Active-passive path-length encoded (APPLE) Doppler OCT

Abstract

We present a novel active-passive path-length encoded (APPLE) swept source Doppler optical coherence tomography (DOCT) approach, enabling three-dimensional velocity vector reconstruction of moving particles without prior knowledge of the orientation of motion. The developed APPLE DOCT setup allows for non-invasive blood flow measurements and was primarily designed for quantitative human ocular blood flow investigations. The system's performance was demonstrated by flow phantom as well as retinal vessel bifurcation measurements. Furthermore, total retinal blood flow - a biomarker aiding in diagnosis and monitoring of major ocular diseases such as glaucoma, diabetic retinopathy or central/branch retinal vein occlusion - was determined in the eyes of healthy human volunteers.

Probing dynamic processes in the eye at multiple spatial and temporal scales with multimodal full field OCT

“…4(c)), where both speed and diameter are in agreement with previous experimental findings in the literature, which used slit-lamp microscopy, coupled with a CCD camera [24,37]. The accuracy of our technique seems to outperform the accuracy we can estimate from other existing techniques to measure blood flow in the eye by about one order of magnitude [24][25][26].…”

“…Quantitative methods derived from computer vision were adapted to produce a cell migration map with micrometer resolution. We also introduce a combined posterior/anterior eye imaging setup which in addition to traditional FFOCT imaging offers the possibility to measure the blood flow in the anterior eye that compares favorably to existing techniques [24][25][26]. Finally, an approach that combines fluorescence labeling for live cells with static and dynamic FFOCT is presented.…”

High-speed OCT light sources and systems [Invited]

“…However, even in this case, only half of the reference power contributes to the OCT signal, which again leads to a 3 dB sensitivity penalty. In joint-aperture (JA) OCT, multiple passive channels detect light backscattered from outside the illumination aperture [149,150], which increases sensitivity, data rate and image quality, but not A-scan rate.…”

Precision analysis and optimization in phase decorrelation OCT velocimetry

“…Doppler OCT has the disadvantage that only the velocity component parallel to the propagation direction of the light can be measured. Several attempts have been made in the past years to overcome this limitation, among these: Doppler OCT with multiple directions of illumination/detection [15,16], (complex) speckle decorrelation [17][18][19] and Doppler mean and bandwidth analysis [20,21]. Doppler OCT with multiple directions of illumination requires a significant increase in system complexity [15,16], which can be a limiting factor especially if other functionalities should be incorporated.…”

“…Several attempts have been made in the past years to overcome this limitation, among these: Doppler OCT with multiple directions of illumination/detection [15,16], (complex) speckle decorrelation [17][18][19] and Doppler mean and bandwidth analysis [20,21]. Doppler OCT with multiple directions of illumination requires a significant increase in system complexity [15,16], which can be a limiting factor especially if other functionalities should be incorporated. (Complex) speckle decorrelation and Doppler mean and bandwidth analysis requires in general acquisition of large data ensembles for each voxel and velocity estimation [17][18][19].…”