Interferometric detection of 3D motion using computational subapertures in optical coherence tomography.

Area of Science:

• Biomedical Optics
• Medical Imaging
• Optical Coherence Tomography

Background:

• Doppler optical coherence tomography (OCT) excels at quantifying axial motion but struggles with lateral motion detection.
• Existing methods for full 3D motion quantification, like three-beam Doppler OCT, require significant experimental complexity.

Purpose of the Study:

• To present a novel computational approach for determining all three components of the motion vector using phase-stable complex-valued OCT datasets.
• To overcome the experimental limitations of previous 3D Doppler OCT techniques.

Main Methods:

• Utilized full-field swept-source OCT to acquire phase-stable complex-valued datasets.
• Applied Fourier domain filtering to computationally isolate subapertures for analysis.
• Calculated the 3D motion vector components with interferometric precision.

Main Results:

• The computational method successfully quantifies micro-rotation in a scattering sample.
• Achieved accuracy in motion vector component calculation exceeds imaging resolution by orders of magnitude in all dimensions.
• Demonstrated feasibility by recording the 3D motion vector field in ex-vivo porcine retina during laser photocoagulation.

Conclusions:

• The presented numerical analogue to three-beam Doppler OCT enables precise, high-accuracy 3D motion vector quantification.
• This computational approach offers a less experimentally demanding alternative for advanced motion analysis in OCT.
• Potential applications include detailed investigation of dynamic processes in biological tissues.