IDBR: Bridging Electronic Focus and Aberration Control for Scanning Laser Microscopes from Lab to Commercial Readiness

蒙大拿州立大学的David Dickensheets博士获得了一项资助，用于开发一种新的生物显微镜电子聚焦和像差控制仪器，特别适用于厚活组织或完整动物的显微镜。作为研究自然状态下的生命系统的关键工具，活体和完整组织的高分辨率显微镜仍然是一个巨大的挑战。该项目解决了活体显微镜的主要技术障碍：通过厚的、未准备的标本成像时控制焦点和管理像差。目前大多数用于生命显微镜的仪器都是以某种方式机械固定标本，然后将显微镜物镜内移或外移以调整焦距。基于可变形MEMS反射镜（MEMS是微机电系统的首字母缩写）开发了一种系统，该系统可以在保持物镜在固定位置的同时调节光束焦点在样品中的位置。没有任何透镜或样品的机械平移，因此没有振动。镜面形状的精确控制消除了每个深度的球面像差。快速响应时间允许聚焦步进或扫描，并且当与侧束扫描同步时，允许沿任何斜面甚至沿弯曲表面（如细胞膜）对3D样品进行切片。没有竞争技术提供MEMS可变形镜技术所提供的精度，速度和潜在的低成本。在我们的实验室中演示了利用MEMS变形镜进行电子聚焦和像差控制的基本技术。该项目的目的是弥合我们的第一个原型演示和准备商业化和广泛分发的仪器之间的差距。当完全开发时，该技术将把任何激光扫描共聚焦或双光子/多光子显微镜变成电子控制的三维成像仪器，能够进行x-y， x-z或任意轨迹扫描。随着所提出的仪器和未来软件的发展，许多复杂的图像采集方案将成为可能，包括多平面成像、高NA下增强聚焦深度、图像特征跟踪和稳定。这项新技术的潜在应用范围非常广泛。开发中的第一个模块是用于扫描激光显微镜，但未来的应用包括用于宽视场白光和荧光显微镜的快速、无像差电子对焦控制，以及用于腹腔镜、内窥镜或导管平台的小型化体内显微镜，这些显微镜目前在原位调节焦点的能力非常有限。可变形反射镜的进展将对天文学、摄影和光数据存储的应用产生兴趣。除了其科学影响外，该项目还包括研究和教育的整合，培养了一名女工程博士生，并为几名工程本科生提供研究经验，这些本科生将在审查技术时直接与生物学研究人员一起参与跨学科活动。该项目还将参与为蒙大拿部落学院的学生和教师设立的暑期实习计划。

A grant has been awarded to Dr. David Dickensheets at Montana State University to develop a new instrument for electronic focus and aberration control in biological microscopy, with particular application to microscopy of thick living tissues or intact animals. A critical tool for studying living systems in their natural state, high-resolution microscopy of living and intact tissues remains a tremendous challenge. This project addresses a major technological barrier for in vivo microscopy: controlling the focus and managing aberrations when imaging through thick, unprepared specimens. Most current instruments for vital microscopy rely on mechanically fixing the specimen in some manner and then translating the microscope objective lens in or out to adjust focus. A system has been developed based on a deformable MEMS mirror (MEMS is an acronym for micro-electromechanical systems) that adjusts the location of the beam focus in the sample while maintaining the objective lens in a fixed position. There is no mechanical translation of any lenses or of the sample, and therefore no vibration. Precise control of the mirror shape eliminates spherical aberration at every depth. Fast response time allows focus stepping or scanning, and when synchronized with lateral beam scanning allows sectioning of 3D samples along any oblique plane or even along convoluted surfaces such as a cell membrane. No competing technology offers the precision, speed and potential low cost afforded by MEMS deformable mirror technology. The underlying technology of electronic focus and aberration control using a MEMS deformable mirror has been demonstrated in our laboratory. The aim in this project is to bridge the gap between our first prototype demonstration and an instrument ready for commercialization and broad distribution. When fully developed, this technology will turn any laser scanning confocal or two-photon/multi-photon microscope into an electronically controlled 3D imaging instrument, capable of x-y, x-z or arbitrary trajectory scanning. With the proposed instrument and future software development, many sophisticated image acquisition schemes would become possible including multi-plane imaging, enhanced depth of focus at high NA, and image feature tracking and stabilization.The scope of potential use for this new technology is extremely broad. The first module in development is for scanning laser microscopes, but future applications include fast, aberration-free electronic focus control for wide-field white light and fluorescence microscopes and miniaturized in-vivo microscopes designed for laparoscope, endoscope or catheter platforms that presently have extremely limited ability to adjust focus in situ. Advances made with the deformable mirrors will be of interest for applications in astronomy, photography and optical data storage. In addition to its scientific impact the project embraces integration of research and education, training one female engineering Ph.D. student and providing research experience for several undergraduate engineering students, who will participate directly in cross-disciplinary activities with biology researchers as they vet the technology. This project will also participate in an established summer internship program for students and faculty from tribal colleges in Montana.