Endoscopic OCT imaging system adopting optical path difference external compensation common-path interference probe

Abstract

The invention discloses an endoscopic OCT imaging system adopting an optical path difference external compensation common-path interference probe. The system comprises a light source, an optical path difference external compensation interferometer, a first acousto-optic frequency shifter, a second acousto-optic frequency shifter, an optical circulator, a fiber optic rotary joint, a spiral scanning mechanism, an endoscopic probe, a glass spacer, a Grin lens, a 45-degree cylinder mirror, a transparent sealing sleeve, an outer metal sheath, a diaphragm, a detector, a data acquisition card and a computer. According to the system, the front end face of the Grin lens in the endoscopic lens serves as the reference surface, and compensation of the optical path difference between the front end face of the Grin lens and a sample is achieved through the optical path difference external compensation interferometer; lesion inspection missing is reduced through spiral traversal scanning, light dispersion usually caused by the cylindrical transparent sealing sleeve is eliminated through the planar diaphragm, and false images existing in an imaging result are eliminated through combination of the acousto-optic frequency shifters and the signal filtering and demodulation technology. The system has the advantages that antijamming capability is high, the probe can be used as soon as being plugged, lesion inspection missing is reduced, interference of false images is avoided, and inlet sample light beams are not dispersed.

Description

technical field [0001] The invention relates to medical endoscopic imaging technology and optical coherence tomography imaging technology, in particular to an endoscopic optical coherence tomography imaging system adopting optical path difference external compensation common path interference endoscopic probe and helical scanning imaging mode. Background technique [0002] Through the endoscope, doctors can directly observe the tissue morphology and lesions of the internal organs of the human body, and can also perform surgical treatment on the lesions. Traditional endoscopes can only observe the surface morphology of internal organs, and lesions often occur inside the organs first. Many imaging techniques with tomographic capabilities, such as: computer tomography, nuclear magnetic resonance, X-ray and ultrasound, are playing an important role in clinical diagnosis, but these techniques can only provide 0.1-1mm resolution, which is far from the detection The level of resol...

AI Technical Summary

Problems solved by technology

The problems existing in these systems are as follows: 1) Only one imaging mode of spectral domain OCT is used, and there is no possibility of adopting frequency-sweeping OCT imaging mode, so different imaging modes cannot be used according to different application occasions to give full play to their respective advantages; 2) It is not traversing scanning imaging, and there is a possibility of missed detection of lesions; 3) The serious astigmatism problem that will be caused when the beam of incident sample passes through the cylindrical transparent sealing sleeve is not considered

[0005] In the frequency-sweeping OCT system proposed by Yang Yaliang et al. (Yang Yaliang et al., helical scanning co-path interference type endoscopic frequency-sweeping OCT real-time imaging method and system, invention patent: ZL2012100277848), the spectroscopic device and reference mirror are placed on the probe Internally, a common path interference endoscopic probe is formed, and a micro motor installed inside the probe is used to realize the helical scanning imaging at the top. The advantage of the top scanning is that it is stable, but the system still has the following problems: 1) Spectroscopic devices, reference mirrors, and the distance between the two to match the optical path of the sample beam, as well as the micro-motor, etc., make the unbendable part of the probe tip longer, which will make it difficult for the probe to pass through the oral cavity, the Y-shaped entrance of the electronic endoscope instrument channel, etc., so that it is not easy to into the body; 2) The micro-motor only performs helical scanning motion in the inner space of the tip of the probe, and the travel is very limited, which is difficult to meet the actual needs of lesion detection; 3) Only one imaging mode of frequency-sweeping OCT is used, and no spectral imaging mode is provided. 4) The astigmatism problem caused by the light beam passing through the cylindrical transparent sealing sleeve is not considered

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