Digital holographic adaptive optics for retinal imaging without wavefront sensor

描述（申请人提供）：提出了一种基于数字全息原理的新型自适应光学（AO）视网膜成像系统，该系统省去了传统AO系统的波前传感器和波前调制器。数字全息术（DH）是一种新兴的成像技术，它可以直接对光场的相位进行数值访问，从而实现对光场的精确控制和操纵。在眼科成像系统中加入DH可以在大大降低仪器复杂性和成本的情况下实现多功能成像能力。一个典型的传统AO系统包括几个关键的硬件部分：空间光调制器、透镜阵列和除了用于成像的相机之外的第二个CCD相机。本文提出的数字全息自适应光学（DHAO）系统利用数字全息原理，用数字处理技术代替这些硬件器件，实现波前测量和像差补偿。DHAO的波前传感和校正几乎达到CCD相机的全分辨率。它本质上比传统的AO更快，因为它不涉及反馈和迭代，并且变形测量的动态范围本质上是无限的。DHAO可以提供额外的新成像功能，如更宽的视网膜视野，在弯曲的视网膜表面的整个视场上自动聚焦，视网膜表面的地形，以及眼内碎片分布的3D成像。本项目将从一系列实验开始，旨在展示DHAO的波前传感和像差补偿原理，并测量和表征基本成像参数，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，一个独立的台式仪器将被构建，足够紧凑和坚固的系统成像实验与真实的眼睛模型和切除的动物眼睛。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DHAO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。所提出的DHAO仪器将提供视网膜和其他结构的高分辨率图像以及许多新颖的成像能力，但与现有技术相比，其复杂性和成本显着降低。这将使高分辨率眼科成像成为可能，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.