JP2012108061A - Automatic analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deterioration diagnosis function and a deterioration specification notification method that can automatically specify a deterioration portion by monitoring secular deterioration.SOLUTION: The configuration of a motor controller 001 is shown in Fig.1. The motor controller 001 drives a stepping motor by using an output pulse. In the motor controller 001, a prediction computing element 004 is mounted to predict the present position of a drive target 008 by using a specific variable that the drive object 008 to be driven by the motor has in calculation. A sensor input from the target object 008 to be driven by the motor is received by an output pulse monitoring device 003 and is compared with information in the prediction computing element 004 by a comparator 006 to discriminate whether or not an abnormality occurs in the drive target 008.

Description

  The present invention relates to an automatic analyzer that analyzes biological samples such as blood and urine, and more particularly to an automatic analyzer that drives a reaction disk, in which reaction containers for reacting a sample and a reagent are arranged in a row, by a motor.

  In an automated analyzer that analyzes the components to be measured in a sample using the biochemical reaction between the sample and the reagent, a reaction in which a number of reaction vessels are arranged in a line to increase the number of analyzable units per unit time. An analysis apparatus called single-line multi-item analysis (single multi) in which a disk is driven to rotate and react in parallel with a certain time difference in each reaction vessel is the current mainstream. In this analyzer, the reaction process (absorbance change) in all reaction containers can be traced by the reaction containers on the reaction disk continuously crossing the photometric optical axis whose position is fixed. In order to accurately measure the change in absorbance during the reaction process, it is necessary to know exactly when each reaction vessel crosses the photometric optical axis, and to measure the absorbance (usually measured within a given time). It is necessary to make the integrated value of the absorbance and the average value of the absorbance at a plurality of points the same in any reaction vessel. As a method for measuring the timing at which the reaction container crosses the front of the photometric optical axis, a method described in Patent Document 1 is known.

JP-A-9-80055

  In the technique described in Patent Document 1, since the detection plate for detecting the position of the reaction cell is integrated with the reaction cell, the position detection accuracy can be ensured to be constant.

  However, in automated analyzers, the volume of biological samples and reagents has been decreasing, and the dimensions of the reaction container (reaction cell) are on the order of 1 millimeter, while the dispensing nozzle for aspirating and discharging reagents and specimens has There is a demand for handling liquid quantities on the order of 1 microliter. As a result, it is necessary to drive the reaction mechanism including the drive source and the transmission unit with considerable accuracy.

  Further, in order to achieve a high throughput of analysis processing, the drive unit in such an apparatus is required to have high-speed mobility, and the time during which the position adjustment using the feedback means is performed with respect to the drive of the drive target is not allowed.

  On the other hand, in order to mount a product at a low price, it is conceivable to employ a relatively inexpensive stepping motor as a driving source and a driving belt to transmit driving force. In this case, it is not possible to eliminate the possibility of aging deterioration even within the interval of periodic replacement of the drive belt depending on the operating time and operating environment. It is important to discover.

  By definition, failures due to aging are difficult to detect by pre-shipment inspection.

  In addition, periodic equipment inspection is advantageous from the viewpoint of completeness, but there is a difference in the progress of deterioration of the equipment depending on the operating environment and operation time. It is difficult to find a failure, and it is also disadvantageous from the viewpoint of efficiency.

  On the other hand, periodic replacement of parts can reduce the probability of these occurrences, but it is difficult to reliably remove such occurrences.

  Such aging has the potential to induce sudden failures. A sudden change in inertia of the drive unit due to the disconnection of the drive belt may cause damage or scattering of the specimen, which is a problem that cannot be overlooked as the reliability required for medical devices. It is not acceptable as a stable driving performance.

  An object of the present invention is to provide an automatic analyzer that can prevent a failure from occurring by detecting a malfunction of a rotational drive system of a reaction disk with high accuracy.

  The configuration of the present invention for achieving the above object is as follows.

  In an automatic analyzer comprising a reaction vessel for reacting a sample and a reagent, a reaction disk in which the reaction vessels are arranged in a row, and a motor for rotationally driving the reaction disk, the reaction vessel corresponds to each position of the reaction vessel. In addition to the position detection marker, an origin detection marker corresponding to a specific position of the reaction vessel, and the origin An automatic analyzer comprising: a second detector that detects a detection marker.

  In general, reaction disks are arranged such that reaction vessels are arranged in a row on a disk or ring and have a rotation axis in the vicinity of the center, but the reaction vessels are arranged in a row and can be rotated. Anything is acceptable. Any type of motor may be used, but using a stepping motor can achieve both accuracy and cost. The position detection marker and the origin detection marker may be any as long as their relative positions do not change and can be detected by a detector. The position detection marker is preferably, for example, a comb in which comb-like projections are arranged at regular intervals (in this case, it may be called a detection plate). In addition, since the origin detection marker only needs to be able to specify the position of one point, the degree of freedom in shape is higher than that of the position detection marker. Needle-like ones can also be used. A detector that captures an optical change is preferable because it can achieve both accuracy and cost. However, any detector that can detect the position may be used. For example, a device that measures a change in electrical resistance, a change in capacitance, or the like, or a detector plate that is made of a magnetic material and that detects the strength of a magnetic field such as a Hall element may be used.

  Prevent failures due to deterioration over time and reduce the cost of countermeasures for sudden failures. Further, it is possible to find a potential failure depending on the operation status of the apparatus without performing periodic inspection, and the failure can be found efficiently. In addition, it is possible to avoid damage to the specimen and provide a highly reliable and highly stable operating environment of the medical examination apparatus at low cost.

The circuit structure of this invention. Reaction disk mechanism. Explanatory drawing of a detection board. Distribution graph. Failure identification mode

  An example of the embodiment of the present invention will be described with reference to FIG. The motor controller 001 includes a pulse generator 002, an output pulse monitor 003, a prediction calculator 004, a sensor input monitor 005, a comparator 006, and a memory 007. The pulse generator 002 outputs a pulse to drive the drive target 008 to the target position at the requested speed. The output pulse monitor 003 records the number of pulses output by the pulse generator 002 and the pulse width. The prediction calculator 004 uses the variables specific to the system constituting the drive target 008 and the drive target 008 with respect to the number of pulses and the pulse width, which are the input information recorded in the output pulse monitor 003, and the drive target 008. Is calculated as output information. The sensor input monitor 005 is a sensor input for confirming the position information of the drive target 008. This sensor is not used for the purpose of position control, and the drive target 008 moves beyond the allowable range. It is intended to be fail-safe so as not to cause damage by colliding with other components. In the present invention, the sensor input monitor 005 is actively used as input information of the motor controller 001, and the drive target 008 and the location that induces a failure in the system constituting the drive target 008 are specified. The comparator 006 compares the input values from the prediction calculator 004 and the sensor input monitor 005 and stores the comparison result in the memory 007. The result stored in the memory 007 is referred to when identifying a potential fault described later. The LED 116 is an operation state display LED, and displays the operation state of the motor controller 001. Next, an example of the drive target 008 in the present invention will be described with reference to FIG.

  FIG. 2 shows a reaction disk 103 having a test tube and a rotating mechanism having a driving stepping motor 101 as a driving source and a driving belt 102 as a transmission unit, which is cited as an example of the driving object 008. The test tube is called a reaction cell 104 and is used to analyze a biological sample using a biochemical reaction. The driving stepping motor 101 provides power to the rotation mechanism in accordance with an output pulse from the motor controller 106 via the motor driver IC 105. In this example, the drive target is a reaction disk 103 having a disk shape, and a reaction cell 104 is mounted on the circumference of the reaction disk 103. The reaction disk 103 is fixed to a disk rotating table 107, and both are attached to the disk rotating shaft 108 so as to share the same axis. A reaction tank 109 in the figure is a path through which hot water of a constant temperature flows in order to maintain the sample and reagent in the reaction cell 104 at an optimal temperature for the intended biochemical reaction. The reaction tank 109 is attached to the fixed stage 110 and is mechanically separated from the system composed of the reaction disk 103 and the reaction cell 104. Further, the reaction disk 103 is mounted with a reaction cell counting plate 111 and a disk origin detection plate 112. The mounting purpose of the reaction cell counting plate 111 and the disk origin detection plate 112 will be described later. A driving belt 102 is a transmission portion of the driving stepping motor 101. The drive belt 102 includes a motor turntable 113 and a bottom circumference of the disc turntable 107. The motor rotating plate 113 is connected to a motor rotating shaft 114, and the motor rotating shaft 114 is supported in the driving stepping motor 101 by a motor bearing 115. Next, the reaction cell counting plate 111 and the disk origin detection plate 112 will be described with reference to FIG.

  FIG. 3 is a schematic diagram showing the relative positions of the reaction cell 104 on the circumference of the reaction disk 103, the reaction cell counting plate 111 and the disk origin detection plate 112. The reaction cell counting plate 111 has a saw blade shape, and the total number of saw blades is equal to the total number of reaction cells 104. By installing an optical sensor so that the optical axis is perpendicularly incident on the surface of the reaction cell counting plate 111, the saw blade acts as a slit and counts the number of reaction cell counting plates 111, that is, the reaction cells 104. be able to. On the other hand, a disk origin detection plate 112 having a similar detection form is used for the purpose of detecting the origin on the reaction disk 103 with respect to the reaction cell 104. The optical sensor here refers to a light source with high directivity such as a laser, and the dispersion of luminous intensity with respect to the optical axis can be ignored.

  Next, a means for detecting a location that induces a failure and a means for specifying the type will be described. As described above, since the mechanical accuracy required for an automatic analyzer is high, the dimensional error generally possessed by the device is unique to the device, and the type of potential failure can be determined by uniform judgment criteria. It cannot be specified. In the present invention, after the comparison result stored in the memory 007 mounted by the motor controller 001 is accumulated / analyzed and the mechanical error specific to the apparatus is identified using the history of the comparison result. It provides a means for identifying the type of potential failure.

  Examples of the comparison result stored in the memory 007 include the difference between the output pulse monitor 003 and the sensor input monitor 005 calculated by the comparator 006, and the drive occurrence probability that obtained the difference. Here, it is assumed that the rotating system shown in FIG. 2 is mounted with an operation mode called a maintenance mode, and the rotating system is driven in a self-diagnosis mode different from that during normal apparatus operation. During normal operation, the lit LED 116 starts blinking in the maintenance mode based on the stored contents of the LED control register 009 that controls the display of the LED, and the cycle is 1 Hz. In this maintenance mode, if the difference calculation result Δt between the output pulse monitor 003 and the sensor input monitor 005 with respect to the time required for the reaction disk 103 to make one rotation, the occurrence probability P () of the drive in which the required Δt is obtained. A distribution map as shown in FIG. 4 is obtained for Δt). The vertical axis represents P (Δt), and the horizontal axis represents Δt. As a cause of the occurrence of such variations, variations in slit dimensions can be considered. It should be noted that the completion of the one-rotation driving is achieved when the slit count based on the sensor output becomes equal to the number of reaction cells 104, and the sensor input monitor 005 measures the time from the start to the completion of the count. it can. During the maintenance mode time, the comparator 006 determines the result of the difference between the movement predicted value of the prediction calculator 004 and the arrival time obtained from the sensor output, and the contents are stored in the memory 007.

  Next, determination criteria provided by the present invention will be described. Since the variation as shown in FIG. 4 is different for each inspection apparatus, it is as described above that obtaining a unique determination standard for each apparatus becomes a problem. The present invention determines that a potential abnormality has occurred on the horizontal axis in FIG. 4 when a difference longer (or shorter) than 3σ than the average value μ of Δt is measured. Since FIG. 4 shows the characteristic unique to the apparatus obtained depending on the operation history of a certain inspection apparatus, different determination criteria can be provided between products by adopting this determination method. Here, σ is the standard deviation of the required time difference with respect to the total number of maintenance mode trials.

  The aforementioned slit dimension variation is considered to be within the range of normal operation, but abnormal operation that can occur in the mechanism characterized in FIGS. There is deflection and deviation of the motor rotation shaft 114 due to wear of the motor bearing 115 of the driving stepping motor 101. Further, as an event that is normal but may be determined to be abnormal, there is a sensor misrecognition due to condensation adhering to the reaction cell counting plate 111. Both the deflection and the deviation of the motor rotating shaft 114 can be visually detected as deterioration progresses. However, the present invention specifies the possibility of failure before it can be visually detected. There is provided a means for determining that there is a sensor misrecognition as a normal operation.

  When it is determined that there is an abnormality based on this determination criterion, the operation mode is shifted from the maintenance mode to the operation mode for identifying the cause of occurrence. Since the blinking period is changed at the same time as the transition to the LED 116 abnormality cause identification mode that has been blinking at 1 Hz in the maintenance mode, the user can confirm that the mode has shifted. The blinking cycle in the cause identification mode is 0.5 Hz. The operation flow in this mode will be described with reference to FIG. The first identification means is a method for detecting condensation adhering to the reaction cell counting plate 111 using the disk origin detection plate 112. The time required for one rotation is measured by counting the reaction cells 104 with the reaction cell counting plate 111, and at the same time, the required time is simultaneously measured using the disk origin detection plate 112 and the optical sensor. The reaction cell counting plate 111 and the disk origin detection plate 112 are measured, and the reaction disk 103 is rotated for the same time, and the disk origin detection plate 112, which is the only on-circumference detection plate, has dimensional variations. I can't. In this way, if there is a difference in the time for one rotation between the reaction cell counting plate 111 and the disk origin detection plate 112, it is determined that the required time difference is due to condensation on the reaction cell counting plate 111.

  The second cause identifying means measures the time required for n rotations and identifies wear of the motor bearing 115 of the driving stepping motor 101. When the driving stepping motor 101 is transmitted by the driving belt 102 as shown in FIG. 2, a load is always applied in the direction perpendicular to the disk rotation shaft 108. Due to this load, the motor bearing 115 in the driving stepping motor 101 is worn, and the motor rotation shaft 114 is inclined with respect to the Z direction. Due to this inclination, the frictional force between the motor rotating shaft 114 and the motor bearing 115 increases, and the motor output of the driving stepping motor 101 decreases. This decrease is recognized as a delay time by the above-described reaction cell counting plate 111 and the disc origin detection plate 112 both detection plates. Further, since this frictional force always causes a decrease in motor output while the motor rotating shaft 114 is rotating, assuming that this delay time is Δt1 per rotation, the total delay is (n * Δt1) at n rotations. Thus, it can be distinguished from the time difference caused by the deflection of the belt described in the third specifying means.

  The third cause identifying means measures the time required for one rotation and the time required for n rotations acquired in the first and second, and checks whether or not a time difference is propagated. It is to identify the deflection. The drive belt 102 is inevitably bent due to aging, and if left untreated, the drive belt 102 may be disconnected. The deflection of the driving belt 102 increases play at the contact portion between the motor rotating disk 113 and the disk rotating table 107 and the driving belt 102. This increase is recognized as a difference in the measurement in the time required for one rotation, but the difference is not propagated when the motor bearing 115 is rotated n times as in the case of wear. Based on this characteristic, the deflection of the drive belt 102 can be determined.

  In the present invention, the user can be notified by a different display method for each identified cause. When the comparator 006 recognizes that the difference is a potential failure, it writes the specific result into the bits of the facilitated register in the motor controller 001. When this write access occurs, the motor controller 001 issues an interrupt request signal to the host CPU, and the host CPU reports to the user via the GUI. The motor controller 106 that has recognized the potential of failure cannot return the LED blinking at the cycle of the abnormality identification mode to lighting during normal operation. This is intended to maintain the reliability required for medical devices. If the maintenance mode is set to be performed every time the power is turned on, the failure is not detected and normal operation is not performed unless the potential for failure is improved by the maintenance inspector.

001, 106 Motor controller 002 Pulse generator 003 Output pulse monitor 004 Prediction calculator 005 Sensor input monitor 006 Comparator 007 Memory 008 Drive target 009 LED control register 101 Drive stepping motor 102 Drive belt 103 Reaction disk 104 Reaction cell 105 Motor driver IC
107 Disc rotating table 108 Disc rotating shaft 109 Reaction tank 110 Fixed stage 111 Reaction cell counting plate 112 Disc origin detection plate 113 Motor rotating plate 114 Motor rotating shaft 115 Motor bearing 116 LED

Claims (7)

In an automatic analyzer comprising a reaction container for reacting a sample and a reagent, a reaction disk in which the reaction containers are arranged in a row, and a motor for rotationally driving the reaction disk,
A position detection marker corresponding to each position of the reaction vessel, and a first detector for detecting the position detection marker,
In addition to the position detection marker, an origin detection marker corresponding to a specific position of the reaction vessel, a second detector for detecting the origin detection marker,
An automatic analyzer characterized by comprising: The automatic analyzer according to claim 1, wherein
The automatic analyzer according to claim 1, wherein the motor is a stepping motor. The automatic analyzer according to claim 1, wherein
An automatic analyzer that mounts a display LED control register in a motor controller that controls the stepping motor, and mounts a motor controller that can change the lighting and blinking cycle depending on the operation mode. The automatic analyzer according to claim 1, wherein
2. The automatic analyzer according to claim 1, wherein the detector is a photo interrupter that detects a marker based on the fact that the marker blocks light. The automatic analyzer according to claim 2,
A controller for controlling the rotation of the stepping motor;
An output pulse monitor that records the number of pulses and a pulse width for rotating the stepping motor output by the controller, and a predetermined position from the current position of the reaction disk based on the pulse information recorded in the output pulse monitor An arithmetic unit that calculates an expected arrival time until rotation to a position, an expected arrival time predicted by the arithmetic unit, and a current position measured by the first detector and the second detector from a current position to a predetermined position. An automatic analyzer comprising: a comparator for comparing arrival times until rotation. The automatic analyzer according to claim 4,
The automatic analysis apparatus characterized in that the arrival time comparison is performed in a maintenance / inspection mode different from the normal operation mode, and has transition means for transitioning to the maintenance / inspection mode. The automatic analyzer according to claim 5, wherein
An automatic analyzer comprising a notification means for comparing the arrival times and notifying when there is a divergence exceeding a predetermined value.

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