JP2002333449A - Sample dispensing apparatus and autoanalyzer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sample dispensing apparatus and an autoanalyzer using the same capable of specifying the cause of the abnormal suction occurring during dispensing a sample in a short time. SOLUTION: A pressure sensor 11 is connected to a dispensing flow path system including a sample probe 1 and a dispensing syringe 3 to measure a pressure variation waveform during dispensing the sample. The output from the pressure sensor 11 is sent to an integration operation circuit 15 through an amplifier 13 and an A/D converter 14. For respective plural integration intervals divided at least from the sample suction interval, the integration treatment is performed with a predetermined sampling frequency. The output from the integration operation circuit 15 is sent to a determination circuit 16. The determination circuit 16 previously stores threshold ranges corresponding to the plurality of integration operation results and compares them to determine whether the suction operation has been conducted normal or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample dispensing apparatus used for an automatic analyzer for analyzing a liquid sample such as blood or urine.

[0002]

2. Description of the Related Art For example, in an automatic analyzer such as a biochemical automatic analyzer or an immune automatic analyzer, a liquid sample is automatically sucked and discharged from a sample container to a reaction container (hereinafter, referred to as dispensing).
Sample dispensing device.

Conventionally, a sample dispensing apparatus has a sample probe, a dispensing syringe connected to the sample probe, and a mechanism for moving the sample probe to a predetermined position. The tip of the sample probe is inserted into a sample and dispensed. The dispensing operation of aspirating a predetermined amount of sample by driving the syringe by a predetermined amount, and thereafter moving the sample probe to the reaction container and discharging the sucked sample is repeated.

[0004] In a specimen test such as a biochemical test, serum or plasma is often used as a sample, and these often contain a solid substance called fibrin. If this sample is applied to an automatic analyzer as it is, the solid matter may clog the probe. When the sample probe is clogged as described above, a predetermined amount of the sample cannot be dispensed into the reaction container, and the analysis accuracy of the automatic analyzer is greatly deteriorated.

[0005] As means for solving such a problem,
Many proposals have been made in which a pressure sensor is provided in a dispensing flow path including a sample probe, and clogging of the probe is detected based on pressure fluctuation.

For example, Japanese Patent Application Laid-Open No. 2000-39440 discloses a technique for judging an abnormality in dispensing a sample based on a comparison between an area value obtained by integrating the output of a pressure sensor and a predetermined reference value. Have been.

[0007] Japanese Patent Laid-Open No. Hei 2 (1990) -1990 discloses a technique of comparing the output value of a pressure sensor with a predetermined reference value to monitor whether a liquid sample has been sucked as expected (whether or not a liquid sample has been sucked).
It is disclosed in Japanese Patent Publication No. 196963.

[0008]

According to the prior art, the output of the pressure sensor in the entire section from the start of suction to the end of suction is integrated, and the integrated value is compared with a predetermined reference value to determine abnormality. I have. Therefore, it was difficult to identify the cause of the abnormality. When an operator finds an abnormality, it is necessary to stop the device and visually examine the cause of the abnormality. In this case, the analysis must be stopped during the time required for investigating the cause, and there is a possibility that a problem such as a decrease in the analysis efficiency may occur.

A first object of the present invention is to provide a sample dispensing apparatus capable of specifying the cause of a suction abnormality in a short time and performing efficient analysis.

In recent automatic analyzers, it is required to reduce the amount of specimen per analysis as much as possible to reduce the burden on patients, especially children and the elderly, or to reduce the amount of reagents used. However, when the dispensing volume is reduced, the dispensing speed must be reduced to maintain the dispensing accuracy, and as a result, the pressure fluctuation in the dispensing channel becomes very small, making it difficult to make a determination based on the threshold. However, the above-mentioned conventional technology has not sufficiently examined such a problem.

A second object of the present invention is to provide a sample dispensing apparatus capable of detecting a suction abnormality with high accuracy even when a sample suction amount is very small.

[0012]

To achieve the above object, the present invention is configured as follows.

A sample probe for sucking and discharging the liquid sample, a dispensing syringe for generating pressure for sucking and discharging the liquid sample to the sample probe, and a dispensing flow connecting the sample probe and the dispensing syringe A pressure sensor for detecting a pressure in the dispensing flow path, and an integrating operation means for integrating an output of the pressure sensor in the sample dispensing apparatus having a flow path and a control unit for controlling a suction / discharge operation of a liquid sample. And dividing the sample suction time into a plurality of sections, calculating the integral value of the output of the pressure sensor for each of the divided sections by the integration calculating means, and calculating the integral value of the pressure sensor output of each section and each section. A sample dispensing apparatus including a determination unit that determines a suction abnormality of a liquid sample by comparing the threshold value with a predetermined threshold value.

In the sample dispensing apparatus, the divided section of the sample suction time is divided into the first half and the second half of the sample suction time, and the integral value of each section and a predetermined threshold value corresponding to each section are determined. In comparison, a determination means for determining a suction abnormality of the liquid sample may be provided.

Further, the control device may be configured to set a division section and a threshold value of the integral according to the dispensed amount of the liquid sample.

Further, according to the present invention, in the automatic analyzer provided with the above-mentioned sample dispensing apparatus, the control unit determines whether or not the suction of the liquid sample is abnormal based on the comparison result between the integral value of the pressure sensor and a predetermined threshold value. Is characterized by an automatic analyzer that has a function of classifying the cause into a plurality of causes and performing a countermeasure operation according to each cause.

In the above automatic analyzer, the countermeasure operation may include an operation of discharging the liquid sample once sucked and sucking it again.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The feature of the present invention as compared with the prior art is that, in short, the time from the start of suction of a liquid sample to the end of suction is divided into a plurality of times, and the integral of the pressure sensor output in each section Values and comparing the integrated value with a threshold value for each predetermined section. As a result, the cause of the abnormality can be identified in a short time, and in some cases, the abnormality can be automatically dealt with on the device side. Even if there is an abnormality, the abnormality is automatically repaired without the operator's knowledge. Thus, it is possible to provide an automatic analyzer that can continue analysis.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a sample dispensing apparatus according to a first embodiment of the present invention.

In FIG. 1, a sample probe 1 is connected to a dispensing syringe 3 via a tube 2, and the inside thereof is filled with a liquid. The dispensing syringe 3 includes a cylinder 3a and a plunger 3b, and a motor 4 is connected to the plunger 3b. Fix the cylinder 3a,
When the motor 4 is driven by the motor drive circuit 5, the plunger 3b is driven up and down, thereby performing a sample dispensing operation. The sample probe 1 can be moved to a predetermined position by driving the motor 6 by the motor drive circuit 7. The motor drive circuits 5 and 7 are controlled by the control unit 8.

When the sample probe 1 descends and reaches the liquid of the sample 10 in the sample container 9, the dispensing syringe 3 performs a suction operation by driving the motor 4. Similarly, after the sample probe 1 moves to the sample discharge position, the dispensing syringe 3 performs a discharge operation by driving the motor 4.

The pressure sensor 11 is connected via a branch block 12 to a sample probe 1, a tube 2, a dispensing syringe 3
Is connected to the dispensing flow path system containing. The output of the pressure sensor 11 is amplified by the amplifier 13 and is output from the A / D converter 14.
Is converted into a digital signal.

Further, the output of the A / D converter 14 is sent to an integration operation circuit 15. The integration operation circuit 15 performs an integration process at a predetermined sampling frequency. The integration section at this time is each of the sample suction section, that is, the driving section of the motor 4 divided into the first half and the second half (hereinafter, referred to as a first integration section and a second integration section, respectively). The integrated value of each section performed by the integration operation circuit 15 is sent to the determination circuit 16. The determination circuit 16 stores threshold ranges corresponding to each section in advance, compares them, and makes a determination described below to determine whether or not the suction operation has been performed normally. If abnormal suction is found, an alarm to that effect is issued.

Hereinafter, a method for judging a suction abnormality according to the present invention will be described.

According to the present invention, the value integrated in each section of the first integration section and the second integration section is used for the determination of the suction abnormality. This value corresponds to each area value of S1 and S2 in FIG. 4 in which the vertical axis indicates the pressure in the dispensing channel and the horizontal axis indicates time. Note that the pressure value in the sample suction section is actually negative, so that the integration operation is performed with the sign reversed.

Here, the first case where normal suction is performed is described.
Integration value S in integration section and second integration section
For 1 _Normal and S2 _Normal , each threshold range is
Over S1 _Low and below S1 _High , Over S2 _Low and S2 _High
Less than.

When both the values of S1 and S2 fall within the respective threshold ranges, that is, in the case as shown in FIG. 3A, it is determined that suction has been performed normally. When S1 is within the threshold range and S2 is equal to or higher than S2 _High , that is, FIG.
In the case of (b), it is considered that solid matter such as fibrin has clogged somewhere from just before the end of the first integration interval to the end of the second integration interval. Therefore, in this case, it is determined to be abnormal. Further, when both S1 and S2 exceed the respective threshold ranges, that is, in the case as shown in FIG. 3D, the inside of the sample probe is in the closed state, or the initial state of the first integration section is It is considered that solid matter such as fibrin was clogged at the stage. Therefore, also in this case, the abnormality is determined.

When both S1 and S2 fall below the respective threshold ranges, that is, in the case as shown in FIG. 3 (e), in an automatic analyzer equipped with a function for detecting the liquid level of the sample, the liquid level is reduced. It is conceivable that the suction operation is performed when the suction operation is started while erroneous detection is performed, or the empty suction is performed when the sample container and the sample are not originally arranged. Therefore, also in this case, the abnormality is determined. Also, when S1 is within the threshold range and S2 is equal to or less than S2 _Low ,
In the case of (g), the amount of the sample in the sample container is insufficient for the requested dispensing amount, or the detection is performed by an automatic analyzer equipped with a function for detecting the liquid level of the sample. It is conceivable that the depth of penetration from the liquid surface was insufficient and the liquid surface dropped to the tip of the sample probe during the suction operation. Also in this case, it is determined that a sufficient amount has not been sucked, and an abnormality is determined. Similarly, when S1 is higher than S1 _High but S2 is lower than S2 _Low , or S1 is higher than S1
If the value is higher than 1 _High , but S2 is within the threshold range, it is determined that there is an empty suction due to a shortage of the sample, and an abnormality is determined.

When S1 is equal to or less than S1 _Low and S2 is within the threshold range, that is, as shown in FIG. 3F, the function of detecting the liquid level of the sample and the suction operation while lowering the sample probe are performed. In an automatic analyzer equipped with a function to perform the operation, a suction operation may be started while the liquid level is erroneously detected, but the liquid level may be reached halfway and the sample may be suctioned. Also in this case, it is determined that there is an abnormality because there is no difference in the idle suction. When S1 is equal to or lower than S1 _Low and S2 is equal to or higher than S2 _High , it is determined that there is an abnormality for the same reason.

FIG. 5 summarizes the above-described suction abnormality determination method according to the present invention.

Next, a second embodiment will be described.

FIG. 2 is a schematic configuration diagram of a sample dispensing apparatus according to a second embodiment of the present invention.

The output of the pressure sensor 11 connected to the dispensing channel system including the sample probe 1 and the dispensing syringe 3 is sent to the microcomputer 17 via the amplifier 13 and the A / D converter 14. The microcomputer 17 performs the integral calculation processing and the suction abnormality determination processing.

Sample dispensing is performed in the following flow.

The control unit 8 sends a control command to the motor drive circuits 5 and 7 to start the dispensing operation. at the same time,
The command from the control unit 8 is also sent to the microcomputer 17 to activate the suction abnormality detecting function.

In response to a command from the control unit 8, the CPU 19
Information necessary for determining a suction abnormality from the OM 20, that is, a start time and a section length of the first integration section, a start time and a section length of the second integration section, and a threshold range corresponding to each section are stored in the RAM 21. call. At the timing of starting the integration, the CPU 19 starts the integration process on the output signal from the A / D converter 14. When the integration is completed and an operation result is obtained, the result is compared with a threshold range previously stored in the RAM 21 to make a determination. This is performed for the first integration section and the second integration section, and comprehensive determination is made by the suction abnormality determination method described above. The result is returned to the control unit 8, and based on the result, the control unit 8 makes a determination on the subsequent processing.

Incidentally, the start time and the section length of the sample suction section differ depending on the dispensed amount. This is because the dispensing sequence and the suction speed are changed depending on the dispensing amount in consideration of the dispensing processing speed and the dispensing accuracy.

Therefore, for all the dispensing amounts used for analysis, which are defined as specifications of the sample dispensing apparatus or the automatic analyzer equipped with the sample dispensing apparatus, each of the first integration section and the second integration section is used. Start time and section length are R
It is written on the OM 20 in advance.

Also, as with the integration interval, the threshold range differs for each dispensed volume, so that the threshold range corresponding to the first integration interval and the second integration interval for all the dispensed volumes used in the analysis. Is set and written in the ROM 20 in advance.

Note that the sampling frequency for the integration operation is also set in advance. This may be made variable instead of fixed regardless of the length of the integration interval. In any case, all the information or the program necessary for the determination of the suction abnormality is written in the ROM 20.

With the above configuration, even if the dispensed amount changes, an abnormal suction can be detected.

Hereinafter, an example of use in an automatic analyzer will be described. When the sample dispensing device is installed in the automatic analyzer, the control unit 8 may also serve as the control unit of the automatic analyzer. Hereinafter, it is assumed that the control unit 8 is a control unit of the automatic analyzer.

When the control unit 8 issues a series of dispensing commands specifying the dispensing amount and the dispensing frequency, the microcomputer 17
Determines whether suction has been performed normally for each dispensing, and reports the result to the control unit 8 one by one. Here, when it is determined that the operation is normal, the normal dispensing operation is continued.

As shown in FIG. 3B, when it is determined that the fibrin is clogged during the suction, there is a high possibility that the fibrin larger than the inner diameter of the sample probe 1 is merely caught on the tip thereof, and the sample is removed. It is considered that fibrin can be easily removed simply by discharging.
Therefore, the control unit 8 issues an instruction to discharge the sample to the reaction container, aspirate the sample again, and discharge the sample to another reaction container.

When abnormal suction occurs, the sample dispensed at that time is not analyzed, or
An instruction is sent to the automatic analyzer so as not to adopt the analysis result even if it is executed.

As shown in FIG. 3 (e), when it is determined that both the first integration interval and the second integration interval have exceeded the respective threshold ranges, the following cases are considered. The first case is when the inner wall of the sample probe 1 is closed. In this case, there is no other choice but to push out the clog in the sample probe 1 with high-pressure water or to insert a wire or the like inside to remove it. If it is determined that it cannot be removed without the help of the operator, the control unit 8 issues an alarm. The second case is a case where dispensing is performed on a sample having a significantly higher viscosity than a normal sample. Even if there is no clogging, it cannot be said that accurate dispensing was performed in such a case. Therefore, in such a case, it is desirable to change the dispensing conditions, that is, the dispensing amount and dispensing speed, and to perform the analysis again.

As shown in FIG. 3E, when it is determined that the empty suction has occurred due to the erroneous liquid level detection, the dispensing operation is performed again without waiting for the measurement result. In this case, since the bubble layer may continue to exist again during the sample dispensing operation, the control unit 8 controls each mechanism so as to increase the amount of the sample probe 1 penetrating the sample. The same applies to the case of FIG. 3F in which the sample is sucked by the lowering of the sample probe 1 in spite of the erroneous liquid level detection.

When the case shown in FIG. 3E appears continuously, it is considered that the sample container and the sample were not originally arranged in the automatic analyzer. In that case,
The control unit 8 issues an alarm to inform the operator that the sample container and the sample need to be placed.

As shown in FIG. 3 (g), when it is determined that the empty suction has occurred due to the shortage of the sample, the control unit 8 issues an alarm to notify the operator of the necessity of adding the sample.

As described above, according to the present invention, when an abnormal suction occurs during sample dispensing, not only can the abnormal suction be detected, but also the type and degree of the abnormality can be grasped. Can be provided with a judgment function for the processing of (1).

Note that, when a suction abnormality occurs, a measure taken to cope with the abnormality is not limited to the above-described means.

In the present invention, the sample aspiration section is divided into the first half and the second half as an integral section for determining a suction abnormality. However, it is also effective to divide the sample into three or more. It is also effective to provide an integration section immediately after suction and add the residual pressure immediately after suction to the determination condition.

Further, when some abnormality occurs during the suction of the sample, most of the effects also appear during the discharge of the sample. By utilizing this fact, an integral section is also provided in the sample discharge section, and this is added to the condition for judging a suction abnormality, so that abnormal suction can be determined more clearly.

[0055]

According to the present invention, it is possible to provide a sample dispensing apparatus capable of specifying the cause of the suction abnormality in a short time and performing efficient analysis.

Further, even if the dispensed amount changes, including a minute dispensing amount, a sample dispensing apparatus capable of operating the abnormal suction detection function corresponding thereto can be realized.

According to the fourth and subsequent aspects of the present invention, it is possible to provide the automatic analyzer with a function of judging a process when an abnormality occurs, so that the trouble of the operator is minimized. , The processing capacity can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a sample dispensing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a sample dispensing apparatus according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a pressure fluctuation waveform in a dispensing channel in a sample suction section.

FIG. 4 is a diagram showing an integration section in the present invention.

FIG. 5 is a diagram showing a method for determining a suction abnormality according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sample probe, 2 ... Tube, 3 ... Dispensing syringe, 3a ... Cylinder, 3b ... Plunger, 4, 6 ... Motor, 5, 7 ... Motor drive circuit, 8 ... Control part, 9 ... Sample container, 10 ... Sample , 11: Pressure sensor, 12: Branch block, 13: Amplifier, 14: A / D converter, 15: Integration operation circuit, 16: Judgment circuit, 17: Microcomputer, 18: I / O port, 19: CPU, 20… RO
M, 21 ... RAM.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsuhiro Kamihara 882, Momo, Oaza, Hitachinaka-shi, Ibaraki F-term in the Hitachi Measuring Instruments Group (reference) 2G052 AA30 AA32 AD06 BA14 CA02 CA28 CA38 HC25 JA11 2G058 EA02 EB01 ED21 GB06 GE09

Claims (5)

[Claims] 1. A sample probe for sucking and discharging a liquid sample, a dispensing syringe for generating a pressure for sucking and discharging the liquid sample to the sample probe, and a connection for connecting the sample probe and the dispensing syringe. In a sample dispensing device having a pouring channel and a control unit for controlling a suction / discharge operation of a liquid sample, a pressure sensor for detecting a pressure in the dispensing channel, and an integral for integrating an output of the pressure sensor Calculating means, dividing the sample suction time into a plurality of sections, calculating the integral value of the output of the pressure sensor for each of the divided sections by the integral calculating means, and calculating the integral value of the pressure sensor output in each section and each integral value. A sample dispensing device, comprising: a determination unit that determines a suction abnormality of a liquid sample by comparing a predetermined threshold value corresponding to a section with a threshold value. 2. The sample dispensing apparatus according to claim 1, wherein the divided section of the sample suction time is divided into a first half and a second half of the sample suction time, and an integral value of each section and a predetermined value corresponding to each section are set in advance. A sample dispensing device comprising: a determination unit that determines a suction abnormality of a liquid sample by comparing a predetermined threshold value. 3. The sample dispensing device according to claim 1, wherein the control device sets a division section and a threshold value of integration according to a dispensed amount of the liquid sample. apparatus. 4. An automatic analyzer provided with the sample dispensing device according to claim 1, wherein an abnormality in aspiration of the liquid sample is determined by comparing a section integral value of the pressure sensor with a predetermined threshold value. An automatic analyzer, characterized in that the control unit classifies the cause into a plurality of causes based on a comparison result, and has a function of performing a countermeasure operation according to each cause. 5. The automatic analyzer according to claim 4, wherein the countermeasure operation includes an operation of discharging the liquid sample once aspirated and aspirating the liquid sample again.