High-speed CCD intravital microscope-visualization of subendocardial arteriolar blood velocity

To visualize the subendocardial arteriolar blood velocity, the authors developed a high-speed CCD microscope. The vascular images focused on the special CCD through a needle-probe were stored on a digital memory every 5 ms (200 images/s). The size of the visual field is 1×0.8 mm², and the spatial resolution is less than 4 μm. The blood flow velocities in the microvessels were visualized by optically shinning microspheres (MS). MS (5-15 μm φ) were prepared by polymerization of styrene monomer in which fine particles of heavy elements (0.2 μmφ) were homogeneously distributed. Velocities of MS in the subendocardial arteriole were calculated by the distance of MS movement of 5 ms. The blood velocity waveforms in the microvessels were successfully obtained by the high-speed system. In conclusion, a newly developed microscope system was found to be a powerful tool for observation of dynamic blood velocity with diameter change in subendocardial microvessels in a beating dog heart