JP2007093537A - Liquid sample dispenser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid sample dispenser for dispensing a liquid sample with accuracy. <P>SOLUTION: The liquid sample dispenser comprises a nozzle 2 for sucking or discharging a liquid sample; a cylinder 5 connected to the nozzle via a flexible tube 3; a plunger 6 that reciprocates in the cylinder and makes the internal pressure act; an actuator 7 for allowing the plunger to reciprocate; an actuator drive section 8 for driving the actuator; and a control section 9 for controlling the actuator drive section. The control section 9 has a potentiometer storage section 11 for storing the potentiometer value at the discharge position of the plunger, thus ordering a value obtained by adding the potentiometer value stored in advance to a thrust command, based on the discharge operation pattern of the actuator to be given to an actuator drive section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid sample dispensing apparatus for accurately dispensing a liquid sample into a reaction container.

2. Description of the Related Art Conventionally, there has been proposed a liquid sample dispensing apparatus that keeps the liquid surface of a liquid sample in a suction holding unit constant and precisely discharges the liquid sample (see, for example, Patent Document 1).
FIG. 6 is a configuration diagram showing a main part of a conventional liquid sample dispensing apparatus.
The liquid sample dispensing apparatus 211 has a dispensing probe 212 as a suction holding unit, a syringe 213 as a pressure generating unit, and a stepping motor 214 for driving a syringe. A motor driving unit 215 that drives the stepping motor 214 and a control unit 216 are provided.

This liquid sample dispensing apparatus operates as follows.
First, the syringe 213 is driven to suck, and the cleaning water 229 and the liquid sample 230 are sequentially sucked into the probe 212. As shown in FIG. 7A, an air layer 231 is interposed between the cleaning water 229 and the liquid sample 230. The suction amount of the liquid sample 230 is taken as a total amount of the required dispensing amount for each reaction container 219 so that the plurality of reaction containers 219 can be continuously dispensed, and is sucked without an air layer. Next, the syringe 213 is driven to discharge, and the liquid sample 230 in the probe 212 is discharged into the n reaction containers 219 (only two are shown) by a predetermined amount. The position of the liquid level 234 at the tip of the probe 212 is as shown in FIG.
The liquid sample 230 discharged to each reaction container 219 is further divided in time, and is discharged twice (initial discharge and final discharge). Each of the divided n divided samples is a solution in which an appropriately different amount of the divided sample is dispensed into a desired volume (for example, a reaction vessel or a dilution vessel) at sequential timing or irregular timing. In the time division of the liquid sample, the drive pulse for the first discharge and the drive pulse for the final discharge are output separately based on the command of the control unit 216. FIG. 7C shows a state where the (n-1) th dispensing has been completed.
Thus, the conventional liquid sample dispensing device keeps the liquid surface of the liquid sample in the suction holding unit constant and precisely discharges the liquid sample.
JP-A-6-341999 (5th page, FIGS. 1 and 2)

  However, the conventional liquid sample dispensing apparatus can discharge the liquid sample while keeping the liquid surface of the liquid sample in the suction holding unit constant, but the discharge of the plunger in the connected syringe connected to the motor. There is a problem that the discharge amount of the liquid sample may change depending on the sliding resistance (frictional force) at the position.

  The present invention has been made in view of such a problem, and a thrust command based on a discharge operation pattern of an actuator is used for a sliding resistance (friction force) at a discharge position of a plunger in a syringe stored in advance. An object of the present invention is to provide a liquid sample dispensing apparatus that can dispense a liquid sample with high accuracy by using the value added to the operation command.

In order to solve the above problems, the present invention is configured as follows.
The invention described in claim 1 includes a nozzle that sucks or discharges a liquid sample, a cylinder connected to the nozzle through a flexible tube, a plunger that reciprocates in the cylinder and applies an internal pressure, and the plunger. An actuator that reciprocates, an actuator driving unit that drives the actuator, and a control unit that controls the actuator driving unit, and discharges the liquid sample sucked and held by the nozzles to a plurality of reaction containers one by one. In the liquid sample dispensing apparatus for dispensing, the control unit includes a sliding resistance storage unit that stores a sliding resistance value at the discharge position of the plunger, and the thrust command based on the discharge operation pattern of the actuator is set in advance in the thrust command. A value obtained by adding the stored sliding resistance value is used as an operation command to the actuator drive unit. Than is.
In the invention according to claim 2, the discharge position is set in advance.
According to a third aspect of the present invention, the discharge position is an arbitrary place obtained by calculation in advance based on a plurality of discharge positions.

According to the first aspect of the present invention, the value obtained by adding the sliding resistance value stored in advance to the thrust command based on the discharge operation pattern of the actuator is used as the operation command to the actuator drive unit. The liquid sample can be accurately discharged regardless of the frictional force (sliding resistance) at the discharge position.
According to the second aspect of the present invention, since the discharge position is set in advance, the liquid sample can be discharged accurately regardless of the frictional force (sliding resistance) at the discharge position of the plunger in the syringe.
According to the third aspect of the present invention, since the discharge position is obtained in advance by calculation based on a plurality of discharge positions and is set at an arbitrary position, the friction force (sliding resistance) at the discharge position of the plunger in the syringe is used. The liquid sample can be discharged more accurately.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of a liquid sample dispensing apparatus showing Embodiment 1 of the present invention.
In the figure, 1 is a liquid sample dispensing device, 2 is a nozzle, 3 is a flexible tube, 4 is a syringe, 5 is a cylinder, 6 is a plunger, 7 is an actuator, 8 is an actuator drive unit, and 9 is a control unit. Note that 12 is a liquid sample container for supplying a liquid sample, 13 is a reaction container for discharging the liquid sample, and 14 is a liquid sample.
The liquid sample dispensing apparatus 1 includes a nozzle 2 for sucking and holding a liquid sample, a flexible tube 3 for flowing the liquid sample, a syringe 4, an actuator 7 connected to a plunger 6, an actuator driving unit 8 and a control unit 9. The control unit 9 mainly controls the actuator driving unit 8 and includes a CPU 10 and a sliding resistance storage unit 11 that stores the sliding resistance (frictional force) of the plunger 6 in the syringe 4.
The nozzle 2 is a hollow body with a thin tip and is maintained in the vertical direction. Then, the liquid sample 14 in the liquid sample container 12 is sucked, the liquid sample 14 is discharged into the reaction container 13, and cleaning water in a cleaning water container (not shown) is also sucked and discharged.
The syringe 4 is arranged at a fixed position of the liquid sample dispensing apparatus 1 and is connected to the nozzle 2 via the flexible tube 3. When the plunger 6 is moved to the rear of the syringe 4, the liquid sample 14 is sucked to increase the volume in the syringe 4. When the plunger 6 is moved to the front of the syringe 4, the liquid sample 14 is discharged to decrease the volume in the syringe 4.
The actuator 7 is capable of moving the plunger 6 in the syringe 4 up and down and is driven by the actuator driving unit 8.
The actuator driving unit 8 is connected to the control unit 9 and drives the actuator 7 based on the operation command output from the control unit 9.
The control unit 9 includes a CPU 10 and a sliding resistance storage unit 11, and controls the actuator driving unit 8 so that the nozzle 2 discharges a liquid sample 14 (sample or reagent).
The CPU 10 inputs necessary information regarding various liquid samples 14 based on the number of samples read from the identification mark displayed on the liquid sample container 12 or the like and a desired analysis item. The actuator driving unit 8 is controlled so as to correspond to the quantity and the dispensing order. Further, the CPU 10 controls the actuator driving unit 8 for the washing water and / or air layer suction operation as necessary.
The sliding resistance storage unit 11 stores the sliding resistance (frictional force) at the discharge position of the plunger 6 in the syringe 4. For this reason, the control unit 9 defines the coordinate system of the plunger 6 in the syringe 4, and sets the coordinate when the plunger 6 moves to the tip of the syringe 4 to 0, and the arbitrary coordinate when the plunger 6 moves to the rear of the syringe 4. p. Then, the sliding resistance (friction force) f (p) at the determined discharge position p of the plunger 6 is measured in advance using a force gauge or the like. The measurement results are shown in FIG. FIG. 2 is a diagram showing the sliding resistance (friction force) at the discharge position of the plunger 6 in the syringe.

Next, the operation of this embodiment will be described with reference to FIGS.
FIG. 3 is a diagram illustrating a flow of the actuator control unit, and FIG. 4 is a diagram illustrating a suction state of the nozzle.
(1) First, the sliding resistance (friction force) is stored (F0).
The sliding resistance (friction force) f (p) at a predetermined discharge position p in the syringe 4 measured in advance is stored in the sliding resistance storage unit (FIG. 2).
(2) Aspirate the washing water (F1).
When the plunger 6 in the syringe 4 is sucked and driven by the actuator 7, the cleaning water 15 in a cleaning water container (not shown) is sucked from the nozzle 2 (FIG. 4 (a)). Alternatively, cleaning water may be supplied to the flexible tube and the nozzle 2 from a pump (not shown) via a valve (not shown) and another flexible tube (not shown).
(3) Suction air (F2).
The plunger 6 in the syringe 4 is sucked and driven by the actuator 7, and the air 16 is sucked into the syringe 4 from the nozzle 2 (FIG. 4B).
(4) Aspirate the liquid sample (F3).
The actuator 6 sucks and drives the plunger 6 in the syringe 4 and sucks the liquid sample 14 in the liquid sample container 12 from the nozzle 2 (FIG. 4C).
(5) Discharge the liquid sample (F4).
The sum of the thrust command to the actuator 7 based on the discharge operation pattern and the sliding resistance (friction force) f (p) at the predetermined discharge position p of the plunger 6 in the syringe 4 stored in advance. As a new thrust command, the actuator 7 is driven to discharge the plunger 6 in the syringe 4 from the determined discharge position p, and the liquid sample 14 is discharged from the nozzle 2 to the reaction vessel 13 (FIG. 4D).
(6) Repeat (2) to (5) for each discharge.
Thus, in this embodiment, the sliding resistance (friction force) at the discharge position of the plunger 6 in the syringe 4 is stored in advance, and the value obtained by adding this sliding resistance is used as an operation command to the actuator drive unit. Therefore, the liquid sample can be discharged with high accuracy regardless of the sliding resistance (frictional force) at the discharge position of the plunger 6 in the syringe 4.
In this embodiment, the air suction amount, the liquid sample suction amount, and the discharge position are fixed, but these amounts may be obtained in advance based on experiments in accordance with the liquid sample discharge amount. In addition, it is assumed that the operator prepares the liquid sample container 12 and the reaction container 13 under the nozzle 2, but the control unit 9 synchronizes with the actuator 7 to the nozzle 2 or the liquid sample container 12 and the reaction container (not shown). A liquid sample may be automatically sucked and discharged by controlling a table or the like on which 13 is mounted. Further, a plurality of dispensed liquid samples may be sucked, and the liquid samples may be continuously discharged to the plurality of reaction vessels 13.
The difference between the present invention and Patent Documents 1 and 2 is that the sliding resistance (friction force) at the discharge position of the plunger 6 in the syringe 4 is stored in advance, and the value obtained by adding this sliding resistance is the actuator drive unit. It is a point to be an operation command to.

Since the configuration of the present embodiment is the same as that of the first embodiment, description thereof is omitted.
The frictional force (sliding resistance) f (p ₀ ) at a predetermined discharge position p ₀ of the plunger 6 in the syringe 4 is measured with a force gauge or the like in advance.

Next, the operation of this embodiment will be described.
(1) Memorize sliding resistance (frictional force) (F0).
The sliding resistance (friction force) f (p ₀ ) at one predetermined discharge position p ₀ in the syringe 4 measured in advance is stored in the sliding resistance storage unit.
(2) Washing water suction (F1), (3) Air suction (F2), (4) Liquid sample suction (F3) is the same as in Example 1.
(5) Discharge the liquid sample (F4).
The thrust command to the actuator 7 based on the discharge operation pattern and the sliding resistance (friction force) f (p ₀ ) at a predetermined discharge position p ₀ of the plunger 6 in the syringe 4 stored in advance. As a new thrust command, the plunger 6 in the syringe 4 is driven to discharge from a predetermined discharge position p ₀ by the actuator 7 and the liquid sample 14 is discharged from the nozzle 2 to the reaction vessel 13 ( FIG. 4 (d)).
(6) Repeat (2) to (5) for each discharge.
In this way, the dispensing actuator control unit 9 includes the sliding resistance memory unit, and the sliding resistance memory unit is connected to the dispensing actuator at a predetermined discharge position of the plunger in the syringe. Syringe that stores sliding resistance (frictional force) and that is connected to a dispensing actuator in which the dispensing actuator control unit 9 is stored in advance in a thrust command based on a discharge operation pattern of the dispensing actuator Since the value obtained by adding the sliding resistance (frictional force) at one determined discharge position of the plunger inside can be used as the operation command, the plunger at the predetermined discharge position of the plunger within the syringe is determined. A liquid sample can be discharged with high accuracy regardless of sliding resistance (frictional force).

Since the configuration of the present embodiment is the same as that of the first embodiment, description thereof is omitted. In the present embodiment, results obtained by measuring in advance a plurality of predetermined discharge positions and frictional forces of the plunger 6 are used.
Next, the operation of this embodiment will be described.
The operation of the control unit 9 is the same as the flow of FIG. In order for the controller 9 to accurately discharge a liquid sample, sliding resistance (frictional force) at a plurality of discharge positions p ₀ , p ₁ , p ₂ , p ₃ , and p ₄ of the plunger 6 in the syringe 4 in advance. ) F (p ₀ ), f (p ₁ ), f (p ₂ ), f (p ₃ ), f (p ₄ ) are measured with a force gauge or the like.

(1) Memorize sliding resistance (frictional force) (F0).
Sliding resistance (friction force) f (p ₀ ), f (p ₁ ), f (at a plurality of predetermined discharge positions p ₀ , p ₁ , p ₂ , p ₃ , p ₄ in the syringe 4 measured in advance. p ₂ ), f (p ₃ ), and f (p ₄ ) are stored in the sliding resistance storage unit.
(2) Washing water suction (F1), (3) Air suction (F2), (4) Liquid sample suction (F3) is the same as in Example 1.
(5) Discharge the liquid sample (F4).
Thrust command to the actuator 7 based on the discharge operation pattern and sliding at a plurality of predetermined discharge positions p ₀ , p ₁ , p ₂ , p ₃ , p ₄ of the plunger 6 in the syringe 4 stored in advance Add the resistance (frictional force) f (p ₀ ), f (p ₁ ), f (p ₂ ), f (p ₃ ), f (p ₄ ) as a new thrust command and use the actuator 7 The plunger 6 is driven to discharge from any one of a plurality of predetermined discharge positions p ₀ , p ₁ , p ₂ , p ₃ , p ₄ and discharges the liquid sample 14 from the nozzle 2 to the reaction vessel 13. (FIG. 4 (d)).
(6) Repeat (2) to (5) for each discharge.
As described above, the control unit 9 includes the sliding resistance storage unit, and the sliding resistance (frictional force) at a plurality of determined discharge positions of the plunger 6 in the syringe 4 connected to the actuator 7 is connected to the sliding resistance storage unit. ), And the control unit 9 slides at a plurality of determined discharge positions of the plunger 6 in the syringe 4 connected to the actuator 7 stored in advance in the thrust command based on the discharge operation pattern of the actuator 7. Since the value obtained by adding the dynamic resistance (frictional force) can be used as the operation command, the liquid sample can be accurately measured regardless of the sliding resistance (frictional force) at the specified multiple discharge positions of the plunger 6 in the syringe 4. Can discharge well.

  Since the configuration of the present embodiment is the same as that of the first embodiment, description thereof is omitted. The present embodiment is an example using a function of sliding resistance (friction force) at an arbitrary discharge position based on a plurality of discharge positions of the plunger 6 in the syringe 4.

Next, the operation of this embodiment will be described.
(1) Memorize sliding resistance (frictional force) (F0).
Sliding resistance (frictional force) f (p ₀ ), f (p ₁ ), f at a plurality of discharge positions p ₀ , p ₁ , p ₂ , p ₃ , p ₄ of the plunger 6 in the syringe 4 measured in advance Based on (p ₂ ), f (p ₃ ), and f (p ₄ ), the sliding resistance (friction force) f (p) at an arbitrary discharge position p of the plunger 6 is expressed by a curve approximation formula such as a spline curve. Functioned and stored in the sliding resistance storage unit.
(2) Washing water suction (F1), (3) Air suction (F2), (4) Liquid sample suction (F3) is the same as in Example 1.
(5) Discharge the liquid sample (F4).
The thrust command to the actuator 7 based on the discharge operation pattern was added to the sliding resistance (friction force) f (p) at an arbitrary discharge position p of the plunger 6 in the syringe 4 that was stored in advance as a function. As a new thrust command, the plunger 6 in the syringe 4 is driven to discharge from the arbitrary discharge position p by the actuator 7, and the liquid sample 14 is discharged from the nozzle 2 to the reaction vessel 13 (FIG. 4 (d)).
(6) Repeat (2) to (5) for each discharge.
Thus, the control unit 9 includes a sliding resistance storage unit, and the sliding resistance storage unit stores the sliding resistance (friction force) at the discharge position of the plunger 6 in the syringe 4 connected to the actuator 7, Value obtained by adding the frictional force (sliding resistance) at the discharge position of the plunger 6 in the syringe 4 connected to the actuator 7 stored in advance to the thrust command based on the discharge operation pattern of the actuator 7 by the control unit 9 Therefore, the liquid sample can be discharged with high accuracy regardless of the sliding resistance (friction force) at the discharge position of the plunger 6 in the syringe 4.

  In addition, since a liquid sample can be accurately discharged regardless of the sliding resistance (frictional force) at the discharge position of the plunger in the syringe, it can be applied to bio-related and medical-related devices that require suction and discharge.

It is a block diagram of the liquid sample dispensing apparatus which shows Example 1 of this invention. It is a graph which shows the relationship between the discharge position of the plunger in Example 1, and frictional force. FIG. 6 is a flowchart illustrating an operation of a control unit in the first embodiment. It is sectional drawing which shows the suction state of the nozzle of FIG. It is a graph which shows the relationship between the discharge position which shows Example 4 of this invention, and frictional force. It is a block diagram which shows the principal part of the conventional liquid sample dispensing apparatus. It is sectional drawing which shows the liquid level position of the liquid sample in a probe at the time of each dispensing of FIG.

Explanation of symbols

1, 211 Liquid sample dispenser
2 nozzles
3, 223 Flexible tube
4, 213 syringe
5, 220 cylinders
6 Plunger
7 Actuator
8 Actuator drive
9 Control unit
10, 226 CPU
11 Sliding resistance memory
12 Liquid sample container
13 Reaction vessel
14,230 Liquid sample
15, 229 Washing water
16 air
212 dispensing probe
212a Tip
214 stepper motor
215 Motor drive
216 Control unit
217 Probe transfer section
218 Sample container
219 reaction vessel
221 piston
222 Pressure chamber
224 slide body
225 thread
227 Time division part
231 Air layer
234 Liquid level

Claims (3)

A nozzle that sucks or discharges a liquid sample, a cylinder connected to the nozzle via a flexible tube, a plunger that reciprocates in the cylinder and applies an internal pressure, an actuator that reciprocates the plunger, and the actuator In a liquid sample dispensing apparatus that includes an actuator driving unit that drives and a control unit that controls the actuator driving unit, and discharges and dispenses the liquid sample sucked and held by the nozzles into a plurality of reaction containers. ,
The control unit includes a sliding resistance storage unit that stores a sliding resistance value at a discharge position of the plunger, and a value obtained by adding the previously stored sliding resistance value to a thrust command based on the discharge operation pattern of the actuator. Is an operation command to the actuator driving unit.   The liquid sample dispensing apparatus according to claim 1, wherein the discharge position is a preset location.   The liquid sample dispensing apparatus according to claim 1, wherein the discharge position is an arbitrary portion obtained by calculation in advance based on a plurality of discharge positions.

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