Research On Key Technology Of Minitype Adaptive Optics Correction System For Human Eye's Wavefront Aberration

Problems on retinal imaging of human eye are attached importance to the field of ophthalmologic video at all time, and its solution is probitious to the advanced diagnosis on the fundus ailments. Along with the successful application to the wavefront aberrations correction of the human eye, the cellular images of the fundus retina were acquired by the scholars many years later, which provided the new moment for the diagnosis on the fundus sicknesses. Technologies of MEMs (Micro Electro Mechanical system) were changing with each passing day, and modern devices being used in wavefront sensing and wavefront correction came forth incessantly. Low-cost, little-size settings of adaptive optics gradually are taken into account and investigated by the professionals in the field of ophthalmologic video. In the paper, a minitype system of adaptive optics based on the HS(Hartmann-Shack) wavefront sensor and Micromachined membrane deformable mirror was builded, and the included key technologies were analyzed and optimized in order to improve the correction capability of the whole adaptive optics equipment. The mostly content is as follows:1) The in-existence devices being used into the retinal imaging of human eye and their limitions were expatiated, and the imaging qualify of imaging devices that was increased by adaptive optics and the development level of devices and Technologies about adaptive optics were did. Finally, the status in quo of wavefront aberration correction by adaptive optics and fundus cellular observation in inner and outer nation were summarized.2) The histiocytic structures of human eye and its retina pictured, and the exit wavefront aberration was defined and the characteristics of Zernike polynomials were analyzed. With Zernike polynomials theorical modal description of wavefront aberration of human eye was put forward, then influence on the imaging qualify by Zernike modal aberration were discussed,which contents involved the relation between the MTF(Modulated Transfer Function),SR(Strehl Ratio) and the low order, high order modal aberraion.3) The types of wavefront sensor in the adaptive optics were enumerated and priciples and theotical models of HS sensor were introduced, which contents involved into location of center of mass of spot and the error of slope sensing. In the modal reconstruction of HS sensor, at first the modal based on Gram-Schimit and Householder decoupling transforming were put award, and as a result influence of decoupling modes on the modal reconstruction was discussed. Finally, a new optimal modes of slope sensing error of HS sensor was brought forward, and its advanced capacity was verified by the simulation.4) The type of wavefront correctors were introdued, and the strcuture and performance of schism actuators deformable mirrors and whole actuators mirrors were compared. The Micromachined Membrane deformable mirror and its influence function were described characteristicly, with which the modal reconstruction and correction can be achieved. In this paper two new approaches were introduced: one was principal component analysis ,and the other was simulation annealing, then their results of aberrated wavefront correction were given. Finally, the space resolution of the little-size adaptive optics was discussed5)Modularization designing of retinal microscopy based on the AO(Adaptive optics) were built, and performance parameters of its components were analyzed, then designing parameters and function configurations were created.data transfer and control communication of AO were set up among devices..6) In order to verify the performance of wavefront correction of above adaptive optics, the experimental adaptive optics setting was build. With a optical test lens and artifical simulation eye the correction capability to aberrated wavefront was validated, and final results were reported and analyzed.