Automatic analyzer and liquid level detection method

Abstract

To provide an automated analysis device and a liquid surface detection method capable of detecting a liquid surface position of a sample regardless of saturation and transparency of the sample.SOLUTION: An automated analysis device comprises: a rack conveying path 141 for transporting a sample rack 2 accommodating a sample container 3 containing a sample 4; a camera 5 provided to a side part of the rack conveying path 141; and a control section 10 for controlling the rack conveying path 141 and the camera 5. The control section 10 stops the transportation of the sample rack 2 being transported by the rack conveying path 141, captures the sample container 3 accommodated in the sample rack 2 of which transportation has been stopped a plurality of times by the camera 5, acquires a plurality of captured images of the sample container 3, generates differential images of the plurality of captured images, and a region having the largest area among regions having a time variation in the differential images is defined as a position of a liquid surface 41 of the sample 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an automatic analyzer for analyzing a sample and a liquid level detection method for detecting the liquid level of a sample. [Background technology]

[0002] Automated analyzers analyze samples such as blood or urine by reacting them with reagents and measuring the absorbance or luminescence intensity of the reaction mixture. It is desirable for automated analyzers to quickly determine when a sample is low in volume in order to eliminate unnecessary tests, reduce the consumption of consumables and reagents, and improve the reliability of test results. To address this issue, a method has been proposed that uses image processing to detect the liquid level of the sample and estimate the sample volume based on the detected liquid level.

[0003] For example, Patent Document 1 describes an example of a sample analyzer that detects the liquid level of a specimen contained in a sample container. The sample analyzer described in Patent Document 1 uses a camera to capture an image of a sample container lifted from a sample rack using a gripper, and detects the position of the pixel where the cumulative value of red and blue brightness along the height direction of the sample container in the captured image, or the ratio of these cumulative values, changes to or exceeds a threshold, as the liquid level. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-038659 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, the liquid level of a specimen is detected using color information of the specimen in an image captured by a camera, so there is a possibility that the liquid level of the specimen cannot be detected if the specimen has low saturation and high transparency, etc. Also, in order to capture an image of the specimen container (hereinafter referred to as "specimen container") with a camera, a mechanism is required to remove the specimen container from the sample rack (hereinafter referred to as "specimen rack").

[0006] The object of the present invention is to Yo The present invention provides an automatic analyzer and a liquid level detection method that can detect the liquid level of a sample without using a liquid level detector. [Means for solving the problem]

[0007] The automated analyzer according to the present invention comprises a rack transport path for transporting sample racks containing sample containers, a camera provided on the side of the rack transport path, and a control unit for controlling the rack transport path and the camera. The control unit stops the transport of the sample rack being transported by the rack transport path, takes multiple images of the sample containers stored in the sample rack while transport is stopped with the camera, obtains multiple images of the sample containers, creates a difference image between the multiple images, and determines the area with the largest area that changes over time in the difference image as the position of the liquid surface of the sample.

[0008] The liquid level detection method according to the present invention comprises the steps of transporting a sample rack containing sample containers along a rack transport path, stopping the transport of the sample rack being transported along the rack transport path, taking multiple images of the sample containers stored in the sample rack while transport is stopped using a camera to obtain multiple images of the sample containers, creating a difference image of the multiple images, and determining the area in the difference image that has the largest area and changes over time as the position of the liquid level of the sample. [Effects of the Invention]

[0009] According to the present invention, the saturation and transparency of the specimen are Yo It is possible to provide an automatic analyzer and a liquid level detection method that can detect the liquid level of a sample regardless of the amount of liquid. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a top view showing an outline of the configuration of an automatic analyzer according to a first embodiment of the present invention. [Figure 2A] FIG. 10 is a diagram illustrating the pitch of a multi-sample rack. [Figure 2B] FIG. 10 is a diagram illustrating the pitch of a single-piece sample rack. [Figure 3] FIG. 1 is a diagram showing schematic diagrams illustrating examples of captured images of a specimen container taken by a camera at time intervals Δt, arranged in order of image capture time from (a) to (i). [Figure 4] FIG. 10 is a diagram showing an example of the change over time in the transport speed V of the sample rack. [Figure 5A] 4 is a schematic diagram showing an example of an inter-image difference image created using the three captured images (a) to (c) in FIG. 3. FIG. [Figure 5B] 4 is a schematic diagram showing an example of an inter-image difference image created using three captured images, captured image (d) to captured image (f) in FIG. 3. FIG. [Figure 5C] 4 is a schematic diagram showing an example of an inter-image difference image created using three captured images, captured image (g) to captured image (i) in FIG. 3. FIG. [Figure 6] FIG. 10 is a top view showing an outline of the configuration of a specimen supplying unit provided in an automatic analyzer according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the automatic analyzer and liquid level detection method according to the present invention, the transport of a sample rack containing sample containers is stopped, and the sample containers are imaged multiple times while the transport of the sample rack is stopped and the sample liquid surface continues to sway, and the position of the sample liquid surface is detected based on an area that changes over time in the multiple images obtained. Yo Furthermore, the automated analyzer and liquid level detection method according to the present invention can image sample containers without removing them from the sample rack, eliminating the need for a mechanism for removing sample containers for imaging, and shortening the time required to detect the sample liquid level, thereby preventing a decrease in the throughput of the automated analyzer.

[0012] An automatic analyzer and a liquid level detection method according to an embodiment of the present invention will be described below with reference to the drawings. The liquid level detection method according to the present invention is not limited to automatic analyzers, but can be applied to any device that detects the liquid level. In the drawings referred to in this specification, the same or corresponding components are designated by the same reference numerals, and repeated description of these components may be omitted. [Example]

[0013] 1 is a top view showing an outline of the configuration of an automatic analyzer 1 according to a first embodiment of the present invention. The automatic analyzer 1 includes a sample supply unit 12 having an inlet 123 and an outlet 124 for a sample rack 2, an analysis module 13 that dispenses a fixed amount of sample 4 and performs measurement, a transport unit 14 that transports the sample 4, and a control unit 10 that controls the automatic analyzer 1. Although the control unit 10 is shown in FIG. 1 installed inside the sample supply unit 12, it can be installed at any position on the automatic analyzer 1. Alternatively, the control unit 10 may be installed outside the automatic analyzer 1 and control the automatic analyzer 1 by communicating with the automatic analyzer 1.

[0014] The specimen 4 is a liquid such as blood or urine, and is contained in a specimen container 3. In the automatic analyzer 1, the specimen container 3 containing the specimen 4 is transported while being stored in a specimen rack 2 in order to protect the specimen 4 and improve workability.

[0015] The sample rack 2 stores sample containers 3 containing samples 4. The sample rack 2 may be a multi-sample rack that can store multiple sample containers 3, or a single-sample rack that stores one sample container 3. In Figure 1, arrow D indicates the direction in which the sample rack 2 is transported.

[0016] The sample supply unit 12 is equipped with a barcode reader 115. The sample container 3 is equipped with a barcode label for sample identification. In this embodiment, it is assumed that a barcode label is affixed to the sample container 3. The barcode reader 115 can read the barcode label of the sample container 3 located at the barcode reading position 126. The control unit 10 identifies the sample 4 placed in the sample container 3 based on the information obtained from the barcode label read by the barcode reader 115, and assigns the sample 4 to a destination analysis module 13 in the sample rack 2 according to the identified sample 4.

[0017] The transport unit 14 includes an incoming rack transport path 141 and an outgoing rack transport path 142. The incoming rack transport path 141 transports the sample rack 2 from the sample supply unit 12 to the analysis module 13. The outgoing rack transport path 142 transports the sample rack 2 from the analysis module 13 to the sample supply unit 12. The incoming rack transport path 141 and the outgoing rack transport path 142 can be configured by, for example, a belt.

[0018] The analysis module 13 is equipped with a camera 5 and a light 6 on the side of the loading rack transport path 141. The camera 5 is focused on the rack transport path 141 and captures images of the sample containers 3 and the samples 4 contained in the sample containers 3. The light 6 is installed on the same side of the rack transport path 141 as the camera 5 and illuminates the rack transport path 141, irradiating light onto the sample containers 3. The light 6 may irradiate light onto the sample containers 3 only when the camera 5 captures an image of the sample containers 3.

[0019] The control unit 10 controls the sample supply unit 12, the analysis module 13, the transport unit 14, the barcode reader 115, the camera 5, and the lighting 6. For example, the control unit 10 controls the transport unit 14 to transport the sample rack 2, the camera 5 to capture images of the sample containers 3, and the lighting 6 to irradiate the sample containers 3 with light.

[0020] The control unit 10 moves the sample rack 2 in pitch units, which will be described later, and stops the movement of the sample rack 2 at a position where the position of one of the sample containers 3 stored in the sample rack 2 coincides with the focal position 7 of the camera 5. The camera 5 is controlled by the control unit 10 to capture images of the sample container 3 at the focal position 7 of the camera 5 multiple times while the movement of the sample rack 2 is stopped. After capturing an image of the sample container 3, the control unit 10 moves the sample rack 2 in pitch units and stops the movement of the sample rack 2 at a position where the position of the next sample container 3 (the sample container 3 adjacent to the imaged sample container 3) coincides with the focal position 7 of the camera 5. The camera 5 captures images of the sample container 3 at the focal position 7 of the camera 5 multiple times while the movement of the sample rack 2 is stopped.

[0021] The control unit 10 repeats the above process, taking images of each sample container 3 multiple times with the camera 5 while the transport of the sample rack 2 is stopped, and obtains multiple images of the sample containers 3 stored in the sample rack 2 whose transport has stopped.

[0022] The automatic analyzer 1 may be equipped with a display device (not shown), and the automatic analyzer 1 may be connected to a display device.

[0023] The pitch in the above description will be explained with reference to FIGS. 2A and 2B.

[0024] Fig. 2A is a diagram illustrating the pitch p for a multi-sample rack 2a. Fig. 2B is a diagram illustrating the pitch p for a single-sample rack 2b. Fig. 2A shows, as an example, a multi-sample rack 2a that can store five sample containers 3.

[0025] As shown in Figures 2A and 2B, the central axis of the sample container 3 is represented by the symbol C. The sample container 3 contains a sample 4, and has a barcode label 31 affixed thereto for identifying the sample. The barcode label 31 is affixed to a portion of the circumference of the sample container 3. The barcode label 31 From the gap The camera 5 can capture an image of the specimen 4 contained in the specimen container 3 .

[0026] The pitch p is the distance between the central axes C of adjacent sample containers 3 stored in the sample rack 2 (2a, 2b). In the multi-sample rack 2a, the pitch p is the distance between the central axis C of one sample container 3 in one sample rack 2a and the central axis C of the sample container 3 adjacent to this sample container 3, as shown in FIG. 2A. In the single-sample rack 2b, the pitch p is the distance between the central axis C of a sample container 3 stored in the sample rack 2b and the central axis C of a sample container 3 stored in the sample rack 2b adjacent to this sample rack 2b, as shown in FIG. 2B.

[0027] 2A, the control unit 10 stops the transfer of the sample rack 2a at a position where the central axis C of one sample container 3 coincides with the focal position 7 of the camera 5, and while the transfer of the sample rack 2a is stopped, the camera 5 captures images of this sample container 3 multiple times. After capturing the images of this sample container 3, the control unit 10 transfers the sample rack 2a by a pitch p. The control unit 10 repeats the above process for five sample containers 3.

[0028] 2B, the control unit 10 stops the transfer of the sample rack 2b at a position where the central axis C of the sample container 3 stored in the sample rack 2b coincides with the focal position 7 of the camera 5, and causes the camera 5 to capture images of the sample container 3 multiple times while the transfer of the sample rack 2b is stopped. After capturing the images of the sample container 3, the control unit 10 moves the sample rack 2b storing the sample container 3 and the sample rack 2b adjacent to it by a pitch p. The control unit 10 repeats the above process for multiple sample racks 2b.

[0029] The time interval and duration for which the camera 5 captures images of the sample containers 3 while the transport of the sample rack 2 is stopped can be determined based on, for example, the acceleration and speed of the transport of the sample rack 2, and the magnitude of vibration of the sample containers 3 after the sample rack 2 is stopped. The number of times that the camera 5 captures images of the sample containers 3 while the transport of the sample rack 2 is stopped can be determined based on, for example, the time interval and duration for capturing images, and is preferably at least three times.

[0030] The principle of the liquid level detection method according to the embodiment of the present invention will be described with reference to Figures 3 and 4. The automatic analyzer according to the embodiment of the present invention detects the liquid level of the specimen 4 using this liquid level detection method.

[0031] 3 is a diagram showing example schematic diagrams of captured images of a sample container 3 captured by a camera 5 at time intervals Δt, arranged in order of capture time from (a) to (i). The schematic diagram of the captured image shown in FIG. 3 shows a sample rack 2, a sample container 3 stored in the sample rack 2, a sample 4 stored in the sample container 3, and a liquid surface 41 of the sample 4.

[0032] Image (c) is an image of the sample container 3 taken at time t0 when the sample rack 2 being transported stops. Image (a) is an image of the sample container 3 taken at a time (t0-2Δt) 2Δt before time t0. Image (d) is an image of the sample container 3 taken at a time (t0+Δt) Δt after time t0, and image (g) is an image of the sample container 3 taken at a time (t0+4Δt) 4Δt after time t0.

[0033] 4 is a diagram showing an example of the change over time in the transport speed V of the sample rack 2. The time t in FIG. 4 indicates the time at which the image of the sample container 3 shown in FIG.

[0034] The captured images (a) and (b) shown in Figure 3 are captured at times (t0-2Δt) and (t0-Δt) in Figure 4, i.e., when the sample rack 2 is moving while decelerating. The sample containers 3 and the samples 4 therein continue to move.

[0035] Image (c) is an image captured at time t0 in Figure 4, i.e., when the sample rack 2 stops moving. At time t0, the sample rack 2 stops moving, but the liquid surface 41 of the sample 4, which is the free surface, is vibrating as shown in image (c) due to the inertial force acting on the sample 4 inside the sample container 3. The sample container 3 is also vibrating due to the support rigidity of the sample rack 2 and the inertial force.

[0036] 4, from time (t0+Δt) to time (t0+3Δt), i.e., when the sample rack 2 has completely stopped. At these times, the sample container 3 is almost stationary, but the liquid surface 41 of the sample 4 continues to sway as shown in images (d) to (f).

[0037] The captured images (g) to (i) are captured from time (t0+4Δt) to time (t0+6Δt) in Figure 4 (however, time (t0+5Δt) and time (t0+6Δt) are not shown in Figure 4). At these times, more time has passed since the captured image (f), the specimen container 3 is stationary, and the liquid surface 41 of the specimen 4 is barely moving, with the shaking having attenuated and become smaller.

[0038] In this embodiment, the control unit 10 detects the position of the liquid level 41 using the three captured images (d), (e), and (f) shown in Fig. 3. That is, the control unit 10 detects the position of the liquid level 41 using three captured images captured during the period from the time t0 when the sample rack 2 stops, which is a time Δt after the time t0, to the time 3Δt after the time t0.

[0039] A specific method for detecting the position of the liquid surface 41 will be described.

[0040] The control unit 10 creates two difference images between the images captured at two consecutive times from three captured images. In this embodiment, the control unit 10 creates a difference image A between the captured images (d) and (e) and a difference image B between the captured images (e) and (f) from three captured images (d), (e), and (f). The set of imaging times of the captured images from which the difference image A was obtained is different from the set of imaging times of the captured images from which the difference image B was obtained.

[0041] The control unit 10 detects the area with the largest area among the areas in the difference image that change over time as the position of the liquid surface 41 of the specimen 4. In this embodiment, the control unit 10 specifically detects the position of the liquid surface 41 as follows.

[0042] The control unit 10 creates an image (hereinafter referred to as an "inter-image difference image") by performing a binarization process on the logical product image of the two difference images. In this embodiment, the control unit 10 obtains the logical product image of difference image A and difference image B, and performs a binarization process on this logical product image to create an inter-image difference image. By performing a binarization process on the logical product image of the two difference images, the control unit 10 displays areas where the difference between the two difference images is small (i.e., areas where there is little change over time) in black, and areas where the difference between the two difference images is large (i.e., areas where there is a large change over time) in white. An area where the difference between the two difference images is large is an area where the difference in pixel brightness between the two difference images (i.e., the change in brightness over time) is larger than a predetermined threshold. This predetermined threshold can be determined arbitrarily in advance.

[0043] Therefore, in the inter-image difference image, areas in the three captured images where time change is small are displayed in black, and areas where time change is large are displayed in white. Hereinafter, areas in the inter-image difference image where time change is large (i.e., areas displayed in white) will be referred to as "change areas." An inter-image difference image may have multiple change areas.

[0044] The control unit 10 detects the change region with the largest area in the created inter-image difference image as the position of the liquid surface 41 of the specimen 4. The change region is a region where the difference between the difference images is large, i.e., a region where the change over time is large, and therefore represents a region that is moving in the captured image. The change region in the inter-image difference image obtained from the captured images (d), (e), and (f) is the liquid surface 41 of the specimen 4. The control unit 10 performs binarization processing to create the inter-image difference image, thereby more reliably and accurately detecting the region where the change over time is large, i.e., the liquid surface 41 of the specimen 4.

[0045] The key points of the liquid level detection method according to this embodiment are (1) to create a state in which the sample rack 2 is stopped and the sample container 3 is almost stationary, while only the liquid level 41 of the sample 4 is moving (the state of the captured images (d) to (f) in Figure 3), and (2) to create a differential image of the captured images using multiple captured images captured during the state of (1).

[0046] For (1), the control unit 10 stops the sample rack 2 being transported on the rack transport path 141. Next, the camera 5 starts capturing images of the sample containers 3 at least a time interval Δt after the sample rack 2 has stopped. This is because the sample containers 3 are likely not stationary due to the support rigidity of the sample rack 2 until the time interval Δt has elapsed since the sample rack 2 stopped. For (2), the camera 5 captures images of the sample containers 3 multiple times before the vibrations of the liquid surface 41 of the samples 4 dampen and come to a standstill.

[0047] The effect of the liquid level detection method according to this embodiment will be described with reference to FIGS. 5A, 5B, and 5C.

[0048] 5A, 5B, and 5C are schematic diagrams showing examples of inter-image difference images 50. These inter-image difference images 50 were created by creating two difference images using the three captured images captured at consecutive times shown in FIG. 3, and then performing binarization processing on the logical product image of these two difference images. FIG. 5A is an example of an inter-image difference image 50 created using the three captured images, captured images (a) to (c), shown in FIG. 3. FIG. 5B is an example of an inter-image difference image 50 created using the three captured images, captured images (d) to (f), shown in FIG. 3. FIG. 5C is an example of an inter-image difference image 50 created using the three captured images, captured images (g) to (i), shown in FIG. 3.

[0049] As described above, in the inter-image difference image 50, areas in the three captured images that change significantly over time (i.e., moving areas) are shown in white, and areas in the three captured images that change little over time (i.e., stationary areas) are shown in black.

[0050] In the inter-image difference image 50 in Figure 5A, not only the liquid level 41 of the sample 4 but also the sample container 3 and sample rack 2 are moving, so the area where the sample container 3 and sample rack 2 exist in addition to the liquid level 41 is also shown in white as a changed area. Therefore, to detect the liquid level 41 from the inter-image difference image 50 in Figure 5A, unnecessary areas other than the area showing the liquid level 41 must be identified from the changed area and deleted.

[0051] In the inter-image difference image 50 of Figure 5C, the sample rack 2 and sample container 3 are stationary while the liquid surface 41 of the sample 4 is pulsating, so that only the area where the liquid surface 41 exists is displayed in white as a changed area. However, in the inter-image difference image 50 of Figure 5C, the pulsation of the liquid surface 41 is small, so the changed area is minute. Therefore, there is a possibility that a changed area detected as noise will be erroneously detected as the liquid surface 41, or that the area where the liquid surface 41 exists will be unable to be distinguished from areas other than the liquid surface 41. For this reason, it is difficult to reliably and accurately detect the liquid surface 41 from the inter-image difference image 50 of Figure 5C.

[0052] In the inter-image difference image 50 of Figure 5B, the sample rack 2 and the sample container 3 are stationary while the liquid surface 41 of the sample 4 continues to sway relatively significantly, so the area where the liquid surface 41, which is an area that changes significantly over time, exists is clearly detected as a changed area shown in white. Note that in addition to the liquid surface 41, the inter-image difference image 50 of Figure 5B also contains areas (changed areas) shown in white due to noise, etc. Therefore, the control unit 10 extracts the changed area with the largest area in the inter-image difference image 50 as the position of the liquid surface 41 of the sample 4.

[0053] In the above explanation, the control unit 10 detected the position of the liquid level 41 from three captured images, but the control unit 10 may also detect the position of the liquid level 41 from two or four or more captured images by using a differential image between two or four or more captured images.

[0054] The position of the liquid level 41 detected by the control unit 10 can be displayed together with the captured image of the specimen container 3 on a display device provided in the automatic analyzer 1 or a display device connected to the automatic analyzer 1.

[0055] As explained above, in the automatic analyzer and liquid level detection method according to this embodiment, the transport of the sample rack 2 is stopped, and while the transport of the sample rack 2 is stopped and the liquid level 41 of the sample 4 continues to sway, the sample container 3 is imaged multiple times to obtain captured images, and the position of the liquid level 41 of the sample 4 is detected based on an area in these captured images that changes over time. Yo Therefore, the position of the liquid surface 41 of the specimen 4 can be detected reliably and accurately.

[0056] Furthermore, in this embodiment, the lighting 6 is installed on the same side of the rack transport path 141 as the camera 5, and the lighting 6 can irradiate light onto the sample container 3, which is the subject of the camera 5. Therefore, when the liquid surface 41 of the sample 4 sways, the light reflected by the liquid surface 41 sparkles, and the control unit 10 can detect this sparkle as a changing area (an area with large temporal changes) in the captured image. Therefore, in the automatic analyzer and liquid level detection method according to this embodiment, by using the lighting 6, the position of the liquid surface 41 of the sample 4 can be detected more reliably and accurately even when the sample 4 has low saturation and high transparency. [Example]

[0057] An automatic analyzer 1 according to a second embodiment of the present invention will be described. The automatic analyzer 1 according to this embodiment detects the liquid level 41 of the sample 4 using the liquid level detection method described in the first embodiment. The automatic analyzer 1 according to this embodiment differs from the automatic analyzer 1 according to the first embodiment in that the sample supply unit 12 is equipped with a camera 5 and a light 6. The following mainly describes the differences between the automatic analyzer 1 according to this embodiment and the automatic analyzer 1 according to the first embodiment.

[0058] FIG. 6 is a top view showing an outline of the configuration of the sample supply unit 12 provided in the automatic analyzer 1 according to this embodiment.

[0059] The sample supply unit 12 is provided with a camera 5 and a light 6 on the side of the loading rack transport path 141. The camera 5 and the light 6 are installed on the same side of the rack transport path 141. The camera 5 and the light 6 are installed on the opposite side of the rack transport path 141 from the barcode reader 115, that is, at positions where the rack transport path 141 is sandwiched between the camera 5 and the barcode reader 115.

[0060] The sample containers 3 stored in the sample rack 2 contain samples 4. The sample containers 3 are provided with barcode labels 31 for sample identification. In this embodiment, the barcode labels 31 are attached to the sample containers 3. The barcode labels 31 are attached to a portion of the circumference of the sample containers 3.

[0061] The sample rack 2 placed on the loading rack transport path 141 of the transport unit 14 has one surface (back surface 213) facing the barcode reader 115 and the other surface (front surface 212) facing the camera 5 and the light 6.

[0062] Since the barcode label 31 is attached to a part of the circumference of the sample container 3, the camera 5 can capture an image of the sample 4 contained in the sample container 3 from the front surface 212 of the sample rack 2.

[0063] The barcode reader 115 reads the barcode label 31 of the sample container 3 of the sample rack 2 that has been transported to the barcode reading position 116 on the rack transport path 141 .

[0064] Remove sample container 3 from sample rack 2. Without A slit 211 is provided on the rear surface 213 of the sample rack 2 so that the barcode reader 115 can read the barcode label 31 of the sample container 3. The barcode label 31 of the sample container 3 is aligned so that it faces the rear surface 213 of the sample rack 2.

[0065] The sample supply unit 12 is controlled by the control unit 10 to move the sample racks 2 placed at the entrance 123 of the sample rack 2 one by one to the rack transport path 141. The control unit 10 transports the sample racks 2 that have been moved to the rack transport path 141 to the focal position 7 of the camera 5 and the barcode reading position 116, respectively.

[0066] At the focal position 7 of the camera 5, the front surface 212 of the sample rack 2 becomes the imaging plane of the camera 5. At the focal position 7, the camera 5 captures an image of the sample container 3 and the sample 4 contained in the sample container 3. Because the barcode label 31 is affixed to a portion of the circumference of the sample container 3, the control unit 10 can detect the position of the liquid surface 41 of the sample 4 from the image captured by the camera 5 of the sample container 3 without being obstructed by the barcode label 31.

[0067] At the barcode reading position 116, the rear surface 213 of the sample rack 2 becomes the scan surface of the barcode reader 115. The barcode reader 115 reads the barcode label 31 affixed to the sample container 3 at the barcode reading position 116. The control unit 10 can identify the sample 4 contained in the sample container 3 based on the information obtained from the barcode label 31 read by the barcode reader 115. After identifying the sample 4, the sample supplying unit 12, under the control of the control unit 10, assigns a destination analysis module 13 to the sample rack 2 in accordance with pre-registered item information, and transports the sample rack 2 to the loading rack transport path 141 of the transport unit 14.

[0068] In the automatic analyzer 1 according to this embodiment, the barcode reader 115 is installed on one side of the loading rack transport path 141, and the camera 5 is installed on the other side of the rack transport path 141. This allows the control unit 10 to capture images of the sample containers 3 stored in the sample rack 2 on the rack transport path 141 and read the barcode labels 31 affixed to the sample containers 3 without changing the orientation of the sample containers 3. In this embodiment, since it is possible to read the barcode labels 31 and capture images of the sample containers 3 without changing the orientation of the sample containers 3, a decrease in the throughput of the automatic analyzer 1 can be prevented and a mechanism for changing the orientation of the sample containers 3 is not required.

[0069] Furthermore, in this embodiment, the focal position 7 of the camera 5 and the barcode reading position 116 may be aligned so that the operation of capturing an image of the sample container 3 and the operation of reading the barcode label 31 can be performed at one location. In this way, both the image of the sample container 3 and the reading of the barcode label 31 can be performed at one position where the sample rack 2 is stopped, which reduces the number of times the sample rack 2 is stopped, preventing a decrease in the throughput of the automatic analyzer 1.

[0070] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to embodiments including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete part of the configuration of each embodiment, or to add or replace other configurations. [Explanation of symbols]

[0071] 1...automated analyzer, 2...sample rack, 2a...multiple-sample rack, 2b...single-sample rack, 3...sample container, 4...sample, 5...camera, 6...lighting, 7...focus position, 10...control unit, 12...sample supply unit, 13...analysis module, 14...transport unit, 31...barcode label, 41...liquid level, 50...image difference image, 115...barcode reader, 116...barcode reading position, 123...inlet, 124...outlet, 126...barcode reading position, 141...inlet rack transport path, 142...outlet rack transport path, 211...slit, 212...front of sample rack, 213...rear of sample rack, C...center axis of sample container, D...arrow indicating sample rack transport direction, p...pitch, t...time, t0...time when sample rack stops, Δt...imaging time interval, V...transport speed.

Claims

1. a rack transport path for transporting a sample rack containing sample containers containing samples; a camera provided on the side of the rack transport path; a control unit that controls the rack transport path and the camera; Equipped with The control unit Stopping the transport of the sample rack being transported by the rack transport path; The sample containers stored in the sample rack during the stopped transfer are imaged multiple times with the camera while the liquid surface of the sample continues to sway, thereby obtaining multiple images of the sample containers while the liquid surface of the sample continues to sway; creating a difference image of a plurality of the captured images at successive times among the plurality of times at which the captured images were acquired; a region having a maximum area among regions in one of the difference images that show a time change is detected as the position of the liquid surface of the sample; An automatic analyzer characterized by:

2. A rack transport path for transporting a sample rack containing sample containers containing samples; a camera provided on the side of the rack transport path; a control unit that controls the rack transport path and the camera; Equipped with The control unit Stopping the transport of the sample rack being transported by the rack transport path; The sample containers stored in the sample rack during the stopped transfer are imaged multiple times with the camera while the liquid surface of the sample continues to sway, thereby obtaining multiple images of the sample containers while the liquid surface of the sample continues to sway; creating a difference image of a plurality of the captured images at successive times among the plurality of times at which the captured images were acquired; a logical product image is obtained from the plurality of difference images, and a region having a maximum area among regions in the logical product image that change over time is detected as the position of the liquid surface of the sample; An automatic analyzer characterized by:

3. the control unit performs a binarization process on the logical product image, and determines the area with the largest area among areas in which time change occurs in the image created by performing the binarization process as the position of the liquid surface of the sample. The automatic analyzer according to claim 2 .

4. a light provided beside the rack transport path on the same side as the camera with respect to the rack transport path; The illumination irradiates the specimen container with light. The automatic analyzer according to claim 1 .

5. a barcode reader for reading a barcode label attached to the sample container; the barcode reader is installed on the opposite side of the rack transport path from the camera, The focal position of the camera coincides with the position where the barcode reader reads the barcode label. The automatic analyzer according to claim 1 .

6. transporting a sample rack containing sample containers containing samples along a rack transport path; stopping the transport of the sample rack being transported by the rack transport path; capturing images of the sample containers stored in the sample rack during which transport is stopped, multiple times with a camera while the liquid surface of the sample continues to sway, thereby obtaining multiple images of the sample containers while the liquid surface of the sample continues to sway; creating a difference image of a plurality of the captured images at successive times among the plurality of times at which the captured images were acquired; detecting a region having a maximum area among regions in one of the subtraction images that change over time as the position of the liquid surface of the sample; A liquid level detection method comprising:

Images