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

蒙大拿州立大学的大卫迪肯斯博士获得了一笔赠款，用于开发一种新的仪器，用于生物显微镜的电子聚焦和像差控制，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生命系统的重要工具，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。该项目解决了体内显微镜的一个主要技术障碍：通过厚的，未准备好的标本成像时，控制焦点和管理像差。目前大多数用于活体显微镜检查的仪器都依赖于以某种方式机械地固定样本，然后将显微镜物镜透镜平移进或平移出以调节焦点。已经开发了一种基于可变形MEMS镜（MEMS是微机电系统的首字母缩略词）的系统，该系统调节样品中的光束焦点的位置，同时将物镜透镜保持在固定位置。没有任何镜片或样品的机械平移，因此没有振动。对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，并且当与横向光束扫描同步时，允许沿沿着任何倾斜平面或甚至沿着回旋表面（诸如细胞膜）对3D样品进行切片。没有任何竞争技术能够提供MEMS可变形反射镜技术所提供的精度、速度和潜在的低成本。在我们的实验室中已经展示了使用MEMS可变形反射镜的电子聚焦和像差控制的基础技术。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销售的仪器之间的差距。当这项技术得到充分发展时，它将把任何激光扫描共聚焦或双光子/多光子显微镜变成一个电子控制的3D成像仪器，能够进行x-y，x-z或任意轨迹扫描。随着仪器的发展和软件的开发，许多复杂的图像采集方案将成为可能，包括多平面成像，在高NA下增强焦深，以及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色光和荧光显微镜的快速、无像差的电子聚焦控制，以及为腹腔镜、内窥镜或导管平台设计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。变形镜的发展将在天文学、摄影学和光学数据存储等领域得到广泛的应用。除了其科学影响外，该项目还包括研究和教育的一体化，培养了一名女工程博士。学生，并提供研究经验，为几个本科工程专业的学生，谁将直接参与跨学科活动与生物研究人员，因为他们审查的技术。该项目还将参加为蒙大拿州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.