Imaging of non-parabolic velocity profiles in converging flow with optical coherence tomography

Abstract

The optical coherence tomography method was explored for two-dimensional flow mapping of a highly scattering fluid in flow with complex geometry. Converging flow (capillary entry) with 4:1 constriction was used for demonstration of non-invasive and remote methods of mapping varying velocity profiles. Downstream of the geometry was scanned with approximately 10 x 10 x 10 microm3 spatial resolution and structural imaging of the lumen and images of one particular velocity were acquired. Stable concave, blunted and parabolic profiles are obtained at different distances of the inlet length. Application of the technique for the blood circulation is also discussed.

Optical coherence tomography imaging depth enhancement by superficial skin optical clearing

“…Signal processing has been performed digitally offline with a standard demodulation algorithm developed earlier [26][27][28]. The algorithm utilizes short-time Fourier transform (STFT) with the sliding Hanning window.…”

Turbulence monitoring with Doppler Optical Coherence Tomography

“…In the current Letters we present the results of monitoring of turbulent flow in T-and Y-shaped micro vessel junctions with DOCT, a logical extension of an earlier study [3]. The results of this study are highly important in rheology and cardiology to better understand the effect of blood flow on the rupture potential of atherosclerotic plaques [4].…”

Optical Coherence-domain Imaging of Subcutaneous Human Blood Vessels in vivo

“…The images have been taken close to a Y-junction of blood vessels considering possibility of further investigation of blood flow with complex geometry [16][17][18] in vivo.…”

“…In addition, all experiments have been performed when incident light was perpendicular to the surface of the skin. Will it be possible to extract valuable velocity information in such transitional coherence-gated mode to study flows with complex geometry [16][17][18] in human subcutaneous junction of blood vessels is still a question to solve. Applying optical circulator (Faraday rotator) instead of the first 1x2 fibre splitter it is possible additionally reduce the source power by the factor of two and eliminate the signal reflected back into the source [15].…”

“…Signal processing has been performed digitally offline with a standard demodulation algorithm, which was applied earlier [9,16]. This algorithm utilises short-time Fourier transform (STFT) with the sliding Hanning window.…”