CN210810980U - An ultra-wide-range skin imaging device - Google Patents

Abstract

The utility model discloses an ultra-wide-range skin imaging device, comprising a light source, an optical fiber coupler, a reference arm device, a sample arm device, a spectrometer device and a computer processing terminal; the reference arm device includes a first collimating lens and Reflecting mirror, the first collimating lens and the reflecting mirror are connected by light; the sample arm device includes a second collimating lens, a two-dimensional galvanometer scanning system and a first focusing lens, and the spectrometer device includes a second collimating lens connected by light. Three collimating lens, grating, triangular prism, second focusing lens and image acquisition module, the light source, the first collimating lens, the second collimating lens and the third collimating lens are all connected with the fiber coupler through optical fibers . The skin imaging device of the utility model performs real-time large-scale imaging of the skin to be measured, and increases the imaging range in the depth direction by improving the spectral resolution of the spectrometer device.

Description

An ultra-wide-range skin imaging device

technical field

The utility model relates to the technical field of OCT imaging, in particular to an ultra-wide range skin imaging device.

Background technique

The skin is the largest organ of the human body and a very important organ of the human body. Optical coherence tomography (OCT) is a cross-sectional imaging technology based on the principle of low-coherence light interference. With its high resolution, real-time and non-contact advantages, it has broad application prospects in the clinical diagnosis of human skin diseases. . Such as skin cancer (such as basal cell carcinoma), port-wine stains, skin vascular disease diagnosis and treatment.

However, SDOCT has certain limitations in the application of skin. In the SDOCT system, the interference signal between the sample arm and the reference arm is received by the spectrometer. The spectral resolution of the spectrometer is constrained by the spectral capability of the grating and the pixel size of the camera, and the spectral resolution determines the imaging range of the system. The imaging depth of traditional spectrometers can reach about 3mm. As the depth deepens, the sensitivity of the system decreases continuously. When the imaging depth reaches 2mm, the sensitivity of the system decreases by about 12dB, which shows that the image quality decreases with the depth. However, the thickness of human skin ranges from 0.5 to 4 mm, and blood vessels are located in the dermis and below. Traditional OCT system imaging cannot well meet the needs of skin structure imaging or skin vascular imaging. Therefore, it is essential to develop a super-wide-angle skin imaging device. How to increase the imaging range in the depth direction, that is, how to improve the spectral resolution of the spectrometer, and how to expand the imaging urgently need to be solved.

In the prior art, the patent application number CN200910076054.5 for "real-time imaging optical coherence tomography skin diagnostic equipment" can realize real-time rapid imaging of skin everywhere in the human body, while the patent application number CN201711340695.8 for "application to vascular skin diseases" The "Detection and Positioning Device and System and Working Method" patent achieves the same scanning position before and after, and has high detection stability, but these two patents are aimed at small-scale imaging and do not improve the detection depth.

Utility model content

The technical problem to be solved by the utility model is that the imaging range in the imaging depth direction of the existing OCT imaging system is small.

The utility model provides an ultra-wide range skin imaging device, which increases the imaging range in the imaging depth direction by improving the spectral resolution.

The solution that the utility model solves its technical problem is:

An ultra-wide-range skin imaging device, comprising: a light source, an optical fiber coupler, a reference arm device, a sample arm device, a spectrometer device and a computer processing terminal; the reference arm device includes a first collimating lens and a reflector, the The first collimating lens and the reflector are connected by light;

The sample arm device includes a second collimating lens, a two-dimensional galvanometer scanning system and a first focusing lens. The light emitted from the second collimating lens is deflected by the two-dimensional galvanometer scanning system and then enters the first focusing lens. The outgoing light of a focusing lens enters the skin to be tested;

The spectrometer device includes a third collimating lens, a grating, a triangular prism, a second focusing lens, and an image acquisition module connected by light rays. The light emitted from the third collimating lens passes through the grating and the triangular prism in sequence, and the output of the triangular prism is The incident light enters the image acquisition module after passing through the second focusing lens;

The light source, the first collimating lens, the second collimating lens and the third collimating lens are all connected with the optical fiber coupler through optical fibers, and the image acquisition module and the two-dimensional galvanometer scanning system are processed with the computer Terminal electrical connection.

As a further improvement of the above technical solution, the two-dimensional galvanometer scanning system is connected to the computer processing terminal through a data acquisition card.

As a further improvement of the above technical solution, the image acquisition module is connected to the computer processing terminal through an image acquisition card.

As a further improvement of the above technical solution, the image acquisition module is a line array CCD camera.

As a further improvement of the above technical solution, the light source is a light emitting diode with a wavelength of 1310 nm.

The beneficial effects of the utility model are: the skin imaging device of the utility model performs real-time large-scale imaging of the skin to be measured, and increases the imaging range in the depth direction by improving the spectral resolution of the spectrometer device.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly describes the accompanying drawings that are used in the description of the embodiments. Obviously, the described drawings are only a part of the embodiments of the present invention, but not all of the embodiments, and those skilled in the art can also obtain other design solutions and drawings according to these drawings without creative work.

Fig. 1 is the schematic diagram of the device structure of the embodiment;

2 is a schematic diagram of a device scan path of an embodiment;

FIG. 3 is a flowchart of the processing of the interference light signal by the computer processing terminal of the embodiment.

Detailed ways

The concept, specific structure and technical effects of the present utility model will be described clearly and completely below in conjunction with the embodiments and the accompanying drawings, so as to fully understand the purpose, characteristics and effects of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, those skilled in the art can obtain other embodiments without creative work, All belong to the scope of protection of the present invention. In addition, all connection relationships mentioned in the text do not mean that the components are directly connected, but refer to a better connection structure that can be formed by adding or reducing connection accessories according to specific implementation conditions. Various technical features in the creation of the present invention can be combined interactively on the premise of not contradicting each other.

Embodiment 1, referring to FIG. 1 , an ultra-wide-range skin imaging device includes: a light source 100, a fiber coupler 200, a reference arm device 300, a sample arm device 400, a spectrometer device 500 and a computer processing terminal 600; the reference the first collimating lens 301 and the reflecting mirror 302 included in the arm device 300, the first collimating lens 301 and the reflecting mirror 302 are connected by light;

The sample arm device 400 includes a second collimating lens 401 , a two-dimensional galvanometer scanning system 402 and a first focusing lens 403 , and the light emitted from the second collimating lens 401 is deflected by the two-dimensional galvanometer scanning system 402 and then enters the the first focusing lens 403, the outgoing light of the first focusing lens 403 enters the skin to be tested 700;

The spectrometer device 500 includes a third collimating lens 501 , a grating 502 , a triangular prism 503 , a second focusing lens 504 and an image acquisition module 505 connected by light rays, and the light emitted from the third collimating lens 501 sequentially passes through the grating 502 and the triangular prism 503, the outgoing light of the triangular prism 503 passes through the second focusing lens 504 and then enters the image acquisition module 505;

The light source 100 , the first collimating lens 301 , the second collimating lens 401 and the third collimating lens 501 are all connected with the optical fiber coupler 200 through optical fibers, and the image acquisition module 505 and the two-dimensional galvanometer scanning system 402 are all electrically connected to the computer processing terminal 600 .

The light beam emitted by the light source 100 enters the fiber coupler 200 and is divided into a first beam and a second beam, the first beam enters the reference arm device 300, and the second beam enters the sample arm device 400, the fiber coupler 200 in this embodiment The splitting ratio is 50:50. The first light beam is collimated by the first collimating lens 301 and then directed to the reflector 302 , and the first light beam returns to the fiber coupler 200 along the original path under the action of the reflector 302 .

The outgoing light collimated by the second light beam through the second collimating lens 401 enters the two-dimensional galvanometer scanning system 402 , and the outgoing light from the two-dimensional galvanometer scanning system 402 passes through the first focusing lens 403 and then the skin to be tested 700 scans along a preset scanning path, the scanned light beam is scattered on the surface of the skin to be tested 700, and the scattered light enters the optical fiber through the first focusing lens 403, the two-dimensional galvanometer scanning system 402 and the second collimating lens 401 in sequence Coupler 200.

The first light beam returning to the fiber coupler 200 interferes with the scattered light to generate an interference light signal, the interference light signal includes the image information of the skin 700 to be tested, and the fiber coupler 200 outputs the interference light signal to the spectrometer Device 500. The interference light signal is collimated through the third collimating lens 501 , the emitted light from the third collimating lens 501 passes through the grating 502 and the triangular prism 503 for beam splitting in sequence, and the split interference light signal passes through the second focusing lens 504 Then enter the image acquisition module 505 , and the image acquisition module 505 sends the acquired spectral interference light signal to the computer processing terminal 600 .

As a preferred embodiment, the image acquisition module 505 is connected to the computer processing terminal 600 through an image acquisition card.

The interference light signal carries the image information of the skin 700 to be tested, and the computer processing terminal 600 is connected with the image acquisition module 505 through an image acquisition card.

The computer processing terminal 600 performs Fourier transform and background denoising processing on the received interference light signal containing the image information of the skin 700 to be tested, and then uses a phase compensation algorithm to eliminate motion artifacts to obtain a de-artifact image. The dimensional cross-correlation algorithm calculates the image offset between adjacent de-artifacted images, calibrates the motion offset between adjacent de-artifacted images, performs image matching, and finally uses the SURF-based image stitching algorithm to process the image. After splicing, an imaging image of the skin to be tested 700 is finally obtained.

The spectrometer device 500 includes a third collimating lens 501, a grating 502, a triangular prism 503, a second focusing lens 504, and an image acquisition module 505. The grating 502 and the triangular prism 503 are used as dispersion elements of the spectrometer device 500, wherein the grating 502 is formed by The wavelength diffraction angle conducts light splitting, the triangular prism 503 splits light with the wavelength index of refraction, the interference light signal passes through the grating 502 for the first layer of light splitting, and then passes through the triangular prism 503 for the second layer of light splitting. The grating 502 and the triangular prism 503 serve as two The dispersive element can increase the spectral resolution and convert the spectrum from the wavelength domain to the wavenumber domain, which can not only deepen the imaging depth, but also achieve accurate spectral calibration on the mechanical structure without the need for software algorithms, which greatly simplifies the image processing process. Improve device performance.

The skin imaging device can achieve an imaging depth of 6 mm, and when the imaging depth reaches 2 mm, the system sensitivity of the spectrometer device 500 only loses 6 dB, which effectively ensures the imaging image quality.

The two-dimensional galvanometer scanning system 402 is used to adjust the direction of the light beam. The two-dimensional galvanometer scanning system 402 is composed of an X-direction mirror and a Y-direction mirror, and performs scanning in the X-direction and Y-direction respectively. The direction represents the horizontal scan, and the Y direction represents the vertical scan. When the scanning in the Y direction is 0, two-dimensional scanning, that is, cross-sectional imaging, is realized; when the scanning in the Y direction is not 0, three-dimensional scanning is realized, that is, three-dimensional imaging is realized. The two-dimensional galvanometer scanning system 402 is electrically connected to the computer processing terminal 600, and the computer processing terminal 600 controls the two-dimensional galvanometer scanning system 402 to adjust the scanning speed and scanning path of the light beam.

Referring to FIG. 2 for the preset scanning path, in the process of scanning and imaging, the imaging size of 2*2mm is used as the primitive, and the skin to be tested 700 is scanned sequentially in the S-shaped scanning sequence, and 2*2mm is used as the primitive. The adjacent scanning areas of 100 have overlapping parts. After completing the preset scanning path, the scanning signals of multiple scanning areas are acquired. The image acquisition module 505 collects the interference light signals including the scanning signals of these scanning areas, and the interference The optical signal is sent to the computer processing terminal 600 .

As a further preferred embodiment, the two-dimensional galvanometer scanning system 402 is connected to the computer processing terminal 600 through a data acquisition card.

The computer processing terminal 600 realizes the scanning of the skin to be tested 700 by adjusting the angles of the X-direction mirror and the Y-direction mirror of the two-dimensional galvanometer scanning system 402 . The computer processing terminal 600 transmits data signals to the two-dimensional galvanometer scanning system 402 through the data acquisition card.

As a further preferred embodiment, the image acquisition module 505 is a line array CCD camera.

As a further preferred embodiment, the light source 100 is a light emitting diode with a wavelength of 1310 nm. Because the absorption coefficient of light in this band of 1310nm is relatively small in skin tissue, the scattering coefficient is relatively high, which is suitable for skin imaging.

Referring to FIG. 3 , the ultra-wide-range skin imaging device further includes an ultra-wide-range skin imaging method, and the method includes:

The light beam emitted by the light source 100 is divided into a first beam and a second beam by the fiber coupler 200, the first beam enters the first collimating lens 301, and the second beam enters the second collimating lens 401;

After the first beam passes through the first collimating lens 301, under the action of the mirror 302, it returns to the fiber coupler 200 in the same way; the exit light of the second beam after passing through the second collimating lens 401 enters the two-dimensional galvanometer for scanning System 402, the two-dimensional galvanometer scanning system 402 is used to adjust the direction of the light beam, and the outgoing light of the two-dimensional galvanometer scanning system 402 passes through the first focusing lens 403 and then scans the skin to be tested 700 along a preset scanning path. Scanning, the scanned light beam is scattered on the surface of the skin to be tested 700, and the scattered light enters the fiber coupler 200 through the first focusing lens 403, the two-dimensional galvanometer scanning system 402 and the second collimating lens 401 in sequence;

The first light beam returning to the fiber coupler 200 interferes with the scattered light to generate an interference light signal, the interference light signal includes the image information of the skin 700 to be tested, and the fiber coupler 200 outputs the interference light signal to the third The collimating lens 501 is used for collimation, the light emitted from the third collimating lens 501 passes through the grating 502 and the triangular prism 503 for beam splitting in sequence, and the interference light signal after splitting passes through the second focusing lens 504 and then enters the image acquisition module 505;

The two-dimensional galvanometer scanning system 402 is used to adjust the direction of the light beam. The two-dimensional galvanometer scanning system 402 is composed of an X-direction mirror and a Y-direction mirror, and performs scanning in the X-direction and Y-direction respectively. The direction represents the horizontal scan, and the Y direction represents the vertical scan. When the scanning in the Y direction is 0, two-dimensional scanning, that is, cross-sectional imaging, is realized; when the scanning in the Y direction is not 0, three-dimensional scanning is realized, that is, three-dimensional imaging is realized. The two-dimensional galvanometer scanning system 402 is electrically connected to the computer processing terminal 600, and the computer processing terminal 600 controls the two-dimensional galvanometer scanning system 402 to adjust the scanning speed and scanning path of the light beam.

Referring to FIG. 2 for the preset scanning path, in the process of scanning and imaging, the imaging size of 2*2mm is used as the primitive, and the skin to be tested 700 is scanned sequentially in the S-shaped scanning sequence, and 2*2mm is used as the primitive. The adjacent scanning areas of 100 have overlapping parts. After completing the preset scanning path, the scanning signals of multiple scanning areas are acquired. The image acquisition module 505 collects the interference light signals including the scanning signals of these scanning areas, and the interference The optical signal is sent to the computer processing terminal 600 .

Fourier transform and background denoising are performed on the interference light signal to obtain denoised images of multiple scanning areas during the scanning process;

Using a phase compensation algorithm to eliminate motion artifacts on the denoised image to obtain a de-artifacted image;

The two-dimensional cross-correlation algorithm is used to calibrate and match the de-artifacted images, and then the SURF-based image stitching algorithm is used to stitch the calibrated and matched de-artifact images to obtain an imaging image.

Further as a preferred embodiment, the process of performing Fourier transform and background denoising on the interference optical signal includes:

Collecting the optical signal of the first light beam returning to the fiber coupler 200 as a background signal, performing Fourier transform on the interference optical signal to obtain a block scanning image, subtracting the background signal from the block scanning image to obtain a denoised image, and eliminating the The influence of the background signal on the final imaged image of the skin to be tested 700 .

In the process of scanning the skin 700 to be tested, the movement of human tissue inevitably occurs. In order to eliminate the motion artifact caused by the autonomous motion of the human body in the blood imaging, the present embodiment extracts the motion artifact through the histogram compensation map in the phase compensation algorithm. and remove motion artifacts.

Further as a preferred embodiment, the process of using a phase compensation algorithm to eliminate motion artifacts on the de-noised image, and obtaining the de-artifact image includes:

A histogram calculation is performed on the phase of the denoised image, and the principle of the width of the histogram is:

h=2IQm ^-1/3

Where h is the width of the histogram, IQ is the interquartile difference of the phase arrangement, and m is the total number of phases;

The most frequently occurring phase values are obtained from the histograms of adjacent denoised images. These phase values constitute the motion artifact phase. The motion artifact phases are extracted from the histograms of adjacent denoised images. The phase of the histogram of the denoised image is subtracted from the phase of the motion artifact to obtain the de-artifacted image.

Further as a preferred embodiment, the process of performing image calibration and matching using a two-dimensional cross-correlation algorithm on the de-artifacted image includes:

The two-dimensional cross-correlation algorithm is used to calculate the image offset between two adjacent de-artifacted images, and the correlation between the two adjacent de-artifacted images can be expressed as:

Among them, f ₁ (x ₁ , y ₁ ), f ₂ (x ₂ , y ₂ ) are the functions of two adjacent de-artifact images respectively, Δx is the offset in the lateral direction, and Δy is the axial direction Offset on , calibrates the motion offset between two adjacent de-artifacted images for image matching. According to the calculated motion offset between the two de-artifacted images, if the motion offset is negative, add the motion offset for image matching; if the motion offset is positive, subtract the motion offset Shift amount for image matching.

After the adjacent de-artifacted images are matched, the SURF-based image stitching algorithm is used to stitch the calibrated and matched de-artifact images to obtain an imaging image.

Image stitching is an image stitching algorithm based on SURF. First, input two adjacent de-artifact images with overlapping areas. The width of the overlapping area is preferably 0.1-0.3 mm. In this embodiment, the computer processing terminal 600 is used to adjust the scanning of the skin to be tested 700 by the two-dimensional galvanometer scanning system 402 speed and scanning distance, so that the width of the overlapping area between adjacent de-artifacted images is 0.1mm, and the adjacent de-artifacted images are calibrated and matched by using two-dimensional cross-correlation algorithm, and then matched by SURF feature After the algorithm extracts the image feature points of the overlapping area between the adjacent de-artifacted images, the feature points of the adjacent de-artifacted images are fused, and the adjacent de-artifacted images are mapped to a new blank image to form The images are stitched together to get the final image.

Perform image feature point recognition and fusion in the overlapping area of the SURF-based image stitching algorithm on all the collected de-artifact images, and map the fused de-artifact images to a new blank image to form a stitched image, and obtain the desired image. The imaging image of the skin 700 to be measured is obtained, so that an ultra-wide scanning atmosphere of the skin 700 to be measured is effectively obtained.

In this embodiment, the width of the overlapping area between adjacent de-artifacted images is 0.1 mm, which can ensure the continuity of image stitching.

The skin imaging device of the present invention performs real-time large-scale imaging of the skin to be tested 700, increases the imaging range in the depth direction by improving the spectral resolution of the spectrometer device 500, and obtains a large-scale imaging image through an image stitching algorithm.

The preferred embodiments of the present utility model have been specifically described above, but the invention of the present utility model is not limited to the described embodiments, and those skilled in the art can make various equivalent modifications without departing from the spirit of the present utility model. Or alternatives, these equivalent modifications or alternatives are included within the scope defined by the claims of the present application.

Claims (5)

1. an ultra-wide range of skin imaging equipment, is characterized in that, comprising: light source, optical fiber coupler, reference arm device, sample arm device, spectrometer device and computer processing terminal; The first collimation that described reference arm device comprises a lens and a reflector, the first collimating lens and the reflector are connected by light; The sample arm device includes a second collimating lens, a two-dimensional galvanometer scanning system and a first focusing lens. The light emitted from the second collimating lens is deflected by the two-dimensional galvanometer scanning system and then enters the first focusing lens. The outgoing light of a focusing lens enters the skin to be tested; The spectrometer device includes a third collimating lens, a grating, a triangular prism, a second focusing lens, and an image acquisition module connected by light rays. The light emitted from the third collimating lens passes through the grating and the triangular prism in sequence, and the output of the triangular prism is The incident light enters the image acquisition module after passing through the second focusing lens; The light source, the first collimating lens, the second collimating lens and the third collimating lens are all connected with the optical fiber coupler through optical fibers, and the image acquisition module and the two-dimensional galvanometer scanning system are processed with the computer Terminal electrical connection. 2 . The ultra-wide range skin imaging device according to claim 1 , wherein the two-dimensional galvanometer scanning system is connected to the computer processing terminal through a data acquisition card. 3 . 3 . The ultra-wide-range skin imaging device according to claim 1 , wherein the image acquisition module is connected to the computer processing terminal through an image acquisition card. 4 . 4 . The ultra-wide range skin imaging device according to claim 1 , wherein the image acquisition module is a line array CCD camera. 5 . 5 . The ultra-wide-range skin imaging device according to claim 1 , wherein the light source is a light-emitting diode with a wavelength of 1310 nm. 6 .

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