JP7015521B2 - Whole blood albumin analyzer and whole blood albumin analysis method - Google Patents

Description

The present invention relates to a whole blood albumin analyzer and a whole blood albumin analysis method, and in particular, POCT (Point Of Care) capable of calculating an estimated serum albumin (hereinafter, also referred to as ALB) value from albumin measurement results using whole blood. Testing: A whole blood ALB analyzer and a whole blood ALB analysis method for ultra-trace blood for immediate clinical site testing).

Protein-Energy Malnutrition (PEM) in the elderly is considered to be a cause of prolonged recovery from illness, and nutritional management has become an important issue. Elderly PEMs are characterized by a deficiency of animal protein, and it has been reported that about 40% of inpatients and about 30% of home medical patients have hypo-ALBemia (3.5 g / dL or less). When these malnourished PEM patients are transported to an acute care institution, surgery can only be performed after nutritional recovery, resulting in prolonged hospitalization, increased complication rate, and worst. In the case of, it causes an increase in the number of bedridden care patients.

For this reason, each medical institution recognizes that patient nutrition monitoring based on appropriate patient nutrition evaluation and improvement from patient hyponutrition (PEM) are indispensable not only for improving patient prognosis but also for improving the efficiency of medical resources. It has been recognized that nutrition assessment by the nutrition support team (NST) is essential.

The nutritional evaluation of patients by the nutrition support team (NST) is largely composed of "physical assessment" and "clinical examination assessment". Objective nutritional evaluation is performed by "clinical test assessment", and ALB level, total protein level, RapidTurnoverProtein (RTP), etc. in blood collected from patients by biochemical test are measured, and these are used as static nutritional evaluation index. It is monitored as a dynamic nutrition index. In home medical care, it is important to continuously monitor these nutritional evaluation monitoring indicators in order to improve the vaccine effect and prevent stagnation.

General hospitals use large-scale automated biochemical analyzers when performing biochemical tests on patient blood. Venous blood is collected from patients by doctors and nurses, and the serum or serum collected by centrifugation is analyzed, and the analysis accuracy is extremely high. On the other hand, in terms of introduction and operation, (1) the equipment price is high. (2) A large amount of blood is required for centrifugation of serum. (50 kg to several mL) (3) Large device (several 100 kg) (4) Due to problems and restrictions such as indispensable reagent management and quality control, it is difficult to use the device in home medical care and home-visit medical care. be.

The biochemical analysis items that can be used in home medical care, fully automatic biochemical analyzers for POCT, etc. are limited to markers of myocardial infarction and self-blood glucose, and POCT devices for nutritional evaluation have not been developed. The reason for this is that small POCT devices with high portability, such as self-monitoring blood glucose measurement POCT devices, are measured by an electrochemical method using enzyme electrodes in order to handle trace amounts of whole blood. This is because it is difficult to develop an enzyme electrode that specifically responds to proteins and the like.

Therefore, a POCT device for analyzing a nutritional index corresponding to a trace amount of whole blood has not been put into practical use, and it is necessary to establish a measurement technique by a completely different method that has not been adopted in the POCT device so far. ..

The following Patent Document 1 discloses a method for rapidly obtaining a measurement result from a whole blood state in the measurement of a specific component in blood. This method is (1) a step of diluting a whole blood sample with a solution containing an oxidizing agent and a surfactant. (2) A step of measuring the target component of the diluted sample. (3) A step of quantifying the amount of hemoglobin (Hb) in the diluted sample. (4) The step of converting the measurement result in (2) into the measurement result when serum or plasma is measured by performing hematocrit (Ht) correction based on the quantitative value in (3) is included.

Japanese Unexamined Patent Publication No. 2013-36959

The above-mentioned conventional technique has the following problems. In the measurement with the conventional liquid reagent, although the measurement principle by the fully automatic biochemical analyzer used in medical institutions and the like has been established, the measurement target is serum and not the whole blood. The reason is that in the colorimetric analysis method, a large absorbance error and volume error occur due to blood cell components such as red blood cells contained in whole blood, and it is necessary to correct the influence of the blood cell component contained in whole blood. .. For this reason, conventionally, a serum centrifuge device is required for the measurement method, and there is a problem that a simple, inexpensive and accurate fully automatic biochemical analyzer for home medical care and POCT cannot be put into practical use.

An object of the present invention is to solve the above-mentioned problems of the prior art, to measure the whole blood ALB value using 1 to 2 μL of a trace amount of whole blood obtained from a fingertip in home medical care, and to measure the whole blood ALB value from the whole blood ALB value. It is an object of the present invention to provide a simple, inexpensive and accurate fully automatic biochemical analyzer capable of accurately calculating an estimated serum ALB value using a data correction formula.

In the present invention, in home medical care, the whole blood ALB value and the hemoglobin (hereinafter, also referred to as Hb) value are simultaneously measured using 1 to 2 μL of a trace amount of whole blood obtained from a fingertip, and the Hb concentration is referred to. It was decided to perform concentration error correction and volume correction based on the red blood cell components contained in the whole blood ALB value, and to calculate an accurate estimated serum ALB value from the whole blood ALB value using a data correction formula.

The whole blood ALB analyzer of the present invention uses a whole blood albumin absorbance measuring means for measuring whole blood albumin absorbance using a mixed solution of whole blood and a reagent for detecting hemoglobin, and a mixed solution of whole blood and a reagent for detecting hemoglobin. The hemoglobin absorbance measuring means for measuring the hemoglobin absorbance, the hemoglobin concentration converting means for converting the measured hemoglobin absorbance to the hemoglobin concentration, and the whole blood albumin absorbance measured by referring to the hemoglobin concentration to the serum albumin concentration. The main feature is that it is provided with a means for converting an albumin concentration to be converted and a means for displaying the serum albumin concentration.

Further, in the whole blood ALB analyzer described above, the albumin concentration converting means is also characterized in that conversion is performed using a calibration curve approximation formula including the hemoglobin concentration as a variable. Further, in the whole blood ALB analyzer described above, the calibration curve approximation formula is represented by a linear formula, and the slope and intercept of the linear formula are also characterized in that a variable representing the hemoglobin concentration is included. be. Further, in the whole blood ALB analyzer described above, the albumin concentration converting means is also characterized in that it is provided with a volume correction means for correcting the serum albumin concentration by obtaining the volume ratio of blood cells with reference to the hemoglobin concentration. ..

Further, the whole blood ALB analysis method of the present invention is a step of measuring whole blood albumin absorbance using a mixed solution of whole blood and a hemoglobin detection reagent, and hemoglobin absorbance using a mixed solution of whole blood and a hemoglobin detection reagent. A step of measuring, a step of converting the measured hemoglobin absorbance into a hemoglobin concentration, a step of converting the measured whole blood albumin absorbance into a serum albumin concentration with reference to the hemoglobin concentration, and a step of displaying the serum albumin concentration. The main feature is to include it.

Further, the above-mentioned whole blood ALB analysis method is also characterized in that the step of converting to the serum albumin concentration is performed by using a calibration curve approximation formula including the hemoglobin concentration as a variable. The whole blood ALB analysis method is also characterized in that the calibration curve approximation formula is represented by a linear formula, and the slope and intercept of the linear formula include a variable representing the hemoglobin concentration. be. The whole blood ALB analysis method is also characterized in that the albumin concentration converting means corrects the serum albumin concentration by obtaining the volume ratio of blood cells with reference to the hemoglobin concentration.

The whole blood ALB analyzer and the whole blood ALB analysis method of the present invention have the following effects. (1) It is possible to correct errors in hemolyzed serum samples, and it is possible to provide a highly accurate ALB measuring device in home medical care. (2) Since the blood centrifuge operation is not required, the biochemical analyzer can be miniaturized and the price can be reduced, and since it is highly portable, it can be easily used for home medical care, POCT, and the like. (3) Measurement with a small amount of blood using a lancet or the like becomes possible, and the burden on the subject is reduced.

FIG. 1 is a block diagram showing a hardware configuration of the ALB analyzer of the present invention. FIG. 2 is a block diagram showing a hardware configuration of the measuring device of the present invention. FIG. 3 is a flowchart showing the contents of the ALB analysis process in the ALB analyzer of the present invention. FIG. 4 is a flowchart showing the contents of the Hb (ALB) measurement process in the ALB analyzer of the present invention. FIG. 5 is a flowchart showing the contents of the blank measurement process in the ALB analyzer of the present invention. FIG. 6 is a flowchart showing the contents of the reagent reaction liquid absorbance measurement process in the ALB analyzer of the present invention. FIG. 7 is a flowchart showing the contents of the serum ALB value calculation process in the ALB analyzer of the present invention. FIG. 8 is a flowchart showing the contents of the calibration curve creation process of the present invention. FIG. 9 is an explanatory diagram illustrating a calibration curve for each Hb concentration. FIG. 10 is an explanatory diagram illustrating the relationship between the Hb concentration and the intercept. FIG. 11 is an explanatory diagram illustrating the relationship between the Hb concentration and the slope. FIG. 12 is a graph showing absorption spectra measured by dissolving Hb having a plurality of concentrations in an ALB measuring reagent.

Hereinafter, embodiments of the present invention will be described. First, the ALB measurement method used in the apparatus of the present invention will be described. Currently, the dye binding method is mainly used for the ALB measurement method, and there are two methods, the BCG method using bromocresol green and the BCP method using bromocresol purple. In the BCG method, ALB in a sample binds to bromocresol green (BCG) at around pH 4.0, and the ALB / bromocresol green complex produced is obtained by measuring the absorbance. ..

On the other hand, the BCP method measures the ALB concentration by colorimetrically measuring the bluish purple color of the ALB-bromocresol purple complex produced by ALB binding to bromocresol purple (BCP) in the presence of a surfactant. It is what you want.

The BCG method measures proteins other than ALB (globulin, C-reactive protein, etc.)
Although it has cross-reactivity with, the measurement can be completed only with the first reaction reagent, whereas the BCP method uses the first reaction reagent and the second reaction reagent in the measurement. Since the internal structure of the apparatus becomes complicated by increasing the reaction process by one step as compared with the BCG method, the BCG method is adopted as a basic principle in the present invention.

The BCG method is an analytical technique for serum after centrifugation and cannot be used for analysis of whole blood. Therefore, in the present invention, an algorithm for converting a whole blood analysis value into a serum ALB value in a POCT analyzer for ALB corresponding to the BCG method has been developed.

Next, the whole blood ALB measurement wavelength will be described. The basic principle of the BCG method is that blood ALB turns blue when bound to bromcresol green (BCG), and the pH error caused by the binding to ALB is measured at 630 to 660 nm.

However, since the conventional method is a principle for serum analysis, Hb having a concentration of 0 g / dl to 10 g / dl is dissolved in a BCG measurement reagent in a whole blood reaction system in order to determine the measurement wavelength in order to cope with whole blood. The absorptiometry vector analysis measured in the above was performed. FIG. 12 is a graph showing an absorbance vector measured by dissolving Hb having a plurality of concentrations.

Then, as a result of measuring the absorption spectrum, the following results were obtained. (1) Wavelength that is not affected by Hb and increases absorbance → 800 nm (2) Wavelength that is most affected by Hb but most sensitive → 600 to 650 nm (3) Wavelength that is slightly affected by Hb → 530 to 540 nm From the results of this study, 600 to 650 nm was set as the first selection wavelength, 540 nm was set as the second selection wavelength, and 800 nm was set as the third selection wavelength. The first selection wavelength of 600 to 650 nm has the highest sensitivity, but since the influence of Hb is the largest, high-precision whole blood ALB measurement cannot be performed as it is. Therefore, in the present invention, by correcting the influence of the Hb concentration, it is possible to perform highly accurate whole blood ALB measurement using a highly sensitive wavelength.

Next, an algorithm for estimating serum ALB value from whole blood ALB value will be described. (1) Analysis of the effect of whole blood on the ALB calibration curve A calibration curve for converting the absorbance to the ALB value is required for the quantification of the ALB value, but the effect of the Hb concentration on the whole blood measurement is based on the results of the absorption spectrum analysis. It is clear that you will receive. Therefore, Hb was added to the serum of each ALB concentration, and an experiment was conducted to see if the effect of whole blood could be corrected.

As a result, the ALB calibration curve showed linearity regardless of the Hb concentration. Therefore, it can be approximated by a linear approximation formula. It was also found that as the Hb concentration increased, the difference in absorbance between the ALB concentrations Og / dl and 5.0 g / dl decreased.

Next, when the corrected calibration curve when the influence of the initial value absorbance is removed is examined, the slope of the ALB calibration curve varies depending on the Hb concentration contained therein. From this, it is clear that the slope of the calibration curve decreases in proportion to the Hb concentration, and it is clear that the correction value can be calculated from the intercept and slope in the conversion from whole blood to the serum ALB value. It became. Hereinafter, examples will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a hardware configuration of the ALB analyzer of the present invention. The PC (personal computer) 10 may be, for example, a well-known personal computer provided with a general-purpose digital input / output interface circuit or the like. The display device 11 is a well-known output device such as a liquid crystal display device. The keyboard 12 and the mouse 13 (which may be a touch panel or a trackball) are well-known input devices used by the operator for input. The ALB analyzer of the present invention is realized by creating a program for executing the process described later and installing it on the PC 10.

Although the details will be described later, the measuring device 20 is connected to the PC 10 via a general-purpose digital input / output interface, measures the absorbance of the sample based on the control from the PC 10, and outputs the sample to the PC 10. In the present invention, for example, the blood (whole blood) 21 collected by the subject himself / herself with a lancet or the like is placed in two cupets 24 containing a predetermined amount of each of the ALB reagent 22 and the known Hb reagent 23, which will be described later. Add only a fixed amount and set it in the measuring device 20.

FIG. 2 is a block diagram showing a hardware configuration of the measuring device 20 of the present invention. The control circuit 30 of the measuring device 20 is a control circuit that measures the absorbance of the sample based on the control from the PC 10. The control circuit 30 includes a general-purpose digital input / output interface circuit, a plurality of digital input / output terminals, a plurality of analog input terminals, and the like, and outputs the voltage of the analog input terminal to the PC 10 by analog digital conversion based on the control from the PC 10. Has a function.

As the control circuit 30, any well-known one-chip computer having necessary functions can be adopted. The power supply 31 inputs, for example, a power supply supplied from a general-purpose digital input / output interface or a commercial power supply, and supplies the necessary power supply inside the measuring device 20.

Inside the measuring device 20, two sets of absorbance measuring devices, one for ALB measurement and the other for Hb measurement, are provided. The structure of each device is the same, but the wavelengths to be measured are different. In the absorbance measuring device for ALB measurement, light having a wavelength of 630 nm is generated by a light emitting diode 33 and an optical filter 35. Further, in the absorbance measuring device for Hb measurement, light having a wavelength of 530 nm is generated by the light emitting diode 34 and the optical filter 36.

The two drive circuits 32 are circuits that drive a light emitting diode 33 or 34 to emit light based on an instruction signal from the control circuit 30. The light emitted from the light emitting diode 33 or 34 passes through the optical filter 35 or 36, the transparent container, and the cuppet 24 and reaches the photodiode 40. The sensor circuit 41 amplifies a voltage signal proportional to the amount of light received generated in the photodiode 40 by using the power supply supplied from the sensor power supply 42, and outputs the voltage signal to the analog input terminal of the control circuit 30.

Here, an outline of the ALB measurement procedure using the ALB analyzer will be described. First, the power of the ALB analyzer of the present invention is turned on, the system is initialized, and the absorbance at the time of blanking is measured. Next, the subject collects 3 μL of blood by self-collection, and divides it into 2 μL for Hb measurement and 1 μL for ALB measurement into two cuppets 24 containing reagents for Hb measurement and ALB measurement, respectively. Then, after reacting, they are set in the measuring device and the absorbance is measured. Finally, a data conversion process for Hb correction is performed to calculate and display the estimated serum ALB value.

FIG. 3 is a flowchart showing the contents of the ALB analysis process in the ALB analyzer of the present invention. In S10, it is determined whether or not the operator who is the subject has given an Hb measurement instruction, and if the determination result is negative, the process proceeds to S12, but if the determination result is affirmative, the process proceeds to S11. In S11, the Hb measurement process described later is performed.

In S12, it is determined whether or not there is a whole blood ALB measurement instruction from the operator, and if the determination result is negative, the process proceeds to S13, but if the determination result is affirmative, the process proceeds to S14. In S13, the whole blood ALB measurement process described later is performed. In S14, it is determined whether or not the binary measurement is completed, and if the determination result is negative, the process proceeds to S10, but if the determination result is affirmative, the process proceeds to S15. In S15, the serum ALB value calculation process described later is performed.

FIG. 4 is a flowchart showing the contents of the Hb (whole blood ALB) measurement process S11 (S13) in the ALB analyzer of the present invention. The contents of the Hb measurement process and the whole blood ALB measurement process are the same except for the difference between the two sets of absorbance measuring devices for ALB measurement and Hb measurement.

In S20, the system is initialized, and in S21, a blank cuppet 24 containing only the reagent 22 or 23 is set in the measuring device 20 and a blank measurement process for measuring the absorbance is performed. In S22, the absorbance measurement process using the reagent-reacted blood described later is performed.

FIG. 5 is a flowchart showing the contents of the blank measurement process S21 in the ALB analyzer of the present invention. In S30, a display is displayed instructing the measuring device 20 to set a blank cuppet 24 containing only the reagent 22 or 23, and after the setting is confirmed, the control circuit 30 of the measuring device 20 is displayed. The measurement of the output voltage of the two photodiodes 40 is instructed, and the two measured voltage digital values are read.

In S31, it is checked whether or not the read voltage value is normal by checking whether or not it is within a predetermined range. If it is an abnormal value, an abnormal state is displayed and the process ends. In S32, the measured voltage value at the time of blanking, that is, at the time of 100% transmittance (absorbance 0) is recorded for each of the two sets of absorbance measuring devices. This value is used to calculate the absorbance.

FIG. 6 is a flowchart showing the contents of the reagent reaction liquid absorbance measurement process S22 in the ALB analyzer of the present invention. In S40, the reagent reaction time is counted. When the reaction is completed in about 5 minutes, for example, the reagent counts for 5 minutes and waits. In S41, a display is displayed instructing the measuring device 20 to set the cupet 24 in which the reagent is added to the whole blood, and after the setting is confirmed, the output voltage of the photodiode 40 is transmitted to the control circuit 30 of the measuring device 20. Instruct the measurement and read the measured voltage digital value.

In S42, whether or not the read voltage value is normal is checked by checking whether or not the read voltage value is within a predetermined range. If it is an abnormal value, an abnormal state is displayed and the process ends. In S43, the reagent reaction blood measurement voltage value is recorded together with the measurement frequency information, and in S44, the absorbance is calculated. The absorbance is calculated by the following formula.

Reagent reaction Blood measurement voltage value is I. The measured voltage at the time of blank is I0. Transmittance (% T) = (I / I0) × 100, absorbance (ABS) = −Log (% T / 100) = 2-Log (% T) However, Log is a common logarithm.

In S45, it is determined whether or not the measurement has been completed a predetermined number of times, for example, five times. If the determination result is negative, the process proceeds to S46, but if the determination result is positive, the process proceeds to S47. In S46, the process proceeds to S41 after waiting for a predetermined time, for example, one minute.

In S47, it is determined whether or not there is a change in the absorbance, and if the determination result is negative, the process proceeds to S48, but if the determination result is positive, the process proceeds to S49. In S48, the process proceeds to error processing, an abnormal state is displayed, and processing is terminated. The reason for determining whether or not there is a change in the absorbance in S47 is to confirm that the reaction is completed and stabilized.

The rate of change in absorbance is calculated by the rate of change = (nth absorbance)-(n-1st absorbance)) ÷ (nth absorbance), and when the rate of change is + 5% or more, it is considered to increase (with fluctuation). As a result of the experiment, the reaction was almost completed at the stage after 5 minutes, and almost no change was observed even when the measurement was performed up to the 5th time. Therefore, in this embodiment, the case where the reaction is stable by the third time and there is no change after that is determined to be the end of the reaction (normal end).

In S49, the absorbance to be output is determined. As the absorbance, the fifth value may be adopted, or the average value of a plurality of absorbances without fluctuation may be adopted. The rate of change may be calculated for each measurement, and the ALB concentration may be calculated from the calibration curve using the absorbance value without fluctuation (for example, the second absorbance value) and displayed as a breaking news value.

FIG. 7 is a flowchart showing the contents of the serum ALB value calculation process S15 in the ALB analyzer of the present invention. In S50, the Hb concentration value is calculated and displayed. The quadratic approximation formula of the calibration curve that converts the Hb absorbance for each reagent into the Hb concentration value is determined by a known method by a measurement experiment using this analyzer and sample blood in which the Hb concentration value and the ALB concentration value are known in advance. , Is remembered. Therefore, the Hb concentration value is calculated and displayed by substituting the measured Hb absorbance into the calibration curve approximation formula that converts the Hb absorbance into the Hb concentration value.

In S51, the whole blood ALB concentration is calculated and displayed from the absorbance using a calibration curve in the case where Hb is not contained in advance. In a clinical laboratory device, the value before correction or the like may also be clinically useful. Therefore, if a calibration curve that does not include Hb is used, what kind of numerical value will be obtained is simply calculated and displayed as a reference value.

In S52, an Hb concentration influence correction calibration curve (formula) is created. The calibration curve formula is created by substituting the Hb concentration obtained in S50 into the variable H in the calibration curve formula which is a linear approximation formula having the Hb concentration as a variable prepared in advance by the method described later. As a result of the experiment by the present inventor, for example, the following calibration curve formula was obtained in the prototype device. y = (0.00004H ^ 2-0.0017H + 0.0626) x + (-0.0006H ^ 2 + 0.0502H + 0.0075). However, "H" is the Hb concentration and "^ 2" is the square.

In S53, the estimated serum ALB value (x) is calculated from the measured absorbance (y) by using the approximate formula of the Hb concentration influence correction calibration curve described above. The ALB concentration x can be determined by x = (y−b) / a.

In S54, the Ht approximate value (blood cell volume ratio) is calculated from the Hb concentration value. The blood cell portion of blood does not contain ALB, and the ALB concentration calculated by the calibration curve is contained in serum. In addition, the volume ratio of serum varies from person to person. Therefore, it is necessary to correct the volume. Normally, it is best to measure the Ht value to determine the serum ratio, but in POCT, a centrifuge or blood cell counter cannot be used. Therefore, the predicted value of the Ht value is calculated from the Hb concentration.

First, the absorbance is measured in the ALB analyzer of the present invention using various sample blood having a predetermined Hb concentration value and a known blood cell volume ratio. Then, the vertical axis represents the Ht blood cell volume ratio and the horizontal axis represents the Hb concentration (graphed), and a linear approximation formula is obtained by a known method such as the least squares method. This linear approximation formula is a straight line rising to the right. An example of this linear approximation formula is shown below. As a result of the experiment by the present inventor, for example, the following mathematical formula was obtained in the prototype device. From this formula, the Ht value (y) can be estimated from the Hb value (x).

y = 2.0817x + 11.446

In S55, the volume data is corrected by the approximate Ht value. From the Ht value, the amount of serum actually contained in the whole blood can be known. For example, if Ht is 40%, 60% of the actually measured whole blood sample is the serum level. Therefore, the blood cell volume correction value = (ALB concentration from whole blood × {100 / (100-Ht)}) is used to calculate the blood cell volume correction value.

In S56, the measured sample amount is corrected. In the original BCG method (serum analysis), the reaction ratio between the reagent and blood in the measurement of the ALB value with serum is that 20 μL of serum is mixed with 5 mL of the color-developing reagent (mixing ratio 500: 2). However, in the embodiment of the present invention, the reaction ratio between the reagent and blood in the measurement of the ALB value in whole blood is set to mix 1 μL of whole blood with 500 μL of the color-developing reagent (mixing ratio 500: 1). For high-concentration blood samples that exceed the upper limit of measurement, 0.5 μL of whole blood is mixed with 500 μL of the color-developing reagent (mixing ratio 1000: 1). This correction can be omitted when the mixed blood volume is the same due to the characteristics of the sample.

This is because it became clear from the experimental results that in the whole blood measurement, it is desirable to set the mixing ratio to 500: 1 in order to completely hemolyze and obtain the optimum absorbance for the measurement. Therefore, since the measurement is performed with half the original blood volume, it is necessary to finally match the measured amount with the original method, and the measurement result is corrected to twice the value as the measurement sample amount correction. Further, in the case of a high-concentration blood sample exceeding the upper limit of measurement, the mixing ratio of the mixed blood volume similarly reduced is corrected. In S57, the corrected estimated serum ALB value is displayed, and the process is terminated.

FIG. 8 is a flowchart showing the contents of the calibration curve creation process of the present invention. If the patient's Hb concentration is measured simultaneously with another measurement system and the information is used to calculate how much the increase in absorbance was, then the increase due to Hb is subtracted from the measured absorbance to achieve ALB with serum alone. Absorbance can be calculated for the time being. However, as a result of the experiment, it was found that the ALB value cannot be calculated with high accuracy by simply subtracting the absorbance due to Hb.

That is, the calibration curve for ALB measurement, which converts the absorbance of whole blood into the serum ALB concentration, can be approximated by a linear approximation formula because the linearity is good as a result of the experiment. It was found that the inclination of was reduced. Therefore, if the slope and intercept change due to Hb concentration can be mathematically expressed by a calibration curve linear approximation formula, a calibration curve for ALB measurement can be created in real time according to the patient Hb value, and the estimated serum ALB value can be calculated with high accuracy. It is possible to display.

First, the calibration curve is y = ax + b. Here, y is the absorbance obtained by measuring ALB in whole blood, and x is the estimated serum ALB concentration value to be obtained. Regarding the slope a, the slope a of the calibration curve decreases as the Hb concentration increases. For the intercept b, the intercept b becomes larger as the Hb concentration increases. The ALB concentration x can be determined by x = (y−b) / a.

In S60, the absorbance is measured by the ALB analyzer of the present invention using various sample bloods having a predetermined Hb concentration value and a known ALB concentration value. In S61, the measurement results are summarized for each Hb concentration value, the vertical axis is the absorbance and the horizontal axis is the ALB concentration (graphed), and a known method such as the least squares method is used to linearly approximate the calibration curve for each Hb concentration value. Find the formula.

FIG. 9 is an explanatory diagram illustrating a calibration curve for each Hb concentration. As shown in FIG. 9, the calibration curve linear approximation formula for each Hb concentration value is a straight line rising to the right as the intercept becomes larger as the Hb concentration increases. The linear approximation formula for each Hb concentration is a calibration curve when the hemoglobin concentration is a known predetermined value.

In S62, an approximate expression for converting the Hb concentration into the intercept b is calculated. FIG. 10 is an explanatory diagram illustrating the relationship between the Hb concentration and the intercept. In order to formulate the y-intercept of the calibration curve linear approximation formula for each Hb concentration, that is, the correlation between the absorbance and the moglobin concentration when the ALB concentration value is 0, the vertical axis is the intercept and the horizontal axis is the Hb concentration (graph). ), And obtain a quadratic approximation formula by a known method. By using this quadratic approximation formula, the intercept b can be obtained from the measured Hb concentration. As a result of the experiment by the present inventor, for example, the following approximate expression of the intercept b was obtained in the prototype device. b = −0.0006H ^ 2 + 0.0502H + 0.0075, where “H” is the Hb concentration and “^ 2” is the square.

In S63, an approximate expression for converting the Hb concentration into the slope a is calculated. FIG. 11 is an explanatory diagram illustrating the relationship between the Hb concentration and the slope. In order to formulate the correlation between the slope of the calibration curve linear approximation formula for each Hb concentration (coefficient of the first-order term) and the Hb concentration, the vertical axis is tilted and the horizontal axis is the Hb concentration (graphed). The quadratic approximation formula is obtained by the method of. By using this quadratic approximation formula, the slope a can be obtained from the measured Hb concentration. As a result of the experiment by the present inventor, for example, the following approximate expression of the inclination a was obtained in the prototype device. a = 0.00004H ^ 2-0.0017H + 0.0626, where "H" is the Hb concentration and "^ 2" is the square.

In S64, a calibration curve formula is created. As a result of the experiment by the present inventor, for example, the following calibration curve formula was obtained in the prototype device. y = (0.00004H ^ 2-0.0017H + 0.0626) x + (-0.0006H ^ 2 + 0.0502H + 0.0075). However, "H" is the Hb concentration and "^ 2" is the square.

The present inventor conducted an evaluation with the cooperation of a large number of healthy adults in order to verify the correlation between the measurement results obtained by the apparatus of the present invention and the conventional automatic biochemical analyzer. As a result, the measured serum ALB value and the serum ALB estimated value from the whole blood ALB value were highly correlated and consistent.

Next, the ALB measurement reagent 22 used for this measurement will be described. First, (a) disodium succinate 27.014 g was dissolved in distilled water to make 1000 mL of the disodium succinate solution, and (2) 10.07 g of anhydrous succinic acid was dissolved in distilled water to make 1000 mL. An acid solution is prepared, and 700 mL of the solution of (2) is mixed with 300 mL of the solution of (1) to prepare a succinic acid buffer.

Next, 10.0 g of Briji35 as a surfactant is weighed, 70 mL of distilled water is added, and the mixture is heated and dissolved at 60 ° C., and after cooling, distilled water is added to make 100 mL. (4) An aqueous solution of Briji35 is prepared.

Next, as a BCG stock solution, 0.7 g of BCG was dissolved in 10 mL of 0.1 mol / LNaOH, and distilled water was added to make 100 mL. After storage for 24 hours, the precipitate is filtered through a filter paper to prepare a (5) BCG storage solution stored in a brown bottle.

Finally, as the BCG color-developing reagent, the above-mentioned (3) 0.1 mol / LpH 4.2 succinic acid buffer 500 mL and (4) Briji35 aqueous solution 12 mL (surfactant concentration may be 0.06 to 0.12%). ), (5) Mix 15 mL of the BCG preservative solution and make 1000 mL with distilled water to prepare the ALB concentration measuring reagent 22.

As a result of conducting an experiment on the ALB reagent, regarding the effect of the Briji35 concentration on the hemolysis degree, the succinic acid buffer + Briji35 concentration (5%) had the lowest hemolysis degree, and the hemolysis degree was 10% or more or 0.1% or less. Turned out to be high. Therefore, the known reagent composition may be used as it is for the ALB measurement reagent, but the whole blood sample can be completely hemolyzed even if the concentration of the contained surfactant is 0.1% or less.

Although the examples have been described above, the following modifications can be considered in the present invention. Although an example of using a PC has been disclosed in the examples, the device for processing may be a notebook PC, a tablet PC, a smartphone, or the like, and further, a processing device, a display device, an input device, or the like is provided in the measuring device. The processing device and the measuring device may be integrated.

The present invention is applicable to a fully automatic biochemical analyzer that measures serum ALB levels in home medical care and the like.

10 ... PC 11 ... Display device 12 ... Keyboard 13 ... Mouse 20 ... Measuring device 21 ... Blood 22 ... ALB reagent 23 ... Hb reagent 24 ... Cupet

Claims (4)

A whole blood albumin absorbance measuring means for measuring the whole blood albumin absorbance, which is the absorptivity caused by whole blood albumin, using a mixed solution of whole blood and a reagent for detecting albumin.
A hemoglobin absorbance measuring means for measuring hemoglobin absorbance using a mixed solution of whole blood and a reagent for detecting hemoglobin, and
A hemoglobin concentration conversion means for converting the measured hemoglobin absorbance into a hemoglobin concentration,
Using a calibration curve approximation formula containing the hemoglobinometry as a variable , the measured whole blood albumin absorbance is converted into a serum albumin concentration, and the volume ratio of blood cells is obtained with reference to the hemoglobinometry to obtain the serum albumin concentration. Albumin concentration conversion means to further correct,
A whole blood albumin analyzer provided with a display means for displaying the corrected serum albumin concentration. The whole blood albumin analyzer according to claim 1 , wherein the calibration curve approximation formula is represented by a linear formula, and the slope and intercept of the linear formula include a variable representing the hemoglobin concentration. .. A step of measuring the absorbance of whole blood albumin, which is the absorbance of whole blood caused by albumin, using a mixed solution of whole blood and a reagent for detecting albumin.
Steps to measure hemoglobin absorbance using a mixture of whole blood and hemoglobin detection reagents,
A step of converting the measured hemoglobin absorbance into a hemoglobin concentration,
Using a calibration curve approximation formula containing the hemoglobinometry as a variable , the measured whole blood albumin absorbance is converted into a serum albumin concentration, and the volume ratio of blood cells is obtained with reference to the hemoglobinometry to obtain the serum albumin concentration. Further correction steps,
A method for whole blood albumin analysis comprising the step of displaying the corrected serum albumin concentration. The whole blood albumin analysis method according to claim 3 , wherein the calibration curve approximation formula is represented by a linear formula, and the slope and intercept of the linear formula include a variable representing the hemoglobin concentration. ..

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