0.103±0.011）λ）均显著降低（P<0.05），表明各种控制器的像差校正系统均具备一定的像差校正能力。单因素方差分析的结果表明，Smith预补偿控制的校正后像差显著低于纯积分控制和PI控制方法，表明Smith预补偿控制器下校正后的像差具有最大的显著差异，即具有最好的像差校正效果。Smith预补偿控制模型可为实时校正人眼动态像差进而获取人眼眼底图像提供理论依据。

Aberration Correction Control Model of Adaptive Optics in the Fundus Imaging System

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 pre compensation 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 pre compensation 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 pre compensation control was significantly lower than the pure integral control and PI control method, which indicated that the aberration corrected with Smith pre compensation controller had the maximum significant difference, that is the best effect of aberration correction. The Smith pre compensation control model can provide theoretical basis for correcting human eye dynamic aberration to obtain human eye fundus image.