JP5035941B2 - Dispensing device, dispensing method and analyzer - Google Patents

Description

  The present invention relates to a dispensing device, a dispensing method, and an analyzer for dispensing a liquid by sucking and discharging the liquid with a syringe having a piston.

  2. Description of the Related Art Conventionally, a dispensing device that drives a piston to suck a liquid into a syringe and discharges the liquid from the syringe, and an analyzer equipped with this dispensing device are known. In general, this piston is connected to a rotary motor via a rotation-linear motion conversion mechanism, and the rotary motion of this rotary motor is converted into a linear motion, and a liquid suction / discharge operation is performed. The dispensing device controls the liquid dispensing operation by controlling the rotation of the rotary motor.

  When performing minute dispensing with a minute dispensing amount, the driving profile that associates the driving time and driving distance of this piston differs depending on the characteristics of the liquid to be dispensed and the operating characteristics of the dispensing device. A technique for controlling dispensing by storing a driving profile of a piston for each characteristic of liquid to be poured is disclosed (see Patent Document 1).

JP 2000-65843 A

  By the way, when performing a minute amount dispensing, this piston needs to drive a predetermined distance within a predetermined time. FIGS. 7A to 7C are schematic diagrams illustrating a driving profile displayed by the driving distance (L) with respect to the piston driving time (t). The broken line is an ideal drive profile. When the drive start time is 0 and the drive stop time is Ts, the drive distance Lth is driven at time 0 to Ts.

However, as described above, since the piston is driven by a rotary motor, a rotation-linear motion conversion mechanism, etc., overshoot and undershoot exist for a predetermined drive distance Lth. As shown in FIG. 7A, when the overshoot L1 is excessive with respect to the driving distance Lth, the dispensing liquid 15A discharged from the nozzle 13 to the container 16 has an overshoot L1 with respect to a predetermined dispensing amount. Excessive discharge is performed by the volume V _L1 corresponding to the above.

Further, as shown in FIG. 7B, when the undershoot L2 is excessive with respect to the driving distance Lth, the dispensed liquid 15B that does not leave the nozzle 13 remains, and thus the dispensed liquid 15C discharged to the container 16 Is dispensed by a volume V _L2 corresponding to the undershoot L2 with respect to a predetermined dispensing amount.

  Further, as shown in FIG. 7C, when there is no excessive overshoot or excessive undershoot with respect to the driving distance Lth, but there is an excessive delay time TE with respect to a predetermined time 0 to Tth, dispensing is performed. The liquid 15D does not detach from the tip of the nozzle 13 at all and is not dispensed into the container 16.

  The above-described piston overshoot amount and undershoot amount are greatly influenced by individual differences of the dispensing devices. This individual difference is caused by a variation in mechanical operation from the rotary motor to the piston. Further, even in the same dispensing device, the frictional resistance varies depending on the positional relationship between the piston and the syringe, and the above-described overshoot amount and undershoot amount also differ depending on the drive start position and drive stop position of the piston. That is, there is a problem in that dispersion of dispensing cannot be prevented when piston driving is performed without considering individual differences of dispensing devices and frictional resistance between the syringe and the piston.

  The present invention has been made in view of the above, and an object thereof is to provide a dispensing device, a dispensing method, and an analyzer having uniform dispensing accuracy.

  In order to achieve the above object, a dispensing apparatus according to claim 1 is a dispensing apparatus that dispenses the liquid by sucking and discharging the liquid with a syringe having a piston. Drive control means for controlling the drive of the piston on the basis of a drive profile corresponding to the drive start position and / or drive stop position corresponding to the target dispensing amount and corresponding to the difference is provided. And

  According to a second aspect of the present invention, in the above invention, the dispensing apparatus further comprises position detecting means for detecting the driving position of the piston, and time measuring means for measuring the driving time of the piston, and the drive control means. Is characterized in that feedback control of the driving of the piston is performed based on the driving position detected by the position detecting means and the driving time measured by the time measuring means.

  According to a third aspect of the present invention, in the above invention, the dispensing device further comprises storage means for storing the drive profile in advance.

  Further, in the dispensing device according to claim 4, in the above invention, the drive profile stored in advance in the storage means is the shipment device of the dispensing device, the installation of the device, the startup of the device, It is obtained at the time of maintenance of the apparatus.

  According to a fifth aspect of the present invention, in the above dispensing device, the storage means has the drive profile for each of the plurality of liquids.

  In the dispensing device according to claim 6, in the above invention, the drive profile for each liquid is a drive profile for each physical property value such as viscosity and surface tension of the liquid. .

  The dispensing apparatus according to claim 7 is characterized in that, in the above invention, the individual difference is a variation in characteristics of the dispensing apparatus related to dispensing accuracy.

  The dispensing apparatus according to claim 8 is characterized in that, in the above invention, the variation in characteristics of the dispensing apparatus is a variation in performance such as positioning accuracy and speed control accuracy of the piston.

A dispensing method according to claim 9 is the dispensing method according to the invention described above, wherein the liquid is dispensed by sucking and discharging the liquid with a syringe having a piston.
A drive control step for controlling the driving of the piston based on a driving profile corresponding to the individual driving amount of the dispensing apparatus and corresponding to the driving start position and / or the driving stop position of the piston according to the target dispensing amount. It is characterized by including.

  The dispensing method according to claim 10 further includes a position detecting step for detecting the driving position of the piston in the above invention, and a timing step for measuring the driving time of the piston, and the position detecting step. The method includes a step of performing feedback control of driving of the piston based on the detected driving position and the driving time measured by the timing step.

  An analyzer according to claim 11 is characterized in that, in the above-mentioned invention, the dispensing device according to any one of claims 1 to 8 is provided.

  The dispensing device, the dispensing method, and the analysis device according to the present invention have an effect that the dispensing accuracy can be made uniform by driving the piston based on the drive profile corresponding to the dispensing amount for each device.

  Exemplary embodiments of a dispensing device, a dispensing method, and an analyzer according to the present invention will be described below in detail with reference to the accompanying drawings.

(Embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a dispensing apparatus 1 according to the present invention. As shown in FIG. 1, the dispensing apparatus 1 includes a control unit 2 that controls dispensing, a storage unit 3 that stores a drive profile of the piston 10, an input unit 4 that inputs information related to dispensing, and a control. Position control which inputs the control signal S1 from the part 2 and detects the position of the piston 10 based on the motor driver 5 which drives and controls the motor 8, the motor 8 which is driven by the motor driver 5, and the rotational position of the motor 8 7, a signal converter 6 that converts the position detected by the position detector 7 into a detection signal S 2, a ball screw 9 that converts the rotational motion of the motor 8 into linear motion, and a piston 10 that is connected to the ball screw 9. , A syringe 11 that houses the piston 10, a reservoir 14 that houses the liquid 15, a three-way valve 12 that inputs a selection signal S <b> 3 from the control unit 2 to switch suction and discharge, and discharges the liquid 15 to the container 16. And a nozzle 13 that. The control unit 2 includes a timer 20 that measures the time for which the piston 10 is driven.

  When the control unit 2 inputs the viscosity and the dispensing amount related to the liquid 15 via the input unit 4, the control unit 2 extracts a table corresponding to the input viscosity and dispensing amount from the storage unit 3. Each table includes a driving start position, a driving distance, a driving stop position, and a driving pattern, which are driving profiles of the piston 10.

  The control unit 2 generates a control signal S1 based on the drive profile described in the extracted table, outputs the control signal S1 to the motor driver 5, and inputs the detection signal S2 from the signal converter 6, and is connected to the ball screw 9. The drive of the piston 10 is feedback controlled.

  Here, the dispensing operation of the dispensing apparatus 1 will be described. The control unit 2 outputs the selection signal S3 to the three-way valve 12, switches the suction port of the three-way valve 12 to the reservoir 14 side, outputs the control signal S1, and moves the piston 10 to the driving start position described in the table. The liquid 15 is sucked from the reservoir 14.

  Next, the control unit 2 outputs a selection signal S3 to the three-way valve 12, switches the suction port of the three-way valve 12 to the syringe 11 side, outputs a control signal S1, and based on the drive pattern described in the table The piston 10 is driven, and the piston 10 is stopped at the drive stop position. The liquid 15 is dispensed by driving the piston 10 from the drive start position to the drive stop position.

  Here, the drive profile stored in the storage unit 3 will be described. FIG. 2 is a schematic diagram showing specific contents of the drive profiles described in the tables T1 to Tn. As shown in FIG. 2, the tables T <b> 1 to Tn are divided for each liquid viscosity, and one table has a driving distance, a driving start position, a driving stop position, which is a driving profile of the piston 10 for each dispensing amount, A drive pattern is described.

  The driving distance indicates the distance that the piston 10 drives, the driving start position indicates the position with respect to the syringe 11 where the piston 10 starts driving, and the driving stop position indicates the position with respect to the syringe 11 where the piston 10 stops driving. The drive pattern indicates a speed change pattern from the start of driving of the piston 10 to the stop of driving.

  In the tables T1 to Tn, driving profiles having an inner diameter of the syringe 11 of φ0.2 mm are described. For example, a driving profile for dispensing the liquid 15 having a viscosity of 1.0 (mPa · s) is shown in the table T1. When dispensing 90 (nL), the drive start position of the piston 10: 5, the drive distance: 2.86 (mm), the drive stop position: 7.86, and the drive pattern: A are shown. This indicates that when the piston 10 is driven from the syringe 11 position: 5 to the syringe 11 position 7.86 by the drive pattern: A, 90 (nL) can be dispensed.

  In addition, when the liquid 15 is dispensed by 10 (nL), the driving start position of the piston 10: 1, the driving distance: 0.32 (mm), the driving stop position: 1.32, and the driving pattern: B are shown. . This indicates that 10 (nL) can be dispensed when driven from syringe 11 position: 1 to syringe 11 position: 1.32 by drive pattern: B.

  Thus, when the dispensing amount is different, not only the driving distance of the piston 10 but also the driving start position and the driving stop position are different. In addition, depending on the positional relationship of the syringe 11 with respect to the dispensing device 1, there is a case where the drive start position is prioritized and a case where the drive stop position is prioritized, both the drive start position and the drive stop position are described.

  Here, the drive pattern will be described. FIG. 3 is a schematic diagram showing drive patterns: A and B. As shown in FIG. 3, the drive pattern: A is for 90 (nL) dispensing, and the drive pattern: B is for 10 (nL) dispensing. Drive patterns A and B not only have different drive distances but also different accelerations, overshoots, and the like. This is because the drive pattern is varied according to the dispensing amount, and the liquid mass of the liquid 15 is completely separated from the tip of the nozzle 13.

  The dispensing apparatus 1 has many mechanical parts, and variations in characteristics of these mechanical parts cause variations in the linear motion of the piston 10. Furthermore, the frictional resistance between the syringe 11 and the piston 10 varies depending on the location. For this reason, there are variations in performance such as positioning accuracy and speed control accuracy of the piston 10. That is, by storing a drive profile in consideration of various variations caused by individual differences of the dispensing devices 1 and driving the piston 10 based on this drive profile, the dispensing accuracy can be kept uniform.

  Next, an analyzer equipped with this dispensing device will be described. FIG. 5 is an upper surface of the analyzer 30 provided with the dispensing devices 1a and 1b. As shown in FIG. 5, this analyzer 30 has a work table 31. The work table 31 is a reaction table that mixes a specimen table 32 that contains specimens, a reagent table 39 that contains reagents, and a reagent and specimen. 34, and also has dispensing devices 1a and 1b for dispensing reagents and specimens, respectively.

  In addition, the work table 31 includes a reading device 41 that individually identifies the reagent containers 40 stored in the reagent table 39, a light source 36 that irradiates analysis light to the reaction container 35 in which the reagent and the sample are mixed, and a reaction container. A light receiving element 37 for receiving the light transmitted through 35, and a cleaning device 38 for cleaning the reaction vessel 35 that has been analyzed.

  The dispensing apparatus 1a aspirates the sample from the sample container 33 accommodated in the accommodation chamber 32a of the sample table 32, and discharges the sample into the reaction container 35 accommodated in the accommodation chamber 34a of the reaction table 34, so that the dispensing apparatus 1b. Draws the reagent from the reagent container 40 accommodated in the accommodation chamber 39 a of the reagent table 39 and discharges the reagent into the reaction container 35.

  The two dispensing devices 1a and 1b individually perform pistons (not shown) based on the drive profiles corresponding to the dispensing amount, so that the desired dispensing can be performed reliably. Can be kept uniform, and the analysis accuracy can be kept uniform.

  In this embodiment, the driving profile of the piston 10 is stored in advance for each dispensing amount, and dispensing is performed based on the stored driving profile, so that the dispensing accuracy can be kept uniform. Further, a supply and discharge device for the reaction vessel 35 may be provided in place of the cleaning device 38 in FIG. Is done.

  In the embodiment, the storage unit 3 creates the tables T <b> 1 to Tn for each viscosity of the liquid 15, but may create a table for each other characteristic of the liquid 15. Other physical properties include, for example, the viscosity based on the surface tension of the liquid or the liquid temperature. Further, all the driving profiles may be described in one table.

  Further, the drive profile may be updated periodically in order to cope with the change over time of the individual difference of the dispensing device 1. In addition, the drive profile may be updated in a timely manner, such as at the time of shipment of the device in which mechanical fluctuation is predicted, at the time of installation, at the time of starting up the device, or at the time of maintenance of the device. In addition, a driving profile may be created by actually performing a dispensing operation using a liquid, or a driving profile may be created using a simulation calculation. Or you may produce combining the dispensing operation | movement using a liquid, and simulation calculation.

  FIG. 4 is a block diagram showing a schematic configuration of the analyzer 30 having the dispensing device 1. As shown in FIG. 4, the analysis device 30 includes a dispensing device 1 and an analysis unit 21 that analyzes the liquid dispensed by the dispensing device 1. Since the dispensing apparatus 1 can dispense the liquid to be analyzed with uniform accuracy, the analysis unit 21 can analyze the liquid with uniform accuracy.

(Modification 1)
Next, Modification Example 1 of this embodiment will be described. In the embodiment, the position detector 7 detects the rotational position of the motor 8 and indirectly detects the position of the piston 10. However, in the first modification, the position detector is arranged on the axis of the piston 10. In addition, the position of the piston 10 is directly detected.

  FIG. 5 is a block diagram showing a schematic configuration of a dispensing apparatus 1A according to Modification 1 of the embodiment. As shown in FIG. 5, in the dispensing apparatus 1A, the position detector 7 shown in the embodiment is replaced with a position detector 7A, and the signal detector 6 is replaced with a signal detector 6A. Other configurations are the same as those of the dispensing apparatus 1 shown in the embodiment, and the same components are denoted by the same reference numerals.

  The position detector 7A is disposed between the ball screw 9 and the piston 10, and directly detects the position of the piston 10, and outputs the position of the piston 10 to the control unit 2 as a detection signal S2. The control unit 2 creates a drive profile of the piston 10 based on the detection signal S2 and the time counted by the timer 20, and stores the drive profile in the storage unit 3. The control unit 2 performs feedback control of the piston 10 based on the detection signal S2 and the control signal S1 based on the drive profile stored in the storage unit 3.

  In the first modification, since the position detector 7A directly detects the position of the piston 10, it is possible to create a highly accurate drive profile without mechanical play or the like generated between the ball screw 9 and the motor 8, and to the piston 10. Highly accurate feedback control. The rotation-linear motion conversion mechanism of the embodiment and the modification shown in FIGS. 1 and 5 may employ a rack and pinion mechanism instead of the ball screw 9.

(Modification 2)
Next, a second modification of this embodiment will be described. In the embodiment and the first modification, the piston 10 is driven using the motor 8 and the ball screw 9, but in the second modification, the piston 10 is driven using a linear motor.

  FIG. 6 is a block diagram showing a schematic configuration of a dispensing device 1B according to Modification 2 of the embodiment. As shown in FIG. 6, in the dispensing apparatus 1B, the motor 8 shown in the modified example 1 is replaced with a linear motor 8A, and the motor driver 5 is replaced with a motor driver 5A. Other configurations are the same as those of the dispensing apparatus 1A shown in the first modification of the embodiment, and the same components are denoted by the same reference numerals.

  The control unit 2 controls the motor driver 5A with the control signal S1, and the motor driver 5A drives the linear motor 8A based on the control signal S1. The linear motor 8A and the piston 10 are directly connected, and the position detector 7A is disposed between the linear motor 8A and the piston 10, and directly detects the position of the piston 10.

  When the piston 10 is driven by the linear motor 8A, the conversion mechanism for converting the rotational motion into the linear motion can be omitted, the mechanical play caused by the conversion mechanism can be eliminated, high-accuracy driving and space saving can be achieved. I can plan.

It is a block diagram which shows schematic structure of the dispensing apparatus concerning embodiment of this invention. It is a schematic diagram which shows the specific content of the table concerning embodiment of this invention. It is a schematic diagram which shows the drive pattern concerning embodiment of this invention. It is a top view which shows schematic structure of the analyzer which has a dispensing apparatus concerning embodiment of this invention. It is a block diagram which shows schematic structure of the dispensing apparatus concerning the modification 1 of embodiment of this invention. It is a block diagram which shows schematic structure of the dispensing apparatus concerning the modification 2 of embodiment of this invention. It is a schematic diagram which shows the drive profile of the piston which is not appropriate. It is a schematic diagram which shows the drive profile of the piston which is not appropriate. It is a schematic diagram which shows the drive profile of the piston which is not appropriate.

Explanation of symbols

1, 1A, 1B Dispensing device 2 Control unit 3 Storage unit 4 Input unit 5, 5A Motor driver 6, 6A Signal converter 7, 7A Position detector 8 Motor 8A Linear motor 9 Ball screw 10 Piston 11 Syringe 12 Three-way valve 13 Nozzle DESCRIPTION OF SYMBOLS 14 Reservoir 15 Liquid 16 Container 20 Timer 21 Analysis part 30 Analyzer 31 Work table 32 Specimen table 32a, 34a, 39a Storage chamber 34 Reaction table 35 Reaction container 36 Light source 37 Light receiving element 38 Washing device 40 Reagent container 41 Reading device

Claims (9)

A dispensing device that dispenses the liquid by sucking and discharging the liquid with a syringe having a piston ,
The dispensing device is
The dispenser corresponds to the individual difference of the device, and the target dispensing amount to the drive control means for controlling the driving of the piston based on the driving profile corresponding to the drive start position and / or drive stop position of the piston in response When,
Position detecting means for detecting the driving position of the piston;
Timing means for timing the drive time of the piston;
With
The dispenser characterized in that the drive control means feedback-controls the drive of the piston based on the drive position detected by the position detection means and the drive time measured by the time measuring means . The dispensing apparatus according to claim 1 , further comprising storage means for storing the driving profile in advance. The drive profile stored in advance in the storage means is acquired at the time of shipment of the dispensing device, at the time of installation of the dispensing device, at the start-up of the dispensing device, and at the time of maintenance of the dispensing device. The dispensing device according to claim 2 . Said storage means, dispensing apparatus according to any one of claims 1-3, characterized in that having the drive profile for each of a plurality of said liquid. 5. The dispensing apparatus according to claim 4 , wherein the driving profile for each liquid is a driving profile for each physical property value such as viscosity and surface tension of the liquid. The individual differences, dispensing dispensing apparatus according to any one of claims 1-5, characterized in that the variations in the characteristics of the dispensing device according to the accuracy. The dispensing device according to claim 6 , wherein the variation in characteristics of the dispensing device is a variation in performance such as positioning accuracy and speed control accuracy of the piston. A dispensing method for dispensing the liquid by sucking and discharging the liquid with a syringe having a piston ,
The dispensing method is:
Drive control step of controlling the driving of the piston based on the driving profile corresponding to the drive start position and / or drive stop position of the piston corresponding to the individual difference of the dispensing device, and corresponding to the target dispensing amount When,
A position detecting step for detecting a driving position of the piston;
A time measuring step for measuring the driving time of the piston;
Including
A dispensing method comprising a step of performing feedback control of driving of the piston based on the driving position detected by the position detecting step and the driving time measured by the timing step . An analyzer comprising the dispensing device according to any one of claims 1 to 7 .

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