Advanced Biophotonic Structured Illumination Imaging System Design

“该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。“0933059 IzattStructured illumination（SI）是新一代的技术之一，最近被证明可以突破显微镜的衍射极限。超分辨率的SI方法涉及用空间频率载波照射物体，该空间频率载波将物体的高频特征下移到成像系统的光学传递函数内。对于线性响应于入射照明的物体，分辨率增加2倍是可能的，而对于非线性响应的物体（例如荧光或受激发射的饱和），分辨率提高理论上是无限的（尽管它与灵敏度相权衡）。应用这种方法作为对标准桌面显微镜的修改，已经报道了具有50 nm分辨率的超分辨率成像。SI成像的先前实现方式已经利用了简单的正弦照明图案，并且依赖于确定性相移和在不同角度取向处的多次曝光来获取超分辨图像重建所需的完整复k空间数据。这些方法在实验室条件下，这些参数是可控的稳定和良好的特征显微镜是实用的。SI成像的原理代表了成像科学的根本进步，并且在各种生物光子成像应用（包括人类临床诊断）中具有分辨率改进的潜力。SI成像的优点在待成像的物体或成像装置本身的特定特征限制数值孔径并因此限制可实现的分辨率的情况下特别引人注目。前者的一个例子是在人类视网膜的成像中，其中解剖学虹膜和中心区域外部的角膜的光学质量限制了可用的数值孔径。后者的一个例子是在内窥镜或导管成像中，其中光学器件的物理尺寸与所需的工作距离相结合，严重限制了数值孔径。建议的项目将启动一项研究计划，研究如何扩展SI成像技术，以满足临床光学仪器所需的鲁棒性和速度要求。该项目将专注于在活体人眼中对人类视网膜进行超分辨成像的目标，研究人员在光学相干断层扫描技术的开发方面具有相当丰富的经验。在开发临床使用的结构照明检眼镜的标题下，首先提出实现和测试原型结构照明线扫描激光检眼镜设计。然后，将对SI技术的三个具体进展进行研究，这些进展是由从实验室过渡到临床超分辨率成像的预期困难引起的。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."0933059IzattStructured illumination (SI) is one of a new generation of techniques which have recently been demonstrated to break the diffraction limit in microscopy. The SI approach to superresolution involves illuminating the object with a spatial frequency carrier which down-shifts the object's high-frequency features to within the optical transfer function of the imaging system. For objects which respond linearly to the incident illumination, a resolution increase of 2x is possible, whereas for objects which respond nonlinearly (such as saturation of fluorescence or of stimulated emission), the resolution improvement is theoretically unlimited (although it trades off with sensitivity). Applying this methodology as a modification to standard tabletop microscopes, super-resolution imaging with 50nm resolution has been reported. Previous implementations of SI imaging have utilized straightforward sinusoidal illumination patterns, and relied upon deterministic phase shifting and multiple exposures at different angular orientations to acquire the full complex k-space data required for superresolved image reconstruction. These approaches are practical in stable and well-characterized microscopes under laboratory conditions, for which these parameters are controllable. The principles of SI imaging represent a fundamental advance in imaging science, and carry the potential of resolution improvement in a variety of biophotonic imaging applications, including human clinical diagnostics. The advantages of SI imaging are particularly compelling in situations where specific features of either the object to be imaged or of the imaging device itself limit the numerical aperture and therefore the achievable resolution. An example of the former is in imaging of the human retina, where the anatomical iris and the optical quality of the ornea outside of the central zone limit the usable numerical aperture. An example of the latter is in endoscopic or catheter imaging, where the physical size of the optics in combination with the desired working distance conspire to severely limit numerical aperture. The proposed project will initiate a research program to investigate how SI imaging technology can be extended to meet the requirements of robustness and speed required of clinical optical instrumentation. The project will focus on the goal of super-resolved imaging of the human retina in the living human eye, where the investigators have considerable previous experience in the development of optical coherence tomography technology. Under the rubric of developing a structured illumination ophthalmoscope for clinical use, it is first proposed to implement and test a prototype structured illumination line-scanning laser ophthalmolscope design. Then, research will be conducted on the development of three specific advances in SI technology motivated by anticipated difficulties in transitioning from laboratory to clinical superresolution imaging.