WO2013061681A1

WO2013061681A1 - Component measurement device and component measurement method

Info

Publication number: WO2013061681A1
Application number: PCT/JP2012/071589
Authority: WO
Inventors: 秀幸桃木
Original assignee: テルモ株式会社
Priority date: 2011-10-18
Filing date: 2012-08-27
Publication date: 2013-05-02
Also published as: TW201319550A; JP2015004510A

Abstract

Provided is a component measurement device capable of accurately calculating the concentration of a specific component in a specimen even when the development speed of the specimen on a test paper has changed. This component measurement device (100) is a component measurement device for, on the basis of the color development degree of a reagent that reacts with a component contained in a specimen, measuring the concentration of the component, and comprises an application means (120), a detection means (140), and a component concentration calculation means (180). The application means (120) applies light onto a test paper (111) to which the specimen adheres. The detection means (140) detects reflected light reflected by each of a plurality of different regions on the test paper (111). The component concentration calculation means (180) calculates the concentration of the component contained in the specimen on the basis of the intensity of the reflected light at a termination time after a lapse of a predetermined time from the start time at which the specimen infiltrated and color development started in each of the plurality of different regions.

Description

Component measuring apparatus and component measuring method

The present invention relates to a component measuring apparatus and a component measuring method.

An apparatus for measuring the concentration of a specific component in body fluid, for example, glucose in blood by a colorimetric method is known. In such a colorimetric component measuring apparatus, the collected body fluid (hereinafter referred to as a specimen) is spotted on a test paper coated with a reagent. The spotted specimen is developed on a test paper and reacts with the reagent to cause a color reaction according to the concentration of the specific component. The colorimetric component measuring apparatus calculates the concentration of the specific component contained in the specimen by optically measuring the color generated by the color reaction.

Generally, the speed at which a specimen is developed on a test paper (hereinafter referred to as specimen development speed) can vary depending on various factors such as specimen quantity, specimen properties, environmental temperature, and variations in test paper production. If the development speed of the specimen on the test paper changes due to such factors, for example, the specimen does not sufficiently develop on the test paper within the measurement time, or the start of the color reaction is delayed. As a result, it is difficult to correctly calculate the concentration of the specific component in the sample.

As a technique for coping with a case where the specimen does not sufficiently develop on the test paper, an apparatus for determining the analyte concentration in Patent Document 1 below is known. Patent Document 1 discloses that a color reaction on a test paper is measured by dividing it into a plurality of regions, and a measurement value in a region where the specimen is not sufficiently developed is not used for calculating the component concentration.

JP 2004-163393 A

However, in the above-described apparatus for determining the analyte concentration of Patent Document 1, although the measurement value of the region where the specimen is not sufficiently developed on the test paper is excluded, the difference in the start time of coloration in each region is described. Not considered. Therefore, when there is a difference in the start time of coloration in each region, depending on the region, there is a possibility that the color is measured and the component concentration is calculated in a state where the color reaction does not proceed sufficiently. As a result, the accuracy of the calculation result of the component concentration may be insufficient.

The present invention has been made to solve the above-described problems. Accordingly, an object of the present invention is to provide a component measuring apparatus and a component measuring method capable of accurately calculating the concentration of the specific component in the sample even when the developing speed of the sample on the test paper changes.

The above object of the present invention is achieved by the following.

The component measurement apparatus of the present invention is a component measurement apparatus that measures the concentration of a component based on the degree of color development of a reagent that reacts with a component contained in a specimen, and includes an irradiation unit, a detection unit, a component concentration calculation unit, Have The irradiation means irradiates light onto the test piece to which the specimen is attached. The detection means detects the reflected light reflected by a plurality of different regions on the test piece. The component concentration calculation means calculates the concentration of the component contained in the sample based on the intensity of the reflected light at the end time after a predetermined time has elapsed from the start time at which the sample has infiltrated and started coloring in a plurality of different regions.

The component measurement method of the present invention is a component measurement method for measuring the concentration of a component based on the degree of color development of a reagent that reacts with a component contained in a sample, and starting irradiation of light on a test piece to which the sample is attached. And a step of starting detection of the reflected light respectively reflected in a plurality of different areas on the test piece, and a reflection of an end time after a predetermined time has elapsed from the start time when the specimen invaded and started coloring in the different areas. Calculating the concentration of the component contained in the specimen based on the light intensity.

According to the present invention, it is possible to prevent the change in the development speed from affecting the calculation of the component concentration of the specimen by aligning the coloration start times in a plurality of different regions on the test piece. Therefore, the component concentration of the specimen can be calculated with high accuracy. Further, even if a development failure occurs in a part of the area on the test piece, the measurement can be continued and the measurement value can be calculated.

It is a schematic block diagram for demonstrating the blood component analyzer in the 1st Embodiment of this invention. It is a flowchart for demonstrating the measurement processing procedure of the glucose concentration by the component measuring apparatus of the 1st Embodiment of this invention. 3A is a schematic diagram for illustrating the development of blood spotted on a test paper, and FIG. 3B is a diagram for explaining a reflectance curve in a region A68 of FIG. 3A. It is. It is a flowchart for demonstrating in more detail step S103 of the flowchart shown in FIG. It is a figure for demonstrating the processing content in each step of the flowchart of FIG. It is a figure for demonstrating that the magnitude | size of a reflectance varies with an area | region. FIGS. 7A and 7B are diagrams for explaining a method of setting the upper limit value and the lower limit value of the reflectance. It is a flowchart for demonstrating the procedure which calculates the glucose level contained in the blood in the 2nd Embodiment of this invention. It is a figure explaining the processing content in each step of the flowchart shown in FIG. It is a figure for demonstrating the procedure which calculates the glucose level contained in the blood in the 3rd Embodiment of this invention with the processing content in each step.

Hereinafter, an embodiment of a component measuring apparatus of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals are used for the same members.

(First embodiment)
FIG. 1 is a schematic block diagram for explaining a component measuring apparatus according to the first embodiment of the present invention. The component measuring apparatus of this embodiment arranges the coloration start times in a plurality of different regions on the test piece. In addition, below, the principal part of the component measuring apparatus of this embodiment is demonstrated, and description is abbreviate | omitted about the part similar to the conventional component measuring apparatus.

In the present embodiment, a colorimetric blood glucose measuring device that measures a blood glucose level based on a color change (coloring) of a reagent that reacts with glucose contained in blood will be described as an example. In the colorimetric blood glucose measurement device, the color of the reagent that reacts with blood by irradiating light on the opposite side of the blood adhering surface of the test paper (test strip) to which blood has adhered and receiving the reflected light from the test paper Based on the above, the concentration of glucose contained in the blood is measured. The test paper contains a reagent that develops color by reacting with glucose in the blood, and the color development of the test paper increases as the glucose concentration increases. The glucose concentration is measured by utilizing the change in the amount of light received due to the difference in the color density. For measurement of the glucose concentration, light having a wavelength of 620 to 640 nm (red light) is preferably used.

In the present embodiment, the hematocrit value for correcting the measured glucose concentration is also measured. The hematocrit value is measured based on the concentration of hemoglobin in the blood. For measuring the hematocrit value, light having a wavelength of 510 to 540 nm (green light) is preferably used.

In this embodiment, red light and green light are alternately and periodically irradiated on the test paper to measure the glucose concentration and the hematocrit value. That is, in this embodiment, the glucose concentration and the hematocrit value are alternately measured in a time division manner using two wavelengths of light. Since the hematocrit value can be measured in the same manner as when measuring the glucose concentration, the following description focuses on the measurement of the glucose concentration. Further, the method for calculating the glucose concentration and the hematocrit value from the reflectance of light of each wavelength is the same as the conventional method, and thus the description thereof is omitted.

As shown in FIG. 1, the component measurement device (colorimetric blood glucose measurement device) 100 according to the present embodiment includes an attachment unit 110, a light source unit 120, a light emission drive unit 130, a detection unit 140, a signal processing unit 150, an operation unit 160, A display unit 170 and a calculation control unit 180 are included. Hereafter, each component shown in FIG. 1 is demonstrated in order.

In the component measuring apparatus 100 of the present embodiment, the measurement is started by detecting that blood has infiltrated into the test paper 111 and the reflectance of the test paper 111 has changed significantly, and based on the reflectivity after a predetermined time from the start time. To calculate the blood sugar level. Since the test paper 111 before blood is attached is a color close to white, the reflectance is large. On the other hand, the test paper 111 after the blood is adhered develops color and the reflectance decreases as the reaction between glucose and the reagent proceeds. For this reason, as the reflectance when calculating the blood sugar level, it is desirable to adopt the reflectance when the reaction rate between the glucose and the reagent approaches the state where the reaction has been completed and the reduction rate of the reflectance is within a predetermined value. The test paper 111 is detachably attached to the attachment unit 110 after being held in an appropriate case. For example, the mounting unit 110 is provided in a housing (not shown) of the component measuring apparatus 100. Thereby, the positional relationship between the test paper 111, the light source unit 120, and the detection unit 140 is determined.

The light source unit 120 is a light source that irradiates light onto the test paper 111 as an irradiation means. The light source unit 120 is attached to the housing of the component measuring apparatus 100 so that the light emitting surface thereof faces the direction of the test paper 111. Irradiation light from the light source unit 120 is collected by a lens (not shown) and irradiates the entire test paper 111. The light source unit 120 includes a light emitting diode (LED) that emits light within a wavelength range of light absorbed by the color of the test paper 111, for example, a wavelength of about 500 to 720 nm.

In the present embodiment, the light source unit 120 includes a red light emitting diode and a green light emitting diode. The red light-emitting diode emits red light and is used to measure the blood glucose concentration in accordance with the amount of dye produced by the reaction between glucose and the coloring reagent. The green light emitting diode emits green light and is used to measure the hematocrit value based on the amount of hemoglobin in the blood. The red light emitting diode and the green light emitting diode may be arranged close to each other as separate elements, or may be integrally configured as one element.

The light emission drive unit 130 is a drive circuit that supplies a drive signal to the light source unit 120. More specifically, the light emission driving unit 130 supplies a pulse signal having a predetermined pulse width, intensity, and cycle to the light source unit 120 based on an instruction from the arithmetic control unit 180. The light source unit 120 repeatedly emits light for the duration of this pulse width in accordance with the supplied pulse signal, and turns off until the next pulse signal rises. The pulse width is generally in the range of 10 to 1000 μs, preferably about 120 μs. The period is about 1 ms to 10 ms, preferably about 2 ms for each of red and green. Note that red light and green light are preferably emitted alternately. The pulse width, intensity, and period can be appropriately changed according to the design conditions of other components.

The detection unit 140 detects, as detection means, the reflected light that is reflected by a plurality of different regions on the test paper 111 and converts it into an electrical signal. The detection unit 140 is attached to the housing of the component measurement apparatus 100 so that the light receiving surface thereof faces the test paper 111.

The detection unit 140 includes a plurality of light detection elements (not shown) that detect reflected light corresponding to a plurality of different regions on the test paper 111, respectively. The light detection elements are sensitive to the wavelength of light absorbed by the color reaction of the test paper 111 and are preferably arranged in a line or matrix on the light receiving surface of the detection unit 140. In addition, the arrangement form of the light detection elements is not limited to the form arranged in a line or a matrix, and other arrangement forms may be used.

Each light detection element includes at least one pixel which is a minimum unit having a function of detecting light. Therefore, in the light detection element having such a configuration, reflected light from a plurality of different regions on the test paper 111 is detected by at least one pixel of the corresponding light detection element. In this embodiment, an image sensor is employed as the plurality of light detection elements. The image sensor is, for example, a CCD sensor or a CMOS sensor in which a plurality of pixels are arranged in a matrix.

Also, the irradiation range of the light source unit 120 and the field of view (detection range) of the detection unit 140 do not necessarily need to match. For example, even when the light source unit 120 irradiates the entire surface of the test paper 111, the detection unit 140 may be configured to detect reflected light from a specific area on the test paper 111.

In the present embodiment, the plurality of light detection elements of the detection unit 140 detect reflected light corresponding to a plurality of different regions on the test paper 111, respectively. Therefore, the distance that blood is spread on the test paper 111 in one region is shorter than that of the test paper 111 as a whole, and the apparent development speed in the detection range increases. That is, the blood development time is relatively shortened.

The signal processing unit 150 performs signal processing on the electrical signal output from the detection unit 140. The signal processing unit 150 includes a sample and hold circuit, an amplifier circuit, and an A / D converter. The electrical signal output from the detection unit 140 is periodically sampled by a sample and hold circuit, amplified to a predetermined signal level by an amplifier circuit, converted from an analog signal to a digital signal by an A / D converter, and used as image data. It is stored in the memory of the arithmetic control unit 180.

The operation unit 160 transmits an instruction from the operator to the calculation control unit 180. The operation unit 160 has, for example, a push button switch, and is attached to the casing of the component measuring apparatus 100. The operator gives instructions to start / stop the component measuring apparatus 100 and display the measurement result via the operation unit 160.

The display unit 170 displays the blood sugar level calculated by the calculation control unit 180. The display unit 170 has a liquid crystal display panel, for example, and is attached to the housing of the component measuring apparatus 100.

The calculation control unit 180 performs overall control of the component measuring apparatus 100 and calculation of blood glucose level. More specifically, the arithmetic control unit 180 includes peripheral circuits including, for example, a CPU, a memory, a communication circuit, and the like, and includes a light source unit 120, a light emission drive unit 130, a detection unit 140, a signal processing unit 150, and an operation unit 160. And the display unit 170 are electrically connected. The arithmetic control unit 180 executes blood glucose level measurement processing according to a predetermined procedure in response to an instruction from the operator input via the operation unit 160.

The arithmetic control unit 180 uses the image data stored in the memory as the component concentration calculation means to calculate the reflectance of the test paper 111 before and after attaching blood to the test paper 111, and for each of the test papers 111. Time measurement is started by detecting that blood has infiltrated the region. After a predetermined time has elapsed, the glucose concentration is calculated using the correspondence between the reflectance and the glucose concentration. A timer (not shown) is used for measuring the predetermined time. The correspondence between the reflectance and the glucose concentration is stored in advance in a non-volatile memory such as a ROM as a lookup table, or is calculated from a relational expression between the reflectance and the glucose concentration. The calculated glucose concentration is corrected using the hematocrit value and output to the display unit 170 as a blood glucose level.

The measurement processing procedure by which the component measuring apparatus 100 measures the glucose concentration is stored in advance as a program in a nonvolatile memory such as a ROM of the arithmetic control unit 180, and the CPU sequentially executes the program. When the component measuring apparatus 100 is activated, the arithmetic control unit 180 instructs the light emission driving unit 130 to output a predetermined pulse signal, and the signal processed by the signal processing unit 150 is used as image data in a RAM or the like. Instructs to store in volatile memory. Hereinafter, the measurement processing procedure of the component measuring apparatus 100 will be described with reference to FIGS.

FIG. 2 is a flowchart for explaining the procedure for measuring the glucose concentration by the component measuring apparatus according to the first embodiment of the present invention. 3A is a schematic diagram for illustrating the development of blood spotted on the test paper, and FIG. 3B is a diagram for explaining the reflectance curve in the region A68 of FIG. 3A. FIG. Note that in FIG. 3B, the horizontal axis represents time, and the vertical axis represents reflectance.

As shown in FIG. 2, first, light irradiation is started on the test paper 111 (step S101). Specifically, the light source unit 120 emits light in pulses, and irradiation of light onto the test paper 111 is started. The light source unit 120 emits pulses in order to reduce the influence of ambient light incident on the component measuring apparatus 100 by using the difference between the signal level during light emission and the signal level during extinction for measurement. is there. In addition, there is an effect of reducing power consumption by causing the light source unit 120 to emit light intermittently.

Next, detection of reflected light from the test paper 111 is started (step S102). In the present embodiment, the detection unit 140 detects the reflected light that is reflected by a plurality of different regions on the test paper 111. Specifically, as shown in FIG. 3A, for example, the test paper 111 is divided into 10 × 10 = 100 regions A1 to A100, and the reflected light reflected in each region An corresponds to the detection unit 140. It detects with a photon detection element (not shown). Note that the number of regions for separating the test paper 111 can be set as appropriate in consideration of the calculation accuracy of the glucose concentration, the calculation processing time, and the number of pixels of the detection unit 140.

Note that the arithmetic control unit 180 can calculate the distance between the areas based on the size of the test paper 111 and the number of areas separating the test paper 111. Further, the blood development speed on the test paper 111 can be calculated from the distance between the regions and the difference in the coloration speed. Since the deployment speed depends on the hematocrit value, it can be used as information for estimating the hematocrit value.

When the component measuring apparatus 100 is activated, upon receiving an instruction from the arithmetic control unit 180, the detection unit 140 starts detecting the reflected light reflected by the areas A1 to A100 on the test paper 111 at time t0. At this time, since blood is not spotted on the test paper 111, the reflected light of the test paper 111 whose surface is white is detected. Here, the reflectance of the test paper 111 is 1. In the present embodiment, the reflectance is calculated based on the intensity of the reflected light at the time t0.

Thereafter, blood is spotted on the spotting area X on the test paper 111 at time t1. The spotted blood spreads on the test paper 111 and reaches the development area Y at time t2, and reaches the development area Z at time t3. In this embodiment, it is assumed that it takes about 1 second for the spotted blood to spread over the entire test paper 111, and about 8 seconds for the color reaction to stabilize. The size of the test paper 111 is about 2 to 6 mm on a side.

In the example of blood development shown in FIG. 3A, when blood spreads on the test paper 111, the time for the blood to reach differs depending on the position on the test paper 111. The longer the distance from the spotting area X, the longer it takes for blood to infiltrate and reach it. Here, the blood development speed varies depending on the temperature and viscosity of the blood, the porosity and hole diameter of the test paper 111, the amount of reagent applied, and the like. These causes lead to a measurement error when the reflected light is detected using the test paper as one region.

On the other hand, the color reaction is started after blood arrives, and the reaction rate of the color reaction is considered to be constant under the same conditions. Therefore, it is considered that the temporal change in the reflectance of the test paper 111 detected by the detection unit 140 strongly depends on the blood development speed.

For example, in the region A68 of FIG. 3A, the color reaction does not occur because the blood has not yet reached from time t0 to t2. Therefore, as shown in FIG. 3B, the reflectance of the test paper 111 is maintained at about 1 until time t2. On the other hand, after the time t2, the color reaction proceeds because blood develops in A68. Accordingly, the reflectance of the region A68 starts to decrease. In the following, a curve showing the temporal change in reflectance as shown in FIG. 3B is referred to as a reflectance curve.

In the present embodiment, the arithmetic control unit 180 calculates the reflectance curve in the areas A1 to A100 based on the image data stored in the RAM. When the light detection element of the detection unit 140 includes a plurality of pixels, for example, a value obtained by averaging the data of the plurality of pixels can be used as a representative value to calculate the reflectance curve.

As described above, in a plurality of different regions A1 to A100 on the test paper 111, the time when the color of the reagent starts to change, that is, the time when the color reaction is started depends on the blood development speed on the test paper 111. Change.

Next, returning to FIG. 2 again, the concentration of glucose contained in the blood is calculated (step S103). In the present embodiment, in the areas A1 to A100 on the test paper 111, the glucose concentration contained in the blood is calculated based on the reflectance at the end time t3 after a predetermined time has elapsed from the start time t2 when the color was detected. The arithmetic control unit 180 calculates the blood glucose level based on the measured glucose concentration, the display unit 170 displays the blood glucose level, and the process is terminated. The reflectance detected before the start time t2 (for example, t1) can be used for correcting the baseline.

Hereinafter, the procedure for calculating the concentration of glucose contained in blood will be described in more detail with reference to FIGS. FIG. 4 is a flowchart for explaining step S103 of the flowchart shown in FIG. 2 in more detail, and FIG. 5 is a diagram for explaining the processing contents in each step of the flowchart of FIG. FIG. 6 is a diagram for explaining that the magnitude of the reflectance varies depending on the region. FIGS. 7A and 7B are diagrams for explaining a method of setting the upper limit value and the lower limit value of the reflectance.

As shown in FIGS. 4 and 5, first, the coloration start time is recognized for each region (step S201). Specifically, the color development start time is recognized for the reflectance curves in the regions A1 to A100 (hereinafter referred to as reflectance curves C1 to C100). In FIG. 5, S1 to S100 indicate the light detection elements of the detection unit 140.

Next, the color start times of all areas are aligned (step S202). Specifically, the start time when the coloration of the reflectance curves C1 to C100 is detected is aligned with the reference time. As the reference time, a predetermined reference time may be set, or the start time of any one of the reflectance curves C1 to C100 may be set. For example, as shown in FIG. 5, the coloration start times of the reflectance curves C1 to C99 can be aligned with the coloration start time of the reflectance curve C100.

Thus, by aligning the coloration start times in the reflectance curves C1 to C100 with the reference time, the influence of the development speed on the glucose concentration calculation can be canceled. Therefore, the calculation accuracy of the glucose concentration is improved.

Note that coloration in a specific region on the test paper 111 may not be started due to a local abnormality of the test paper 111, a lack of blood volume, or the like. For example, in FIG. 5, the reflectance curve Cm of the region Am has not started to be colored within the measurement time. In addition, the start of coloring may be extremely early or late. In such a case, in order to prevent the calculation of the glucose concentration from being affected, the reflectance curve in the region is not used for the subsequent processing. The determination when the start of coloration becomes extremely early or late is made by comparing the start time of coloration with a predetermined first upper limit value and a first lower limit value. When the start time of coloration is within the range between the first upper limit value and the first lower limit value in a certain area, the reflectance curve in that area is used for the subsequent processing. On the other hand, when the coloration start time is not within the range between the first upper limit value and the first lower limit value, the reflectance curve in the region is not used for the subsequent processing.

In addition, as shown in FIG. 6, the magnitude of the reflectance after the start of coloring may vary depending on the area on the test paper 111. The reflectance curve Cn ′ is a reflectance curve in the region An ′, and the reflectance curve Cn ″ is a reflectance curve in the region An ″. Factors that cause variations in the magnitude of the reflectance include uneven application of the reagent on the test paper 111, a difference in surface roughness and shape of the test paper 111, and the like. Alternatively, when the reflectance increases as in the region An ′, it may be considered that blood has infiltrated only a part of the region An ′.

In this embodiment, since the variation in the reflectivity affects the calculation of the glucose concentration, in the present embodiment, a predetermined second upper limit value and second lower limit value are set for the reflectivity size. The reflectance curve that is set and deviates from the range of the second upper limit value and the second lower limit value is not used for the subsequent processing.

Specifically, the second upper limit value and the second lower limit value are set based on the frequency distribution of the number of pixels with respect to the reflectance at time t3 after the start of coloring. As shown in FIG. 7A, the frequency distribution of the number of pixels with respect to the reflectance usually has a first peak P1 and a second peak P2. The first peak P1 represents the maximum value of the number of pixels in which the reflectance has decreased due to the development of blood on the test paper 111 and the occurrence of coloration. On the other hand, the second peak P2 represents the maximum value of the number of pixels having high reflectivity because blood is not spread on the test paper 111.

In the present embodiment, the reflectance corresponding to a predetermined number of pixels when the number of pixels of the first peak P1 is 100% is set as the second upper limit value and the second lower limit value. For example, as shown in FIG. 7A, the reflectances RU and RL corresponding to 90% of the number of pixels of the first peak P1 are set as the second upper limit value and the second lower limit value, respectively. Can do. When the second upper limit value and the second lower limit value are set as described above, only the reflectance curve whose reflectance is within the range between the upper limit value RU and the lower limit value RL is used in the subsequent processing.

Further, as shown in FIG. 7B, the second upper limit value (N) is included so that N pixels are included between the reflectances RL ′ and RU ′ around the reflectance corresponding to the first peak P1. RU ′) and the second lower limit (RL ′) may be determined.

Next, returning to FIG. 4 again, the reflectance curves of the respective regions are synthesized (step S203). In the present embodiment, among the reflectance curves C1 to C100, the coloration start time is within the range of the first upper limit value and the first lower limit value, and the reflectance after the start of coloration is the second upper limit value. Then, the reflectance curves within the range of the second lower limit value are combined at the reference time and synthesized to calculate a synthesized reflectance curve CS. In this way, by combining the results of measuring a plurality of different regions, it becomes difficult to be affected by the amount of reagent applied to the test paper 111 and the variation in the structure of the test paper 111.

Next, the glucose concentration is calculated (step S204). The glucose concentration is calculated using the combined reflectance curve CS calculated in step S203.

As described above, in the present embodiment, the color change start time of the reflectance curve in a plurality of different regions on the test paper 111 is aligned with the reference time, and then the combined reflectance curve obtained by combining the reflectance curves of the respective regions is used. Based on this, the glucose concentration is calculated.

As described above, the component measuring apparatus 100 according to this embodiment has the following effects.

(A) According to the component measuring apparatus 100 of the present embodiment, the change in the development speed has an influence on the calculation of the glucose concentration by aligning the start times of coloration in a plurality of different regions on the test paper 111 with the reference time. Can be prevented. Therefore, the glucose concentration can be calculated with high accuracy. Further, even if a development failure occurs in a part of the area on the test paper 111, the measurement can be continued and the measurement value can be calculated.

(B) By synthesizing the results of measuring a plurality of different regions, it becomes difficult to be affected by variations in the amount of reagent applied to the test paper 111 and the structure of the reagent carrier.

(C) The development speed on the test paper 111 can be calculated from the distance between the areas and the difference in the coloration speed.

(D) Within the range of the detection visual field of the detection unit 140, the glucose concentration can be calculated with high accuracy regardless of the region of the test paper 111 where blood development starts or the blood development range is different.

(Second Embodiment)
In the first embodiment, after aligning the start time of coloration of the reflectance curve in a plurality of different regions on the test paper with the reference time, the glucose concentration is based on the combined reflectance curve obtained by synthesizing the reflectance curve of each region. The calculation of the above has been described. In the second embodiment of the present invention, calculation of the glucose concentration for each region on the test paper and averaging the glucose concentration in each region to calculate the final glucose concentration will be described. In the following description, the description of the same configuration as in the first embodiment is omitted.

Hereinafter, the component measuring apparatus of this embodiment will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart for explaining the procedure for calculating the concentration of glucose contained in blood in the second embodiment of the present invention, and FIG. 9 is a diagram for explaining the processing contents in each step of the flowchart shown in FIG. is there.

As shown in FIGS. 8 and 9, first, the coloration start time is recognized for each region (step S301). The start time of coloration is recognized for the reflectance curves C1 to C100 of a plurality of different areas A1 to A100 on the test paper 111. As in the first embodiment, those having an abnormal reflectance curve are not used for the subsequent processing.

Next, the glucose concentration is calculated for each region (step S302). Specifically, in a plurality of different regions on the test paper 111, the glucose concentration contained in the blood is calculated based on the reflectance at the end time after a predetermined time has elapsed from the coloration start time recognized in step S301.

Next, the glucose concentration in each region is averaged (step S303). Specifically, the final glucose concentration is calculated by averaging the glucose concentration of each region calculated in step S302.

As described above, in this embodiment, the glucose concentration is calculated in each of a plurality of different regions on the test paper 111, and the final glucose concentration is calculated by averaging the glucose concentration in each region. In any region, the glucose concentration in the blood is calculated based on the reflectance at the end time after a predetermined time has elapsed from the coloration start time, so the difference in coloration start time between the regions is the calculation of the glucose concentration. It does not affect. In this embodiment, by calculating the glucose concentration for each region, the color start times in each region are substantially aligned.

(E) Since the glucose concentration is calculated in each of a plurality of different regions on the test paper 111 and the glucose concentration in each region is averaged to calculate the final glucose concentration, the processing load accompanying the calculation of the glucose concentration Can be reduced.

(Third embodiment)
In the first and second embodiments, it has been described that measurement of a plurality of wavelengths is performed in a time division manner. In the third embodiment, it will be described that multi-color light is used as a light source, and the light detection element includes a band-pass filter that passes light of a specific wavelength, thereby performing measurement of a plurality of wavelengths. In the following description, portions different from those of the second embodiment will be mainly described, and description of the same configuration as that of the second embodiment will be omitted.

In the present embodiment, the light source unit 120 emits multicolor light (for example, white light). The light source unit 120 includes, for example, a white light emitting diode. The arithmetic control unit 180 instructs the light emission driving unit 130 to output a predetermined pulse signal. However, in the present embodiment, the detection unit 140 separates light of a specific wavelength used for measurement with a bandpass filter. Therefore, the arithmetic control unit 180 does not need to perform timing control for irradiating and detecting light of different wavelengths in a time division manner.

Hereinafter, the component measuring apparatus according to the present embodiment will be described with reference to FIG. FIG. 10 is a diagram for explaining the procedure for calculating the glucose concentration contained in blood in the third embodiment of the present invention together with the processing contents at each step.

As shown in FIG. 10, the detection unit 140 includes light detection elements S1R, S1G to S100R, and S100G that detect reflected light from a plurality of different areas A1 to A100 on the test paper 111. The light detection element S1R includes a red band-pass filter that transmits only red light on the pixel, and detects red light in the region A1. The light detection element S1G includes a green band-pass filter that transmits only green light on the pixel, and detects the green light in the region A1. In addition, it is preferable that the light detection elements S1R and S1G are configured so that pixels including a red bandpass filter and pixels including a green bandpass filter are arranged in a grid pattern.

In the component measuring apparatus 100 having such a configuration, the coloration start time is first recognized for each region, and then the glucose concentration and the hematocrit value are calculated for each region. Then, the glucose concentration is corrected with the hematocrit value in each region. Then, the final glucose concentration is calculated by averaging the glucose concentration in each region.

In addition to the effects of the second embodiment, the component measuring apparatus 100 of the present embodiment described as described above has the following effects.

(F) Since the detection unit 140 separates light of a specific wavelength used for measurement by a bandpass filter, timing control for irradiating and detecting light of different wavelengths in a time division manner can be omitted.

As described above, in the embodiment, the component measuring apparatus of the present invention has been described. However, it goes without saying that the present invention can be appropriately added, modified, and omitted by those skilled in the art within the scope of the technical idea.

For example, in the first to third embodiments, the glucose concentration was calculated based on the reflectance calculated from the intensity of the reflected light reflected from the test piece. However, this invention can also be set as the structure which calculates glucose concentration based on the transmitted light which permeate | transmitted the test piece.

In addition, the present invention can be suitably used to calculate a blood glucose level, but it can of course be widely used in the field of measuring the component concentration of a specimen by quantitatively measuring the amount of transmitted light or reflected light. It is. For example, the present invention can also be configured to measure the concentration of specific components in body fluids, such as cholesterol in blood, uric acid, glucose in urine, hemoglobin, and the like.

Furthermore, this application is based on Japanese Patent Application No. 2011-228956 filed on October 18, 2011, and the disclosures thereof are referred to and incorporated as a whole.

100 component measuring device,
110 wearing part,
111 test paper (test piece),
120 light source part (irradiation means),
130 light emission drive unit,
140 detector (detector),
150 signal processing unit,
160 operation unit,
170 display unit,
180 Calculation control unit (component concentration calculation means).

Claims

A component measuring device that measures the concentration of the component based on the degree of color development of the reagent that reacts with the component contained in the specimen,
Irradiating means for irradiating light onto a test piece to which the specimen is attached;
Detecting means for detecting reflected light respectively reflected by a plurality of different regions on the test piece;
Component concentration calculation means for calculating the concentration of the component contained in the sample based on the intensity of the reflected light at an end time after a predetermined time has elapsed from the start time when the sample infiltrated and coloration started in the plurality of different regions When,
A component measuring apparatus comprising:
The component concentration calculation means calculates a reflectance curve representing a temporal change in reflectance of the test piece from the start time to the end time in the plurality of different regions, and then calculates the plurality of different regions. The component measurement apparatus according to claim 1, wherein the reflectance curve is synthesized based on the start time, and the concentration of the component contained in the specimen is calculated based on the synthesized reflectance curve.
The component concentration calculation unit calculates a reflectance curve of the test piece from the start time to the end time in the plurality of different regions, and the concentration of the component in the plurality of different regions based on the reflectance curve. 2. The method according to claim 1, further comprising: calculating an average value of the concentration of the component for the plurality of different regions and calculating a concentration of the component included in the specimen based on the average value. Component measuring device.
The irradiation means irradiates light of a specific wavelength,
The component measuring apparatus according to any one of claims 1 to 3, wherein the detecting means detects reflected light of the specific wavelength.
The irradiation unit irradiates the plurality of different regions with polychromatic light including a specific wavelength,
The component measuring apparatus according to any one of claims 1 to 3, wherein the detection unit includes a band-pass filter that transmits the specific wavelength, and detects reflected light of the specific wavelength.
The component concentration calculation means sets an upper limit value and a lower limit value for the reflectivity after the start time of the reflectivity curve, and the reflectivity is within the range between the upper limit value and the lower limit value. While the rate curve is used to calculate the concentration of the component contained in the specimen, when the reflectance is not within the range of the upper limit value and the lower limit value, the reflectance curve is used to calculate the concentration of the component contained in the specimen. 6. The component measuring apparatus according to claim 2, wherein the component measuring apparatus is not used for calculation.
A component measurement method for measuring the concentration of the component based on the degree of color development of the reagent that reacts with the component contained in the specimen,
Initiating light irradiation on the test specimen to which the specimen adheres;
Initiating detection of reflected light respectively reflected at a plurality of different regions on the specimen;
Calculating a concentration of a component contained in the specimen based on an intensity of the reflected light at an end time after a predetermined time has elapsed from a start time at which the specimen has infiltrated and coloration has started in the plurality of different regions;
The component measuring method characterized by having.