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EP-4190449-B1 - DISPENSING DEVICE

EP4190449B1EP 4190449 B1EP4190449 B1EP 4190449B1EP-4190449-B1

Inventors

  • HARA DAISUKE
  • YAMAGATA TOSHIKI
  • SHIBAHARA MASASHI

Dates

Publication Date
20260506
Application Date
20200803

Claims (4)

  1. A dispensing device (100) configured for suctioning a liquid sample with a dispensing tip (110) and for discharging a predetermined amount of the suctioned liquid sample to perform dispensing, the dispensing device (100) comprising: a pressure sensor (113) configured to measure an internal pressure of the dispensing device (100); a pipette mechanism (108, 109) comprising a piston (108) and a receiving piston (109) configured to perform suction and discharge; an automatic drive stage to drive the dispensing device (100) in a vertical direction; a drive unit (102) configured to drive the piston (108) of the pipette mechanism (108, 109), wherein the dispensing tip (110) is mounted on the pipette mechanism (108, 109), and the drive unit (102) is configured to drive the pipette mechanism (108, 109) in a suction or discharge direction; and a control unit (116) configured to control the drive unit (102) based on an output of the pressure sensor (113), wherein the control unit (116) is configured to determine a type of the dispensing tip (110) based on a pressure waveform measured by the pressure sensor (113) while the pipette mechanism (108, 109) is performing suction or discharge, characterised in that the control unit (116) is configured to determine the type of the dispensing tip (110) by: driving the dispensing device (100) with the automatic stage in the vertically downward direction while the piston (108) is driven in the suction direction or in the discharge direction and while measuring the pressure with the pressure sensor (113); detecting that the dispensing tip (110) reaches a liquid level using the pressure measurements; obtaining a slope of an approximate straight line of a pressure waveform obtained during a time while the drive unit (102) is performing suction or discharge from the time of liquid level detection; and comparing the slope of the approximate straight line with a value measured in advance, in order to determine the type of the dispensing tip (110).
  2. The dispensing device (100) according to claim 1, wherein the control unit (116) is configured to output an error notification when it is determined that an inappropriate dispensing tip (110) is mounted as a result of determining the type of the dispensing tip (110).
  3. The dispensing device (100) according to claim 1, wherein the control unit (116) is configured to store a liquid level position when it is determined that an appropriate dispensing tip (110) is mounted as a result of determining the type of the dispensing tip (110).
  4. The dispensing device (100) according to claim 1, wherein the dispensing tip (110) has a filter, and the control unit (116) is configured to determine the type of the dispensing tip (110) based on the pressure waveform obtained when a liquid is suctioned beyond a specification volume of the dispensing tip (110) with a filter.

Description

Technical Field The present invention relates to a dispensing device, and particularly to a technique for determining a type of a tip of a dispensing mechanism for examination. Background Art A dispensing device is used as a method for distributing a liquid such as a specimen and a reagent to another container in medical and biomedical fields. In an examination using a polymerase chain reaction (hereinafter, referred to as PCR) method in such as a gene examination device, since even slight contamination affects an examination result, it is important to prevent contamination in order to obtain a correct examination result. As an example, PTL 1 discloses an invention for monitoring a pressure in the dispensing device and effectively reducing the occurrence of liquid dripping from a nozzle and an air gap. If the liquid dripping occurs, the dropped liquid droplets may contaminate other containers, and if an air gap occurs, liquid pools may occur at a tip of the nozzle via the air gap. When the liquid is discharged, contamination may occur due to the generation of bubbles or flipping of the bubbles. In order to cope with these problems, in PTL 1, air suction setting information is information in which air suction conditions defined in advance for each of various dispensing conditions (a shape of the nozzle, a type of the liquid, a target suction amount, and the like), more specifically, an air suction speed va, an air amount upper limit value Va, and the like are recorded, and the air suction setting information is defined based on previous experimental results and the like. In addition, PTL 1 discloses that the liquid dripping can be more reliably prevented or reduced by performing the air suction based on the air suction conditions defined in advance. In the related art, it is intended to prevent contamination by reducing liquid dripping or an air gap generated after the suction of a liquid. Citation List Patent Literature PTL 1: JP 2010 256200 A JP 2006 194689 A discloses a dispensing device with the features in the preamble of present claim 1. Further conventional dispensing devices are described in EP 3 671 221 A1, US 2009/288470 A1, US 4 846 003 A, and US 2009/211380 A1. Summary of Invention Technical Problem In the related art, there is a device configuration in which the nozzle is washed each time and used repeatedly, but in the examination using the PCR method in such as a gene examination device, even the slight contamination affects the examination result. Therefore, it is common to use a disposable tip for the nozzle. Since the required dispensing amount is different for each examination item, a plurality of types of tips suitable for the dispensing amounts are used. In particular, in a dispensing device having a wide dispensing range, since a large volume dispensing tip or a small volume dispensing tip may be used, there are a wide variety of types of tips. In a case where the plurality of types of tips are used, when suction is performed beyond a tip volume, the inside of the dispensing device may be contaminated. Therefore, it is necessary to determine whether the dispensing amount and the mounted tip match with each other. For example, a human error such as an installation error in a type of a tip can be considered as a factor. By making a case dedicated such that only a specific tip can be housed, the relation between the tip and a tip case can be uniquely determined, but it cannot be determined whether a tip suitable for the dispensing amount is installed. Although an installation error can be prevented, it is still necessary to determine whether a tip suitable for the dispensing amount is installed. From the viewpoint of dispensing accuracy, it is important to determine a type of a tip. The larger a tip volume, the larger an air volume inside the tip. Therefore, when the air volume is excessively large relative to the dispensing amount, there is a possibility that no dispensing accuracy can be satisfied. An object of the invention is to provide a dispensing device capable of solving the above problems and preventing contamination in the dispensing device caused by a mismatch between a tip and a dispensing amount at the time of dispensing. Solution to Problem In order to achieve the above object, the invention provides a dispensing device as defined in claim 1. Advantageous Effects of Invention According to the invention, it is possible to determine a type of a tip, that is being used, based on characteristics of the pressure waveform. Brief Description of Drawings [FIG. 1] FIG. 1 is a diagram showing an example of a configuration of a dispensing device and a liquid level detection operation according to the present disclosure.[FIG. 2] FIG. 2 is a diagram showing a pressure waveform obtained when a piston is operated in a discharge direction to detect a liquid level according to the present disclosure.[FIG. 3] FIG. 3 is a diagram showing a pressure waveform obtained when the piston is operated