Research on the Accuracy Detection Methord of Excimer Laser Corneal Therapeutic Machine’s Alignment System Based on Ellipse Fitting Algorithm

Accurate alignment of the optical center of the eye is the key to ensure that no eccentric cutting occurs in refractive surgery. In order to detect the accuracy of the alignment system of the excimer laser corneal ametropia cure system, a least-squares ellipse fitting detection method based on the detection plate is proposed. Firstly, a detection plate with simulated pupil pattern and scale line is designed, and then the cutting pattern and simulated pupil pattern are preprocessed by binarization, threshold segmentation technology, edge detection and other methods.Finally, the least squares ellipse fitting method is used to detect the deviation degree of the center of the cutting pattern and the simulated pupil pattern in the X-axis and Y-axis directions, so as to measure the accuracy of the alignment system. Experiments show that the detection method can be carried out in the surgical mode, and the alignment deviation of the machine can be accurately calculated compared with the manual reading.