We report wide-field polygon-scanning functional OR-PAM that for the first time achieves 1-MHz A-line rate of oxygen saturation in vivo. We address two technical challenges. The first is a 1-MHz dual-wavelength pulsed laser that has sufficient pulse energy and ultrafast wavelength switching. The second is a polygon-scanning imaging probe that has a fast scanning speed, a large field of view, and great sensitivity. The OR-PAM system offers a B-scan rate of 477.5 Hz in a 12-mm range and a volumetric imaging rate of ∼1 Hz over a 12 × 5 mm² scanning area. We image microvasculature and blood oxygen saturation in a 12 × 12 mm² scanning area in 5 s. Dynamic imaging of oxygen saturation in the mouse ear is demonstrated to monitor fast response to epinephrine injection. The new wide-field fast functional imaging ability broadens the biomedical application of OR-PAM.

我们报告了宽视场多边形扫描功能 OR-PAM，首次实现了体内氧饱和度的 1 MHz A 线速率。我们解决了两个技术挑战。第一个是 1 MHz 双波长脉冲激光器，具有足够的脉冲能量和超快的波长切换。二是多边形扫描成像探头，扫描速度快、视场大、灵敏度高。 OR-PAM 系统在 12 毫米范围内提供 477.5 Hz 的 B 扫描速率，在 12 × 5 mm ²扫描区域内提供 ~1 Hz 的体积成像速率。我们在 5 秒内对 12 × 12 mm ²扫描区域中的微血管和血氧饱和度进行成像。小鼠耳内氧饱和度的动态成像被证明可以监测肾上腺素注射的快速反应。新的广域快速功能成像能力拓宽了 OR-PAM 的生物医学应用。