A near-infrared blood vessel imaging method and apparatus

Abstract

The present application relates to the technical field of medical devices, in particular to a near-infrared blood vessel imaging method and device, wherein the near-infrared blood vessel imaging method comprises the following steps: dividing a skin surface blood vessel detection area into multiple detection units, using two parallel linear near-infrared light beams to irradiate the edges of the detection units one by one, and performing follow-up shooting to generate a near-infrared image, and generating a visible image of the entire detection area according to the near-infrared image, the imaging method adopted by the present application is different from conventional large-area detection, can significantly reduce the influence of skin surface reflected light generated by illumination light irradiation, improve the contrast of the blood vessel image, has high detection precision, can discover deep blood vessels, is more suitable for obese patients, and by using the visible light projection mode to re-irradiate the detection area, it is convenient for medical staff to find the blood vessels of the patient, and has progressiveness.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a near-infrared vascular imaging method and apparatus. Background Technology

[0002] Because near-infrared light (wavelength 700nm-1100nm) penetrates deeper into human tissues than visible light, and because hemoglobin in venous blood absorbs near-infrared light energy significantly more than perivascular tissues such as fat and melanin, near-infrared imaging can significantly improve the contrast between veins and surrounding tissues. This contrast is reflected in the captured image as a difference between light and dark areas, with the darker areas representing the locations of blood vessels that absorb near-infrared light, thus obtaining a clearer image of the vascular structure.

[0003] Currently, vein visualization imaging devices developed based on this principle have been gradually applied to clinical medicine. However, most devices still use the method of covering the target with near-infrared light and then taking pictures with a camera. When the illumination light is incident on the skin tissue, it will produce reflected light, which will also be captured by the camera. The reflected light does not contain subcutaneous blood vessel information and is considered interference noise. Therefore, it is impossible to improve the image effect simply by increasing the near-infrared light intensity. For deep blood vessels, the imaging on the skin (i.e., the difference between light and dark) is very weak. Under the interference of skin reflected light, it is difficult to accurately identify them through camera imaging.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a near-infrared vascular imaging method and device, which has the characteristics of accurate vascular identification and clear observation effect.

[0006] To achieve the above objectives, this invention discloses a near-infrared vascular imaging method, comprising the following steps:

[0007] The skin surface blood vessel detection area is divided into multiple detection units;

[0008] Two parallel linear near-infrared beams are used to illuminate the edge of the detection unit one by one and follow it to capture images, generating near-infrared images.

[0009] A visual image of the entire detection area is generated based on the near-infrared image.

[0010] It should be noted that the technical approach of this invention is to subdivide the detection area into multiple detection units, and to sample each of these detection units individually. Specifically, when sampling a certain detection unit, a near-infrared beam is used to illuminate the two sides of the detection unit. After the strong beam enters the skin, such as... Figure 1 and 2 As shown, the incident point is at point A in the diagram. The light will scatter in various directions, including forward scattering into the deeper skin tissue and backward scattering onto the skin surface. When the incident beam scatters directly below the detection unit, if there are blood vessels present, the hemoglobin in the blood will strongly absorb the near-infrared light, weakening the backscattered light and creating a "dark area" at the detection unit on the skin surface. Figure 1 At point B, if there are no blood vessels, backscattering is normal, creating a relatively "bright area" on the skin surface caused by diffused light. Figure 2 At point B, after the camera captures the brightness and darkness features of each detection unit, all detection units are combined according to their spatial positions to obtain the overall brightness and darkness features of the entire detection area. The darkness features represent the presence of blood vessels, thus locating the blood vessels and assisting medical staff in finding the patient's veins. Because the above method irradiates the edges on both sides of the detection unit and the irradiation width is very narrow, while the area acquired is the area of ​​each detection unit, the irradiation area and the acquisition area do not overlap, thus preventing interference from reflected light from the skin surface and superficial layers, improving the brightness and darkness contrast of the blood vessel image, making the blood vessels more clearly visible in the image, and thus discovering deeper veins.

[0011] Furthermore, the visible light image is projected onto the original detection area in a 1:1 overlap manner.

[0012] This should be understood as projecting the detected infrared image back onto the detection area using visible light, ensuring that the visible light image and the detected infrared image overlap 1:1, facilitating direct observation and operation by medical staff, or outputting the image onto an electronic screen.

[0013] Furthermore, a reflector is used to reflect two linear near-infrared beams and the optical path of the near-infrared imaging lens to the detection unit. By repeatedly oscillating the reflector, the multiple detection units can be illuminated and photographed.

[0014] A superior implementation method is proposed here. In order to obtain two linear near-infrared beams and illuminate the detection units one by one, a reflector is selected to reflect the two linear near-infrared beams and the optical path of the near-infrared imaging lens to the detection units. By swinging step by step, the two linear near-infrared beams illuminate the edges of different detection units. Moreover, during the swinging process, the optical path of the imaging lens also follows the movement, thereby completing the imaging process of different detection units.

[0015] Furthermore, a near-infrared beam with a rectangular cross-section is incident on the micro-mirror array, and two parallel galvanometers in the micro-mirror array are controlled in sequence to generate two linear near-infrared beams that move in a directional manner.

[0016] Another superior implementation method is proposed here: the two parallel row mirrors in the micro-mirror array are turned on one by one to obtain two linear near-infrared beams at different positions, thereby illuminating the edges of different detection units.

[0017] The present invention also discloses a near-infrared vascular imaging device, comprising:

[0018] The illumination module includes a near-infrared beam generator and a light rectifier. The near-infrared beam generator is used to emit near-infrared light, and the light rectifier uses the near-infrared light to generate two directional, linear near-infrared beams.

[0019] Near-infrared imaging module, used to capture and generate near-infrared images;

[0020] The calculation and control module calculates and integrates multiple near-infrared images into an image signal with vascular information;

[0021] The projection module converts the image signal into a visible light image;

[0022] A beam splitter is used to transmit near-infrared light and reflect visible light images onto the shooting area.

[0023] Furthermore, the light rectifier includes a reflector and a stepper motor. The reflector is located above the beam splitter, and the stepper motor drives the reflector to swing back and forth.

[0024] Furthermore, the rotation angle of the reflector is calculated using the following formula:

[0025]

[0026] Where ω is the rotation angle, h is the height of the detection area perpendicular to the field of view of the linear array camera, d is the distance between the two near-infrared laser beams on the detection surface, l is the distance from the reflector to the detection area, and θ is the reserved angle.

[0027] It needs to be explained that in order to ensure that the overall two-dimensional vascular image is not distorted when the images captured by the linear scan camera are integrated according to the scanning direction, the rotation speed of the reflector needs to remain constant during shooting. That is, the stepper motor needs to accelerate to a constant speed within the reserved angle.

[0028] Furthermore, the infrared beam generator includes an upper near-infrared beam generator and a lower near-infrared beam generator, both of which emit near-infrared laser beams with a linear cross-section. The near-infrared imaging module is a line-scan camera. The upper and lower near-infrared beam generators are respectively fixed on the upper and lower sides of the line-scan camera. The rotation axis of the reflector is located on the center line of the optical path directly in front of the infrared camera.

[0029] Furthermore, the light rectifier is a micro-mirror array, which is controlled by a logic circuit. The near-infrared beam generator is installed on one side of the micro-mirror array, and an absorption screen is provided on the other side of the micro-mirror array.

[0030] Furthermore, a 45° inclined reflector is provided above the beam splitter, so that the infrared light reflected back from the detection area is reflected a second time by the beam splitter into the imaging optical path of the near-infrared imaging module.

[0031] Furthermore, it also includes a housing, in which the irradiation module, the near-infrared imaging module, the calculation and control module, the projection module and the beam splitter are all installed, and a light-transmitting hole is provided at the bottom of the housing.

[0032] Furthermore, the beam splitter is tilted at 45°.

[0033] Furthermore, a light-transmitting glass lens is provided over the light-transmitting hole.

[0034] Furthermore, a power module is provided on the back of the housing, and the power module is a rechargeable rectangular battery or a power housing with a battery inside.

[0035] Furthermore, a bracket is provided below the power module, which is a handheld stand or a base with a column.

[0036] Furthermore, the column is a telescopic column.

[0037] Furthermore, when the bracket is a base with a column, the base is provided with an arc-shaped groove.

[0038] The beneficial effects of this invention are as follows: The near-infrared vascular imaging method and apparatus provided by this invention divide a large area of ​​the skin surface vascular detection region into multiple detection units. Two parallel linear near-infrared beams are used to irradiate the edges of each detection unit one by one and follow the image to generate a near-infrared image. The imaging of each detection unit is different from conventional large-area detection. It can significantly reduce the influence of direct illumination on the skin surface, improve the contrast of vascular information in the image, and can detect deep vascular vessels. It is more suitable for obese patients. By using visible light projection to re-irradiate the detection area, it is easier for medical staff to find the patient's blood vessels, which is an improvement. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 The principle of the near-infrared vascular imaging method in this invention Figure 1 ;

[0041] Figure 2 The principle of the near-infrared vascular imaging method in this invention Figure 2 ;

[0042] Figure 3 This is a schematic diagram of the near-infrared vascular imaging device in Embodiment 1 of the present invention;

[0043] Figure 4 This is a schematic diagram of the near-infrared vascular imaging device (partial shell omitted) in Embodiment 1 of the present invention;

[0044] Figure 5 This is a front view of the near-infrared vascular imaging device (partial housing omitted) in Embodiment 1 of the present invention;

[0045] Figure 6 This is a schematic diagram of the near-infrared vascular imaging device (partial shell omitted) from another perspective in Embodiment 1 of the present invention;

[0046] Figure 7 for Figure 6 Enlarged view of point A in the middle;

[0047] Figure 8 This is a near-infrared beam reflection diagram of the reflector at the first angle in Embodiment 1 of the present invention;

[0048] Figure 9This is a near-infrared beam reflection diagram of the mirror at the second angle in Embodiment 1 of the present invention;

[0049] Figure 10 This is a schematic diagram illustrating the near-infrared beam irradiation area and the visible light irradiation area in Embodiment 1 of the present invention;

[0050] Figure 11 This is a structural diagram of the near-infrared vascular imaging device (partial housing omitted) in Embodiment 2 of the present invention;

[0051] Figure 12 for Figure 11 Enlarged view at point B in the middle;

[0052] Figure 13 This is a front view of the near-infrared vascular imaging device (partial housing omitted) in Embodiment 2 of the present invention;

[0053] Figure 14 This is a schematic diagram of near-infrared light beam irradiating the micro-mirror array in Embodiment 2 of the present invention;

[0054] Figure 15 This is a schematic diagram of the near-infrared beam being reflected onto the near-infrared imaging module in Embodiment 2 of the present invention;

[0055] Figure 16 This is a schematic diagram of another state in which the near-infrared beam is reflected to the near-infrared imaging module in Embodiment 2 of the present invention.

[0056] Reference numerals: 1. Near-infrared beam generator; 2. Calculation and control module; 3. Projection module; 4. Beam splitter; 5. Reflector; 6. Stepper motor; 7. Near-infrared imaging module; 8. Micro-mirror array; 9. Housing; 10. Transparent glass lens; 11. Power module; 12. Column; 13. Base; 14. Arc-shaped groove; 15. Absorption screen. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0058] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0060] Example 1

[0061] like Figures 3 to 10 A near-infrared vascular imaging device is shown, comprising: a housing 9 and an irradiation module, a near-infrared imaging module 7, a calculation and control module 2, a projection module 3 and a beam splitter 4 located within the housing 9, with a light-transmitting hole provided at the bottom of the housing 9.

[0062] like Figure 4-7 As shown, the irradiation module includes two near-infrared laser beam generators 1 and a light rectifier. The near-infrared laser beam generators 1 emit near-infrared laser beams with a linear cross-section. This linear cross-section near-infrared laser beam can be achieved by using a shaper with a rectangular through-hole to constrain the near-infrared laser beam. Since the near-infrared laser beam generators 1 and the near-infrared imaging module 7 are relatively large, and to obtain two near-infrared laser beams with a smaller interval, the two near-infrared laser beam generators 1 need to be installed at an angle so that the beams emitted forward gradually approach each other. In this embodiment, the light rectifier specifically consists of a reflector 5 and a stepper motor 6. The reflector 5 and the stepper motor 6 are located directly above the light-transmitting hole. The reflector 5 is driven by the stepper motor 6 to reciprocate within a certain angle range. Figure 8 and Figure 9 As can be seen, the reflector 5 reflects the two near-infrared beams emitted by the two near-infrared laser beam generators 1 downwards. Driven by the stepper motor 6, the reflector 5 oscillates back and forth within a certain angle range, causing the two parallel linear near-infrared beams to sweep across the target. Simultaneously, the near-infrared imaging module 7 captures images of the area between the two near-infrared beams, i.e., the position of each detection unit, generating row images. One sweep cycle yields two sets of row images. The row images are arranged in sequence to form a planar image. The images obtained when the reflector 5 oscillates counterclockwise are arranged in positive column order, and the images obtained when the reflector 5 oscillates clockwise are arranged in positive column order. The images are arranged in reverse column order, thus transforming the line image into a planar image of the entire detection area. To facilitate the calculation of the swing angle, the rotation axis of the reflector 5 is located on the center line of the optical path directly in front of the near-infrared imaging module 7. The swing amplitude of the reflector 5 is controlled by the stepper motor 6. The start and end positions of the row images can be determined by the trigger signal provided by the stepper motor 6. Alternatively, photoelectric sensors can be set at the upper and lower edges of the reflector 5. When the reflector 5 moves to the start or stop position, an action signal is generated. The row images between the two action signals are arranged to form the captured image of the entire detection area.

[0063] The near-infrared imaging module 7 specifically adopts a line scan camera, or the shaper mentioned above can be used to constrain the lens of an ordinary camera to form a rectangular light acquisition path. The line scan camera and the two near-infrared laser beam generators 1 are both installed in the upper left corner of the housing 9.

[0064] The computing and control module 2, specifically equipped with a microprocessor and a switch, is used to calculate and synthesize an image signal with vascular information from all the near-infrared images of the detection area completed in one go, and then send it to the projection module 3. At the same time, the computing and control module 2 is connected to the irradiation module, the near-infrared imaging module 7, the projection module 3 and the stepper motor 6 respectively, and is used to control the normal operation of the entire device.

[0065] Projection module 3, specifically a projector, is located in the lower right corner inside housing 9. It converts the image signal sent by calculation and control module 2 into a visible light image and projects it out. Figure 10 As can be seen, the projected visible light image covers the original detection area;

[0066] Beam splitter 4, used for transmitting near-infrared light and reflecting visible light, is located directly above the light-transmitting aperture and in the optical path directly in front of the projector. Figure 8-10 As can be seen, the near-infrared laser beam reflected by the reflector 5 passes directly downward through the beam splitter 4, while the visible light emitted by the projection module 3 is refracted by the beam splitter 4 and illuminates the surface of the human tissue below. By setting the beam splitter 4, visible light is prevented from being reflected back into the linear array camera, thus improving the accuracy of recognition.

[0067] To facilitate projection, beam splitter 4 is tilted at 45°, at which point the projector can illuminate horizontally.

[0068] like Figure 4 As shown, in order to prevent dust from entering the interior of the housing 9, a light-transmitting glass lens 10 is provided at the light-transmitting hole.

[0069] like Figure 3 As shown, as a specific disclosure of the above embodiment, a power module 11 is provided on the back of the housing 9. The power module 11 is a rechargeable rectangular battery or a power housing 9 with a battery inside.

[0070] To facilitate placement of the device on the patient's skin by medical staff, a bracket is provided below the power module 11. This bracket can be a handheld base, allowing medical staff to simply hold it in their hand during use. Figure 3 As shown, it may be a base 13 with a column 12, and the column 12 may be designed as a telescopic column 12 for easy focusing.

[0071] As a preferred embodiment of the above, such as Figure 3 As shown, when the bracket is a base 13 with a column 12, an arc-shaped groove 14 is provided on the base 13, which makes it convenient for the patient to place their arm on the base 13.

[0072] Example 2

[0073] like Figures 11 to 16 Another near-infrared vascular imaging device is shown. Unlike Embodiment 1, this embodiment uses a different type of light rectifier. Specifically, the light rectifier is a micromirror array 8, which is controlled by logic circuitry. A near-infrared laser beam generator 1 is mounted on one side of the micromirror array 8, and an absorption screen 15 is provided on the other side. In specific use, as follows... Figure 14 As shown, the near-infrared laser beam generator 1 is tilted and mounted on one side of the micro-mirror array 8. The near-infrared laser beam generator 1 emits a collimated beam of wide beam that covers and is incident on the micro-mirror array 8. The micro-mirror array 8 controls the path of the emitted light by controlling the angle and direction of each mirror. The micro-mirror array 8 is controlled by logic circuits so that the light emitted by the two sets of row mirrors is directed to the detection area, and the light emitted by the remaining mirrors is directed to the absorption screen 15. In this way, the emitted light is two spaced linear near-infrared laser beams, which are magnified by the lens group to cover the length of the detection unit.

[0074] like Figure 11 and 13 As shown, in this embodiment, for ease of shooting, a 45-degree tilted reflector 5 is set above the beam splitter 4. The near-infrared imaging module 7 used in this embodiment is an area array camera, which is fixed to the left side of the reflector 5. The infrared light reflected back from the detection area is reflected twice by the beam splitter 4 into the imaging optical path of the area array camera, which covers the entire detection area. An external trigger signal enables the area array camera and the micro-mirror array 8 to work synchronously. After receiving the external trigger signal, the area array camera will sequentially expose the image sensor. While a certain pixel row is exposed, two near-infrared laser beams above and below the detection unit of that row are simultaneously irradiated, providing scattered background light to the human tissue below the detection unit as a strong beam incident on the skin. While a certain pixel row is exposed, other pixel rows are in the off state. As each pixel row is exposed sequentially, the infrared image of the entire detection area is captured. The specific implementation method is as follows: Figure 15 and 16As shown, two infrared laser beams reflected by the micro-mirror array 8 irradiate the skin tissue below, that is, they are incident above and below the detection unit. After the near-infrared laser beams are incident, the diffuse reflection light under the skin will be scattered to the detection unit. The exposure of the detection unit and the sensor forms an image relationship. When the two near-infrared laser beams are emitted, a synchronous trigger signal is emitted to make the sensor of the near-infrared imaging module 7 be exposed synchronously. Other rows of pixels are not exposed. When the two infrared laser beams push and scan in the horizontal direction, the pixel rows that image the detection unit also move and are exposed in sequence. After one sweep cycle, the image of all detection units in the detection area is obtained. Through calculation and integration, an image signal with vascular information is obtained.

[0075] This embodiment uses a combination of a micro-mirror array 8 and a surface array camera, which differs from the illumination module and near-infrared imaging module 7 provided in Embodiment 1. The entire control process is more precise and has a better effect.

[0076] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method of near-infrared blood vessel imaging, characterized by, Includes the following steps: The skin surface blood vessel detection area is divided into multiple detection units; Two parallel linear near-infrared beams are used to illuminate the edge of the detection unit one by one and follow it to capture images, generating near-infrared images. A visual image of the entire detection area is generated based on the near-infrared image; two linear near-infrared beams and the optical path of the near-infrared imaging lens are reflected to the detection unit using a reflector, and the multiple detection units are illuminated and photographed by repeatedly swinging the reflector. The reflector swings back and forth within a certain angle range, causing two parallel linear near-infrared beams to sweep across the target area. Simultaneously, the near-infrared imaging module captures images of the area between the two near-infrared beams, i.e., the position of each detection unit, generating row images. One sweeping cycle yields two sets of row images. The row images are arranged in sequence to form a planar image. Specifically, the images obtained when the reflector swings counterclockwise are arranged in positive column order, and the images obtained when the reflector swings clockwise are arranged in negative column order, thus transforming the linear image into a planar image of the entire detection area.

2. The near-infrared angiography method according to claim 1, characterized by, The visible light image is projected onto the original detection area in a 1:1 overlap manner.

3. The near-infrared angiography method according to claim 1 or 2, characterized by, A near-infrared beam with a rectangular cross-section is incident on a micro-mirror array. Two parallel linear mirrors in the micro-mirror array are then controlled in sequence to generate two directional, moving linear near-infrared beams.

4. A near-infrared angiography apparatus for implementing the near-infrared angiography method according to any one of claims 1 to 3, characterized by, include: The illumination module includes a near-infrared beam generator and a light rectifier. The near-infrared beam generator is used to emit near-infrared light, and the light rectifier uses the near-infrared light to generate two directional, linear near-infrared beams. Near-infrared imaging module, used to capture and generate near-infrared images; The calculation and control module calculates and integrates multiple near-infrared images into an image signal with vascular information; The projection module converts the image signal into a visible light image; A beam splitter is used to transmit near-infrared light and reflect visible light images onto the shooting area.

5. The near-infrared angiography apparatus according to claim 4, wherein The light rectifier includes a reflector and a stepper motor. The reflector is located above the beam splitter, and the stepper motor drives the reflector to swing back and forth.

6. The near-infrared angiography apparatus according to claim 5, wherein The near-infrared imaging module is a linear array camera. The infrared beam generators emit near-infrared laser beams with a linear cross-section. There are two near-infrared beam generators, which are respectively set on the upper and lower sides of the linear array camera. The rotation axis of the reflector is located on the center line of the optical path directly in front of the infrared camera.

7. The near-infrared angiography apparatus according to claim 6, wherein The light rectifier is a micro mirror array, which is controlled by a logic circuit. The near-infrared beam generator is installed on one side of the micro mirror array, and an absorption screen is provided on the other side of the micro mirror array.

8. The near-infrared vascular imaging device according to claim 7, characterized in that, A 45° inclined reflector is provided above the beam splitter. The infrared light reflected back from the detection area is reflected a second time by the beam splitter into the imaging optical path of the near-infrared imaging module.

9. The near-infrared vascular imaging device according to any one of claims 4 to 8, characterized in that, It also includes a housing, in which the irradiation module, the near-infrared imaging module, the calculation and control module, the projection module and the beam splitter are all installed, and a light-transmitting hole is provided at the bottom of the housing.

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