Noise reduction device for magnetic optical coherence tomography

Abstract

The invention discloses a noise reduction device for magnetic optical coherence tomography. The device comprises a top cover, a cylinder and an angle adjustment base. The cooperation between thread and external thread realizes the thread transmission connection; the angle adjustment base includes a panel and a bottom plate, one end of the panel and the bottom plate is connected by a hinge structure, and the other end is connected by a cover screw, the cylinder is fixedly connected to the panel, and the cover is opened by twisting The screw and the panel drive the cylinder to rotate around the shaft of the hinge structure; a movable sample placement table is arranged inside the cylinder. The noise reduction device for magnetic optical coherence tomography provided by the present invention has a simple structure and is convenient to adjust. The reference light and the sample light share an optical path, which reduces the optical path difference between the sample light and the reference light by the scanning galvanometer. The influence of magnetic field modulation noise is effectively suppressed, and the imaging quality is improved under the condition of ensuring high scanning speed.

Description

technical field [0001] The invention relates to the technical field of optical imaging, in particular to a noise reduction device for magnetic-dynamic optical coherence tomography. Background technique [0002] Optical coherence tomography (OCT) is a high-resolution, depth-resolving imaging method. Magneto-motion optical coherence tomography (MM-OCT) is a functional extension of OCT. Its principle is to use OCT to detect the movement of magnetic nanoparticles (MNPS) in tissue driven by an external magnetic field, so as to track MNPS. [0003] At present, there are still some problems when MM-OCT is used to trace MNPS. The motion generated by magnetic field modulation MNPS is the basis of imaging. However, the alternating magnetic field will also affect the detection end of the system and generate modulated vibration noise. This is because the optical path at the detection end of the system is fixedly connected to the optical-mechanical components. Some optical-mechanical c...

AI Technical Summary

Problems solved by technology

The vibration of the detection arm will be superimposed with the normal nanoparticle vibration signal, resulting in motion artifacts in areas without MNPS

The sample arm of traditional MMOCT is separated from the reference arm. When the magnetic field causes the ferromagnetic material in the sample arm to vibrate, the reference arm is not affected because it is far away from the magnetic field. At this time, the sample arm moves relative to the reference arm. Since the MMOCT imaging extracts the reference arm The relative motion signal between the arm and the sample arm (the optical path difference change signal between the reference light and the sample light) will produce artifacts of the sample motion during imaging. Therefore, for the MMOCT imaging system, there is an urgent need for a Detection method or device to realize effective elimination of modulation noise

[0004] The document "Intravascular magnetomotive optical coherence tomography oftargeted early-stage atherosclerotic changes in ex vivo hyperlipidemic rabbit ortas.J Biophotonics 2016Jan; 9(1-2):109-16" discloses a MM-OCT detection device, all components of the device None of them contain ferromagnetic substances, including custom-made MMOCT sample arms without ferromagnetic substances to eliminate magnetic field modulation noise. This method uses a motorized stage to drive the detection end to scan horizontally to obtain a two-dimensional image. Although this method solves the problem of magnetic noise problem, but the motor scan speed is slow, can't achieve fast scan

Under normal conditions, the OCT system uses a two-dimensional galvanometer to scan to increase the scanning speed. However, the scanning galvanometer contains a coil inside, which is equivalent to a magnet after being powered on. It will vibrate in response to the modulation of an external magnetic field, resulting in a gap between the sample light and the reference light. The optical path difference changes, resulting in artifacts of the sample movement, so under the condition that the scanning galvanometer is used to increase the scanning speed, the problem of eliminating modulation noise still needs to be solved

Images