JP2009257990A - Liquid-dispensing device for automatic analysis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic analysis apparatus having a liquid dispensing mechanism that accurately dispenses minute liquid and performs dispensation of a large volume. <P>SOLUTION: The volume of a dispensation channel is reduced, by building a small and lightweight dispensation pump for minute amount for sucking and delivering the minute liquid, and the minute inspection liquid can be accurately dispensed, by reducing the expansion or contraction due to the temperature variation in the liquid and in the air in the flow channel. By combining the dispensation pump for minute amount and a dispensation pump for large volume, a wide amount of dispensation, from the minute amount to the large volume, can be handled. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid dispensing apparatus for automatic analysis used in an automatic analyzer. The automatic analysis liquid dispensing device has a dispensing function in which test liquids, including sample liquids, reagent liquids, and washing liquids, are aspirated and discharged using a dispensing pump. Is required to be dispensed.

  The automatic analyzer is required to have a high dispensing volume accuracy of the sample liquid / reagent liquid.

  In particular, in recent years, there has been a demand for reducing the amount of sample liquid and reagent solution consumed and reducing analysis costs. However, in such a small amount of analysis, an error in the amount of sample liquid or reagent solution added to the measurement results. The impact is even greater.

  While it is necessary to reduce the amount of sample liquid and reagent solution, there are some analysis items that are difficult to reduce the amount of sample liquid and reagent solution. Is required.

  In general dispensing systems, there is one in which one syringe included in a dispensing pump is connected to one dispensing probe. In addition, as described in JP-A-5-281240, a small volume syringe (small volume dispensing pump) and a large volume syringe (large volume dispensing pump) are provided for one dispensing probe. There is a combined dispensing system.

JP-A-5-281240

  However, when performing minute dispensing, there is a problem that the dispensing amount varies, the dispensing amount accuracy is remarkably deteriorated, and stable accuracy cannot be obtained.

  That is, in a minute dispensing of 1 μL or less, a volume change due to a temperature change of a part such as water that fills the inside of the dispensing channel and the components that form the dispensing channel from the dispensing pump to the dispensing probe, and The effect of volume change due to suction pressure and discharge pressure cannot be ignored.

  In particular, there is a problem that the volume of the dispensing flow path changes due to the influence of the ambient temperature between the completion of the suction of the test liquid and the completion of the discharge, and the discharge amount becomes inaccurate.

  For example, if the volume of the dispensing channel is reduced by ΔV after the inspection liquid is sucked into the dispensing probe, the inspection liquid in the dispensing probe moves to the syringe side, and ΔV at the tip of the dispensing probe. Is replaced by air. When the test liquid is discharged in this state, the discharge amount is reduced by ΔV. That is, the volume change due to the influence of the ambient temperature appears as it is as an error in dispensing.

  Therefore, it is necessary to reduce the volume change amount of the dispensing channel.

  In view of the above problems, the present invention provides a liquid dispensing apparatus for automatic analysis that can reduce a change in volume of a dispensing flow path and reduce a change in the discharge amount of a test liquid due to the influence of an ambient temperature. With the goal.

  The present invention provides a liquid dispensing apparatus for automatic analysis, comprising: a dispensing arm; an arm driving unit that vertically and rotationally moves the dispensing arm; and a dispensing probe provided on the dispensing arm. A dispensing pump communicating with the probe is provided in the dispensing arm.

  According to the present invention, by providing the dispensing pump on the dispensing arm, the length of the dispensing channel from the dispensing probe to the dispensing pump is shortened, and the volume of the dispensing channel is reduced. For this reason, it becomes possible to dispense a minute amount of a test solution (specimen solution or reagent solution) with high accuracy.

  As a result, analysis using a small amount of test liquid becomes possible, and the test liquid can be reduced.

  In addition, a large-volume dispensing pump can be provided by providing a large-capacity dispensing pump. As a result, it is possible to realize a large volume dispensing from a small amount dispensing, and to cope with various measurements.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a schematic configuration of an automatic analyzer according to an embodiment of the present invention.

  The automatic analyzer includes a reaction disk 4, a reaction container 5, a sample disk 102, a specimen container 101, a reagent disk 125, a reagent bottle 112, a sample dispensing mechanism 1, a reagent dispensing mechanism 110, a stirring mechanism 113, and a luminous intensity. A total 115, a light source lamp 114, and a reaction vessel cleaning mechanism 119 are provided.

  The automatic analyzer further includes a computer 103, an interface 104, a sample dispensing pump 107, a reagent dispensing pump 111, an A / D converter 116, a printer 117, and a CRT 118.

  The automatic analyzer further includes a reaction container cleaning mechanism 119, a cleaning pump 120, a keyboard 121, a memory 122, a reagent disk 125, a liquid level detection circuit 151, a pressure sensor 152, and a pressure detection circuit 153.

  The sample dispensing mechanism 1 and the reagent dispensing mechanism 110 have a configuration as shown in FIG. The same dispensing mechanism is provided for both the sample and the reagent.

  As shown in FIG. 2, the sample dispensing mechanism 1 includes a sample dispensing arm 2, and an arm driving unit 20 that vertically moves and rotates the dispensing arm 2. The dispensing arm 2 includes a dispensing probe 3, a minute amount dispensing pump 12, a minute amount electromagnetic valve 13, and an internal connection tube 11.

  The internal connection tube 11 is connected so that the inlet side of the dispensing probe 3 communicates with the discharge port side of the minute volume dispensing pump 12. The connection tube 11 is made of a flexible synthetic resin. The dispensing probe 3 is made of stainless steel. The minute quantity dispensing pump 12 uses a syringe pump. The syringe pump has a cylinder and a plunger that reciprocates in the cylinder.

  The minute amount electromagnetic valve 13 is connected to communicate with the suction port side of the minute amount dispensing pump 12. The large-capacity dispensing pump 15 is placed outside the dispensing mechanism 1. The external connection tube 14 is connected so that the discharge port side of the large-capacity dispensing pump 15 communicates with the inlet side of the minute volume electromagnetic valve 13.

  The large capacity solenoid valve 16 is connected to communicate with the suction port side of the large capacity dispensing pump 15. The inlet side of the large capacity solenoid valve 16 is connected to the cleaning liquid tank via a tube or the like.

  The dispensing amount of the minute volume dispensing pump 12 is (0.01-5) μL. The dispensing volume of the large-capacity dispensing pump 15 is (5-35) μL.

  The large-capacity dispensing pump 15 corresponds to the sample dispensing pump 107 and the reagent dispensing pump 111 described above.

  Next, before explaining the operation related to the dispensing by the minute amount dispensing pump 12, the dispensing operation by the sample dispensing pump 107 and the reagent dispensing pump 111 will be described.

  Now, using the dispensing probe 3 attached to the sample dispensing arm 2, the sample in the sample container 101 arranged on the sample disk 102 rotating left and right shown in FIG. It is comprised so that it may discharge.

  As can be seen from FIG. 1, the specimen container 101 is placed on the sample disk 102 in a universal arrangement in which the specimen container 101 can be placed directly on the sample disk 102 or on the test tube (not shown). In general, a structure that can cope with the above is applicable.

  In the reagent disk 125, dispensing is performed using the reagent dispensing mechanism 110.

  On the rotatable reagent disk 125, reagent bottles 112 corresponding to a plurality of analysis items to be analyzed are arranged. The reagent dispensing probe attached to the dispensing arm dispenses a predetermined amount of reagent solution from the reagent bottle 112 to the reaction vessel 5.

  The sample dispensing probe 3 performs a sample suction operation and a discharge operation in accordance with the operation of the sample dispensing pump 107. The reagent dispensing probe performs a reagent liquid suction operation and a discharge operation in accordance with the operation of the reagent dispensing pump 111. An analysis item to be analyzed for each sample liquid is input from an input device such as a keyboard 121 or a CRT 118 screen. The operation of each unit in this automatic analyzer is controlled by the control function of the computer 103.

  With the intermittent rotation of the sample disk 102, the sample container 101 is transferred to the sample suction position, and the sample dispensing probe 3 is lowered into the stopped sample container. When the tip of the sample dispensing probe 3 comes into contact with the liquid level of the sample liquid in accordance with the lowering operation, a detection signal is output from the liquid level detection circuit 151, and based on this, the computer 103 is connected to the drive unit of the dispensing arm 2. Control to stop the descent operation.

  Next, after a predetermined amount of sample liquid is sucked into the dispensing probe 3, the dispensing probe 3 rises to the top dead center. While the dispensing probe 3 is sucking a predetermined amount of the sample liquid, a pressure fluctuation occurs between the dispensing probe 3 and the dispensing flow path of the sample dispensing pump 107.

  The pressure fluctuation in the dispensing flow channel during the suction operation is monitored by the pressure detection circuit 153 using a signal from the pressure sensor 152, and if an abnormality is found in the pressure fluctuation during the suction, there is a possibility that a predetermined amount is not sucked. Therefore, an alarm is added to the analysis data.

  Next, the dispensing arm 2 pivots horizontally, the sample dispensing probe 3 is lowered at the position of the reaction vessel 5 on the reaction disk 4, and the specimen liquid held in the reaction vessel 5 is discharged. When the reaction container 5 containing the sample liquid is moved to the reagent addition position, a reagent corresponding to the corresponding analysis item is added from the reagent dispensing probe.

  As the sample and reagent are dispensed, the sample liquid in the sample container 101 and the liquid level of the reagent in the reagent bottle 112 are detected. The mixture in the reaction container to which the sample liquid and the reagent are added is stirred by the stirrer 113. The reaction container containing the mixture is transferred to the photometer 115, and the luminescence value or absorbance of each mixture is measured by a photomultiplier tube or photometer as a measuring means. The light emission signal or light reception signal enters the computer 103 via the interface 104 via the A / D converter 116, and the concentration of the analysis item is calculated. The analysis result is printed out to the printer 117 via the interface 104 or output to the CRT 118 and stored in the memory 122. After completion of photometry, the reaction vessel 5 is washed at the position of the reaction vessel washing mechanism 119. The cleaning pump 120 supplies cleaning water to the reaction container and discharges waste liquid from the reaction container. In the example of FIG. 1, three rows of container holders are formed so that three rows of sample containers 101 can be set concentrically on the sample disk 102, and the sample liquid suction positions by the sample dispensing probes 3 are respectively set. One is set in each column.

  The above is the description of the operation in which dispensing is performed by the sample dispensing pump 107 and the reagent dispensing pump 111 without using the minute volume dispensing pump 12.

  Next, dispensing related to the dispensing pump 12 for a small amount will be described.

  The minute volume dispensing pump 12 can be reduced in size and weight by setting the maximum dispensing volume to several μL, and as a result, can be arranged inside the dispensing arm 2. Further, since it operates only for minute dispensing, the stroke of the plunger is extremely short, the life of the consumable seal part is extended, and the replacement frequency can be reduced.

  That is, the small-volume dispensing pump 12 is small and light, and does not require frequent replacement of seal parts. Therefore, the dispensing probe and the dispensing pump can be arranged even if the dispensing arm 2 is narrow. it can. Thereby, the dispensing channel from the dispensing probe to the dispensing pump is shortened, and the volume of the dispensing channel is reduced. For this reason, the test liquid (sample liquid or reagent liquid) can be dispensed with a predetermined minute amount with high accuracy. As a result, analysis using a small amount of test liquid becomes possible, and the test liquid can be reduced.

  Next, the dispensing operation will be described with reference to the dispensing operation time charts shown in FIGS. 4, 5, and 6.

  First, the procedure for large-volume dispensing shown in FIG. 4 will be described.

  The minute volume solenoid valve 13 is opened, the large volume solenoid valve 16 is closed, and the large volume dispensing pump 15 is operated to suck and discharge the sample liquid with the sample probe 3. At this time, the large-capacity dispensing pump 15 and the minute-volume dispensing pump 12 may be operated together.

  By this dispensing, a large volume dispensing with a dispensing amount of (5-35) μL can be performed.

  The procedure for microdispensing shown in FIG. 5 will be described.

  The sample dispensing probe 3 sucks and discharges the sample liquid by closing the minute amount electromagnetic valve 13 and operating the minute amount dispensing pump 12. At this time, the large capacity solenoid valve 16 may be open or closed. At this time, the dispensing flow path is cut off from the connection tube 14 and the large-capacity dispensing pump 15 due to the blockage of the minute amount electromagnetic valve 13, so that the necessary flow path volume is obtained.

  By this dispensing, it is possible to accurately dispense a differential amount of (0.01-5) μL.

  The procedure for minute dispensing shown in FIG. 6 will be described.

  This minute dispensing is a case where a large volume is aspirated and dispensed in a small amount for the purpose of preventing thinning of the specimen liquid inside the sample dispensing probe 3.

  The minute volume solenoid valve 13 is opened, the large volume solenoid valve 16 is closed, and suction is performed by the large volume dispensing pump 15 and the minute volume dispensing pump 12. After the suction, the minute amount electromagnetic valve 13 is closed and discharged by the minute amount dispensing pump 12.

  Alternatively, after the minute volume dispensing pump 12 is in the suction state, the minute volume electromagnetic valve 13 is opened, the large volume electromagnetic valve 16 is closed and sucked by the large volume dispensing pump 15, and then the minute volume electromagnetic valve 13 is opened. Then, the minute amount dispensing pump 12 discharges.

  The inside (dispensing flow path) of the dispensing probe 3 is filled with a fluid such as water. The fluid and the sample liquid are separated by interposing a slight air reservoir between the fluid and the sample liquid sucked at the tip of the dispensing probe 3. However, I dislike that fluid components are mixed in the sample liquid near the air reservoir.

  Therefore, the sample liquid is used only for the analysis measurement at a position very close to the tip of the dispensing probe 3, and the remaining sample liquid mixed with the fluid component is discharged by the large-capacity dispensing pump 15, thereby further improving the measurement accuracy. be able to.

  By following the dispensing procedure as described above, a wide range of dispensing from a large volume to a very small amount can be provided. In addition, in the minute amount dispensing, the accuracy of the dispensing amount becomes extremely high, so that the accuracy of the analytical measurement can be improved.

  As mentioned in the above “Problems to be Solved by the Invention”, the volume fluctuation amount of the dispensing flow path that occurs during the period from the aspiration of the sample liquid to the discharge appears as an error in the discharge amount as it is.

  A connection tube of a syringe (dispensing pump) which is a part of the dispensing channel and a sample dispensing probe will be described as an example.

  That is, the connecting tube has a diameter of 1.5 mm and a length of 1 m. When the connecting tube is filled with 20 ° C. water and the temperature of the water changes by 0.1 ° C., the dispensing error amount is 0.037 μL when calculated as the volume expansion coefficient of water 0.00021 / ° C. It becomes. When this error amount is expressed as a ratio to the dispensed amount, an error of 2.5% is obtained when the 1.5 μL is dispensed, and an error of 7.5% is obtained when the 0.5 μL is dispensed.

  As described above, in the embodiment of the present invention, the length of the connection tube can be greatly shortened. For example, when the length of the connection tube is shortened to 10 cm, even if 0.5 μL is dispensed, the error is 0.75%. Can be suppressed.

  Since the dispensing flow path excluding the sample dispensing probe 3 is closed inside the dispensing arm 2, it is less susceptible to the influence of the ambient temperature, which causes a decrease in the accuracy of minute dispensing.

  In addition, since the volume of the dispensing channel can be significantly reduced, the amount of volume change due to the suction and discharge pressures of the fluid filled in the dispensing channel can be reduced.

  Further, since the dispensing flow path is compact, the structure is advantageous for reducing the thermal effect such as covering the dispensing flow path with a heat insulating material.

  In addition, since the dispensing flow path is compact, it is an advantageous structure when the temperature control of the flow path is performed for the purpose of improving the accuracy of minute volume dispensing.

  Further, by arranging the minute amount dispensing pump 12 and the minute amount electromagnetic valve 13 in the vicinity of the rotation axis of the dispensing arm 2, an increase in the moment of inertia of the dispensing arm 2 can be suppressed and the demand for high speed operation can be met.

  Another embodiment shown in FIGS. 3 and 8 will be described.

  In this embodiment, the volume of the dispensing channel is further reduced.

  By integrating the sample dispensing probe 3, the minute amount dispensing pump 12, and the minute amount electromagnetic valve 13 without using a connecting tube, the volume of the dispensing flow path can be further reduced, and the amount can be further reduced. realizable.

  As shown in FIG. 8, the dispensing probe 3 is fastened by a fastening fitting 1210 that is screwed to the discharge port 1200 of the cylinder of the minute quantity dispensing pump 12. It is also possible to form a screw thread at the base of the dispensing probe and to screw the dispensing probe into the minute quantity dispensing pump 12.

  FIG. 7 shows a specific configuration of the minute volume dispensing pump 12 shown in FIG.

  The minute volume dispensing pump 12 includes a pump unit 1300, a rotary motion / reciprocating motion conversion mechanism unit 1310, and a drive motor unit 1320. The pump unit 1300 is disposed above, and the rotary motion / reciprocating motion conversion mechanism unit 1310 is disposed intermediately. The drive motor unit 1320 is placed below and arranged vertically.

  The cylinder 1330 of the pump unit 1300 is provided with a plunger 1340 that reciprocates. The connection tube 11 is fastened so as to communicate with a discharge port provided in the upper part of the cylinder 1330. The minute amount electromagnetic valve 13 is fastened so as to communicate with the side portion of the cylinder 1330.

  The drive motor unit 1320 drives the rotary motion / reciprocating motion conversion mechanism unit 1310. The rotary motion / reciprocating motion conversion mechanism 1310 causes the plunger 1340 to reciprocate in the vertical direction. By the reciprocating operation of the plunger 1340, the pump unit 1300 performs the suction and discharge operations.

  The syringe pump unit 1300 includes the plunger seal part as described above, but mainly operates only for a minute amount of dispensing. Therefore, the stroke of the plunger is extremely short, and the life of the seal part, which is a consumable, is extended, and the replacement frequency is increased. Can be reduced.

  In addition, since the minute volume dispensing pump 12 is reduced in size and weight, it can be arranged even in a slightly narrower dispensing arm where the mechanical equipment is dense.

The figure which concerns on the Example of this invention and shows schematic structure of an automatic analyzer. The figure which concerns on the Example of this invention and showed the dispensing flow path structure of the dispensing mechanism for samples and a reagent. The figure which concerns on the other Example of this invention, and showed the dispensing flow path structure of the dispensing mechanism for samples and a reagent. The figure which concerns on the Example of this invention and shows the operation | movement time chart of large volume dispensing. The figure which concerns on the Example of this invention and shows a trace amount dispensing operation | movement time chart. The figure which concerns on the Example of this invention, and shows the time chart when the suction amount and the discharge amount differ. The figure which concerns on the Example of this invention and shows the specific structure of the dispensing pump for traces shown in FIG. The figure which concerns on the other Example of this invention, and shows the structure which fastens the dispensing probe shown in FIG. 3 to the discharge port of a cylinder with a fastener.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Dispensing mechanism, 2 ... Dispensing arm, 3 ... Dispensing probe for samples, 4 ... Reaction disk, 5 ... Reaction container, 11 ... Connection pipe, 12 ... Dispensing pump for trace amount, 13 ... Solenoid valve for minute amount , 14 ... Connecting pipe, 15 ... Large volume dispensing pump, 16 ... Large volume solenoid valve, 101 ... Sample container, 102 ... Sample disk, 103 ... Computer, 104 ... Interface, 107 ... Sample dispensing pump, 110 ... Reagent dispensing probe, 111 ... Reagent dispensing pump, 112 ... Reagent bottle, 113 ... Stirring mechanism, 114 ... Light source lamp, 115 ... Photometer, 116 ... A / D converter, 117 ... Printer, 118 ... CRT, 119 ... reaction vessel cleaning mechanism, 120 ... washing pump, 121 ... keyboard, 122 ... memory, 125 ... reagent disk, 151 ... liquid level detection circuit, 152 ... pressure sensor Sa, 153 ... pressure detection circuit.

Claims (12)

In a liquid dispensing apparatus for automatic analysis having a dispensing arm, an arm driving unit that vertically and rotationally moves the dispensing arm, and a dispensing probe provided in the dispensing arm,
A liquid dispensing apparatus for automatic analysis, wherein a dispensing pump communicating with the dispensing probe is provided in the dispensing arm. In the liquid dispensing device for automatic analysis according to claim 1,
The liquid dispensing apparatus for automatic analysis, wherein the dispensing probe is connected to a discharge port of the dispensing pump without a connection tube. In the liquid dispensing device for automatic analysis according to claim 1 or 2,
The dispensing pump has a configuration in which a pump unit placed above, a rotary motion / reciprocating motion conversion mechanism unit placed in the middle, and a drive motor unit placed below are arranged vertically. Liquid dispensing device. In the liquid dispensing device for automatic analysis according to claim 3,
The liquid dispensing apparatus for automatic analysis, wherein the pump part has a discharge port in an upper part. In a liquid dispensing apparatus for automatic analysis having a dispensing arm, an arm driving unit that vertically and rotationally moves the dispensing arm, and a dispensing probe provided in the dispensing arm,
A dispensing pump for a small amount communicating with the dispensing probe is provided in the dispensing arm,
A liquid dispensing apparatus for automatic analysis, comprising a large-capacity dispensing pump communicating with the dispensing probe. In the liquid dispensing device for automatic analysis according to claim 5,
The automatic dispensing liquid dispensing apparatus, wherein the dispensing probe, the minute volume dispensing pump, and the large volume dispensing pump communicate in series with the minute volume dispensing pump interposed therebetween. The liquid dispensing device for automatic analysis according to claim 5 or 6,
A liquid component for automatic analysis, comprising: a small volume solenoid valve communicating with the suction port side of the small volume dispensing pump; and a large volume solenoid valve communicating with the suction port side of the large volume dispensing pump. Note device. In the liquid dispensing device for automatic analysis according to claim 7,
It has a control function that opens the minute volume solenoid valve, closes the large volume solenoid valve, and operates the large volume dispensing pump to cause the dispensing probe to suck and discharge the test solution. Liquid dispensing device for automatic analysis. The liquid dispensing apparatus for automatic analysis according to claim 8,
A liquid dispensing apparatus for automatic analysis, which has a control function for operating the minute volume dispensing pump together with the large volume dispensing pump. In the liquid dispensing device for automatic analysis according to claim 7,
An automatic analysis liquid dispensing apparatus having a control function of closing the minute amount electromagnetic valve and operating the minute amount dispensing pump to cause the dispensing probe to suck and discharge the test solution. In the liquid dispensing device for automatic analysis according to claim 7,
Open the minute volume solenoid valve, close the large volume solenoid valve, operate the large volume dispensing pump and the minute volume dispensing pump, and draw the test solution into the dispensing probe. A liquid dispensing apparatus for automatic analysis, which has a control function for closing a solenoid valve and operating a minute volume dispensing pump to discharge a test liquid from a dispensing probe. The liquid dispensing apparatus according to claim 7, wherein
Opening the minute volume solenoid valve, closing the large volume solenoid valve, operating the large volume dispensing pump to suck the test solution into the dispensing probe, the minute volume previously held in the suction state A liquid dispensing apparatus for automatic analysis, which has a control function of operating a dispensing pump in a discharge state and discharging a test liquid from the dispensing probe.

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