JP2000074927A - Liquid sucking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give appropriate force to a liquid suction pipe regardless of the kinds of target container, that is, a closed or open container by moving a first holding part up and down for a container without any plug without engaging it to a second holding part by a control means and moving the first holding part up and down for the container with a plug while engaging it to the second holding part by a second drive source. SOLUTION: When a pipette 12 is to be lowered, a control part 92 monitors a signal from an outer force detection circuit 55. When the contorl part 92 detects that outer force is applied to the pipette 12, it judges that a container is a closed one, stops a first motor. Otherwise, the contorl part 92 judges that the container is an open one. In the case of the closed container, a drive source 72 is driven, a washing part 60 is lowered, and a cap 69 of a container 68 is pressed and held. A motor 43 is stopped and a second motor 86 is rotated. A second holding part 74 presses down a first holding part 30 and sticks the pipette 12 into the cap 69. In the case of the open container, the motors 43 and 86 are rotated and the holding part 30 is lowered without touching the holding part 74.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid suction device for sucking a liquid in a container by using a liquid suction tube that can penetrate a plug closing a container opening.
It can be suitably used for collecting a liquid sample in a sample analyzer or the like.

[0002]

2. Description of the Related Art When sucking a liquid sample from a sealed container whose container opening is sealed by a stopper such as a rubber cap, a needle-like suction tube having a tip cut obliquely is used.

In order to prevent the suction tube from being clogged with rubber scum when the cap is pierced, (a) Japanese Patent Application Laid-Open No. 9-3044
As described in Japanese Patent Application Publication No. 00-00, there is known a suction tube provided with a suction opening on a side peripheral surface of the suction tube.

[0004] On the other hand, in order to operate without problems with a container having a cap (closed container) and a container without a cap (open container), Japanese Patent No. 2511 (b) is used.
As described in JP-A-549-549, there is known an apparatus provided with a probe for an open container and a needle for a closed container.

[0005]

When the suction tube is moved up and down, a small force is required for an open container, but a large force is required for a closed container. Providing a large force to an open container causes waste in the mechanism, impairs agility, and causes the suction tube to crash to the container bottom and damage the suction tube depending on the vertical position of the container. This also causes problems. For example, if the liquid suction pipe and its large driving source are made into one unit and the unit is to be moved in the horizontal direction, this unit is large and heavy and cannot be moved at high speed. Face the specific problem of becoming too large.

[0006] The present invention provides a liquid suction device that can provide an appropriate force to the liquid suction pipe depending on the situation, specifically for both closed containers and open containers. Make it an issue.

[0007]

According to the present invention, there is provided a liquid suction apparatus comprising: a container disposed at a predetermined position; a liquid suction pipe having a sharp end formed to suck a liquid; A first holding unit that moves in the direction, a first drive source that provides a force for moving the first holding unit up and down, and engages with the first holding unit to press and move the first holding unit up and down A second holding portion that engages with the first holding portion, presses the second holding portion to move in the vertical direction, and a second that provides a force for vertically moving the second holding portion. And a control means for controlling the above-mentioned means, and the control means does not engage the first holding portion with the second holding portion for the container without a stopper. Is moved up and down by the force of the drive source, and the first holding portion is engaged with the second holding portion for the container having the plug. By the force of the second driving source and controlling so as to move up and down.

When a container containing a liquid to be collected (for example, a sample liquid to be inspected) is placed at a predetermined position, the liquid suction tube moves toward the container. The first holding part does not engage with the second holding part when the container is open with no stopper. That is, the second holding unit does not contact the first holding unit. Therefore, the liquid holding tube can be moved by moving the first holding unit by the force of the first drive source.

When the container is a closed container having a stopper, the first holding portion engages with the second holding portion. That is, the second holding unit comes into contact with the first holding unit. Therefore, the first holding unit is pressed by the second holding unit by the force of the second drive source, and the liquid suction tube can be moved. When automatically operating while recognizing the presence or absence of a plug for each container, it is preferable to include a plug detection means for detecting the presence or absence of the plug.

In this manner, the first drive source provides a relatively small force to the liquid suction tube to move it up and down, and the second drive source provides a relatively large force to the liquid suction tube to penetrate the stopper. And can be moved up and down. That is, the driving method (the magnitude of the force to be provided) at the time of moving the liquid suction pipe can be changed depending on the situation. Further, mechanical waste can be eliminated, and high-speed operation and reliability can be ensured.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The liquid suction tube used has strength,
Metal is preferable in terms of liquid level detection, and chrome nitride (Cr) is applied to the outer wall of stainless steel pipe in terms of corrosion resistance and abrasion resistance.
It is preferable that a coating treatment of a cured film such as N) is performed.

The liquid to be sucked by the liquid suction tube is not particularly limited, but a blood sample such as plasma to be analyzed by an analyzer is one example. It is preferable from the viewpoint of automation of the analysis process that the container containing the liquid to be collected in the liquid suction device (for example, the sample liquid to be inspected) is placed on the sample rack and sequentially conveyed below the suction tube.

In the liquid suction apparatus of the present invention, external force detecting means for detecting that an upward external force acts on the liquid suction tube when the liquid suction tube moves toward the container by the force of the first drive source; Liquid level detecting means for detecting that the tip portion of the liquid suction pipe has reached the liquid level is provided, and when the external force is not detected, the control means detects liquid level detection information by the liquid level detecting means or external force by the external force detecting means. Preferably, the first drive source is stopped based on the detection information, and when the external force is detected, control is performed such that the second drive source is stopped based on the liquid level detection information by the liquid level detection unit. The external force detecting means can function as the plug detecting means.

It is more preferable that the liquid suction tube, the first holding unit, the first drive source, and the external force detecting means are provided in the first unit which can move horizontally, in order to use the liquid suction device.

In this way, even if the liquid level of the open container is different for each container, the liquid level detecting means can stop the first drive source and stop the suction pipe. That is, the amount of liquid adhering to the suction tube can be minimized. Furthermore, even if the bottom position of the open container is different for each container, the first driving source can be stopped by the external force detecting means and the suction tube can be stopped. That is, it is possible to prevent the suction tube from being in contact with the container bottom and being damaged. The second drive source can be stopped by the liquid level detecting means for the closed container to stop the suction pipe.

In the liquid suction apparatus of the present invention, it is preferable to use a liquid suction pipe which is formed such that an oblique cut surface is formed at the distal end of the pipe and no sharp edge is formed at the end of the inner wall of the pipe at the oblique cut face.

In this case, since there is no sharp edge at the end of the inner wall of the suction tube, the plug is cut off at that portion, and a part of the cut plug does not enter the opening side. That is, the suction tube is hardly clogged.

In order to prevent a sharp edge from being formed at the end of the inner wall of the tube at the tip of the liquid suction tube, the entire periphery of the inner end of the tube may be subjected to a process of removing the sharp edge. The sharp edge removal processing may be performed only on the portion.

[0019]

FIG. 1 shows a schematic configuration of an example of a liquid suction apparatus according to the present invention. FIG. 2 shows a specific configuration of an example of the liquid suction device of the present invention. This liquid suction device is built in the blood coagulation measuring device in this embodiment. FIG. 2 is a view from the left side of the blood coagulation measuring apparatus, in which the right side is the front side of the apparatus and the left side is the inside of the apparatus. A sample rack 66 holding a plurality of sample containers 68 arranged in a line
Are transported by a sampler (not shown) one container at a time from the back of the drawing to the front.

As shown in FIG. 1, the liquid suction device comprises a first unit 10 and a second unit 11. The first unit 10 is a pipette 1 which is a liquid suction pipe.
Holding unit 30 for holding 2 and first holding unit 30
Is provided with a drive source 43 for vertically moving the. Second
The unit 11 includes a second holding unit 74 that engages with the first holding unit 30, and a drive source 86 for vertically moving the second holding unit 74. The first unit 10 is horizontally movable. The two-dot chain line indicates a state in which the first unit 10 is located at the forefront, the first holding unit 30 is close to the second holding unit 74, and both can be engaged. The solid line indicates a state in which the first unit 10 is located at the rear, the first holding unit 30 is separated from the second holding unit 74, and both cannot be engaged.

The pipette 12 has an internal passage 14 (see FIG. 4).
And a stainless steel cylindrical tube having an outer diameter of 2.0 mm, an inner diameter of 1.3 mm, and a total length of about 130 mm. An electric wire 34 is connected to the upper end of the pipette 12. Electric wire 34
Is connected to the liquid level detection circuit 35, and detects the liquid level based on a change in capacitance (capacitance) when the pipette tip contacts the liquid level. A tube 36 is connected to the upper end of the pipette 12 and the tube 36 is connected to a liquid metering device 37 such as a syringe pump. In this embodiment, the first unit is moved in the horizontal direction by the driving sources 94 and 96.

FIGS. 3 and 4 are a partially enlarged view and a partially enlarged sectional view of the tip portion of the pipette. The pipette 12 is narrowed to 1.2 mm in outer diameter and 0.5 mm in inner diameter in the vicinity of the lower end, and is sharply cut obliquely to the pipe axis as shown in the figure. The internal passage 14 has an opening 18 in the oblique cut surface 16.
Simply cutting obliquely generates an acute edge at the inner wall end 21 of the oblique cut surface 16.
An acute angle edge occurs at 0, and an obtuse edge occurs at the lower half circumference 22).

FIG. 5 shows a state where the rubber cap is pierced in the conventional pipette 13. Since there is an acute edge at the end of the inner wall, the rubber cap 24 is cut at the acute edge 23 when the rubber cap is pierced, and a part (rubber scum) of the cut rubber cap enters the opening, so that clogging occurs immediately. .

Therefore, the upper half-circumferential portion 20 is subjected to a chamfering process for removing sharp edges. As a result, it was possible to eliminate sharp edges around the entire inner wall end, and it was confirmed that clogging did not occur even in at least 30,000 continuous tests. The pipette 12 has a coating of chromium nitride (CrN) applied to the outer wall in a region up to about 80 mm from the lower end in order to increase abrasion resistance.

FIG. 2 is a partially cutaway side view of one embodiment of the liquid suction device. 44 is a first chassis of the first unit 10. 40 and 41 are pulleys, 42 is a pulley 4
It is a belt stretched between 0 and 41. One pulley 4
Reference numeral 1 is directly connected to a shaft of a motor 43 (stepping motor in this embodiment), which is a first drive source. If a member is attached to a part of the belt 42, the member can move up and down by rotation of the first motor 43.

The first unit 10 is provided with external force detecting means 54 for detecting when an upward external force acts on the pipette 12. The member 50 attached to the belt 42 via the member 48 is rotatably supported by the second chassis 38. The second chassis 38 is the first chassis 4
The guide shafts 46 and 47 attached to the guide member 4 guide only the vertical movement. A first holding unit holding the pipette 12 is attached to the second chassis 38. A biasing means 52 such as a compression coil spring is arranged between the second chassis 38 and the member 50.

When no external force is applied to the pipette 12, the member 50 is a member 54 provided on the second chassis 38.
Is urged in the clockwise direction in the figure with the fulcrum as a fulcrum, and abuts on a locking portion 56 provided on the second chassis. Therefore,
By the rotation of the first motor 43, the first holding unit 30, the second chassis 38, and the member 50 move up and down integrally.

If an object comes into contact with the pipette 12 during downward movement of the pipette and an upward external force acts, the member 4 of the member 50
8 moves downward, but the fulcrum 54 side of the second chassis 38 stops, so that the member 50 rotates counterclockwise relative to the compressive force of the spring 52 as shown by a two-dot chain line. I do. This minute change is detected by a sensor 53 such as a microswitch. The sensor 53 is connected to an external force detection circuit 55 by an electric wire, and external force detection is performed.

Reference numeral 58 denotes a guide member having a through hole and functioning as a guide means for a pipette which moves up and down. The guide member 58 is attached to the first chassis 44. In the present embodiment, since the pipette 12 has a length of 100 mm or more, it is provided to prevent horizontal blurring when moving.

Reference numeral 60 designates a through-hole 63 (see FIG. 1) for supplying a cleaning liquid from the port 62 to the through-hole 63 and a port 64.
Is a washing section for washing the wall of the pipette 12 by discharging waste liquid from the pipette. The cleaning unit 60 is moved up and down by a driving source 72 such as an air cylinder via a member 70. 71
Is a guide rail provided in the vertical direction to guide the member 70.

Next, the second unit will be described. 74 is a second holding unit that can be engaged with the first holding unit 30. In this embodiment, the two parts 30, 74 are connected by fitting of the concave part and the convex part. The first holding portion 30 is provided with a convex portion 32. The second holding portion 74 is provided with a concave portion 76 into which the convex portion 32 is fitted with a gap.
The vertical width of the convex portion 32 is about 6 mm, and the vertical width of the concave portion is 14 mm. The first holding portion has a margin that can move without interference of the second holding portion, that is, a non-interference range of 8 mm. I have.

Reference numeral 80 denotes a drive shaft which is rotatably supported by bearings 84 and 85 and has a spiral groove. Reference numeral 82 denotes a mover which is screwed to the drive shaft 80 and moves up and down as the drive shaft 80 rotates. Drive shaft 80
A pulley 89 is attached to one end of the second motor (stepping motor) 86 via a pulley 88 and a belt 90.
Is transmitted to the drive shaft 80. The second holding portion 74 is attached to the moving member 82 via a member 78 and moves up and down while being guided by the guide rail 71.

When the power supply to the first motor 43 is stopped and the second motor 86 is rotated when the first holding portion 30 and the second holding portion 74 are in the engaged state, the second holding portion 74 Can press and move the first holding unit 30. At this time, the first motor 43 is forcibly rotated by an external force.

In this embodiment, the first unit 10 is a motor 9
4 is configured to move horizontally in the horizontal direction on the paper. The motor 96 is also configured to move horizontally in the front and back directions on the paper. When the first unit 10 is on the front side (right side) of the apparatus, the first holding portion 30 and the second holding portion 74 are engaged. 1st unit 1
If 0 moves rearward (left side), the engagement between them is released,
The pipette 12 moves up and down solely by the rotation of the first motor 43.

In this embodiment, a sample container containing plasma, which is a sample liquid, is transported by a sampler mounted on a sample rack 66 on which, for example, ten containers can be mounted. FIG. 6 shows a sample rack 66 viewed from the front side of the blood coagulation measuring apparatus. The sample rack 66 is intermittently moved one sample container at a time from right to left, and is sequentially arranged below the pipette. The sample containers used in this embodiment are roughly classified into three types. The first type is a closed container a mounted on the bottom wall of the sample rack 66,
b, c, d, e, f (the container bottom is in contact with the sample rack bottom wall). Each container has a different cap. Second
The seed is an open container g placed on the bottom wall of the sample rack (the bottom of the container is in contact with the bottom wall of the sample rack). The third type is an open container h, i, j placed above the bottom wall of the sample rack.
(Each container is provided with a flange, and abuts on the top wall of the sample rack and abuts on the upper end of the open container for mounting. The bottom of each open container abuts on the bottom wall of the sample rack. Not in contact).

In this embodiment, since the tapered portion 61 is provided on the lower surface of the through-hole 63 of the washing unit 60, the position is shifted even in a unique container such as f (a vacuum blood collection tube made by MONOVETTTE manufactured by SARSTEDT). The container can be held without the need.

The control section 92 receives a signal from the sensor and drives each motor according to a program. The operation of the liquid suction device will be described.

<Step 1: Detection of presence or absence of container cap>
When the first unit 10 is located at the forefront, the first unit
By rotating the motor 43 and the second motor 86 to lower the first holding unit 30 and the second holding unit 74 together, the pipette 12 is moved to the initial position (uppermost point) while maintaining the non-interference state. Through the cleaning unit 60 and lowered by a predetermined distance. During that time, the control unit 92 monitors a signal from the external force detection circuit 55. If it is detected that an external force acts on the pipette 12, it is determined that the container is a closed container with a cap, and the first motor 43 is stopped. If no external force acts on the pipette 12 even if the pipette 12 is lowered a predetermined distance, it is determined that the container is an open container without a cap.

<Step 2-1: Lowering (piercing) the pipette in the case of a closed container> The stopped first motor 43 is rotated very slightly in the opposite direction to release the tip of the pipette 12 from the cap. Then, the drive source 72 is driven to lower the cleaning unit, and the cap 69 of the container 68 is pressed and held by the lower surface of the cleaning unit 60. Stop the power supply to the first motor 43,
The second motor 86 is rotated. The second holding part 74 pierces the pipette 12 into the cap 69 of the container 68 by pushing down the first holding part 30 (the pipette 12 is lowered solely by the force of the second motor 86). Then, the second motor 86 is stopped and the pipette 12 is also stopped based on any of the liquid level detection information from the liquid level detection circuit 35 and the position information that the preset lowermost point has been reached.

<Step 2-2: Lowering of Pipette in Open Container> The first motor 43 and the second motor 86 are continuously rotated to move the first holding unit 30 to the second holding unit 74. (The pipette 12 is lowered by the force of the first motor 43). Then, the first motor 43 is driven by one of the liquid level detection information from the liquid level detection circuit 35, the external force detection information from the external force detection circuit 55, and the position information indicating that the preset lowermost point has been reached. The pipette 12 is stopped, and the pipette 12 is also stopped.

<Step 3: Suction of Sample Liquid> The pipette 12 is lowered by a predetermined distance in accordance with the suction amount, and the liquid metering device 37 is operated to suction a predetermined amount of plasma from the opening 18 at the tip of the pipette 12 (from 5 μl to 500 μl). . In addition,
If the pipette 12 stops descending due to reaching the lowest point in step 2-1 and if the pipette 12 stops descending due to external force detection or reaching the lowest point in step 2-2, there is no plasma to be aspirated. Therefore, an error message indicating that there is no sample liquid is output without suctioning the liquid.

<Step 4-1: Lifting (Pull Out) of Pipette in Closed Container> The second motor 86 is rotated in the reverse direction while the power supply to the first motor 43 is stopped. The pipette 12 is pulled out of the cap 69 of the container 68 by the second holding part 74 pushing up the first holding part 30 (the pipette 12 is raised solely by the force of the second motor 86). At the same time, the cleaning liquid is supplied to the cleaning unit 60, the waste liquid is discharged, and the outer wall of the pipette 12 is cleaned. When the drawing is completed, the cleaning unit 60 is raised to release the holding of the container 68. The pipette 12 returns to the initial position.

<Step 4-2: Lifting of Pipette in Open Container> The first motor 43 and the second motor 86 are rotated in the reverse direction so that the first holding section 30 contacts the second holding section 74. Raise without touching (Pipette 12 is the first
Of the motor 43). Cleaning unit 60 at the same time
The cleaning liquid is supplied to and the waste liquid is discharged to wash the outer wall of the pipette 12. The pipette 12 returns to the initial position.

<Step 5: Pipette Rearward Movement> The motor 94 is rotated to move the first unit 10 backward.
As a result, the first holding portion is completely released from the engagement with the second holding portion. Further, the first unit may be moved laterally by rotating the motor 96 as required.

<Step 6: Pipette Lowering> Since the engagement of the second holding part 74 is released from the first holding part 30, the pipette 12 is lowered by a predetermined amount by rotating only the first motor 43. Let it.

<Step 7: Discharge of Sample Liquid> The liquid metering device 37 is operated to discharge a predetermined amount of plasma from the opening 18 at the tip of the pipette 12 into a reaction vessel (not shown).

<Step 8: Lifting of Pipette> The first motor 43 is rotated in the reverse direction to raise the pipette 12. Then, the inner and outer walls of the pipette 12 are washed. For example, motor 9
The pipette 12 is moved to a cleaning container (not shown) by the motor 4 or the motor 96 for cleaning. Alternatively, the cleaning liquid may be supplied to the internal passage 14 of the pipette 12 to supply the cleaning liquid to the cleaning unit 60, and the waste liquid may be discharged from the cleaning unit 60 to clean the inner and outer walls of the pipette 12.

<Step 9: Pipette Forward Movement> The first unit 10 is moved forward by rotating the motor 94 in the reverse direction. The pipette 12 returns to the initial position. The first holding unit is in a state where it can be engaged with the second holding unit.

[0049]

According to the liquid suction device of the present invention, the first holding portion holding the liquid suction tube is moved up and down by the first driving source, and can be engaged with the first holding portion. The holding unit is moved up and down by the second drive source. For an open container without a plug, the first holding unit does not engage with the second holding unit, so that the first holding unit is moved by the force of the first driving source to move the liquid suction tube. Can be. In the case of a closed container with a stopper, the first holding portion engages with the second holding portion, so that the second holding portion presses the first holding portion with the force of the second driving source. The liquid suction tube can be moved. In this way, the driving method for moving the liquid suction tube can be changed depending on the situation. In addition, mechanical waste can be eliminated, and high-speed operation and reliability can be ensured.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a liquid suction device according to the present invention.

FIG. 2 is a partially cutaway side view of the liquid suction device according to the present invention.

FIG. 3 is a side view of a distal end portion of the liquid suction tube.

FIG. 4 is a side sectional view of a distal end portion of the liquid suction tube.

FIG. 5 is a side view when a rubber cap is pierced in a conventional liquid suction pipe.

FIG. 6 is a front view of a sample rack in which various sample containers are mounted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 1st unit 11 2nd unit 12 Liquid suction pipe (pipette) 16 Diagonal cut surface 20 Pipe inner wall end 30 1st holding | maintenance part 35 Liquid level detection means 37 Liquid quantitative device 43 1st drive source (motor) 54 External force detection Means 60 Cleaning unit 68 Sample container 74 Second holding unit 86 Second driving source (motor) 92 Control unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadashi Bando 7-2, Minatojima-Nakamachi, Chuo-ku, Kobe Within Toa Medical Electronics Co., Ltd. (72) Inventor Kazuya Fukuda 7-2-2, Minatojima-Nakamachi, Chuo-ku, Kobe-shi No.1 F-term in Toa Medical Electronics Co., Ltd. (reference) 2G058 CA02 EA08 EA14 ED07 ED10 ED12 ED14 ED38 GB02 GB10

Claims (4)

[Claims] A container disposed at a predetermined position, a liquid suction tube having a sharpened tip and capable of sucking a liquid, a first holding portion that holds the liquid suction tube and moves vertically. A first for providing a force for vertically moving the first holding unit;
A second holding unit that engages with and presses the first holding unit and moves in the vertical direction; and a second unit that provides a force for vertically moving the second holding unit.
And a control means for controlling the above means, wherein the control means does not engage the first holding portion with the second holding portion for the container without the stopper. The first holding portion is engaged with the second holding portion for a container having a plug, and the container is vertically moved by the force of the second driving source. A liquid suction device characterized by the above-mentioned. 2. An external force detecting means for detecting that an upward external force acts on the liquid suction tube when the liquid suction tube moves toward the container by the force of the first driving source, and a liquid suction tube tip portion. A liquid level detecting means for detecting that the liquid level has been reached, and the control means, if the external force is not detected, based on the liquid level detection information by the liquid level detecting means or the external force detection information by the external force detecting means. 2. The liquid suction device according to claim 1, wherein the first drive source is stopped, and when the external force is detected, the second drive source is stopped based on liquid level detection information by a liquid level detection unit. 3. The liquid suction device according to claim 1, wherein an oblique cut surface is formed at a tip end of the liquid suction tube, and an acute edge is not generated at an end of the inner wall of the tube at the oblique cut surface. apparatus. 4. The liquid suction tube according to claim 3, wherein a sharp edge removal process is performed on a half peripheral portion of the inner end of the liquid suction tube.