阅读说明：本技术 一种快速成像相干光层析扫描检眼镜装置 (Quick imaging coherent optical tomography scanning ophthalmoscope device ) 是由 秦嘉 安林 于 2020-04-21 设计创作，主要内容包括：本发明公开了一种快速成像相干光层析扫描检眼镜装置,首先基于大范围扫描出发-采用快速扫描振镜和慢速扫描振镜结合,使用扫描振镜对样品进行实时地快速扫描,系统的成像速率,成像的质量与振镜的扫描直接相关,选择一种合适的振镜是提高系统性能的主要因素。本发明为面向眼部血流快速成像的相干光扫描检眼镜,不仅能够快速成出en face二维图像,还可以获取三维图像,获取的图像信息更全面,可以深入聚焦到组织深层进行成像,成像优点是：二维和三维的成像速度更高,不仅能快速获取感兴趣层的二维信息,更能获取三维空间的总体信息。(The invention discloses a quick imaging coherent optical tomography scanning ophthalmoscope device, which is based on large-range scanning, adopts a combination of a quick scanning galvanometer and a slow scanning galvanometer, uses the scanning galvanometer to quickly scan a sample in real time, has the imaging rate of a system and the imaging quality directly related to the scanning of the galvanometer, and selects a proper galvanometer as a main factor for improving the performance of the system. The invention relates to a coherent light scanning ophthalmoscope for rapid imaging of eye blood flow, which can not only rapidly generate an en face two-dimensional image, but also acquire a three-dimensional image, has more comprehensive acquired image information, can be deeply focused to a deep tissue layer for imaging, and has the advantages that: the two-dimensional and three-dimensional imaging speed is higher, and not only can two-dimensional information of a layer of interest be quickly acquired, but also total information of a three-dimensional space can be acquired.)

1. A rapid imaging coherent optical tomography scanning ophthalmoscope apparatus, comprising: the system comprises a collimation light source, a light splitting module, an interference system, a scanning device, a detector and an acquisition processor;

wherein:

the collimated light source is used for providing a collimated light beam;

the interference system is used for collecting a part of backward scattered light beam as reference light after the first linear light beam is focused on the fixed reflector, and a part of backward scattered light beam is used as sample light after the second linear light beam is 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 interference system is used for collecting partial light beams scattered by the first linear light beam after passing through the fixed reflector as reference light and partial light beams scattered by the second linear light beam after passing through the scanning device as sample light;

the scanning device comprises a fast scanning galvanometer and a slow scanning galvanometer, and the second linear light beam sequentially passes through the fast scanning galvanometer and the slow scanning galvanometer to reach a sample to be detected for scanning;

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;

and the acquisition processor is used for acquiring the signals detected by the detector, processing the image signals by using an image processing algorithm to obtain image information in the signals and further reconstructing a three-dimensional image of the measured object.

2. The rapid imaging coherent optical tomography device as claimed in claim 1, wherein the collimated light source is a laser source having a central wavelength of 840nm, a bandwidth range of ± 5nm, an average power of 20mW, and an axial resolution of 1 μm to 12 μm.

3. The apparatus of claim 1 wherein the fast scan galvanometer employs EOPC SC30-3X4-5-16KH, mirror dimensions 3mm X4 mm, scan angle 5 degree, resonant galvanometer.

4. The device of claim 1, wherein the slow-scan galvanometer employs Cambridge Technology 6210H, 671-1-FS40, galvanometer XY combination, aperture size 7mm, wavelength range broadband coating: 350nm-12 μm, and the maximum scanning angle is 40 degrees.

5. A rapid imaging coherent optical tomography device as claimed in claim 1 wherein the imaging range of the ophthalmoscope device is from 6 x 6mm to 12 x 12 mm.

6. The apparatus of claim 1, wherein the three-dimensional image is reconstructed by any one of Shading, Texture, Stereo, Motion, Photometric, Silhouettes, and Defocus.

7. The fast imaging coherent optical tomography ophthalmoscope apparatus of claim 1 wherein the image processing algorithm comprises image differencing and moving average smoothing.

Technical Field

The invention relates to the technical field of OCT (optical coherence tomography) scanning technology and scanning ophthalmoscope, in particular to a rapid imaging coherent optical tomography scanning ophthalmoscope device.

Background

Compared with other technologies, although a hardware basis for integrating a binocular stereoscopic vision three-dimensional imaging system and a fundus OCT system exists, images are corrected by using improvement on an algorithm, and then data splicing is carried out to realize high-resolution, large-range and clear fundus OCT three-dimensional structure imaging and blood flow imaging, so that an effective basis is provided for diagnosis of diseases related to changes of the fundus structure and blood flow. Blood flow analysis is performed on a B-scan (B-scan) cross section, which is a commonly used method at present. A conventional adaptive-based SLO system identifies information about a blood flow velocity of the blood vessel by identifying an SLO image obtained based on signal light having a focus position deeper than at least a part of the region of the blood vessel, where SLO denotes a scanning laser ophthalmoscope, and a conventional scanning laser ophthalmoscope can acquire only en face two-dimensional information, and cannot acquire three-dimensional image information.

Disclosure of Invention

The present invention is directed to a fast imaging coherent optical tomography ophthalmoscope apparatus, which solves one or more of the problems of the prior art and provides at least one of the advantages of the apparatus.

The invention designs a rapid imaging coherent light tomography scanning ophthalmoscope device, which is a coherent light scanning ophthalmoscope facing the rapid imaging of eye blood flow, not only can rapidly generate an en face two-dimensional image (the en face two-dimensional image is en face-OCT, which is a so-called C-scan image processed by software operation on the basis of the traditional high-density B-scan and can provide plane images of different depth levels of retina and choroid), but also can acquire a three-dimensional image, the acquired image information is more comprehensive, and the image can be deeply focused to a deep tissue layer for imaging, and the imaging advantage is as follows: the two-dimensional and three-dimensional imaging speed is higher, and not only can two-dimensional information of a layer of interest be quickly acquired, but also total information of a three-dimensional space can be acquired.

The invention provides a fast imaging coherent optical tomography scanning ophthalmoscope device, comprising: the system comprises a collimation light source, a light splitting module, an interference system, a scanning device, a detector and an acquisition processor;

wherein:

the collimated light source is used for providing a collimated light beam;

the light splitting module splits the collimated light beam into two parts to form a first linear light beam and a second linear light beam which 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 partial light beams scattered by the first linear light beam after passing through the fixed reflector as reference light and partial light beams scattered by the second linear light beam after passing through the scanning device as sample light;

the scanning device comprises a fast scanning galvanometer and a slow scanning galvanometer, and the second linear light beam sequentially passes through the fast scanning galvanometer and the slow scanning galvanometer to reach a sample to be detected for scanning;

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;

and the acquisition processor is used for acquiring the signals detected by the detector, processing the image signals by using an image processing algorithm to obtain image information in the signals and further reconstructing a three-dimensional image of the measured object.

And an acquisition processor for acquiring the signals detected by the detector and obtaining image information in the signals by using image difference (subtracting corresponding pixel values of two images to weaken similar parts of the images and highlight changed parts of the images) and Movingaverage (moving average) methods, and further performing three-dimensional image reconstruction of the object to be measured.

Further, the collimation light source is a laser light source, the central wavelength of the laser light source is 840nm, the bandwidth range is +/-5 nm, the average power is 20mW, and the axial resolution is 1-12 μm.

Furthermore, the fast scanning galvanometer adopts an EOPC SC30-3X4-5-16KH, a mirror surface with the size of 3mm multiplied by 4mm, a scanning angle of 5 degrees and a resonance galvanometer.

Further, the slow-speed scanning galvanometer adopts Cambridge Technology 6210H, 671-1-FS40, a galvanometer XY combination, an aperture size of 7mm, a wavelength range broadband coating: 350nm-12 μm, and the maximum scanning angle is 40 degrees.

Further, the ophthalmoscope device has an imaging range of 6 × 6mm to 12 × 12 mm.

Further, the method for reconstructing the three-dimensional image is any one of Shading, Texture, Stereo, Motion, Photometric, Silhouettes and Defocus.

Further, image processing algorithms include image difference and moving average smoothing methods.

The invention provides a rapid imaging coherent light tomography scanning ophthalmoscope device, which realizes high-resolution, large-range and clear retinal en face imaging and can acquire structure and blood flow characteristics; and a two-dimensional image (en face image) in the whole chromatographic surface direction can be obtained through one-time imaging, and imaging of each surface to be detected can be realized by adjusting the optical path difference of the reference arm and the sample arm, so that pathological changes of a retina layer in a large field range can be observed, and comprehensive detection and evaluation of the retina are facilitated. The method can not only quickly generate the two-dimensional image of the en face, but also acquire the three-dimensional image, the acquired image information is more comprehensive, the deep layer of the tissue can be deeply focused for imaging, and the imaging advantage is as follows: the two-dimensional and three-dimensional imaging speed is higher, and not only can the two-dimensional information of the interested layer be rapidly acquired, but also the three-dimensional overall signal of the tissue can be acquired.

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 schematic diagram of transverse blood flow analysis of a rapid imaging coherent optical tomography scanning ophthalmoscope apparatus;

FIG. 2 is a schematic diagram of a conventional B-scan blood flow analysis.

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 schematic view showing a transverse blood flow analysis of a rapid imaging coherent optical tomography ophthalmoscope apparatus, fig. 2 is a schematic view showing a conventional B-scan blood flow analysis, and a rapid imaging coherent optical tomography ophthalmoscope apparatus according to an embodiment of the present disclosure will be described with reference to fig. 1 and 2.

The technical scheme of the system is mainly based on hardware and algorithm software improvement of an ophthalmoscope to realize high-resolution, large-range and clear retina en face imaging and obtain structure and blood flow characteristics, and specifically is shown in figure 1.

The invention provides a fast imaging coherent optical tomography scanning ophthalmoscope device, comprising: the system comprises a collimation light source, a light splitting module, an interference system, a scanning device, a detector and an acquisition processor;

wherein:

the collimated light source is used for providing a collimated light beam;

the light splitting module splits the collimated light beam into two parts to form a first linear light beam and a second linear light beam which 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 partial light beams scattered by the first linear light beam after passing through the fixed reflector as reference light and partial light beams scattered by the second linear light beam after passing through the scanning device as sample light;

the scanning device comprises a fast scanning galvanometer and a slow scanning galvanometer, and the second linear light beam sequentially passes through the fast scanning galvanometer and the slow scanning galvanometer to reach a sample to be detected for scanning;

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;

and the acquisition processor is used for acquiring the signals detected by the detector, processing the image signals by using an image processing algorithm to obtain image information in the signals and further reconstructing a three-dimensional image of the measured object.

And an acquisition processor for acquiring the signals detected by the detector and obtaining image information in the signals by using image difference (subtracting corresponding pixel values of two images to weaken similar parts of the images and highlight changed parts of the images) and Movingaverage (moving average) methods, and further performing three-dimensional image reconstruction of the object to be measured.

Compared with other technologies, although a hardware basis for integrating a binocular stereoscopic vision three-dimensional imaging system and a fundus OCT system exists, images are corrected by using improvement on an algorithm, and then data splicing is carried out to realize high-resolution, large-range and clear fundus OCT three-dimensional structure imaging and blood flow imaging, so that an effective basis is provided for diagnosis of diseases related to changes of the fundus structure and blood flow. Blood flow analysis is performed on a B-scan cross section, see fig. 2, in a currently common manner.

The design idea is as follows: firstly, based on large-range scanning, a combination of a fast scanning galvanometer and a slow scanning galvanometer is adopted, and the emphasis is to firstly obtain line scanning by using the fast scanning galvanometer and then quickly obtain a two-dimensional enface image by using the other scanning galvanometer. In the OCT system, a scanning galvanometer is used for rapidly scanning a sample in real time, and the imaging speed and the imaging quality of the system are directly related to the scanning of the galvanometer. The two factors influencing the performance of the galvanometer are response time and linearity, the response time determines the scanning frequency of the galvanometer, and the linearity directly reflects the linear relation between a control signal and linear motion. Therefore, the selection of a suitable galvanometer is a major factor in improving system performance. Therefore, in order to realize real-time scanning and ensure the image scanning precision, in the scheme of the application, the fast scanning galvanometer adopts an EOPC SC30-3X4-5-16KH, the mirror surface size is 3mm multiplied by 4mm, the scanning angle is 5 degrees, and the resonant galvanometer is resonant; the slow-speed scanning galvanometer adopts Cambridge Technology 6210H, 671-1-FS40, galvanometer XY combination, aperture size of 7mm and wavelength range broadband coating: 350nm-12 μm, and the maximum scanning angle is 40 degrees; because the scanning frequency is ultrahigh like this, can ultrafast, realize on a large scale, accurate one-dimensional scanning in the two-dimensional scanning, realize on a large scale two-dimensional scanning then fast, can realize the formation of image of whole eye ground position several seconds, acquire the interesting position organizational structure of eye ground and blood flow information fast.

Secondly, the selection of the collimation light source is also based on the requirement of fast scanning preferentially, the narrow bandwidth is positioned minus or plus 5nm, the narrow band light source is mainly convenient for fast imaging, and the influence of the movement of the eyeball along the optical axis direction on the image quality is reduced. Because of the longitudinal resolution, under the condition that the central wavelength is determined, the bandwidth is wider, the longitudinal resolution is larger, the sensitivity to eyeball motion is higher, the bandwidth is narrower, the longitudinal resolution is smaller, and the influence of eyeball motion is not easy to be caused; therefore, although the longitudinal resolution is reduced, the influence of the movement of the eyeball, the head, and the like on the image quality is reduced, which is more important for acquiring a wide-range image. And secondly, the bandwidth of +/-5 nm is beneficial to focusing on a certain interested biological tissue layer for imaging, and the influence of chromatic dispersion is reduced. In addition, the cost of narrowband lasers is often lower than broadband light sources from a cost perspective, which is also a factor considered by the present application. And finally, in the consideration of balancing longitudinal resolution and transverse resolution, selecting the central wavelength of the light source as the central wavelength of the laser light source, wherein the central wavelength of the laser light source is 840nm, the bandwidth range is +/-5 nm, the average power is 20mW, and the axial resolution is less than 12 microns.

And finally, optimizing by the acquisition processor, so that the acquisition processor can obtain image information by using a difference algorithm and a moving average algorithm and can reconstruct a three-dimensional image of the detected sample.

Further, image processing algorithms include image difference and moving average smoothing methods.

Wherein the image processing algorithm is the method shown in fig. 1, comprising: acquiring an original two-dimensional photographed En face structural image, and calibrating and aligning the image of the En face structural image; calculating blood flow data according to an image difference algorithm; quantitatively analyzing blood flow data;

therefore, after the retina is rapidly scanned in two dimensions through hardware improvement, static tissue and dynamic blood flow information are distinguished through a difference algorithm and a moving average algorithm, so that functional information such as blood flow is finally obtained, and an imaging range of 6 x 6mm-12 x 12mm can be obtained. The advantages are that the method can rapidly scan in a large field range to realize large-range extraction of blood flow information of the superficial layer, the deep layer and the choroid of the retina and obtain macroscopic information of fundus blood flow, and mainly carries out blood flow analysis transversely through en face imaging.

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.