Fluid-flow velocity measurement with Doppler optical coherence tomography

Combining features of optical coherence tomography and Doppler flowmetry, Doppler optical coherence tomography (DOCT) gives a possibility of noninvasive assessment of turbid highly scattering media with a high space and velocity resolution. This and the relative simplicity of the hardware lend to DOCT clinical and biomedical importance in investigating, e.g., the blood microcirculation. Using the developed apparatus based on a fiber-optic Michelson interferometer and a superluminescent diode, experiments on the determination of the velocity of the Intralipid flow in turbid (silicone) tubes are carried out. In the paper, the apparatus is described in some detail. The feasibility of the measurements is demonstrated. It is shown that the measured Doppler shift is proportional to the infusion rate and the experimental velocity profile in the conduit is parabolic as expected for the laminar flow.