JP2013057514A - Dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dispenser capable of achieving high-speed operation and the improvement of dispensation accuracy without deteriorating the dispensation accuracy by suppressing the squirt of a sample during the movement of a probe.SOLUTION: A liquid level position of a sample in a probe can be controlled without the deterioration of dispensation accuracy by adding a liquid-level controller 40 which can draw in fluid in a pipe. The fluid in the pipe is drawn in by the liquid level actuator during the time between after sample sucking operation and before sample discharging operation. The drawn fluid is restored before the discharge, so that the liquid level position of the sample in the probe is restored.

Description

  The present invention relates to a dispensing apparatus incorporated in an automatic analyzer or the like and used for dispensing a liquid sample such as a reagent or serum.

  In recent years, the market demand for automatic analyzers has increased the speed of tests aimed at increasing the number of tests per hour in order to reduce test costs, and dispensed volumes for reducing patient burden and reducing reagent usage. There is a small amount. Therefore, there is a demand for speeding up of the dispensing device that dispenses reagents and serum in the automatic analyzer and miniaturization. However, since the dispensing mechanism handles a liquid sample such as serum or reagent with an elongated probe at the end of the arm, a phenomenon may occur in which the sample scatters when operated at high speed. When the sample or reagent is scattered, the dispensing accuracy is deteriorated, and the ratio of the sample and the reagent is different from the set value, which has a problem of affecting the inspection accuracy.

  In the phenomenon that the sample scatters as described above, there are a case where the sample adheres to the side surface of the probe and the adhered sample scatters by an arm operation, and a case where the sample inside the probe is pushed out and scatters. In the former case, measures are taken by designing the material and shape of the probe or the operation at the time of pulling out so that the amount of adhesion is small. In the latter case, a countermeasure such as preventing dripping can be considered by setting the pressure in the pipe to a negative pressure as in Patent Document 1. Patent Document 1 discloses a method of preventing dripping by increasing the negative pressure of the piping system by driving the syringe pump when an abnormality such as air leakage occurs in the piping system of the dispensing device and the internal pressure of the piping changes. doing.

JP 2003-194835 A

  There is a problem that the sample jumps out from the tip of the probe and the sample that jumps out scatters, affecting the inspection accuracy. However, the sample jumping out during the operation of the dispensing device acts on the internal fluid as the probe moves. The influence of inertia force is large. Therefore, scattering of the sample tends to occur when the speed of the dispensing apparatus is increased.

  To solve the above problems, by driving the syringe pump and applying a negative pressure to the piping system as in the technique of Patent Document 1 described above, the liquid level of the sample at the tip of the probe is raised. Although it is possible to suppress popping out, it is not possible to discharge a set amount of sample due to the positioning error caused by backlash of the ball screw mechanism used in the syringe pump, and dispensing accuracy deteriorates when the sample is discharged. There's a problem.

  Therefore, an object of the present invention is to provide a dispensing apparatus that realizes high-speed operation and improved dispensing accuracy by suppressing the jumping of the sample during probe movement without deteriorating the dispensing accuracy. To do.

  Typical examples of the present invention include a probe that sucks and discharges a sample, a pipe connected to the probe, a pump that is connected to the pipe and changes the pressure in the pipe, and is arranged in the pipe. And a liquid level control device that controls the liquid level of the fluid filled in the liquid.

  In the dispensing apparatus of the present invention, in addition to the syringe pump that performs suction and discharge operations, by adding a liquid level control device that can draw in the fluid in the pipe, there is a backlash that becomes a problem when operating the syringe pump. The liquid level position of the sample in the probe can be controlled without being affected. During the period from the sample suction operation to the discharge operation, the fluid level in the pipe is drawn by the liquid level controller, so that the liquid level of the sample in the probe rises, and the liquid jumps out due to the movement of the probe. By preventing the scattering and returning the drawn fluid to the original state before discharge, the liquid level position of the sample in the probe is returned to the original, so that the dispensing accuracy is not affected.

  The same effect can be obtained when a pressure accumulator such as an accumulator that suppresses the pressure change in the pipe generated when the sample in the probe jumps out is added instead of the mechanism for drawing the fluid in the pipe. it can.

  With the configuration that can realize the method that suppresses the jumping of the sample from the probe of the dispensing device as described above, the deterioration of the dispensing accuracy due to the scattering of the sample can be reduced, and the high-speed operation and the dispensing accuracy can be improved. .

  According to the present invention, a dispensing apparatus capable of preventing high-speed operation and high dispensing accuracy by preventing the scattering of the sample by controlling the operation of the liquid surface position of the sample of the probe or the pressure change in the pipe. Can provide.

It is a figure which shows the structure of the apparatus regarding the dispensing apparatus of the conventional automatic analyzer. It is a figure which shows the relationship between the motor instruction | command acceleration of a dispensing apparatus, the amount of sample pop-outs, and the motor instruction | command acceleration and an acceleration sensor measured value. It is a figure which shows the control block of the conventional dispensing apparatus. It is a figure which shows an example of the control block of the dispensing apparatus in this invention. It is a figure which shows the velocity waveform at the time of a probe raise, the acceleration sensor measured value, and the pressure change in piping. It is a figure which shows the flow of the dispensing operation | movement in this invention. It is a figure which shows an example of the liquid level operation device using the piezoelectric actuator in this invention. It is a figure which shows an example of the liquid level operation device using the electromagnetic actuator in this invention. It is a figure which shows an example of the animal pressure device which suppresses the pressure change in this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. In the following description, serum will be described as an example of the sample. However, the same applies to the case of handling reagents.

  FIG. 1 is a diagram showing a configuration of a device related to a dispensing device of a conventional automatic analyzer. The dispensing apparatus 10 has a structure capable of moving the arm up and down and rotating the arm, and has a probe 11 that sucks and discharges a sample at the tip of the arm. The dispensing apparatus 10 sucks the serum with the sample disk 21 in which the test tubes storing the serum are arranged, and discharges the serum with the reaction disk 22 that mixes the reagent and the serum and confirms the reaction. Between the sample disk 21 and the reaction disk 22, the dispensing device 10 moves the arm up and down and rotates the arm to position the probe at the target position. The probe 11 includes a pressure sensor 31 that measures the pressure in the pipe 50, a syringe pump 32 that performs suction and discharge operations, an electromagnetic valve 33 that opens and closes the pipe 50, and system water filled in the pipe 50. A gear pump 34 that feeds out the inside of the probe 11 and a tank 35 that stores system water are connected by piping. As described above, the syringe pump 32 is configured by a ball screw mechanism, and performs suction and discharge operations from the probe 11 by driving a stepping motor.

  Fig.2 (a) is a figure which shows the relationship with the quantity of the sample which protruded from the probe 11 when changing the motor command acceleration of a dispensing apparatus. In order to operate the dispensing device at high speed, it is necessary to increase the motor command acceleration of the dispensing device. However, increasing the motor command acceleration increases the amount of sample protruding from the probe. It becomes easy to scatter and will deteriorate dispensing accuracy. When the commanded acceleration of the motor is increased, the acceleration acting on the probe 11 also increases, so that the inertial force acts on the fluid in the probe 11 as described above, and the sample jumps out from the probe 11.

  FIG. 2B is a diagram showing a relationship with the vertical acceleration generated in the structure near the probe 11 when the motor command acceleration is changed in the ascending operation of the arm. Although the characteristics differ depending on the structure of the drive motor and the probe, the acceleration command measured value tends to amplify the motor command acceleration. The acceleration acting on the probe 11 can be calculated from the motor command acceleration by measuring the relationship as shown in FIG. 2B and the transfer characteristic from the drive motor to the probe 11.

  FIG. 3 is a diagram showing a control block of a conventional dispensing apparatus. The dispensing apparatus 10 includes a motor for performing the respective operations in order to perform the vertical movement and rotation of the arm as described above, and the probe 11 is connected to the pipe 50 inside the arm of the dispensing apparatus. A dispensing device control unit 300 for controlling the dispensing device is driven by a dispensing sequence processing unit 301 that manages an operation sequence of the dispensing device, a dispensing operation control unit 302 that executes a dispensing operation, and a motor. Motor control unit 303 that gives a command, syringe control unit 304 that gives a drive command to the motor of the syringe pump, pressure detection input unit 305 that detects the pressure in the pipe by a signal from the pressure sensor 31, and information on the dispensing sequence Are dispensed sequence data 306, a dispensing operation parameter 307 that retains motor drive parameters, and a higher-level communication processing unit 310 that communicates with the higher-level computer 320. The dispenser motor and the syringe pump 32 motor are driven by giving a drive command from the dispenser controller 300 via the motor driver 330. The pressure sensor is mainly configured to detect abnormalities in the piping, and in a dispensing device that handles serum, the dispensing device controller monitors the clogging of the serum in the probe. .

  Hereinafter, the present invention will be described using Examples 1 and 2.

  FIG. 4 is a diagram showing a control block of the dispensing device according to the present invention. A liquid level control device 40 is added to the pipe between the dispensing device 10 and the syringe pump 32, and the liquid level operation unit 401 in the dispensing device control unit 300 causes the fluid in the pipe to draw the sample liquid in the probe. Control the surface position. More specifically, the pipe is filled with a fluid, and the dispensing apparatus control unit 300 indirectly controls the liquid level position of the sample by controlling the liquid level of the fluid.

  With the above configuration, the dispensing device control unit 300 performs the drawing of the fluid in the pipe via the liquid level operation unit 401 after completion of the suction operation from the dispensing operation control unit 302. Drive. As the fluid in the pipe is drawn into the liquid level control device, the liquid level of the sample inside the probe 11 is raised by the volume of the drawn fluid. Before the discharge operation, the liquid level control device 40 is operated by the dispensing operation control unit 302 so as to return the drawn-in fluid via the liquid level operation unit 401, whereby the liquid of the sample inside the probe 11 is returned. The surface position returns to the state before being operated by the liquid level control device 40.

  Furthermore, an acceleration sensor 41 can be added to the tip of the arm of the dispensing device 10 so that the acceleration acting near the probe can be measured. The acceleration sensor 41 may be removed once the relationship between the motor command acceleration and the acceleration acting near the probe is confirmed. As for the pressure value in the pipe from the pressure sensor 31, information on the timing at which the pressure measurement unit 402 generates a pressure change, the frequency of the pressure change and the phase of the frequency is recorded in the pipe pressure data 403.

As described above, the sample jumps out of the probe 11 due to the inertial force acting on the fluid inside the probe 11, and the acceleration acting on the fluid is measured by the acceleration sensor 41 or the like, thereby determining the lifting amount of the liquid surface position. be able to. For example, assuming that the acceleration value in the same direction as the probe 11 measured by the acceleration sensor 41 is a [m / s ² ], the volume of the fluid in the probe 11 is V [m ³ ], and the cross-sectional area of the pipe 50 is Let S [m ² ]. Here, the fluid in the probe 11 is defined as having a uniform density ρ. The inertial force acting on the fluid in the probe 11 can be expressed by ρVa, and the pressure change ΔP can be obtained by dividing this inertial force by the cross-sectional area of the pipe, and can be expressed by ΔP = ρVa / S. Here, by giving the pressure change value measured by the pressure sensor 31 and the acceleration acting on the probe 11 to the equation of ΔP = ρVa / S, the volume change amount can be obtained. The volume change thus obtained is the amount of liquid that jumps out of the probe 11, so that by drawing the same amount of fluid in the pipe, the liquid level at the tip of the probe is raised to a height at which the liquid does not jump out. Jumping out can be prevented. In addition to the method of calculating the amount of liquid to be ejected as described above, the actual amount of ejection may be confirmed in advance with a camera or the like.

  The liquid level control device 40 performs control for suppressing vibration of the liquid level of the sample in the probe by using the pressure data 403 in the pipe in which information on the timing at which the pressure change occurs, the frequency and the phase of the frequency are recorded. It is also possible to do this. Details will be described later.

  FIG. 5 is a diagram showing a probe speed waveform when the probe is moved up, a vertical direction measurement value of the acceleration sensor, and a pressure change in the pipe. FIG. 5A shows a change in speed when a trapezoidal waveform drive pattern is given to the motor that moves the arm up and down to raise the arm. FIG. 5B shows a waveform when the acceleration in the vertical direction generated in the vicinity of the probe when the driving shown in FIG. 5A is performed is measured by the acceleration sensor. FIG. 5C shows a waveform when the pressure change in the pipe when the driving of FIG. 5A is performed is measured with a pressure sensor. As shown in FIG. 5B, the probe vibrates by acceleration / deceleration of the arm raising operation, and the vibration remains even after the raising operation is completed. As shown in FIG. 5C, the pressure in the pipe also vibrates at the acceleration / deceleration timing of the arm raising operation. This is because the pressure in the pipe changes due to the fluid jumping out due to the inertial force acting on the fluid in the probe as described above.

  FIG. 6 is a diagram showing the flow of the dispensing operation. The dispensing apparatus 10 first rotates the arm 601 to the suction position, and performs air suction 602 using the probe 11 using the syringe pump 32. In order to insert the probe 11 into the test tube in which the serum is stored, the dispensing apparatus 10 lowers the arm 603 to the suction position and causes the syringe pump 32 to perform the suction operation 604 of the serum. After the suction, the dispensing apparatus 10 raises the arm 605 to the rotation position to rotate the arm, and performs the rotation operation 607 to the discharge position. At this time, before the arm moves up and stops, the liquid level control device 40 performs an operation for controlling the liquid level of the fluid and a liquid level operation 606. The liquid level operation 606 may be returned to the original state before the discharge operation is performed, but in FIG. 6, the liquid level operation 606 is returned to the original state during the rotation operation 607 to the discharge position. The dispensing apparatus 10 lowers the probe 11 to the discharge position of the reaction disk 22 in order to discharge the sucked serum 608. The dispensing apparatus 10 performs a serum discharge operation 609 by the syringe pump 32 at the discharge position. After dispensing, the dispensing device 10 raises the arm 610 to the rotational position, and performs the probe cleaning process 611 at the cleaning position.

  In the above-described dispensing operation, liquid scattering occurs between the suction operation 604 and the discharge operation 609, which affects the inspection accuracy. Therefore, after the suction operation 604, the fluid in the pipe is drawn by the liquid level control device 40, and the fluid drawn before the discharge operation 609 is returned to the original to prevent splashing due to the liquid jumping out due to the movement of the probe, The dispensing accuracy can be improved. In particular, in FIG. 5 (C), since the pressure in the pipe greatly changes with the stop time of the probe speed, the liquid is likely to be scattered at this timing. Therefore, in FIG. The liquid level operation 606 is performed before the stop.

  In other words, the dispensing apparatus control unit 300 raises the liquid level of the fluid filled in the pipe after the sample is sucked by the probe, and then lowers the liquid level of the raised fluid before discharging the sample. In this way, the liquid level control device 40 is controlled. In addition, as a minimum operation, at least the dispensing device control unit 300 controls the liquid level control device to raise the fluid level before the arm ascending operation stops. Note that, unlike the technique of Patent Document 1, the negative pressure of the piping system is not increased between the sample suction operation and the discharge operation by the syringe pump.

  Thus, separately from the syringe pump, by newly providing a liquid level control device and performing the above-described control, the syringe pump increases the negative pressure, thereby solving the problem that the dispensing accuracy deteriorates. High-speed operation and dispensing accuracy can be improved.

  FIG. 7 shows an example of the liquid level control device 40 when the piezoelectric actuator according to the present invention is used. In the example of the liquid level control device 40 in FIG. 7, an actuator that generates a small displacement by the piezo element 702 in the piezo actuator 701 is used, and a diaphragm 703 is used to transmit the displacement of the piezo element 702 to the fluid in the pipe. It is the structure which can control the fluid in piping. As described above, in order to raise the liquid level position of the sample of the probe, the piezo actuator 701 is driven to raise the diaphragm 703. At this time, the piezo actuator 701 needs to generate a displacement enough to manipulate the pop-out amount obtained as described above. If the target volume cannot be manipulated only by the displacement of the piezo element 702, a displacement enlargement mechanism or the like can be provided. In order to return the raised liquid surface position, the piezo actuator 701 may be driven so that the diaphragm 703 is returned to the original position.

  By performing the operation as described above from the suction operation to the discharge operation in which the sample jumps out of the probe, scattering of the sample can be suppressed. In FIG. 7, the piezo actuator 701 is used. However, any actuator such as a voice coil motor capable of positioning a minute displacement may be used.

  By using the piezo actuator 701, the diaphragm 703 is moved up and down in accordance with the frequency of the pressure change in the pipe recorded in the pipe pressure data 403 in advance, and the pressure is lowered when the pressure in the pipe rises. The amount of change in pressure can be reduced by performing an operation that generates a reverse-phase pressure, such as increasing the pressure at the timing when the pressure decreases. By using the above method, the liquid level vibration of the sample inside the probe can be suppressed, so that the sample discharge process can be performed with high accuracy. In other words, the liquid level control device controls the liquid level control device in the opposite phase to the frequency and the phase information so as to cancel out the pressure change based on the frequency and phase information of the pressure change of the pipe, thereby scattering the sample. Can be suppressed.

  FIG. 8 is an example of the liquid level control device 40 when the electromagnetic actuator according to the present invention is used. In the example of the liquid level control device 40 in FIG. 8, when the diaphragm 801 is connected to the fluid in the pipe and the coil 802 is not energized, the plunger 804 is pulled up by the spring 803. Acts to draw fluid inside. When the coil 802 is energized, the plunger 804 is pushed down, and the diaphragm 801 is driven to push back the fluid drawn into the pipe. Similar to the liquid level control device 40 described above, from the suction operation to the discharge operation where the sample jumps out of the probe, the coil 802 is de-energized to draw the fluid, thereby adjusting the liquid level position of the sample in the probe. By raising and energizing the coil 802 before discharging, the liquid surface position of the sample can be restored.

  In an example using an electromagnetic actuator or electromagnetic blanker, binary control of ON and OFF is performed. Therefore, in order to set the liquid level of the sample in the probe to a desired position, a mechanism such as a plunger 804 or a diaphragm 801 is designed in advance. There is a need to.

  As shown in FIG. 7 and FIG. 8, in the method of controlling the liquid level, the liquid vibration generated when the liquid level is controlled becomes smaller when the liquid volume to be controlled is smaller. It is desirable to be able to manipulate an amount equivalent to the amount. In addition, since a sudden liquid drawing operation generates a sudden change in pressure and vibrates, when operating the liquid level using an actuator as shown in FIG. 7, a trapezoidal waveform or S-shaped waveform is used for the driving speed. It is desirable to perform an operation that suppresses the vibration of the fluid using the.

  FIG. 9 is a diagram illustrating an example of a pressure accumulator that suppresses a pressure change in the present invention. FIG. 9 shows an accumulator comprising a gas container 901 and a container 902. The gas container 901 absorbs the pressure change in the pipe and suppresses the vibration of the fluid. Instead of the liquid level control device 40, by adding a pressure accumulator that absorbs the pressure change by changing the volume of the gas inside when the pressure change of the fluid in the pipe occurs, such as an accumulator, When an inertial force acts on the fluid in the probe, the gas container 901 functions in the same manner as a shock absorber, and the sample in the probe can be prevented from jumping out.

  By adding a mechanism that works as shown in any of FIGS. 7 to 9 to the pipe between the dispensing device 10 and the syringe pump 32, it is possible to prevent the sample from jumping out of the probe.

10 Dispensing device 11 Probe 21 Sample disc 22 Reaction disc 31 Pressure sensor 32 Syringe pump 33 Electromagnetic valve 34 Gear pump 35 Tank 40 Liquid level control device 41 Acceleration sensor 300 Dispensing device control unit 301 Dispensing sequence processing unit 302 Dispensing operation control Unit 303 Motor control unit 304 Syringe control unit 305 Pressure detection input unit 306 Dispensing sequence data 307 Dispensing operation parameter 310 Host communication processing unit 320 Host computer 330 Motor drive unit 401 Liquid level operation unit 402 Pressure measurement unit 403 In-pipe pressure data 601 Rotation to suction position 602 Air suction 603 Decrease to suction position 604 Suction operation 605, 610 Raise to rotation position 606 Liquid level operation 607 Rotation to discharge position 608 Decrease to discharge position 609 Discharge operation 611 Probe cleaning process 701 Piezo Actuator 702 piezoelectric elements 703,801 diaphragm 802 coil 803 spring 804 plunger 901 gas container 902 container

Claims (7)

A probe for aspirating and discharging a sample;
Piping connected to the probe;
A pump connected to the pipe for changing the pressure in the pipe;
A liquid level control device that is disposed in the pipe and controls the liquid level of the fluid filled in the pipe;
A dispensing device comprising: The dispensing device according to claim 1,
Furthermore, a control unit for controlling the liquid level control device,
The control unit raises the liquid level of the fluid filled in the pipe after the sample is sucked by the probe, and then discharges the sample to lower the liquid level raised before. Dispensing device for controlling position control device. The dispensing device according to claim 2,
Furthermore, an arm that moves up and down is provided with the probe at the tip,
The said control apparatus controls the said liquid level control apparatus to raise the liquid level of the said fluid, before the raise operation | movement of the said arm stops, The dispensing apparatus characterized by the above-mentioned. The dispensing device according to claim 1,
The liquid level control device includes a piezo actuator and a diaphragm driven by the piezo actuator. The dispensing device according to claim 1,
The liquid level control device includes an electromagnetic blanker and a diaphragm driven by the electromagnetic blanker. The dispensing device according to claim 1,
The control device controls the liquid level control device at a phase opposite to the frequency and the phase information so as to cancel the pressure change based on the frequency and phase information of the pressure change of the pipe. Note device. A probe for aspirating and discharging a sample;
Piping connected to the probe;
A pump connected to the pipe for changing the pressure in the pipe;
A pressure accumulator arranged in the pipe and in which the volume of gas inside changes when a pressure change of the fluid filled in the pipe occurs;
A dispensing device comprising: