JPH0128461Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to cleaning a dispensing nozzle in an automatic biochemical analyzer or the like.

A nozzle for dispensing a highly viscous sample such as blood cannot avoid contamination due to sample adhesion on the inner and outer walls of the nozzle, so it must be thoroughly cleaned before aspirating a different sample.

For this reason, various methods have been used to clean the inner and outer walls of the nozzle, but after cleaning, a small amount of the previous sample or cleaning solution remains on the tip of the dispensing nozzle, preventing the suction of the next sample. Sometimes, as a result of their contamination, the accuracy of dispensing deteriorates and the accuracy of measurement deteriorates. In addition, in the above-mentioned analyzers and the like, in particular, it is necessary not to reduce the dispensing efficiency, so the cleaning must be performed without stopping the dispensing operation of the nozzle.

This idea solves the above problems, and
It was devised to meet the above requirements,
After cleaning the dispensing nozzle, no previous sample or cleaning solution remains on the nozzle tip, and
The present invention aims to provide a new dispensing device that can automatically clean the inner wall of the nozzle during a short period of time while returning the dispensing nozzle from the sample discharge position to the sample suction position.

In this invention, for such purpose, the cleaning liquid is discharged from the nozzle when the nozzle returns from the sample discharge position to the sample suction position, and the discharged cleaning liquid is removed by suction at the tip of the nozzle. In this case, since the amount of sample liquid adhering to the outer wall of the nozzle is much smaller than the amount of sample liquid adhering to the inner wall of the nozzle, the sample liquid is squeezed out using an appropriate means such as a squeezing rubber.

In other words, this device moves the dispensing nozzle horizontally between the sample suction position and the sample discharging position, and also moves the dispensing nozzle relative to the sample container and reaction vessel in both these positions to aspirate and discharge the sample. In a dispensing device which is configured to move up and down and is further provided with a mechanism for distributing and discharging cleaning liquid through the dispensing nozzle through a switching tip, a vacuum suction pipe is provided to suck in the cleaning liquid discharged from the nozzle from outside the nozzle, and the The suction tip of the suction tube is attached to the side of the nozzle tip at the nozzle's horizontal movement position so that it can follow the movement only in the horizontal movement direction, and the cleaning liquid is discharged when the nozzle returns from the sample discharge position to the sample suction position. The dispensing device is characterized in that the discharged cleaning liquid is suctioned and removed by the vacuum suction tube.

Hereinafter, the specific configuration of this invention will be explained based on the drawings.

FIG. 1 is a schematic explanatory diagram showing an example of the dispensing device according to the invention, and FIG. 2 is an operational explanatory diagram of its cleaning operation.

In these figures, reference numeral 1 denotes a syringe-type sample dispenser, which sucks and discharges a sample liquid from a dispensing nozzle A by driving its plunger 1'. In this case, the sample dispenser 1 sucks in an appropriate amount of sample liquid, for example, 30μ, from the sample container 2, and discharges a specified amount of sample liquid, for example, 10μ, into the reaction container 3. , the remaining sample liquid is discharged together with the cleaning liquid.

Reference numeral 4 denotes a cleaning pump which sucks in cleaning liquid 6 through a switching tank 5 and discharges it to the dispensing nozzle A through the switching socket 5. In this case, in order to improve the dispensing efficiency, the cleaning liquid 6 is sucked while the dispensing nozzle A moves from the sample suction position _P1 to the sample discharging position _P2 , and the cleaning liquid 6 is discharged from the dispensing nozzle A. is performed during the return from the sample discharge position _P2 to the sample suction position _P1 .
6' is a cleaning liquid container containing the cleaning liquid 6.

The dispensing nozzle A has a holding arm 7 that holds it.
It is caused to move horizontally between the sample suction position _P1 and the sample discharge position _P2 , and is also caused to move vertically at the respective positions _P1 and _P2 in order to suck and discharge the sample liquid. In this case, the dispensing flow path A' from the dispenser 1 to the dispensing nozzle A is as follows:
The dispensing nozzle A is formed flexibly to allow movement of the nozzle A, and the dispensing nozzle A is formed of a glass tube or the like so that the sample liquid adhering to the outer wall of the nozzle can be squeezed out with a squeezing rubber 8 or the like. is being used.

B is a vacuum suction tube that aspirates the sample liquid, washing liquid, etc. discharged from the dispensing nozzle A at its nozzle tip, and its suction tip B' is connected to the dispensing nozzle A.
The nozzle A is attached to the side of the nozzle tip at the horizontal movement position so that it can follow the nozzle A only in the horizontal movement direction. i.e. suction tip
B' is positioned on the side of the top dead center position of the nozzle tip by a retainer 9 that holds this and the squeezing rubber 8 together, and is moved horizontally as one unit with this nozzle A. It is being done.

This squeezing rubber 8 is inserted through the outer wall of the dispensing nozzle A and is positioned at the horizontal movement position of the tip of the nozzle. It is designed to be squeezed out automatically. Therefore, in order to aspirate the strained sample liquid as well, the suction tip B' is attached to the lower surface of the straining rubber 7, in particular, on the side of the nozzle tip positioned in the horizontal movement position. are located adjacent to each other.

The terminal end of the suction tube B is connected to a reduced pressure tank T, and the inside of the reduced pressure tank T is evacuated by a vacuum pump P, and the strained sample liquid is discharged from the nozzle A. The cleaning liquid, sample liquid, etc. that are present are suctioned and removed from the suction tip B'. In this case, the aspirated sample liquid, washing liquid, etc. are stored in the vacuum tank T, and the suction tube B
is formed to be flexible in order to allow movement of its suction tip B'.

Next, the operation of this embodiment device will be explained.

First, in the initial state, the holding arm 7 and the holder 9 are positioned at the sample suction position _P1 , and the tip of the dispensing nozzle A is positioned at its horizontal movement position. That is, dispensing nozzle A
The tip of is housed in the squeezing rubber 8 (see FIG. 2a). From this state, the holding arm 7 first descends to insert the nozzle tip into the sample container 2, and then the dispenser 1 shown in FIG. (see figure b). When this suction is completed, the holding arm 7 raises the nozzle to its horizontal movement position. At this time, the sample liquid adhering to the outer wall of the nozzle A is squeezed out by the squeezing rubber 8 and collected on the lower end surface of the squeezing rubber 8 (second
(see figure c). Subsequently, the holding arm 7 and the holder 9 move horizontally as one to the sample discharge position _P2 . During this period of movement, the switching pot 5 switches to the cleaning liquid suction side, and then the cleaning pump 4 operates to suck in a predetermined amount of cleaning liquid, for example 150 microns of cleaning liquid. The vacuum pump P also operates at the same time, and the sample liquid collected on the bottom surface of the straining rubber 8 is sucked into the tip.
Aspirate from B′. By this, for example, even if the liquid at the tip of the dispensing nozzle A is not drained properly and the sample liquid forms a bead and adheres to the nozzle tip, this will be removed together with the sample liquid collected on the lower surface of the squeezing rubber 8. is removed by suction, and the next discharge amount of the sample liquid is made more accurate, thereby improving the measurement accuracy of the analyzer.

Next, the holding arm 7 and the holder 9 move to the sample discharge position P ₂
When it stops at , the holding arm 7 descends to insert the nozzle tip into the reaction container 3, and then the dispenser 1 is activated to dispense only a specified amount of the previously aspirated sample liquid. (See Figure 2 d). When such ejection is completed, the holding arm 7 pulls the nozzle up to the horizontal movement position, and then the holding arm 7 and the holder 9 return together to the initial sample suction position _P1 . During this time, first, the vacuum pump P operates, and then the dispenser 1 and the cleaning pump 2 operate simultaneously, and the sample liquid left in the nozzle A and the cleaning liquid already sucked by the cleaning pump 2 are combined. While discharging it from the nozzle tip, it is removed by suction with suction tube B (Fig. 2 e)
reference). In this case, the discharge flow rate and flow rate of the cleaning liquid etc. are configured to be extremely small compared to the amount of air sucked in by the suction pipe B, the flow rate, etc. It is sucked into the suction tube B without falling from the bottom surface. For example, as a vacuum pump P, 2/min (33ml/sec)
When using one with a discharge capacity of can. Also,
Since such cleaning can be completed in a very short time, it is possible to increase the moving speed of the nozzle A to the sample suction position _P1 , and also to reduce the distance between the sample suction position _P1 and the sample discharge position _P2 . can be shortened as much as possible, thus improving dispensing efficiency.

Thereafter, such operations are repeated to repeatedly dispense the sample liquid and wash the nozzle.

As explained above, when cleaning the dispensing nozzle, excess sample and cleaning liquid are removed by suction at the nozzle tip before being discharged from the nozzle tip, so cleaning liquid, etc. adheres to the nozzle tip after cleaning. As a result, the accuracy of dispensing and measurement can be improved, and the inner wall of the nozzle can be cleaned while returning the dispensing nozzle from the sample discharge position to the sample suction position. Therefore, the dispensing efficiency can be greatly improved compared to conventional devices. In addition, since the sample liquid that adheres to the nozzle tip when the nozzle is immersed in the sample liquid can be removed by suction, it is possible to prevent an increase or decrease in the dispensed amount due to poor liquid drainage. This has effects such as being able to improve the measurement accuracy of the analyzer.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the dispensing device according to the invention, and FIG. 2 is an explanatory diagram illustrating, in particular, the cleaning operation of the dispensing nozzle of the dispensing device according to the invention. A...Dispensing nozzle, B...Reduced pressure suction tube, B'...
... Suction tip, P ₁ ... Sample suction position, P ₂ ... Sample discharge position, V ... Vertical movement direction, H ... Horizontal movement direction, 2 ... Sample container, 3 ... Reaction container, 4 ...
...Cleaning pump, 5...Switching pump, 6...Cleaning liquid.

Claims (1)

[Scope of utility model registration request] The dispensing nozzle is moved horizontally between the sample suction position and the sample discharging position, and the dispensing nozzle is moved horizontally between the sample container and the sample container in order to aspirate and discharge the sample at both positions.
In a dispensing device that moves up and down with respect to the reaction container and is equipped with a mechanism that allows the dispensing nozzle to circulate and discharge the cleaning liquid through a switching tip, vacuum suction is used to suck the cleaning liquid discharged from the nozzle from outside the nozzle. A tube is provided, and the suction tip of the suction tube is attached to the side of the nozzle tip at the nozzle's horizontal movement position so that it can follow the movement only in the horizontal movement direction, and the cleaning liquid is moved from the sample discharge position of the nozzle to the sample suction position. A dispensing device characterized in that the dispensing device is configured to discharge the cleaning liquid upon return to the pipe, and the discharged washing liquid is suctioned and removed by the vacuum suction tube.