JPH11264830A - Automatic dispensing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic dispensing apparatus for safely and rapidly returning a liquid to be dispensed in the case of occurring a closed state at a nozzle or a pipe during a dispensing operation. SOLUTION: The automatic dispensing apparatus comprises a nozzle 1 for sucking and discharging a liquid in and from a container, a piping tube 2 coupled to the nozzle 1, a pump 3 connected to the tube to pressurize and pressure- reduce, a pressure sensor 4 provided in the tube 2 between the nozzle 1 and the pump 3 to detect an internal pressure of the tube 2, and a controller 50 for controlling to drive the nozzle and the pump by referring pressure information from the sensor 4. In this case, at the time of detecting occurrence of a closed state of the nozzle 1 or the tube 2 during a suction period of the liquid, the controller 50 moves the nozzle 1 to a preset position to a liquid level height in the container and to return the liquid to the original container.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic dispensing apparatus for dispensing a liquid contained in a container into another container.

[0002]

2. Description of the Related Art In clinical examinations in the medical field, blood is collected from a patient by a blood collection tube, centrifuged, and the supernatant serum is collected to perform various analyses. In a conventional automatic dispensing apparatus, a liquid (sample) contained in a container of a supply source is sucked by a movable dispensing nozzle, and the liquid is dispensed to a plurality of containers in a designated amount. Perform the operation. The dispensing tip made of a disposable plastic is often used for the nozzle used at this time in order to prevent contamination (contamination) between samples.

[0003] A piping tube is connected to the nozzle, and a pump is connected to the other. A sample is suctioned and discharged by the pressure of the pump. A pressure sensor that detects the pressure in this pipe is provided in the piping tube between this nozzle and the pump, and dispensing starts from liquid level detection based on the output fluctuation of the pressure sensor at the moment when the nozzle is inserted into the sample from the air. It is used for various controls related to the operation.

[0004] In a normal clinical test, a serum serving as a specimen is often dispensed while centrifuging blood.
In particular, when the amount of serum required for analysis is insufficient, a viscous separating material or the like may be clogged at the tip of the nozzle during suction using the automatic dispensing apparatus, which may cause a blockage. Further, there is a case where the inside of the nozzle is closed due to inhalation of fibrous fibrin or the like contained in serum. With respect to such a problem, a method of detecting this closed state by a pressure sensor is proposed in Japanese Patent Application Laid-Open No. 6-27120. When such a blockage occurs, the dispensing operation of the corresponding sample is stopped because the predetermined dispensing can no longer be performed, and the sample aspirated into the nozzle is returned to the original sample tube, and then the nozzle is disengaged. An operation of discarding may be performed.

[0005]

However, if the sample remaining in the nozzle is to be returned to its original height at the time of suction, the sample remaining in the nozzle due to the influence of the separation material or the like is completely removed. May not be returned. Further, even if the nozzle is returned to the height for horizontal transfer and the ejection operation is performed, the ejection direction does not go directly below due to the clogging state, and the sample may be scattered outside the sample tube.

[0006] Even if the so-called "return operation" of the sample is performed as described above, depending on the completely closed state, the sample remains in the nozzle and the inside of the piping tube has a positive pressure (ie, atmospheric pressure). If the discard operation is performed on the nozzle as it is, the positive pressure causes the sample in the nozzle to leak out during the movement of the nozzle to the discard position, and the sample is scattered around. There is also the danger that it will occur. Therefore, an object of the present invention is to provide an automatic dispensing apparatus that can safely and quickly return and process liquid to be dispensed when a nozzle or a pipe becomes clogged during the dispensing operation.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and the following measures have been taken to solve the above-mentioned problems and achieve the object. That is, a nozzle for sucking / discharging the liquid in the container, a piping tube connected to the nozzle, a pump connected to the nozzle and the piping tube for increasing / decreasing pressure, and the piping between the nozzle and the pump. A pressure sensor provided in the tube and configured to detect a pressure in the tube, and an automatic dispensing device including a control unit that drives and controls at least the nozzle and the pump while referring to pressure information from the pressure sensor, When detecting the clogging of the nozzle during the suction of the liquid, the control unit moves the nozzle to a position set in advance with respect to the liquid level in the container to transfer the liquid to the container. It is configured so that it can be controlled to return to. When detecting the clogging of the nozzle during the suction of the liquid, the control unit, after returning the liquid, cancels the positive pressure generated in the piping tube, returns to the atmospheric pressure, and then returns to the atmospheric pressure. It is configured to control to perform the transfer operation.

[0008] The control unit controls the return of the liquid to the same container by pulling out the nozzle once from the liquid surface, raising the nozzle to a preset distance, and controlling the automatic dispensing. Provide equipment. Further, the control unit is configured to sequentially monitor the generation of the negative pressure in the piping tube even during the suction operation of the nozzle.

(Operation) The automatic dispensing apparatus of the present invention having the above-described means has the following effects. According to the first and third aspects, even when the nozzle is clogged during the suction of the liquid, the liquid remaining in the nozzle can be returned to the original container without being scattered around. Even if the liquid remains in the nozzle after the liquid returning operation, it is possible to prevent the surroundings and the device from being stained by dropping or the like.

According to the second aspect of the present invention, since the positive pressure generated in the nozzle or the pipe due to the blockage generated during the dispensing operation can be eliminated, the nozzle does not squirt to the surroundings. It is possible to safely discard and replace even in a discard operation or the like. According to the aspect of the fourth aspect, since the pressure in the pipe is constantly checked during the suction, the blockage is light, so that it is possible to promptly shift to the return operation, complete blockage can be prevented, and dispensing by the same nozzle. Is more likely to be retried.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an automatic dispensing apparatus according to the present invention will be described in detail with reference to a plurality of embodiments and modifications thereof. (First Embodiment) FIG. 1 shows a piping diagram of an automatic dispensing apparatus according to an embodiment of the present invention. The dispensing apparatus includes a nozzle 1 for aspirating and discharging a sample (not shown) in a container, a pump 3 for applying a pressure to the nozzle 1 or a pressure reduction, and a piping tube 2 for connecting the pump 3 and the nozzle 1. It is basically composed of The automatic dispensing device of the present invention further comprises:
A three-way valve 10 that divides this path into a nozzle side and a pump side is provided on a pipe path composed of the pipe tube 2, and a pressure sensor 4 for detecting the pressure is provided on the path on the nozzle 1 side. .

The automatic dispensing apparatus of this embodiment further includes a control unit 50 for controlling the nozzle 1, the pump 3 and the three-way valve 10 via a drive system (not shown) for driving each of them. Are electrically connected, and the pressure sensor 4 sends a detection signal indicating the pressure on the nozzle 1 side to the control unit 50.
It is electrically connected so that it can be sent to

(Function and Effect 1) The feature of the automatic dispensing apparatus of the first embodiment configured as described above is that clogging of the nozzle 1 during a suction operation of a liquid in a container (not shown), for example, a predetermined sample is performed. When the pressure sensor 4 detects, the control unit 5
Numeral 0 is characterized in that the nozzle 1 is moved to a predetermined distance with respect to the liquid level of the liquid in the container, for example, is controlled so as to be raised to return the liquid to the original container safely.

FIGS. 2 (a) to 2 (f) show the vertical movement of the nozzle when aspirating a sample. By centrifugation, the liquid in the container is separated into a serum layer 7 on the upper side and a blood cell layer 9 on the bottom side at the separation material layer 8. Here, in the automatic dispensing apparatus having the above-described configuration, the pressure sensor 4 detects the liquid level based on a change in pressure when the tip of the nozzle 1 enters the serum layer 7 of the sample from the atmosphere (FIG. 2A). 200 state). From this state, the serum is sucked while lowering the nozzle 1 by a required amount.

If the amount of serum in the sample tube is smaller than the required dispensed volume immediately before the completion of the aspirating operation of serum as shown in FIG. 2 (b) 201, the nozzle 1 will be turned off as shown in FIG. Of the nozzle enters the separation material layer 8, but at this time, the nozzle tip may be clogged with the viscous separation material. Normally, the negative pressure in the piping tube 2 is higher when the separating material is sucked in than when the serum is suctioned, so that the blockage in this state can also be detected by the pressure sensor 4.

In such a state, the required amount of serum cannot be dispensed from the beginning, and an accurate discharge amount cannot be obtained when the tip of the nozzle (tip) is clogged. The aspirated serum is returned into the sample tube and dispensing is interrupted. However, as shown by 203a in FIG. 2 (d), when the serum in the nozzle 1 is pushed out while maintaining the nozzle height at the time of suction, the serum is pushed in a state where the nozzle 1 is pushed into the separation material. Cannot be reliably returned to the sample tube.

As shown at 203b in FIG. 2E, the nozzle 1 is moved to the upper point (ie, the height at which the nozzle is horizontally moved).
If the serum in the nozzle 1 is ejected after being transferred to the nozzle 1, there is a risk that the ejection will not go downward and go out of the sample tube as indicated by a broken line arrow depending on the clogged state of the nozzle tip. In the dispensing apparatus, as shown at 203c in FIG. 2 (f), the control units 50 respectively raise and discharge the nozzle 1 to a set height above the height at which the liquid level was first detected. The synchronous control of the drive system is performed. With this control, the sample is reliably returned, and it is possible to prevent the sample remaining outside the sample tube from being seeded during the so-called “return operation” of the serum remaining in the nozzle 1.

Further, depending on the state of clogging of the nozzle tip, even when the sample is returned, the serum may not be completely ejected, or may remain in the nozzle without being ejected at all. When the nozzle 1 is transferred from the sample aspirating position to the nozzle discarding position in such a state, there is a possibility that serum in the nozzle may be ejected during the nozzle transfer because the pressure inside the sample tube 2 is high. However, before the transfer of the nozzle 1, the inside of the pipe tube 2 is opened to the atmosphere by the three-way valve 10 (that is, the nozzle-side valve 101 and the atmosphere-side valve 103 of the three-way valve are brought into conduction), and the pressure is brought to the atmospheric pressure state. Then, before the nozzle is transferred, the pipe tube 2 is sealed (that is, the three-way valve 101 and the pump valve 10 are closed).
By controlling 2 to a conducting state, it is possible to prevent the ejection of serum.

According to the automatic dispensing apparatus of the present invention controlled as described above, even if the nozzle is clogged during the dispensing operation, when the sample remaining in the nozzle is returned to the blood collection tube or the like, dripping or dropping occurs. No scattering occurs. Further, even if the sample in the nozzle remains after the returning operation of the sample, no dripping or scattering to the surroundings occurs, so that no contamination of the sample or a contamination accident by the sample in the apparatus occurs.

(Modification 1) In the dispensing operation of the automatic dispensing apparatus of this embodiment, the following simultaneous control may be performed. For example, as shown in FIG. 2 (a), immediately after the nozzle 1 comes into contact with the liquid level and the liquid level is detected, a descending operation is performed in which the nozzle tip is sunk into the liquid by a predetermined distance to suck the serum layer 7.

In the operation of returning the once aspirated sample to the same container as shown in FIG. 2 (f), especially when retrying dispensing is assumed, the sample is gently returned to the original state in the container. In addition, in order to prevent the sample from adhering to the side wall or the like in the container together with the necessity, the discharging operation is performed while gradually raising the nozzle tip from below the height at which the sample is present in the container in association with the liquid level rise. May be controlled.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
1 shows a piping diagram of an automatic dispensing device according to an embodiment. Book second
The embodiment has a very simple configuration that does not include the three-way valve and its drive system, as compared with the configuration of the first embodiment described above. That is, a nozzle 1 for aspirating and discharging a sample, and a pump 3 for applying a pressure or a reduced pressure to the nozzle 1
And a piping tube 2 connecting the pump 3 and the nozzle 1, and a pressure sensor 4 for detecting the pressure is provided on a path of the piping tube 2. The nozzle 1 and the pump 3 constituting the automatic dispensing apparatus are electrically connected to a control unit 50 for controlling the nozzle 1 and the pump 3 via a drive system (not shown) for driving the nozzle 1 and the pump 3.
Is connected so that a detection signal indicating the pressure of the piping tube 2 and the nozzle 1 can be sent to the control unit 50.

In the present embodiment, the components are simplified, and when the pressure sensor 4 detects clogging of the nozzle 1 during suction of the liquid, the control unit 50 uses the liquid once sucked into the nozzle 1 as a basis. After returning to the container, the nozzle 1 is transferred after controlling so as to eliminate the positive pressure in the piping tube 2.

The automatic dispensing apparatus having the above-described configuration is similar to that shown in FIG.
A series of dispensing operations are executed as follows according to the procedure of the flowchart shown in FIG. First, at the same time as the operation starts, the pressure sensor 4 detects the liquid level by a change in pressure when the tip of the nozzle 1 enters the serum layer 7 of the sample from the atmosphere (S1).
0). The pump 3 is driven to generate a predetermined negative pressure in the piping tube, and the sample is sucked by the nozzle 1 inserted at a predetermined depth (S20).

In step S30, it is determined by the pressure sensor 4 whether the nozzle 1 is clogged, that is, whether the nozzle 1 is clogged at the time of aspirating the sample (S30). If there is no clogging, a normal dispensing operation (S90) is performed, and then a series of processing is ended. On the other hand, when the blockage of the nozzle 1 is detected, the “return operation” of the sample is performed. That is, the sample once suctioned into the nozzle is discharged into the original container (S4).
0).

After the returning operation of the sample, the tip of the nozzle 1 is raised from the liquid level (S50). At this time, in step S60, the pressure in the pipe tube 2 is detected (S60). When the pressure in the tube 2 is a positive pressure, particularly when the pressure is higher than the atmospheric pressure, the clogging is determined to be "imperfect return of the sample" and the pump 3
The predetermined suction operation is performed until the positive pressure in the piping tube 2 drops to the atmospheric pressure and is eliminated (S70). on the other hand,
Otherwise, it is determined that the inside of the tube is at atmospheric pressure or a pressure similar thereto, and the process proceeds to step S80.

In a state where there is no positive pressure in the piping tube 2, in step S80, a predetermined discarding operation of the nozzle 1 or an operation for retrying the dispensing operation using the nozzle 1 again, that is, an operation for retrying. (S80), and if desired, the process returns to the first processing step S10 again to repeat the same processing operation. For example, the program may be changed so that step S30 is performed in parallel with step S20 and pressure monitoring can be performed frequently so that the pressure in the piping tube is constantly monitored during the suction operation.

(Function and Effect 2) FIG. 5 is a graph showing a state in which a pressure sensor detects a pressure in a pipe of a nozzle or the like that changes with the dispensing operation of the automatic dispensing apparatus of the present invention. The vertical axis indicates the pressure in the tube (however, the upper side is negative pressure, negative pressure: -P, the lower side is positive pressure including atmospheric pressure: + P), and the horizontal axis is operating time. In a state set at the start of the first dispensing operation, an internal pressure equal to a so-called "air (atmospheric pressure)" state is detected in the pipe and the nozzle. When the nozzle descends and comes in contact with the liquid surface, it suddenly changes from this air state to liquid,
A slight negative pressure is temporarily generated at t1. Thereafter, the suction operation is continuously performed by increasing the pump output. If the suction operation normally changes without clogging in the vicinity of t2, the normal suction is performed with the change indicated by the broken line, and then the nozzle is moved to the upper point. The aspirated sample is dispensed into another container or the like to return to the original air state.

On the other hand, if clogging occurs at t2,
As indicated by the solid line 30, the pipe pressure increases rapidly and reaches a peak at t3. Since the occurrence of clogging is recognized by the rapid pressure increase, the operation shifts to the return operation thereafter. The above-described return operation of lowering the pump output to stop the suction operation, gradually increasing the internal pressure and discharging the clogged one into the original container is performed, but if the discharge is not completed in the vicinity of t4, as shown by the solid line 40, May generate positive pressure. When the pressure sensor detects this state, the pump is slightly driven in the pressure reducing direction so as to eliminate the positive pressure, and is returned to the air state near t5 when the pressure reaches the atmospheric pressure. In this case, it is determined that normal specimen return was not possible. If it is not possible to completely restore the normal state, the nozzle is determined to be inevitable to be discarded, transferred to a predetermined discarding position, and then replaced with a new nozzle in a state where the positive pressure is lost.

As described above, the control unit 50 judges the state of the pipe (for example, liquid level detection, normal suction, occurrence of blockage, etc.) while sequentially recognizing the change in the pipe pressure, and appropriately controls each drive system. Therefore, according to the second embodiment, by eliminating the positive pressure generated in the nozzle 1 and the piping tube 2 before the nozzle transfer, the sample is scattered and dispersed around the nozzle 1 not used anymore in the discarding operation or the like. Can be prevented from being contaminated.

Further, since the pressure in the pipe is constantly monitored during the suction, the occurrence of the blockage is small, so that the operation can be promptly shifted to the returning operation and the operation can be returned to the normal state. In addition, since a completely closed state can be prevented, the state can be relatively easily restored, so that the possibility of retrying the dispensing with the same nozzle is increased, the operation efficiency is improved, and the disposal cost is reduced.

(Modification 2) In the dispensing operation of the automatic dispensing apparatus of this embodiment, the following control may be performed. In this embodiment, the positive pressure is eliminated and the waste is safely discarded. However, even if it is to be discarded, it is desirable to return the specimen and contents to the original container as much as possible. Therefore, for example, a hole is physically made in the closed part of the tip of the nozzle using a needle-shaped material to completely eliminate the closed state, the operation of returning the sample, and the substance attached near the nozzle tip washed away with the sample. A return operation may be further added.

(Other Modifications) The shape, size, material, etc. of each part relating to the exemplified automatic dispensing apparatus are as follows.
Various changes can be made as needed, and appropriate combinations with others are also possible. Further, the combination of the automatic dispensing apparatus of the present invention with other existing technologies, and the liquids and containers to be used are not limited to those in the exemplified medical field, and any appropriate ones can be used as desired. The present invention can be implemented in various modifications other than the above-described examples as long as they do not depart from the gist of the present invention.

The present invention includes the following inventions. [1] A nozzle for sucking / discharging a liquid in a container, a piping tube connected to the nozzle, a pump connected to the nozzle and the piping tube for increasing / decreasing pressure, and a pump between the nozzle and the pump. A pressure sensor disposed on the pipe tube for detecting a pressure in the pipe tube; and a control unit for controlling at least the nozzle and the pump while referring to pressure information from the pressure sensor. An injection device, wherein the control unit moves the nozzle to a position set in advance with respect to a liquid level in the container when detecting clogging of the nozzle during suction of the liquid. And controlling the liquid to return to the container.

[2] A nozzle for sucking / discharging the liquid in the container, a piping tube connected to the nozzle, a pump connected to the nozzle and the piping tube for increasing / decreasing pressure, the nozzle and the pump A pressure sensor disposed in the piping tube between the pressure sensor and detecting a pressure in the piping tube, and a control unit that drives and controls at least the nozzle and the pump while referring to pressure information from the pressure sensor. An automatic dispensing device, wherein the control unit detects the clogging of the nozzle during the suction of the liquid, and after returning the liquid, cancels the positive pressure generated in the piping tube. An automatic dispensing device that controls the nozzle to perform a transfer operation after returning to atmospheric pressure.

[3] The method according to [1], wherein the control section once pulls out the nozzle from the liquid surface, raises the nozzle to a preset set distance, and returns the liquid to the same container. Automatic dispensing device as described. [4] The automatic dispensing device according to [2], wherein the control unit monitors the generation of the negative pressure in the piping tube sequentially even during the suction operation of the nozzle.

[0037]

As described above, according to the automatic dispensing apparatus of the present invention, the following effects can be obtained as described based on a plurality of embodiments and modifications. According to the automatic dispensing apparatus of the present invention, for example, even if the nozzle is clogged with a separating material or fibrin contained in the sample during aspiration of the sample at a medical site, the serum or the like remaining in the nozzle is removed from the sample tube. Can be prevented from being contaminated with other samples by being scattered or scattered, or contaminating the inside of the dispensing apparatus with the samples.

Therefore, according to the present invention, even when a nozzle or a pipe becomes clogged during a dispensing operation, an automatic dispensing operation that can safely and promptly process a sample to be dispensed by an appropriate return operation. A device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram schematically showing a configuration of an automatic dispensing apparatus as a first embodiment of the present invention.

FIGS. 2A and 2B show vertical movement of a nozzle when aspirating a sample by an automatic dispensing apparatus according to an embodiment of the present invention, wherein FIG. 2A shows an operation when a liquid level is detected, and FIG. (C) is a diagram showing the operation at the time of detecting the separation material, (d)
(F) is a diagram showing the operation at the sample return position.

FIG. 3 is a schematic configuration diagram schematically showing the configuration of an automatic dispensing apparatus according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing a dispensing operation procedure of the automatic dispensing device of the present invention.

FIG. 5 is a graph showing a change in pressure in a pipe accompanying a dispensing operation in the automatic dispensing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Dispensing nozzle, 2 ... Piping tube, 3 ... Pump, 4 ... Pressure sensor, 7 ... Serum layer, 8 ... Separation material layer, 9 ... Blood cell layer, 10 ... Three-way valve, 50 ... Control part, 101 ... Pump side 101: Nozzle side valve, 101: Atmospheric side valve, 200: State when liquid level is detected, 201: State when serum is sucked, 202: State when separating material is detected, 203a to 203c: Sample return position S10 to S90: processing steps in the dispensing process.

Claims (4)

[Claims] 1. A nozzle for sucking and discharging a liquid in a container, a piping tube connected to the nozzle, a pump connected to the nozzle and the piping tube for pressurizing and depressurizing, and a nozzle for the nozzle and the pump. A pressure sensor disposed in the piping tube between the two to detect a pressure in the piping tube, and a control unit that drives and controls at least the nozzle and the pump while referring to pressure information from the pressure sensor. An automatic dispensing device, wherein the control unit detects the clogging of the nozzle during the suction of the liquid, the nozzle to a predetermined position with respect to the liquid level in the container of the liquid An automatic dispensing device, wherein the liquid is returned to the container by moving the liquid. 2. A nozzle for sucking / discharging a liquid in a container, a piping tube connected to the nozzle, a pump connected to the nozzle and the piping tube for pressurizing / depressurizing, and a nozzle for the nozzle and the pump. A pressure sensor disposed in the piping tube between the pressure sensor and detecting a pressure in the piping tube; and a control unit that drives and controls at least the nozzle and the pump while referring to pressure information from the pressure sensor. An automatic dispensing device, wherein the control unit detects the clogging of the nozzle during suction of the liquid, cancels the positive pressure generated in the piping tube after returning the liquid, and increases the pressure. An automatic dispensing device, which controls so as to perform the transfer operation of the nozzle after returning to the atmospheric pressure. 3. The control unit according to claim 1, wherein the control unit withdraws the nozzle once from a liquid surface, raises the nozzle to a preset set distance, and returns the liquid to the same container. Automatic dispensing device as described. 4. The automatic dispensing apparatus according to claim 2, wherein the control unit monitors the generation of the negative pressure in the piping tube sequentially even during the suction operation of the nozzle.