CN216777062U

CN216777062U - Rapid imaging system for human skin laser speckle blood flow

Info

Publication number: CN216777062U
Application number: CN202123251610.3U
Authority: CN
Inventors: 陈相柏; 候华毅; 杜功志; 黄斌
Original assignee: Wuhan Gepu Photoelectric Technology Co ltd
Current assignee: Wuhan Gepu Photoelectric Technology Co ltd
Priority date: 2021-12-23
Filing date: 2021-12-23
Publication date: 2022-06-21
Anticipated expiration: 2031-12-23

Abstract

The utility model relates to a medical treatment detection area, concretely relates to quick imaging system of human skin laser speckle blood flow, this system includes the laser instrument, laser beam expanding device, the speculum, the analyzer, filter, the image acquisition module, laser rangefinder module, the laser positioning module, a computer, the laser instrument, laser beam expanding device, the speculum is located the illumination light road in proper order, human skin reflection illumination light, human skin, the analyzer, filter, the image acquisition module is located the formation of image light path in proper order, the computer respectively with the image acquisition module, laser rangefinder module, the laser positioning module links to each other. Compared with the prior art, the method can accurately determine the position of the skin to be detected and the distance between the skin to be detected and the image acquisition module, and the acquired image is convenient for data processing; the upper computer graphic system is convenient for operators to clearly and completely check the blood flow state of the detected skin, and great convenience is brought to the use of users.

Description

Rapid imaging system for human skin laser speckle blood flow

Technical Field

The utility model relates to the field of medical detection, in particular to a rapid imaging system for human skin laser speckle blood flow.

Background

The skin circulation state is a major indicator of vascular access, functional level, and characterization of cardiovascular disease. The skin blood perfusion is defined as the amount of blood flowing through the skin in a unit time, and is one of important indexes in the processes of human microcirculation monitoring, health diagnosis, prognosis evaluation and the like.

The laser speckle blood flow imaging technology has the advantages of no wound, large visual field, rapid real-time monitoring and the like, can realize large-area monitoring of skin blood flow, can obtain blood flow velocity distribution, and has a plurality of applications in the field of biomedical photon imaging, such as blood flow imaging of animal cerebral cortex, viscera, eye ground, retina, auricle, skin and the like, further promotes the research of biomedical, and has skin burn recovery monitoring, pathological diagnosis of diabetic complication diabetic foot, tissue diastolic blood flow monitoring and the like for human body application.

In the prior art, the cross-sectional size of an illuminating beam is small, and the light intensity in an illuminating area is uneven, so that the image brightness or light intensity spatial distribution gradient is large in laser speckle imaging, and the error is large in image processing. In addition, it is difficult for the image pickup apparatus to determine the pickup area in practical use.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems, the utility model provides a rapid imaging system for human skin laser speckle blood flow on one hand, which comprises a laser, a laser beam expanding device, a reflecting mirror, an analyzer, a filter device, an image acquisition module, a laser ranging module, a laser positioning module and a computer, wherein the laser, the laser beam expanding device and the reflecting mirror are sequentially positioned on an illumination light path, the human skin reflects the illumination light, the human skin, the analyzer, the filter device and the image acquisition module are sequentially positioned on an imaging light path, the laser ranging module and the laser positioning module emit laser, the laser is reflected by the human skin and then re-enters the laser ranging module and the laser positioning module respectively, and the computer is respectively connected with the image acquisition module, the laser ranging module and the laser positioning module.

Furthermore, the wavelength of the laser ranging module is 633 nm.

Further, the laser is a semiconductor laser.

Furthermore, the imaging light path is parallel to the light path of the laser emitted by the laser ranging module and the laser positioning module.

Furthermore, the laser beam expanding device comprises a plano-concave lens and a plano-convex lens, and the plano-concave lens is close to one side of the laser.

Furthermore, the laser device also comprises a linear polarizer, and the linear polarizer is positioned between the laser and the laser beam expanding device on the illumination light path.

On the other hand, the utility model also provides a use method of the human skin laser speckle blood flow rapid imaging system, which comprises the following steps:

step 1, determining the distance from an image acquisition module to skin by using a laser ranging module and a laser positioning module, and positioning a skin area of a human body;

step 2, irradiating the laser beam to a region to be detected of human skin;

step 3, collecting the image of the area to be detected through an image collecting module, wherein the number of the collected image frames is N;

step 4, calculating the contrast K (x, y) by a calculation formula (I),

where K (x, y) is the contrast value at the (x, y) pixel, I_x,y(n) is the intensity of light at (x, y) pixel coordinates in the nth image,

is the average of the intensity of the N images at (x, y);

step 5, calculating the blood flow velocity v (x, y) c/K by using the contrast²(x, y), wherein c is a correction factor.

Further, in step 3, the number of frames N is equal to 10.

Further, in step 4, the area where the contrast K (x, y) is calculated is larger than the area irradiated with the laser beam.

The utility model has the beneficial effects that: the utility model provides a rapid imaging system for human skin laser speckle blood flow, which comprises a laser, a laser beam expanding device, a reflecting mirror, an analyzer, a light filtering device, an image acquisition module, a laser distance measurement module, a laser positioning module and a computer, wherein the laser, the laser beam expanding device and the reflecting mirror are sequentially positioned on an illumination light path, the human skin reflects illumination light, the human skin, the analyzer, the light filtering device and the image acquisition module are sequentially positioned on an imaging light path, the laser distance measurement module and the laser positioning module emit laser, the laser enters the laser distance measurement module and the laser positioning module again after being reflected by the human skin, and the computer is respectively connected with the image acquisition module, the laser distance measurement module and the laser positioning module. Compared with the prior art, the skin positioning device comprises the laser ranging module and the laser positioning module, the position of the skin to be measured and the distance between the skin to be measured and the image acquisition module can be accurately determined, and the acquired image is convenient for data processing; the upper computer graphic system can display the original image of the detected area in the whole process and acquire and process the back image, so that an operator can clearly and completely check the blood flow state of the detected skin, and great convenience is brought to the user.

The present invention will be described in further detail below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of the rapid imaging system for laser speckle blood flow of human skin according to the present invention.

Fig. 2 is a schematic diagram of a laser beam expanding device.

In the figure: 1. a laser; 2. a laser beam expanding device; 3. a mirror; 4. human skin; 5. an analyzer; 6. a light filtering means; 7. an image acquisition module; 8. a laser ranging module; 9. a laser positioning module; 10. and (4) a computer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below by referring to the accompanying drawings and examples.

Example 1

The utility model provides a rapid imaging system for laser speckle blood flow of human skin, which comprises a laser 1, a laser beam expanding device 2, a reflector 3, an analyzer 5, a filtering device 6, an image acquisition module 7, a laser ranging module 8, a laser positioning module 9 and a computer 10, as shown in figure 1. The laser 1 is a helium-neon laser or a semiconductor laser. Preferably, the laser 1 is a semiconductor laser. The analyzer 5 is a polarizer. The filter means 6 is a filter. The image acquisition module 7 comprises a photoelectric imaging device. The laser 1, the laser beam expanding device 2 and the reflector 3 are sequentially positioned on an illumination light path. As shown in fig. 2, the laser beam expander 2 is a galilean beam expanding structure, and the laser beam expander 2 includes a plano-concave lens and a plano-convex lens, and the plano-concave lens is close to one side of the laser 1. After passing through the laser beam expanding device 2, the laser facula is enlarged, the area of irradiating the human skin 4 is increased, and when the image is collected, the uniform irradiation area can be collected, the difference between adjacent pixels is small, and the error is small during the subsequent processing. The human skin 4 reflects the illumination light. The human skin 4, the analyzer 5, the filter 6 and the image acquisition module 7 are sequentially positioned on the imaging light path. The image acquisition module 7 comprises a photoelectric imaging device. The photoelectric imaging device is an area array digital CCD camera or a CCD video camera or a CMOS video camera. The optical filter is positioned on the imaging light path and between the human skin 4 and the photoelectric imaging device; the analyzer 5 is positioned between the optical filter and the photoelectric imaging device on the imaging optical path. Laser ranging module 8 and laser positioning module 9 send laser, reentrant laser ranging module 8 and laser positioning module 9 respectively after human skin 4 reflects. The wavelength of the laser ranging module 8 is 633 nanometers. The imaging light path is parallel to the light path of the laser emitted by the laser ranging module 8, so that the distance between the human skin 4 and the imaging device in the image acquisition module 7 can be measured accurately. The laser positioning module 9 is used for marking the specific position of imaging, and can determine the human skin 4 to collect the region to be detected. The laser ranging module 8 measures the distance from the photoelectric imaging device to the human skin 4 to be measured in the image acquisition module 7, and is used for adjusting optical parameters of the photoelectric imaging device, such as the focal length of a CCD camera, and the like, so that the acquired laser speckle image is clearer. The wavelength of the laser ranging module is 950 nanometers. The computer 10 is respectively connected with the image acquisition module 7, the laser ranging module 8 and the laser positioning module 9. The computer 10 forms an upper computer, the image acquisition module 7 acquires an original laser speckle blood flow image and transmits the image to the upper computer, and the upper computer programs a set of graphical software system of a real-time space-time combined algorithm and an algorithm for calculating blood flow perfusion. In addition, the computer 10 is connected to a display device for displaying the parameter information acquired by the computer 10 or calculated according to the preset logic, wherein the parameter information includes image information, curve information and data information. The upper computer graphical system can display the original image of the detected area and the processed image in the whole course, so that the operator can clearly and completely check the blood flow state of the skin 4 of the detected human body, and the use of the user is greatly facilitated. Furthermore, a linear polarizer is included, and the linear polarizer is positioned between the laser 1 and the laser beam expanding device 2 on the illumination light path.

In the utility model, light emitted by a laser 1 is expanded by a laser beam expanding device 2 and then irradiates on human skin 4 of a measured object by a reflector 3, the human skin 4 is scattered, a speckle image is formed by an image acquisition module 7 and is transmitted into a computer 10, and the computer 10 calculates the relative blood flow velocity by adopting a space-time joint algorithm and forms a distribution graph. The blood flow speed is monitored in real time by adopting a laser speckle blood flow detection method, the blood vessel condition and the blood supply circulation condition can be judged through the blood flow speed change at different stages, and the blood flow state of microcirculation can be observed in real time; in addition, the utility model provides a beam expander designed by a Galileo beam expanding structure, expands a laser light path, and combines a reflector 3, a filter 6 and an analyzer 5 to enable the light path structure to be adjustable and simple; in addition, a set of laser ranging module 8 with the wavelength of 633nm and a laser positioning module 9 are designed to adjust relevant parameters of the image acquisition module 7 and position specific imaging positions, so that the imaging performance of the device is improved, and subsequent image calculation is facilitated.

Example 2

The utility model also provides a use method of the human skin laser speckle blood flow rapid imaging system, which comprises the following steps:

step 1, determining the distance from an image acquisition module 7 to human skin 4 and positioning the human skin 4 area by using a laser ranging module 8 and a laser positioning module 9;

step 2, irradiating the laser beam to the area to be measured of the human skin 4;

step 3, collecting images of the area to be detected through an image collecting module, wherein the number of the collected images is N, and the number of the collected images is equal to 10;

step 4, calculating the contrast K (x, y) by a calculation formula (I),

is the average value of the light intensity of the N images at (x, y), and the area for calculating the contrast K (x, y) is larger than the area irradiated by the laser beam. The area where the calculated contrast is larger than the area irradiated by the laser beam ensures that the calculated contrast contains the region of interest, from which the region of interest is then extracted.

Is the average value of the light intensity of the N images at (x, y), and refers to the average value of the light intensity at (x, y) in different frames.

Step 5, calculating the blood flow velocity v (x, y) c/K by using the contrast²(x, y), wherein c is a correction factor. In addition, the blood flow velocity is proportional toWhile speed is proportional to T/tau_cWhere T is the exposure time of the charge coupler, τ_cIs the autocorrelation time.

The method for calculating the contrast by adopting the space-time joint algorithm comprises the steps of taking a plurality of collected original laser speckle images, obtaining light intensity values of a series of pixel points in the original speckle images in time and space dimensions, calculating the contrast value, and then obtaining the relative blood flow velocity distribution.

In the prior art, the method adopted when measuring the laser speckle blood perfusion volume is complex and difficult to realize. The laser speckle blood perfusion measuring method provided by the utility model is simple and easy to realize, can be used for acquiring the blood flow velocity distribution of the blood perfusion of the human skin 4, and has the advantages of comprehensively and real-timely measuring and representing the skin tissue to be measured.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. The utility model provides a quick imaging system of human skin laser speckle blood flow, its characterized in that, includes laser instrument, laser beam expanding device, speculum, analyzer, filter, image acquisition module, laser rangefinder module, laser positioning module, computer, the laser instrument laser beam expanding device the speculum is located illumination light path in proper order, and human skin reflection illumination light, human skin the analyzer light filter the image acquisition module is located imaging light path in proper order, laser rangefinder module with laser positioning module sends laser, gets into again respectively after human skin reflection laser rangefinder module with laser positioning module, the computer respectively with the image acquisition module laser rangefinder module the laser positioning module links to each other.

2. The rapid imaging system of human skin laser speckle blood flow of claim 1, wherein: the wavelength of the laser ranging module is 633 nanometers.

3. The rapid imaging system of human skin laser speckle blood flow of claim 2, wherein: the laser is a semiconductor laser.

4. The rapid imaging system of human skin laser speckle blood flow of claim 3, wherein: the imaging light path is parallel to the light path of the laser emitted by the laser ranging module.

5. The rapid imaging system of human skin laser speckle blood flow of claim 4, wherein: the laser beam expanding device comprises a plano-concave lens and a plano-convex lens, wherein the plano-concave lens is close to one side of the laser.

6. The rapid imaging system of human skin laser speckle blood flow of claim 5, wherein: the linear polarizer is positioned between the laser and the laser beam expanding device on the illumination light path.

7. The rapid imaging system of human skin laser speckle blood flow of any one of claims 1 to 6, wherein: the distance from the image acquisition module to the skin is determined through the laser ranging module and the laser positioning module.

8. The rapid imaging system of human skin laser speckle blood flow of claim 7, wherein: the image acquisition module acquires images of an area to be detected, and the number of the acquired images is 10.