JP2013044530A - Dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need of complicated setting due to dependency on specifications of a nozzle or the like when detection is performed on the basis of a pressure, in a technology of detecting an abnormality such as suction of bubbles and air and clogging on the basis of data of a pressure sensor even for liquids of different viscosities in a dispenser.SOLUTION: The dispenser includes: a nozzle; pressure generation means for changing a pressure inside the nozzle; a pressure sensor for detecting the pressure inside the nozzle; a storage part for storing a conversion equation for obtaining viscosities corresponding to a plurality of points of time from pressure values at the plurality of points of time of a pressure waveform obtained by the pressure sensor when a standard liquid of a known viscosity is sucked or discharged; and a control part for calculating, by using the conversion equation, the viscosities at the respective points of time from the pressure values at the plurality of points of time of the pressure waveform obtained by the pressure sensor when a fluid of an unknown viscosity is sucked or discharged.

Description

  The present invention relates to a dispensing device for dispensing a fluid. Moreover, it is related with the measuring device which measures the physical property of fluid.

  In an automated analyzer that qualitatively and quantitatively analyzes biological samples such as blood and urine, a predetermined amount of sample is sucked with a nozzle and discharged to a reaction container by a predetermined amount, and then the reagent is sucked with another nozzle and the sample enters. And a dispensing system for discharging a predetermined amount of reagent to the reaction container. The dispensed sample and the reagent react in the container, and the color of the sample produced by the reaction is measured using an optical measuring means or the like. During the above suction operation, bubbles or air may be sucked into the nozzle for some reason or foreign matter may be clogged, and bubbles or air may be mixed during discharge, or it will be difficult to discharge the liquid, and a predetermined amount of liquid will be distributed to the container. May not be able to note. In such a case, a correct analysis result may not be obtained. In order to solve such a problem, a technique is known in which a pressure sensor is provided in a dispensing system to measure suction pressure and detect suction or clogging of bubbles or air (Patent Document 1).

  In addition, in a dispensing device, a technique for performing data verification by storing a pressure signal from a pressure sensor and enabling monitoring at a later date is known (Patent Document 2).

  In addition, a technique for calculating a viscosity value of a specimen for the purpose of correcting absorbance in an automatic analyzer is disclosed (Patent Document 3).

JP 2006-300814 A JP 2009-121838 A JP 2010-111282 A

  In the technique of Patent Document 1, a mathematical formula such as an exponential function is fitted to the suction pressure curve, and the actually measured curve is compared with the curve obtained from the mathematical formula. The pressure change varies depending on the dispensing conditions and the specifications of the dispensing system, and the same error does not always occur with respect to the curve represented by the mathematical formula, but there is a problem that the application range is limited.

  In addition, the technique of Patent Document 2 is a data verification technique using a pressure value, similar to the technique of Patent Document 1, and also depends on the dispensing conditions and the specifications of the dispensing system, so that the scope of application is limited. There are challenges.

  In the technique of Patent Document 3, the viscosity value is calculated from the pressure. Since the viscosity is calculated for the purpose of correcting the absorbance, the suction of bubbles or air or the clogging of foreign matter is determined from the calculated viscosity. I can't. For example, there is a problem that it is not possible to distinguish between a case where a fluid having a low viscosity is sucked and a case where a fluid having a high viscosity is sucked but a bubble is sucked and thus the viscosity is calculated to be low.

  Representative means for solving the above problems are as follows.

  The present invention relates to a nozzle for sucking or discharging a fluid, a pressure generating means for changing the pressure in the nozzle, a pressure sensor for detecting the pressure in the nozzle, and at the time of sucking or discharging a standard liquid having a known viscosity. Obtained from a pressure sensor at the time of suction or discharge of a fluid of unknown viscosity, from a pressure value obtained at a plurality of time points of a pressure waveform obtained by the pressure sensor, a storage unit for storing a conversion formula for obtaining a viscosity corresponding to the plurality of time points And a controller that calculates a viscosity at each time point from the pressure values at the plurality of time points of the pressure waveform using a conversion formula.

  According to the present invention, since the control unit for calculating the physical property of the fluid called the viscosity of the fluid is provided, not only the advantage of not depending on the specification of the dispensing system but also the time-lapse for calculating the viscosity at each time point in a plurality of time points. By observing various changes, there is an advantage that abnormalities in the dispensing system can be grasped. Unlike normal pressure waveforms that vary with time even in normal suction or discharge operations, it is calculated as a constant viscosity, so there is no need to set complex threshold values along the waveform, and air or bubble suction or foreign matter Detection of abnormal phenomena such as clogging can be simplified. As a result, the detection of the foreign matter phenomenon can be speeded up.

It is a block diagram of an automatic analyzer. It is a figure which shows the dispensing flow path system of a dispensing apparatus. It is a figure which shows the pressure waveform measured with the pressure sensor of the dispensing apparatus. It is a figure which shows the relationship between a pressure sensor output value and a viscosity. It is the figure which calculated | required the viscosity waveform converted from the pressure waveform using the viscosity conversion formula group. It is a flowchart of operation | movement of a dispensing apparatus. It is a figure which shows having plotted two-dimensionally the viscosity conversion waveform average value and standard deviation when many are dispensed with an automatic analyzer.

  Hereinafter, modes for carrying out the invention will be described.

  FIG. 1 shows a configuration of an automatic analyzer 10 that measures blood components as an embodiment. The automatic analyzer 10 includes a sample disk 11 storing a sample container (mainly holding serum), a reagent disk 12 storing a reagent container, a reaction disk 13 storing a reaction cell for mixing and reacting both, a sample and a reagent. Dispensing mechanisms 14 and 15 for pouring, a detector 16 for detecting the absorbance of the reaction solution in the reaction cell, a control unit 17 for controlling these operations, a console 18 serving as a man-machine interface, and a washing mechanism 19 for washing the reaction cell And a stirring mechanism 101 that stirs the sample and the reagent. The control unit 17 or the console 18 includes a storage unit that stores information.

  Next, an outline of the operation of the apparatus will be described. First, a sample is dispensed into the reaction cell from the sample container 27 on the sample disk 11 by the sample dispensing mechanism 14. The dispensing device of the present invention includes at least the dispensing mechanism and the control unit 17, and the flow path system 20 of the dispensing mechanism changes the nozzle 21 and the syringe pump 22 (the pressure in the nozzle changes as shown in FIG. 2). Pressure generating means) and a tube 23 that connects the pressure generating means), and sucks and discharges liquid from the tip of the nozzle 21 using the volume change caused by the movement of the plunger 24 in the syringe pump 22 (the valve 25 is opened and closed as appropriate). The liquid is injected from the water tank into the fluid system to clean the inside of the nozzle 21). Next, the reaction disk 13 storing the above reaction cell rotates and stops when it reaches the reagent dispensing position. Thereafter, the reagent is dispensed from the reagent container mounted on the reagent disk 12 into the reaction cell by the reagent dispensing mechanism 15. Further, the reaction cell rotates and moves to the position of the stirring mechanism 101, and the sample and the reagent in the reaction cell are stirred and mixed. The measurement by the detector 16 is started from the time when the stirring is completed, and when the reaction is completed, the mixture of the sample and the reagent in the reaction cell is sucked by the cleaning mechanism 19 and the cleaning process is performed. A series of processes are repeated to analyze a large number of samples.

  The dispensing operation starts from inserting the tip of the nozzle 21 into the container 27. At this time, the electrostatic capacity between the nozzle 21 and the liquid in the container 27 is measured, and the liquid level is detected by a change in the electrostatic capacity that occurs when the nozzle 21 comes into contact with the liquid. Thereafter, the nozzle 21 is further lowered so that the tip of the nozzle 21 enters the liquid so as not to suck air. However, there is a case where the liquid film or floating bubbles generated on the liquid surface cannot be distinguished from the liquid surface by the electrostatic capacity, and the liquid film or the bubble 28 at a position higher than the liquid surface is erroneously detected as the liquid surface. 21 may not reach the original liquid level and may inhale air or bubbles. If these are discharged into the reaction vessel, they may deviate from the originally set liquid volume, which may cause an inaccurate analysis result.

  A pressure sensor 26 is provided in the middle of the flow path in the flow path system 20 of the dispensing mechanism to detect a change in pressure in the nozzle. In the present embodiment, the liquid such as the nozzle 21 and the tube 23 is filled with the liquid. When a flow is generated in the liquid in the flow path, a pressure difference is generated in the flow direction of the flow path. In the case of a circular tube, this pressure difference is proportional to the viscosity and flow rate of the liquid flowing in the flow path and the length of the flow path, and inversely proportional to the fourth power of the flow path inner diameter (Hagen-Poiseuille's law). The pressure at the tip of the flow path system (the tip of the nozzle 21) matches the atmospheric pressure, and the output of the pressure sensor 26 provided in the middle of the flow path varies depending on the speed and viscosity of the fluid in the flow path with reference to the atmospheric pressure. . When air is sucked instead of liquid, the change in output is small because the viscosity of air is negligibly small compared to liquids such as water. In addition, when a large number of bubbles or the like enter, a large number of liquid-air interfaces are generated in the flow path, resulting in resistance due to the interfacial force, resulting in a large pressure difference and fluctuation. Further, when solid matter such as particles is sucked into the suction pipe, the flow is blocked and the pressure difference increases. Dispensing abnormality is detected by capturing the change in pressure deviating from normal as described above. However, this embodiment is not a pressure waveform itself, but a dispensing device that converts a pressure waveform into a viscosity waveform and detects an abnormality using the viscosity and its change.

  First, as a preparation, several types of standard viscosity liquids that cover the viscosity range dispensed by the automatic analyzer 10 are prepared as standard liquids. The viscosities of these standard solutions are known. This standard solution is normally sucked at the same flow rate as when the automatic analyzer 10 is operated (a standard state in which bubbles and air are not sucked or clogged), and at the same time, a pressure waveform (output of the pressure sensor 26) is stored in the storage unit. Record. Also, air is sucked and the pressure waveform is recorded at the same time. An example of a pressure waveform obtained as a result of these operations is shown in FIG.

  Hereinafter, FIG. 3 will be described. This waveform is obtained by AD conversion of the electrical signal from the pressure sensor 26 and represents the pressure. The pressure waveform data acquired in this way is called standard data. The waveform is air, and five glycerin aqueous solutions of different concentrations with known concentrations (abbreviated as GL in the figure, the concentration is 0 to 60%, the range of normal dispensing is the concentration 0 to 40%, and more than 50% This is the case where an aqueous solution is sucked). Each waveform rises with the start of suction, and when suction is finished (time 380 ms), the output of the pressure sensor decreases. Since the viscosity of air is the smallest and the concentration of the glycerin aqueous solution increases and the viscosity also rises, the pressure waveform due to suction is the smallest in the case of air and increases corresponding to the size of the glycerin concentration. Small fluctuations due to causes such as fluid elasticity and mechanical vibration are superimposed on a part of the waveform. Further, since the nozzle is generally thin at the tip, thick at the base, and the size varies depending on the application, the pressure change accompanying the suction of the liquid varies depending on the type of the nozzle. Therefore, it is desirable to measure these pressure waveforms every time the nozzle changes, and to measure the pressure waveforms using a nozzle that actually sucks or discharges a sample. The measured information is stored in the storage unit of the dispensing device.

  Since the waveform obtained from the pressure sensor 26 is AD-converted and taken into the apparatus at a constant time interval, the set of the value pi at a certain time ti (i-th AD conversion) of each waveform and the viscosity v of the fluid that generated each waveform From FIG. 4, a graph as shown in FIG. 4 is obtained. FIG. 4 illustrates the relationship between the viscosity and the output value of the pressure sensor by picking up 100, 120, 200, and 300 ms (corresponding to the 100th to 300th samples since sampling is performed at a cycle of 1 ms) in the waveform of FIG. From these data, a pressure-to-viscosity conversion formula (hereinafter referred to as a viscosity conversion formula) of v = fi (p) at each time point ti is created and stored in the storage unit. Viscosity conversion formulas are created for each pressure data acquired as a pressure waveform at regular time intervals, or a plurality of viscosity conversion formulas are selected from the pressure data and used as a pressure conversion formula group. The viscosity conversion formula can be described by an equation representing a straight line or a curve by an existing interpolation method such as a least square curve or a spline curve. In FIG. 4, a set of straight lines connecting the points is a viscosity conversion formula.

  FIG. 5 shows a converted viscosity waveform obtained from the pressure waveform of the standard data in FIG. 3 using a viscosity conversion formula group. As can be seen from the figure, when the converted viscosity value is 20 ms or less and 420 ms or more, the difference between the pressure waveforms becomes small, so that the calculation error increases and the viscosity value may fluctuate. There is little variation between 20 and 420 ms, and the value is almost constant. The pressure waveform in FIG. 3 varies depending on the elasticity of the fluid system, the vibration of the mechanism system, the nozzle shape, and the like. However, since the approximate expression is used in the viscosity conversion expression, it can be converted into viscosity using this conversion expression. These fluctuations will not be seen. Thereby, the viscosity which is a physical property of the fluid can be calculated. In this way, by displaying the time variation of the viscosity calculated by the control unit on the console 18 (display unit), the operator can confirm the time variation and can easily determine whether or not there is an abnormality. This is because, in a predetermined time zone, it is sufficient to confirm whether the viscosity that should be a constant value is a constant value without depending on the time variation.

  The pressure conversion formula group obtained from the above is stored in a storage unit (not shown) provided in the control unit 17 of the automatic analyzer 10, and at each time point of the pressure waveform measured when the automatic analyzer 10 dispenses a sample or a reagent. Is input into a viscosity conversion formula corresponding to the time point and converted into a converted viscosity waveform. Usually, since the suction is completed within a few seconds, the temperature change can be ignored. Therefore, if there is no abnormality such as air, bubbles, or clogging, the converted viscosity waveform during the suction hardly changes and becomes a constant value. However, when air, bubbles, clogging, etc. occur, the pressure waveform changes, and this appears as a change in the converted viscosity. By utilizing this fact, a parameter representing the fluctuation, for example, standard deviation or maximum amplitude, is obtained from the converted viscosity waveform, and when a certain threshold is exceeded, it is determined as abnormal. In addition, since the viscosity of air and liquid is greatly different, air suction can be identified by setting a lower limit threshold value with an average value of converted viscosity. In the case of clogging or increase in viscosity (due to liquid denaturation, etc.), the average value becomes large and can be identified by setting an upper threshold.

  FIG. 6 shows an example of a flowchart of the operation. First, the set dispensing conditions (nozzle type and the like) are read, and a viscosity conversion formula group obtained in advance corresponding to the conditions and stored in the storage unit is loaded. Next, suction is started and pressure data is acquired by the pressure sensor, and the control unit inputs the acquired pressure data into a viscosity conversion formula to calculate a converted viscosity. This operation is periodically repeated until the end of suction to obtain a converted viscosity waveform. That is, the viscosity is obtained at regular intervals, and the relationship between the elapsed time after the start of suction and the viscosity is obtained. Further, the average value or standard deviation of the obtained converted viscosity waveform, or the average value and the standard deviation are obtained and compared with the above-described abnormality determination threshold value. When the preset threshold value is exceeded, the control unit determines that the abnormality is present. . In this case, it is desirable that the control unit stores the fact that the abnormality is determined in the storage unit, so that the operator can read the information later or output an alarm to the outside to notify the operator. In addition to this, it is desirable to display an alarm on the display unit and record the pressure and the converted viscosity in the storage unit.

  FIG. 7 shows, as an example, viscosity-converted waveforms for a large number of measurement results (total 700) when air is actually sucked by the automatic analyzer 10 or when bubbles or air are intentionally sucked with a liquid having the same composition as the standard liquid. The average value and standard deviation are plotted on a two-dimensional graph. The graph is displayed on the display unit. The horizontal axis represents the converted viscosity average value, and the vertical axis represents the converted viscosity standard deviation. The data with only □ marks are those that are judged to have no abnormalities in absorbance (defined as a case where a certain amount of dye is mixed in a standard solution and optically measured and the absorbance is 90% or more of the set dispensed amount). is there. The x mark data indicates that the absorbance was determined to be abnormal (90% or less of the set dispensing amount), and that the liquid had a high viscosity (glycerin concentration 50%, 60%).

  By calculating the converted viscosity, it can be determined that the air is mainly sucked when the average value is lower than the threshold value on the lower value side, and that the high viscosity liquid (simulating clogging) is sucked when the threshold value is higher than the higher value side. In addition, when the threshold value is equal to or greater than the standard deviation, it can be determined that there is an abnormality because a large number of bubbles are sucked. That is, the threshold value is stored in the storage unit for both the average value and the standard deviation, and the control unit determines that the fluid is normally sucked when both the threshold values are at desired values. On the other hand, when any value is equal to or greater than the stored threshold, the control unit determines that there is an abnormality. In the case of the present embodiment, the average value threshold is 0.0005 Ps · s at low value (near the middle of air and glycerin concentration 0% liquid), and the high value is 0.005 Pa · s (near the middle of glycerin concentrations 40% and 50%). ) And a standard deviation threshold value of 0.0002 Pa · s, it is possible to accurately discriminate between abnormal and normal (in this example, a discrimination accuracy rate of 100%).

  In this embodiment, the case of a pressure change at the time of suction is taken up. However, it is obvious that the pressure change at the time of discharge can be similarly processed, converted into a viscosity, and can be discriminated. Further, the viscosity conversion data used for obtaining the average value and the standard deviation may be two or more, and it is not necessary to have a large number as in this embodiment. In addition, when the amount of suction liquid is different, the part where the waveform drops due to the end of suction changes over time, but if you create a viscosity conversion formula group from the waveform when the liquid volume is the highest, suction can be performed even when the amount of suction liquid is small. What is necessary is just to calculate using the viscosity conversion formula group of the range to the end. Further, when the suction flow rate is different at the time of measurement, since the pressure change is proportional to the flow rate, the conversion formula can be easily corrected. Further, a two-dimensional graph of average values and standard deviations as shown in FIG. 6 is displayed as a graph display 181 as shown in FIG. 1 on a display unit such as the console 18, and liquid viscosity information is given to a person accessing the automatic analyzer 10. It may be shown directly. Also, a person may set or change the threshold value by looking at the graph.

  Example 2 will be described. The present embodiment relates to an invention that makes it easy to identify the cause of an abnormality using the threshold value and observation means set in the first embodiment.

  The present dispensing apparatus includes an observation means for observing a container that contains a fluid. A control part memorize | stores the state of the container observed by the observation means in a memory | storage part, when a standard deviation or an average value becomes more than the threshold value memorize | stored in the memory | storage part. This helps identify the cause of the abnormality as described below. Here, the state of the container indicates the state of the surface or the interior of the fluid, such as whether foreign matter or bubbles are mixed in the fluid stored in the container, and the degree of transparency and turbidity of the fluid.

  For example, the observation means is a camera. The state of the container sucked or discharged by the nozzle is taken as a moving image by the camera, and is always temporarily stored. When the threshold set in the first embodiment is exceeded, the temporarily stored moving image is transferred to the storage unit and stored, so that the operator can perform suction or discharge with a sample that is later determined to be abnormal. Can be confirmed, and the cause determined to be abnormal for the sample determined to be abnormal can be confirmed.

  For example, the observation means is an absorptiometer. As shown in FIG. 1, the automatic analyzer includes a detector 16 that detects absorbance. For this reason, when it becomes more than the threshold memorize | stored in Example 1, it determines with it being abnormal by measuring the light absorbency of the sample exceeding the threshold value, preserve | save the light absorbency in a memory | storage part, and making it link | link. The calculated viscosity and absorbance of the sample are simultaneously read, and the operator can check the cause of the abnormality of the sample determined to be abnormal by checking the absorbance.

  Further, for example, the observation means is a turbidimeter. The dispensing apparatus can detect the turbidity of the sample in the manner of detecting the above-described absorbance by further providing a light source and a detector for measuring scattered light in addition to the absorbance. The operator can check the cause of the abnormality of the sample determined to be abnormal by checking the turbidity.

  The number of observation means may be one, or any one may be combined. When combined, a material for identifying the cause of the abnormality can be obtained from various viewpoints, and the cause of the abnormality can be specified precisely.

  The examples 1 and 2 have been described above. In the present embodiment, the sample and the reagent of the automatic analyzer 10 have been described. However, the present invention is not limited to this, and any liquid may be used as long as it is used for dispensing or moving the liquid. For example, even in the case of application of an adhesive with a dispenser, the converted viscosity can be obtained, and can be used for viscosity control of the adhesive, detection of clogging due to drying, suction of air and bubbles, poor mixing, and the like. Moreover, although the present Example demonstrated the case where the liquid was dispensed, the apparatus which dispenses gas may be sufficient. In that case, mixing of liquid at the time of inhalation is detected (for example, in the case of inhalation of gas that is liable to be liquefied, a cause such as gas being liquefied and sucked into the nozzle tip is considered).

  According to this embodiment, since the time-varying pressure waveform is converted into a constant viscosity, it is not necessary to set a complicated threshold value along the waveform, and changes due to abnormal phenomena such as air, bubbles, clogging, etc. Since it can detect by providing a fixed threshold with respect to a deviation and an average, a process can be simplified. As a result, the speed of anomaly detection can be increased. In addition, since the viscosity itself is obtained, it is possible to detect bubbles and air inhalation and clogging even with a liquid having a viscosity different from that of the standard liquid. In addition, even in an apparatus with different dispensing pipes, inhalation of bubbles and air and clogging can be detected by measuring the pressure with a standard solution for each apparatus.

  In addition, abnormalities can be classified based on the combination of average value and standard deviation, so it is possible to use this information to detect the development of devices that are unlikely to generate bubbles and to detect the inclusion of bubbles and air due to abnormalities such as nozzle breakage. Available. However, some samples have a small surface tension and are less likely to generate bubbles. Therefore, it is not necessary to obtain both the standard deviation and the average value, and only the average value may be obtained and used as a material for determining abnormality detection.

  In addition, since the viscosity information of the sample can be used, it is possible to measure and evaluate the change in blood viscosity due to lifestyle-related diseases. Further, it can be used for confirmation of the viscosity of a liquid such as a reagent and determination of deterioration accompanying a change in viscosity. In addition, in the case of mixed liquids with multiple types of components with different viscosities, if they are not mixed well, the viscosity of the liquid that is sucked and discharged varies depending on the degree, so it can be used for mixing evaluation by looking at only the standard deviation. . In this case, it is not necessary to obtain an average value.

  Since there are two evaluation parameters (average value and standard deviation), the visibility of the operator is improved by showing a two-dimensional graph on the display device. Further, by displaying the viscosity and its variation, the operator can empirically determine abnormalities such as inhalation and clogging of bubbles and air.

DESCRIPTION OF SYMBOLS 10 Automatic analyzer 11 Sample disk 12 Reagent disk 13 Reaction disk 14 Sample dispensing mechanism 15 Reagent dispensing mechanism 16 Detector 17 Control part 18 Console 19 Cleaning mechanism 20 Flow path system 21 of dispensing mechanism Nozzle 22 Syringe pump 23 Tube 24 Plunger 25 Valve 26 Pressure sensor 27 Container 28 Liquid film or foam 101 Stirring mechanism 181 Graph display

Claims (8)

A nozzle for aspirating or discharging fluid;
Pressure generating means for changing the pressure in the nozzle;
A pressure sensor for detecting the pressure in the nozzle;
A storage unit for storing a conversion equation for obtaining a viscosity corresponding to a plurality of time points from pressure values at a plurality of time points of a pressure waveform obtained by the pressure sensor at the time of suction or discharge of a standard solution having a known viscosity;
A controller that calculates the viscosity at each time point from the pressure values at the plurality of time points of the pressure waveform obtained by the pressure sensor at the time of suction or discharge of the fluid of unknown viscosity, using the conversion equation. Dispensing device characterized by. The dispensing device according to claim 1,
The control unit calculates a standard deviation or an average value in one specific fluid sample, with the viscosity at each time point calculated by the calculation means as a population,
The dispensing unit determines whether the standard deviation or the average value exceeds a threshold stored in the storage unit. The dispensing device according to claim 2,
When the standard deviation or the average value is equal to or greater than the threshold, the control unit stores the fact in the storage unit or outputs an alarm to the outside. The dispensing device according to claim 2,
Furthermore, an observation means for observing a container containing a fluid of unknown viscosity is provided,
The control unit stores the state of the container observed by the observation unit in the storage unit when the standard deviation or the average value is equal to or greater than the threshold value. apparatus. The dispensing apparatus according to claim 4, wherein
2. The dispensing apparatus according to claim 1, wherein the observation means is any one of a camera, an absorptiometer, and a turbidimeter. The dispensing device according to claim 1,
The dispensing apparatus further comprises a display unit that displays the time variation of the viscosity calculated by the control unit. The dispensing device according to claim 1,
The control unit calculates a standard deviation and an average value in one specific fluid sample, with the viscosity at each time point calculated by the calculation unit as a population,
A dispensing apparatus comprising a display unit that displays a calculation result on a two-dimensional graph of the standard deviation and the average value. The dispensing device according to claim 7,
In the storage unit, threshold values for the standard deviation and the average value are stored, respectively.
The dispenser is characterized in that the control unit determines that the fluid has been normally sucked or discharged when both of the threshold values of the standard deviation and the average value are in a desired range.