JPH05288757A - Automatic analyzer - Google Patents

Abstract

PURPOSE:To obtain an automatic analyzer which can correctly calculate the distributing amount of a specimen or the like from the working amount, etc., of a sampling pump and correct the data value as the measuring result to a suitable value on the basis of the calculating value. CONSTITUTION:The operation of a sampling pump or the like is detected by a sensor 5, which is monitored in terms of the working amount by a working amount monitor means 22. The distributing amount of a specimen or the like is calculated by a distributing amount calculating means 23 based on the working amount. The data of tone absorbance or the like as the measuring result is corrected to a suitable value by a data correcting means 25 corresponding to the calculated distributing amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic analyzer, and more particularly to improvement of its sampling system.

[0002]

2. Description of the Related Art Generally, in automatic analyzers such as biochemical analyzers and immunoassay devices, a minimum amount of sample is dispensed by high precision microdispensing technology in order to reduce the burden on the subject and the amount of reagent. Amount of 2 μl / test and accuracy of CV ≦ 1% are realized.

CV (%) = (average value of measured values / standard deviation of measured values) × 100 In order to achieve such dispensing accuracy, in recent years, in order to improve the accuracy of each component of the apparatus. Is actively being developed. For example, improvement of operation accuracy in syringe and sampling pump drive system, prevention of pressure loss in pressure transmission system from syringe to pipette probe,
Techniques such as speeding up response in valves and the like can be mentioned.

[0004]

However, in order to improve the accuracy of each component of the apparatus to the limit by the above means, there are many technical difficulties, and there is a problem that it is a main cause of cost increase of the apparatus itself. .. Further, in order to dispense the dispensed amount exactly as instructed from the tip of the pipette probe, it is necessary to provide a large number of various sensors and the like in the device, and as a result, the device cannot be downsized. There's a problem.

The present invention has been made in order to solve these problems, and provides an automatic analyzer capable of reducing the cost and size of the apparatus and obtaining an accurate measurement value. With the goal.

[0006]

The automatic analyzer according to the present invention operates by operating a sampling pump,
In an automatic analyzer that measures a chemical reaction by aspirating a predetermined amount of reagent or sample that has been commanded beforehand into a pipette probe, and dispensing these solutions into a reaction tube, a sensor that detects the operation of the sampling pump and a sensor from the sensor Operation amount monitor means for monitoring the operation amount of the sampling pump based on the output signal, dispensing amount calculation means for calculating the dispensing amount from this operation amount, and the measured data is corrected in correspondence with the calculated dispensing amount. And a data correction means for performing the correction.

[0007]

In the automatic analyzer of the above means, when the sampling pump operates, the sensor detects it, and the operation amount monitor means determines the operation amount of the sampling pump to obtain accurate operation amount information. Next, after the dispensed amount calculating means calculates the dispensed amount dispensed into the reaction tube based on the operation amount information, the data correction means calculates the dispensed amount and the absorbance based on the proportional relationship in FIG. Then, the data value is corrected. Therefore, it is possible to obtain highly accurate inspection data even if the dispensed amount of the sample changes to some extent.

[0008]

[Examples] Generally, in an automatic analyzer, a certain amount of sample and a certain amount of reagent are mixed and stirred, and then reacted for a predetermined time, the concentration of the product is measured by the absorbance, and the calibration curve or Factor obtained in advance is used. Then, the concentration of the substance to be measured in the sample is obtained. At this time, the concentration of the substance A to be measured in the sample is obtained by the following formula.

When the substance to be measured is an enzyme and its activity value is obtained, it can be obtained by the following formula.

(IU) / l = F × ΔAbS (1) F = 1 / ε × (TV) / (SV) × 1000 (2) At this time, (IU) / l : Enzyme activity value in sample ΔAbS: Change in absorbance of reaction solution per unit time ε: Molecular extinction coefficient of absorbance changing substance (substrate) SV: Sample amount TV: Total reaction liquid (sample + reagent) amount Also measured When a substance is a biochemical substance and its concentration is to be obtained, it can be obtained by the following formula.

[A] = ΔE × F ′ × (SV) / (TV) (3) F ′ = [std] / (ΔE _STD ) × (TV _STD ) / (SV _STD ) ... (4) At this time, [A]: substance concentration in sample (known) ΔE: absorbance of reaction solution (or absorbance change amount per unit time) [std]: substance concentration in standard solution (known) ΔE _STD : Absorbance of reaction solution when measuring standard solution (or change in absorbance per unit time) SV _STD : Standard solution volume when measuring standard solution TV _STD : Total reaction solution (standard solution + reagent) volume when measuring standard solution , The cause of the error of the measured value is the sample amount (S
V) and the amount of reagent. When these change, the total reaction liquid amount (TV) also changes, which affects the measured value.

Therefore, in the past, the whole measurement accuracy was emphasized by how accurately these materials could be dispensed, and a highly accurate pump was required.

However, even if the amount of sample and / or reagent dispensed each time is slightly different, if the amount can be known each time, the liquid amount is corrected by the above equation (1) or (3). It is possible to that way,
There is no need for a high-precision pump that was required in the past,
On the contrary, the overall measurement accuracy is improved.

The detection of the dispensed amount is carried out by directly measuring the dispensed amount from the sample probe or by calculating the displacement amount of the pump. For example, in the case of a commonly used syringe type pump (Fig. 3), if the inner diameter of the syringe or the outer shape of the plunger is known, it is possible to calculate the dispensed amount by measuring the moving distance. Become.

When accurate dispensing is obtained by the above means, the data correcting means corrects the absorbance data to an appropriate data value based on the above equation (1) or equation (3). Therefore, it is possible to obtain highly accurate inspection data even if the dispensed amount of the sample or the like changes to some extent.

An embodiment of the automatic analyzer of the present invention will be described below with reference to the drawings.

FIG. 1 is a functional block diagram showing the basic configuration of the apparatus used in this embodiment.

When a measurement item or the like is input and set from the input system 1, the sampling control means 21 of the control system 2 operates a sampling pump or the like of the drive system 3 to dispense a sample or a reagent into the reaction tube 4. The actuator of the sampling pump 31 that constitutes the drive system 3 includes the stroke pump 3
The stroke pump 310 is equipped with a syringe 32. By driving the stroke pump 310, the plunger in the syringe operates and sucks / discharges the sample or the like. The movement distance (shift amount) of this plunger base is detected by the laser displacement meter (sensor 5). ..

As shown in FIGS. 2 and 3, when the operating voltage is supplied from the control system 2 to the stroke pump 310 of the sampling pump 31 of the drive system 3, the stroke pump 3
10 is driven, and the plunger 321 of the syringe 32 is stroked. The stroke of the plunger 321 is transmitted to the pressure transmitting portion 33, whereby the pipette probe 3
4, sucking the sample liquid or the like into the syringe 32,
The aspirated sample liquid or the like is dispensed into the reaction tube 4.

On the other hand, the monitor voltage obtained by the sensor 5 for monitoring the displacement amount of the plunger base is the control system 2
Is sent to the operation amount monitoring means 22. This allows
The movement amount monitoring means 22 monitors a change or the like due to the operating voltage, so that the movement amount of the sampling pump 31 can be accurately determined.

In the dispensing amount calculating means 23 of the control system 2, the moving distance (a0-a1) of the plunger 321 is calculated from the operation amount of the sampling pump 31, and the dispensing distance is calculated by this and the known inner radius r of the syringe 32. Quantity πr ² × (a0-a1)
To calculate. On the other hand, the progress of the chemical reaction between the sample and the reagent is measured by the reaction measuring system 6 as the absorbance and the data as the measurement result is collected by the data collecting means 24 of the control system 2.

The data correction means 23 corrects the absorbance to an appropriate value according to the change in the dispensed amount calculated by the dispensed amount calculating means 23 based on the equation (1) or the equation (3). A simple illustration of this correction is shown in FIG.
When the dispensed amount set by the command in the input system 1 is V1, but the dispensed amount calculated is V2, the absorbance A1 is corrected to A2. Then, the corrected data is output and displayed on the display system 7 as a measurement result.

In the above embodiment, the stroke pump is used as the sampling pump 31 of the drive system 3 and the laser displacement meter (sensor 5) is used as the monitor in order to obtain the dispensing amount information of the sample or the like, but the invention is not limited to this. is not. Another example will be described below.

As an example thereof, laser light is scanned in the longitudinal direction of the syringe 32, or the moving distance (a0-a1) of the plunger 321 is obtained by parallel light, and the dispensing amount is calculated in the same manner as in the above embodiment. You can also

As a method for directly measuring the amount of the sample or the reagent discharged from the tip of the pipette probe 34, a pulse drive source applying a piezoelectric element or the like is used to dispense from the tip of the pipette probe 34. The solution is ejected in a pulse shape as small droplets. Then, the dispensed amount can be calculated by counting the number of ejected droplets using laser light, determining the volume of the droplet based on the diameter of the droplet, and integrating these.

[0026]

According to the automatic analyzer of the present invention, the dispensing amount of the pipette probe can be grasped and the measurement data can be corrected in accordance with the change in the dispensing amount. Therefore, it is possible to increase the reliability of the measured value without pursuing the mechanical accuracy of each component of the device, and to simplify the mechanical structure of the device while maintaining the data value as the measurement result with high accuracy. And the manufacturing cost of the device itself can be reduced.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a basic configuration of an apparatus used in an embodiment of the present invention.

FIG. 2 is a block diagram showing a drive system and the like of the same embodiment.

FIG. 3 is a diagram showing an operational relationship between a drive system and a pipette probe of the same embodiment.

FIG. 4 is a diagram showing the relationship between the absorbance and the dispensed amount of a sample or the like.

[Explanation of symbols] 1 input system 2 control system 3 drive system 5 sensor 6 reaction measurement system 22 operation amount monitor means 23 dispensing amount calculation means 24 data collection means 25 data correction means

Claims (1)

[Claims] 1. An automatic analyzer for measuring a chemical reaction by aspirating a predetermined amount of a reagent or sample for which a command has been set in advance into a pipette probe by operating a sampling pump, and dispensing these solutions into a reaction tube. A sensor that detects the operation of the sampling pump, an operation amount monitoring unit that monitors the operation amount of the sampling pump based on the output signal from the sensor, and a dispensing amount calculation unit that calculates the dispensing amount from the operation amount. An automatic analyzer comprising: a data correction unit that corrects the measured data according to the dispensed amount.