Flow Measurement by Lateral Resonant Doppler Optical Coherence Tomography in the Spectral Domain

Abstract

Abstract:In spectral domain optical coherence tomography (SD-OCT), any transverse motion component of a detected obliquely moving sample results in a nonlinear relationship between the Doppler phase shift and the axial sample velocity restricting phase-resolved Doppler OCT (PR-DOCT). The size of the deviation from the linear relation depends on the amount of the transverse velocity component, given by the Doppler angle, and the height of the absolute sample velocity. Especially for very small Doppler angles between the horizontal and flow direction, and high flow velocities, the detected Doppler phase shift approaches a limiting value, making an unambiguous measurement of the axial sample velocity by PR-DOCT impossible. To circumvent this limitation, we propose a new method for resonant Doppler flow quantification in spectral domain OCT, where the scanner movement velocity is matched with the transverse velocity component of the sample motion similar to a tracking shot, where the camera is moved with respect to the sample. Consequently, the influence of the transverse velocity component of the tracked moving particles on the Doppler phase shift is negligible and the linear relation between the phase shift and the axial velocity component can be considered for flow velocity calculations. The proposed method is verified using flow phantoms on the basis of 1% Intralipid solution and diluted human blood.

Optical coherence tomography velocimetry based on decorrelation estimation of phasor pair ratios (DEPPAIR)

“…Depending on the chosen method they can be applied to the amplitude, phase or the complex signal of OCT. The equivalence of the average estimation of some of those algorithms has been addressed in previous reports [15,17] but to our knowledge a quantitative comparison of the retrieved information content has been missing, so far. Additionally, some of those algorithms rely on the use of specific scan patterns, such as M-scans which require all measurements to be part of a trace with equidistant time intervals between individual measurements.…”

“…The earliest implementation, Doppler OCT [9][10][11], measured the average frequency shift within A-scans. Significant work has been done to improve flow sensitivity by comparing adjacent A-scans [12] describe noise influences [13][14][15] and optimize estimation precision and accuracy [16][17][18][19][20]. However, Doppler-OCT reveals only information about the axial velocity component.…”

Scanning dynamic light scattering optical coherence tomography for measurement of high omnidirectional flow velocities

“…Flow measurements with OCT have been performed using phase-resolved Doppler OCT, lateral resonant Doppler OCT [2], and M-scan correlation-based DLS-OCT [3][4][5]. The axial velocity of Doppler OCT is limited by phase wrapping.…”

Decomposition of Multicomponent Micro-Doppler Signals Based on HHT-AMD

“…Micro-motion and micro-Doppler phenomena can be observed everywhere in our lives and contribute to the fields of radar-based exploration and surveillance of humanity activities [8]. Its underlying civilian and military applications include security monitoring, urban warfare, law enforcement, healthcare, kinematics, search/rescue, anti-terrorism surveillance, and so on [9,10].…”