Automated analysis device

Abstract

To provide an automatic analysis device that can ensure a predetermined dispensing accuracy, is smaller and less expensive even if a degassing module is not provided, the following configuration is employed. The automatic analysis device includes a dispensing probe that dispenses a liquid, a syringe that generates a pressure for drawing the liquid into the dispensing probe, and a flow path that connects the dispensing probe and the syringe, the flow path being configured to pass through a position higher than the syringe, i.e., an A point, and a position lower than the dispensing probe, i.e., a B point, and to have a bubble retention portion for temporarily retaining a bubble generated in the syringe between the A point and the B point.

Description

Technical Field

[0001] This invention relates to an automatic analysis device. Background Technology

[0002] An automated analysis device refers to a device that reacts a sample, such as blood, with the target component and analytical reagents in the sample, analyzes the reaction using optical methods, and automatically outputs results from the detection of the target component. Such an automated analysis device includes a step of using a dispensing probe (also called a dispensing nozzle) to aspirate the sample.

[0003] The dispensing probe is connected to a pump, referred to as a syringe, via a flow path. By driving the syringe to create negative pressure within the flow path, liquid is drawn into the dispensing probe. Such a dispensing probe is constructed, for example, as described in Patent Document 1. Figure 2 .

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2020 / 066523 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] As in patent document 1 Figure 2 As described, the flow path between the dispensing probe and the syringe is typically connected to the syringe located within the analytical apparatus via the arm's rotation axis, which is used to move the dispensing probe up and down / rotate. The flow path is filled with water (also known as system water) as a pressure transmission medium. The movement of the system water within the flow path, caused by the syringe's action, generates negative / positive pressure within the dispensing nozzle at the probe tip, drawing / draining liquid into / out of the nozzle.

[0009] Since water is the pressure transmission medium in the system, the presence of air bubbles in the liquid temporarily disrupts these bubbles, causing them to act as a buffer and preventing proper control of the amount of liquid drawn into / out of the probe. Therefore, in typical automated analytical devices, pure water produced by a pure water generator is supplied to the probe flow path after air bubbles are removed by a degassing module (usually vacuum degassing).

[0010] However, the degassing module requires a vacuum pump, degassing piping, and other components, necessitating sufficient space within the automated analysis device. Therefore, it can become an obstacle to miniaturization, especially in small-scale devices. Furthermore, the added cost of the degassing module makes it difficult to apply to small, inexpensive automated analysis devices.

[0011] The purpose of this invention is to provide a small and inexpensive automatic analysis device that can ensure predetermined dispensing accuracy even without a degassing module.

[0012] Solution for solving the problem

[0013] The structure of the present invention for achieving the above objectives is as follows.

[0014] The automated analyzer includes: a dispensing probe for dispensing liquid; a syringe for generating pressure to draw liquid into the dispensing probe; and a flow path connecting the dispensing probe and the syringe. The flow path is configured to pass through a position higher than the syringe (point A) and a position lower than the dispensing probe (point B), with a bubble retention section between points A and B for temporarily retaining bubbles generated in the syringe.

[0015] Invention Effects

[0016] According to the present invention, a small and inexpensive automatic analysis device can be provided that can ensure a predetermined dispensing accuracy even without a degassing module. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the automatic analysis device.

[0018] Figure 2 This is a schematic diagram of the dispensing mechanism of the automatic analysis device.

[0019] Figure 3 This is a diagram showing the general structure of the flow path of the dispensing mechanism in an automatic analysis device.

[0020] Figure 4 It means to Figure 3 A diagram showing the pressure changes during continuous dispensing of liquid in the liquid dispensing mechanism.

[0021] Figure 5 This is a diagram showing the structure of the flow path of the liquid dispensing mechanism in Example 1.

[0022] Figure 6A This is an explanation Figure 5 A diagram showing the movement of bubbles in the flow path.

[0023] Figure 6B This is an explanation Figure 5 A diagram showing the movement of bubbles in the flow path.

[0024] Figure 7 It means to Figure 5 A diagram showing the pressure changes during continuous dispensing of liquid in the liquid dispensing mechanism.

[0025] Figure 8 This is a diagram showing the structure of the flow path of the liquid dispensing mechanism in Example 2.

[0026] Figure 9 This is a diagram showing the structure of the flow path of the liquid dispensing mechanism in Example 3.

[0027] Figure 10 This is a diagram showing the structure of the flow path of the liquid dispensing mechanism in Example 4.

[0028] Figure 11 This is a diagram showing the structure of the flow path of the liquid dispensing mechanism in Example 5. Detailed Implementation

[0029] The embodiments of the present invention are described below with reference to the accompanying drawings. Furthermore, the present invention is not limited to these embodiments.

[0030] Figure 1 This is an example of a structural diagram of an automatic analysis device.

[0031] The sample container 103 is arranged in a ring on the sample tray 102 inside the automatic analysis device 101. During sample dispensing, the tray rotates clockwise and counterclockwise, causing the sample container 103 to move toward the sample dispensing mechanism 104.

[0032] To simplify specimen management, a barcode for identification is sometimes affixed to the specimen container 103. The barcode records information related to the specimen ID, specimen type (serum, urine, etc.). The barcode on the specimen container 103 is read by a barcode reader 120.

[0033] The sample dispensing mechanism 104 consists of a rotary drive mechanism, an up-and-down drive mechanism, and a dispensing probe. It moves between the sample aspiration position and the sample discharge position via the rotary drive mechanism and the up-and-down drive mechanism.

[0034] The reagent storage tank 105 includes a reagent tray 106 and a reagent container holding section 107. Typically, the reagent storage tank has a cold preservation function to prevent reagent deterioration caused by changes over time. The reagent container holding section 107 is arranged in a double ring on the reagent tray 106, holding multiple reagent bottles. The reagent tray 106 has a rotation drive mechanism that moves each reagent bottle to a predetermined position on the circumference via rotational motion.

[0035] The reagent dispensing mechanism 108 consists of a rotary drive mechanism, an up-and-down drive mechanism, and a dispensing probe. The reagent dispensing mechanism rotates and descends towards the predetermined reagent bottle position on the reagent tray 106, attracting a predetermined amount of reagent. After the reagent is attracted, the dispensing mechanism rises. Then, it rotates and descends towards the reagent discharge destination (a predetermined reaction unit on the reaction tray 109) to discharge the reagent.

[0036] The biochemical analysis workflow is described in the order of processing (sample aliquoting, reagent aliquoting, reaction, and detection).

[0037] First, the sample dispensing mechanism 104 dispenses a predetermined amount of sample into a predetermined reaction unit on the reaction tray 109. Then, the reaction tray 109 rotates, causing the reaction unit that has dispensed the sample to move to a position close to the reagent dispensing mechanism 108.

[0038] The reagent dispensing mechanism 108 dispenses a predetermined amount of reagent into the reaction unit that has discharged the sample. Next, the reaction dish 109 rotates, moving the reaction unit that has discharged the sample and reagent to the position set by the stirring unit 110. Then, the sample and reagent are stirred by the stirring unit 110. Furthermore, the reaction dish 109 is heated to an appropriate temperature to promote the reaction between the sample and reagent.

[0039] When the reaction process between the sample and reagent on the reaction plate 109 is completed, the reaction plate 109 rotates, moving the reaction unit containing the reaction solution to the position set in the biochemical detection unit 111. Then, the reaction signal is measured by the detection unit within the biochemical detection unit 111. After the signal is measured, the reaction solution is discharged from the reaction unit through the reaction unit cleaning mechanism 112.

[0040] Furthermore, the mechanism described above in the automatic analysis device is referred to as the analysis action unit. In addition to the analysis action unit, the automatic analysis device also includes a control unit 113 and an operation unit 114 that control the overall operation of the automatic analysis device.

[0041] The control unit 113 is composed of, for example, a hardware board and a computer, and is connected to a storage device 115 such as a hard disk. The operation unit 114 is composed of an input device such as a display unit 117 with a touch panel, a mouse 118, and a keyboard 119. The storage device 115 stores, for example, the analysis items of the samples registered by the user. The control unit 113 can be composed of hardware consisting of a dedicated circuit board, or it can be composed of software executed by a computer.

[0042] In the hardware-based configuration, this can be achieved by integrating multiple processing units onto a wiring substrate, a semiconductor chip, or a package. In the software-based configuration, it can be achieved by mounting a high-speed general-purpose CPU in a computer and running a program to perform the desired processing. Existing devices can also be upgraded using a recording medium containing this program. Furthermore, these devices, circuits, and computers can appropriately transmit and receive data via wired or wireless network connections.

[0043] The following describes the application of the sample dispensing mechanism in the automated analyzer. The same structure is also used in the reagent dispensing mechanism, enabling detection of abnormal liquid dispensing. Due to repetition, the description of the reagent dispensing mechanism is omitted.

[0044] Figure 2 This is a schematic diagram of the sample dispensing mechanism. The sample probe (also called the sample dispensing probe or dispensing probe) 201 is connected to the sample syringe (also simply called the "syringe") 203 via the flow path 202, and their interiors are filled with liquid.

[0045] The specimen syringe 203 consists of a cylinder 203a and a plunger 203b, with the plunger 203b connected to the syringe drive unit 204. The syringe drive unit 204 drives the plunger 203b up and down relative to the cylinder 203a, thereby aspirating and expelling the specimen.

[0046] A motor is connected to the sample probe 201 as a sample probe drive unit 205, thereby enabling the sample probe to move in the vertical and rotational directions to a predetermined position. Furthermore, the syringe drive unit 204 and the sample probe drive unit 205 are controlled by the sample probe control unit 206 (in... Figure 2 Controlled by the section marked "Control Unit".

[0047] In the case of a specimen 208 in an aspiration container (also called a specimen container) 207, a predetermined amount of air (called segmented air) is aspirated into the specimen probe before the aspiration action in order to prevent the liquid in the specimen probe 201 from mixing with the specimen 208.

[0048] Then, the specimen probe 201 is lowered to the specimen 208 by the specimen probe driving unit 205, and further suction is performed.

[0049] Regarding the descent of the sample probe at this time, the sample probe control unit 206 monitors the change in electrostatic capacitance caused by the sample probe 201 reaching the liquid surface of the sample 208, and determines the descent amount of the sample probe by controlling the sample probe drive unit 205.

[0050] When the sample aspiration action ends, the sample syringe 203 performs a gap discharge action to correct the amount of sample discharged in the next discharge action. Afterwards, the sample probe 201 moves to the sample discharge position, and the sample syringe 203 performs the discharge action.

[0051] After discharge, the cleaning water 211 in the water supply tank 210 is discharged at high pressure by the water supply pump 209, thereby cleaning the inner surface of the specimen probe 201 (this is called probe internal cleaning, or simply "internal washing," and the water used for internal washing is called "internal washing water"). The opening and closing of the flow path to the water supply tank is controlled by the solenoid valve 212. In addition, the solenoid valve 212 is controlled by the specimen probe control unit 206.

[0052] The pressure sensor 213, used to measure the pressure within the flow path 202, is connected via a branch block 214 to the flow path system, which includes the specimen probe 201, the flow path 202, and the specimen syringe 203. Here, in order to measure the pressure change of the specimen probe 201 with good sensitivity, it is desirable that the pressure sensor 213 be positioned as close as possible to the specimen probe 201.

[0053] The output value of pressure sensor 213 is amplified by signal amplifier 215 and converted into a digital signal by A / D converter 216. The digitally converted signal is sent to calculation unit 218, which calculates a determination index to determine whether aspiration was performed normally (determining whether there was empty aspiration or whether the specimen probe was blocked by fibrin, etc.) using the method described below. In determination unit 219, the determination index calculated by calculation unit 218 is compared with a threshold value to determine whether the specimen was aspirated normally.

[0054] In the above betting operation, the timing of each mechanism's action is defined within a predetermined time cycle, and continuous betting is performed by repeatedly implementing this cycle.

[0055] Furthermore, automated analysis devices are not limited to biochemical analysis devices, but can also be devices such as immunoassay devices capable of measuring different analytical items. Additionally, they are not limited to a single analytical module structure; they can also be structures that connect two or more analytical modules capable of measuring various identical or different analytical items, or pretreatment modules that perform pretreatment, via a delivery device.

[0056] Next, the flow path connecting the dispensing probe and syringe of the aforementioned automatic analysis device will be described. Flow path 202 is a tube connecting syringe 203 and dispensing probe 201, and the interior of flow path 202 is filled with water (system water). Syringe 203 causes a pressure change within flow path 202. Generally, a rod-shaped piston is provided inside the outer cylinder. By moving the piston along the length of the cylinder, the internal volume of the cylinder changes, generating pressure. In addition, any pump that causes a pressure change, besides syringes, can also be used, such as a peristaltic pump or other known pumps.

[0057] The dispensing probe 201 has the following function: using the pressure change generated by the syringe 203, it draws a predetermined amount of reagents, samples, etc., from a container holding liquids such as reagents and samples, and discharges a predetermined amount into other containers such as a reaction vessel. A dispensing nozzle, immersed in the drawn liquid, is provided at the tip of the dispensing probe 201. Depending on the context, the dispensing probe as a whole, including the dispensing nozzle, is sometimes referred to as a dispensing probe, or simply a probe. For example, the expression "immersing the tip of the dispensing probe in liquid" is sometimes used.

[0058] The dispensing probe 201 is installed at... Figure 1 The rotating axis shown is approximately the front end of an arm that rotates in an arc around its center. This arm rotates and moves up and down, immersing the probe tip in reagent and sample containers located at predetermined positions, attracting a predetermined amount of reagent and sample. Then, the probe is lifted, causing the arm to rotate, thereby discharging a predetermined amount of reagent and sample into other containers at the dispensing destination. In addition to reagents and samples, various liquids such as cleaning solutions and water can be used as the aspirating fluid.

[0059] The flow path 202 can be configured in various shapes according to the layout within the automatic analysis device, but... Figure 3 In the middle, the flow path near the syringe 203 becomes the highest position (location A), and then, via the lowest position (location B), it connects to the dispensing nozzle again via the high position (location C) near the dispensing probe (which is mostly horizontally extended in the arm).

[0060] The reason for using the lowest position (location B) is that, for example, most devices have a reaction plate 109 with a constant temperature bath in the center, and this is to avoid the reaction plate.

[0061] Especially in small automated analyzers, due to the dense arrangement of various devices within the apparatus, the flow path 202 may need to be configured through the gaps between these devices, necessitating such a configuration. Furthermore, while the syringe 203 is generally located below the front surface of a large automated analyzer with ample internal space, in small automated analyzers, particularly benchtop models, it may be positioned above the apparatus for ease of maintenance, which is a natural consequence. Figure 3 The flow path close to the syringe 203, as shown, becomes the highest position (location A).

[0062] Here, the area connecting point A and point B is called area A, and the area connecting point B and dispensing probe 201 is called area B. In this flow path structure, the plunger 203b of syringe 203 moves at high speed in the water (sometimes called system water) filling the flow path 202, thereby vaporizing the air dissolved in the system water. When bubbles are generated, the generated bubbles float due to the difference in specific gravity and remain at the highest position (point A) in the flow path 202. Small bubbles may combine to become large bubbles and remain.

[0063] As described above, in order to clean the inner surface of the specimen probe 201, the flow path 202 is internally washed by the water supply pump 209, which discharges the cleaning water 211 from the water supply tank 210 at high pressure. Therefore, the smaller air bubbles in the flow path 202 are squeezed downstream by the internal washing water, and the air bubbles are squeezed out from the front end of the dispensing probe 201 together with the system water.

[0064] However, bubbles that become enlarged and remain at the highest position (location A) may not be able to pass through the lowest position (location B) even when the internal wash water is flowed under high pressure. The liquid (system water) in flow path 202 acts as a pressure transmission medium, but if bubbles are generated in the liquid, pressure is generated in the syringe. Even when liquid is drawn into the probe tip, the pressure is used to crush the bubbles, making accurate dispensing control difficult. Similarly, the brake fluid in a car becomes very hot due to continuous use of the brakes, and the boiling of the brake fluid generates bubbles, a phenomenon similar to the vapor lock that makes the brakes ineffective.

[0065] If the syringe 203 is moved slowly, the generation of bubbles can be suppressed to some extent, but the automatic analysis device requires a predetermined analysis throughput, so it is practically difficult to move the syringe 203 slowly.

[0066] Figure 4 Indicates the use of having Figure 3 The pressure changes within the flow path 202 during repeated dispensing are illustrated by the dispensing mechanism. During the first dispensing, the pressure change within the flow path is acute-angled. Conversely, with subsequent dispensing cycles (15th, 45th, and more), the pressure change becomes more gradual. This is evidence of the buffering effect of air bubbles. Thus, even if the plunger 203b is activated to draw 50 μL of liquid as initially designed, it may actually draw only about 45 μL, potentially leading to inaccurate analytical results.

[0067] Example 1

[0068] Figure 5The flow path structure of Example 1 is shown. In order to temporarily hold the bubble in the middle of the flow path 202, multiple portions are provided so that a part of the flow path 202 is annular in the longitudinal direction. "Formed as annular in the longitudinal direction" can also be expressed as the central axis of the annular flow path being set in a generally horizontal direction.

[0069] As described above, even if the internal wash water flows under high pressure, the enlarged bubbles trapped at the highest position (location A) may not be able to pass through the lowest position (location B). However, by providing a bubble trapping section (which can also be a bubble storage bend or bubble accumulation section for capturing bubbles) between locations A and B, the bubbles trapped at location A can be moved downwards in stages. Therefore, the generated bubbles are easily discharged from the front end of the dispensing probe 201 under the force of the internal wash water.

[0070] use Figure 6A , Figure 6B Detailed explanation of the bubble movement. (1) Internal wash 1: The bubbles generated in the syringe flow. (2) After internal wash 1 ends 1: The bubbles rise due to buoyancy. (3) After internal wash 1 ends 2: The bubbles that have crossed point 1-1 of ring 1 move towards point 1-2 due to buoyancy. (4) Internal wash 2: The bubbles that have reached point 1-2 move towards ring 2. (5) After internal wash 2 ends 1: The bubbles rise due to buoyancy. (6) After internal wash 2 ends 2: The bubbles that have crossed point 2-1 of ring 2 move towards point 2-2 due to buoyancy. That is, a temporary bubble retention area is set up between point A and point B, so that the bubbles retained at point A move little by little towards the area closer to point B, thereby removing the bubbles in the flow path 202 and continuing to dispense without affecting pressure propagation.

[0071] The diameter of the ring depends on the degree of bubble generation. For example, when the height (vertical length) from point B to point A is about 60 cm, the ring diameter is preferably about 6 cm. Depending on the pipe constituting the flow path, it is sometimes difficult to bend and form a small-diameter ring. Therefore, the diameter of the ring shape is preferably set to 6 cm to 12 cm, which is about 1 / 5 to 1 / 10 of the height difference between points A and B.

[0072] Of course, the ring diameter depends not only on the height difference between points A and B, but also on the inner diameter of flow path 202; therefore, the optimal ring diameter cannot be uniquely determined. Preferably, the ring diameter and the number of rings are determined while experimentally confirming whether the bubbles ultimately trapped at point A are squeezed out by the internal wash water. It should be noted that... Figure 5The annular flow path can be set as a single layer, but if a large number of bubbles are generated, it can also be set as a double or triple layer to increase the amount of bubbles that can be captured. In addition, the number of annular flow paths can be set to 2 to 4 or more, depending on the amount of bubbles generated, the water pressure of the internal wash water, the inner diameter of the flow path, etc.

[0073] Figure 7 Indicates the use of having Figure 5 The pressure changes during repeated dispensing in the flow path shown by the dispensing mechanism are illustrated. Figure 4 In comparison, it can be seen that even if the first, 15th, and 45th splits, as well as the number of splits, increase, the change in pressure remains almost unchanged.

[0074] Example 2

[0075] Figure 8 This indicates the dispensing mechanism of Example 2. (And...) Figure 5 The difference lies in setting the ring horizontally instead of vertically (this configuration can be represented as "the central axis of the ring-shaped flow path being set approximately vertically"). The effect of periodically squeezing out air is similar to... Figure 5 The dispensing mechanism shown is the same, but as... Figure 5 The different flow paths have different effects, compared to the vertical ring structure formed by the accumulation of bubbles in the horizontal region. Figure 5 Due to the different flow paths, the portion (volume) where bubbles are trapped is larger. Therefore, even in the case of a temporary large number of bubbles being generated, it is expected that the bubbles can be flushed away beyond point B. When the syringe is in motion and the flow path is filled with liquid, the bubbles grow faster, making it an effective structure in Example 1 when the bubble discharge cannot keep up.

[0076] Example 3

[0077] Figure 9 This describes the dispensing mechanism of Example 3. Multiple U-shaped bubble retention sections are arranged midway through the flow path. The phased air ejection effect of this structure is the same as in Examples 1 and 2. This structure is effective when the flow path material is hard, making it difficult to form a loop structure, or when the diameter must be so large as to be unacceptable within the layout of an automated analysis device.

[0078] Example 4

[0079] Figure 10 This illustrates the dispensing mechanism of Example 4. A flow path that hinders air bubble rise is provided midway through the flow path. Specifically, by providing continuous protrusions such as threaded holes, surface tension is used to capture air bubbles between these protrusions, thus achieving the same effect as a bubble trapping section as an annular flow path. This structure also has the same effect of periodically expelling air.

[0080] This structure is effective when a ring structure cannot be formed due to the material of the flow path. Furthermore, the effect can be adjusted by changing the number and structure of the water trap units. Unlike annular or U-shaped flow paths, it does not require lengthening the flow path, thus reducing the internal volume of the flow path. This allows for a more compact device design.

[0081] An obstruction structure needs to be a structure that hinders the upward movement of bubbles caused by buoyancy and has resistance to the extent that it displaces the bubbles during the flow of internal wash water. An obstruction structure can also be a valve-like construction.

[0082] Example 5

[0083] Figure 11 This describes the dispensing mechanism of Example 5. As a flow path that prevents the bubbles in Example 4 from rising, a flow path with a machined inner surface is provided. Specifically, by roughening the surface roughness of the inner surface of the tube forming the flow path, it is expected that the surface tension will be used to capture bubbles on the inner surface of the tube. Alternatively, the same effect can be expected even if a spiral groove is provided on the inner surface of the tube. Alternatively, the effect of capturing bubbles can be expected even if a cloth-like component is adhered to the inner surface of the tube. The phased extrusion of air by this structure is also the same.

[0084] This structure is effective when a ring structure cannot be formed due to the material of the flow path. The effect can be adjusted by changing the number and structure of the water trap units. Unlike annular or U-shaped flow paths, it does not require lengthening the flow path, thus reducing the internal volume. This allows for a more compact device design.

[0085] An obstruction structure is a structure that obstructs the upward movement of bubbles caused by buoyancy and has a degree of resistance that displaces the bubbles during the flow of internal wash water.

[0086] <Other>

[0087] Furthermore, the present invention is not limited to the above embodiments and can be modified and applied in various ways. The above embodiments are examples described in detail for the purpose of easily understanding the present invention and are not necessarily limited to having all the structures described.

[0088] Symbol Explanation

[0089] 101—Automatic analysis device; 102—Specimen tray; 103—Specimen container; 104—Specimen dispensing mechanism; 105—Reagent storage compartment; 106—Reagent tray; 107—Reagent container holding unit; 108—Reagent dispensing mechanism; 109—Reaction tray; 110—Stirring unit; 111—Biochemical detection unit; 112—Reaction unit cleaning mechanism; 113—Control unit; 114—Operating unit; 115—Storage device; 116—Control device; 117—Display unit; 118—Mouse; 119—Keyboard; 120—Barcode reader; 201—Specimen dispensing probe 202—Needle, 203—Specimen syringe, 203a—Cylinder, 203b—Plunger, 204—Instrument drive unit, 205—Specimen probe drive unit, 206—Specimen probe control unit, 207—Container, 208—Specimen, 209—Water supply pump, 210—Water supply tank, 211—Cleaning water, 212—Solenoid valve, 213—Pressure sensor, 214—Branch block, 215—Signal amplifier, 216—A / D converter, 217—Specimen probe control device, 218—Calculation unit, 219—Judgment unit, 220—Aspiration volume calculation unit.

Claims

1. An automatic analysis device, comprising: The dispensing probe dispenses the liquid. A syringe that generates pressure to draw liquid into the dispensing probe; and The flow path connects the dispensing probe and the syringe. The automatic analysis device is characterized by, The flow path is configured to pass through a position higher than the syringe (location A) and a position lower than the dispensing probe (location B). Between location A and location B, there is a bubble retention section for temporarily retaining bubbles generated in the syringe.

2. The automatic analysis device according to claim 1, characterized in that, The bubble retention section is formed by making a portion of the flow path into a ring shape.

3. The automatic analysis device according to claim 2, characterized in that, The central axis of the annular flow path is set in a generally horizontal direction.

4. The automatic analysis device according to claim 2, characterized in that, The central axis of the annular flow path is set in a generally vertical direction.

5. The automatic analysis device according to claim 3 or 4, characterized in that, Multiple annular flow paths are provided.

6. The automatic analysis device according to claim 3, characterized in that, The diameter of the annular flow path is 1 / 5 to 1 / 10 of the height from point B to point A, and at least two such annular flow paths are provided.

7. The automatic analysis device according to claim 1, characterized in that, The bubble retention section is constructed by forming a portion of the flow path into a U-shape and combining multiple such U-shapes.

8. The automatic analysis device according to claim 1, characterized in that, The bubble retention section forms a portion of the inner surface of the flow path into a surface shape that makes it difficult for bubbles to flow when in contact with the inner surface.

9. The automatic analysis device according to claim 8, characterized in that, The surface shape is a shape having multiple protrusions extending from the inner surface.

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