激光扫描共聚焦显微镜弱荧光成像控制方法研究

Research on control method of weak fluorescence imaging in laser scanning confocal microscopy

目的:激光扫描共聚焦显微镜(共聚焦显微镜)在医学检测弱荧光图像中存在对焦耗时长、检流式扫描仪速度慢、容易受负载扰动和电机参数改变影响等诸多问题,而弱荧光图像具有高分辨率、大视野的成像要求。方法:提出了模糊控制自适应整定的PID调整方法,搭建了相应的激光扫描共聚焦显微镜控制系统;并在给定步进输入和动态变化的阶梯输入下对现有PID和自适应模糊PID控制方法进行了仿真实验。结果:相较于PID控制,模糊PID控制的稳态误差明显减小,超调量低于10%,大大提高了运动平台的稳定性,且调节XY载物平台至稳定所需的调节时间更短。结论:将自适应模糊PID控制策略应用于共聚焦显微镜XY控制平台,具有动态响应快、抗干扰性强、稳定性好的特点,在一定程度上满足了弱荧光图像高分辨率、大视野的成像要求。

Objective:Laser confocal scanning microscopy has the problems of long focusing time,slow galvanometer speed and easy to be affected by load disturbance and motor parameter change in the process of detecting weak fluorescence images,which demands high resolution and a large field of view. Method: In this paper,we proposed the PID adjustment method of fuzzy control adaptive tuning. The corresponding laser confocal scanning microscope control system was built. And a simulation experiment was carried out about the existing PID and adaptive fuzzy PID control method. Result: Compared with the PID control,the steady-state error of the fuzzy PID control is significantly reduced,and the overshoot is less than 10%,which greatly improves the stability of the motion platform. Moreover,the time required to adjust the XY platform to stability is shorter. Conclusion: The adaptive fuzzy PID control strategy is applied to the XY control platform of confocal microscope. It has the characteristics of fast dynamic response,strong anti-interference and good stability,which satisfies the imaging requirements of high-resolution and large-field of weak fluorescence images to a certain extent.