JPH087113B2 - Total amount sampling method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for dispensing a total amount, and more particularly to an automatic dispensing apparatus, which is an improvement of a dispensing method and apparatus for withdrawing a sample in the uppermost layer of a container into which a sample is separated. Regarding

[0002]

2. Description of the Related Art A dispensing device for dispensing a sample is known, and is used, for example, as a device for distributing a blood sample collected from a human body into a plurality of containers.

Generally in a blood test, as shown in FIG.
The test tube 62 containing the separating agent 12 having an appropriate specific gravity and viscosity and the collected whole blood 10 is centrifuged, and the supernatant serum 14 is mainly used for the test. Here, it is preferable that the separating agent 12 used has a specific gravity intermediate between those of the serum 14 and the blood cells 16 and a viscosity extremely higher than those of the serum 14 and the blood cells 16. Therefore, as shown in FIG. 5, after centrifugation, the serum 14, the separating agent 12, and the blood cells 16 are separated in this order from the upper layer.

Conventionally, in order to obtain only the serum 14 after centrifugation, the test tube 62 was manually tilted as shown in FIG. 6 and the whole amount of the serum 14 was transferred to another test tube 62 '. In addition, carefully separating all the serum volume is
This is because multiple items can be effectively tested with a small blood collection amount.

However, when only the serum 14 is manually transferred, there is a limit to the processing capacity of the work,
In addition, there is a problem that workers often come into direct contact with the sample, which may cause infection. Furthermore, there is a problem that the patient samples are exchanged when the operator makes a mistake in transferring the samples, and accurate test results cannot be obtained.

Therefore, in recent years, transfer by an automatic dispensing device has been put into practical use.

[0007]

However, in the case of using the automatic dispensing device, if the tip of the nozzle tip comes into contact with the separating agent during suction, if it is left as it is, the separating agent will remain on the tip of the nozzle tip. It is sucked and the tip is blocked. As a result, there is a problem in that the required amount cannot be aspirated or the aspirated sample cannot be ejected due to clogging with the aspirated separating agent.

Therefore, in the current automatic dispensing device,
It has a function of detecting clogging of the nozzle tip, and a function of preliminarily estimating the serum amount by an optical sensor and then stopping suction before the nozzle tip comes into contact with the separating agent.

However, in any case, about 300 to 600 μl of serum remained in the test tube, and the serum could not be used effectively.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a total amount withdrawing and dispensing method for sucking almost all amount of serum without closing the tip of the nozzle tip, and an apparatus therefor. It is to be.

[0011]

In order to achieve the above object, the invention according to claim 1 uses a suction means to suck the uppermost sample from a container in which a plurality of samples having different viscosities are separated in layers. In the dispensing method for sucking, a suction stop step of sucking the uppermost layer sample by the suction means and stopping suction immediately before sucking the second layer immediately below the uppermost layer sample; A discharging step of discharging a part of the sample of the uppermost layer, a raising step of raising the suction means by a predetermined amount from the stop position in the suction stopping step, and a raising step of the uppermost layer from the rising position in the raising step. A re-aspirate step of re-aspirateing the sample,
It is characterized by having.

[0012] In a second aspect of the present invention, in a dispensing apparatus for aspirating an uppermost layer sample from a container in which a plurality of samples having different viscosities are separated in layers, a suction means for aspirating the sample, When a pressure detection unit connected to the suction unit and detecting a pressure change of the suction unit and the suction unit sucks the sample in the uppermost layer while monitoring the pressure detection unit and detects a sudden pressure change, The suction stop means for stopping the suction of the suction means, the partial discharge means for discharging a part of the sample of the uppermost layer sucked by the suction means after performing the suction stop means, and the suction means There is a raising means for raising a predetermined amount from the suction stop position, and a re-sucking means for re-sucking the uppermost layer sample by the suction means from the position raised by the raising means. It is characterized in.

[0013]

According to the first and second aspects, the suction is stopped immediately before sucking the second layer immediately below the uppermost sample, and a part of the uppermost sample sucked by the suction means is discharged. However, since the suction means is lifted by a predetermined amount from the previous stop position, the tip of the suction means will not be blocked even if the second layer once enters the suction means.

Further, since the sample in the uppermost layer is re-sucked by the suction means from the previously raised position, almost the entire amount of the sample in the uppermost layer can be sucked without sucking the second layer.

Further, according to the second aspect of the present invention, since the pressure detecting means is connected to the suction means and detects the pressure change of the suction means, the tip position of the suction means is detected by the pressure change. be able to. Therefore, it is possible to detect that the tip of the suction means is in contact with the second layer.
Do not aspirate layers.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the external appearance of an automatic dispensing apparatus 30 to which the total amount sampling and dispensing method according to the present invention is applied.
FIG. 1 is a perspective view thereof. In addition, this automatic dispensing device 30
In the present Example, the collected whole blood is centrifuged to separate it into a serum component and a blood cell component, and only the serum component is dispensed.

A nozzle portion 32 for sucking a blood sample, which is shown in the center of the drawing, is held by an XYZ robot 34, and the nozzle portion 32 is movable three-dimensionally.

FIG. 2 is a cross-sectional view of the main part of the nozzle part 32. The nozzle part 32 is composed of a nozzle base 35 and a disposable chip (hereinafter referred to as a chip) 36 which constitutes a nozzle chip. . That is, in the dispensing device of the present embodiment, disposable nozzle tips are used. In addition, this chip 36
The tip of the nozzle base 35 is press-inserted into the upper opening of the nozzle base 35. By fitting the tip of the nozzle base 35 into the upper opening of the tip 36 in this manner, the tip 36 is securely fixed to the nozzle base 35. Is done. A small hole 36a is formed at the lower end of the tip 36, and serum or the like is sucked or discharged from the small hole 36a. The tip 36 is made of, for example, hard plastic, and the nozzle base 35 is made of metal.

In FIG. 1, the XYZ robot 34 is used.
X drive unit 34x, Y drive unit 34y, and Z drive unit 3
4z, and an elevator section 38 having a nozzle section 32 is connected to the Z drive section 34z so as to be vertically movable.
The elevator section 38 has a limit switch 40 that functions as a jamming sensor or the like, and this limit switch 40 detects an upward external action force applied to the nozzle section 32. The nozzle portion 32 for ejecting the diluent is fixedly arranged on the Z drive portion 34z. One end of an air hose 44 is connected to the nozzle portion 32, and the other end of the air hose 44 is connected to a cylinder 46 that functions as a suction / discharge pump.

Between the cylinder 46 and the nozzle portion 32,
Pressure sensor 5 for measuring the internal pressure in the air hose 44
4 are connected. The signal from the limit switch 40 is sent to the apparatus main body via the signal cable 56.

Test tube rack 60 mounted on the dispensing table 58
A plurality of test tubes 62 containing blood samples after being subjected to the centrifugal separation process are erected and held in the tube. That is, as shown in FIG. 5, the test tube 62 contains a blood sample in which the components of the serum 14 and the components of the blood cells 16 are vertically separated. In addition, a discharge container 66 to which one component of the blood sample is transferred is provided on the dispensing table 58.

In the automatic dispensing apparatus 30 of this embodiment, since the nozzle tip is disposable, that is, it is a disposable type, a tip discard tray 74 is provided for sequentially exchanging a new tip and discarding the used tip. .

Therefore, according to the automatic dispenser 30 described above, the components of the serum 14 can be sucked by the tip 36 of the nozzle 32 and transferred to another container. Of course, this dispensing device can be used in addition to the dispensing of the blood sample, and various applications are possible.

FIG. 3 is a block diagram showing the schematic construction of the dispensing apparatus of this embodiment. The pump is composed of a piston 76 and a cylinder 46, and the inner volume of the cylinder 46 is changed by advancing and retracting the piston 76, and the suction pressure or the discharge pressure due to this is transmitted to the tip 36 of the nozzle portion 32 via the air hose 44. Then, the blood sample is sucked and discharged. The internal pressure of the air hose 44 is detected by the pressure sensor 54, the sensor signal is amplified by the DC amplifier 78, and then A is passed through the limiter circuit 80.
It is sent to the / D converter 82. Here, the limiter circuit 80 is a protection circuit that suppresses excessive input. The A / D converter 82 converts the sensor signal into a digital signal and sends it to the control unit 84.

The control unit 84 is composed of, for example, a computer, and controls the internal volume of the cylinder 46 and X.
The YZ robot 34 is controlled. In the present embodiment, the control unit 84 monitors the internal pressure of the air hose 44, in particular, every predetermined time, and when the internal pressure of the air hose 44 suddenly changes to a negative pressure, that is, the separating agent 12 causes the chip 36 to flow.
When it contacts the tip of the tip, the piston 76 is controlled to stop the suction by the tip 36, and then part of the serum 14 in the tip 36 is promptly discharged. Further, the control unit 8
4 controls the XYZ robot 34 to raise the tip 36 by a predetermined amount from the previous suction stop position, and controls the dispensing operation so that the serum 14 is sucked again from the raised position.

Next, a concrete example of the total amount withdrawing method adopted in the above automatic dispensing apparatus 30 will be described.

FIG. 4 shows the automatic dispensing apparatus 30 shown in FIG.
The total withdrawal process is shown. In this example,
At the same time when the suction operation is started, the pressure sensor 54 constantly monitors the internal pressure of the air hose 44. It should be noted that the contact of the separating agent 12 or the like with the tip 36 indicates that the air hose 4
The method of detecting the internal pressure level of No. 4 is the same as the method disclosed in Japanese Patent Application Laid-Open No. 2-184762 filed by the inventors of the present application.

In FIG. 4, in step 100 (“step” is abbreviated as “S” in the figure), the tip 36 is mounted on the nozzle base 35 and the test tube 62 containing the blood sample separated by the XYZ robot 34. Position the tip 36 above. In step 101, so-called liquid level detection is performed when the chip 36 is lowered in the z-axis direction. This liquid level detection is performed by monitoring the internal pressure of the air hose 44 with the pressure sensor 54, and the control unit 84 causes the tip of the tip 36 to reach the liquid level when the internal pressure of the air hose 44 suddenly changes. Make sure that.

In step 102, suction of the uppermost serum 14 is performed. That is, pull out the piston 76,
By increasing the internal volume of the cylinder 46 and making the internal pressure of the cylinder 46 negative, the serum 14 is taken into the chip 36. At this time, while the liquid level is being detected, the chip 36
Is lowered to aspirate the serum 14.

In step 103, when the internal pressure of the air hose 44 suddenly becomes negative when sucking the required amount of serum 14, the control unit 84 causes the tip 36 to suck the separating agent 12 in the lower layer of the serum 14. It is judged that it has begun, and the piston 76
And the operation of the XYZ robot 34 is stopped, and the chip 36
Stop sucking and lowering.

Then, in step 104, step 1
Immediately after the stop of 03 (preferably from sudden change in internal pressure to 50
The piston 76 is pushed out within a time (msec) to discharge a part (for example, about 20 to 30 μl) of the serum 14 in the tip 36. Then, the XYZ robot 34 raises a predetermined amount (for example, 1 to 2 mm) in the z-axis direction. It is sufficient to raise the tip 36 to such an extent that the tip of the tip 36 is located slightly below the liquid surface of the serum 14. Simultaneously performing the operations of partially discharging the serum 14 and raising the tip 36 is most effective in preventing the tip end clogging of the tip 36 by the separating agent 12.

In step 105, the piston 76 is withdrawn in the position raised in step 104, and the serum 14 remaining in the tip 36 in step 103 is removed.
In step 104, the partially discharged serum 14 is taken in.

In step 106, when the controller 84 confirms a sudden change in the internal pressure of the air hose 44, it is determined that the suction of air has started after the suction of the serum 14, and the suction operation is terminated.

At this time, the serum 1 remaining in the test tube 62
The amount of 4 is about 50 to 100 μl, which is extremely small as compared with the residual amount (300 to 600 μl) in the conventional apparatus. Therefore, the blood serum 14 that has been collected can be effectively used.

In step 107, the XYZ robot 34
Thus, the tip 36 is raised in the z-axis direction, and the serum 14 is prepared to be transferred to the discharge container 66.

After this, the chip 36 is mounted on the XYZ robot 3
4, and the serum 14 is discharged to the discharge container 66. Then, after ejection, it is moved to the chip disposal tray 74 and discarded.

The above operation is repeated for the number of specimens.

[0039]

As described above, according to the present invention,
Stop aspiration just before aspirating the separating agent directly below the serum sample, and discharge a part of the aspirated serum from the nozzle tip, so pressurize the inside of the nozzle tip that became negative pressure just before the blockage. You can Therefore, even if the separating agent once enters the nozzle tip, the tip of the nozzle tip is not blocked. Further, since the nozzle tip is raised by a predetermined amount from the previous stop position, suction of the separating agent can be avoided.

Since the serum is re-sucked by the nozzle tip from the previously raised position, almost the whole amount of serum can be sucked without sucking the separating agent.

Further, since the pressure detecting means is connected to the nozzle tip and indirectly detects the pressure change of the nozzle tip, the tip position of the nozzle tip can be detected by the change of the pressure. Therefore, the contact of the tip of the nozzle tip with the separating agent can be detected, and the separating agent is not sucked.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of a dispensing device to which a total amount sampling and dispensing method according to the present invention is applied.

FIG. 2 is a sectional view showing a sectional view of a main part of a nozzle portion 32.

FIG. 3 is a block diagram showing a schematic configuration of the dispensing device shown in FIG.

FIG. 4 is an explanatory diagram showing a total amount withdrawal process of the dispensing apparatus shown in FIG.

FIG. 5 is an explanatory view showing a step of centrifuging a blood sample to separate each component into layers.

FIG. 6 is an explanatory diagram showing a step of manually transferring only a serum component from a blood sample after separation.

[Explanation of symbols]

 12 Separation Agent 14 Serum 16 Blood Cell 30 Automatic Dispensing Device 32 Nozzle Section 34 XYZ Robot 36 Disposable Chip 54 Pressure Sensor 62 Test Tube 84 Control Section

Continuation of front page (56) Reference JP-A-57-133350 (JP, A) JP-A-61-202165 (JP, A) JP-A-2-184762 (JP, A)

Claims (2)

[Claims] 1. A dispensing method in which a sample in the uppermost layer is sucked by a suction means from a container in which a plurality of samples having different viscosities are separated in layers, wherein the sample in the uppermost layer is sucked by the suction means, A suction stopping step of stopping suction immediately before sucking the second layer immediately below the upper layer sample; a discharging step of discharging a part of the uppermost layer sample sucked by the suction means; A total amount withdrawn, characterized by having a raising step of raising a predetermined amount from a stopping position in the stopping step, and a re-sucking step of re-sucking the sample in the uppermost layer by the suction means from the rising position in the raising step. Note method. 2. A dispensing device for sucking a sample in the uppermost layer from a container in which a plurality of samples having different viscosities are separated in layers, and a suction means for sucking the sample, and a suction means connected to the suction means. A pressure detection unit that detects a pressure change of the suction unit; and a sample in the uppermost layer is sucked by the suction unit while being monitored by the pressure detection unit, and the suction of the suction unit is stopped when a rapid pressure change is detected. Suction stop means, partial discharge means for discharging a part of the sample of the uppermost layer sucked by the suction means after performing the suction stop means, and raising the suction means by a predetermined amount from the suction stop position. And a re-aspiration means for re-aspirating the sample in the uppermost layer by the aspiration means from the position elevated by the aforesaid elevation means. Share dispensing device.