Phase-resolved optical coherence tomography and optical Doppler tomographyfor imaging blood flow in human skin with fast scanning speed and high velocity sensitivity

We have developed a novel phase-resolved optical coherence tomography (OCT) and optical Doppler tomography (ODT) system that uses phase information de rived from a Hilbert transformation to image blood flow in human skin with fast scanning speed and high velocity sensitivity. Using the phase change b etween sequential scans to construct flow-velocity imaging, this technique decouples spatial resolution and velocity sensitivity in flow images and in creases imaging speed by more than 2 orders of magnitude without compromisi ng spatial resolution or velocity sensitivity. The minimum flow velocity th at can be detected with an axial-line scanning speed of 400 Hz and an avera ge phase change over eight sequential scans is as low as 10 mu m/s, while a spatial resolution of 10 mu m is maintained. Using this technique, we pres ent what are to our knowledge the first phase-resolved OCT/ODT images of bl ood flow in human shin. (C) 2000 Optical Society of America OCIS codes: 110 .4500, 170.3880, 100.5070.