JP7603286B2 - Device for determining agglutination in blood samples - Google Patents

Description

The present invention relates to a blood sample agglutination determination device that captures an image of a blood sample container that contains a blood sample and determines whether agglutination has occurred in the blood sample container based on the captured image.

Blood samples used in clinical testing are collected in dedicated containers and subjected to blood testing. A blood analyzer that automatically analyzes blood components is configured to aspirate a portion of the blood sample from the blood sample container using an aspirating tube and analyze the aspirated blood via a flow path.
For this reason, if agglutinates are present in a blood sample, the agglutinates may be sucked into the blood analyzer when the blood sample is sucked into the suction tube, causing the suction state to become unstable, and in some cases, this may lead to serious problems such as the agglutinates clogging the suction tube or flow path, causing the analysis to stop. When this happens, the blood analyzer must be disassembled and cleaned, or parts must be replaced.
In order to prevent the above problems, screening is required to check for the presence of agglutinates when blood is collected, and to prevent blood samples containing agglutinates from being input into an analytical device.
Conventionally, this screening has been performed manually and visually by an engineer, but an apparatus that automates this process has been proposed (Patent Document 1).

Patent No. 3957864

The device according to the above-mentioned Patent Document 1 is configured to image the blood sample in a test tube from which blood has been collected in a first state, then move the test tube to a second state, and then image the blood sample in the test tube in the second state, binarize each of the captured images to calculate the area of each image, subtract the area of the image in the second state from the area of the image in the first state, and compare the result with a predetermined reference value to determine whether or not the blood has coagulated.
However, in the conventional devices described above, the distribution of illumination when imaging the blood sample itself remains as an error factor for the binarization threshold, such as the center of the illumination being bright and the periphery being dark, resulting in a decrease in judgment accuracy and preventing the device from fully demonstrating its effectiveness.
In addition, in clinical settings, blood samples are required to be stirred and mixed with reagents such as anticoagulants and glycolysis inhibitors that have been sealed in the sample container beforehand immediately after collection. However, sufficient stirring and mixing may not be achieved, and depending on the blood properties, this may cause the formation of aggregates.
The present invention aims to solve the above-mentioned conventional problems, and to provide an apparatus for determining agglutinates in a blood sample, which can sufficiently stir and mix a blood sample storage container in which a blood sample has been collected, and can accurately determine the presence or absence of agglutinates.

In order to achieve the above-mentioned object, the device for determining aggregates in a blood sample according to the present invention comprises a drive unit that holds a specimen container in which a blood sample has been collected, and rotates the specimen container circumferentially in one direction and in the opposite direction about its longitudinal axis, while alternately rotating the specimen container radially in one direction and in the opposite direction at a constant rotation angle about an approximate longitudinal center position of the specimen container, an imaging means provided in the drive unit that moves in accordance with the radial rotation of the specimen container by the drive unit and captures fixed-point images of a predetermined imaging area of the specimen container, and a control device that controls the operation of the drive unit and the imaging means, wherein the control device is configured to form a coating film of the blood specimen on the inner surface of the specimen container by the circumferential and radial rotation of the specimen container by the drive unit, continuously capture images of the coating film by the imaging means, image process the obtained images by spatial filtering the luminance distribution, and determine the presence or absence of aggregates based on the image data after image processing.
The drive unit may comprise a radial rotation drive unit that rotates the specimen container radially in one direction and the other at a constant rotation angle around approximately the center position of the specimen container in the longitudinal direction, and moves the bottom of the specimen container back and forth between the top and bottom positions, and a circumferential rotation drive unit that rotates the specimen container circumferentially around its longitudinal axis, and the circumferential rotation drive unit may be configured to operate in conjunction with the movement of the radial rotation drive unit.
In addition, the radial rotation drive unit may have a drive shaft driven by a motor and a pair of driven rollers rotatably held on the drive shaft, and the circumferential rotation drive unit may have a circumferential drive roller provided on the drive shaft and rotates circumferentially due to the rotational motion of the drive shaft, and the sample container may be configured to be supported at three points by the driven rollers and the circumferential drive rollers.
In this case, the circumferential rotation drive unit may have a rubber-lined roller that rotates on its own axis and moves in a circle around the axis of the drive shaft due to the rotational motion of the drive shaft, and a power transmission means that transmits the rotation of the rubber-lined roller to the drive shaft of the circumferential drive roller, and may be configured so that while the sample container rotates radially due to the rotation of the drive shaft, the sample container rotates circumferentially due to the rotation of the rubber-lined roller.
The rotation drive unit may have a rubber-lined roller that rotates circumferentially and moves in a circle around the axis of the drive shaft due to the rotational motion of the drive shaft, and a power transmission means that transmits the circumferential rotation of the rubber-lined roller to the rotation drive shaft of the circumferential drive roller, and may be configured so that while the sample container rotates due to the rotation of the drive shaft, the sample container rotates circumferentially due to the circumferential rotation of the rubber-lined roller.
The control device may control the motor to rotate the drive shaft forward and reverse at a constant speed, and may also control the motor to reduce the rotational speed of the drive shaft when the bottom of the sample container is between the uppermost and lowermost positions.

The blood sample aggregate determination device according to the present invention comprises a drive unit that holds a sample container in which a blood sample has been collected, and rotates the sample container circumferentially in one direction and in the opposite direction about its longitudinal axis while alternately rotating the sample container radially in one direction and in the opposite direction at a constant rotation angle about its approximate longitudinal center position, an imaging means provided in the drive unit that moves in accordance with the radial rotation of the sample container by the drive unit and captures a fixed-point image of a predetermined imaging area of the sample container, and a control device that controls the operation of the drive unit and the imaging means, and the control device forms a coating of the blood sample on the inner surface of the sample container by the circumferential and radial rotation of the sample container by the drive unit, and transfers the coating to the imaging means. The system is configured to capture images continuously in stages, process the resulting images by spatially filtering the luminance distribution, and determine the presence or absence of aggregates based on the image data after image processing. This allows a coating of the blood sample to be formed on the inner surface of the sample container while reproducing the manual stirring and mixing of the sample container by a technician, and the images obtained by capturing the coating are processed by spatially filtering the luminance distribution, making it possible to accurately determine the presence or absence of aggregates without depending on the amount of sample or the sample's prior stirring and mixing state, and without depending on the surrounding lighting, which can be a source of error for the binarization threshold.

FIG. 1 is a diagram illustrating a method for visually checking aggregates by a technician. 5A to 5C are diagrams illustrating the movement of a sample container in the agglutination-detecting device according to the present invention. 1 is a schematic top view of an aggregate determination device according to the present invention. FIG. 4 is a schematic front view of the aggregate determination device shown in FIG. 3 . 4 is a schematic side view of the aggregate-detecting device shown in FIG. 3 as viewed from the rotation drive unit side. FIG. 10A and 10B are diagrams illustrating the operation of a sample container moved by the agglutination-determining device. 13A and 13B are diagrams showing images captured by a camera at the topmost position, the bottommost position, and an intermediate position between the topmost and bottommost positions during a twisting rotation operation of the sample container in which the bottom of the container sample is rotated from the bottommost position to the topmost position. FIG. 2 is a schematic block diagram of a control device. 1A and 1B are diagrams showing an example of an original image captured by a camera and a detected image obtained by performing spatial filtering on the original image; 4 is a flowchart illustrating a control flow by the control device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an apparatus for determining aggregates in a blood sample according to the present invention (hereinafter simply referred to as "aggregate determining apparatus") will be described below with reference to one embodiment shown in the accompanying drawings.
First, a method for visually checking for aggregates by an engineer will be briefly described with reference to FIG.
When a technician manually checks for agglutinations in a blood sample, as shown in Figure 1, he holds the lid of the sample container in which the blood sample has been collected, shakes the sample container up and down so that the lid side and the bottom side are reversed, and when the bottom of the sample container is at the upper limit position, he visually inspects the bottom of the sample container while twisting the sample container with his fingertips to check for the presence or absence of agglutinations. Also, when the bottom of the sample container is at the lower limit position, he twists the sample container back in the opposite direction with his fingertips to prepare for the next twist at the upper limit position. When the sample container is at a position other than the upper limit or lower limit position, he monitors the flow of the blood sample in the sample container. This process is repeated several times.
As described above, when a technician manually checks for agglutinations in a blood sample, the technician does not simply shake the sample container up and down, but rather shakes the sample container up and down while twisting it. This allows sufficient stirring and mixing, and the blood sample in the sample container flows along the inner surface of the sample container, making it easier to visually check for agglutinations.
The agglutination determination device of the present invention is configured to be able to determine the presence or absence of agglutinations in a blood sample in a sample container while realizing the behavior of the sample container due to the above-mentioned technician's manual technique with a simple structure.

First, as shown in FIG. 2, the agglutination determination device according to the present invention is a device configured to determine the presence or absence of agglutinations in a blood sample in a sample container based on information obtained in the process of rotating a sample container in one direction and in the other direction around its longitudinal axis while rotating it in one direction and in the other direction at a fixed angle around approximately the longitudinal center position.
In this specification,
The rotational movement of the sample container in one direction and in the other direction about its longitudinal axis is called "circumferential rotation";
The rotational movement of the sample container in one direction and the other direction around its approximate center in the longitudinal direction is referred to as "radial rotation."
Hereinafter, the configuration of one embodiment of the aggregate-detecting device according to the present invention will be described with reference to FIGS.
FIG. 3 is a schematic top view of the agglomerate-detecting device, FIG. 4 is a schematic front view of the agglomerate-detecting device shown in FIG. 3, and FIG. 5 is a schematic side view of the agglomerate-detecting device as viewed from the rotation drive unit side.
In the figure, the symbol 1 indicates a frame, and fixed to the frame 1 are a radial rotation drive unit 2 that rotates the specimen container alternately in one direction and the other direction at a constant rotation angle around approximately the center position in the longitudinal direction, i.e., rotates the specimen container radially, and a motor 3 that operates the radial rotation drive unit 2.
The radial rotation drive unit 2 includes a drive shaft 7 whose one end is rotated by a motor 2 via pulleys 4 and 5 and a belt 6, and a pair of driven rollers 8 and 9 for holding sample containers which are rotatably fixed to the tip of the drive shaft 7 via a bracket (not numbered).
The drive shaft 7 of the radial rotation drive unit 2 is provided with a circumferential rotation drive unit 10 for rotating the specimen container in one direction and in the other direction around its central axis so as to apply a twisting motion to the specimen container, i.e., for rotating the specimen container in a circumferential direction. The circumferential rotation drive unit 10 is provided on the drive shaft 7 via a bracket (no reference number) and includes a rubber-lined roller 11 that performs a circular motion around the central axis of the drive shaft 7 as the drive shaft 7 rotates. The circumferential rotation drive unit 10 includes a drive shaft 12 for rotating the specimen container in a circumferential direction, a pair of pulleys 13 and 14 that transmit the rotation generated during the circular motion of the rubber-lined roller 11 to the drive shaft 12, an idle roller 15, and a belt 16, and a circumferential drive roller 17 is provided at the tip of the drive shaft 12.
The specimen container is held at three points by the driven rollers 8 and 9 and the circumferential drive roller 17, and rotates in the circumferential direction by the rotation of the circumferential drive roller 17.
5, the rubber-lined roller 11 is provided on a sliding plate 18, and is pressed by a spring 19 against a guide frame 20 through which the drive shaft 7 of the radial rotation drive unit 2 penetrates, so that the roller 11 rotates due to friction with the guide frame 20 when it makes a circular motion on the guide frame 20 as the drive shaft 7 of the radial rotation drive unit 2 rotates. Also, as shown in FIG. 5, the idle roller 15 is configured to apply tension to the belt 16 by a spring 21.
Furthermore, a camera 22 is provided on the drive shaft 7 of the radial rotation drive unit 2 configured as described above, which rotates together with the radial rotation drive unit 2 and continuously captures an image of the vicinity of the bottom of the specimen container held during operation at a fixed point. In Fig. 4, the symbol A indicates an imaging area captured by the camera 22. The camera 22 is positioned so that its imaging area views an area closest to the bottom of the cylindrical portion of the specimen container, thereby making it possible to reliably capture an image of the blood specimen in the specimen container without being restricted by the size of the lid of the specimen container or by labels or direct printing attached to the specimen container.
As shown in FIG. 4, a sensor 23 for detecting the presence or absence of a specimen container is provided at a position where the specimen container is supported at three points by the pair of driven rollers 8 and 9 and the circumferential drive roller 17, and the output of the sensor is used to detect whether the specimen container has been inserted correctly.
The motor 3 is preferably a stepping motor that can easily control the rotation direction (ie, clockwise and counterclockwise) as well as the speed and position by numerical values.
The agglutination determination device configured as described above further includes a control device 24, which controls the operation of the motor 3 and the camera 22, and is configured to be able to determine the presence or absence of agglutinations in the blood sample in the specimen solution based on image data input from the camera 22.

Next, the mechanical operation of the agglutinate-detecting device configured as above will be described.
In the above-described agglomerate determination device, the operations of the motor 3 and the camera 22 are controlled by the control device 24 .
The motor 3 drives the drive shaft 7 so as to rotate the container specimen alternately in one direction and the other direction by a fixed rotation angle, for example, 45 degrees, about its longitudinal center, i.e., so as to rotate radially. When the drive shaft 7 rotates, the specimen container supported at three points by the driven rollers 8 and 9 provided on the drive shaft 7 and the circumferential drive roller 17 provided on the drive shaft 12 of the circumferential rotation drive unit 10 rotates radially in one direction or the other direction.
As the drive shaft 7 rotates, a rubber-lined roller 11 of a circumferential rotation drive unit 10 provided on the drive shaft 7 makes a circular motion on a guide frame 20 around the axis of the drive shaft 7, and during this circular motion, the rubber-lined roller 11 rotates due to friction with the guide frame 20. The rotation of the rubber-lined roller 11 is transmitted to the drive shaft 12 via pulleys 13 and 14, an idle roller 15, and a belt 16, and the drive shaft 12 is driven to rotate together with the circumferential drive roller 17. The circumferential drive roller 17 supports the sample container at three points and is in contact with the sample container, so that as the circumferential drive roller 17 rotates, the sample container rotates in one direction or the other around its longitudinal axis.
Therefore, when the drive shaft 7 is rotated in one direction by a fixed rotation angle by the motor 3, the sample container rotates circumferentially in one direction around its longitudinal axis while also rotating radially in one direction around its approximate longitudinal center position.
After the sample container has been rotated to a predetermined angle, when the motor 3 is rotated in the reverse direction, the sample container rotates in the radial direction in the reverse direction while rotating in the circumferential direction in the reverse direction.
This operation of rotating the sample container in the radial direction while rotating in the circumferential direction is called a "torsional rotation operation."
This movement of the sample container corresponds to the manual movement of a technician twisting the sample container and shaking it up and down, and thus the sample container moves in the same manner as the technician's manual movement.
FIG. 6 is a diagram showing a schematic diagram of the operation of a sample container moved by the agglutination-determining device.
The number of rotations in the circumferential direction during the radial rotation of the sample container in the above description can be calculated using Equations 1 and 2.
Number of rotations of the sample container in the circumferential direction = length of the path of one stroke of the rubber-lined roller ÷ circumferential length of the rubber-lined roller: Formula 1
Here, the path length of one stroke of the rubber-lined roller is given by the following formula 2.
Path length of one stroke of rubber-lined roller = rotation diameter R of rubber-lined roller x pi x rotation angle θ ÷ 360 degrees: Formula 2
Therefore, if the diameters of the pulleys 13 and 14 of the circumferential rotation drive unit 10 are made the same, the number of rotations of the rubber-lined roller 11 and the number of rotations of the circumferential drive roller 17 will be the same, and if the diameter of the rubber-lined roller 11 is, for example, 20φ, the rubber-lined roller rotation diameter R is 60 mm, and the rotation angle θ is 90°, the circumferential drive roller 17 will make 1.5 rotations, and by making the diameter of the circumferential drive roller 17 approximately the same as the diameter of the specimen container, the specimen container will also make 1.5 rotations. In reality, there is some slippage, so the number of rotations is less than 1.5, but this is necessary and sufficient rotation from the perspective of a camera capturing an image at a fixed position.
The radial rotation drive unit 2 and the circumferential rotation drive unit 10 perform the twisting and rotating operation of the sample container a predetermined number of times.
During the twisting and rotating operation of the specimen container described above, the camera 22 images the imaging area A at the top position where the bottom of the specimen container is at the top and at the bottom position where the bottom of the specimen container is at the bottom, and at the same time, continuously images the imaging area A while the bottom of the specimen container is moving from the top position to the bottom position or from the bottom position to the top position.
7 shows images captured by the camera 22 at the top position, the bottom position, and an intermediate position between the top and bottom positions during the twisting and rotating operation of the specimen container in which the bottom of the container specimen is rotated from the bottom position to the top position. Note that the intermediate position is any position between the top and bottom positions, and although three images are displayed in FIG. 7, this does not represent the number of times images are taken by the camera 22, but represents three images taken consecutively.
The images shown in FIG. 7 are images of a blood sample containing no aggregates. As shown in this figure, in the case of a blood sample containing no aggregates, the image captured at the top position is the lightest in color, the image captured at the bottom position is the darkest in color, and the image captured at the intermediate position is a beautiful gradation image.
In addition, in the radial rotation direction of the specimen container illustrated in Fig. 7, when the specimen container passes the intermediate position, it rotates in the circumferential direction around its longitudinal center. Specifically, the specimen container rotates in the circumferential direction in the direction in which the imaging side of the specimen container rises when viewed from the camera 22, so that the wet surface of the specimen inner surface with the blood specimen rises in the specimen container, and the blood specimen is evenly applied to the inner surface of the specimen container. As a result, even when the amount of blood specimen is small, the blood specimen is evenly applied to the inner surface of the specimen container due to the circumferential rotation of the specimen container, making it possible to distinguish agglutinations. The state in which the inner surface of the specimen container is wetted with the blood specimen due to this rising corresponds to the state in Fig. 1 when the technician visually inspects the specimen container while twisting it manually.
The image captured by the camera 22 is sent to the control device 24 .
The aggregate detection device configured as described above further includes an illumination means (not shown). The illumination means includes indirect white light illumination provided at a plurality of locations, and is configured to reduce shadows in the imaging area of the specimen container when the camera 22 captures an image.
Figure 8 is a schematic block diagram of the control device 24. As shown in the figure, the control device 24 is equipped with a memory 23a, a CPU 23b and a GPU (graphics processing unit) 23c, and is connected to the motor 3, the camera 22 and the sensor 23. When the insertion of a specimen container is detected based on a signal from the sensor 23, the control device 24 controls the drive of the motor 3, and performs image processing on the input image from the camera 22 to determine the presence or absence of an aggregate.
Specifically, the image captured by the camera 22 is stored in the memory 24a, and the GPU 24c converts the RGB image into YUV data (a combination of three data: a luminance signal (Y), a difference between the luminance signal and a blue component (U), and a difference between the luminance signal and a red component (V)). The Y value, which is the luminance information, is used to extract intermediate frequency components by spatial filtering, thereby removing low frequency components in the gradation area without aggregates and high frequency components such as noise, thereby making the aggregates stand out. FIG. 9 shows an example of a detection image obtained by spatial filtering from the original image captured by the camera 22. The CPU 24b judges the presence or absence of aggregates based on the image processed by the GPU 24c using a program stored in advance. Specifically, for example, a differential filter (edge detection process) is used to find the amount of change in the shade that stands out, and the CPU 24b judges a peak value that exceeds a value previously set for the amount of change in shade to be an aggregate based on the image processed by the GPU 24c. The method of judging an aggregate based on this image processing is not limited to this embodiment, and various known judgment methods can be used.

FIG. 10 is a flow chart that shows the flow of control by the control device 24 configured as described above.
The control device 24 is registered in advance as to whether or not the specimen container to be processed needs to be pre-mixed, and the number of images to be captured during one operation by the camera 22 (for example, one operation is defined as a twisting and rotating operation in which the bottom of the specimen container goes back and forth from the top position to the bottom position) and the number of operations for the specimen container are set.
The process waits until the sensor 23 detects that the specimen container has been inserted and supported at three points by the three rollers 8, 9 and 17 (step 1).
Whether or not pre-mixing is necessary is determined based on previously registered information (step 2), and if pre-mixing is necessary, the motor 3 is operated to perform a predetermined number of twisting and rotating operations of the specimen container without capturing an image with the camera 22 (step 3).
Next, a trigger timer is set to start imaging by the camera 22, and the specimen container is twisted and rotated by the motor 3 (step 4). During this twisting and rotating operation, imaging by the camera 22 is repeated a preset number of times, and the camera 22 sends the captured image to the control device 24, which processes the image input from the camera 22 (YUB conversion and spatial filtering) (step 5), and determines the presence or absence of aggregates from the obtained image (step 6).
If an aggregate is detected in the judgment in step 6, the motor 3 and camera 22 are stopped and the detection result is displayed (step 8), and after the removal of the specimen container is detected (step 9), the process returns to waiting until the next specimen container is inserted (step 1).
If no agglutinates are detected in the determination in step 6, the processes in steps 4 to 6 are repeated until a predetermined number of operations is reached (step 7), and when the predetermined number of operations is reached, the detection result is displayed (step 8). After detecting the removal of the specimen container (step 9), the process returns to waiting for the next specimen container to be inserted (step 1).
The control of the motor 3 by the control device 24 may be executed so as to rotate the drive shaft 7 forward and backward at a constant speed, but may also be configured so as to reduce the speed when the bottom of the specimen container passes an intermediate position between the uppermost position and the lowermost position. By reducing the speed at the intermediate position in this manner, it becomes possible to increase the number of times images are taken at the intermediate position.

REFERENCE SIGNS LIST 1 Frame 2 Radial rotation drive section 3 Motor 4 Pulley 5 Pulley 6 Belt 7 Drive shaft 8 Driven roller 9 Driven roller 10 Circumferential rotation drive section 11 Rubber-lined roller 12 Drive shaft 13 Pulley 14 Pulley 15 Idle roller 16 Belt 17 Circumferential drive roller 18 Slide plate 19 Spring 20 Guide frame 21 Spring 22 Camera 23 Sensor 24 Control device

Claims (6)

a drive unit (2, 10) that holds a specimen container in which a blood specimen has been collected, and rotates the specimen container in a circumferential direction in one direction and in a reverse direction about its longitudinal axis while rotating the specimen container in a radial direction alternately in one direction and in a reverse direction at a constant rotation angle about an approximate longitudinal center position of the specimen container;
an imaging means (22) provided in the driving unit (2, 10) that moves following the radial rotation of the specimen container by the driving unit (2, 10) and captures a fixed-point image of a predetermined imaging area of the specimen container; and a control device (24) that controls the operation of the driving unit (2, 10) and the imaging means (22),
The control device (24)
forming a coating film of the blood sample on the inner surface of the sample container by rotating the sample container in the circumferential direction and the radial direction by the drive unit (2, 10), and continuously capturing images of the coating film by the imaging means (22);
The obtained image is processed by spatially filtering the brightness distribution.
An apparatus for determining whether or not an aggregate is present in a blood sample, the apparatus being configured to determine whether or not an aggregate is present based on image data after image processing. The drive unit (2, 10)
a radial rotation drive unit (2) for rotating the specimen container radially in one direction and the other direction at a fixed rotation angle about an approximate center position in the longitudinal direction of the specimen container, thereby reciprocating the bottom of the specimen container between an uppermost position and a lowermost position;
a circumferential rotation drive unit (10) for rotating the sample container in a circumferential direction about its longitudinal axis;
The agglomerate determination device according to claim 1, characterized in that the circumferential rotation drive unit (10) is configured to operate in conjunction with the movement of the radial rotation drive unit (2). The radial rotation drive unit (2) includes a drive shaft (7) driven by a motor (3) and a pair of driven rollers (8, 9) rotatably held on the drive shaft (7),
The circumferential rotation drive unit (10) includes a circumferential drive roller (17) that is provided on the drive shaft (7) and rotates in a circumferential direction by the rotational motion of the drive shaft (7),
3. The agglutination determining device according to claim 2, wherein the sample container is supported at three points by the driven rollers (8, 9) and the circumferential drive roller (17). The circumferential rotation drive unit (10) includes a rubber-lined roller (11) that rotates and moves circularly about the axis of the drive shaft (7) due to the rotational motion of the drive shaft (7),
and a power transmission means (13, 14, 15, 16) for transmitting the rotation of the rubber-lined roller (11) to the drive shaft (12) of the circumferential drive roller (17),
The agglutination determination device according to claim 3, characterized in that, while the sample container is rotated in a radial direction by the rotation of the drive shaft (7), the sample container is rotated in a circumferential direction by the rotation of the rubber-lined roller (11). The agglomerate determination device according to claim 3, wherein the control device (24) controls the motor (3) to rotate the drive shaft (7) forward and reverse at a constant speed. The agglutination determination device according to claim 3, characterized in that the control device (24) is configured to reduce the rotational speed of the drive shaft (7) when the bottom of the sample container is between the uppermost position and the lowermost position.

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