Method for measuring hemoglobin concentration and device therefor
Images of blood samples were taken by a multi-spectral camera and hemoglobin concentration was calculated based on the absorption characteristic value, which solved the complex problem of adding drugs and stirring in the prior art, and achieved more convenient and accurate measurement of hemoglobin concentration.
Patent Information
- Application Number
- JP2023152640
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-09-20
- Publication Date
- 2025-04-02
AI Technical Summary
The prior art requires adding drugs and stirring when measuring hemoglobin concentration in the blood, which limits the application scope of the method and is complex in operation.
Images of blood samples were taken using a multispectral camera, and the hemoglobin concentration was calculated based on the absorption characteristic values, without the need for drug addition, simplifying the measurement process.
It realizes more convenient measurement of hemoglobin concentration in the blood, improves the accuracy and simplicity of measurement, and expands the application scope of the method.
Smart Images
Figure 2025044843000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a method and an apparatus for measuring hemoglobin concentration. [Background technology]
[0002] Conventionally, a method has been proposed in which a drug is added to blood to measure the hemoglobin concentration in the blood (for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]
[0003] [Non-Patent Document 1] Xiaoxi Yang, et.al., “Simple Paper-Based Test for Measuring Blood Hemoglobin Concentration in Resource-Limited Settings”, Clinical Chemistry 59 (10), pp. 1506-1513, 2013-10-01 Summary of the Invention [Problem to be solved by the invention]
[0004] However, in the above-mentioned conventional technique, it is necessary to add and mix a drug with a predetermined volume of blood, which limits the scope of application of the method for measuring hemoglobin concentration.
[0005] Therefore, the present disclosure provides a method for measuring hemoglobin concentration, which can more easily measure the hemoglobin concentration in blood. [Means for solving the problem]
[0006] A method for measuring hemoglobin concentration according to one aspect of the present disclosure is a method for measuring the hemoglobin concentration in blood spread in an absorbent body, and calculates the hemoglobin concentration based on an absorption characteristic value derived from hemoglobin in an image of the blood captured by a multispectral camera.
[0007] This comprehensive or specific aspect may be realized by an apparatus, a system, an integrated circuit, a computer program, or a computer-readable recording medium, or may be realized by any combination of an apparatus, a system, a method, an integrated circuit, a computer program, and a recording medium. The computer-readable recording medium includes a non-volatile recording medium such as a CD-ROM (Compact Disc-Read Only Memory). Effect of the Invention
[0008] According to the present disclosure, the hemoglobin concentration in blood can be measured more easily. [Brief description of the drawings]
[0009] [Figure 1] FIG. 1 is a perspective view of a measurement device according to an embodiment. [Diagram 2] FIG. 2 is a functional configuration diagram of the measurement device according to the embodiment. [Diagram 3] FIG. 3 is a diagram showing an example of an image captured by the camera according to the embodiment. [Figure 4] FIG. 4 is a graph showing the wavelength characteristics of the absorption coefficients of hemoglobin and oxyhemoglobin. [Diagram 5] FIG. 5 is a diagram illustrating an example of the calibration data according to the embodiment. [Figure 6] FIG. 6 is a flowchart showing a method for measuring a hemoglobin concentration according to an embodiment. [Figure 7] FIG. 7 is a flowchart showing a method for measuring a hemoglobin concentration according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] (Summary of the Disclosure) Before describing the embodiments, an overview of the present disclosure will be described.
[0011] A method for measuring hemoglobin concentration according to a first aspect of the present disclosure is a method for measuring the hemoglobin concentration in blood spread in an absorbent body, and calculates the hemoglobin concentration based on an absorption characteristic value derived from hemoglobin in an image of the blood captured by a multispectral camera.
[0012] This makes it possible to more easily measure the hemoglobin concentration without the need to add a drug to and mix with blood as in Patent Document 1. In addition, it is possible to utilize the correlation between the hemoglobin concentration and the light absorption characteristic value derived from hemoglobin in the image, thereby improving the measurement accuracy in the simpler measurement of the hemoglobin concentration.
[0013] A method for measuring hemoglobin concentration according to a second aspect of the present disclosure is the method for measuring hemoglobin concentration according to the first aspect, further comprising determining a reflected light intensity in a predetermined wavelength range in each of a blood region and a non-blood region in the image, and calculating an absorption characteristic value derived from the hemoglobin based on the negative logarithm of a ratio of the reflected light intensity of the blood region to the reflected light intensity of the non-blood region.
[0014] According to this, the hemoglobin-derived light absorption characteristic value is calculated based on the negative logarithm of the ratio of the reflected light intensity of the blood region to the non-blood region. The negative logarithm of the ratio of the reflected light intensity of the blood region to the non-blood region corresponds to the absorbance of the scatterer in the absence of transmitted light. Therefore, the relationship between the hemoglobin concentration and the light absorption characteristic value can be expressed as a linear relationship, and the measurement accuracy of the hemoglobin concentration can be improved.
[0015] A method for measuring hemoglobin concentration according to a third aspect of the present disclosure is the method for measuring hemoglobin concentration according to the second aspect, wherein the predetermined wavelength range is any one of 500 nm, 520 nm, and 800 nm.
[0016] According to this, the absorption characteristic value is calculated based on the reflected light intensity in a wavelength range in which the absorption coefficient of hemoglobin and the absorption coefficient of oxyhemoglobin are similar to each other, so that fluctuations in the measured hemoglobin concentration due to the ratio of hemoglobin and oxyhemoglobin contained in blood can be suppressed, and the measurement accuracy of the hemoglobin concentration can be improved.
[0017] A method for measuring hemoglobin concentration according to a fourth aspect of the present disclosure is the method for measuring hemoglobin concentration according to any one of the first to third aspects, wherein the calculation of the hemoglobin concentration involves calculating the hemoglobin concentration corresponding to a plurality of light absorption characteristic values using calibration data indicating a relationship between the plurality of light absorption characteristic values and a plurality of hemoglobin concentrations.
[0018] According to this, by preparing calibration data according to conditions such as the absorber, blood, lighting, and camera, the measurement accuracy of the hemoglobin concentration can be further improved.
[0019] A method for measuring hemoglobin concentration according to a fifth aspect of the present disclosure is a method for measuring hemoglobin concentration according to any one of the first to fourth aspects, wherein the multispectral camera is a hyperspectral camera capable of capturing four or more spectroscopic images.
[0020] This makes it possible to capture a spectral image in a narrower wavelength range, and to more accurately calculate the light absorption characteristic value derived from hemoglobin.
[0021] A method for measuring hemoglobin concentration according to a sixth aspect of the present disclosure is a method for measuring hemoglobin concentration according to any one of the first to fifth aspects, wherein the blood spread on the absorbent body is blood that has not been treated with a drug.
[0022] According to this, there is no need to add a drug to the blood and mix it as in Patent Document 1, and the hemoglobin concentration can be measured more easily.
[0023] A hemoglobin concentration measuring device according to a seventh aspect of the present disclosure is a measuring device that measures the hemoglobin concentration in blood spread on an absorbent body, and includes a multispectral camera and a computer that calculates the hemoglobin concentration based on an absorption characteristic value derived from hemoglobin in an image of the blood captured by the multispectral camera.
[0024] This can provide the same effects as the above-mentioned method for measuring hemoglobin concentration.
[0025] (Embodiment) Hereinafter, the embodiment will be specifically described with reference to the drawings.
[0026] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the technology of the present disclosure.
[0027] Each figure is a schematic diagram and is not necessarily precisely illustrated. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, the same reference numerals are used for substantially the same configurations, and duplicated explanations may be omitted or simplified.
[0028] In the following, terms indicating the relationship between elements, such as parallel or perpendicular, terms indicating the shape of elements, such as cylinder or prism, and numerical ranges are not expressions that only express a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.
[0029] [Configuration of the measuring device 100] First, the configuration of a hemoglobin concentration measuring device 100 according to the present embodiment will be described with reference to Figs. 1 and 2. Fig. 1 is a perspective view of the hemoglobin concentration measuring device 100 according to the present embodiment. Fig. 2 is a functional configuration diagram of the hemoglobin concentration measuring device 100 according to the present embodiment. Note that Figs. 1 and 2 show an exemplary structure and configuration of the measuring device 100, and the structure and configuration of the measuring device 100 are not limited to Figs. 1 and 2. Therefore, the description of the measuring device 100 provided below should not be interpreted in a restrictive manner.
[0030] The measuring device 100 according to this embodiment includes a computer 10, a camera 20, and a light source 30, and is capable of measuring the hemoglobin concentration in blood 201 spread in an absorber 200.
[0031] The absorbent body 200 is a sheet-like object capable of absorbing blood 201. For example, filter paper, a highly absorbent polymer, or the like can be used as the absorbent body 200. In this embodiment, a sanitary napkin made of a highly absorbent polymer is used as the absorbent body 200.
[0032] The computer 10 is connected to the camera 20 and can acquire a hyperspectral image from the camera 20. The computer 10 may further be connected to a light source 30 and may be capable of controlling the light source 30. The computer 10 may also be included in the camera 20. The functional configuration of the computer 10 will be described later.
[0033] Camera 20 is a multispectral camera capable of capturing a plurality of spectroscopic images, and can capture an image of blood 201 spread on absorber 200. Fig. 3 is a diagram showing an example of image 210 captured by camera 20 according to this embodiment. In Fig. 3, blood region 211 is a part or all of the region of absorber 200 where blood 201 is spread. Non-blood region 212 is a part or all of the region of absorber 200 where blood 201 is not spread.
[0034] In FIG. 1, camera 20 has a cylindrical shape and penetrates the hollow portion of annular light source 30. In this embodiment, camera 20 is a hyperspectral camera capable of capturing four or more spectral images. For example, camera 20 can capture the wavelength ranges of visible light and near-infrared light by dispersing them in units of a predetermined wavelength width (e.g., 20 nanometers). Note that camera 20 may be a red (R), green (G), and blue (B) camera. In other words, camera 20 is not limited to a hyperspectral camera as long as it is a multispectral camera capable of capturing a plurality of spectral images.
[0035] The light source 30 is a broadband LED (Light Emitting Diode) and can irradiate light onto the absorber 200 in which the blood 201 is spread. The light source 30 is not limited to a broadband LED. For example, the light source 30 may be an incandescent light bulb, a fluorescent lamp, a metal halide lamp, or a flashlight. In order to eliminate the influence of external light, it is preferable to perform the imaging in a darkroom.
[0036] [Computer 10 Configuration] Next, the configuration of the computer 10 according to the present embodiment will be described with reference to Fig. 2. As shown in Fig. 2, the computer 10 includes an absorption characteristics calculation unit 11, a concentration calculation unit 12, and a storage unit 13.
[0037] The light absorption characteristic calculation unit 11 calculates a light absorption characteristic value derived from hemoglobin in the image 210 of the blood 201 captured by the camera 20. The light absorption characteristic value derived from hemoglobin is a value indicating the degree of attenuation of light by hemoglobin. In this embodiment, the light absorption characteristic value derived from hemoglobin (A) is the negative logarithm of the ratio of the reflected light intensity (R1) in a predetermined wavelength range in the blood region 211 in the image 210 to the reflected light intensity (R2) in a predetermined wavelength range in the non-blood region 212 in the image 210 (see the following formula (1)). In other words, the light absorption characteristic value derived from hemoglobin (A) is the sum of the negative logarithm of the reflected light intensity (R1) in a predetermined wavelength range in the blood region 211 in the image 210 and the positive logarithm of the reflected light intensity (R2) in a predetermined wavelength range in the non-blood region 212 in the image 210.
[0038]
number
[0039] The light absorption characteristic value is not limited to the formula (1). For example, depending on the characteristics of the camera 20, the light source 30, and the absorber 200, the light absorption characteristic value of the formula (1) may be multiplied by an arbitrary coefficient or may be added with an arbitrary constant.
[0040] The predetermined wavelength range can be determined based on the wavelength characteristics of the absorption coefficients of hemoglobin (Hb) and oxyhemoglobin (HbO2). For example, by using a wavelength range in which the absorption coefficients of hemoglobin and oxyhemoglobin are similar to each other as the predetermined wavelength range, the measurement accuracy of the hemoglobin concentration in blood 201 can be improved.
[0041] Here, the predetermined wavelength range will be described in more detail with reference to Fig. 4. Fig. 4 is a graph showing the wavelength characteristics of the absorption coefficients of hemoglobin and oxyhemoglobin. In Fig. 4, the horizontal axis shows wavelength, and the vertical axis shows the absorption coefficients of hemoglobin and oxyhemoglobin.
[0042] As shown in Fig. 4, in the wavelength range of 500 nm to 600 nm, the absorption coefficient of hemoglobin is similar to that of oxyhemoglobin. Therefore, the predetermined wavelength range may be a wavelength range of 500 nm to 600 nm. More specifically, the predetermined wavelength range may be a wavelength range of 500 nm and / or a wavelength range of 520 nm. In this case, the width of the wavelength range may be, for example, 20 nm. In other words, the predetermined wavelength range may be a wavelength range of 490 nm to 510 nm and / or a wavelength range of 510 nm to 530 nm.
[0043] The predetermined wavelength range is not limited to the above wavelength range. For example, the predetermined wavelength range may be a wavelength range of near-infrared light. Specifically, the predetermined wavelength range may be, for example, a wavelength range of 800 nm. Even in such a wavelength range, the absorption coefficient of hemoglobin is similar to that of oxyhemoglobin, so that the same effect as that in the wavelength range of 500 nm or more and 600 nm or less can be obtained.
[0044] The concentration calculation unit 12 calculates the hemoglobin concentration based on the hemoglobin-derived light absorption characteristic value. The hemoglobin concentration represents the amount of hemoglobin and oxyhemoglobin contained in a unit volume (for example, 1 deciliter) of blood.
[0045] Specifically, the concentration calculation unit 12 obtains the hemoglobin concentration corresponding to the light absorption characteristic value calculated by the light absorption characteristic calculation unit 11 using calibration data 14 indicating the relationship between multiple light absorption characteristic values and multiple hemoglobin concentrations.
[0046] Fig. 5 is a diagram showing an example of calibration data 14 according to the present embodiment. In Fig. 5, the calibration data 14 is expressed in a table format in which a plurality of light absorption characteristic values and a plurality of hemoglobin concentrations are in one-to-one correspondence. By referring to the calibration data 14 in Fig. 5, for example, when the light absorption characteristic value is 0.3, a hemoglobin concentration of 1.5 (g / dL) is obtained.
[0047] The calibration data 14 is not limited to table-format data as shown in Fig. 5. For example, the calibration data 14 may be mathematical data expressing the relationship between a plurality of light absorption characteristic values and a plurality of hemoglobin concentrations. For example, an approximation formula can be estimated by performing linear regression analysis on the plurality of light absorption characteristic values and a plurality of hemoglobin concentrations.
[0048] Here, y represents the hemoglobin concentration (g / dL) and x represents the light absorption characteristic value. Note that the approximation formula used as the calibration data 14 is not limited to a linear function.
[0049] The storage unit 13 is, for example, a hard disk drive, a solid state drive, or the like, and stores the calibration data 14. The calibration data 14 can be generated by photographing an absorbent body in which blood with a known hemoglobin concentration is spread. The calibration data 14 may be stored in advance for each type of absorbent body, for example.
[0050] It should be noted that all or part of the functions or operations of the computer 10 can be executed by software processing. In this case, the software program is recorded in a non-transitory recording medium (e.g., one or more semiconductor memories, one or more optical disks, one or more hard disk drives, one or more solid-state drives, etc.), and when the software program is executed by a processor, the functions specified in the software program are executed by the processor and peripheral devices. In this case, the computer 10 may include one or more non-transitory recording media on which the software program is recorded, a processor, and necessary hardware devices (e.g., interfaces).
[0051] Also, all or part of the computer 10 may be implemented by one or more electronic circuits including, for example, a semiconductor device, a semiconductor integrated circuit (IC), or an LSI (large scale integration). The LSI or IC may be integrated into one chip or may be configured by combining multiple chips. Although the term LSI or IC is used here, the term may be changed depending on the degree of integration, and may be called a system LSI, a VLSI (very large scale integration), or an ULSI (ultra large scale integration). A field programmable gate array (FPGA), which is programmed after the LSI is manufactured, or a reconfigurable logic device (RLD), which can reconfigure the connection relationship inside the LSI or set up the circuit partition inside the LSI, may also be used for the same purpose.
[0052] [Method of measuring hemoglobin concentration] Next, a method for measuring a hemoglobin concentration using the measuring device 100 configured as above will be described with reference to Figures 6 and 7. Figures 6 and 7 are flow charts showing a method for measuring a hemoglobin concentration according to this embodiment.
[0053] <Step S10> The user places the absorber 200 on which the blood 201 is spread in the photographing area of the camera 20. As a result, the absorber 200 is placed in an area that can be photographed by the camera 20, as shown in Fig. 1. Note that step S10 is an optional step and does not need to be included in the method for measuring the hemoglobin concentration.
[0054] <Step S20> The light source 30 irradiates the absorber 200 with light. For example, a user turns on the light source 30, so that the absorber is irradiated with light. Turning on the light source 30 may be controlled by the computer 10. Step S20 is an optional step and may not be included in the method for measuring a hemoglobin concentration.
[0055] <Step S30> The camera 20 captures an image of the absorber 200. This provides an image 210 of blood 201 spread on the absorber 200. Step S30 is an optional step, and does not have to be included in the method for measuring a hemoglobin concentration.
[0056] <Step S40> The computer 10 calculates the hemoglobin concentration based on the light absorption characteristic value derived from hemoglobin in the image 210 captured by the camera 20 (S40). Details of this process will be described with reference to FIG.
[0057] <Step S41> The light absorption characteristic calculation unit 11 identifies the blood region 211 and the non-blood region 212 in the image 210. For example, the light absorption characteristic calculation unit 11 identifies the blood region 211 and the non-blood region 212 based on a user input specifying the blood region 211 and the non-blood region 212. In addition, for example, the light absorption characteristic calculation unit 11 may automatically recognize the blood region 211 and the non-blood region 212 in the image 210. In this case, the technology of the automatic recognition is not particularly limited. For example, the blood region 211 and the non-blood region 212 may be automatically recognized by threshold processing or machine learning.
[0058] <Step S42> Light absorption characteristic calculation unit 11 obtains the reflected light intensity in a predetermined wavelength range in each of blood region 211 and non-blood region 212. Specifically, light absorption characteristic calculation unit 11 calculates a representative value of the luminance value of each of blood region 211 and non-blood region 212 in a spectroscopic image of a predetermined wavelength range as the reflected light intensity. Note that the representative value may be any of an average value, a maximum value, a median value, and a mode, and is not particularly limited.
[0059] <Step S43> The light absorption characteristic calculation unit 11 calculates the light absorption characteristic value derived from hemoglobin using the determined reflected light intensity of the blood region 211 and the determined reflected light intensity of the non-blood region 212. For example, the light absorption characteristic calculation unit 11 calculates the light absorption characteristic value derived from hemoglobin based on the negative logarithm of the ratio of the reflected light intensity of the blood region 211 to the reflected light intensity of the non-blood region 212. Specifically, the light absorption characteristic calculation unit 11 calculates the light absorption characteristic value derived from hemoglobin (A) by substituting the determined reflected light intensity (R1) of the blood region 211 and the reflected light intensity (R2) of the non-blood region 212 into, for example, equation (1).
[0060] <Step S44> The concentration calculation unit 12 calculates the hemoglobin concentration based on the calculated light absorption characteristic value. Specifically, the concentration calculation unit 12 calculates the hemoglobin concentration corresponding to the calculated light absorption characteristic value using calibration data 14 indicating the relationship between the multiple light absorption characteristic values and the multiple hemoglobin concentrations.
[0061] (Modification) Although the hemoglobin concentration measuring device and measuring method have been described above based on the embodiments, the measuring device and measuring method according to the present disclosure are not limited to the above-mentioned embodiments. The present disclosure also includes other embodiments realized by combining any of the components in the above-mentioned embodiments, and modified versions obtained by applying various modifications to the above-mentioned embodiments that would come to mind by a person skilled in the art without departing from the spirit of the present disclosure.
[0062] For example, in the above embodiment, the computer 10 is connected to the camera 20 by wire, but may be connected wirelessly. Also, the computer 10 may be a cloud computer, and may be connected to the camera 20 via the Internet or the like. [Industrial Applicability]
[0063] The present disclosure can be used in a measurement device for measuring the hemoglobin concentration in blood. [Explanation of symbols]
[0064] 10. Computers 11. Absorption characteristic calculation section 12 Concentration calculation section 13 Storage section 14 Calibration Data 20 Camera 30 light source 100 Measuring Equipment 200 Absorbent 201 Blood 210 images 211 Blood area 212 Non-blood area
Claims
1. A method for measuring a hemoglobin concentration in blood spread on an absorbent body, comprising the steps of: calculating a hemoglobin concentration based on a light absorption characteristic value derived from hemoglobin in the image of the blood captured by the multispectral camera; How to measure hemoglobin concentration.
2. moreover, determining reflected light intensities in a predetermined wavelength range in each of a blood region and a non-blood region in the image; calculating a light absorption characteristic value derived from hemoglobin based on the negative logarithm of a ratio of the reflected light intensity of the blood region to the reflected light intensity of the non-blood region; The method for measuring hemoglobin concentration according to claim 1.
3. The predetermined wavelength range is any one of 500 nm, 520 nm, and 800 nm. The method for measuring hemoglobin concentration according to claim 2.
4. In the calculation of the hemoglobin concentration, a hemoglobin concentration corresponding to the light absorption characteristic value is calculated using calibration data indicating a relationship between a plurality of light absorption characteristic values and a plurality of hemoglobin concentrations. The method for measuring hemoglobin concentration according to any one of claims 1 to 3.
5. The multispectral camera is a hyperspectral camera capable of capturing four or more spectral images. The method for measuring hemoglobin concentration according to any one of claims 1 to 3.
6. The blood spread on the absorbent body is blood that has not been treated with a drug. The method for measuring hemoglobin concentration according to any one of claims 1 to 3.
7. A measuring device for measuring a hemoglobin concentration in blood spread on an absorbent body, comprising: A multispectral camera; and a computer that calculates a hemoglobin concentration based on a light absorption characteristic value derived from hemoglobin in the image of the blood captured by the multispectral camera. A device for measuring hemoglobin concentration.