Digital holographic adaptive optics for retinal imaging without wavefront sensor

描述(申请人提供)：提出了一种新的自适应光学视网膜成像系统，该系统基于数字全息术的原理，省去了传统自适应光学系统中的波前传感器和波前调制器。数字全息术是一种新兴的成像技术，它提供了对光场相位的直接数值访问，从而实现了对光场的精确控制和操纵。在眼科成像系统中加入水解氢可以在显著降低仪器的复杂性和成本的情况下实现多种成像功能。一个典型的常规光学系统包括几个关键的硬件部件：空间光调制器、微透镜阵列和第二个用于成像的摄像机。提出的数字全息自适应光学(DAO)系统利用数字全息原理，将这些硬件部件替换为用于波前测量和像差补偿的数值处理。DAHO的波前传感和校正几乎达到了CCD相机的全分辨率。由于它不涉及反馈和迭代，而且变形测量的动态范围基本上是无限的，因此它本质上比传统的AO更快。DAO可能会提供额外的新颖成像功能，如更宽的视网膜视野、在整个弯曲视网膜表面的视场上自动对焦、视网膜表面的地形以及眼内碎片分布的3D成像。该项目将从一系列实验开始，旨在演示DAO的波前传感和像差补偿的原理，并测量和表征基本的成像参数，如分辨率、点扩展函数、光预算、信号和噪声以及动态范围。然后建造一个自给自足的台式仪器，足够紧凑和坚固，可以用真实的眼睛模型和切除的动物眼睛进行系统的成像实验。开发一套软件程序是建设的重要组成部分。将进行一系列成像实验，以评估DAO仪器的成像能力，并开发几种特殊的成像技术，特别是突出拟议系统的一些独特能力。拟议的DAO仪器将提供视网膜和其他结构的高分辨率图像以及一些新的成像功能，但与当前技术相比，其复杂性和成本要低得多。这将使高分辨率眼科成像可用并适用于眼科更广泛的诊断和治疗，如视网膜变性、青光眼和屈光手术。

DESCRIPTION (provided by applicant): A new adaptive optics (AO) retinal imaging system is proposed that is based on the principles of digital holography and dispenses with the wavefront sensor and wavefront modulator of conventional AO system. Digital holography (DH) is an emergent new imaging technology that gives direct numerical access to the phase of the optical field, thus allowing precise control and manipulation of the optical field. Incorporation of DH in an ophthalmic imaging system can lead to versatile imaging capabilities at substantially reduced complexity and cost of the instrument. A typical conventional AO system includes several critical hardware pieces: spatial light modulator, lenslet array, and a second CCD camera in addition to the camera for imaging. The proposed digital holographic adaptive optics (DHAO) system replaces these hardware components with numerical processing for wavefront measurement and compensation of aberration through the principles of digital holography. The wavefront sensing and correction by DHAO have almost the full resolution of the CCD camera. It is inherently faster than conventional AO because it does not involve feedback and iteration, and the dynamic range of deformation measurement is essentially unlimited. DHAO may offer additional novel imaging capabilities such as wider field of view of the retina, automatic focus over the entire FOV of curved retinal surface, topography of the retinal surface, and 3D imaging of intraocular debris distribution. The proposed project will start with a set of experiments designed to demonstrate the principles of wavefront sensing and aberration compensation by DHAO and to measure and characterize basic imaging parameters such as the resolution, point spread function, light budget, signal and noise, and dynamic range. Then a self- contained benchtop instrument is to be constructed, sufficiently compact and robust for systematic imaging experiments with realistic eye models and excised animal eyes. Development of a suite of software programs is an important part of the construction. A series of imaging experiments will be carried out to evaluate the imaging capabilities of the DHAO instrument and to develop several special imaging techniques, especially to highlight some of the unique capabilities of the proposed system. The proposed DHAO instrument will provide high resolution images of retina and other structures as well as a number of novel imaging capabilities, but with significantly lower complexity and cost compared to current technology. This will make high-resolution ophthalmic imaging available and applicable to a wider range of diagnosis and treatments in ophthalmology, such as in retinal degeneration, glaucoma, and refractive surgery.