JP2012021892A - Automatic analyzer and dispensation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic analyzer in which the deterioration of processing property is avoided with a simple mechanism as much as possible even in the case in which a biological sample with high viscosity is dispensed by using a sample dispensing mechanism of the automatic analyzer.SOLUTION: In an automatic analyzer according to the present invention having a dispensing probe sucking and discharging samples, a syringe pump generating pressure for sucking and discharging the samples in the dispensing probe, and a flow channel transmitting the pressure generated by the syringe pump to the dispensing probe, a driving amount is imparted to the syringe pump which is larger than the driving amount of the syringe pump for sucking samples in a predetermined amount by the dispensing probe, then the driving amount is set back to the driving amount of the syringe pump for sucking the sample in a predetermined amount.

Description

  The present invention relates to an automatic analyzer, and more particularly to an automatic analyzer that analyzes a biological sample having a high viscosity.

  The automatic analyzer mixes and reacts biological samples such as blood and urine (also called specimens) placed in a reaction container with reagents, irradiates the reaction solution with light after a predetermined time, and converts the absorbance of the passed light into the biological sample. It is an apparatus for calculating the concentration of a specific component contained. In detection using light, a biological sample and a reagent are reacted for a predetermined time in a container called a reaction container. Therefore, the automatic analyzer includes a dispensing mechanism for dispensing a biological sample into a reaction container.

  When dispensing biological samples, the viscosity varies depending on the sample, but as a method of accurately dispensing biological samples with a wide range of viscosities into reaction vessels using this dispensing mechanism, a plurality of different suction port diameters can be used. A method of dispensing using different probes (Patent Document 1), a method of monitoring the pressure in the dispensing channel during sample suction with a pressure gauge installed in the dispensing channel, and making a dispensing method appropriate to that ( Patent Document 2 and Patent Document 3), and a method (Patent Document 4) is known in which the viscosity of a sample is measured with a vibrating viscometer before sample dispensing, and a dispensing method corresponding to the viscosity is selected.

JP-A-6-174603 JP 2001-221805 A JP 2003-28886 A JP 2008-224386 A

  Conventionally, when a component analysis is performed by an automatic analyzer, a biological sample having a specific viscosity of about 10 times or less such as plasma, serum, whole blood, and urine has been aspirated by a dispensing mechanism. However, with the diversification of items for component analysis by automatic analyzers, the types of samples handled have diversified, and there have been cases where samples with higher viscosity than conventional ones are handled. As an example, there is an analysis of measuring the concentration of HbA1c in blood using a blood cell collected by centrifugation in a blood collection tube containing an anticoagulant such as sodium fluoride and sedimented on the bottom of the blood collection tube. In this case, the specific viscosity of the blood cell layer to be aspirated is about several tens to several hundred times, which is about 1 to 2 orders of magnitude higher than that of a conventional aspirated object such as plasma or serum.

  As described above, when the viscosity of the suction target increases by one to two digits, a predetermined amount of sample is sucked into the dispensing probe only by a simple suction operation as described in the techniques described in Patent Documents 2 and 3. This takes time and affects the analytical throughput of the automated analyzer.

  Patent Document 4 discloses a method of measuring the viscosity in advance and performing a sample suction operation and a discharge operation corresponding to the viscosity. However, Patent Document 4 does not specifically describe the sample suction method. Since a special mechanism is required for viscosity measurement, the apparatus becomes complicated.

  On the other hand, as described in Patent Document 1, when the viscosity range of the suction target is different by 1 to 2 digits, the suction target is sucked by a predetermined amount by using a plurality of probes having different suction port diameters depending on the suction target. Although there is also a technique, there is no specific description of the sample suction method in Patent Document 1, and the dispensing mechanism includes a plurality of probes, which complicates the apparatus.

  An object of the present invention is to provide an automatic analyzer that prevents a reduction in processing capacity as much as possible with a simple mechanism even when a sample having a high viscosity of a biological sample is dispensed by a sample dispensing mechanism of the automatic analyzer. .

  In the present invention, a dispensing probe that sucks and discharges a sample, a syringe pump that generates pressure for causing the dispensing probe to suck and discharge the sample, and a flow path that transmits the pressure generated by the syringe pump to the dispensing probe In the automatic analyzer including the above, after the driving amount larger than the driving amount of the syringe pump for sucking the predetermined amount of sample by the dispensing probe is given to the syringe pump, Provided is an automatic analyzer characterized by returning to a driving amount of a syringe pump for performing suction.

  According to the present invention, when the viscosity of the biological sample to be analyzed (suction target) reaches a wide range (specifically, the specific viscosity with respect to water is about 10 times or less to several hundred times) in the automatic analyzer. However, it can be dispensed by a simpler mechanism than the prior art.

Schematic of the dispensing mechanism of the automatic analyzer. Description of the dispensing method according to the present invention. Schematic of an automatic analyzer.

  First, an outline of the automatic analyzer will be described with reference to FIG.

  The automatic analyzer is divided into a sample erection unit and a reaction unit. In the sample erection unit, samples such as serum and urine collected in the sample container 201 are erected on the sample disk 202 and discharged from the sample container 201 to the reaction container 204 by the sample dispensing mechanism 203. The reaction container 204 is arranged on the circumference of the reaction disk 205 in the reaction section. When the reaction disk 205 rotates, the reaction container 204 into which the sample is dispensed moves to the reagent addition position, and the reagent disk The reagent is added from the reagent container 207 set in 206 by the reagent dispensing mechanism 208. The reaction vessel 204 to which the reagent has been added moves to the stirring position as the reaction disk 205 rotates, and the reaction solution is stirred by the stirring mechanism 209. The reaction vessel 204 containing the reaction solution passes through the optical axis of the photometer 210 at regular intervals by the rotation of the reaction disk 205, and the absorbance is measured each time. From the measured absorbance, the concentration of the target component in the sample is calculated, and the result is output. The used reaction vessel 204 is washed by the reaction vessel washing mechanism 211 and used for the next measurement.

  Next, the outline of the dispensing mechanism of the automatic analyzer will be described with reference to FIG.

  The dispensing probe 1 is connected to a syringe pump 3 via a flow path 2, and the inside thereof is filled with a liquid. The syringe pump 3 includes a cylinder 3a and a plunger 3b. The sample suction and discharge operations performed at the tip of the dispensing probe 1 are performed by driving the plunger 3b up and down by an actuator or the like. The dispensing probe is moved to a predetermined position by using the dispensing probe transfer means 4.

  As a general sample dispensing method in the automatic analyzer, a syringe pump is lowered after the dispensing probe 1 is lowered by the dispensing probe transfer means 4 and the tip of the dispensing probe 1 is immersed in the sample 6 in the sample container 5. 3 is operated to suck a predetermined amount of sample from the tip of the dispensing probe 1. After the sample is aspirated, the dispensing probe transfer means 4 moves the dispensing probe 1 to the sample discharge position (at this time, the tip of the dispensing probe is separated from the sample), the syringe pump 3 is operated, and the tip of the dispensing probe 1 is moved. A predetermined amount of the sample is discharged from. The syringe pump 3 is driven by a control device such as a computer.

  After completion of the dispensing operation, the dispensing probe 1 can be washed by supplying the liquid 9 filled in the dispensing probe to the syringe pump from the tank 8 at a high pressure by the pump 7 as necessary. Is possible. The switching is performed by the electromagnetic valve 10.

  The present invention will be described below. The present invention can be applied to the specimen dispensing mechanism 203 in FIG. 3, but can also be applied to suction of highly viscous samples and reagents.

  With reference to FIG. 2, a description will be given of an operation example in which a sample having a high viscosity (specific viscosity of water such as blood cells is about 10 to several hundred times) is sucked in the sample dispensing mechanism of the automatic analyzer shown in FIG. . As a sample, blood cells obtained by centrifuging blood collected in a decision tube containing an anticoagulant and settling on the bottom of the blood collection tube are targeted.

  After the dispensing probe 1 is lowered by the dispensing probe transfer means 4, the syringe pump 3 is operated so as to aspirate more than the desired dispensing amount after the tip of the dispensing probe 1 is immersed in the sample 6 to be aspirated. ((A) → (B) in FIG. 2). Next, the syringe pump 3 is operated so as to return the excessive suction amount to the sample side ((B) → (C) in FIG. 2). Further, the dispensing probe transfer means 4 moves the dispensing probe 1 to the sample discharge position (at this time, the tip of the dispensing probe is separated from the sample), the syringe pump 3 is operated, and a predetermined amount from the tip of the dispensing probe 1 is reached. The sample is discharged. At this time, the desired dispensing amount is the amount indicated by 11 in FIG. 2, and the excessive suction is the amount indicated by 12 in FIG. However, since the viscosity of the sample is high, the sample is not filled up to this region.

  In this way, if the syringe pump 3 is controlled so as to draw a surplus more than the desired dispensing amount, the suction pressure at the tip of the dispensing probe 1 increases, and the sample suction speed increases compared to the case where no surplus suction is performed. It is easy to imagine that the sample suction time will be shortened. The reason why the syringe pump 3 is controlled to push back the excess suction is to return the increased suction pressure as soon as possible. If the timing for returning the syringe pump 3 is just before the predetermined dispensing amount is sucked, the suction time is the shortest.

  When the viscosity of the sample to be dispensed is low, there is little delay in the amount of sample actually sucked from the tip of the dispensing probe 1 with respect to the amount of suction operation of the syringe pump 3 without excessive suction. However, when the viscosity of the sample is high (when a sample having a specific viscosity of about 10 to several hundred times with respect to water, such as blood cells, is sucked), the tip of the dispensing probe 1 is actually compared to the suction operation amount of the syringe pump. In this case, the suction operation shown in FIG. 2 is used, so that the sample suction time for the desired dispensing amount is shortened compared to a simple suction-only operation. Is possible.

  In particular, when the desired dispensing volume is 1.5 μl or more, the start time of the return operation for the excess suction volume in the syringe pump 3 is greater than the desired dispensing volume, and the surplus suction volume in the syringe pump 3 is started. If the time is used as the starting point after 0.5 seconds, a highly viscous sample can be sucked more effectively.

  In the present invention, the control device for driving the syringe pump 3 performs the dispensing operation by the sample dispensing mechanism for low-viscosity samples and high-viscosity samples depending on the analysis item and specimen type (serum, plasma, urine, etc.). A function of switching between and may be provided.

DESCRIPTION OF SYMBOLS 1 Dispensing probe 2 Flow path 3 Syringe pump 3a Cylinder 3b Plunger 4 Dispensing probe transfer means 5 Sample container 6 Sample 7 Pump 8 Tank 9 Liquid 10 Solenoid valve 11 Desired dispensing amount 12 Surplus suction 100 Probe tip 101 Probe tip Other than 201 Sample container 202 Sample disk 203 Sample dispensing mechanism 204 Reaction container 205 Reaction disk 206 Reagent disk 207 Reagent container 208 Reagent dispensing mechanism 209 Stirring mechanism 210 Photometer 211 Reaction container cleaning mechanism

Claims (5)

A dispensing probe that sucks and discharges a sample, a syringe pump that generates pressure for causing the dispensing probe to suck and discharge the sample, and a flow path that transmits the pressure generated by the syringe pump to the dispensing probe In automatic analyzers,
Driving the syringe pump for sucking the predetermined amount of sample after giving the syringe pump a driving amount larger than the driving amount of the syringe pump for sucking the predetermined amount of sample by the dispensing probe Automatic analyzer characterized by returning to quantity. The automatic analyzer according to claim 1,
The automatic analyzer is characterized in that the sample has a non-viscosity of at least 10 times as much as water. The automatic analyzer according to claim 1,
2. The automatic analyzer according to claim 1, wherein the sample is a blood cell obtained by centrifuging blood collected in a decision tube containing an anticoagulant and settling on the bottom of the blood collection tube. The automatic analyzer according to claim 1,
To suck the predetermined amount of sample after 0.5 seconds after the syringe pump is given a driving amount larger than the driving amount of the syringe pump for sucking the predetermined amount of sample by the dispensing probe. The automatic analyzer is returned to the drive amount of the syringe pump. A dispensing probe that sucks and discharges a sample, a syringe pump that generates pressure for causing the dispensing probe to suck and discharge the sample, and a flow path that transmits the pressure generated by the syringe pump to the dispensing probe In automatic analyzers,
Driving the syringe pump for sucking the predetermined amount of sample after giving the syringe pump a driving amount larger than the driving amount of the syringe pump for sucking the predetermined amount of sample by the dispensing probe A control device that performs a control to switch between a first driving operation to return the amount and a second driving operation to give a driving amount of a syringe pump for sucking a predetermined amount of sample by the dispensing probe to the syringe pump An automatic analyzer characterized by comprising:

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