Method and system based on double-space carrier frequency technology for increasing OCT (optical coherence tomography) imaging depth

Abstract

The invention discloses a method and a system based on double-space carrier frequency technology for increasing OCT (optical coherence tomography) imaging depth. Two reference arms different in optical path are arranged in a Fourier domain OCT system and interfere with sample light signals different in depth position. A scanning galvanometer system is arranged in each of the reference arms, so that incident positions, of light beam in the reference arms, on scanning galvanometers have different offset quantities relative to rotating shafts of the scanning galvanometers. The scanning galvanometers in a sample arm and the reference arms are enabled to scan synchronously through a synchronous control circuit. Due to space phase modulating effect of the scanning galvanometers in the reference arms, interference spectrum signals corresponding to two depth positions of a sample are loaded to different transverse space frequency spectrum bands respectively. Modulated interference spectrum signals which are detected are demodulated through a computer to acquire two OCT images corresponding to different depth positions of the sample, and multiple increase of OCT imaging depth can be realized through simple splicing.

Description

technical field [0001] The present invention relates to optical coherence tomography imaging technology, in particular to a method and system for extending OCT imaging depth based on dual space carrier frequency technology. Background technique [0002] Optical coherence tomography (OCT) is a new biomedical optical imaging technology, which can realize non-contact, non-destructive, high-resolution imaging of the structure and physiological functions of biological tissues, and can be used in early detection of diseases and It has a broad application prospect in the field of body biopsy. OCT was originally used for imaging of the human retina and has been widely used in clinical ophthalmology, especially for the early prevention and diagnosis of some diseases such as diabetic retinopathy and glaucoma. In many OCT medical applications a large imaging depth is highly desirable. For example, in endoscopic applications, where the probe and tissue surface cannot be precisely cont...

AI Technical Summary

Problems solved by technology

The method of eliminating mirror images mainly includes B-M-mode. When using this method, there will be a problem of image quality degradation due to the decrease of lateral sensitivity, and it is also easy to bring in environmental interference.

By switching the reference arm, the imaging stitching technology is usually realized by switching the galvanometer, but the switching process will bring a time difference, resulting in the later stitching being the imaging of samples in different periods and different states, which cannot meet the requirements of simultaneous imaging

Using two sets of spectrometers to image simultaneously will increase the experimental equipment and cost, and will also increase the complexity of the entire device

Segmented spectral expansion imaging divides the light source into two parts and utilizes them separately by setting a dichroic mirror. Although it can expand the imaging depth and is synchronous without switching period, the resulting image resolution will be lost by half.

Images