JP5337728B2 - Automatic analyzer - Google Patents

Description

  The present invention relates to an automatic analyzer that measures components in a biological sample such as blood and urine, and more particularly to an automatic analyzer that includes a detection mechanism that detects whether an abnormality has occurred during analysis.

  Conventionally, a technique for automatically analyzing components of a biological sample such as blood has been provided. The chemical reaction between the specimen and the reagent is advanced in a dedicated reaction container, the absorbance of the mixture is measured at regular intervals, and the concentration of a predetermined substance present in the biological sample is measured from the change in absorbance over time. In order to improve the reliability of the measured concentration, it is necessary to improve the accuracy of the absorbance data. However, data defects occur due to malfunctions in the mechanism related to dispensing and stirring. For example, when a reagent shortage occurs due to a malfunction of the dispensing function or the like, the data tends to be generally higher than the normal data (701) (702). In addition, when scattering occurs due to a malfunction of the stirring function, a discontinuous difference occurs in the data (703). In addition, the presence of air bubbles may cause sudden highs (spikes) (704). These factors are known to affect the accuracy or accuracy of the measurement results.

  With respect to the above-described problem, Patent Document 1 describes an automatic analyzer that can confirm an analysis operation without opening a dust cover. Japanese Patent Application Laid-Open No. H10-228561 describes a technique for detecting the suction and discharge of a liquid by providing a means for appropriately monitoring the dispensing operation. In addition, Patent Document 3 discloses a method for maintaining the accuracy of the dispensing amount by performing sampling at a certain depth by mounting a liquid level sensor at the tip of the dispensing nozzle. Describes a method for suppressing the generation of bubbles per se by using a deaeration process.

Japanese Patent Laid-Open No. 10-227797 JP 2001-174469 A JP 2002-162403 A Japanese Patent Laid-Open No. 60-064256 Japanese Patent Application Laid-Open No. 08-160054

  By the way, there are a plurality of items that can be measured by the automatic analyzer, and the type of reagent to be dispensed and the amount of the reagent differ for each measurement item. In addition, for one item, it is usual to use a plurality of types such as the first reagent and the second reagent. On the other hand, the reaction containers are not different depending on the measurement items, and all the same containers are used. Therefore, the ideal position of the liquid level differs for each analysis container used and for each kind of dispensed reagent. Under this circumstance, in order to ensure correct dispensing, it is necessary to confirm that each dispensing is performed correctly.

  However, with only the above-mentioned means, it is not possible to confirm during the course of the reaction process that dispensing or stirring has actually been performed properly, and it is necessary to wait for the output of final data for confirmation. It took a lot of time.

  In this regard, a method using an optical system detection method for measuring absorbance is also conceivable as means for detecting foreign matter during the analysis process. Certainly, by performing the above photographing using a photometer, it is considered possible to acquire an image that can detect the liquid surface position and foreign matter simultaneously with the measurement of the absorbance. However, the field of view measured by the photometer is limited to a part of the region where the mixture in the reaction container exists, and there is a limit in detecting the liquid level and foreign matter alone.

  Therefore, the present invention is provided with a means capable of photographing the entire reaction container as a photographing means different from the photometer, so that dispensing and stirring of a plurality of reagents are appropriately performed in synchronization with the measurement process. It is possible to confirm this. At this time, the captured image is subjected to differential processing to emphasize the position of the reaction vessel and the liquid level, and at the same time, information on the state of appropriate dispensing is stored in the apparatus in advance, and the data actually acquired By using the method of comparing the above data, it is possible to more reliably detect the liquid level and foreign matter. Also, based on the relative position relationship between the liquid level and the foreign matter, the foreign matter is scattered and classified by type, such as bubbles, bubbles, and other impurities, so that it is possible to estimate the contents of defects occurring in the device. And Furthermore, it is possible to perform appropriate dispensing and appropriate stirring by performing feedback to the apparatus, such as displaying the result confirmed above with an alarm warning. As described above, the present invention provides an automatic analyzer capable of performing a more reliable analysis by reconstructing a measurement flow to be performed later based on information obtained from a captured image. There is.

  In order to solve the above problems and achieve the object, the automatic analyzer according to claim 1 includes means for photographing the reaction container, means for acquiring and storing the image, and means for analyzing the acquired image. In the course of the measurement process, the reaction vessel is photographed from at least one of the vertical direction or the side according to a predetermined timing programmed in advance, and the acquired images are analyzed, so that multiple reagents are normal in synchronization with the measurement process. It is characterized by having a function of confirming that it has been dispensed. In addition, a function for identifying the positional relationship between the detected liquid level and the foreign matter, a function for distinguishing foreign matters for each type based on this positional information, a function for estimating the cause of occurrence based on the distinguished type, and the above contents in the apparatus It is characterized by having a feedback function.

  According to the analyzer of the present invention, the presence or absence of bubbles, the presence or absence of dirt adhering to the container, the presence or absence of scattering, the amount dispensed, the photometric timing, etc. are checked in synchronization with the analysis. It can be ensured in real time that the measurement process was performed under more optimal conditions. As a result, it is possible to remarkably increase confidence in safe operation and accuracy. It also contributes to cost reduction for users by reducing the number of re-measurements and re-inspections.

1 is a schematic diagram of an automatic analyzer according to the present invention. The figure explaining the means to image | photograph a reaction container. The figure explaining bubble generation | occurrence | production, growth, and detection. The figure explaining the detection of a stirring malfunction. The figure explaining the detection of a dispensing defect. The flowchart showing a determination process. Block diagram showing the flow of measurement. The figure which shows the malfunction of the data by scattering. The figure which shows the malfunction of the data by a bubble. The figure which shows the malfunction of the data by a reagent shortage.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to this embodiment. The following embodiments are representative examples for realizing the basic concept in the above-described invention.

  FIG. 1 is a schematic diagram (upper drawing) showing a configuration of an automatic analyzer (1) according to the present embodiment. The automatic analyzer includes a biological sample transport unit (20), a dispensing mechanism (30), a reaction mechanism (40), a first cold reagent disk (50), and a second cold reagent disk (60) as main functions. I have. A sample is dispensed into a transparent reaction vessel (401) by the dispensing mechanism (301), and a reagent is dispensed by the reagent dispensing mechanism (304, 306) to form a mixture (410) of the sample and the reagent. Next, the function of analyzing the concentration of the substance to be measured contained in the sample by measuring the absorbance of the mixture (410) present in the container at the measuring unit (405) at regular intervals. Prepare.

  The biological sample to be acquired is injected into a dedicated specimen container (203). A fixed number of the containers (203) are installed in the dedicated rack (204) and are put into the automatic analyzer (1). In the transport unit (20), a transport path (201a) of the rack (204) is secured, and the rack (204) is a rail that is laid on the path (201) to prevent shaking and overturning and to adjust the position difference. Move along (202). Each rack (204) is transported to the storage section (206) of the sample disk (205) according to the timing programmed in advance in the system. The accommodated rack (204) is moved to the vicinity of the dispensing mechanism by using the rotating operation of the disk according to the timing programmed in the system in advance, and the reaction container (401) is moved by the specimen sample dispensing mechanism (303). To be dispensed. When dispensing of the sample in the sample container (203) to be transported is completed, the rack (204) is discharged through the discharge path (201b).

  The reaction vessel (401) is installed on the reaction disk (402) which is the main structure of the reaction mechanism (40), and rotates on the reaction disk (402). During the movement, the reagent dispensing mechanism (305, 306) operates according to the timing programmed in advance in the system, and the reagent installed on the reagent disk (501, 601) is dispensed into the reaction container (401). . The dispensing mechanism (30) is composed of a rotating shaft (301), an arm (302), and a nozzle (303), respectively, and the dispensing position is managed with high accuracy through a rotating operation. The reagent disk (501, 601) has a plurality of reagent container storage portions (502, 602), and necessary reagents are arranged in advance. The sample and reagent mixture (410) generated in the dispensing process is stirred by the stirring mechanism (406), and the chemical reaction between the sample and the reagent becomes uniform and the chemical reaction is promoted. In some cases, since it is necessary to stir the reagent itself, each reagent disk (50, 60) is provided with a stirring mechanism (503, 603) dedicated to the reagent.

  The mixture (410) in the reaction vessel (401) passes through the photometry unit (405) at regular time intervals. In the photometry unit (405), the light irradiated from the irradiation light source (403b) is applied to the mixture (410), and the amount of transmitted light is measured. By repeating this a certain number of times, data on the change in absorbance with time is obtained, and the concentration of the measurement object contained in the biological sample is calculated based on the chemical reaction theory. The reaction container (401) that has finished the measurement is washed when it passes through the washing mechanism (407).

  In this automatic analyzer, the irradiation light source (403a) and the reaction vessel (401) are photographed on the reaction disc (402) as a means different from the photometry unit (405) that measures the absorbance of the mixture (410). An imaging mechanism comprising imaging means (404) is provided. Sensors such as CCD, CMOS, and PMT are used for the photographing means. The imaging means (404) is fixed in the reaction mechanism (40) together with the irradiation light source (403) in a state in which the positional accuracy is well maintained.

  FIG. 2 shows details of the above-described photographing mechanism. In the imaging mechanism, the side surface (411) of the reaction container (401) is imaged, and an image of the internal sample and reagent mixture (410) is acquired. When the irradiation light source (403b) is on the opposite side of the imaging means (404) via the reaction disk (402), the imaging means (404) has the irradiation light (420) from the irradiation light source (403b) as a mixture (410). The light (421) that has passed through is photographed. On the other hand, when the irradiation light source (403c) is on the near side with the imaging means (404) via the reaction disk (402), the imaging means (404) is adapted to apply the irradiation light (422) from the irradiation light source (403c) to the mixture ( The light (423) reflected in 410) is photographed.

  By taking an image with such a mechanism and analyzing the acquired image, the dispensing volume (position of the liquid level), the presence or absence of foreign matter, and the location of foreign matter are identified for each dispensing. Can be performed. It is also possible to use a similar method at the start of measurement to confirm that the reaction vessel (401) is indeed empty or that no foreign matter such as dirt is attached.

  The above-described method may be a method in which the photographing means (404) is moved from the outside to the inside or from the inside to the outside of the reaction disk (402) to photograph the opposite side surface of the reaction vessel (401). Alternatively, on the reaction disk (402), a method of photographing from a plurality of sides by rotating the reaction vessel (401) at a revolving speed about the vertical direction as an axis, and optical detection like fibrin is also possible. This is an effective way to facilitate the discovery of difficult substances.

  In addition, the function of moving the imaging means is applied to follow the reaction containers individually, the reaction containers are periodically photographed, and the difference between consecutive images before and after is monitored over time to detect the presence of foreign matter in real time. It is also an effective method to grasp.

  An example of detecting bubbles by this method is shown in FIG. FIG. 3 shows the reaction container (401) photographed over time. An image (401d) captured for the first time after a focused dispensing operation and an image (401e) captured next at regular intervals. Furthermore, the images (401f) taken at regular time intervals are arranged in this order.

  The main cause of the generation of bubbles is a decrease in the amount of saturated gas dissolved in the solution. Many of these phenomena are caused by changes in the environment surrounding the solution such as temperature and pressure after dispensing. Therefore, even if the dispensing is correctly performed, bubbles may be generated in the middle of the analysis, which adversely affects the analysis result. The most effective way to avoid this is to monitor and discover the cells over time.

  When time elapses after dispensing, small bubbles (801, 401e) are generated. As time elapses, bubbles grow (802, 401f). Of these images, 401g and 401h are obtained by taking the difference between the preceding and succeeding images. Since it is the difference between the images before and after, the cell itself and the mixture portion which are not changed are zero on average. However, since there are differences in the irradiating light amount and the luminance fluctuation of the camera itself as strict conditions for imaging, fluctuations peculiar to the imaging system are present.

  With respect to the difference image, (i) a part where a new bubble is generated is an area having a positive luminance (803). On the other hand, if (ii) the already generated bubble moves, or (iii) if the already generated bubble grows, the region has a negative value (804).

  Next, for each image, the χ square root (brightness fluctuation) of the difference from the signal average amount of all images is calculated and recorded in the time series graph (810). The horizontal axis represents time (811), and the vertical axis represents luminance fluctuation (812). When bubbles do not occur, the luminance fluctuation keeps the value (813) peculiar to the above-described imaging system regardless of the passage of time (814). On the other hand, when bubbles are generated, the above-described positive and negative irregularities are formed in the luminance of the image, so that the luminance fluctuation increases and the image rises to the right (815) (816). Here, a reference value (817) is set in advance, and when the luminance fluctuation of the captured image exceeds the reference value, it is recognized that bubbles are generated (818).

  As another method, a method capable of specifying a foreign substance using a physical quantity will be described. In many cases, the foreign matter has characteristics according to the cause of occurrence. An example is the scattering phenomenon. If the stir bar is not properly immersed in the liquid mixture due to insufficient liquid volume and stirring is performed near the liquid level, the liquid on the surface is stirred by the stir bar, causing a large amount of liquid to scatter and continuously inside the analysis container. Liquid is produced. On the other hand, when the dispensed reagent splashes by splashing back into the mixture, dot-like liquid particles are generated on the wall of the analysis container. Taking advantage of such a difference for each cause of occurrence, in the present invention, a feature of the foreign matter is extracted for each cause of occurrence and used to identify the foreign matter.

  An example of this is shown in FIG. FIG. 4a shows splattering due to a failure in the stirring operation, and FIG. 4b shows splattering due to a failure in the dispensing operation.

  In both cases, water droplets (805, 806) due to scattering adhere to the inner side surface of the reaction vessel (401i). The area where the water droplet exists is the upper part of the liquid level when viewed from the bottom, unlike the bubbles (805, 806). In order to detect this feature, the position of the water droplet from the bottom surface is first represented in a graph (820). The horizontal axis is the water droplet number (in order of the detected water droplet number) (821), and the vertical axis is the position (822). The liquid level position (823) of the mixture is also listed. All of the water droplets are located above the water surface (824, 825). From this data, it is determined that the bubble is different. Next, the histogram (830) about an area is calculated | required regarding a water drop. The horizontal axis represents the area (831), and the vertical axis represents the number distribution (832). When the former is due to a malfunction in the stirring operation, the size of water droplets adhering to the side surface of the reaction vessel is different, so the distribution is wide (833). On the other hand, if the latter is due to a malfunction in the dispensing operation, since the size of the water droplet is single, the histogram has a profile having a peak only at one location (834). With the above method, the mechanism causing the problem can be estimated from the scattering state, and feedback to the apparatus by an alarm or the like can be achieved.

  An alternative method for extracting features and identifying foreign objects using statistical data is described. First, a plurality of samples having foreign matters are prepared in advance and classified according to the cause of occurrence. Next, for each cause of occurrence, statistics such as the area, shape, number, and number distribution of the foreign matter are calculated and stored in advance in the apparatus as a standard pattern of the foreign matter. As the number of foreign material samples increases, the standard pattern can be expected to express features more accurately, so the foreign material samples acquired from the previous start-up according to the user's selection at the time of device start-up A function to automatically update the standard pattern based on the information is provided.

  As a similar method, a stochastic neural network is used to grow the extracted pattern, and an appropriate number of foreign matter samples generated due to the occurrence are obtained. A foreign object is specified by matching this with an image of an actual sample acquired immediately after dispensing.

  In addition, as a simpler form of the above method, the pattern of the standard solution is stored as a reference, and by comparing the pattern with the actual sample immediately after dispensing, the presence of foreign matter can be confirmed by the difference from the standard pattern. A method of checking is also effective.

  The flowchart of FIG. 5 shows a method for determining the state of reagent dispensing based on the image of the reaction container. First, the dispensing amount of the reagent is calculated from the position information on the liquid level detected by the above analysis (S0). When the dispensed amount is lower than a preset amount, it is determined that the reagent is insufficient (S1). If there is a reagent shortage, there is no guarantee that an effective analysis result will be obtained, so the reaction vessel is excluded from the measurement process, and at the same time an alarm is displayed to indicate that the reagent is short (S2). On the other hand, if it can be confirmed that a sufficient amount of reagent has been dispensed, then the presence of brightness shading is confirmed (S3). If there is no shading, it is determined that there is no abnormality, and the reaction vessel is advanced to the next process (S4). If there is light and shade, it is determined whether it is a foreign matter such as scattering, bubbles, bubbles or other impurities based on the above-mentioned criteria (S5). If impurities are present, the reaction vessel is excluded from the measurement process in order to increase the reliability of the analysis result (S6). If foreign matter such as splashes, bubbles, bubbles, etc. are present, the positional relationship with the previously detected liquid surface is obtained, and it is confirmed whether the foreign matter is present in the reagent (S7). When the foreign substance exists inside the reagent, it is determined as a bubble (S8). On the other hand, if it is outside, it is determined that it is scattered (S9, S10). Moreover, when it exists on a liquid level, it judges that it is a bubble (S11). Based on these determination results, it is possible to confirm whether the reagent is sufficiently dispensed or stirred, and when it is insufficient, feedback such as an alarm warning is performed. As another feedback method, there is a method of controlling the photographing timing so that the absorbance can be measured while avoiding the position of the bubble when the presence of the bubble is confirmed.

  FIG. 6 is a flowchart showing the system configuration. The above-described imaging mechanism mounted on the automatic analyzer can be mounted on the automatic analyzer as a more effective analysis system by providing the processing procedure described below.

  After obtaining the biological sample, the measurement starts (T0). First, a sample (T1) and a reagent are dispensed (T2) into a predetermined container at a predetermined timing, and after a certain period of time, the reaction container (401) is photographed and an acquired image is analyzed (T4a). Is dispensed (T5a, FIG. 5). After confirming that dispensing has been properly performed, the mixture is stirred (T3) as the next process. After the elapse of a certain time, the image obtained by photographing the reaction container (401) is analyzed again (T4b). Here, from the analysis of the acquired image, the presence of brightness shading is detected, and the presence of foreign matter is determined (T5b, FIG. 5). If it can be confirmed that the operation is normal, the procedure proceeds to a normal procedure, and the measurement is completed (T10) through absorbance measurement (T7), result acquisition (T8), and container cleaning (T9). On the other hand, when it is determined as abnormal in the previous determination (T5a, T5b) result, the cause of the malfunction is estimated based on the analysis result (T4a, T4b, FIG. 5) (T11).

  Subsequent procedures are divided into the following two.

  1) If the number of times that a defect has been detected is within a predetermined number of times set in advance (T12), re-measurement is performed. At this time, re-measurement is started from a step that affects the cause estimated from the result of the image analysis. For example, when the determination result that the liquid amount is small is obtained from the result of the image analysis, remeasurement is started from the liquid dispensing or reagent dispensing steps (T1, T2). When the result that the stirring is insufficient is obtained, the process is executed from the stirring step (T3).

  2) When the number of times that a failure has been detected exceeds a predetermined number of times set in advance (T12), the apparatus performs self-maintenance (T13). Self-maintenance is a function provided in advance in the apparatus. Perform maintenance such as cleaning and operation check of the mechanism that affects the cause of failure estimated from the image analysis results described above. For example, when a malfunction in the liquid volume reduction is detected from the result of the image analysis, the nozzle pressure is checked to check for clogging. If clogging is present, cleaning or air jet elimination is attempted. If abnormal stirring is observed, various functions such as the number of rotations of stirring are checked, and if necessary, recovery to a normal state is attempted. Thereafter, the user's intention to continue the measurement is confirmed. If there is, the analysis is continued. If there is not, the apparatus is stopped through a cleaning process.

  In addition, in order to shorten the calculation time and the calculation capacity in image analysis, use the specificity of the reagent to narrow down the points to be checked and select the minimum necessary contents instead of all the points in the above flow. This method is also effective. For example, it is possible to identify more accurately by preliminarily grasping the form of a foreign substance that is likely to be generated for each of the standard solution, blank solution, and quality control substance, and intensively determining the cause of the occurrence.

  As another method, the shape of the reaction container (401) is changed for each measurement item so that the liquid level becomes the same level when the reagent is appropriately dispensed for any item. Good. By setting in this way, it becomes possible to more easily determine an appropriate amount of dispensing.

  It is also effective to have a function of selecting an appropriate check method for each type of reagent to be dispensed as well as the characteristics of the reagent.

DESCRIPTION OF SYMBOLS 1 Automatic analyzer 20 Biological sample conveyance part 30 Dispensing mechanism 40 Reaction mechanism 50 1st cold storage reagent disk 60 2nd cold storage reagent disk 201 Transfer path 202 Rail 203 Sample container 204 Sample rack 205 Sample disk 206 Rack storage part 301 Rotating shaft 302 Arm 303 Nozzle 401 Reaction vessel 402 Reaction disk 403 Irradiation light source 404 Imaging means 405 Measurement unit 406 Stirring mechanism 407 Washing mechanism 410 Mixture 411 Reaction vessel side surface 412 Boundary (liquid level)
420 Irradiation light (when shooting with transmitted light)
421 Transmitted light 422 Irradiated light (when shooting with reflected light)
423 Reflected light 501 Reagent disc (first reagent)
502 Reagent container storage (first reagent)
503 Reagent stirring mechanism (first reagent)
601 Reagent disc (second reagent)
602 Reagent container storage (second reagent)
603 Reagent stirring mechanism (second reagent)
701 Ideal absorbance curve 702 Step due to scattering 703 Spike due to bubbles 704 Shift due to lack of reagent 801 Bubble generation 802 Bubble growth 803 Positive luminance 804 Negative luminance 805 Scattering (stirring failure)
806 Spattering (dispensing failure)
810 Time-series graph 811 Time 812 Luminance fluctuation (χ-square root)
813 Imaging system specific value 814 When no bubble is generated 815 Arrow 816 indicating rising of right shoulder 816 When bubble is generated 817 Reference value for determining bubble generation 818 Time when bubble generation is recognized 820 Graph 821 indicating position of water droplet Water drop number 822 Water drop position 823 Liquid surface position 824 Water drop position data (stirring failure)
825 Water drop position data (dispensing failure)
830 Graph showing a histogram of water drop area 831 Water drop area 832 Water drop number distribution 833 Water drop histogram data (stirring failure)
834 Water drop histogram data (dispensing failure)

Claims (4)

In an apparatus for measuring a chemical reaction in a reaction container by reacting a sample and a reagent, the apparatus includes means for photographing the reaction container, means for acquiring and storing an image, and means for analyzing the acquired image.
After dispensing the reagent, after a predetermined time has elapsed, the reaction container is photographed from at least one of the vertical direction and the side surface, and the means for analyzing the image is configured to calculate the difference between the images before and after the photographed image over time. An automatic analyzer characterized by monitoring, calculating luminance fluctuation obtained from the difference, and determining that bubbles are generated when the luminance fluctuation exceeds a predetermined threshold. An automatic analyzer according to claim 1, taking the reaction vessel prior to dispensing of samples and reagents, by analyzing the acquired image, that the reaction container is empty, and the reaction vessel Automatic analyzer with a function to check the presence or absence of dirt.   The automatic analyzer according to claim 1, comprising a medium that stores in advance the specificity of each reagent, such as a standard solution, a blank solution, a quality control substance, a calibration substance, and the like, dispensed from the information An automatic analyzer equipped with means capable of selecting an appropriate checkpoint according to the situation.   The automatic analyzer according to claim 1, comprising means for holding reaction containers having different shapes and means for selecting a reaction container having a dedicated shape for each analysis item, and a reaction container corresponding to the analysis item By using the function, when the dispensing amount of different reagents for each item is correctly dispensed, it has the function that the position of the liquid level can be fixed regardless of the analysis item Automatic analyzer.

Images