Correction method and system of sweep frequency OCT digital phases based on information on static regions

Abstract

The invention discloses a correction method and system of sweep frequency OCT digital phases based on information on static regions. Desynchrony in sweep-initiating of a swept source and sampling clock signals, and random offset of an interference signal spectrum presented in conventional swept source optical coherence tomography may give rise to random jumping of OCT phase signals. The research shows that in the static regions of a sample, phase noise decided by a system SNR is lower as compared with a phase jumping error while environment-induced phase disturbance in the time domain has the feature of slow variation. By utilization of the above phase features, A-line positions where phase jumping occurs and offset amount of the spectrum are determined. By means of a linear relation between phase and imaging depth, correction of phase jumping errors can be achieved. The method belongs to pure digital correction without increase in complexity of the system and introduction to extra phase noise.

Description

technical field [0001] The present invention relates to swept-frequency optical coherence tomography (SweptSourceOpticalCoherenceTomography, SS-OCT) and functional imaging technologies such as optical Doppler and microvascular optical contrast, and in particular to a sweep-oct digital phase compensation correction method based on static area information and system. technical background [0002] The contrast of traditional OCT imaging mainly comes from the spatial variation of the backscatter coefficient inside the sample, which forms the structural imaging inside the sample. Due to the single contrast, structural OCT is not very disease-specific in clinical diagnosis. In view of this, scholars have carried out a lot of work in exploring the new contrast mechanism of OCT, and formed a series of OCT with expanded functions. Compared with structural imaging, these technologies comprehensively use the intensity and phase information of OCT signals to obtain physiological funct...

AI Technical Summary

Problems solved by technology

The hardware approach increases system complexity and increases cost

The digital correction method generally uses the signal at a fixed noise position (inherent noise caused by system end surface reflection) to calculate the spectral shift of the interference signal through an iterative or fitting method, but the iterative method has a large amount of calculation and takes a long time. Practical; the problem with the fitting method is low stability and residual phase noise

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