Wei Franklin, Hagan Kristen, Viehland Christian, Tao Yuankai K, Kuo Anthony N, Izatt Joseph A, Dhalla Al-Hafeez
Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA.
Biomed Opt Express. 2023 Sep 11;14(10):5162-5181. doi: 10.1364/BOE.500608. eCollection 2023 Oct 1.
High-speed, accessible, and robust imaging of the human retina is critical for screening of retinal pathologies, such as diabetic retinopathy, age-related macular degeneration, and others. Scanning light ophthalmoscopy (SLO) is a retinal imaging modality that produces digital, images of the human retina with superior image gradability rates when compared to the current standard of care in screening for these diseases, namely the flood-illumination handheld fundus camera (HFC). However, current-generation commercial SLO systems are mostly tabletop devices, limiting their accessibility and utility in screening applications. Moreover, most existing SLO systems use raster scan patterns, which are both inefficient and lead to undesired subject gaze drift when used with visible or pseudo-visible illumination. Non-raster scan patterns, especially spiral scanning as described herein, promise advantages in both scan efficiency and reduced subject eye motion. In this work, we introduce a novel "hybrid spiral" scan pattern and the associated hardware design and real-time image reconstruction techniques necessary for its implementation in an SLO system. Building upon this core hybrid spiral scanning SLO (HSS-SLO) technology, we go on to present a complete handheld HSS-SLO system, featuring a fiber-coupled portable patient interface which leverages a dual-clad fiber (DCF) to form a single-path optical topology, thus ensuring mechanically robust co-alignment of illumination and collection apertures, a necessity for a handheld system. The feasibility of HSS-SLO for handheld, imaging is demonstrated by imaging eight human volunteers.
对人类视网膜进行高速、可及且稳健的成像对于筛查视网膜病变至关重要，这些病变包括糖尿病性视网膜病变、年龄相关性黄斑变性等。扫描激光检眼镜（SLO）是一种视网膜成像方式，与目前用于筛查这些疾病的标准设备即泛光照明手持式眼底相机（HFC）相比，它能生成具有卓越图像可分级性的人类视网膜数字图像。然而，当前一代的商用SLO系统大多是台式设备，这限制了它们在筛查应用中的可及性和实用性。此外，大多数现有的SLO系统使用光栅扫描模式，这种模式效率低下，并且在与可见光或准可见光照明一起使用时会导致受试者注视漂移。非光栅扫描模式，尤其是本文所述的螺旋扫描，在扫描效率和减少受试者眼睛运动方面都有优势。在这项工作中，我们介绍了一种新颖的“混合螺旋”扫描模式以及相关的硬件设计和实时图像重建技术，这些技术是在SLO系统中实现该模式所必需的。基于这种核心的混合螺旋扫描SLO（HSS - SLO）技术，我们进而展示了一个完整的手持式HSS - SLO系统，其特点是具有光纤耦合的便携式患者接口，该接口利用双包层光纤（DCF）形成单路径光学拓扑结构，从而确保照明和采集孔径在机械上的稳健共对准，这对于手持式系统来说是必要的。通过对八名人类志愿者进行成像，证明了HSS - SLO用于手持式成像的可行性。
