JP2008232664A - Measuring method of blood component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein, when calculating a characteristic value of a blood component in the state where blood spot-contacted on a test piece is not diffused sufficiently in a reaction domain on the test piece, a wrong characteristic value is calculated, in a medical diagnosis apparatus. <P>SOLUTION: In the medical diagnosis apparatus having a spot contact detection means for detecting a blood quantity spot-contacted on the test piece, a light source for irradiating the blood on the reaction domain on the test piece with excitation light, a photodetection means for detecting fluorescence emitted from the excitation light and acquiring it as a measured value of a fluorescence quantity, and an operation processing means for calculating the characteristic value of the blood component from the acquired measured value of the fluorescence quantity, a fluorescence value just after spot contact of the blood is compared with a fluorescence value after elapse of a prescribed time after performing spot contact, while monitoring a spot-contact quantity of the blood, and it is determined whether the blood is diffused sufficiently over the reaction domain on the test piece or not based on the comparison result. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a blood component measurement method, and more particularly to a method for detecting the amount of blood spotted using a test piece containing a luminescent material or other reagent that generates a signal when a characteristic reaction of the blood component occurs. It is.

Hereinafter, a conventional method for detecting the amount of blood spotted will be described with reference to FIGS.
FIG. 3 is a configuration example of the test piece 20, (a) is a top view of the test piece, and (b) is a view of a cross section of the thin solid line XY as viewed from the A direction.

  The test piece 20 has a spotting hole 22 for spotting blood. Further, as shown in FIG. 3B, a reaction region 21 and a pair of conductive plates 23 coated with a reagent that generates a light emitter or other signal when a characteristic reaction occurs with a blood component are formed. , 24. The conduction plates 23 and 24 are provided on the lower surface of the test piece 20 in a non-contact state.

  When blood is spotted on the spotting hole 22 on the upper surface of the test piece 20 with respect to the test piece 20 having such a configuration, the blood is diffused in the reaction region 21 and mixed with the reagent. At this time, the amount of spotted blood is detected as follows.

FIG. 4 is a diagram illustrating a configuration example of a spotting detection unit of the conventional medical diagnostic device 100.
A medical diagnostic apparatus 100 shown in FIG. 4 includes an A / D converter 101 that detects changes in current in the reaction region 21 of the test piece 20 by bringing the electrodes 31 and 32 into contact with the conductive plates 23 and 24 of the test piece 20; And a microcomputer 102 that controls the A / D converter 101 that acquires the amount of blood spotted from the amount of current change detected by A / D conversion.

  Since the electrode 31 is connected to the ground, and the electrode 32 is connected to the power supply VDD via the resistor R1, the voltage applied to the electrode 32 in a state where blood is not deposited on the test piece 20, that is, A The input to the / D converter 101 is the power supply voltage VDD. Further, the electrodes 31 and 32 are configured to come into contact with the conduction plates 23 and 24 when the test piece 20 is mounted on the medical diagnostic device 100, respectively.

  FIG. 5A is a diagram illustrating a configuration example of a spotting detection unit of the medical diagnostic device 100 in the blood spotting state, and FIG. 5B is a schematic diagram of the spotting detection unit. Is a profile of the voltage applied to the electrode of the spotting detection unit.

  As shown in FIG. 5A, when the test piece 20 is mounted on the medical diagnostic device 100 and the blood 10 is spotted on the test piece 20, the power supply VDD-resistance R1-electrode 32-conduction plate 24-blood. A current flows between 10-conductive plate 23-electrode 31-ground GND. That is, as shown in FIG. 5B, when the blood 10 is spotted on the test piece 20, the voltage Vi obtained by dividing the power supply voltage VDD by the resistance R1 and the resistance Rb of the blood 10 becomes A / It is input to the D converter 51. As shown in the voltage profile 35 of FIG. 6, the voltage applied to the electrode 32 is significantly reduced for about 20 seconds from the time T0 immediately after the blood 10 is spotted. Thereafter, if the amount of blood deposited is sufficient, the voltage input to the A / D converter 51 maintains its voltage drop state as shown in the voltage profile 36 of FIG. When the amount of worn blood is insufficient, the voltage input to the A / D converter 51 tends to increase as time passes, as shown in the voltage profile 37 of FIG.

  Utilizing such characteristics, the conventional medical diagnostic apparatus 100 performs A / D conversion on the voltage applied to the electrode 32 every predetermined time, for example, every 10 seconds, based on the time when the spotting of the blood 10 is detected. Using the method of comparing the acquired spot value and the determination value Vo for determining whether or not the blood spot amount is sufficient, the blood spot detection process is performed. ing.

  When the blood spotting detection process is performed to detect that the amount of spotting is sufficient, the characteristic value of the blood component is then calculated.

FIG. 7 is a diagram illustrating a configuration example of a characteristic value calculation unit of a blood component of a conventional medical diagnostic device 200.
In addition to the configuration shown in FIG. 4, the conventional medical diagnostic device 200 shown in FIG. 7 projects a light source 203 that emits light 204, and a projection that projects the irradiation light 204 of the light source 203 onto the reaction region 21 of the test piece 20. An optical filter 205, a driver 202 that controls the light source 203, a lens 207 that collects fluorescence of blood 10 generated by the irradiation light 204, a light receiving filter 208 that receives the light collected by the lens 207, and a light receiving filter And a photodiode 209 that detects the amount of received light 208 and converts the amount of received light into an electric signal 210. The A / D converter 101 acquires a fluorescence value based on the electrical signal obtained by the photodiode 209. Further, the microcomputer 102 calculates the characteristic value of the blood component based on the fluorescence value acquired by the A / D converter 211.

Below, the blood component measuring method by the conventional medical diagnostic apparatus 200 is demonstrated using FIG.
FIG. 8 is a flowchart showing a blood component measurement method performed by the conventional medical diagnostic device 200.

  First, after the user attaches the test piece 20 to the medical diagnostic device 200, blood spotting detection processing is performed until the user spots the blood 10 on the test piece 20 (steps S21 to S22 are repeated). .

  When the user drops the blood 10 on the test piece 20, for example, the user waits for 20 seconds after the spotting until the blood 10 is sufficiently diffused in the reaction region 21 and the characteristic reaction of the blood component starts (step S23).

  Thereafter, spotting detection processing of blood 10 is performed every predetermined time, for example, every 10 seconds (step S24), and it is determined whether or not the amount of spotting of blood 10 is sufficient (step S25).

  As a result of the determination, if it is determined that the amount of spotted blood 10 is insufficient, an error process is performed (step S27), and the measurement process ends abnormally.

  On the other hand, as a result of the determination, if it is determined that the amount of spotted blood 10 is sufficient, a fluorescence detection process is performed (step S26). That is, the irradiation light 204 from the light source 203 is applied to the blood 10 in the reaction region 21 of the test piece 20. The blood 10 is excited by the irradiation light 204 from the light source 203 and emits fluorescence 206. The light quantity of the fluorescent light 206 is detected by the photodiode 209 and converted into an electric signal 210, and a fluorescent value is acquired from the electric signal 210.

  Then, it is determined whether or not the characteristic value of the blood component can be calculated from the fluorescence value (fluorescence amount) acquired every predetermined time (step S28). If the characteristic value of the blood component can be calculated, the measurement process is terminated normally. Otherwise, the process returns to step S23.

As described above, in the conventional blood component measurement method, during the measurement, blood spotting detection processing is performed every predetermined time to determine whether or not the blood spotting amount is sufficient. If it is determined that the wearing amount is sufficient, the characteristic value of the blood component is calculated, and if it is determined that the blood spotting amount is insufficient, the measurement process is terminated abnormally. (For example, refer to Patent Document 1.)
Special table hei 8-508094 (Fig. 3)

  However, in the above conventional blood component measurement method, the amount of spotted blood 10 can be determined using the voltage change (shown in FIG. 6) generated by the resistance change of blood 10. It is not determined whether or not the spotted blood 10 has diffused to mix with the reagent in the reaction region 21. Therefore, even if the user deposits a sufficient blood volume on the test piece 20 and the voltage change is a normal profile as shown in the voltage profile 36 of FIG. 6, for example, the membrane in the reaction region 21 of the test piece 20 If there is a problem with the test piece 20 such that blood does not penetrate into the reaction area 21 and the spotted blood 10 has not diffused in the reaction region 21, the blood component must be measured accurately as shown below. Can not be.

  FIG. 9 is a schematic diagram showing the diffusion state of blood in the reaction region of the test piece, (a) is a schematic diagram showing a state where the blood 10 is sufficiently diffused in the reaction region 21, and FIG. Is a schematic view of a state where blood is not sufficiently diffused in the reaction region.

  FIG. 10 is a diagram showing the relationship between the fluorescence profile and the time with respect to the degree of blood diffusion. In FIG. 10, a fluorescence profile 60 indicates a state where the blood is sufficiently diffused in the reaction region, and a fluorescence profile 61 indicates a state where the blood is not diffused in the reaction region. Both fluorescence profiles are values measured using the blood of the same person.

  As shown in FIG. 9B, when the blood 10 does not diffuse in the reaction region 21, the blood 46 and the reagent are not sufficiently mixed in the reaction region 21, so that the emitted fluorescence 46 becomes small.

  As a result, as shown in FIG. 10, even if the fluorescence profile of the blood of the same person, the amount of change 62 of the fluorescence profile 61 in a state where the blood is not sufficiently diffused in the reaction region 21 is sufficiently diffused. When the characteristic value of the blood component is calculated from the fluorescent profile 61 that is smaller than the amount of change 63 of the fluorescent profile 60 in the state of being diffused and is insufficiently diffused, the characteristic value of the wrong blood component is calculated. There was a problem that.

  The present invention has been made to solve the above-described problems, and can determine whether or not blood spotted on a test piece is sufficiently diffused in the reaction region of the test piece. The purpose is to provide.

  In order to solve the conventional problem, a blood component measuring method according to claim 1 of the present invention is a reaction in which a reagent that reacts with blood and generates an optically detectable element related to the blood component is applied. A test piece having a region, spotting detection means for electrically detecting the amount of blood spotted on the test piece, and irradiating the reaction region of the test piece with light to remove blood in the reaction region A light detection unit that emits light and detects a light emission amount of the blood, and a medical diagnostic device that includes an arithmetic processing unit that calculates a characteristic value of the blood component based on the light emission amount of the blood detected by the light detection unit. In the blood component measurement method for measuring the blood component, the light emission amount of the blood is measured at a first predetermined time after a predetermined time has elapsed after detecting that the blood has been spotted on the test piece, Further on the basis of the first predetermined time The light emission amount of the blood is measured at a second predetermined time after a predetermined time has elapsed, the amount of change in the light emission amount of the blood from the first predetermined time to the second predetermined time is calculated, and the calculated change It is determined whether or not the blood spotted on the test piece is diffused to an appropriate range in the reaction region of the test piece from the amount.

  The blood component measurement method according to claim 2 of the present invention is the blood component measurement method according to claim 1, wherein the second predetermined time is set to a time before the characteristic reaction of the blood component occurs. It is characterized by that.

  The blood component measurement method according to claim 3 of the present invention is the blood component measurement method according to claim 1, wherein it is determined that the blood is diffused to an appropriate range in the reaction region of the test piece. It is characterized in that the spotting detection means of the medical diagnostic device determines whether or not the blood spotting amount is sufficient and calculates the characteristic value of the blood component.

  According to the blood component measurement method of the present invention, while monitoring the amount of spotted blood, the fluorescence value immediately after the spotting of blood is compared with the fluorescence value when a predetermined time has elapsed after spotting, and the comparison From the results, it was determined whether or not the blood was sufficiently diffused in the reaction area of the test piece, so there was a problem in the reaction area of the test piece and blood was sufficiently diffused in the reaction area of the test piece. Even in the case where there is not, it is possible to prevent erroneous calculation of the measurement result by detecting that the blood is not diffused and terminating the measurement process abnormally.

(Embodiment 1)
Hereinafter, the blood component measurement method according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. The configuration of the medical diagnostic device according to the first embodiment is the same as that of a conventional medical diagnostic device, and thus description thereof is omitted.

  FIG. 1 is a flowchart of a blood component measurement method according to the first embodiment, and FIG. 2 is a fluorescence profile for blood diffusion in the medical diagnostic apparatus according to the first embodiment.

  In FIG. 2, a fluorescence profile 70 indicates the amount of fluorescence when blood is sufficiently diffused in the reaction region, and a fluorescence profile 71 indicates the amount of fluorescence when blood is not diffused in the reaction region. . Both fluorescence profiles show the amount of fluorescence when the blood of the same person is used. Da is a threshold value of the fluorescence change amount for determining whether or not the blood is sufficiently diffused in the reaction region, and D1 and D2 are spotted and T1 time (for example, 15 seconds) elapses. The amount of change in fluorescence after the process, D1 = F1-F0 and D2 = F2-F0.

  First, after the user attaches the test piece 20 to the medical diagnostic device 100, the medical diagnostic device 100 performs a blood spotting detection process until the user spots the blood 10 on the test piece 20 (steps S1 to S1). Step S2 is repeated).

  When the user deposits blood 10 on test piece 20, first, in order to obtain a fluorescence amount that serves as a reference value for determining whether blood 10 is sufficiently diffused in reaction region 21 of test piece 20. The fluorescence detection process is performed. The amount of fluorescence at the time of spotting obtained at this time is the F0 value in FIG. 2 (step S3).

  Next, the procedure waits until the spotted blood 10 is expected to be sufficiently diffused in the reaction region 21 of the test piece 20. For example, it waits for 15 seconds after spotting (step S4).

  When 15 seconds have elapsed since the blood 10 was spotted, blood spotting detection processing is performed (step S5), and it is determined whether the amount of spotting of the blood 10 is sufficient (step S6).

  If it is determined in step S6 that the amount of spotted blood 10 is insufficient, an error process is performed (step S13), and the measurement process ends abnormally.

  On the other hand, if it is determined in step S6 that the amount of spotted blood 10 is sufficient, the fluorescence to be compared when determining whether the blood 10 is sufficiently diffused in the reaction region 21 of the test piece 20 or not. In order to acquire the quantity, a fluorescence detection process is performed. The amount of fluorescence acquired at this time is the F1 value or the F2 value in FIG. 2 (step S7).

  Then, by comparing the fluorescence amount acquired in step S3 with the fluorescence amount acquired in step S7, it is determined whether or not the blood 10 is sufficiently diffused in the reaction region 21 (step S8).

Here, the determination process in step S8 will be described in detail with reference to FIGS.
As shown in FIG. 9A, when the blood 10 starts to diffuse in the reaction region 21 on the upper surface of the lens 207, red blood cells (red pigments) of the blood are converted into the lens as shown in the section from time T0 to time T1 in FIG. Since it diffuses to the upper surface of 207, the amount of fluorescence decreases. In the first embodiment, whether or not the blood 10 is sufficiently diffused into the reaction region 21 is determined every 10 seconds based on the difference in the amount of fluorescence change after a predetermined time has elapsed since the blood 10 was spotted. That is, as shown in FIG. 2, when the amount of fluorescence change D1 after T1 time has elapsed after spotting is larger than the threshold value Da, it is determined that blood is sufficiently diffused in the reaction region, and spotting is performed. If the fluorescence change amount D2 after the elapse of T1 is smaller than the threshold value Da, it is determined that the blood 10 is not sufficiently diffused in the reaction region 21.

  In step S8, when it is determined that the blood 10 is not sufficiently diffused in the reaction region 21, an error process is performed (step S13), and the measurement process ends abnormally.

  On the other hand, when it is determined in step S8 that the blood 10 is sufficiently diffused in the reaction region 21, the spot amount is processed every predetermined time until the characteristic reaction of the blood component starts. For example, the process of spotting amount is performed every 10 seconds for 240 seconds (steps S9 and S10). Then, it is determined whether the amount of blood spotted is sufficient (step S11).

  If it is determined in step S11 that the amount of spotted blood 10 is not sufficient, an error process is performed (step S13), and the measurement process ends abnormally.

  On the other hand, if it is determined in step S11 that the amount of spotted blood 10 is sufficient, fluorescence detection processing is performed to calculate the characteristic value of the blood component, and the fluorescence amount is acquired (step S12). Then, it is determined whether or not the characteristic value of the blood component can be calculated from the fluorescence (fluorescence amount) acquired every predetermined time (step S14). If the characteristic value of the blood component can be calculated, the measurement process is terminated normally. Otherwise, the process returns to step S9.

  As described above, according to the blood component measuring method according to the first embodiment, the fluorescence amount immediately after the blood 10 is spotted on the test piece 20 and the fluorescence amount after a predetermined time has elapsed after spotting. By comparing, it was determined whether the spotted blood 10 was sufficiently diffused in the reaction region 21 of the test piece 20 and mixed with the reagent, so there was a problem in the reaction region of the test piece. Even if blood is not sufficiently diffused in the reaction area of the test piece, it is detected that the blood is not diffused and the measurement process is terminated abnormally, thereby preventing erroneous measurement results from being calculated. be able to.

  The blood component measurement method according to the present invention is a method for detecting the amount of spotted blood in a medical diagnostic device using a test strip containing a reagent that generates a fluorescence or other visible signal when a characteristic reaction of the blood component occurs. Useful as.

It is a flowchart figure of the blood component measuring method by Embodiment 1 of this invention. It is a figure which shows the fluorescence profile with respect to the diffusion state of the blood in the medical diagnostic instrument of the said Embodiment 1. FIG. It is a figure which shows the structural example of a test piece. It is a figure which shows the structural example of the spotting detection part of the medical diagnostic apparatus in the blood non-spotting state. It is a figure which shows the structural example of the spotting detection part of the medical diagnostic apparatus in a blood spotting state. It is a figure which shows the profile of the voltage concerning the electrode of a spotting detection part. It is a figure which shows the system structural example in the conventional medical diagnostic equipment. It is a flowchart figure of the detection method of the conventional blood spotting amount. It is the schematic of the diffusion condition of the blood in the reaction area | region of a test piece. It is a figure which shows the fluorescence profile with respect to the diffusion condition of the blood in the conventional medical diagnostic instrument.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Blood 20 Specimen 21 Reaction area 22 Spotting hole 23 Conducting plate 24 Conducting plate 31 Electrode 32 Electrode 35 Voltage profile immediately after spotting 36 Voltage profile when blood spotting amount is sufficient 37 Blood spotting amount is unsatisfactory Voltage profile when sufficient 60 Fluorescence profile when blood diffusion is sufficient 61 Fluorescence profile when blood diffusion is insufficient 62 Fluorescence change amount when blood diffusion is insufficient 63 When blood diffusion is sufficient 70 Fluorescence profile when blood diffusion is sufficient 71 Fluorescence profile when blood diffusion is insufficient 100 Medical diagnostic equipment 101 A / D converter 102 Microcomputer 202 Driver 203 Light source 204 Irradiation light 205 Projection filter 206 Fluorescence 207 Lens 208 Light receiving filter 209 Photodiode 21 Electrical signals

Claims (3)

A test strip having a reaction area coated with a reagent that reacts with blood and produces an optically detectable element associated with the blood component;
Spotting detection means for electrically detecting the amount of blood spotted on the test piece, irradiating the reaction area of the test piece with light to emit light in the reaction area, and emitting the blood Blood component measurement using a light detection means for detecting the amount and a medical diagnostic device having a calculation processing means for calculating a characteristic value of the blood component based on the light emission amount of the blood detected by the light detection means In the blood component measurement method for performing
Measuring the amount of luminescence of the blood at a first predetermined time after a predetermined time has elapsed after detecting that the blood has been spotted on the test piece;
Measuring the amount of luminescence of the blood at a second predetermined time after a further predetermined time with respect to the first predetermined time;
Calculating the amount of change in the amount of luminescence of the blood from the first predetermined time to the second predetermined time;
It is determined whether the blood spotted on the test piece is diffused to an appropriate range in the reaction region of the test piece from the calculated amount of change,
The blood component measuring method characterized by the above-mentioned. The blood component measuring method according to claim 1,
The second predetermined time is set to a time before the characteristic reaction of the blood component occurs.
The blood component measuring method characterized by the above-mentioned. The blood component measuring method according to claim 1,
After determining that the blood is diffused to an appropriate range in the reaction region of the test piece, it is determined whether or not the amount of blood spotted is sufficient by the spotting detection means of the medical diagnostic instrument, Calculate characteristic values of blood components,
The blood component measuring method characterized by the above-mentioned.

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