Red blood cells have intrinsic transient absorption property at the near-infrared region, allowing for label-free detection and imaging. We present a new approach to measure the blood flow velocity in vivo with a transient absorption microscope and correlation analyses of signal sequences. With specific scan modes, we have quantitatively obtained the flow velocity in capillaries, arteries, and veins in a live zebrafish with accuracy of about 30 μm/s. In addition, a high-resolution three-dimensional vessel network can be reconstructed through this approach with spatial resolution of 1 μm.

中文翻译：

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用于体内红细胞流速测量的无标记瞬态吸收显微镜

红细胞在近红外区域具有固有的瞬态吸收特性，可进行无标记的检测和成像。我们提出了一种新的方法，用瞬态吸收显微镜和信号序列的相关分析来测量体内的血流速度。通过特定的扫描模式，我们定量地获得了活斑马鱼中毛细血管，动脉和静脉中的流速，其准确度约为30μm/ s。此外，可以通过这种方法以1μm的空间分辨率重建高分辨率的三维血管网络。