Automatic analysis device

Abstract

In order to provide an automatic analysis device that, without reducing throughput, is capable of determining whether an abnormality does not occur in a dispensing mechanism and a specimen can be discharged at the bottom of a reaction container as expected, the automatic analysis device has the following structure.　The automatic analysis device comprises: a control unit that performs control so as to cause an arm vertical movement mechanism to lower a dispensing probe until the dispensing probe comes into contact with an object below, and to cause the arm vertical movement mechanism to move the dispensing probe upward after a detector detects the deviation of the dispensing probe from the normal position; and a determination unit that determines the presence or absence of an abnormality in the dispensing mechanism, on the basis of a first timing at which the detector no longer detects the deviation of the dispensing probe due to the downward movement of the dispensing probe by an elastic body.

Description

Automatic analyzer

[0001] The present invention relates to an automatic analyzer.

[0002] In an automatic analyzer that uses a liquid sample such as blood as a specimen, the specimen to be measured is discharged from the tip of a probe and adhered to the bottom of a reaction vessel. At this time, as a method of discharging the specimen in a state where the tip of the probe surely contacts the bottom surface regardless of the bottom surface height of the reaction vessel, the following technique described in Patent Document 1 is known. The arm is lowered to the reaction vessel, the probe is elastically contacted, and the lowering operation is stopped by a detector that detects the stop position. Then, the bottom surface height of the reaction vessel is corrected by raising the arm by the movement distance stored in the memory in advance.

[0003] Japanese Patent Application Laid-Open No. 2013-068540 International Publication No. 2018 / 055929

[0004] In an automatic analyzer, the specimen used for measurement is discharged from the tip of a specimen probe and adhered to the bottom of a washed reaction vessel. This can suppress the contamination of contaminants (such as reagents) inside the specimen probe, and can suppress the consumption of the specimen and reduce the washing time.

[0005] The specimen discharged from the tip of the probe usually falls to the bottom of the reaction vessel by gravity. On the other hand, when the discharge amount is small, the specimen may be pulled up to the outer wall of the probe against gravity. If the probe rises from the reaction vessel as it is, the specimen will not adhere to the bottom of the reaction vessel. This phenomenon is called the specimen carry-back phenomenon. When the specimen carry-back phenomenon occurs, the chemical reaction does not proceed, so the measurement result may be abnormal.

[0006] When a very small amount of specimen is discharged in a state where the tip of the probe does not contact the bottom of the reaction vessel, the specimen carry-back phenomenon is likely to occur. Since the bottom surface height of the reaction vessel is slightly different for each reaction vessel, in Patent Document 1, when the arm is lowered to the reaction vessel, the probe having a stop position detection mechanism is elastically contacted with the bottom of the reaction vessel, and the stop position detection mechanism is detected by a stop position detector to stop the lowering operation. Then, the bottom surface height of the reaction vessel is corrected by raising the arm by the movement distance stored in the memory in advance, and the specimen is discharged in a state where the probe contacts the bottom of the reaction vessel.

[0007] Furthermore, Patent Document 2 describes that, in the upward movement after elastically contacting the probe with the reaction vessel, the probe is made to rise by a distance pre-stored in memory after the upward movement has been performed until the stop position detection mechanism no longer detects it, thereby correcting the vertical height of the probe and ensuring that the sample is dispensed with the probe in contact with the bottom of the reaction vessel more reliably.

[0008] These controls assume that the probe moves in the opposite direction to the upward movement of the arm due to an elastic member such as a spring (i.e., as the arm rises, the probe is pushed downward by the elastic member). If the probe follows the upward movement of the arm (i.e., the probe does not push downward but rises together with the arm), there is a possibility that the sample will be discharged with the probe separated from the bottom of the reaction vessel. For example, if fine dust adheres to the probe, the vertical sliding properties of the probe will deteriorate, increasing resistance to the elastic member. As a result, the probe will not move in the opposite direction to the upward movement of the arm, and the sample may be discharged with the probe separated from the bottom of the reaction vessel, potentially resulting in the sample being taken back.

[0009] Given the above background, there was a need for a simple and real-time method to determine whether there was any abnormality in the dispensing mechanism, whether the vertical sliding of the probe was functioning as expected, and whether the sample could be dispensed under those conditions.

[0010] The objective of the present invention is to provide an automated analyzer that can determine, without reducing throughput, whether there is any abnormality in the dispensing mechanism and whether the sample is being dispensed from the bottom of the reaction vessel as expected.

[0011] The present invention, in order to achieve the above objective, has the following configuration: an automatic analyzer comprising: a dispensing mechanism having a dispensing probe for aspirating and dispensing liquid; an arm for holding the dispensing probe; an elastic body provided on the arm for pressing the dispensing probe downward; an arm vertical movement mechanism for moving the arm up and down; and a detector for detecting when the holding position of the dispensing probe relative to the arm deviates from its normal position; a control unit that controls the arm vertical movement mechanism to lower the dispensing probe until it contacts an object below, and after the detector detects that the dispensing probe has deviated from its normal position, to move the dispensing probe upward using the arm vertical movement mechanism; and a determination unit that determines whether or not there is an abnormality in the dispensing mechanism based on a first timing at which the detector no longer detects the displacement of the dispensing probe due to the elastic body moving the dispensing probe downward.

[0012] The automatic analyzer also comprises a dispensing mechanism having a dispensing probe for aspirating and dispensing liquid, an arm for holding the dispensing probe, an arm vertical movement mechanism for moving the arm up and down, and a detector for detecting when the holding position of the dispensing probe relative to the arm deviates from its normal position; a control unit that controls the arm vertical movement mechanism to lower the dispensing probe until it touches the reaction vessel; and a determination unit that determines the fixing status of the reaction vessel based on a second timing until the detector detects that the dispensing probe has deviated from its normal position.

[0013] According to the present invention, it is possible to provide an automated analyzer that can determine whether there is no abnormality in the dispensing mechanism and whether the sample is being dispensed from the bottom of the reaction vessel as expected, without reducing throughput.

[0014] Schematic diagram of the automated analyzer Schematic diagram of the sample dispensing mechanism Diagram showing an example of the sample section and detector Diagram comparing the behavior when there is a sliding abnormality in the dispensing operation Diagram explaining probe release distance X1 and probe descent distance X2 Diagram explaining the variation in probe release distance when there is a probe sliding abnormality Flowchart for abnormality detection Diagram explaining probe release distance and probe descent distance when the reaction vessel is not sufficiently fixed Diagram explaining probe release distance and probe descent distance when the arm cover is not sufficiently fixed Diagram explaining the dispensing confirmation operation after probe replacement Diagram explaining the probe release distance result confirmation screen

[0015] The embodiments of the present invention will be described below with reference to the drawings.

[0016] An automated analyzer to which the present invention is applied will be described with reference to Figure 1. The automated analyzer consists of a sample inlet 101, a transport line 102, sample dispensing mechanisms 103 and 104, a reaction disk 105, a reaction vessel 106 arranged around its circumference, reagent dispensing mechanisms 107, 108, 109, and 110, a reagent disk 112 on which reagent containers 111 containing reagents are arranged around its circumference, a stirring mechanism 113, a photometric mechanism 114, sample probe washing mechanisms 115 and 116, reagent probe washing mechanisms 117, 118, 119, and 120, a reaction vessel washing mechanism 121, and an ultrasonic cleaning mechanism 122. The photometric mechanism includes a light source 123 and a detector 124.

[0017] The sample probe washing mechanism and the reagent probe washing mechanism are installed on the operating trajectories of the sample dispensing mechanisms 103 and 104 and the reagent dispensing mechanisms 107, 108, 109, and 110, respectively. Each mechanism is equipped with a member 125 (also referred to as a "detection member") that detects the operating state of the mechanism. The automated analyzer also includes an input unit 126 for the user to input measurement items and measurement conditions using a keyboard or voice, a signal processing unit 127 that processes input and output data signals, and an output unit 128 that displays information related to the automated analyzer, such as operation details and analysis results, using a graphical user interface (GUI).

[0018] The signal processing unit consists of a control unit 129 that controls the operation of the device according to the input, a calculation unit 130 consisting of a computer that performs calculations on photometric data and signals obtained by the photometric mechanism, a storage unit 131 that stores the calculated data, and a determination unit 132 that performs threshold discrimination and the like. These determination units may be implemented using a dedicated circuit board, but generally the program programmed into the calculation unit 130, which consists of a computer, corresponds to the "determination unit".

[0019] Analysis using an automated analyzer is mainly carried out as follows: The operator places a sample rack 134, which can hold multiple sample containers (such as blood collection tubes) 133 containing samples such as blood to be used for analysis, into the sample loading port 101. When the operator inputs the measurement details into the input unit 126 and starts the measurement (operation), analysis information and operation instructions based on the input measurement details (measurement items) are sent to the control unit 129. After the device performs analysis preparation operations such as cleaning the reaction cell and checking for abnormalities in the mechanism, the analysis operation starts, and the sample rack 134 stored in the sample loading port 101 is automatically transported to the transport line 102.

[0020] The sample rack 134, which has been transferred to the transport line 102, is moved to the sample aspiration position (not shown) by a rotating belt provided on the transport line 102. When the sample rack 134 has been moved to the sample aspiration position, the motor of the drive unit of the sample dispensing mechanism 103 rotates at the instruction of the control unit 129, and the sample probe of the sample dispensing mechanism 103 moves from the sample probe washing mechanism 115 to the sample aspiration position. Once the sample dispensing mechanism 103 has moved to the sample aspiration position, it starts the downward movement of the sample probe. When the liquid level detection sensor (not shown), which is one of the sensors constituting member 125, detects that the tip of the sample probe has come into contact with the sample in the sample container that has been transferred in advance, the control unit 129 stops the motor of the drive unit of the sample dispensing mechanism 103, and the downward movement of the sample probe stops.

[0021] After the sample and the sample probe come into contact, the control unit 129 controls the sample dispensing mechanism 103 to aspirate the amount of sample required for analysis and to move vertically upward while holding the aspirated sample in the sample probe. Subsequently, the control unit 129 controls the sample probe of the sample dispensing mechanism 103 to move above the reaction vessel 106, then to lower the sample probe to the bottom of the reaction vessel 106, and finally to dispense the sample held in the sample probe.

[0022] After the sample is dispensed into the reaction vessel, the control unit 129 raises the sample probe of the sample dispensing mechanism 103 vertically, then rotates the sample probe in an arc to move it to the sample probe washing mechanism 115, where the sample probe is washed, thus completing the series of sample dispensing operations. The reaction vessel 106 containing the sample is moved to the reagent dispensing position (not shown) by the rotation of the reaction disk 105. The reagent dispensing mechanisms 107 and 109 draw reagents corresponding to the items used in the analysis from the reagent container 111 and dispense the reagents into the reaction vessel 106 containing the sample. After the reagents are dispensed into the reaction vessel 106, the reagent probes of the reagent dispensing mechanisms 108 and 110 are moved to the reagent probe washing mechanisms 117 and 119 by the rotation of the motor, where the reagent probes are washed, thus completing the series of reagent dispensing operations.

[0023] Furthermore, when performing the reagent dispensing operation, a liquid level detection sensor detects when the reagent probe comes into contact with the liquid surface inside the reagent container, thereby confirming whether there is any abnormality in the amount of reagent inside the reagent container. In addition, the dispensing mechanism (the "sample dispensing mechanism" and the "reagent dispensing mechanism" are collectively referred to as the "dispensing mechanism"; the same applies hereinafter) has a pressure sensor that monitors the pressure in the flow path to determine whether the dispensing operation was performed correctly. In the automated analyzer shown in Figure 1, the sample dispensing and reagent dispensing operations are performed by two pairs of sample dispensing mechanisms 103, 104 and reagent dispensing mechanisms 108, 110, and the processing capacity is improved by controlling them to perform the dispensing operations alternately with staggered cycles.

[0024] Through the above operations, the reaction solution consisting of the sample and reagent dispensed into the reaction vessel is stirred by the stirring mechanism 113, causing the sample and reagent to react and changing optical properties such as absorbance. The optical properties of the reaction solution are measured by detecting the light originating from the light source 123 with the detector 124 as the reaction vessel 106 passes through the photometric mechanism 114 as the reaction disk 105 rotates. The obtained data is sent to a computer, which uses the calculation unit 130 to calculate the concentration of the analytical items contained in the sample and outputs the result to the output unit 128. Depending on the user's instructions, the output unit 128 can also output detailed information such as the reaction time course and dispensing time.

[0025] The reaction vessel 106 and the probes of each dispensing mechanism used are washed with a washing solution by the reaction vessel washing mechanism 121 and the sample probe washing mechanisms 115, 116, and 117, 118, 119, and 120, thereby maintaining analytical performance and being reused for subsequent analyses. If necessary, washing is also performed by the ultrasonic washing mechanism 122.

[0026] At the start of the analysis process described above, preparatory actions are performed. These include resetting the mechanism position, cleaning the reaction vessel, and obtaining blank values, all to ensure that subsequent analyses can be carried out without interruption.

[0027] Figure 2 shows a sample dispensing mechanism in one embodiment of the present invention. The sample dispensing mechanism 103 includes a sample probe 201 for aspirating and dispensing a sample, an arm 202 for holding the sample probe 201, an elastic body 203 for elastically supporting the sample probe 201, an arm cover 204 for holding the elastic body 203 and provided adjacent to the upper part of the arm 202, which presses the sample probe 201 in the direction of gravity (downward), a capacitance detector (not shown; used as a liquid level detection sensor; the capacitance detector may be stored inside the arm 202 depending on the device space) for detecting changes in the capacitance of the sample probe 201, a detection part 205 fixed to the sample probe 201, a detector 206 installed on the arm 202 for detecting the movement of a detection plate 210 provided on the detection part 205, an arm vertical movement mechanism 207 for moving the arm 202 up and down, and a rotation mechanism 208 for rotating the arm 202.

[0028] When the sample probe 201 is in its normal holding position (also referred to as the "normal position"), the detection plate 210 is not in the detection position of the detector 206, which consists of a photointerrupter or the like, so the detector 206 does not emit a detection signal. When the tip of the sample probe 201 comes into contact with an obstacle while it is descending, the elastic body 203 contracts, the detection plate 210 of the detection part 205 moves upward, blocking the optical path of the photointerrupter, and the detector 206 emits a detection signal. In this way, the detector 206 has the function of indicating that the sample probe 201 is at a position where its descent should stop when its tip comes into contact with an obstacle, and is therefore sometimes referred to as a "stop position detection" or "obstacle detection unit".

[0029] Figure 3 will be used to illustrate the details of the configuration examples of the detection unit 205 and the detector 206. Figure 3(a) shows an example in which the detection unit 205 has a detection plate 210 in the center (to the right in the side view), and shows a state in which the tip of the sample probe 201 has come into contact with some obstacle and the sample probe 201 has risen (retracted). When the tip of the sample probe 201 hits some object, such as the bottom surface of the reaction vessel or the top panel of the analyzer, while the arm 202 is descending, the sample probe 201 is configured to move upward relative to the position of the arm 202 (in other words, the sample probe 201 retracts into the arm 202) as the elastic body 203 (a coil spring in the example of Figure 3) compresses, thereby suppressing deformation of the sample probe 201 and damage to the bottom surface of the reaction vessel or the top panel of the analyzer. Since the detection part 205 is fixed to the sample probe 201, when the sample probe 201 moves upward relative to the position of the arm 202, the detection plate 210 moves upward along with the sample probe 201.

[0030] When the sample probe 201 is in its normal position, as shown in Figure 2, the detection plate 210 does not block the light from the LED light source 211, and the photodetector, such as a photodiode, in the detector 206 detects the light. When the sample probe 201 is moved upward, the detection plate 210 moves upward, blocking the light from the LED light source 211, and the photodetector in the detector 206 stops detecting the light. This makes it possible to detect that the tip of the sample probe 201 has come into contact with some object, such as the bottom of the reaction vessel or the top panel of the analyzer (the detector 206 consists of a so-called "photointerrupter").

[0031] Figure 3(b) shows an example in which the detection area 205 is a light-transmitting hole, an LED light source 211 such as an LED is placed opposite the hole, and the detector 206 is a light detector. Since the sample probe 201 is made of a hollow pipe, a light-transmitting through-hole 212 is provided in the hollow pipe. When the sample probe 201 is moved upward from its normal position, the light from the LED light source 211 passes through the through-hole 212 and is detected by the detector 206 equipped with a light receiver (photodiode, etc.). This makes it possible to detect when the sample probe 201 has come into contact with some kind of obstacle. When the arm 202 rises and the sample probe 201 rises, the elastic body 203 stretches, causing the through-hole 212 to shift downward, and the light from the LED light source 211 no longer passes through the through-hole 212, so the detector 206 can no longer detect the light. This can be used to detect whether the sample probe 201 has shifted upward or is in its normal position. In addition to the light-based detector described above, the detection of the detection area 205 moving away from the detector 206 may also be performed using an electrical switch such as a microswitch.

[0032] Figure 4 shows the details of sample discharge. When the sample probe 201 is lowered to the bottom of the reaction vessel 106, the detector 206 detects whether the sample probe 201 has come into contact with the bottom of the reaction vessel 106. When the detector 206 detects that the sample probe 201 has come into contact with the bottom of the reaction vessel 106, the control unit 129 in Figure 1 stops the descent of the sample probe 201. In this embodiment, considering the effects of vibrations and other factors associated with contact with the bottom of the reaction vessel, after the detector 206 makes the detection, the probe is lowered by a preset excess amount before being stopped.

[0033] After the sample probe 201 has finished descending, the sample held within the sample probe 201 is dispensed. If the sample probe 201 is excessively pressed against the bottom of the reaction vessel 106 during sample dispensing, the sample may not be dispensed properly due to the bending of the sample probe 201 or the deflection of the reaction vessel 106. Therefore, an upward movement is performed to correct the bending of the sample probe 201 and the deflection of the reaction vessel 106, and to ensure that the sample is dispensed reliably from the bottom of the reaction vessel 106.

[0034] During the upward movement after elastically bringing the sample probe 201 into contact with the reaction vessel 106, the sample dispensing mechanism is moved upward until the detection plate 210 of the detection area 205 reaches a position where it does not obstruct the light from the detector 206 (sometimes referred to as "the detection plate detaching from the detector"). After that, it is moved upward by a distance pre-stored in memory to correct the vertical height of the sample probe 201 relative to the detector 206, enabling the sample to be dispensed with the sample probe 201 in contact with the bottom of the reaction vessel 106 more reliably.

[0035] The automated analyzer of this embodiment is characterized by comprising: an arm vertical movement mechanism 207 that lowers the dispensing probe (sample probe 201 in this example) until it contacts an object below (such as the reaction vessel 106 or a probe testing position provided on the top panel of the analyzer); a detector 206 that detects that the dispensing probe has shifted from its normal position (is not in its normal position), then the arm vertical movement mechanism 207 moves the dispensing probe upward, and a determination unit that determines whether or not there is an abnormality in the dispensing mechanism based on a first timing at which the detector no longer detects the displacement of the dispensing probe.

[0036] "Based on the first timing" means that it is based on the time from when the detector 206 detects that the dispensing probe has shifted from its normal position (is not in its normal position), until the time from when the arm vertical movement mechanism 207 moves the dispensing probe upward until the detector no longer detects that the dispensing probe has shifted (time required for detachment), or the distance the dispensing probe has moved upward from when the detector 206 detects that the dispensing probe has shifted from its normal position (is not in its normal position) until the first timing occurs (the number of steps required for the stepping motor that moves the arm vertical movement mechanism to raise the arm, which is also called the "(dispensing) probe detachment distance").

[0037] The system stores the distance (or time taken for the sample probe to detach) during this dispensing operation and compares it to a preset reference value to determine whether there is any abnormality in the dispensing mechanism and whether the sample is being dispensed to the bottom of the reaction vessel as expected.

[0038] As an example of the first timing, the method for calculating the "probe detachment distance" will be explained using Figure 5. First, the sample probe 201 is lowered (Figure 5(a)). After the detection part 205 enters the detector 206 (after the detection plate 210 of the detection part 205 enters a position that blocks the light of the detector 206), the excess movement amount is operated and the position where the sample probe 201 stops is set as the reference position (Figure 5(b)). In the subsequent upward movement of the sample probe 201 accompanying discharge, the distance traveled until the detection plate 210 of the detection part 205 reaches a position that does not block the light of the detector 206 (sometimes referred to as "the detection plate detaching from the detector") (the distance the sample probe 201 rises from the reference position until the detection plate detaches) is stored in the storage unit 131 as the probe detachment distance (X1) (Figure 5(c)). The time required for probe withdrawal (probe withdrawal time) is, as the name suggests, "the time required for withdrawal," and its meaning is clear, so no explanation will be provided.

[0039] Furthermore, the meaning of "based on the second timing" until the arm 202 descends from the upper limit point to the reference position is defined, similarly to "based on the first timing," as the time required for the arm 202 to descend from the upper limit point to the reference position, or the distance the dispensing probe moved (probe descent distance (X2)) until the arm 202 descends from the upper limit point to the reference position by the second timing, which is the time required for the arm 202 to descend from the upper limit point to the reference position. The second timing is also recorded in the storage unit 131, similar to the first timing.

[0040] The probe detachment distance (X1) does not fundamentally change in the same device unless the sample probe 201 is replaced. Therefore, the state of the dispensing mechanism can be determined by monitoring the variation in the probe detachment distance.

[0041] For example, Figure 6 illustrates a method for determining the state of the dispensing mechanism by comparing the probe detachment distance with a pre-set reference value. When fine debris adheres to the sample probe 201 and its sliding properties deteriorate, the resistance to the elastic body increases, causing the probe detachment distance to be larger than normal. As a result, outliers (abnormal values) occur abruptly relative to the reference value. Figure 6 shows the result when the probe detachment distance (vertical axis, which indicates the distance based on the number of step pulses of the stepping motor that moves the sample probe up and down) is plotted against the number of measurements (horizontal axis). Each plot corresponds to the probe detachment distance during one sample dispensing. As mentioned above, the variation in probe detachment distance is usually very small, so by appropriately setting a threshold for distinguishing between the reference value and abnormal values, it is possible to determine dispensing abnormalities caused by deteriorated sliding properties.

[0042] Figure 7 shows a flowchart for anomaly detection. When the analysis operation is started (S1), the device sets a criterion for determining the sliding properties of the sample probe 201 (S2), and the control unit 129 performs the dispensing operation (S3). The probe detachment distance during the dispensing operation is acquired and recorded (S4). In this case, for a more detailed analysis, a statistical distance may be calculated from the obtained data. Next, a threshold determination is performed on the probe detachment distance (S5), and if an outlier occurs, an alarm is output to notify that a dispensing abnormality has occurred.

[0043] Multiple thresholds may be used depending on the degree of the outlier. For example, a threshold 2 may be set that is greater than threshold 1, and subsequent actions may be changed based on thresholds 1 and 2 (S6). For threshold 1, it is considered a minor dispensing abnormality and only an alarm is output (S7), and the analysis continues (S8). If it is greater than threshold 2, it is determined that there is a high possibility of dispensing into the air, and in addition to outputting an alarm (S9), the test item may be treated as a measured value with an alarm, and measures such as retesting may be taken (S10).

[0044] The above flow is an example and can be arbitrarily set according to the device configuration and processing speed. For example, the number of times exceeding threshold 1 is counted, and when the cumulative number exceeds a specific value, it may be determined that the abnormality caused by hardware is deteriorating, and the user may be prompted to replace or clean the sample probe. Thereby, the user can perform maintenance of sample probe replacement according to the actual usage situation. Further, when there are multiple sample probes, the sample probe for which the threshold determination has become abnormal may be masked so as not to be used in measurement, and the sample probe for which the threshold determination is normal may be controlled to be used in analysis. Thereby, it is possible to suppress the influence on throughput.

[0045] For the purpose of performing a more stable dispensing operation, the increase amount of the subsequent sample dispensing operation may be corrected using the probe detachment distance used in the determination. For example, when wear powder is generated due to the sample probe 201 rubbing against the arm 202 and the sliding property is gradually deteriorating, there may be a deviation between the increase amount stored in the memory in advance and the actually required increase amount. Therefore, by correcting the increase amount using the probe detachment distance, it is controlled to surely discharge the sample at the bottom of the reaction vessel 106. By performing the probe detachment distance used in the above correction in the analysis preparation operation and correcting the increase amount in the analysis operation based on that value, analysis can be performed without affecting the processing speed.

[0046] Regarding the threshold determination method, in addition to setting the threshold using a reference value, comparison with the probe detachment distance during the previous dispensing operation for the same reaction vessel and comparison with the probe detachment distance during the immediately previous dispensing operation may be performed. As a method for setting the reference value, it may be set in advance based on experimental data, or the acquisition of the reference value may be performed in the analysis preparation operation. During the analysis preparation operation, only the lowering and raising operations are performed without sucking and discharging the sample for each reaction vessel, and by setting the reference value from the obtained plurality of probe detachment distances, it is possible to set a more accurate reference value without consuming additional consumables and without affecting the processing capacity.

[0047] Also, the above operations are repeatedly performed to obtain a plurality of probe detachment distances. By setting the reference value based on the probe detachment distance when the change over time of the obtained probe detachment distance becomes less than or equal to a predetermined change amount, it is possible to correct the variations in the dispensing mechanism after maintenance such as probe replacement and set the reference value.

[0048] Also, by paying attention not only to the probe detachment distance but also to the reference position when calculating the probe detachment distance, it is possible to determine abnormalities other than deteriorated slidability.

[0049] For example, when the reaction vessel is not sufficiently fixed, the reaction vessel sinks when it contacts the reaction vessel, so the reference position fluctuates. That is, as shown in FIG. 8(a), the aforementioned probe lowering distance X2 increases. Therefore, by setting a threshold value for the probe lowering distance, it is possible to determine that the reaction vessel has been forgotten to be fixed or that the fixing is insufficient. Since the probe lowering distance varies according to the undulation and inclination of the reaction disk that fixes the reaction vessel, the variation is small at the same location of the reaction vessel. Therefore, by setting an appropriate threshold value, it is possible to determine a poor fixation of the reaction vessel due to the operator's work leakage.

[0050] As an operation for determining a poor fixation of the reaction vessel, it is conceivable to lower the sample probe 201 with respect to each reaction vessel 106 after the analysis preparation operation or the maintenance operation of replacing the reaction vessel, record the probe lowering distance, and compare it with the threshold value to make a determination. The number of descents is obtained at least once for each reaction vessel 106, and the determination is made based on the obtained values. When an abnormality is detected, by outputting an alarm regarding the poor fixation that indicates the number and position of the detected reaction vessel, it is possible to prompt the operator to respond quickly. If the operator cannot respond, the reaction vessel can be made unusable, and the analysis can also be performed using other reaction vessels.

[0051] In addition to the above, as shown in Figure 8(b), by also performing a determination based on the probe withdrawal distance X1, it is possible to perform a more accurate determination of faulty fixing of the reaction vessel. For example, if the reaction vessel 106 sinks during descent, the detection part 205 may not fully enter the detector (stop position detector) 206, and the pulses for the descent movement may be consumed, resulting in a decrease in the probe withdrawal distance.

[0052] Therefore, by determining that the reaction vessel is not properly secured when the probe descent distance is higher than the standard and the probe detachment distance is lower than the standard, the risk of false detection can be suppressed, and the increase in extra verification work and the decrease in processing speed due to false detection can be prevented.

[0053] Another abnormality detection function that uses probe detachment distance and probe descent distance is a defect in the elastic body 203 that contacts the sample probe 201. As an example, Figure 9(a) shows the case when the arm cover 204 is loose. The elastic body 203 is attached to the arm cover 204 and is an important component for applying elastic force to the sample probe 201. If the arm cover 204 is loose due to improper attachment, the sample probe 201 will not be pressed against the arm 202, and as a result, the detection area 205 may shift upward. In this state, when the sample probe 201 comes into contact with the reaction vessel 106, the detection area 205 is more likely to enter the detector 206, so the probe descent distance X2 decreases. On the other hand, as shown in Figure 9(b), there is no change in operation after the detection area 205 enters the detector (stop position detector) 206, so the probe detachment distance X1 does not change. Using the above, it is possible to generate an alarm to notify of improper fixation of the arm cover 204.

[0054] The aforementioned issues of insufficient fixation of the reaction vessel 106 and improper fixation of the arm cover 204 often occur when replacing the reaction vessel 106 or the sample probe 201. Therefore, when replacing the reaction vessel 106 or the sample probe 201, a reaction vessel lowering operation is performed on each reaction vessel 106 to check the above items and determine if the reaction vessel 106 or arm cover 204 is improperly fixed. If improper fixation is determined in any part, an alarm for the affected part is issued to prompt the operator to take prompt action. The above check operation may be performed by the user at any time as part of maintenance, or it may be incorporated into the maintenance operation of reaction vessel replacement or sample probe replacement and performed automatically.

[0055] In particular, immediately after replacing the sample probe, the vertical sliding properties may deteriorate due to minute contamination or improper tightening of the screws, making it highly likely that the probe detachment distance will increase. Therefore, as shown in Figure 10, by performing a reaction vessel descent operation that simulates the dispensing operation until the probe detachment distance becomes constant, it is possible to perform the analysis while ensuring that the condition of the replaced sample probe is appropriate. Possible methods for determining whether the probe detachment distance has become constant include checking whether the difference between the probe detachment distance in the previous dispensing operation and the current detachment distance is below a certain value, judging by the difference from the average of the most recent multiple times, or determining whether there is an abnormality in the reagent dispensing mechanism based on the slope of the probe detachment distance. Alternatively, for example, an abnormality can be determined according to the statistical distance from a reference data group using general statistical methods such as the Mahalanobis distance.

[0056] The acquired probe detachment distance and probe descent distance are stored as logs in the memory unit, allowing service technicians to retrieve the data as needed, making debugging easier in the event of an anomaly. Furthermore, as shown in Figure 11, the ability to output trends on the device screen makes it easier to understand when changes begin to occur in the dispensing mechanism. For example, by displaying information related to the first and second measured timings (such as "time required for detachment" and "(dispensing) probe detachment distance") for each measurement day (i.e., "displayed chronologically"), it is possible to intuitively understand whether or not there is an anomaly in the dispensing probe.

[0057] Furthermore, displaying the standard deviation (SD) and the threshold for determining whether something is abnormal allows for a quantitative understanding of dispensing stability. To make it easier to identify, the number of measurements and whether or not an alarm occurred (as explained in Figure 7) for each measurement date and time may be displayed. When the displayed measurement date and time is selected with a pointing device such as a mouse, the time-series information related to the first and second measurement timings mentioned above may be displayed. In addition, the analysis results of alarm targets may be displayed in a different color. This makes it possible to understand the frequency and trend of alarm occurrences. Furthermore, if the variability in the aggregated data exceeds a pre-set threshold, the device may separately notify an alarm prompting maintenance.

[0058] In this embodiment, an automated analyzer that dispenses a sample to the bottom of the reaction vessel 106 is described. However, the present invention is effective for determining operational abnormalities or component abnormalities in a device in which the operation stop control of the sample probe 201 is performed by a detector (stop position detector) 206, and the distance until the sample probe 201 moves away from the detector (stop position detector) 206 in subsequent operation can be calculated.

[0059] 101...Sample loading port, 102...Transport line, 103, 104...Sample dispensing mechanism, 105...Reaction disk, 106...Reaction vessel, 107, 108, 109, 110...Reagent dispensing mechanism, 111...Reagent container, 112...Reagent disk, 113...Agitation mechanism, 114...Photometric mechanism, 115, 116...Sample probe washing mechanism, 117, 118, 119, 120...Reagent probe washing mechanism, 121...Reaction vessel washing mechanism, 122...Ultrasonic cleaning mechanism, 123...Light source 124...Detector, 125...Component, 126...Input unit, 127...Signal processing unit, 128...Output unit, 129...Control unit, 130...Calculation unit, 131...Storage unit, 132...Determination unit, 133...Sample container, 134...Rack, 201...Sample probe, 202...Arm, 203...Elastic body, 204...Arm cover, 205...Detection area, 206...Detector, 207...Arm up / down movement mechanism, 208...Rotation mechanism, 210...Detection plate, 211...LED light source, 212...Through hole

Claims

1. An automatic analyzer comprising: a dispensing mechanism having a dispensing probe for aspirating and dispensing liquid; an arm for holding the dispensing probe; an elastic body provided on the arm for pressing the dispensing probe downward; an arm vertical movement mechanism for moving the arm up and down; and a detector for detecting when the holding position of the dispensing probe relative to the arm deviates from its normal position; a control unit that controls the arm vertical movement mechanism to lower the dispensing probe until it contacts an object below, and after the detector detects that the dispensing probe has deviated from its normal position, to move the dispensing probe upward using the arm vertical movement mechanism; and a determination unit that determines whether or not there is an abnormality in the dispensing mechanism based on a first timing at which the detector no longer detects the displacement of the dispensing probe due to the downward movement of the dispensing probe by the elastic body.

2. An automatic analyzer according to claim 1, characterized in that the object below is the bottom surface of a reaction vessel.

3. An automatic analyzer according to claim 1, characterized in that the detector comprises a member that moves in conjunction with the dispensing probe and a detection mechanism that detects the movement of the member.

4. An automatic analyzer according to claim 1, wherein the determination unit determines whether or not there is an abnormality in the dispensing mechanism based on the probe detachment distance, which is the distance the dispensing probe has moved upward by the first timing.

5. An automatic analyzer according to claim 2, wherein the analyzer has a storage unit for storing the first timing, and the determination unit compares the first timing measured when the dispensing probe descended the previous time with respect to the same bottom surface as the reaction vessel, which is stored in the storage unit, with the first timing measured when the dispensing probe descended the current time, to determine whether or not there is an abnormality in the dispensing mechanism.

6. An automatic analyzer according to claim 1, wherein the analyzer has a storage unit for storing the first timing, and the determination unit compares a preset reference value of the first timing stored in the storage unit with the first timing measured when the dispensing probe descends to determine whether or not there is an abnormality in the dispensing mechanism.

7. An automatic analyzer according to claim 1, wherein the control unit issues an alarm to the measurement result measured using the liquid aspirated and dispensed by the dispensing probe when the determination unit determines that there is an abnormality in the dispensing mechanism.

8. An automated analyzer according to claim 1, wherein the determination unit measures the first timing multiple times in a row and determines that the state of the dispensing probe is appropriate when the first timing becomes substantially constant.

9. An automated analyzer according to claim 1, wherein the analyzer has a plurality of reference values ​​for the first timing, the determination unit compares the first timing measured during the current descent of the dispensing probe with the plurality of reference values, and the control unit performs different processing for each of the plurality of reference values ​​based on the comparison result from the determination unit.

10. An automatic analyzer according to claim 1, comprising: a storage unit for storing information relating to the first timing; and an output unit for displaying information relating to the automatic analyzer, wherein the control unit controls the display of the information relating to the first timing stored in the storage unit to the output unit in chronological order.

11. An automatic analyzer comprising: a dispensing mechanism having a dispensing probe for aspirating and dispensing liquid; an arm for holding the dispensing probe; an arm vertical movement mechanism for moving the arm up and down; and a detector for detecting when the holding position of the dispensing probe relative to the arm deviates from its normal position; a control unit for controlling the arm vertical movement mechanism to lower the dispensing probe until it hits the reaction vessel; and a determination unit for determining the fixing status of the reaction vessel based on a second timing in which the detector detects that the dispensing probe has deviated from its normal position.

12. An automatic analyzer according to claim 11, wherein the arm has an arm cover adjacent to the upper part of the arm that presses the dispensing probe downward, the control unit lowers the dispensing probe using the arm vertical movement mechanism until the dispensing probe contacts the bottom of the reaction vessel, the detector detects that the dispensing probe has shifted from its normal position, and then controls the arm vertical movement mechanism to move the dispensing probe upward, and the determination unit determines that the arm cover is not properly fixed based on a first timing when the detector no longer detects the displacement of the dispensing probe and a second timing.

13. An automatic analyzer according to claim 12, characterized in that the control unit controls the downward movement of the dispensing probe to the reaction vessel to be performed on a reaction vessel block to which a plurality of reaction vessels are fixed, in order to check for defects in the fixing of the reaction vessel and the fixing of the cover of the arm.

14. An automatic analyzer according to claim 13, wherein the determination unit determines that the fixing of the specific reaction vessel is faulty when the first timing and the second timing become abnormal values ​​in the specific reaction vessel.

15. An automatic analyzer according to claim 13, wherein the determination unit determines that the arm cover is improperly fixed when the second timing continuously shows an abnormal value and the first timing is a normal value.

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