阅读说明：本技术 一种视神经纤维层微小运动检测方法及装置 (Method and device for detecting micro-motion of optic nerve fiber layer ) 是由 秦嘉 安林 于 2020-04-21 设计创作，主要内容包括：本发明公开了一种视神经纤维层微小运动检测方法及装置,获取B扫描的横截面结构图；去除光谱校准后横截面结构图的背景得到前景图；对前景图逐帧处理生成相邻B扫描间的相位差图；通过直方图的方法对相位差图中的每条A线进行相位补偿；判断相位补偿后的相位差图是否产生相位包裹,如果产生相位包裹,进行解包裹,得到包含体运动和组织运动的总相位差曲线；对体运动的相位差曲线进行多项式拟合得到体运动曲线；以总相位差减去拟合的体运动曲线得到组织运动相位差曲线；输出组织运动相位差曲线的图,可以测量到RNFL的微小运动。(The invention discloses a method and a device for detecting micro-motion of an optic nerve fiber layer, which are used for acquiring a cross section structure chart of B scanning; removing the background of the cross section structure chart after the spectrum calibration to obtain a foreground chart; processing the foreground image frame by frame to generate a phase difference image between adjacent B scans; performing phase compensation on each line A in the phase difference diagram by a histogram method; judging whether the phase difference image after phase compensation generates phase wrapping or not, and if the phase wrapping is generated, unwrapping to obtain a total phase difference curve containing body motion and tissue motion; performing polynomial fitting on the phase difference curve of the body motion to obtain a body motion curve; subtracting the fitted body motion curve by the total phase difference to obtain a tissue motion phase difference curve; a map of the tissue motion phase difference curve is output and the minute motion of the RNFL can be measured.)

1. A method for detecting micro-motion of optic nerve fiber layer, which is characterized by comprising the following steps:

acquiring a cross section structure chart of B scanning;

carrying out spectrum calibration of the cross section structure diagram;

removing the background of the cross section structure chart after the spectrum calibration to obtain a foreground chart;

generating a phase difference image between adjacent B scans for the foreground image frame by frame;

performing phase compensation on each line A in the phase difference diagram by a histogram method;

judging whether the phase difference image after phase compensation generates phase wrapping or not, and if the phase wrapping is generated, unwrapping to obtain a total phase difference curve containing body motion and tissue motion;

performing polynomial fitting on the phase difference curve of the body motion to obtain a body motion curve;

subtracting the fitted body motion curve by the total phase difference to obtain a tissue motion phase difference curve;

and outputting a graph of the tissue motion phase difference curve.

2. The method for detecting a micro-motion of an optic nerve fiber layer as claimed in claim 1, wherein the method for performing the spectral calibration of the cross-sectional structure diagram is a method for performing the calibration by any one of an image distortion calibration method, an image spectral curvature correction method, and a wavelength band calibration method.

3. The method for detecting the micro-motion of the optic nerve fiber layer as claimed in claim 1, wherein the method for obtaining the foreground image by removing the background of the cross-section structure image after the spectral calibration is any one of a background foreground segmentation algorithm based on a Gaussian mixture model and a background difference algorithm based on image difference.

4. An optic nerve fiber layer micro-motion image scanning device, which is applied to a cross-sectional structure of B-scan, the device comprising: the system comprises an imaging system, light splitting equipment, an interference system, a scanning device and a detector; the imaging system is used for acquiring a retina pulsation image signal; the imaging system includes: a light source for providing low coherence light; the light splitting equipment divides the low coherent light into two parts to form a first linear light beam and a second linear light beam, and the first linear light beam and the second linear light beam are provided for the interference system; the interference system is used for collecting a part of backward scattered light beams as reference light after the first linear light beams are focused on the fixed reflecting mirror, and collecting a part of backward scattered light beams as sample light after the second linear light beams are focused on a sample to be detected through the scanning device; the reference light and the sample light interfere due to the optical path difference; the scanning device comprises a collimating lens, a fast scanning galvanometer and a slow scanning galvanometer, wherein the second linear light beam forms parallel light through the collimating lens, then sequentially passes through the fast scanning galvanometer and the slow scanning galvanometer and then is focused to a sample to be detected; and the detector is used for receiving an interference optical signal generated by the interference of the reference light and the sample light and converting the optical signal into an electric signal.

5. An optic nerve fiber layer micro-motion image scanning device according to claim 4, characterized in that the scanning speed of the imaging system is 50khz to 100 khz; the sensitivity of the imaging system is 20 dB-180 dB; the imaging range of the imaging system is 3mm multiplied by 3mm to 30mm multiplied by 30 mm.

6. The device as claimed in claim 4, wherein the light source is a broadband light source with a center wavelength of 500-1400nm and a full width half maximum bandwidth of 30-60 nm.

Technical Field

The invention relates to the technical field of imaging measurement and image processing, in particular to a method and a device for detecting micro-motion of an optic nerve fiber layer.

Background

Previous approaches have used at least one B-scan cluster and configurations that calculate OCT angiography data using motion occurring within the eye tissue, and have used the calculated OCT angiography data to derive cross-sectional images of vasculature in the eye tissue, primarily for acquisition of RNFL tissue structure static parameters. Although the main part of the system structure is similar, the retina nerve fiber layer (RNFL for short) can be imaged, and the static parameters of the RNFL tissue structure are mainly obtained; but cannot be applied to wide-range rapid imaging, and the minute motion of RNFL is not measured, so that it is difficult to detect the change of minute parameters of the eye.

Disclosure of Invention

The present invention is directed to a method and an apparatus for detecting a micro-motion of an optic nerve fiber layer, which solves one or more of the problems of the prior art and provides at least one of the advantages.

The invention provides a method for detecting micromotion of optic nerve fiber layers, which comprises the following steps:

acquiring a cross-section structure diagram of B scanning (B-scan, also called B-mode scanning);

carrying out spectrum calibration of the cross section structure diagram;

calculating a background signal;

reading a camera index number (acquiring an index value according to the name of the camera);

setting an initial pointer (initialized image pointer);

removing the background of the cross section structure chart after the spectrum calibration to obtain a foreground chart;

processing the foreground image frame by frame to generate a phase difference image between adjacent B scans;

performing phase compensation on each A line (A-line) in the phase difference diagram by using a histogram method;

judging whether the phase difference image after phase compensation generates phase wrapping or not, and if the phase wrapping is generated, unwrapping to obtain a total phase difference curve containing body motion and tissue motion; body movement refers to shaking of the head of the body, and tissue movement is the movement of each tissue of the eyes.

Performing polynomial fitting on the phase difference curve of the body motion to obtain a body motion curve;

subtracting the fitted body motion curve by the total phase difference to obtain a tissue motion phase difference curve;

and outputting a graph of the tissue motion phase difference curve.

The method for performing the spectral calibration of the cross-section structure chart is to perform calibration by any one of an image distortion calibration method, an image spectral curvature correction method and a waveband calibration method.

The method for removing the background of the cross section structure chart after the spectrum calibration to obtain the foreground image is any one of a background foreground segmentation algorithm based on a Gaussian mixture model and a background difference algorithm based on image difference.

The invention provides a device for scanning a tiny moving image of an optic nerve fiber layer, which comprises: imaging system, beam splitting equipment, interference system, scanning device, detector, image processing module.

The imaging system is used for acquiring a retina pulsation image signal; the scanning speed of the imaging system is 50-100 khz-Hz aline (A scanning); the system sensitivity is 20 dB-180 dB; the imaging range is 3mm multiplied by 3mm to 30mm multiplied by 30 mm; the imaging system includes: a light source for providing low coherence light; the light splitting equipment divides the low coherent light into two parts to form a first linear light beam and a second linear light beam, and the first linear light beam and the second linear light beam are provided for the interference system; meanwhile, receiving the light beam reflected by the interference system and providing the light beam to the detector; the interference system is used for collecting a part of backward scattered light beams as reference light after the first linear light beams are focused on the fixed reflecting mirror, and collecting a part of backward scattered light beams as sample light after the second linear light beams are focused on a sample to be detected through the scanning device; the reference light and the sample light interfere due to the optical path difference; the scanning device comprises a collimating lens, a fast scanning galvanometer and a slow scanning galvanometer, wherein the second linear light beam forms parallel light through the collimating lens, then sequentially passes through the fast scanning galvanometer and the slow scanning galvanometer, and then is focused to a sample to be detected; the detector is used for receiving an interference light signal generated by interference of the reference light and the sample light and converting the light signal into an electric signal; the image processing module is used for processing the electric signal acquired by the detector to realize the reconstruction of the image of the detected sample; the light source is a broadband light source with the central wavelength of 500-1400nm and the full-width half-maximum bandwidth of 30-60 nm;

the image processing module is used for processing the acquired pulse image signal to obtain RNFL integrity information; the processing the acquired pulsating image signal comprises: removing out disordered tissue artifact signals to obtain real pulse signals; and restoring the obtained real pulse signal into an image through an image processing technology, thereby evaluating the integrity of the RNFL.

(1) For assessing RNFL integrity, (2) scan speed of the imaging system > 50khz Aline; the system sensitivity is more than 20 dB; the imaging range is more than 3mm multiplied by 3 mm; the light source is a broadband light source with the central wavelength of 500-1400nm and the full-width half-maximum bandwidth of 30-60 nm. (3) The processing module is used for processing the acquired tissue micro-vibration image signal to obtain RNFL integrity information; the processing of the acquired tissue micro-vibration image signals comprises: removing out disordered tissue artifact signals to obtain real tissue micro vibration signals; and restoring the obtained real tissue micro-vibration signal into an image through an image processing technology, thereby evaluating the integrity of the RNFL.

The method is used for evaluating the integrity of the RNFL, an imaging system is adopted for scanning, and the scanning speed is more than 50khz aline; the system sensitivity is more than 20 dB; the imaging range is more than 3mm multiplied by 3 mm; the light source is a broadband light source with the central wavelength of 500-1400nm and the full-width half-maximum bandwidth of 30-60 nm. The processing module is used for processing the acquired tissue micro-vibration image signal to obtain RNFL integrity information; the processing of the acquired tissue micro-vibration image signals comprises: removing out disordered tissue artifact signals to obtain real tissue micro vibration signals;

the image processing module is used for acquiring a cross section structure diagram of B-scanning (also called B-scanning);

and obtaining a retina blood flow graph, an RNFL-scanning structure graph, a blood flow graph and an RNFL vibration graph in a dynamic parameter processing mode (namely carrying out averaging, structure graph difference, phase difference and other algorithms on the B-scanning cross section), and restoring the obtained real tissue micro vibration signal into an image so as to evaluate the integrity of the RNFL. The RNFL minute vibration is imaged and RNFL integrity is evaluated based on the tissue minute vibration signal.

The dynamic parameter processing mode sequence comprises reading picture data, calibrating spectrum, calculating background signals, reading a camera index number, setting an initial pointer, removing background and a main image processing algorithm part. The image processing algorithm mainly comprises the steps of processing pictures frame by frame, generating a phase difference image between adjacent B scans, performing phase compensation on each line A by using a histogram method in a paper (An L, Subhush H M, Wilson DJ, et al, high-resolution with-field imaging of reliable and tangential tissue microbiological imaging [ J ]. Biomedical Optics,2010,15 (2)), judging whether phase wrapping is generated or not, performing unwrapping if the phase wrapping is generated, obtaining a total phase difference curve containing body motion and tissue motion, performing polynomial fitting on the body motion by using a quadratic polynomial to obtain a body motion curve, subtracting the fitted body motion curve from the total phase difference to obtain a tissue motion phase difference curve, and outputting a curve graph.

The invention provides a method and a device for detecting micro-motion of an optic nerve fiber layer, which can acquire static parameters of a tissue structure of a retina nerve fiber layer; the method can be applied to large-range rapid imaging, and the tiny movement of the retinal nerve fiber layer is measured, so that the change of tiny parameters of the eye is detected.

Drawings

The foregoing and other features of the present disclosure will become more apparent from the detailed description of the embodiments shown in conjunction with the drawings in which like reference characters designate the same or similar elements throughout the several views, and it is apparent that the drawings in the following description are merely some examples of the present disclosure and that other drawings may be derived therefrom by those skilled in the art without the benefit of any inventive faculty, and in which:

FIG. 1 is a flow chart for obtaining a phase difference map;

FIG. 2 is a flow chart of a graph of acquiring a tissue motion phase difference curve.

Detailed Description

The conception, the specific structure, and the technical effects produced by the present invention will be clearly and completely described below in conjunction with the embodiments and the accompanying drawings to fully understand the objects, the features, and the effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.

Fig. 1 is a flowchart of acquiring a phase difference map, fig. 2 is a flowchart of acquiring a tissue motion phase difference curve, and an optic nerve fiber layer micromotion detection method according to an embodiment of the disclosure is explained below with reference to fig. 1 and fig. 2.

Acquiring a cross section structure chart of B scanning;

carrying out spectrum calibration of the cross section structure diagram;

calculating a background signal;

reading a camera index number (acquiring an index value according to the name of the camera);

setting an initial pointer (initialized image pointer);

removing the background of the cross section structure chart after the spectrum calibration to obtain a foreground chart;

processing the foreground image frame by frame to generate a phase difference image between adjacent B scans;

performing phase compensation on each line A in the phase difference diagram by a histogram method;

judging whether the phase difference image after phase compensation generates phase wrapping or not, and if the phase wrapping is generated, unwrapping to obtain a total phase difference curve containing body motion and tissue motion;

performing polynomial fitting on the phase difference curve of the body motion to obtain a body motion curve;

subtracting the fitted body motion curve by the total phase difference to obtain a tissue motion phase difference curve;

and outputting a graph of the tissue motion phase difference curve.

The method for performing the spectral calibration of the cross-section structure chart is to perform calibration by any one of an image distortion calibration method, an image spectral curvature correction method and a waveband calibration method.

The method for removing the background of the cross section structure chart after the spectrum calibration to obtain the foreground image is any one of a background foreground segmentation algorithm based on a Gaussian mixture model and a background difference algorithm based on image difference.

The dynamic parameter processing mode sequence comprises reading picture data, calibrating spectrum, calculating background signals, reading a camera index number, setting an initial pointer, removing background and a main image processing algorithm part. The image processing algorithm mainly comprises the steps of processing pictures frame by frame, generating a phase difference image between adjacent B scans, performing phase compensation on each line A by using a histogram method in a paper (An L, Subhush H M, Wilson DJ, et al, high-resolution with-field imaging of reliable and chromatic aberration with optical aberration [ J ]. biomedicals Optics,2010,15 (2)), judging whether phase wrapping is generated or not, performing unwrapping if the phase wrapping is generated, obtaining a total phase difference curve containing body motion and tissue motion, performing polynomial fitting on the body motion by using a quadratic polynomial to obtain a body motion curve, subtracting the fitted body motion curve from the total phase difference to obtain a tissue motion phase difference curve, and outputting a curve graph.

Detection apparatus for assessing RNFL integrity based on a fundus pulsation signal, the apparatus comprising: the imaging system is used for acquiring a retina pulsation image signal; the scanning speed of the imaging system is more than 50khz Aline; the system sensitivity is more than 20 dB; the imaging range is more than 3mm multiplied by 3 mm; the imaging system includes: a light source for providing low coherence light; the light splitting equipment divides the low coherent light into two parts to form a first linear light beam and a second linear light beam, and the first linear light beam and the second linear light beam are provided for the interference system; meanwhile, receiving the light beam reflected by the interference system and providing the light beam to the detector; the interference system is used for collecting a part of backward scattered light beams as reference light after the first linear light beams are focused on the fixed reflecting mirror, and collecting a part of backward scattered light beams as sample light after the second linear light beams are focused on a sample to be detected through the scanning device; the reference light and the sample light interfere due to the optical path difference; the scanning device comprises a collimating lens, a fast scanning galvanometer and a slow scanning galvanometer, wherein the second linear light beam forms parallel light through the collimating lens, then sequentially passes through the fast scanning galvanometer and the slow scanning galvanometer, and then is focused to a sample to be detected; the detector is used for receiving an interference light signal generated by interference of the reference light and the sample light and converting the light signal into an electric signal; the image processing module is used for processing the electric signal acquired by the detector to realize the reconstruction of the image of the detected sample; the light source is a broadband light source with the central wavelength of 500-1400nm and the full-width half-maximum bandwidth of 30-60 nm;

the processing module is used for processing the acquired pulse image signal to obtain RNFL integrity information; the processing the acquired pulsating image signal comprises: removing out disordered tissue artifact signals to obtain real pulse signals; and restoring the obtained real pulse signal into an image through an image processing technology, thereby evaluating the integrity of the RNFL.

(1) For assessing RNFL integrity, (2) scan speed of the imaging system > 50khz Aline; the system sensitivity is more than 20 dB; the imaging range is more than 3mm multiplied by 3 mm; the light source is a broadband light source with the central wavelength of 500-1400nm and the full-width half-maximum bandwidth of 30-60 nm. (3) The processing module is used for processing the acquired image signals (tissue micro-vibration image signals) to obtain RNFL integrity information; the processing of the acquired tissue micro-vibration image signals comprises: removing out disordered tissue artifact signals to obtain real tissue micro vibration signals; and restoring the obtained real tissue micro-vibration signal into an image through an image processing technology, thereby evaluating the integrity of the RNFL.

The technical problem to be solved is to image the RNFL tiny vibration and evaluate the RNFL integrity based on the tissue tiny vibration signal.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that the present invention is not limited to the details of the embodiments shown and described, but is capable of numerous equivalents and substitutions without departing from the spirit of the invention as set forth in the claims appended hereto.