JPH05133851A - Dispensing apparatus - Google Patents

Abstract

PURPOSE:To enable highly-accurate calculations and fine control by providing a heating part and a heating temperature controlling part in a sucking/ discharging pipe part which has a pipette part at the front end thereof, with the rear end shut. CONSTITUTION:The amount of liquid sucked in a pipette part 2s is determined by the temperature difference in a sucking/discharging pipe part 2. Therefore, a control unit 18 operates the heating temperature Th and the cooling temperature Tc. The pipe 2 is heated to the temperature Th by a current supplied from a power feeding part 17. The pipette 2s is dipped in the liquid and cooled to the temperature Tc according to the compulsory air cooling. The pipette 2s is maintained at the temperature Tc. The liquid of the amount determined by the difference of the temperatures Th and Tc is sucked into the pipette 2s. Then, the pipette 2s is pulled up and the pipe 2 is heated to the temperature Tc or higher. Consequently, the sucked liquid is discharged outside to be dripped on a slide. At the sucking time, it is confirmed by a liquid amount sensor 20 whether the set amount of liquid is sucked. If the amount is too much or insufficient, it is so controlled that the temperature Tc is changed. The pipette 2s is exchangeable every time it is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispensing device suitable for inhaling and spotting a trace amount of liquid suitable for use in a biochemical analysis system or the like.

[0002]

In the field of biochemical analysis, generally 1 μm
In order to handle a small amount of liquid of about 1 liter, a dispensing device for inhaling and spotting with high precision is used.

FIG. 7 shows a conventional dispensing device 50. In the figure, reference numeral 51 is an intake / exhaust cylinder, which has a piston 52 slidable in the axial direction inside thereof, and a piston rod 53 connected to the piston 52 is an intake / exhaust cylinder 5.
1 to the outside from the rear end. In addition, the intake and exhaust cylinder 5
An inlet / outlet port 54 is provided at the front end of 1, and a detachable pipette 55 having a thin tip is attached to the inlet / outlet port 54. On the other hand, the piston rod 53 protruding to the outside has a threaded portion 56.
And the nut 57 is screwed into the ball screw mechanism 58. Also, the nut 57
A driven gear 59 is formed on the outer periphery of the drive gear 61 and meshes with a drive gear 61 provided on the output shaft of a rotary drive unit 60 having a servo motor, a speed reduction mechanism and the like built therein. Then, the rotation driving unit 60 is connected to the control unit 62.

Accordingly, the piston rod 53 is moved forward and backward by the operation of the rotary drive unit 60, and the pipette 55 sucks or discharges (spots) a liquid such as a test liquid or a reaction liquid, and the control unit 62 For example, the rotation speed sensor incorporated in the rotation drive unit 60 detects the rotation speed, and the position control of the piston rod 53 is performed based on the rotation speed sensor, so that the pipette 55 is inhaled or pipette 55.
Weigh the liquid draining from.

[0005]

However, the conventional dispensing device 50 has the following problems.

First, since a mechanical error due to backlash in a mechanical transmission mechanism such as a reduction mechanism and a ball screw mechanism becomes large, it is difficult to perform high-accuracy weighing and minute control.

Secondly, since a mechanical rotary drive unit and a transmission mechanism are used, the structure is complicated and the cost is increased, and the weight of the entire apparatus cannot be reduced.

Thirdly, when the pipette is replaced with a new pipette each time it is used, the replacement must be performed manually, so that the problem of contamination (contamination) cannot be avoided, and the work is also difficult. Be inefficient.

The present invention solves the problems existing in the prior art as described above, and it is possible to easily perform high-accuracy weighing and minute control, and to reduce the size, weight and cost of the device. It is an object of the present invention to provide a dispensing device that can perform pipette exchange easily and automatically.

[0010]

Dispensing device 1 according to the present invention
Is a suction / exhaust pipe part 2 that closes the rear end part 2r and has a pipette part 2s on the front end side, a heating part 3 for heating a part or all of the intake / exhaust pipe part 2, and a heating temperature of the intake / exhaust pipe part 2. The basic feature is that the control unit 4 for controlling is provided.

In this case, the pipette portion 2s can be constructed so as to be attachable to and detachable from the front end of the suction / exhaust pipe portion 2. Further, the heating part 3 can be formed by forming the intake / exhaust pipe part 2 from a conductive material and heating the intake / exhaust pipe part 2 by passing an electric current through the intake / exhaust pipe part 2. ..

Further, as an applied form, a continuous suction / discharge tube 7 and a closing mechanism 8 for forming a suction / discharge pipe section 2 whose front end side is a pipette section 2s by pressing and closing a middle position of the suction / discharge tube 7. And a cutter unit 9 for cutting the used pipette unit 2s, and a suction / discharge tube 7
Can be configured to be provided with the feeding mechanism unit 10 that sequentially feeds out in units of a predetermined length. As another application form, a continuous suction / exhaust tube 12 having blocking portions 11 at predetermined intervals.
And a cutter unit 9 that cuts a predetermined position of the suction / exhaust tube 12 to form the suction / exhaust pipe unit 2 whose front end side is the pipette unit 2s, and a feeding mechanism unit 10 that sequentially feeds the suction / exhaust tube 12 in units of a predetermined length. You can also do it.

[0013]

According to the dispensing apparatus 1 of the present invention, by heating a part or the whole of the intake / exhaust pipe part 2 by the heating part 3, the volume of the internal gas in the intake / exhaust pipe part 2 is expanded and cooled. As a result, the volume of the internal gas contracts. Since the rear end portion 2r of the suction / exhaust pipe portion 2 is closed, the liquid is sucked into the pipette portion 2s of the suction / exhaust pipe portion 2 when the volume of the internal gas is contracted, and the pipette portion 2s is expanded when the volume of the internal gas is expanded. The contained liquid is discharged to the outside. Therefore, by controlling the heating temperature of the intake / exhaust pipe section 2 by the control section 4 and varying the expansion amount or contraction amount of the internal gas, the liquid can be measured at the time of suction or discharge.

For example, as shown in FIG. 6, when the inner diameter D of the intake / exhaust pipe portion 2 is 0.5 mm, the volume change of the ideal gas in the range where the length L is 1 m is as follows. First, the equation of state of gas PV = nRT (where P: gas, V: volume, n: number of moles, R: Rydberg constant,
(T: temperature), P, n, and R are constant, so T
The change amount dT of V is proportional to the change amount DV of V and becomes dT∝dV. Therefore, P (V + dV) = nR (T + dT)
To obtain dV = nR (T + dT) / P−V = nRdT / P. Therefore, the volume V of the ideal gas is V = π (D / 2) ²
Since L = 196 μl, a volume change of 0.718 μl can be obtained with a temperature change of 1 K by calculating with the constants of n and R.

If the pipette portion 2s is detachably attached to the front end of the suction / exhaust pipe portion 2, the pipette portion 2s can be replaced each time it is used. Further, by using the continuous suction / exhaust tube 7, the used pipette section 2s is separated by the cutter section 9, and further the next new suction / exhaust pipe section 2 is drawn out by the feeding mechanism section 10. A new pipette section 2s can be used for each. As still another form, a continuous suction / exhaust tube 12 having blocking portions 11 at predetermined intervals is used and the cutter portion 9 is used.
By cutting the predetermined position of the suction / exhaust tube 12 with
The suction / exhaust pipe section 2 whose front end side is the pipette section 2s is formed, and further, after the pipette section 2s is used, the feeding mechanism section 10
The suction / exhaust tube 12 may be drawn out in a unit of a predetermined length by means of this.
s can be used.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, the structure of the dispensing apparatus 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The dispensing device 1 is equipped with a suction / exhaust pipe portion 2 which closes the rear end portion 2r and has a pipette portion 2s on the front end side. The intake / exhaust pipe part 2 is a thin tube made of a conductive material, and its substantial length is increased by, for example, forming a zigzag curve. Further, the pipette portion 2s is integrally formed of, for example, a transparent synthetic resin, and as shown in FIG.
The tip end is formed in a tubular shape with a small diameter, and the rear end is provided with an attachment / detachment portion 2h for attaching / detaching to / from the tip opening of the suction / exhaust pipe portion 2.

On the other hand, the intake / exhaust pipe section 2 is housed in a heat insulating case 15 or the like, and power supply cables 16p and 16n are connected to the rear end side and the front end side, respectively, and the other ends of the power supply cables 16p and 16n are connected to the power supply section ( Power supply part) 17. As a result, the heating unit 3 that heats by supplying a current from the power supply unit 17 to the intake / exhaust pipe unit 2 is configured. A control unit 18 detects the heating temperature of the intake / exhaust pipe section 2 by a temperature sensor 19 attached to the intake / exhaust pipe section 2, and the intake / exhaust pipe from the power supply section 17 so that the heating temperature reaches the set temperature. A control unit 4 that controls the magnitude of the current flowing through the unit 2 is configured. In this case, for example, 37 ℃
Since the resistance value of the intake / exhaust pipe section 2 in (1) is always a constant value, the temperature of the heating section 3 may be measured by passing a current through the intake / exhaust pipe section 2 and measuring the resistance value.
Therefore, at the time of temperature control, it suffices to adjust the current flowing through the intake / exhaust pipe section 2 to control the resistance value to be constant, and the temperature control can be performed without measuring the temperature.

Reference numeral 20 is a liquid amount sensor for detecting the amount of liquid to be sucked in or discharged. For example, a transmission type optical sensor can be used.

Next, the usage method and function of the dispensing apparatus 1 according to the first embodiment will be described.

First, the control unit 18 sets in advance the amount of liquid to be sucked into the pipette section 2s. Since the amount of liquid to be sucked is determined by the temperature difference in the suction / exhaust pipe part 2, the control unit 18 calculates the heating temperature Th and the cooling temperature Tc. As a result, the power supply unit 17 to the supply / discharge pipe unit 2
An electric current is passed through to heat to the heating temperature Th. Then, in this state, the pipette portion 2s is immersed in a liquid W (see FIG. 3) such as a test solution or a reaction solution, and is cooled to the cooling temperature Tc by forced air cooling by, for example, a fan or a freezing means, and is maintained at the same temperature. As a result, the liquid amount determined by the temperature difference between the heating temperature Th and the cooling temperature Tc is sucked into the pipette portion 2s. Next, if the pipette portion 2s is pulled up and moved to, for example, the slide Y (see FIG. 3) and the supply / discharge pipe portion 2 is heated to the heating temperature Tc or higher, the sucked liquid W is discharged from the pipette portion 2s to the outside. It can be discharged and spotted on the slide Y.

At this time, the amount of liquid to be sucked is set so that the liquid to be sucked is contained in the pipette portion 2s. Also,
At the time of suction, it is possible to confirm whether or not the set liquid amount has been sucked by the liquid amount sensor 20, and if there is an excess or deficiency, control is performed to change the cooling temperature Tc. On the other hand, the pipette part 2s
Can be replaced with a new pipette portion 2s by one use.

Next, the structure of the dispensing apparatus 1 according to the second embodiment of the present invention will be described with reference to FIG.

The dispensing apparatus 1 according to the second embodiment is configured such that a plurality of suction / discharge pipes 2 can be automatically supplied by using continuous suction / discharge tubes 7. The suction / exhaust tube 7 is a thin tube made of a flexible material such as silicon or Teflon, and is wound into a roll, for example. Further, the suction / discharge tube 7 is sequentially fed by the feeding mechanism section 10. The feeding mechanism section 10 includes guide plates 21, 22, 23 for guiding the suction and discharge tube 7, guide rollers 24,
A transfer roller mechanism including a drive roller 25 and an idle roller 26 for transferring the suction / discharge tube 7 is provided. The drive roller 25 is rotated by a rotary drive unit 30 using a servo motor. On the other hand, reference numeral 8 denotes a closing mechanism, which has a function of closing the midway position of the sucking and discharging tube 7 by pressing the midway position of the sucked and discharging tube 7 which is pushed vertically by the upper pusher 28 and the lower pusher 29. As a result, the intake / exhaust tube 7 located forward of the closed position in the feeding direction is attached to the intake / exhaust pipe section 2.
The closed position is the rear end 2r and the front end is the pipette part 2
s.

A heating tank 5 (heating section 3) for heating a part of the intake / exhaust pipe section 2 is arranged in front of the closing mechanism section 8 in the feeding direction. On the other hand, 9 is a cutter unit, which has a function of automatically cutting the used pipette unit 2s. Furthermore,
Reference numeral 31 is a liquid amount sensor configured in the same manner as the liquid amount sensor 20 and detects the amount of liquid sucked into the pipette portion 2s.

The closing mechanism section 8, the heating tank 5, the rotation driving section 30, the cutter section 9 and the liquid amount sensor 31 are connected to the control section 4.
Is connected to the control unit 32. The heating tank 5 is provided with a temperature sensor 33 for detecting the heating temperature of the intake / exhaust pipe section 2, and the temperature sensor 33 is connected to the control unit 32.

Next, the operation and usage of the dispensing device 1 according to the second embodiment will be described with reference to FIGS. 3 and 4.

First, the control unit 32 includes the rotary drive unit 30.
The suction / exhaust tube 7 is extended by a predetermined length by controlling the. FIG. 3 shows this state. Then, by controlling the closing mechanism section 8 to bring the upper pusher 28 and the lower pusher 29 close to each other as shown in FIG. 4, the middle position of the suction and discharge tube 7 is pressed and closed. As a result, the intake / exhaust pipe portion 2 is formed in front of the closed position. Next, by controlling the heating tank 5 and heating the intake / exhaust pipe part 2 to a preset heating temperature Th and cooling it to the cooling temperature Tc in the same procedure as in the first embodiment, the front end side of the intake / exhaust pipe part 2 is cooled. The liquid W can be sucked into the pipette portion 2s, and the liquid W can be discharged from the pipette portion 2s and spotted on the slide Y.

Thereafter, the cutter unit 9 is controlled to cut and separate the used pipette unit 2s, and the rotary drive unit 30 is controlled to move the suction / discharge tube 7 forward by the length of the cut-off pipette unit 2s. The new pipette section 2s can be set by feeding out. The liquid amount sensor 31, the heating unit 3
The control of the control unit 32 with respect to is performed as in the first embodiment.

In the second embodiment described above, a single continuous tube member is used as the intake / exhaust tube 7,
As shown in FIG. 5, a continuous suction / exhaust tube 12 having blocking portions 11 at predetermined intervals may be used. In this case, the cutter unit 9 causes the suction / exhaust tube 12 to move to a predetermined position,
Desirably, the suction / exhaust pipe section 2 whose front end side is the pipette section 2s can be formed by cutting the position behind the blocking section 11 and close to the blocking section 11. Therefore, the closing mechanism section 8 is unnecessary. However, when feeding out the suction / exhaust tube 12, it is necessary to extend in length units of the suction / exhaust pipe portion 2.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment,
The detailed configuration, shape, material and the like can be arbitrarily changed without departing from the scope of the present invention.

[0033]

As described above, the dispensing apparatus according to the present invention heats the suction / exhaust pipe portion having the pipette portion at the front end side closed and the suction / exhaust pipe portion partially or entirely heated. And a control unit for controlling the heating temperature of the intake / exhaust pipe unit, the following remarkable effects are achieved.

Since a mechanical error due to a mechanical transmission mechanism such as a speed reduction mechanism and a ball screw mechanism is eliminated, highly accurate weighing and minute control can be easily realized.

Since no mechanical rotation drive unit or transmission mechanism is required, the configuration can be simplified, the cost can be reduced, and the weight of the entire device can be reduced.

By providing a continuous suction / exhaust tube, a cutter section for cutting the used pipette section, and a feeding mechanism section for sequentially feeding out the suction / exhaust tube in units of a predetermined length, the pipette section can be easily exchanged and contamination can be prevented. It is possible to avoid problems and improve work efficiency.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of a dispensing device according to a first embodiment of the present invention,

FIG. 2 is an enlarged cross-sectional view of a pipette portion of the dispensing device,

FIG. 3 is a principle configuration diagram of a dispensing device according to a second embodiment of the present invention,

FIG. 4 is a cross-sectional view of an intake / exhaust tube closed by a closing mechanism of the dispensing device.

FIG. 5 is a sectional view of an intake / exhaust tube according to another embodiment of the dispensing device,

FIG. 6 is an explanatory view of the principle of the present invention,

FIG. 7 is a configuration diagram of a main part of a dispensing device according to a conventional technique,

[Explanation of Codes] 1 Dispensing device 2 Suction / exhaust pipe part 2r Rear end part 2s Pipette part 3 Heating part 4 Control part 5 Heating tank 7 Suction / exhaust tube 8 Closing mechanism part 9 Cutter part 10 Feeding mechanism part 11 Closing part 12 Suction / exhaust tube

Claims (6)

[Claims] 1. A suction / exhaust pipe section having a rear end closed and a pipette section on the front end side, a heating section for heating a part or all of the suction / exhaust pipe section, and a control for controlling a heating temperature of the intake / exhaust pipe section. Dispensing device characterized by comprising a section. 2. The dispensing device according to claim 1, further comprising a detachable pipette portion at a front end of the suction / exhaust pipe portion. 3. The dispensing apparatus according to claim 1, wherein the heating section is formed by forming the intake / exhaust pipe section from a conductive material, and heating the intake / exhaust pipe section by applying an electric current. 4. The dispensing apparatus according to claim 1, wherein the heating section is a heating tank for heating the intake / exhaust pipe section. 5. A continuous suction / discharge tube, and a closing mechanism section for forming a suction / discharge pipe section whose front end side is a pipette section by pressing and closing a middle position of the suction / discharge tube.
2. The dispensing device according to claim 1, further comprising a cutter unit for cutting the used pipette unit, and a feeding mechanism unit for sequentially feeding the suction and discharge tubes in units of a predetermined length. 6. A continuous suction / exhaust tube having blocking portions at predetermined intervals, a cutter portion for cutting a predetermined position of the suction / exhaust tube to form a suction / exhaust pipe portion whose front end side serves as a pipette portion, and a predetermined length for the suction / exhaust tube. The dispensing device according to claim 1, further comprising: a feeding mechanism unit that sequentially feeds in units.