JP2018185145A - Automatic analyzer and dispensing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an automatic analyzer capable of detecting a liquid surface position with high accuracy regardless of the presence or absence of a lid of a specimen or a reagent container and improving dispensing accuracy of specimens and reagents.SOLUTION: A nozzle is lowered toward a liquid surface, the electrostatic capacity detected during a lowering operation is stored in a memory, and the lowering operation is stopped when it is determined that the nozzle has been lowered by a set lowering amount (steps S10 to S20). The presence or absence of liquid is determined based on the electrostatic capacity stored in the memory at a lid height of a reagent container, and abnormality processing is performed when it is determined that there is liquid (steps S20b, S80a). A suction operation of reagents is performed when it is determined in the step S20b that there is no liquid. Determination processing of a pressure value of a pressure sensor and determination processing of an electrostatic capacitance value are performed, and it is determined to be normal only when it is determined that there is no abnormality such as idle suction on the basis of the pressure waveform and that there is a liquid surface (step S50a). The abnormality processing such as occurrence of an alarm is performed when it is determined to be abnormal in the step S50a (step S80).SELECTED DRAWING: Figure 10

Description

  The present invention relates to an automatic analyzer and a dispensing method.

  An automatic analyzer that analyzes components such as blood and urine chemically reacts a liquid sample dispensed in a reaction vessel with a reagent, irradiates the reaction solution with light using a halogen lamp, etc., and measures the absorbance to measure the liquid sample. Analyze ingredients.

  A nozzle is used to dispense a sample or reagent into a reaction container. This nozzle also functions as a probe for detecting the liquid level in the specimen or reagent container. When detecting the liquid level using a change in capacitance, this probe functions as an electrode.

  Sample containers and reagent containers with lids may be used, but if liquid adheres to the lid, the probe will come into contact with the liquid and the lid part will be mistakenly determined as the liquid level. There are known issues. In order to prevent this erroneous detection, a technique for determining a stop range for stopping the detection function of the detection unit and stopping the detection function of the detection unit until the suction pipe falls below the stop range is disclosed (Patent Document 1). .

JP 2008-046033 A

  When a dispensing operation is performed on a specimen container or a reagent container with a lid, a straight nozzle having no shield part is used for the purpose of ensuring structural strength and optimizing manufacturing costs. In a structure without a shield part, the entire length of the nozzle functions as an electrode, so the detection level is the same as when the capacitance detection signal detects the liquid level when the nozzle contacts the sample or reagent liquid attached to the lid. Then, even if the nozzle descends and the tip of the nozzle comes into contact with the liquid level in the container, the signal level may not change sufficiently. As described above, since the liquid level detection is performed based on the change in the capacitance value, even if the nozzle is in contact with the liquid level, it is determined that the nozzle is in contact with the liquid level if there is no change in the capacitance. Can not.

  For this reason, only with the technique of stopping the detection function of the detection unit, as described above, when there is almost no change in the capacitance value, it may not be possible to perform highly reliable liquid level detection.

  Therefore, when a container with a lid is used, there is an example using a dispensing technique that does not rely on capacitance detection. In this example, the presence or absence of liquid is determined using the suction pressure signal of the nozzle. However, when registering the remaining amount of the reagent, it is necessary to consume the reagent for the convenience of using the pressure signal. For safety reasons, it is necessary to set the distance to enter the liquid surface deeper, and there are restrictions such as increasing the amount of sample or reagent attached to the nozzle and extending the cleaning time. .

  On the other hand, it is very difficult to find a handling operation in which the liquid inside does not adhere to the lid with respect to the reagent or specimen container.

  An object of the present invention is to realize an automatic analyzer and a liquid dispensing method capable of detecting the position of a liquid surface with high accuracy regardless of the presence or absence of a lid of a sample or reagent container and improving the dispensing accuracy of the sample or reagent. That is.

  In order to achieve the above object, the present invention is configured as follows.

  In an automatic analyzer, a liquid is aspirated from a reaction mechanism in which a reaction container is arranged, a spectroscope for analyzing a sample in the reaction container arranged in the reaction mechanism, and a liquid container containing a liquid that is a reagent or a sample. , A liquid dispensing nozzle that discharges to a reaction vessel disposed in the reaction mechanism, a capacitance detection mechanism that detects a capacitance value of the liquid dispensing nozzle, and a pressure that detects a pressure in the liquid dispensing nozzle A liquid dispensing mechanism having a sensor; and a control unit that controls operations of the reaction mechanism, the spectroscope, and the liquid dispensing mechanism.

  The control unit includes a nozzle position determination unit that determines the position of the liquid dispensing nozzle, a pressure determination unit that determines a pressure value from the pressure sensor, and a capacitance detected by the capacitance detection mechanism. Based on the determination of the liquid level detection unit that detects the liquid level of the liquid, the nozzle position determination unit, the pressure determination unit, and the liquid level detection unit, whether the operation of the liquid dispensing mechanism is normal or abnormal is determined. A normal / abnormal determination unit for determining, and an operation command unit for instructing the operation of the liquid dispensing mechanism based on the determination of the normal / abnormal determination unit.

  Further, in the liquid dispensing method in the automatic analyzer, the liquid dispensing nozzle that sucks and discharges the liquid that is the reagent or the sample is moved down toward the liquid container that stores the liquid, and the liquid dispensing nozzle The position is determined by the nozzle position determination unit, and the capacitance value of the liquid dispensing nozzle is detected. Based on the detected capacitance value, the liquid dispensing nozzle reaches the liquid level of the liquid. When the liquid dispensing nozzle is stopped, and the liquid dispensing nozzle is at the height of the liquid container, the detected capacitance value is the liquid dispensing nozzle. When the nozzle does not indicate that the liquid level has been reached, the liquid dispensing nozzle sucks the liquid in the liquid container, detects the capacitance value of the liquid dispensing nozzle, and Liquid dispensing The pressure in the nozzle is detected, and the detected capacitance value of the liquid dispensing nozzle indicates that the liquid dispensing nozzle is in contact with the liquid surface of the liquid, and the detected liquid dispensing When the pressure in the nozzle indicates that the liquid dispensing nozzle is in contact with the liquid surface of the liquid, the liquid dispensing nozzle is moved upward.

  Further, in the liquid dispensing method in the automatic analyzer, the liquid dispensing nozzle that sucks and discharges the liquid that is the reagent or the sample is moved down toward the liquid container that stores the liquid, and the liquid dispensing nozzle The position is determined by the nozzle position determination unit, and the capacitance value of the liquid dispensing nozzle is detected. Based on the detected capacitance value, the liquid dispensing nozzle reaches the liquid level of the liquid. When the liquid dispensing nozzle is stopped, the position where the liquid dispensing nozzle is stopped and the position of the liquid dispensing nozzle determined by the nozzle position determination unit are determined. In comparison, it is determined whether or not the stopped position is lower than the height of the liquid container, and when it is determined that the stopped position is lower than the height of the liquid container, the liquid dispensing nozzle When the capacitance value is detected and it is determined that the liquid dispensing nozzle has reached the liquid level based on the detected capacitance value, the liquid dispensing nozzle is moved up by the nozzle vertical drive mechanism. The nozzle descending amount is calculated based on the nozzle position determined by the nozzle position determining unit, the liquid level in the liquid container is obtained, and the remaining liquid amount is registered in the memory.

  Regardless of the presence or absence of the lid of the specimen or reagent container, it is possible to realize an automatic analyzer and a liquid dispensing method capable of detecting the liquid surface position with high accuracy and improving the dispensing precision of the specimen or reagent.

It is a figure which shows schematic structure of the automatic analyzer which concerns on Example 1 of this invention. It is explanatory drawing of two types of reagent containers. It is an enlarged view of a reagent dispensing mechanism. It is a functional block diagram about the dispensing operation | movement of the dispensing mechanism in a control part. It is a residual amount registration operation | movement flowchart of the reagent in a container without a lid | cover in the technique different from this invention. It is a residual amount registration operation | movement flowchart of the reagent in the container with a lid | cover in a technique different from this invention. It is a reagent residual registration operation | movement flowchart in Example 1 of this invention. It is an aspiration operation | movement flowchart of the reagent in a container without a lid | cover in the technique different from this invention. It is an aspiration operation | movement flowchart of the reagent in the container with a lid | cover in a technique different from this invention. It is a reagent aspiration operation | movement flowchart in Example 2 of this invention. It is a graph which shows the change of an electrostatic capacitance value when descend | falling toward a reagent container with a lid | cover in the case of the nozzle which has a shield site | part. It is a graph which shows the change of an electrostatic capacitance value when descend | falling toward a reagent container with a lid | cover in the case of a nozzle without a shield part. It is explanatory drawing of the determination logic which combined the liquid level detection by an electrostatic capacitance, and the idle suction detection by a pressure determination.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

(Example 1)
FIG. 1 is a diagram showing a schematic configuration of an automatic analyzer according to Embodiment 1 of the present invention.

  The automatic analyzer sets a transport line 101 and a rack rotor 102 for transporting a sample container (sample container) 110 containing a liquid sample (for example, a sample such as blood or urine), and a reagent container 113 corresponding to the measurement item. A reaction disk (reaction mechanism) 100 having a reaction vessel 104 for maintaining the reaction vessel 112 at a constant temperature. A stirring mechanism 106 for stirring the reaction in order to stabilize the reaction between the poured liquid sample and the added reagent, a spectroscope 107 for measuring the absorbance of the reaction liquid, and a cleaning mechanism for sucking and washing the waste liquid in the reaction vessel 112 108, Nozzle cleaning mechanism 109 for cleaning the nozzle outer wall, a part of the liquid sample or reagent is collected (suctioned (dispensed)) from the container, and the reaction container Sample or reagent dispensing nozzles 116a, 116b to be discharged (dispensed) to 12, capacitance detection mechanisms 117a, 117b for detecting the liquid level of the sample, control of these mechanisms, calculation of analysis results, etc. The control part 115 to perform is provided. In the present application, the capacitance value of the nozzle is a capacitance value between the nozzle and the housing (GND) of the automatic analyzer.

  The sample container 110 is placed on the sample rack 111 and is transported by the transport line 101. FIG. 1 shows an example of a transport line type automatic analyzer, but the present invention can also be applied to a disk type automatic analyzer.

  The automatic analyzer includes dispensing mechanisms 105a and 105b that cause the nozzle 116 (116a and 116b) to suck and discharge the liquid sample and the liquid reagent. The dispensing mechanism 105 (105a, 105b) moves the system water filled in the nozzle 116, and causes the nozzle 116 to suck and discharge the liquid through the segmental air. The dispensing mechanism 105 includes a syringe for moving the system water, and the movement is performed by driving the syringe. The dispensing mechanism 105 also includes a drive mechanism such as a motor that causes the nozzle 116 to drive up and down and rotate.

  Next, a sample analysis method in the automatic analyzer will be described.

  In the automatic analyzer, the sample and the reagent, which are liquid samples, are dispensed into the reaction vessel 112, and the sample is analyzed using the change in absorbance of the reaction solution reacted in the reaction vessel 112. First, a specimen such as blood to be analyzed is held in a specimen container 110, and this specimen is dispensed into a reaction container 112 by a nozzle 116.

  On the other hand, the reagent is held in the reagent container 113, and this reagent is dispensed into the reaction container 112 by a nozzle 116 different from the sample. Then, the reaction liquid is agitated, and the reaction liquid is irradiated with light from a light source, and the spectroscope 107 receives this light. The absorbance is calculated from the received light, and the control unit 115 calculates the concentration of a predetermined item included in the sample from the change in absorbance.

  A reagent registration method in the automatic analyzer configured as described above will be described. FIG. 2 is an explanatory diagram of two types of reagent containers, and FIG. 3 is an enlarged view of the reagent dispensing mechanism 105.

  2A is a cross-sectional view of the reagent container 203 without a lid, and FIG. 2B is a cross-sectional view of the reagent container 204 with a lid. The lid 204a of the lidded reagent container 204 is made of a material having water repellency and insulating properties, such as polypropylene, with the inner portion of the lid projecting downward and the container material made of polypropylene. Thereby, the liquid adhering to the lid 204a does not remain as a liquid film, but is quickly separated from the reagent on the inner wall, and the structure of the reagent container 206 in a state where the inside of the lid in FIG. It is considered to be.

  Next, in FIG. 3, the dispensing mechanism 105 includes a capacitance detection mechanism 117 (117 a, 117 b), and the capacitance detection mechanism 117 is a circuit that converts the capacitance of the nozzle 116 into a voltage. The conversion voltage increases as the capacitance increases. The electrostatic capacity detection mechanism 117 stores a threshold value, and issues a liquid level detection signal when the electrostatic capacity exceeds the threshold value. This threshold is set as a voltage obtained by adding a certain value to the capacitance when the nozzle 201 is positioned in the air. For example, a position sensor is arranged at the highest upper limit point in the height direction of the nozzle 201, and a sample voltage is held by adding a constant voltage to the capacitance conversion voltage at the timing when the upper limit point position sensor is deviated by the descending operation. The threshold is used.

  Further, the pipe connected to the nozzle 201 is provided with a pressure sensor 202 for observing a pressure change in the pipe (the pressure sensor 202a is provided in the dispensing mechanism 105a, and the pressure sensor 202b is provided in the dispensing mechanism 105b. Are connected, and the suction state such as clogging in the nozzle 201 is checked and piping abnormality is monitored.

  Although not shown in FIG. 3, the dispensing mechanism 105 includes a nozzle up / down drive mechanism 118 (shown in FIG. 4) that moves the nozzle 116 up and down.

  As described above, there are two types of reagent containers, the container 203 with a lid and the container 204 without a lid. In the case of the reagent container 203 with a lid, a hole is formed in the lid with a needle-like mechanism in advance in the automatic analyzer. The action of opening the is performed. Further, in the reagent container 204 with a lid, there are roughly two types, a state 206 in which the inside of the lid is not wet with the reagent and a state 207 in which the inside of the lid is wet and is electrically connected to the reagent main body 205. Exists.

  FIG. 4 is a functional block diagram of the dispensing operation of the dispensing mechanism 105 in the control unit 115. In the functional block diagram shown in FIG. 4, functions other than the dispensing operation of the dispensing mechanism 105 are omitted.

  4, the control unit 115 includes a liquid level detection unit 115a that detects whether the nozzle 116 (201) has reached the liquid level from a change in the capacitance conversion voltage value from the capacitance detection mechanism 117; A pressure determination unit 15c that determines a pressure change in the nozzle 116 based on a pressure signal from the pressure sensor 202, and a nozzle that determines the position of the nozzle based on a drive signal from a nozzle vertical drive mechanism 118 included in the dispensing mechanism 105. A position determination unit 115e.

  The nozzle position determination unit 115e can also be configured to determine the position of the nozzle based on a signal from a separately installed position sensor.

  The control unit 115 further performs normal dispensing operation of the dispensing mechanism 105 based on the memory 115b in which various data are stored, the determination results of the liquid level detection unit 115a, the pressure determination unit 115c, and the nozzle position determination unit 115e. A normal / abnormal determination unit 115d is provided for determining whether or not the operation has been performed.

  Further, the control unit 115 includes an operation command unit 115f that supplies a command signal to the suction / discharge drive mechanism 120 and the nozzle vertical drive mechanism 118 of the dispensing mechanism 105 according to the determination result of the normal / abnormal determination unit 115d.

  In addition, the operation command unit 115f instructs the display unit 119 to display the occurrence of an abnormality. Note that the display unit 119 is omitted in FIG.

  For comparison between the first embodiment of the present invention and a technique different from the present invention, the operation of registering the remaining amount of the reagent in the lidless container in the technique different from the present invention will be described.

  FIG. 5 is a flowchart of the operation for registering the remaining amount of reagent in the lidless container 203 according to a technique different from the present invention.

  (1) In step S1 of FIG. 5, the nozzle 201 (116) rotates on the reagent container 203 and descends toward the liquid level.

  (2) In step S2, when the capacitance change exceeds the threshold value during the lowering of the nozzle 201, a stop signal is issued and the lowering operation is stopped.

  (3) In step S3, after the nozzle lowering operation is stopped, the liquid level detection signal is reconfirmed.

  (4) If the liquid level detection signal is not confirmed in step S3, it is determined that the capacitance change in step S2 is caused by bubbles or the like, and the process proceeds to step S6 to perform an abnormal process such as generating an alarm.

  (5) If the liquid level detection signal is confirmed in step S3, it is assumed that the reagent liquid level has been stopped normally, and the level rises to the upper limit in step S4. Obtain the liquid level and register the number of times the reagent can be tested.

  The operation example shown in FIG. 5 has the following characteristics.

  (A) The amount of nozzles entering the liquid is minimized.

  (B) Abnormal processing determination can be performed for bubbles that break.

  (C) No reagent is consumed in the remaining amount registration operation.

  Next, an operation for registering the remaining amount of reagent in a container with a lid according to a technique different from the present invention will be described.

  FIG. 6 is a flowchart for the operation of registering the remaining amount of reagent in the lidded container 204 according to a technique different from the present invention.

  (1) In step S1 of FIG. 6, the nozzle 201 rotates on the reagent container 203 and descends into the liquid.

  (2) In step S2a, the nozzle 201 stops after being lowered to the specified position, and a suction operation is performed.

  (3) In step S3a, the pressure in the nozzle 201 is confirmed, and it is determined from the pressure fluctuation waveform in the pipe that is being sucked whether or not idle suction has occurred, that is, the presence or absence of liquid.

  (4) If it is determined in step S3a that there is no liquid, the process proceeds to step S6, and abnormal processing such as generation of bubbles or generation of an alarm due to insufficient filling amount is performed.

  (5) If it is determined in step S3a that there is a liquid, the upper limit is raised in step S4, and the testable number of times (reagent remaining amount) of the reagent according to the filling amount of the reagent is stored in step S5. 115b is registered.

  The operation example shown in FIG. 6 has the following characteristics.

  (A) By taking into account variations in the initial filling amount and container shape, the amount of nozzle penetration into the liquid becomes deeper than in the liquid level detection method.

  (B) Abnormal processing determination can be performed even for bubbles that do not break.

  (C) Consumption of the reagent is necessary with the remaining amount registration operation.

  (D) Since the suction operation is performed, the processing time is longer than that in the liquid level detection method.

  Next, the reagent remaining amount registering operation according to the first embodiment of the present invention will be described with reference to FIG. FIG. 7 is a flowchart of the reagent residue registration operation according to the first embodiment of the present invention.

  (1) In step S1, the nozzle 116 (201) rotates on the reagent container 203 or 204 according to a command from the operation command unit 115f, and the nozzle 116 (201) is moved to the reagent container by the nozzle vertical drive mechanism 118. Go down.

  (2) In step S2, when the liquid level detection unit 115a determines that the capacitance has changed based on the signal from the liquid level detection mechanism 117, the operation command unit 115f receives the liquid level from the liquid level detection unit 115a. The operation of the nozzle vertical drive mechanism 118 is stopped by the detection signal.

  (3) In step 2b, the nozzle position determination unit 115e determines the position where the nozzle has stopped based on the operation (history) of the nozzle vertical drive mechanism.

  When the normality / abnormality determination unit 115d determines that the nozzle stop position (stop height) determined by the nozzle position determination unit 115e is the lid position (lid height) of the reagent container stored in the memory 115b in advance. The normal / abnormality determination unit 115d determines that there is an abnormality, and the process proceeds to step S6b where an abnormality process is performed.

  When it is treated as the abnormal process, the following recovery operation shown in step S7 is performed.

  (A) The registration operation of the corresponding reagent container (reagent container determined to be abnormal) is postponed and the registration operation is performed again. This is because it is expected that the reagent adhering to the lid falls after a lapse of a certain time, and the capacitance change amount at the lid portion is expected to decrease.

  (B) A message indicating that the reagent container cannot be registered is displayed on the screen of the display unit 119.

  (C) Registration is performed by a reagent registration operation for a container with a lid. That is, the pressure determination unit 115c determines the pressure detected by the pressure sensor 202 by the same operation as that shown in FIG. 6, and performs the reagent registration operation. In this case, processing changes such as an increase in the amount of reagent that cannot be used and a reduction in operation acceleration are involved.

  Note that it may be effective to combine the above abnormal processes.

  Which of the three abnormal processes described above is to be performed can be determined in advance by the judgment of an operator or the like.

  (4) In step 2b, the nozzle stop position (stop height) determined by the nozzle position determination unit 115e is lower than the lid position (lid height) of the reagent container previously stored in the memory 115b. If it is determined, the process proceeds to step S3b. In Step 3b, the liquid level detection unit 115a determines whether or not the nozzle has reached the liquid level from the capacitance value from the capacitance detection mechanism 117, and if not, proceeds to Step 6c. The normal / abnormal determination unit 115d determines that the detection is erroneous due to the influence of bubbles, and performs an abnormality process such as displaying an alarm on the display unit 119 by the operation command unit 115f.

  (5) If the liquid level detection unit 115a determines in step S3b that the nozzle has reached the liquid level, the nozzle is raised to the upper limit in step S4, and in step S5, the nozzle position determination unit 115e. The nozzle lowering amount is calculated based on the nozzle position determined by the above step, the liquid level height of the reagent in the reagent container is obtained, and the number of reagent tests (reagent remaining amount) corresponding to the filling amount is registered in the memory 115b. To do.

  According to the first embodiment of the present invention, an automatic analyzer capable of detecting the liquid surface position with high accuracy and improving the reagent dispensing accuracy regardless of the presence or absence of the lid of the reagent container. In addition, a reagent dispensing method (reagent registration method) can be realized.

  Furthermore, according to the first embodiment of the present invention, the following features are provided.

  (A) The amount of nozzles entering the liquid can be kept to a minimum even for a container with a lid.

  (B) Abnormal processing determination can be performed even for bubbles that break.

  (C) No reagent is consumed in the remaining amount registration operation.

  In Example 1 of the present invention, when the nozzle stops below the lid of the reagent container, if the capacitance has increased to the vicinity of the threshold at the lid portion, not the reagent liquid level but the surroundings Since there is a concern that the liquid level may be erroneously detected due to the increase in capacitance due to the influence of the structure, it is necessary to consider this increase when determining the threshold value.

(Example 2)
Next, a second embodiment of the present invention will be described. In the second embodiment, the schematic configuration of the automatic analyzer, the schematic configuration of the dispensing mechanism 105, the configuration of the reagent containers 203 and 204, and the schematic functional block of the control unit 115 are the same as those in the first embodiment. Detailed description will be omitted.

  Example 2 is an example when the present invention is applied to a reagent aspirating operation.

  For comparison between the second embodiment of the present invention and a technique different from the present invention, a reagent aspirating operation in a lidless container according to a technique different from the present invention will be described.

  FIG. 8 is a flowchart of a reagent aspirating operation in the lidless container 203 in a technique different from the present invention.

  (1) In step S10 of FIG. 8, the nozzle 201 (116) rotates on the reagent container 203 and descends toward the liquid level. The lowering amount of the nozzle 201 is set according to the remaining amount of the reagent.

  (2) In step S20, the vehicle is lowered to the set lowering amount, and when it reaches the specified position, the lowering operation is stopped.

  (3) In step S30, the liquid level status indicating whether or not the electrostatic capacity value has changed and the liquid level has been detected is confirmed. If the liquid level is not detected, it is determined that there is no liquid, and the process proceeds to step S80 to perform an abnormality process such as generating an alarm.

  (4) If it is determined in step S30 that the liquid level has been detected, the process proceeds to step S40 to perform a reagent aspirating operation.

  (5) Next, in step S50, the capacitance value is detected, and the liquid level status at that time is confirmed. If the liquid level is not detected, the process proceeds to step S80, and an abnormal process such as generating an alarm is performed.

  (6) If the liquid level is detected in step S50, the upper limit is raised in step S60, and the next operation such as rotational movement on the reaction vessel 112 is performed in step S70.

  The operation example shown in FIG. 8 has the following characteristics.

  (A) The presence / absence of idle suction is checked by the liquid level detection signal.

  (B) An accurate check can be performed as long as there are no bubbles that do not disappear.

  (C) During the analysis operation, the reagent disk 103 rotates at a high speed, so that the liquid level detection is not stopped in consideration of the settling time of the reagent liquid shaking.

  Next, a reagent aspirating operation in a container with a lid in a technique different from the present invention will be described.

  FIG. 9 is a flowchart of a reagent aspirating operation in the lidded container 204 according to a technique different from the present invention.

  (1) In step S10 of FIG. 9, the nozzle 201 (116) rotates on the reagent container 203 and descends toward the liquid level. The lowering amount of the nozzle 201 is set according to the remaining amount of the reagent.

  (2) In step S20a, the vehicle descends to the set descending amount, and when it reaches the specified position, the descending operation is stopped and the suction operation is started.

  (3) Next, in step S3a, the pressure in the nozzle 201 is confirmed, and it is determined whether or not idle suction has occurred from the pressure fluctuation waveform in the pipe during suction, that is, the presence or absence of liquid.

  (4) If it is determined in step S3a that there is no liquid, the process proceeds to step S6, and abnormal processing such as generation of bubbles or generation of an alarm due to insufficient filling amount is performed.

  (5) If it is determined in step S3a that there is liquid, the next operation such as rising to the upper limit in step S4 and rotating on the reaction vessel 112 is performed in step S70.

  In the operation example shown in FIG. 9, this operation has the following characteristics.

  (A) The presence or absence of idle suction is checked with the pressure signal.

  (B) Although the state of complete idling can be detected, the detection accuracy is not high in cases such as idling in the middle of aspiration.

  (C) Bubbles may also be detectable.

  In addition, it is estimated that the determination difficulty by pressure tends to increase with a low dispensing amount and high-speed operation.

  Next, the reagent aspirating operation according to the second embodiment of the present invention will be described with reference to FIG. FIG. 10 is a flowchart of a reagent aspirating operation according to the second embodiment of the present invention.

  (1) In step S 10 of FIG. 10, the nozzle 201 (116) rotates on the reagent container 203 or 204 and is lowered toward the liquid level by the nozzle vertical drive mechanism 118. The lowering amount of the nozzle 201 is set according to the liquid level height dimension stored in advance in the memory 115b of the reagent container.

  (2) Next, in step S10a, the capacitance detected by the capacitance detection mechanism 117 during the lowering operation of the nozzle 201 is stored in the memory 115b via the liquid level detection unit 115a. The detected capacitance value is stored in the memory 115b corresponding to the nozzle position determined by the nozzle position determining unit 115e.

  (3) Next, the process proceeds from step S10a to step S20, and it is determined by the nozzle position determination unit 115e that the nozzle 201 is lowered by the set lowering amount and has reached the specified position (liquid level height dimension). Then, the descent operation is stopped.

  (4) Proceeding from step S20 to step S20b, the presence or absence of liquid is determined based on the detection signal from the capacitance detector 117 at the lid height in the case of the reagent container 204 with lid stored in the memory 115b. Is judged.

  (5) If the normal / abnormality determination unit 115d determines that the liquid is present in step S20b, the process proceeds to step S80a, and an abnormality process such as executing the operation shown in FIG. 9 from step S10 or generating an alarm is performed. Do.

  In step S80a, the selection of whether to perform the operation shown in FIG. 9 or to perform an abnormal process such as generating an alarm can be set in advance by an operator or the like.

  (6) In step S20b, when the normal / abnormality determination unit 115d determines that there is no liquid, the process proceeds to step S40, and the suction / discharge driving mechanism 120 performs a reagent suction operation.

  (7) Subsequently, the process proceeds from step S40 to step S50a, the pressure determination unit 115c determines the pressure value from the pressure sensor 202, and the liquid level detection unit 115a determines the capacitance value using the capacitance detection mechanism 117. Is done.

  In step S50a, it is determined that the pressure waveform is normal only when the pressure waveform is determined by the pressure determination unit 115c, there is no abnormality such as idle suction, and the liquid level detection unit 115a determines that the liquid level is present. The unit 115d determines.

  In step S50a, if the normal / abnormality determination unit 115d determines that there is an abnormality, the process proceeds to step S80 to perform an abnormality process such as generating an alarm.

  (8) If it is determined in step S50a that the normal / abnormality determination unit 115d is normal, the process proceeds to step S60, and the nozzle 201 is raised to the upper limit by the nozzle vertical drive mechanism 118. In step S70, the next operation such as rotational movement on the reaction vessel 112 is performed.

  Here, in step S20b, when the normal / abnormality determination unit 115d determines that there is liquid, the process proceeds to step S80a, and the reason for performing abnormality processing such as a liquid level detection operation by pressure will be described.

  FIG. 11 is a graph showing a change in capacitance value when descending toward a lidded reagent container in the case of a nozzle having a shield part. The vertical axis in FIG. 11 indicates the capacitance value between the tip of the nozzle and GND, and the horizontal axis indicates the lowered position of the nozzle tip. This descending position corresponds to the number of descending pulses commanded to the nozzle vertical drive mechanism 118 from the operation command unit 115f.

In FIG. 11, when the capacitance value when the nozzle is not in contact with the lid (cap) of the reagent container or the like is C ₀ , the capacitance value C ₁ when the nozzle is in contact with the cap (position P1). (> C ₀ ). Then, when the nozzle is in contact with the liquid surface becomes (position P2), the capacitance value _C 2 (> _{C 1).} The liquid level determination threshold value is C _t , and this liquid level determination value C _t can be set between the capacitance amounts C ₁ and C ₂ .

  For this reason, in the case of a nozzle having a shield part, it can be determined by detecting the capacitance value that the nozzle has reached the liquid level even if the liquid is attached to the cap.

  FIG. 12 is a graph showing a change in capacitance value when descending toward the lidded reagent container in the case of a nozzle having no shield part. The vertical axis in FIG. 12 indicates the capacitance value between the nozzle tip and GND, as in FIG. 11, and the horizontal axis indicates the lowered position of the nozzle tip. This descending position corresponds to the number of descending pulses commanded to the nozzle vertical drive mechanism 118 from the operation command unit 115f.

12, when the capacitance value when the nozzle is not in contact with the lid (cap), or the like of the reagent containers to C _0, if the nozzle is brought into contact with the cap (position P1), the capacitance value liquid considered to be equivalent to C ₂ to have reached the surface. The capacitance value C ₂ is larger than the liquid level determination threshold value C _t, also reaches the liquid surface nozzle is lowered, the detection of the electrostatic capacitance value, to detect the liquid level reaches the nozzle Can not.

  For this reason, in the case of a nozzle that does not have a shield part, it is difficult to determine that the nozzle has reached the liquid level when the capacitance is detected when the liquid adheres to the cap.

  Therefore, in Example 2 of the present invention, when the capacitance value at the lid height of the reagent container is determined and a liquid is detected, a liquid level determination operation based on pressure is performed or abnormal processing is performed.

  Next, a description will be given of the determination of normality only when it is determined in step S50a that there is no abnormality such as idling due to the determination of the pressure waveform and the liquid level detection unit 115a determines that the liquid level is present.

  FIG. 13 is an explanatory diagram of determination logic that combines liquid level detection based on capacitance and idle suction detection based on pressure determination.

  In FIG. 13, the cause of the case where it is determined that there is no empty suction (OK) in the pressure determination without detecting the liquid level based on the capacitance ((a) in FIG. 13) is the determination of the liquid level determination based on the capacitance. Abnormalities are considered. In addition, there is a case where the capacitance changes due to the pressure determination operation and it is determined that there is no liquid level even though there is no liquid level ((b) in FIG. 13). It can be avoided by setting to.

  Next, although there is liquid level detection based on electrostatic capacity, the cause of the case where it is determined that the pressure is determined to be vacant (NG) is that when bubbles are sucked ((c) in FIG. 13) and the pressure A case of a determination error ((d) in FIG. 13) can be considered. In the case of a pressure judgment error, it should be judged as abnormal, but there may be room for eliminating the pressure judgment error, so in order to distinguish it from abnormalities in other patterns, the data is output, and It may be possible to add a flag.

  In Example 2 of the present invention, it is determined to be normal only when there is liquid level detection and it is determined that there is no idling in the pressure determination.

  According to the second embodiment of the present invention, an automatic analyzer and a reagent dispenser capable of detecting the liquid surface position with high accuracy and improving the reagent dispensing accuracy in the reagent aspirating operation regardless of the presence or absence of the lid of the reagent container. An ordering method can be realized.

  In Example 2 of the present invention, when both the liquid level detection signal and the pressure signal can be used, there is a concern about erroneous detection of bubbles only by the liquid level detection method and empty suction from the middle only by the pressure signal method. Both can be eliminated.

  In addition, the second embodiment can be applied to both the sample and the reagent during the analysis operation in the automatic analyzer, and in the case of the reagent, can also be applied to the reagent remaining amount registration.

Example 3
Next, Embodiment 3 of the present invention will be described. In the third embodiment, the schematic configuration of the automatic analyzer, the schematic configuration of the dispensing mechanism 105, the configuration of the reagent containers 203 and 204, and the schematic functional block of the control unit 115 are the same as those of the first embodiment. Detailed description will be omitted.

  The third embodiment of the present invention is an example of improving the accuracy of determining whether or not the liquid level detection can be used for the container 204 with the lid in the first and second embodiments.

  First, the following α, β, γ (threshold C), and δ are defined as signals related to liquid level detection. The units of α, β, γ, and δ are voltages.

α: Capacitance change amount at the height of the container lid β: Capacitance change amount due to ambient influence when descending from the container lid to the liquid level γ: Threshold (C)
δ: Amount of change in capacitance at the minimum amount of liquid In the case of the structure in which the liquid easily adheres to the lid of the reagent container and the situation where the capacitance of the attached liquid is large frequently occurs, Since the determination is α + β> γ, there are frequent cases of abnormal (NG). In other words, in the first embodiment, the liquid level signal at which the nozzle 201 stops in step S2 of FIG. 7 is determined based on whether or not the electrostatic capacitance has reached the threshold value γ, but before the nozzle 201 reaches the liquid level. In some cases, the position may be larger than the threshold value γ, and in the subsequent confirmation of the capacitance value, it is considered that there are frequent cases where the value becomes less than γ due to the disappearance of bubbles or the like and is determined to be abnormal.

  In order to avoid the above case, it is conceivable to change the threshold value γ according to the capacitance change amount. Hereinafter, this operation will be described.

  In the case of a container with a lid, the lowering operation is performed in two steps, and is temporarily lowered to a height at which the penetration of the lid by the nozzle 201 is completed, and then lowered to the suction position. At this time, by generating a threshold value in the circuit with reference to the capacitance value at the position after the first descending operation is completed, the capacitance α composed of the liquid adhering to the lid is also taken into account. A threshold is generated in the state. For example, a value obtained by adding a predetermined capacitance value to the capacitance value at the position after the first descending operation is completed is set and stored as a threshold value.

  At this time, the descending capacitance is monitored not only by the threshold value but also by comparison with the capacitance at the reference position (position after the first descending operation is completed). This is for monitoring whether or not the contact between the liquid adhering to the lid and the nozzle is released during the second descent and determining the appropriateness of the threshold value.

  As a configuration for realizing this operation, a position sensor is also arranged at the height of the lid, and a threshold value is generated when the sensor is removed, or a threshold value is generated when the second operation is started. For example, a timing signal may be issued.

  Further, as another means, a means for storing both the height of the nozzle 201 and the voltage conversion value of the capacitance and performing control by calculating α, β, γ, and δ is also conceivable.

  When the change in capacitance is converted to a voltage of 0 to 5 V, and the voltage increases as the capacitance increases, the relationship of 5 V> γ + α is established, and the nozzle 201 is positioned more than the lid position. When is lowered, a process of adding α to the threshold γ is performed. In this case, since the total amount of change when the liquid level in the reagent container is touched is approximately γ + δ, when the liquid level in the reagent container is touched, γ + α <α + δ is satisfied and the liquid level can be detected. it can.

  In the operation flowchart when the third embodiment is applied to the first embodiment, step S2 in FIG. 7 is replaced with the following operation.

  That is, in step S2, it is lowered once to a height at which the penetration of the lid by the nozzle 201 is completed and stopped, the capacitance value at that time is stored in the memory 115b, and the operation command unit 115f is stored in the memory 115b. A predetermined capacitance value is added to the capacitance value and stored in the memory 115b as a threshold value γ. Thereafter, the nozzle vertical drive mechanism 118 starts a second lowering operation in response to a command from the operation command unit 115f, When the capacitance value reaches the threshold value γ stored in the memory 115b, the lowering operation of the nozzle 201 is stopped.

  In the operation flowchart when the third embodiment is applied to the second embodiment, steps 10a and S20 in FIG. 10 are replaced with the following operations.

  That is, in step S10a, it is lowered once to a height at which the penetration of the lid by the nozzle 201 is completed and stopped, the capacitance value at that time is stored in the memory 115b, and the operation command unit 115f is stored in the memory 115b. A predetermined capacitance value is added to the capacitance value and stored in the memory 115b as a threshold value γ. Thereafter, the nozzle up / down driving mechanism 118 starts a second lowering operation (lowering) according to a command from the operation command unit 115f. When the electrostatic capacity value reaches the threshold value γ stored in the memory 115b, the lowering operation of the nozzle 201 is stopped in step S20.

  According to the third embodiment described above, the same effect as that of the first embodiment can be obtained, and the threshold value is exceeded when the liquid surface of the reagent main body is touched without being affected by the liquid attached to the lid, so It becomes possible to detect the liquid level.

  In the method of changing the threshold value, there is a restriction that the signal change amount is suppressed within the power supply voltage of the circuit. For this, a method of changing sensitivity instead of threshold is effective. In this case, the relationship with circuit noise is a limitation. Whether to change the threshold value or sensitivity is selected according to the circuit environment.

  On the other hand, structural ingenuity for increasing the case of success determination of the present invention is also conceivable. In the present invention, as described above, for example, the inner part of the lid has a cone shape protruding downward, and the container material is made of a material having water repellency and insulation such as polypropylene, so that the attached liquid is liquid. It is considered that the structure is easily separated from the reagent on the inner wall without remaining as a film, and the inside of the lid shown in FIG.

  The above-described example is an example in which the present invention is applied to a reagent dispensing operation, but can also be applied to an operation of dispensing a sample (specimen) into a reaction container.

  In addition, reagents and samples are collectively defined as liquid, both reagent containers and sample containers are liquid containers, both reagent dispensing mechanisms and sample dispensing mechanisms are liquid dispensing mechanisms, reagent dispensing nozzles and sample dispensing. Both nozzles are collectively referred to as liquid dispensing nozzles.

  DESCRIPTION OF SYMBOLS 100 ... Reaction disk (reaction mechanism), 101 ... Conveyance line, 102 ... Rotor, 103 ... Reagent disk, 104 ... Reaction tank, 105 ... Dispensing mechanism, 106 ... Stirring mechanism, 107 ... Spectroscope, 108 ... Reaction container cleaning mechanism, 109 ... Nozzle cleaning mechanism, 110 ... Sample container, 111 ... Sample rack, 112 ... Reaction container, 113 ..Reagent container, 115 ... Control unit, 115a ... Liquid level detection unit, 115b ... Memory, 115c ... Pressure judgment unit, 115d ... Normal / abnormal judgment unit, 115e ... Nozzle position Judgment unit, 115f ... operation command unit, 116, 201 ... nozzle, 117 ... electrostatic capacity detection mechanism, 118 ... nozzle up / down drive mechanism, 119 ... display unit, 120 ... suction Discharge drive mechanism, 2 2 ... pressure sensor, 203 ... reagent container without lid, 204 ... reagent container with lid, 204a ... lid, 205 ... reagent body, 206 ... inside of the lid is not wet 207 ... Reagent container in a state where the inside of the lid is wet and is in conduction with the reagent body

Claims (8)

A reaction mechanism in which a reaction vessel is disposed;
A spectroscope for analyzing a sample in a reaction vessel disposed in the reaction mechanism;
A liquid dispensing nozzle that sucks a liquid from a liquid container containing a reagent or sample liquid and discharges it to the reaction container disposed in the reaction mechanism, and a capacitance for detecting the capacitance value of the liquid dispensing nozzle A liquid dispensing mechanism having a detection mechanism and a pressure sensor for detecting the pressure in the liquid dispensing nozzle;
A control unit for controlling the operation of the reaction mechanism, the spectroscope, and the liquid dispensing mechanism;
The control unit includes
A nozzle position determination unit for determining the position of the liquid dispensing nozzle;
A pressure determination unit for determining a pressure value from the pressure sensor;
A liquid level detection unit that detects the liquid level of the liquid from the capacitance detected by the capacitance detection mechanism;
A normal / abnormality determination unit that determines whether the operation of the liquid dispensing mechanism is normal or abnormal based on the determination of the nozzle position determination unit, the pressure determination unit, and the liquid level detection unit;
An automatic analyzer having an operation command unit that commands the operation of the liquid dispensing mechanism based on the determination of the normal / abnormal determination unit. The automatic analyzer according to claim 1,
The liquid dispensing mechanism has a nozzle vertical drive mechanism that drives the dispensing nozzle in the vertical direction,
The operation command unit commands the nozzle up / down drive mechanism to move the liquid dispensing nozzle of the liquid dispensing mechanism downward toward the liquid level in the liquid container, and the liquid level detection unit controls the liquid level. When detected, the lowering operation of the nozzle by the nozzle vertical drive mechanism is stopped, and the normal / abnormal determination unit determines whether or not the stop position is normal. When the stop position is determined normal, the liquid dispensing is performed. The liquid suction operation by the nozzle is started, and after the liquid suction operation is finished, the pressure value determined by the pressure determination unit is normal and the liquid level detection unit detects that the liquid level is detected. When the unit determines, the automatic analyzer is configured to instruct the liquid dispensing nozzle to move upward by the nozzle vertical drive mechanism. The automatic analyzer according to claim 2,
The control unit has a memory,
The operation command unit instructs the nozzle vertical drive mechanism to move the liquid dispensing nozzle of the liquid dispensing mechanism downward toward the liquid level in the liquid container, and the nozzle position determination unit Is lowered to the height of the liquid container, the descent operation of the liquid dispensing nozzle is stopped, and the capacitance value detected by the capacitance detection mechanism and a predetermined capacitance value are added. Then, the liquid level is stored in the memory as a threshold value, the descent operation of the liquid dispensing nozzle is restarted, and when the detected electrostatic capacitance reaches the threshold value, the liquid level detection unit An automatic analyzer characterized by determining that a surface has been detected. The automatic analyzer according to claim 1,
The liquid container has a lid, and an inner portion of the lid has a cone shape projecting to the inner lower side of the liquid container, and the material of the liquid container is a polypropylene material having high water repellency and insulating properties. An automatic analyzer characterized by that. The automatic analyzer according to claim 1,
The control unit has a memory,
The liquid dispensing mechanism has a nozzle vertical drive mechanism for driving the liquid dispensing nozzle in the vertical direction,
The operation command unit commands the nozzle up / down drive mechanism to move the liquid dispensing nozzle of the liquid dispensing mechanism downward toward the liquid level in the liquid container, and the liquid level detection unit controls the liquid level. Upon detection, the liquid dispensing nozzle descending operation by the nozzle up-and-down drive mechanism is stopped, the normal / abnormal determination unit determines whether the stop position is normal, and if the stop position is determined normal, When the liquid level is detected by the liquid level detection unit and the liquid level is detected, the liquid dispensing nozzle is moved upward by the nozzle vertical drive mechanism, and the liquid content determined by the nozzle position determination unit is detected. An automatic analyzer characterized by calculating a nozzle lowering amount based on a stop position of the injection nozzle, obtaining a liquid level height in the liquid container, and registering a remaining liquid amount in the memory. The automatic analyzer according to claim 5,
The operation command unit instructs the nozzle vertical drive mechanism to move the liquid dispensing nozzle downward toward the liquid level in the liquid container, and then the nozzle position determination unit detects that the liquid dispensing nozzle If it is determined that the liquid container has been lowered to the height, the liquid dispensing nozzle is stopped, and the capacitance value detected by the capacitance detection mechanism is added to a predetermined capacitance value. , And stored in the memory as a threshold value, the descent operation of the liquid dispensing nozzle is restarted, and when the detected electrostatic capacity reaches the threshold value, the liquid level detection unit detects the liquid level. An automatic analyzer characterized by determining that it has been detected. In the liquid dispensing method in the automatic analyzer,
The liquid dispensing nozzle that sucks and discharges the liquid that is the reagent or the sample is moved downward toward the liquid container containing the liquid,
While determining the position of the liquid dispensing nozzle by a nozzle position determination unit, detecting the capacitance value of the liquid dispensing nozzle,
When it is determined that the liquid dispensing nozzle has reached the liquid level based on the detected capacitance value, the lowering operation of the liquid dispensing nozzle is stopped,
When the position of the liquid dispensing nozzle is the height of the liquid container and the detected capacitance value does not indicate that the liquid dispensing nozzle has reached the liquid level, The liquid in the liquid container is sucked by the liquid dispensing nozzle,
While detecting the capacitance value of the liquid dispensing nozzle, detecting the pressure in the liquid dispensing nozzle,
The detected capacitance value of the liquid dispensing nozzle indicates that the liquid dispensing nozzle is in contact with the liquid surface of the liquid, and the detected pressure in the liquid dispensing nozzle is the liquid A liquid dispensing method in an automatic analyzer, wherein the liquid dispensing nozzle is moved upward when the dispensing nozzle is in contact with the liquid surface of the liquid. In the liquid dispensing method in the automatic analyzer,
The liquid dispensing nozzle that sucks and discharges the liquid that is the reagent or the sample is moved downward toward the liquid container containing the liquid,
While determining the position of the liquid dispensing nozzle by a nozzle position determination unit, detecting the capacitance value of the liquid dispensing nozzle,
When it is determined that the liquid dispensing nozzle has reached the liquid level based on the detected capacitance value, the lowering operation of the liquid dispensing nozzle is stopped,
Comparing the position where the liquid dispensing nozzle descending operation is stopped with the position of the liquid dispensing nozzle determined by the nozzle position determination unit, is the stopped position below the height of the liquid container? Determine whether or not
When it is determined that the stopped position is below the height of the liquid container, the capacitance value of the liquid dispensing nozzle is detected, and based on the detected capacitance value, the liquid dispensing nozzle When it is determined that the liquid level has been reached, the liquid dispensing nozzle is moved upward by the nozzle vertical drive mechanism, and the nozzle lowering amount is determined based on the nozzle position determined by the nozzle position determination unit. The liquid dispensing method in the automatic analyzer is characterized in that the liquid level height in the liquid container is calculated and the remaining amount of liquid is registered in a memory.

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