■数字全息显微镜(DHM)是一种无标签的显微镜技术,通过测量透明生物样品诱导的光的光路延迟来提供时间分辨的定量相位成像(QPI)。DHM已用于各种生物医学应用,比如癌症研究和精子细胞评估,以及体外药物或毒性测试。它的无透镜版本,数字无透镜全息显微镜(DLHM),是一种新兴的技术,可以缩小尺寸,轻量级,和具有成本效益的成像系统。这些特性使DLHM适用,例如,在有限的资源实验室,偏远地区,和即时护理应用。
■除了上述优点,DLHM的在线布置还包括双图像存在的限制,这可以限制准确的QPI。因此,我们提出了一种紧凑的无透镜共路干涉离轴方法,能够对快速移动的生物标本进行定量成像,例如流动中的活细胞。
■我们建议无透镜空间复用干涉显微镜(LESSMIM)作为先前报道的空间复用干涉显微镜(SMIM)概念的无透镜变体。LESSMIM包括基于单个衍射光栅以实现数字离轴全息的公共路径干涉架构。从一系列单发离轴全息图中,双图像自由和时间分辨QPI是通过常用的基于傅立叶滤波的重建方法来实现的,像差补偿,和数值传播。
■最初,分辨率测试图和时间稳定性研究的结果通过实验证明了LESSMIM概念。然后,QPI的准确性和活贴壁细胞培养物的成像能力被表征。最后,利用微流体通道,评估流式细胞术中的悬浮细胞。
■LESSMIM克服了在线DLHM的几个限制,并在紧凑的光学布置中提供了快速的时间分辨QPI。总之,LESSMIM代表了一种有前途的技术,具有潜在的生物医学应用,可用于快速成像,例如成像流式细胞术或精子细胞分析。
UNASSIGNED: Digital holographic microscopy (DHM) is a label-free microscopy technique that provides time-resolved quantitative phase imaging (QPI) by measuring the optical path delay of light induced by transparent biological samples. DHM has been utilized for various biomedical applications, such as cancer research and sperm cell assessment, as well as for in vitro drug or toxicity testing. Its lensless version, digital lensless holographic microscopy (DLHM), is an emerging technology that offers size-reduced, lightweight, and cost-effective imaging systems. These features make DLHM applicable, for example, in limited resource laboratories, remote areas, and point-of-care applications.
UNASSIGNED: In addition to the abovementioned advantages, in-line arrangements for DLHM also include the limitation of the twin-image presence, which can restrict accurate QPI. We therefore propose a compact lensless common-path interferometric off-axis approach that is capable of quantitative imaging of fast-moving biological specimens, such as living cells in flow.
UNASSIGNED: We suggest lensless spatially multiplexed interferometric microscopy (LESSMIM) as a lens-free variant of the previously reported spatially multiplexed interferometric microscopy (SMIM) concept. LESSMIM comprises a common-path interferometric architecture that is based on a single diffraction grating to achieve digital off-axis holography. From a series of single-shot off-axis holograms, twin-image free and time-resolved QPI is achieved by commonly used methods for Fourier filtering-based reconstruction, aberration compensation, and numerical propagation.
UNASSIGNED: Initially, the LESSMIM concept is experimentally demonstrated by results from a resolution test chart and investigations on temporal stability. Then, the accuracy of QPI and capabilities for imaging of living adherent cell cultures is characterized. Finally, utilizing a microfluidic channel, the cytometry of suspended cells in flow is evaluated.
UNASSIGNED: LESSMIM overcomes several limitations of in-line DLHM and provides fast time-resolved QPI in a compact optical arrangement. In summary, LESSMIM represents a promising technique with potential biomedical applications for fast imaging such as in imaging flow cytometry or sperm cell analysis.