JP2008261733A - Blood analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blood analyzer and blood analysis method that centrifuge the blood, measure the absorbance of the separated plasma, and can detect the boundary position between the plasma and corpuscle under centrifugation. <P>SOLUTION: This blood analyzer has an absorbance measurement section capable of measuring the absorbance in a chamber into which a blood analyte to be centrifuged is injected. The threshold calculated from the previously measured absorbance of the plasma having no contaminant and absorbance of the plasma having contaminant is compared with the absorbance of the plasma obtained by centrifugation. Thus, plasma into which contaminant adversely affecting an analysis result is mixed is determined. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a blood analysis technique for performing analysis by separating blood by centrifugation and reacting its components with reagents. In particular, it relates to a technique for measuring separated plasma.

  In recent years, metabolic syndrome due to lifestyle-related diseases such as diabetes, hyperlipidemia, hypertension and obesity has become a problem due to obesity (particularly visceral fat type obesity). Since these are mainly caused by arteriosclerosis, it is necessary to regularly check blood sugar, neutral fat and cholesterol by blood test.

  Therefore, a POCT (Point-of-care Testing) blood test apparatus that is easy to handle even in a small-scale medical facility such as a clinic and capable of accurate measurement is desired. When measuring blood sugar, neutral fat, cholesterol, etc., a test using plasma is performed. However, since centrifugation is required to extract plasma from blood, the POCT blood test apparatus is provided with a centrifuge. (For example, refer to Patent Document 1).

  FIG. 9 illustrates a centrifuge used in a conventional POCT blood test apparatus. The centrifuge 94 includes a removable blood analyzer 90 into which a blood sample is injected, a centrifuge 91 that centrifuges the blood analyzer, a rotary stage 92 that changes the angle of the blood analyzer, and a rotary stage. A transfer machine 93 that transfers the blood analyzer between the centrifuges is provided.

Blood is injected into a blood analyzer 90 (not shown) arranged on the rotary stage 92, the blood analyzer 90 is moved to the centrifuge 91 by the transfer device 93, and the rotation center 95 is moved by the centrifuge 91. By rotating the rotor at a high speed, the blood is separated into plasma and blood cells, and the blood analyzer 90 is moved to the rotary stage by the transfer machine 93, and the blood is analyzed on the rotary stage 92.
JP 2005-241617 A

  However, in the conventional configuration, there is a case where correct measurement cannot be performed depending on blood used for blood analysis. That is, blood collected after meals or blood collected from hyperlipidemic patients has increased chylomicron and VDL in the blood, so that chyle plasma (plasma turns milky white) and hemolyzed plasma (red blood cells This results in a problem that it is impossible to obtain an accurate measurement value because a red blood plasma that is destroyed and a component such as hemoglobin flows out is generated.

  In the conventional configuration, since the centrifugation time is fixed, there is a problem that sufficient plasma cannot be obtained depending on blood for blood analysis.

  An object of the present invention is to solve the conventional problems described above, and to provide a blood analyzer that can measure only blood that can be measured correctly and that can accurately centrifuge plasma required for measurement.

  In order to solve the above-described conventional problems, the blood analyzer of the present invention includes a chamber for injecting blood for testing, a centrifuge controller for rotating the chamber to apply a centrifugal force, and a centrifuge process. An absorbance measuring unit for measuring the absorbance of blood to be examined later in the chamber, and a sample discriminating unit for discriminating whether the blood to be examined is normal or abnormal according to the absorbance of plasma measured by the absorbance measuring unit And an analysis procedure control unit that stops the analysis process when it is determined that the blood to be tested is abnormal.

  Furthermore, the blood analyzer of the present invention includes a chamber into which a blood sample can be injected, a centrifuge controller for rotating the chamber to apply a centrifugal force, and a blood to be examined in the chamber after the centrifuge process. An absorbance measurement unit for measuring absorbance; a boundary detection unit that determines a boundary position between plasma and blood cells during centrifugation based on a measurement result by the absorbance measurement unit; and a boundary position signal, based on the boundary signal And a centrifugal force control unit that changes the centrifugal force of the centrifugal separation control unit.

  According to the blood analyzer and the blood analysis method of the present invention, plasma (chyle plasma or hemolyzed plasma) mixed with impurities not suitable for analysis is measured by measuring the absorbance of plasma obtained after centrifuging blood. Therefore, the measurement of blood that cannot be analyzed can be eliminated, and only an accurate measurement value can be given to the measurer. In addition, since the boundary position between plasma and blood cells during centrifugation is detected, the optimum centrifugal force and centrifugation time can be obtained for the blood to be measured, so measurement with higher accuracy than conventional POCT hematology analyzers is possible. It can be performed.

  Embodiments of a blood analyzer and a blood analysis method of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a configuration diagram of a blood analyzer according to Embodiment 1 of the present invention. As shown in FIG. 1, blood to be examined is put in the chamber 11 and set in the rotor 10, and then the rotor 10 is rotated by the motor 13 to apply centrifugal force to the chamber 11. The light emitted from the light emitting unit 15 provided in the lower portion of the rotor 10 passes through the blood to be examined in the chamber 11 being centrifuged and reaches the light receiving unit 16 provided in the upper portion of the rotor 10. The absorbance of the transmitted light obtained by the light receiving unit 16 is measured by the calculation unit 17, and the output is sent to the sample determination unit 18. The specimen discriminating unit 18 discriminates the normality / abnormality of the blood to be inspected based on the transmitted absorbance, and sends the result to the analysis procedure control unit 19. If it is determined that there is an abnormality, the analysis procedure control unit 19 ends the blood analysis.

  2 and 3 are flowcharts showing the procedure of the specimen discrimination process according to the first embodiment of the present invention, and FIG. 4 is a diagram showing changes in the blood specimen in the chamber at the time of centrifugation. Hereinafter, detailed description will be given with reference to these drawings.

  When the blood analysis process is started, first, a blood sample is injected into the chamber 11 provided in the rotatable rotor 10 (S20). After completion of the injection, a centrifugation process is executed (S21). In the centrifugal separation process, a signal for rotating the motor 13 at a predetermined rotational speed is transmitted from the centrifugal controller 12, whereby the motor 13 rotates and the rotor 10 connected to the motor 13 rotates. When a certain period of time elapses while the rotor 10 is rotating, the blood sample in the chamber 11 provided in the rotor 10 is centrifuged and separated into plasma and blood cells.

  The degree of separation of plasma and blood cells with respect to the time required for centrifugation will be described with reference to FIG. As shown in FIG. 4A, immediately after the blood sample is injected into the chamber 11, plasma and blood cells are mixed in the chamber 40 shown in FIG. As the time required for centrifugation elapses, plasma and blood cells are gradually separated as shown in FIGS. 4 (b), 4 (c), and 4 (d). Generally, hematocrit, which is a value indicating the volume ratio of red blood cells present in blood, is 40-50% for men and 35-45% for women, so the ratio of plasma to blood cells is 5: 5 to If it becomes about 6: 4, it may be considered that it has been completely centrifuged.

  Subsequently, a plasma absorbance measurement process is executed (S22). The absorbance measurement unit 14 is used for measuring the absorbance of plasma. The absorbance measurement unit 14 includes a light emitting unit 15, a light receiving unit 16, and a calculation unit 17 provided for the chamber 11. First, light emitted from the light emitting unit 15 passes through the plasma portion of the chamber 11 and is received by the light receiving unit 16. Here, the installation positions of the light emitting unit 15 and the light receiving unit 16 with respect to the chamber 11 are arranged near the rotation center of the rotor 10 as shown in FIG. 1 in consideration of the aforementioned hematocrit. In the light receiving unit 16, photoelectric conversion is performed, and the amount of received light is output as a voltage. The output voltage is converted into digital data by an A / D converter in the calculation unit 17 to calculate the absorbance of plasma.

  Thereafter, the specimen discrimination processing is executed by the specimen discrimination section 18 (S23). The processing procedure of the sample determination unit 18 will be described with reference to FIG. The specimen discrimination is performed by comparing the aforementioned plasma absorbance with a threshold value (S30). The threshold value is determined by measuring the absorbance of normal and abnormal plasma in advance using the optical measurement system (light emitting part and light receiving part) of the blood analyzer in the manufacturing process of the blood analyzer. From these values, values that can determine the presence or absence of contaminants in the plasma are determined.

  The threshold value is stored in the specimen discriminating unit 18 and is compared with the absorbance calculated in the plasma absorbance measurement process to discriminate the presence / absence of contaminants in the plasma. As a result, the specimen characteristics of whether the blood sample is a normal blood sample having no contaminants in the plasma or an abnormal blood sample having contaminants in the plasma are found. Furthermore, in order to specify whether the sample is chyle plasma or hemolyzed plasma among samples that cannot be analyzed as desired, a plurality of threshold values may be provided for determination. This makes it clear why the desired analysis is not possible.

  Subsequently, when the desired analysis is possible based on the specimen characteristics obtained by the specimen discrimination process (S23), the reaction and analysis are executed (S25), and the blood analysis process is terminated. If the desired analysis is impossible, the analysis procedure control unit 19 does not perform the subsequent processing and ends the blood analysis processing.

  Further, in the first embodiment, when the plasma obtained by centrifugation can be identified as chyle plasma, the blood analysis process is not stopped as described above, but the absorbance of the chyle plasma is stored. In addition, by calculating the final analysis result and canceling the absorbance increased by chyle, the target analysis result can be obtained even in the case of chyle plasma.

  In addition, by making the chamber 11 provided in the rotor 10 of the first embodiment detachable, a different chamber 11 can be used for each analysis, and a process such as washing the chamber in the rotor 10 can be performed. Since it becomes unnecessary and the usability of the apparatus can be improved, the chamber 11 may be detachable and set to the rotor 10.

(Embodiment 2)
FIG. 5 is a block diagram of a blood analyzer according to the second embodiment of the present invention. As shown in FIG. 5, blood to be examined is put in the chamber 51 and set in the rotor 50, and then the rotor 50 is rotated by the motor 53 to apply a centrifugal force to the chamber 11. The light emitted from the light emitting unit 55 having a plurality of light sources provided in the lower part of the rotor 10 passes through the blood to be examined in the chamber 11 being centrifuged, and the light receiving parts provided in the upper part of the rotor 10. The light receiving unit 16 having The absorbance of the transmitted light obtained by the light receiving unit 16 is measured by the calculation unit 17, and the output is sent to the boundary detection unit 58. The boundary detection unit 58 measures the boundary position between plasma and blood cells and the absorbance of plasma based on a plurality of transmitted light transmitted, and sends the result to the centrifugal force control unit 59. The centrifugal force control unit 59 calculates the number of rotations of the motor 53 according to the result of the boundary detection unit 58, sends the result to the centrifugal separation control unit 53, and performs optimum centrifugation according to the blood to be examined.

  FIG. 6 is a flowchart of blood analysis processing in the second embodiment of the present invention, FIG. 7 is a schematic diagram showing changes in blood samples in the chamber during centrifugation in the second embodiment of the present invention, and FIG. FIG. 10 is a schematic diagram of a criterion for centrifugal force control in the second embodiment of the present invention.

  Hereinafter, the procedure of blood analysis processing will be described with reference to FIGS. When the blood analysis process is started, first, a blood sample is injected into a chamber 51 provided in the rotatable rotor 50 (S60). Next, the centrifugal separation process is started (S61), but the content of the centrifugal separation process is the same as that of the first embodiment, and thus the description thereof is omitted. Next, the absorbance is measured at a plurality of locations in the chamber 51 (S62), the boundary position between plasma and blood cells is detected (S63), and the centrifugal force is controlled (S64).

  These procedures will be described in detail with reference to FIG. FIG. 7 is a schematic diagram showing changes in the ratio of plasma and blood cells in the chamber during the centrifugation process, that is, changes in the boundary position between plasma and blood cells. Since the chamber 51 of FIG. 5 and the chamber 70 of FIG. 7 are the same, the English letters A to D and the numerals 1 to 4 of the light emitting unit 55 and the light receiving unit 56 of FIG. 5 and FIG.

  7 (a) to (d) show temporal changes in the same chamber, FIG. 7 (a) shows the fastest state in time, then (b), (c), and finally. It becomes figure (d). In addition, as shown in FIG. 7, a plurality of light emitting sources (A to D) of the light emitting unit 55 and a plurality of light receiving elements (1 to 4) of the light receiving unit 56 are provided at symmetrical positions with the chamber 70 interposed therebetween. In the figure, four light emitting sources and four light receiving elements are shown, but other numbers may be used as long as there are a plurality of light emitting elements and light receiving elements. However, the plurality of arrangements need not be arranged on the concentric rotation of the rotor.

  First, in FIG. 7A showing the state of the chamber immediately after the start of centrifugation, light is emitted from the light emitting units (A to D) and received by the light receiving units (1 to 4). Next, based on the amount of light received by each light receiving unit (1 to 4), the absorbance at each light receiving unit is calculated in the same manner as in the first embodiment. Since the plasma and blood cells are intermingled in the chamber immediately after the start of the centrifugation, the absorbance at the light receiving portions (1 to 4) is almost the same.

  Next, the state of the chamber after a predetermined time has elapsed is shown in FIG. At this time, light is again emitted from the light emitting units (A to D), received by the light receiving units (1 to 4), and the respective absorbances are calculated. The plasma and blood cells in the chamber are separated by the centrifugal force, so that plasma exists at the position where the light emitting part A and the light receiving part 1 are arranged, and blood cells exist at other positions. That is, there is a difference between the absorbance at the light receiving unit 1 and the absorbance at the light receiving units 2 to 4. Thereby, it turns out that the boundary position of plasma and a blood cell exists between the positions where the light emission part A and the light emission part B are arrange | positioned. Similarly, by calculating the absorbance at the four light receiving parts after a predetermined time has elapsed, it is possible to detect between the pair of each light emitting part and light receiving part where the boundary position between plasma and blood cells exists. In FIG.7 (c), there exists a boundary between the positions where the light emission part B and the light emission part C are arrange | positioned, and in FIG.7 (d), there exists a boundary on the left side from the position where the light emission part D is arrange | positioned. (It has passed through the position where the light emitting part D and the light receiving part 4 are arranged).

  As described above, the absorbance is measured (S62) and the boundary position between plasma and blood cells is detected (S63) by measuring the absorbance (S62) at a plurality of locations in the chamber 51 a plurality of times at predetermined time intervals. The centrifugal force control unit 59 controls the centrifugal force based on the result (S64).

  Specific control performed by the centrifugal force control unit 59 will be described with reference to FIG. The dots in the figure are graphs showing the relationship between the plasma volume required for the examination determined from the boundary positions of plasma and blood cells detected at time A, time B, and time C and the time required for centrifugation. The dotted line in the figure is the amount of plasma required for the examination, and the alternate long and short dash line is the required centrifugation completion time, which is a preset value. In FIG. 8 (a), the plasma volume at time C shows a value that is substantially close to the required plasma volume, and in view of changes in plasma volume at times A, B, and C, a preset centrifugation completion time is set. It is determined that the plasma volume that can be obtained in step 1 satisfies the required plasma volume, and there is no need to change the set centrifugal force. In FIG. 8 (b), the plasma volume at time C is less than half of the required plasma volume, and the change in plasma volume at time A, B, C is small, so at the preset centrifugation completion time, It can be determined that the necessary plasma volume is not satisfied, and the centrifugal force is increased by increasing the rotational speed of the motor 53 by the centrifugal force control unit 59. In FIG. 8C, since the plasma volume at time C exceeds the required plasma volume, the motor 53 is stopped by the centrifugal force control unit 59, and the measurement time can be shortened.

  Thus, depending on whether the necessary plasma volume has been obtained, the time given for the centrifugation process has elapsed, or whether the necessary plasma volume has not been obtained and it is determined that the analysis is impossible, the centrifugation process is performed. The process ends (S65). Subsequently, when the necessary plasma volume is obtained, reaction and analysis are executed (S66), and the blood analysis process is terminated. If the analysis is impossible, the blood analysis process is terminated without performing the reaction and the analysis.

  In addition, a plurality of light emitting units 55 and light receiving units 56 in the absorbance measurement unit 54 are not provided, but one movable light emitting unit and one light receiving unit are provided one by one, and the boundary is continuously detected and followed, thereby achieving high accuracy. Therefore, a movable light emitting unit and a light receiving unit may be provided one by one. In addition, it is better that the light emitting unit and the light receiving unit are arranged in the same direction as the direction in which the centrifugal force acts and at a linear fixed interval.

  The blood analyzer according to the present invention is capable of discriminating between normal plasma and abnormal plasma (chyle plasma or hemolyzed plasma) suitable for analysis by centrifuging blood, and can automatically determine the centrifugation necessary for measurement. It is useful for medical measuring instruments or bioanalytical instruments that require advanced centrifugation.

1 is a configuration diagram of a blood analyzer according to a first embodiment of the present invention. Flow chart of blood analysis processing in Embodiment 1 of the present invention Flowchart of specimen discrimination process that is a part of blood analysis process in Embodiment 1 of the present invention Schematic diagram of changes in blood sample in the chamber during centrifugation in Example 1 of the present invention Configuration diagram of blood analyzer according to Embodiment 2 of the present invention Flow chart of blood analysis processing in Embodiment 2 of the present invention Schematic diagram of change of blood sample in chamber and boundary detection during centrifugation in embodiment 2 of the present invention Schematic diagram of criteria for centrifugal force control in Embodiment 2 of the present invention Configuration diagram of a conventional centrifuge

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rotor 11 Chamber 12 Centrifugation control part 13 Motor 14 Absorbance measurement part 15 Light emission part 16 Light reception part 17 Calculation part 18 Sample discrimination | determination part 19 Analysis procedure control part S20-S25 Step S30 Step 40 Chamber 50 Rotor 51 Chamber 52 Centrifugation control part 53 Motor 54 Absorbance Measurement Unit 55 Light Emitting Unit 56 Light Receiving Unit 57 Calculation Unit 58 Boundary Detection Unit 59 Centrifugal Force Control Unit S60 to S66 Step 70 Chamber 90 Blood Analyzer 91 Centrifuge 92 Rotating Stage 93 Transfer Machine 94 Centrifuge 95 Rotation center

Claims (5)

A chamber for injecting blood for testing;
A centrifuge controller for applying a centrifugal force by rotating the chamber;
An absorbance measurement unit for measuring the absorbance of blood to be examined in the chamber after centrifugation;
A specimen discriminating unit for discriminating whether the blood to be examined is normal or abnormal according to the absorbance of plasma measured by the absorbance measuring unit;
A blood analysis apparatus comprising: an analysis procedure control unit that stops an analysis process when it is determined that the blood to be examined is abnormal. The blood analyzer according to claim 1, wherein the sample determination unit determines that an abnormality occurs when the absorbance of the blood to be tested exceeds a predetermined threshold. A chamber into which a blood sample can be injected;
A centrifuge controller for applying a centrifugal force by rotating the chamber;
An absorbance measurement unit for measuring the absorbance of blood to be examined in the chamber after centrifugation;
A boundary detection unit that determines a boundary position between plasma and blood cells during centrifugation based on a measurement result by the absorbance measurement unit and sets a boundary position signal;
A blood analysis apparatus comprising: a centrifugal force control unit that changes a centrifugal force of the centrifugal separation control unit based on the boundary signal. The absorbance measurement unit includes a plurality of light sources arranged to irradiate light to the blood measurement unit of the chamber and a plurality of light receiving elements arranged corresponding to the light sources, and applies centrifugal force to the chamber. The blood analyzer according to claim 3, wherein a light reception signal of the light receiving element is detected at a predetermined time interval and output to the boundary detection unit. The boundary detection unit comprises storage means for storing the output sent from the absorbance measurement unit, and calculation means for calculating the time change of the boundary position between plasma and blood cells during centrifugation based on the storage means, The blood analyzer according to claim 3, wherein the centrifugal force control unit outputs the result of the calculation means as a boundary position signal.

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