Two-dimensional estimation technique for doppler optical coherence tomography (OCT)

US7894046B2 · kind B2 · utility

Inventors

• Darren Ross Morofke · Toronto, CA
• Victor Xiao Dong Tang · Toronto, CA
• Michael Kolios · Hamilton, CA

Key dates

• Filing date: Jan 7, 2009
• Grant date: Feb 22, 2011
• Expiry date: Aug 20, 2029

Classification

• Technology area (CPC G): Physics
• CPC primary: G01P5/22
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Optical Coherence Tomography (OCT) is a high-resolution, non-invasive technique to image subsurface tissue and tissue functions. A broadband light source illuminates an object and the reflected photons are processed using an interferometer, demodulated into inphase and quadrature components and then digitized. The captured data contains information about the velocity of the moving scatterers but current Doppler estimation algorithms have a limited velocity detection range. Using a two dimensional velocity estimation, Doppler OCT (DOCT) can be used for the detection of in vivo aortic blood flow rates of over 1 m/s peak velocity through an esophageal DOCT probe. Previous methods have used a transverse Kasai (TK) autocorrelation estimation to estimate the velocity which is good for slow velocities, such as in the microvasculature. By calculating the Kasai autocorrelation with a lag in the depth or axial direction, backscattered frequency information is obtained which yields high velocity rate information. Through subtraction with stationary backscattered information, the Doppler shift is obtained by the axial Kasai (AK) technique. Through utilizing information from two dimensions, vel…