JPS6321140B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid dispensing device for automatically sucking and discharging liquid such as serum separated by centrifugation.

For blood tests at hospitals or medical examination centers, blood is collected from a human body and first separated into blood clots and serum by centrifugation, then only the serum is fractionated, and this fractionated serum is further tested. Samples are dispensed into different sample containers depending on the purpose. In this case, since the number of specimens is extremely large, it is desired to automatically perform such fractionation and dispensing of serum from the viewpoint of shortening blood test time and improving efficiency.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid dispensing device that can automatically and accurately separate and dispense liquids such as serum separated into layers by centrifugation. With the goal.

That is, the present invention comprises a tube with an open tip, a nozzle for suctioning and discharging a liquid to be sampled or dispensed, a suction means that communicates with the nozzle as appropriate via a switching valve, and a tube that connects the nozzle and the above. An air supply means equipped with a compressor that communicates appropriately through a switching valve, a pressure reducer interposed between the switching valve and the compressor, and an air supply means that connects the inner wall of the tube between the switching valve from the tip opening of the nozzle. The present invention provides a liquid sorting and dispensing device comprising at least a pair of electrodes provided apart from each other, and means for stopping suction by the suction means in response to electrical changes between the electrodes. .

The present invention will be described below with reference to an illustrated embodiment.

In the figure, numeral 1 denotes a nozzle with an opening at the tip for aspirating or dispensing the liquid to be dispensed, and is made of an insulating tube made of, for example, Teflon. This nozzle 1 is appropriately positioned by a drive device and optical detection means (not shown) so that its tip is located at the bottom of the serum layer 3 in the centrifuged blood collection tube 2. The positioning of the tip is
The nozzle may be moved up and down by an optical detection means provided at the tip of the nozzle, or the blood collection tube may be moved up and down by an optical detection means provided at the side of the blood collection tube. Reference numeral 4 denotes a washing water tank, which communicates with the nozzle 1 through a two-way solenoid valve V ₁ and a three-way solenoid valve V ₂ so that washing water can be appropriately sent to the nozzle 1 via a water pump 5. It's getting old. 6
is a vacuum pump, which connects to the nozzle 1 via a two-way solenoid valve V ₁ , three-way solenoid valves V ₂ and V ₃ as appropriate.
The nozzle 1 is designed to communicate with the blood collection tube 2, and the serum in the blood collection tube 2 is aspirated through the nozzle 1. An air trap 7 may be interposed between the vacuum pump 6 and the three-way solenoid valve, if necessary. 8 is a compressor, which includes a two-way solenoid valve V ₁ , a three-way solenoid valve V ₂ , V ₃ , V ₄
The serum sucked into the nozzle 1 can be pressed by air pressure and dispensed from the tip of the nozzle 1 into the sample cup. Note that a pressure reducer 9 may be provided on one of the branch paths between the compressor 8 and the solenoid valve _V4 to appropriately reduce the air pressure toward the nozzle 1 as required.

A pair of electrodes 10a and 10b are arranged on the inner wall of the tube on the electromagnetic valve V1 side slightly above the open end of the nozzle ₁ and spaced apart from each other. Furthermore, another pair of electrodes 1 is installed near the solenoid valve V ₁ upstream from this.
1a and 11b are arranged. These electrodes 10
a, 10b, 11a, and 11b detect electrical changes such as electrical resistance when serum is present between the electrodes and when serum is not present between the electrodes, and the drive of the vacuum pump 6 is automatically controlled accordingly. Furthermore, electrical changes between the electrodes may be detected by connecting the secondary side of the transformer to the electrodes, applying an alternating current voltage to the primary side, and detecting the current change. Furthermore, an electrode 10 is installed using a conductive tube (stainless steel pipe) at the tip of the nozzle.
It may also be a.

Next, operations for cleaning the inner wall of the tube circuit, aspirating serum from a blood collection tube, and dispensing into a sample cup using this liquid dispensing device will be explained.

[Washing process] First, the tip of nozzle 1 is moved by a drive device (not shown).
As shown in FIG. 2, it is inserted into the drain tank 12. Next, the two-way solenoid valve V ₁ and the three-way solenoid valve V ₂ are energized to communicate the nozzle 1 with the cleaning water tank 4 . Next, the water pump 5 is driven to flow the cleaning water into the nozzle 1. After washing the inside of nozzle 1 by passing water for a specified period, turn off the power to solenoid valve V ₂ ,
Connect the circuit to the compressor 8 side. The three-way solenoid valve _V3 is de-energized, the three-way solenoid valve _V4 is energized, the nozzle 1 and the compressor 8 are communicated through the line 13, and the compressor 8 is driven at the same time to supply air. The water droplets adhering to the inner wall of the nozzle 1 are scattered and dried, and the cleaning process is completed.

[Serum fractionation process]

First, the nozzle 1 is introduced into the blood collection tube 2 by a drive device (not shown). In this case, the nozzle 1 is positioned by optical means so that the tip of the nozzle 1 is located exactly at the bottom of the centrifuged serum 3 layer. 2-way solenoid valve V ₁ is energized, 3-way solenoid valve V ₂
is de-energized, and the three-way solenoid valve _V3 is energized to communicate the nozzle 1 and the vacuum pump 6 via the air trap 7. By driving the vacuum pump 6, the serum 3 is sucked into the nozzle 1.
At this time, a voltage is applied between the electrodes 10a and 10b, and the electrical resistance therebetween is measured. That is, when the serum 3 is filled between the electrodes 10a and 10b, the resistance value shows a certain level, but as the serum suction progresses and the serum in the blood collection tube 2 runs out, air enters the nozzle 1. Then, air intervenes between the electrodes 10a and 10b, causing a sudden increase in electrical resistance. This sudden change in electrical resistance is also controlled by a control device (not shown).
This allows the two-way solenoid valve to be detected.
The energization of V ₁ is stopped, and the suction drive by the vacuum pump is also stopped at the same time.

Note that if there is a large amount of serum to be collected and the serum is present between the electrodes 10a and 10b, and the serum also reaches between the electrodes 11a and 11b, the electrical resistance between the electrodes 11a and 11b Similarly, the control device senses the sudden change in the temperature, and stops the current supply to the two-way solenoid valve _V1 and the vacuum pump 4, thereby stopping the suction. This makes the serum 2
It can be prevented from flowing into the directional solenoid valve _V1 .

[Serum dispensing process]

First, in the same manner as in the previous step, the tip of the nozzle 1 is introduced into the sample cup 14 as shown in FIG. 3 by a driving device (not shown). Next, the two-way solenoid valve V ₁ is kept energized, and the three-way solenoid valve V ₂ ,
V ₃ and V ₄ are de-energized, and the nozzle 1 and compressor 8 are communicated via a pressure reducer 9. At the same time, if the compressor 8 is driven, weakly pressurized air flows into the nozzle 1 via the pressure reducer 9, and the serum 3 in the nozzle 1 is pushed out to the sample 14 by this air pressure. The amount of serum dispensed at this time can be controlled by adjusting the opening time of the two-way solenoid valve _V1 . After dispensing, immediately close the two-way solenoid valve _V1 , energize the three-way solenoid valve _V3 for a short time,
At the same time, when the two-way solenoid valve V ₁ is opened again, the pressure inside the nozzle 1 is reduced, and the serum adhering to the tip of the nozzle 1 is drawn back into the nozzle 1. After dispensing into the sample cup 14 is completed in this manner, dispensing into other sample cups can be performed by repeating the same operation as above.

As described above in detail, according to the liquid dispensing device of the present invention, cleaning of the nozzle, separation and dispensing of liquids such as serum can be performed automatically and accurately. It is possible to save labor and improve efficiency.

In addition, in the above embodiment, the solenoid valve above the nozzle 1
Although the explanation has been given on the case where two pairs of electrodes are provided on the V ₁ side, the electrodes 11a and 11b are connected to the nozzle 1.
It is also possible to omit this by making the length of the tube communicating with the tube sufficiently long, or conversely, in order to know the position of the aspirated liquid in more detail, three or more pairs of electrodes can be placed at appropriate positions. There is no problem even if it is provided in

Further, in the above embodiments, the case of separating and dispensing serum has been described, but it is clear that the apparatus of the present invention can also be used for separating and dispensing liquids other than serum.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the liquid dispensing device according to the present invention, Fig. 2 is a sectional view of main parts for explaining the cleaning process, and Fig. 3 is a main part for explaining the dispensing process. FIG. In the figure, 1... nozzle, 2... blood collection tube, 3... serum, 4... washing water tank, 5... water pump, 6
... Vacuum pump, 7 ... Air trap, 8 ... Compressor, 9 ... Pressure reducer, 10a, 10b,
11a, 11b...electrode, 12...drainage tank, 14
...sample cup.

Claims (1)

[Scope of Claims] 1. A nozzle consisting of a tube with an open tip for aspirating and discharging a liquid to be separated or dispensed, a suction means appropriately communicating with the nozzle via a switching valve, and the nozzle. an air supply means having a compressor that communicates with the switching valve as appropriate through the switching valve; a pressure reducer interposed between the switching valve and the compressor; and a tube between the switching valve and the opening at the tip of the nozzle. A liquid sorting and dispensing device comprising: at least a pair of electrodes provided on an inner wall at a distance from each other; and means for stopping suction by the suction means in response to an electrical change between the electrodes. 2. The liquid separating and dispensing device according to claim 1, wherein the suction means comprises a vacuum pump and an air trap, and the switching valve and the vacuum pump are communicated via the air trap. 3. The liquid separating and dispensing device according to claim 1, wherein the nozzle has an electrode having a tip made of a conductive material.