Dual-Detection of Phase for Full Range Doppler OCT

Dual-detection OCT offers full-range, high-sensitivity imaging for biological tissues, overcoming limitations of conventional OCT methods

 

Institute Reference: 2-11150-10011

Background

Optical Coherence Tomography (OCT) is a non-invasive imaging technology widely used in biological research and medical diagnostics. OCT captures detailed cross-sectional images of tissue structures by measuring the interference of reflected light. However, conventional OCT systems often suffer from imaging artifacts, limited depth range, and sensitivity issues, particularly when phase shifts or Doppler data are used for measuring blood flow. This new system improves upon existing OCT methods by introducing dual-detection and frequency domain methods, increasing sensitivity, resolution, and speed.

Technology Overview

The dual-detection frequency domain OCT (DD-FD-OCT) system leverages a combination of free-space and fiber-optic interferometry to improve imaging depth and eliminate mirror artifacts often introduced by Fourier-based reconstruction. A key feature of this design is the use of a non-polarizing beam splitter, which intentionally misaligns the sample and reference beams, creating a stable π/2 phase shift between them. This phase shift allows the system to simultaneously capture both the real and imaginary components of the signal, resulting in more precise and accurate structural imaging.

Beyond structural mapping, the system supports Doppler OCT, enabling detailed measurement of blood flow velocity. Additionally, it incorporates polarization-sensitive OCT (PS-OCT) capabilities, which unlock new opportunities for functional imaging by detecting tissue birefringence and polarization changes.

The apparatus integrates several advanced components to achieve these capabilities. A Fourier-Domain Mode-Locked (FDML) laser provides customizable wavelengths—ranging from approximately 800 nm to 1300 nm—depending on the imaging needs. Dual detectors work in tandem to capture phase-shifted interferometric signals, ensuring robust and reliable image acquisition. The system also performs real-time Fourier transformations, generating high-quality depth profiles without compromising speed or resolution, making it ideal for both clinical and research applications.

Benefits

The DD-FD-OCT system offers artifact-free imaging by eliminating mirror artifacts from Fourier transformations, ensuring cleaner images. Its high sensitivity enhances the signal-to-noise ratio for clearer visualization. With real-time Doppler imaging, it accurately tracks blood flow without phase wrapping issues. The system’s full-range imaging leverages the zero-path delay region for better sensitivity at deeper tissue levels. Compatible with endoscopes and handheld probes, it is well-suited for various clinical and research applications.

Applications

The DD-FD-OCT system can revolutionize multiple fields. In ophthalmology, it can provide real-time monitoring of retinal blood flow, aiding in the management of disease progression. In cardiology, it can support intravascular imaging for plaque detection and vessel health assessment. Oncology can benefit from its ability to detect microvascular changes, enhancing early tumor diagnosis. Dermatology can use its high-resolution imaging to examine skin layers for cancer screening or cosmetic treatments. Additionally, the system can advance biomedical research by enabling detailed studies of blood flow and structural changes in animal models.

URV Reference Number: 2-11150-10011
Patent Information:
Title Country Patent No. Issued Date
Optical Coherence Tomography Apparatus and Methods United States 8,363,225 1/29/2013
Category(s):
Diagnostic
Optics
For Information, Contact:
Curtis Broadbent
Licensing Manager
University of Rochester
585.273.3250
curtis.broadbent@rochester.edu
Inventors:
Kye-Sung Lee
Panomsak Meemon
Jannick Rolland-Thompson
Keywords: