JPH10232238A - Dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dispenser comprising a dispensation head fixed to the output part of a reciprocal driver, and an ultrasonic sensor fixed downward to the side part of the dispensation head in which a pipet chip mounted on the dispensation head is prevented from coming into collision against a reaction container upon erroneous operation of the ultrasonic sensor in the measurement of distance. SOLUTION: An ultrasonic sensor 400 is connected with a controller 19 comprising a memory 17 storing a limit distance corresponding to the distance to the bottom of a recess made in a reaction container. After executing a procedure for measuring the distance to the liquid level in a specific hole of the reaction container delivering a reagent, the distance to the liquid level thus measured is compared with a limit distance stored in the memory 17. When the distance to the liquid level exceeds the limit distance, the limit distance is employed as the distance to the liquid level in the dispensation operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispensing apparatus for dispensing and diluting liquids (hereinafter, collectively referred to as reagents) such as reagents and specimens.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 1, a dispensing apparatus is constructed by attaching a dispensing head (3) having a pipette tip (6) projecting downward to an output portion of a reciprocating drive (1). The dispensing head (3) is moved by the operation of the reciprocating drive (1).
After moving to the position above (7), pipette tip (6)
The reagent is discharged from a hole into a hole (71) recessed in the surface of the reaction vessel (7).

When dispensing a reagent into each hole (71) of a reaction vessel (7) set on a dispensing table (10), a control device (not shown) is used.
Controls the reciprocating drive (1) to bring the dispensing head (3) close to the hole (71) of the reaction vessel (7), and the pipette tip (6)
The reagent inside is discharged to the hole (71). When diluting or mixing the reagent, another reagent has already been injected into the hole (71), and the reagent dropped from the pipette tip (6) is brought into contact with the liquid surface of the reagent in the hole (71). Then, the reagent is discharged by releasing the surface tension. At this time, pipette tip
(6) When the reagent itself comes into contact with the reagent in the hole (71), the reagent adhering to the pipette tip (6) is mixed into another reagent in the next dispensing step. It is necessary to discharge the reagent at a position slightly floating above the liquid surface.

When the reagent is diluted or mixed as described above, the dispensing head (3) is lowered and the pipette tip is
(6) is brought as close as possible to the surface of the reagent in the hole (71) of the reaction vessel (7). However, since the level of the reagent varies among the holes (71), Each time, it is necessary to measure the liquid level of the reagent and adjust the height position of the pipette tip (6). At this time, the measurement of the liquid level of the reagent requires an accuracy of about 0.1 mm.

In terms of accuracy of distance measurement, it is advantageous to use a laser measuring device. However, in this case, a laser beam is applied to the reagent, so that a transparent reagent or a reagent causing a photochemical reaction is used. Is not applicable. Therefore, an ultrasonic sensor (400) is attached to the side of the dispensing head (3) to measure the distance of the reagent to the liquid surface, and the measured value is fed back to the control of the reciprocating drive (1). Is being done.

In the distance measurement by the ultrasonic sensor (400), an ultrasonic wave is transmitted from the ultrasonic sensor (400) toward the object to be measured, and the ultrasonic wave reflected back from the object to be measured is returned to the ultrasonic sensor. At (400), the distance to the measurement target is measured based on the time measurement from transmission to reception of the ultrasonic wave.

[0007]

As described above, the height position of the dispensing head is controlled based on the distance measurement by the ultrasonic sensor. However, if a malfunction occurs in the distance measurement for some reason, If the dispensing operation is continued based on the measurement result, the pipette tip (6) may be damaged. For example, if the measurement result exceeds the distance to the bottom of the hole (71) of the reaction vessel (7), the reciprocating drive
The control device of (1) uses the tip of the pipette tip (6) as the target position when lowering the dispensing head (3).
In order to set a position at which the pipette tip (6) falls below the bottom surface of the hole (71) of (7), the tip of the pipette tip (6) is moved downward by the lowering of the bottom of the hole (71) of the reaction vessel (7). And the tip is bent, making it impossible to dispense. or,
There is a possibility that the dispensing head (3) or the like may be damaged by an impact when the pipette tip (6) collides with the reaction vessel (7).

An object of the present invention is to provide a dispensing apparatus in which even if a malfunction occurs in the distance measurement, there is no possibility that the tip of the pipette tip collides with the reaction vessel.

[0009]

A dispensing apparatus according to the present invention comprises:
At the output of the reciprocating drive, a dispensing head for sucking and discharging the liquid is attached, and on the side of the dispensing head, a distance sensor for measuring the distance to the object to be measured is attached facing downward. A control device for controlling the operation of the reciprocating drive device is connected to the distance sensor. Here, the control device includes a data storage unit storing a limit distance corresponding to a distance to a bottom surface of the plurality of holes formed in the reaction container to which the liquid is to be discharged, and a reaction for discharging the liquid. A first control unit for executing a procedure for measuring a distance to a liquid surface of a specific hole of the container, a liquid surface distance obtained by an operation of the first control unit, a limit distance stored in a data storage unit, When the liquid level distance exceeds the limit distance, the second control unit executes the dispensing operation with the limit distance as the liquid level distance.

[0010] In the above dispensing apparatus of the present invention, the data storage section stores, as the limit distance, the distance to the bottom surface of the plurality of holes recessed in the reaction vessel or a distance slightly smaller than the distance. Have been. In the dispensing operation, first, a distance to a liquid surface of a specific hole of the reaction container from which the liquid is discharged is measured. Here, in a state where no other liquid is injected into the hole of the reaction container and the liquid is empty, the distance to the bottom surface of the hole is measured. Thereafter, when shifting to the dispensing operation, the measured liquid level distance is compared with the limit distance stored in the data storage unit. here,
When the liquid level distance does not include an error, the liquid level distance does not exceed the limit distance. Therefore, a normal dispensing operation is performed based on the measured liquid level distance.

On the other hand, when the liquid level distance includes an error and the liquid level distance exceeds the limit distance, the dispensing operation is executed with the limit distance as the liquid level distance. Therefore, even if the tip of the pipette tip may be immersed in the liquid of the reaction vessel, it is possible to avoid a situation in which the tip of the pipette tip falls further below the bottom of the hole of the reaction vessel, and the pipette tip collides with the reaction vessel. Is avoided. As a result, a dispensing operation is performed. If the data storage unit stores, as the limit distance, a distance smaller than the distance to the bottom of the plurality of holes formed in the reaction container, the tip of the pipette tip may be immersed in the liquid of the reaction container. Can be minimized.

In a specific configuration, the data storage unit further stores a second limit distance corresponding to a distance to an upper surface of the reaction container from which the liquid is to be discharged, and the second control unit further includes:
The liquid level distance obtained by the operation of the first control unit is compared with the second limit distance stored in the data storage unit, and when the liquid level distance falls below the second limit distance, the second limit distance is set.
The dispensing operation is performed with the limit distance of the liquid level as the liquid distance.

According to this specific configuration, when an error is included in the liquid level distance and the liquid level distance falls below the second limit distance,
The dispensing operation is performed with the second limit distance as the liquid level distance. Therefore, the dispensing operation can be performed with the tip of the pipette tip as close as possible to the reaction container, and a normal dispensing operation can be realized regardless of a malfunction in distance measurement.

[0014]

According to the dispensing apparatus of the present invention, even if a malfunction occurs in the distance measurement, there is no possibility that the tip of the pipette tip collides with the reaction vessel, and the dispensing operation can be performed. It is.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. As shown in FIG.
The dispensing apparatus of the present invention includes an X-axis drive mechanism (1) on a dispensing table (10).
1) A reciprocating drive (1) comprising a Y-axis drive mechanism (12) and a Z-axis drive mechanism (13) is installed, and a dispensing head (3) is attached to an output portion of the reciprocal drive (1). Together with the dispensing head
An ultrasonic sensor (400) is attached to the side of (3). Thus, the dispensing head (3) and the ultrasonic sensor (400) move integrally in three axial directions. The dispensing head (3) includes a nozzle (not shown) connected to a plunger mechanism (not shown), and a pipette tip (6) is detachably fitted to the nozzle.

As shown in FIG. 2, a cylindrical piece (401) having a circular cross section is vertically attached to an ultrasonic wave emitting portion of the ultrasonic sensor (400). The inner diameter of the cylindrical piece (401) is formed to be the same as the inner diameter D of the smallest hole, for example, 7 mm, among holes formed in various containers described later. The length of the tubular piece (401) is, for example, 60 mm.

The reciprocating drive (1) and the ultrasonic sensor (40)
0) is connected to a control device (19) shown in FIG. The control device (19) is an arithmetic processing circuit that performs predetermined arithmetic processing described later on the measurement data obtained from the ultrasonic sensor (400).
(16), a memory (17) for storing various data necessary for arithmetic processing and arithmetic processing results, and a control circuit (18) for controlling the reciprocating drive (1) according to the arithmetic processing results With

As shown in FIG. 1, a chip holder (61), a reagent container (74) and a reaction container (7) are respectively set at predetermined positions on a dispensing table (10). On the surface of the reagent container (74),
A plurality of holes (75) for injecting a reagent to be inhaled into the pipette tip (6) are formed in a recess. On the surface of the reaction vessel (7), a plurality of holes for discharging the reagent in the pipette tip (6) are provided.
(71) is recessed.

In the data stored in the memory (17), the distance from a predetermined height position to the bottom of the hole (71) of the reaction vessel (7) is stored in advance as a limit distance Hlimit. I have.

In the dispensing operation, the reciprocating drive (1) is controlled to move the dispensing head (3) and the ultrasonic sensor (400). First, the tip holder on the dispensing table (10) is moved. After attaching the pipette tip (6) contained in (61), the reagent injected into the hole (75) of the reagent container (74) is sucked into the pipette tip (6). Next, dispensing head (3)
And the ultrasonic sensor (400) is moved to a position above the reaction vessel (7), and the pipette tip is inserted into the hole (71) of the reaction vessel (7).
Discharge the reagent in (6).

At this time, first, the reagent already injected into the hole (71) of the reaction vessel (7) by the ultrasonic sensor (400) is used.
The distance to the liquid surface (liquid surface distance) in (52) is measured. In this case, as shown in FIG. 2, the opening of the tube piece (401) is
The openings of (71) are brought as close as possible, and the openings are made to face each other on the same axis. In this state, the ultrasonic sensor (40
When the ultrasonic waves are emitted from (0), the ultrasonic waves are guided to the inner peripheral surface of the tubular piece (401), and are not diffused, but are diffused into the holes of the reaction vessel (7).
(71). Then, the ultrasonic wave reflected on the liquid surface of the reagent is guided again to the inner peripheral surface of the tubular piece (401), and returns to the ultrasonic sensor (400). The measurement data obtained by the ultrasonic sensor (400) is used for controlling the height position of the dispensing head (3) by the control device (19) shown in FIG.

FIG. 4 shows a procedure for operating the reciprocating drive (1) based on the measurement result by the ultrasonic sensor (400). First, in step S1, the sensor output is fetched. In step S2, the limit distance Hlimit stored in the memory and the liquid surface distance H derived from the sensor output are compared in magnitude, and the liquid surface distance H is limited. It is determined whether the distance is greater than the distance Hlimit.
If the determination is yes, the liquid level distance H is replaced with the limit distance Hlimit in step S3, and step S3 is performed.
The operation shifts to the dispensing operation 4. On the other hand, when it is determined NO in step S2, the process shifts to step S4 to execute a dispensing operation based on the measured liquid surface distance H.

In the dispensing operation, the tip of the pipette tip (6) attached to the dispensing head (3) is held above the liquid level of the reagent (52) as shown in FIG. 0.6mm
At the height of At this time, even if the liquid level distance H includes an error and the liquid level distance H exceeds the limit distance Hlimit, the limit distance Hli is determined by the procedure of FIG.
Since the dispensing operation is performed with mit as the liquid surface distance, even if the tip of the pipette tip may be immersed in the reagent of the reaction container, the pipette tip does not drop below the bottom of the hole of the reaction container. Can be avoided and collision of the pipette tip is avoided.

Thereafter, the reagent in the pipette tip (6) is transferred to the reaction vessel by the operation of a plunger mechanism (not shown).
Discharge into the hole (71) of (7). At this time, pipette tip (6)
The reagent discharged from the reactor is in the form of drops,
By contacting the liquid surface of the reagent (52) in (71) and releasing the surface tension, the reagent drops onto the reaction vessel (7).

As described above, according to the dispensing apparatus of the present invention, even if a malfunction occurs in the distance measurement, there is no possibility that the pipette tip collides with the reaction vessel, so that the dispensing operation can be performed. . In addition, it is possible to avoid a situation where the dispensing head is damaged.

The description of the above embodiments is for the purpose of describing the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof.
In addition, the configuration of each part of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims. For example, the distance to the upper surface of the reaction vessel (7) is stored in the memory (17) as a second limit distance, and the measured liquid level distance is smaller than the second limit distance in the dispensing operation. At this time, the dispensing operation can be performed with the second limit distance as the liquid level distance. As a result, even if there is a malfunction in the distance measurement, a normal dispensing operation can be realized with a higher probability.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of a dispensing device according to the present invention.

FIG. 2 is a cross-sectional view illustrating a state of distance measurement by an ultrasonic sensor.

FIG. 3 is a block diagram illustrating a configuration of a control system.

FIG. 4 is a flowchart showing a procedure executed at the time of a dispensing operation.

FIG. 5 is a diagram illustrating a reagent discharging step using a pipette tip.

[Explanation of symbols]

 (1) Reciprocating drive (3) Dispensing head (6) Pipette tip (61) Tip holder (7) Reaction vessel (71) Hole

Claims (2)

[Claims] A liquid is sucked into an output section of a reciprocating drive,
In a dispensing apparatus in which a dispensing head to be discharged is attached, a distance sensor for measuring a distance to a measurement object is attached to a side of the dispensing head in a downward direction, and the distance sensor includes a reciprocating device. A control device for controlling the operation of the driving device is connected, and the control device stores a limit distance corresponding to a distance to a bottom surface of the plurality of holes formed in the reaction container from which the liquid is to be discharged. A data storage unit, a first control unit that executes a procedure for measuring a distance to a liquid surface of a specific hole of a reaction vessel into which liquid is discharged, and a liquid surface obtained by the operation of the first control unit A second control unit that compares the distance with the limit distance stored in the data storage unit and executes a dispensing operation with the limit distance as the liquid level distance when the liquid level distance exceeds the limit distance. Dispensing device. 2. The data storage unit further stores a second limit distance according to a distance to an upper surface of a reaction container from which a liquid is to be discharged, and the second control unit further operates by the operation of the first control unit. The obtained liquid level distance is compared with the second limit distance stored in the data storage unit, and when the liquid level distance is smaller than the second limit distance, the second limit distance is dispensed as the liquid level distance. The dispensing device according to claim 1, which performs an operation.