Blood supply monitor

Abstract

The invention discloses a blood supply monitor. The near-infrared projection assembly is modulated through spatial light to emit infrared light, and reflected light is collected through the image acquisition device; the emitted infrared light is modulated by means of a spatial light modulation system and a camera cooperative control assembly, and a complementary blood vessel infrared image is obtained; and the transmissivity, the reflectivity and the absorptivity of the monitored target are analyzed according to the images, so that the blood supply condition is judged. The blood vessel imaging quality and the parameter calculation precision are improved, and rapid recognition and early warning of the blood supply condition are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of medical health technology and relates to a blood circulation monitor. Background Art

[0002] Hemoglobin in blood has a much higher absorption in the near-infrared band than surrounding tissue. Blood vessels absorb backscattered infrared light, creating dark shadows on the skin surface. These shadows can be used to locate blood vessels.

[0003] Traditional vascular imaging methods have difficulty providing high-resolution and clear images, especially for deep or tiny vascular structures, resulting in the inability to accurately extract key parameters such as vascular transmittance, reflectivity, and absorptivity from infrared images. Summary of the Invention

[0004] In order to solve the problems existing in the background technology, the present invention proposes a blood circulation monitor.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A blood circulation monitor, comprising:

[0007] The infrared light is emitted to the monitoring target by the spatial light modulation near-infrared projection component, and the infrared light reflected by the monitoring target is collected by the image acquisition device;

[0008] The emitted infrared light is modulated by the spatial light modulation system and the camera cooperative control component to obtain a set of vascular infrared images that complement each other and contain local vascular information;

[0009] The transmittance, reflectivity and absorptivity of the monitored target are analyzed based on the infrared image of blood vessels to determine the blood circulation status.

[0010] Furthermore, the specific method of emitting infrared light through the spatial light modulation near-infrared projection component is:

[0011] Modulating the next infrared light emission plan based on the previous infrared light emission plan;

[0012] Each time infrared light is emitted, the next infrared light emission plan is modulated and multiple rounds of iterations are performed.

[0013] Furthermore, a specific method for obtaining a set of complementary vascular infrared images containing local vascular information is as follows:

[0014] A capillary search model is established based on the neurovascular coupling mechanism and Beer-Lambert law to identify capillaries and fuse multiple vascular infrared images.

[0015] Furthermore, the specific method for analyzing the transmittance, reflectance and absorptance of the monitoring target based on the blood vessel infrared image is as follows:

[0016] A temperature monitoring model is established based on Planck's law, and the changes in hot spots in vascular infrared images are extracted to determine the blood flow of subcutaneous blood vessels.

[0017] By extracting the vascular image from the vascular infrared image, the transmittance, reflectance and absorptivity of the vascular to infrared light are calculated, and the emissivity of the vascular to infrared light is determined;

[0018] The radiation characteristics of the blood vessels with respect to infrared light are determined based on the transmittance, reflectance, absorptivity and emissivity of the blood vessels to infrared light.

[0019] Furthermore, blood circulation is judged by skin color, fingertip tension, skin temperature, and capillary refill time;

[0020] Skin color is determined based on the skin's absorption and reflectivity of infrared light;

[0021] Skin temperature is determined based on the emissivity of infrared light, the spectral radiant energy at wavelength λ and temperature T, and the spectral radiant energy at the same wavelength λ and temperature T;

[0022] Capillary filling time and fingertip tension are determined based on multiple vascular infrared images collected at different time points of the same target.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention adopts spatial light modulation technology and neurovascular coupling mechanism to improve the quality and accuracy of vascular imaging.

[0025] The present invention establishes a detailed mathematical model based on Planck's law and other physical laws, which can accurately calculate these parameters and evaluate the health status of blood vessels accordingly.

[0026] The present invention realizes rapid identification, evaluation and early warning of blood circulation status by continuously collecting and analyzing vascular infrared images and combining multiple physiological indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the operating method of the blood circulation detector of the present invention;

[0028] Figure 2 It is a schematic diagram of the blood circulation detector device of the present invention;

[0029] The markings in the accompanying drawings are: 1. Spatial light modulation near-infrared projection component; 2. Image acquisition device; 3. Spatial light modulation system and camera collaborative control component; 4. Monitoring target. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] like Figure 1-Figure 2 As shown, the technical solution adopted by the present invention is as follows: a blood circulation detector, comprising:

[0032] The near-infrared projection assembly 1 emits infrared light onto the monitoring target 4 through spatial light modulation, and the infrared light reflected by the monitoring target 4 is collected by the image acquisition device 2 .

[0033] By continuously adjusting the infrared light emission scheme of the spatial light modulation near-infrared projection component 1 through the spatial light modulation system and the camera cooperative control component 3, a set of vascular infrared images that complement each other and contain local vascular information are obtained.

[0034] The transmittance, reflectance and absorptivity of the monitoring target 4 are analyzed based on the infrared image of the blood vessels to determine the blood circulation status.

[0035] Hemoglobin in blood has a much higher absorption in the near-infrared band than surrounding tissue. Blood vessels absorb backscattered infrared light, creating dark shadows on the skin surface. These shadows can be used to locate blood vessels.

[0036] The principle of spatial light modulation detection technology stems from the fact that near-infrared light in the 700nm-1100nm wavelength range has high scattering properties and a large penetration depth within human skin, fat, and muscle tissue. Near-infrared light modulated by the spatial light modulation near-infrared projection component 1 is projected onto a target location on the human body surface. The image acquisition device 2 captures the pattern of the monitoring target 4, producing an image of alternating light and dark areas. The dark areas of the image contain vascular information with a high signal-to-noise ratio. The spatial light modulation system and camera control component 3 coordinate to change the infrared light modulation scheme through multiple iterations.

[0037] The next infrared light emission scheme is modulated based on the previous infrared light emission scheme. The next infrared light emission scheme is modulated each time infrared light is emitted, and multiple rounds of iterations are performed.

[0038] Based on the neurovascular coupling mechanism and Beer-Lambert law, a capillary search model is established to identify capillaries and fuse multiple vascular infrared images to obtain a set of complementary vascular infrared images containing local vascular information.

[0039] Infrared thermal imaging technology can determine the blood flow of subcutaneous blood vessels by observing the changes in hot spots in the thermal imaging image of the skin flap.

[0040] In the fields of thermal radiation and optics, parameters describing the surface characteristics of an object include transmittance t λ , reflectivity r λ and absorption rate a λ , these parameters are usually related to the wavelength λ.

[0041] Based on Planck's law, a temperature monitoring model is established to extract the changes in hot spots in the vascular infrared image to determine the blood circulation of the subcutaneous blood vessels. The temperature monitoring model obtains the transmittance t fed back from the vascular infrared image. λ , reflectivity r λ and absorption rate a λ Parameters are calculated.

[0042] Transmittance t λ It indicates the ability of an object to allow radiation of a specific wavelength to pass through. It is defined as the ratio of the radiation energy passing through the object to the incident radiation energy. For opaque objects, t λ =0.

[0043] Reflectivity r λ It indicates the ability of an object's surface to reflect radiation of a specific wavelength, defined as the ratio of the reflected radiation energy to the incident radiation energy.

[0044] Absorption rate λ It indicates the ability of an object to absorb radiation of a specific wavelength and is defined as the ratio of absorbed radiation energy to incident radiation energy.

[0045] According to the law of conservation of energy, the incident radiation energy is equal to the sum of the transmitted, reflected and absorbed radiation energy, so:

[0046] t λ +r λ +a λ =1;

[0047] Through the transmittance t λ , reflectivity r λ and absorption rate a λ Ability to calculate emissivity E λ , emissivity E λ Indicates the ability of an object to emit radiation of a specific wavelength. According to Kirchhoff's law of thermal radiation, in thermal equilibrium, the emissivity is equal to the absorptivity, so:

[0048] E λ =1-t λ -r λ ;

[0049] Transmittance t λ , reflectivity r λ, Absorption rate a λ and emissivity E λ Together they determine the radiation characteristics of an object at different wavelengths. The emissivity coefficient can be used as a variable in Planck's equation to describe the surface characteristics of an object relative to the wavelength. Most objects being measured are opaque, and the emissivity coefficient can be simplified to E λ =1-r λ .

[0050] Through the transmittance t λ , reflectivity r λ , Absorption rate a λ and emissivity E λ Calculating the surface temperature of the monitoring target 4 requires fast response characteristics in the medical and health field. Fast response sensors require the use of fast response controllers, thyristor power supply components and other regulators.

[0051] For applications with absolute accuracy, and where the product is undergoing physical or chemical changes, dual-wavelength or multi-wavelength thermometry should be considered. The concept of ratio radiometers has been around since the early 1950s, but recent design and hardware improvements have improved performance, provided cryogenic capabilities, and reduced costs.

[0052] Dual-wavelength ratiometric thermometry involves measuring the spectral energy emitted in two different wavelength regions. If the emissivity values are identical in both wavelength regions, the target temperature can be read directly from the instrument. This type of instrument can also indicate the correct target temperature when part of the field of view is obscured by a relatively cool object, such as dust, metal mesh, or a gray transparent window in the aiming path.

[0053] The theory behind this design is straightforward and can be illustrated by the following equations. In these equations, we use Planck's equation to calculate the energy in one wavelength region and then find the ratio of that energy to the energy in another wavelength region.

[0054] The spectral radiance ratio (SRR) is the ratio of an object's radiant energy at a specific wavelength or wavelength band to the radiant energy of an ideal blackbody at the same wavelength and temperature. It reflects the relative strength of an object's radiant ability at a given wavelength compared to a blackbody. While the SRR of a blackbody is 1, the SRR of real objects is typically less than 1. The SRR at wavelength λ and temperature T is calculated by dividing the object's spectral radiant energy at wavelength λ and temperature T by the blackbody's spectral radiant energy at the same wavelength and temperature.

[0055] The ratio temperature of a surface is the temperature derived by measuring the radiant energy emitted by an object and assuming the object is a black body. The ratio temperature is an equivalent temperature that reflects the radiation characteristics of an object's surface, but it is not necessarily equal to the object's true temperature. If the object's emissivity is less than 1, the ratio temperature will be lower than the true temperature.

[0056] Spectral emissivity is the ratio of an object's emissivity at a specific wavelength to the emissivity of an ideal blackbody at the same wavelength and temperature. Spectral emissivity describes the radiation characteristics of an object at a specific wavelength. It is a dimensionless quantity with a range of 0 ≤ blackbody spectral emissivity ≤ 1. For a blackbody, the blackbody spectral emissivity = 1; for a real object, the blackbody spectral emissivity is < 1.

[0057] The ratio temperature is based on the temperature inversely calculated when the object is a black body. If the spectral emissivity of the object is known, the ratio temperature can be converted to the true temperature using the following formula:

[0058] I λ (λ, T) = e λ ·B λ (λ, T);

[0059] Among them I λ (λ, T) is the spectral radiation energy of the object at wavelength λ and temperature T; e λ is the emissivity of the object; B λ (λ, T) is the spectral radiation energy of the black body at wavelength λ and temperature T. By measuring and knowing it, the true temperature can be solved.

[0060] Classic observation indicators for postoperative blood circulation observation were selected for quantification, including skin color, fingertip tension, skin temperature, and capillary refill time.

[0061] Skin color is determined based on the skin's absorption and reflectivity of infrared light;

[0062] Skin temperature is determined based on the emissivity of infrared light, the spectral radiant energy at wavelength λ and temperature T, and the spectral radiant energy at the same wavelength λ and temperature T;

[0063] Capillary filling time and fingertip tension are determined based on multiple vascular infrared images collected at different time points of the same target.

[0064] Quantifying and assigning values to the collected data helps improve medical staff's observation of patients' limb blood circulation and the detection rate of vascular lesions, playing a positive role in preoperative and postoperative limb blood circulation assessment and the prevention and treatment of vascular lesions. Operators complete the entire process by following the step-by-step process, which is recorded electronically. Any abnormalities are promptly reported to the doctor for comprehensive assessment and early treatment.

[0065] The quantitative classification can be assigned according to the table below.

[0066]

[0067] The method described in the present invention is used to quantify the collected data and assign values according to the above table, which helps improve medical staff's judgment of postoperative blood circulation and the detection rate of vascular lesions, and plays a positive role in the assessment of patients' limb blood circulation before and after surgery and the prevention and treatment of vascular lesions.

[0068] In addition, skin temperature, skin color, tissue tension, blood vessel diameter, blood flow rate in blood vessels, and capillary distribution are planned according to the process. The operator can complete the entire process by following the process step by step, and the records are recorded electronically. If there are any abnormal situations, an alarm will be issued to the doctor in time for comprehensive judgment and early treatment.

[0069] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A blood circulation monitor, characterized in that: Includes: The near-infrared projection component (1) emits infrared light onto the monitoring target (4), and the image acquisition device (2) acquires the infrared light reflected by the monitoring target (4); The emitted infrared light is modulated by a spatial light modulation system and a camera cooperative control component (3) to obtain a set of vascular infrared images that complement each other and contain local vascular information; The transmittance, reflectance and absorptivity of the monitoring target (4) are analyzed based on the infrared image of the blood vessels to judge the blood circulation status.

2. A blood circulation monitor according to claim 1, characterized in that: The specific method of emitting infrared light by the spatial light modulation near-infrared projection component (1) is as follows: Modulating the next infrared light emission plan based on the previous infrared light emission plan; Each time infrared light is emitted, the next infrared light emission plan is modulated and multiple rounds of iterations are performed.

3. The blood circulation monitor according to claim 1, characterized in that: The specific method for obtaining a set of complementary vascular infrared images containing local vascular information is as follows: A capillary search model is established based on the neurovascular coupling mechanism and Beer-Lambert law to identify capillaries and fuse multiple vascular infrared images.

4. The blood circulation monitor according to claim 1, characterized in that: The specific method of analyzing the transmittance, reflectance and absorptance of the monitoring target (4) based on the infrared image of the blood vessels is as follows: A temperature monitoring model is established based on Planck's law, and the changes in hot spots in vascular infrared images are extracted to determine the blood flow of subcutaneous blood vessels. By extracting the vascular image from the vascular infrared image, the transmittance, reflectance and absorptivity of the vascular to infrared light are calculated, and the emissivity of the vascular to infrared light is determined; The radiation characteristics of the blood vessels with respect to infrared light are determined based on the transmittance, reflectance, absorptivity and emissivity of the blood vessels to infrared light.

5. The blood circulation monitor according to claim 1, characterized in that: Blood circulation is judged by skin color, fingertip tension, skin temperature, and capillary refill time; Skin color is determined based on the skin's absorption and reflectivity of infrared light; Skin temperature is determined based on the emissivity of infrared light, the spectral radiant energy at wavelength λ and temperature T, and the spectral radiant energy at the same wavelength λ and temperature T; Capillary filling time and fingertip tension are determined based on multiple vascular infrared images collected at different time points of the same target.

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