Vector flow velocity measurement based on bidirectional scanning in optical coherence tomography.

Area of Science:

• Biomedical Optics
• Fluid Dynamics
• Medical Imaging

Background:

• Accurate measurement of fluid flow velocity is crucial in various biomedical applications, including cardiovascular research.
• Traditional methods for flow velocity measurement using optical coherence tomography (OCT) often face limitations in capturing complex flow patterns or require system modifications.

Purpose of the Study:

• To develop and validate a novel OCT-based method for measuring vector flow velocity in complex flow fields.
• To assess the capability of the proposed method for both in vitro and in vivo applications.

Main Methods:

• The proposed method utilizes bidirectional scanning in OCT, combining dynamic light scattering OCT (DLS-OCT) for transverse velocity and Doppler OCT (DOCT) for axial velocity.
• Measurements were performed under four introduced transverse synthetic speeds to determine transverse velocity components.
• The technique was applied to measure flow fields in straight channels, an improperly welded Y-junction, and in vivo in a rabbit.

Main Results:

• The study successfully measured vector flow velocities in both simple and complex geometries, including a Y-junction.
• In vivo measurements in a rabbit demonstrated the method's applicability to biological systems.
• The proposed technique achieved accurate vector velocity measurements without requiring system modifications or extensive calibration.

Conclusions:

• The developed bidirectional scanning OCT method provides a robust and versatile approach for measuring vector flow velocity.
• This technique offers significant advantages for characterizing complex flow fields in diverse research and clinical settings.
• The ability to perform measurements without system modification makes it a practical tool for advanced flow analysis.