JPH09297122A - Analyzing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a substance to be measured with high precision and quantitatively analyze it without replacing a liquid feed pump even when the performance of the pump is lowered by providing a pump control means, and controlling the rotating speed of the pump so that the flow rate of a liquid to be measured flowing into a flow type measuring cell becomes a preset flow rate. SOLUTION: A peristaltic pump 13 as a liquid feed pump is connected to the outlet part of a flow type measuring cell 1 through a sample discharge pipe 12. The peristaltic pump 13 has a liquid feed roller 13b for feeding the liquid within a liquid feed tube 13a. A controller 16 as the peristaltic pump control means is connected to a motor 14 for driving the liquid feed roller 13b through a motor driving circuit 15. The controller 16 has a CPU 16a, and a memory part 16b for storing a plurality of rotating speed set data for setting the rotating speed of the pump 13. Since the pump 13 is driven on the basis of the rotating speed set data in measurement of ion concentration, quantitative analysis can be precisely performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analyzer used for component analysis of sample liquids such as serum and urine,
In particular, it relates to an analyzer for quantitatively analyzing a substance to be measured contained in a sample liquid.

[0002]

2. Description of the Related Art In general, sample liquids such as serum and urine contain Na ⁺ ,
Electrolyte components that are substances to be measured, such as K ⁺ and Cl ⁻ , are contained, and devices for quantitatively analyzing these electrolyte components are disclosed in, for example, Japanese Patent Application Laid-Open No. 61-51556 and Japanese Patent Application Laid-Open No. 1-282459. The electrolyte component analyzers described are known.

The electrolyte component analyzer disclosed in Japanese Patent Laid-Open No. 61-51556 is equipped with a container for diluting a sample liquid such as serum with a diluting liquid such as water (hereinafter referred to as a diluting container). The sample liquid diluted in this dilution container is sucked into the flow type measuring cell through the sample liquid introducing pipe, and the potential difference between the ion selective electrode and the reference electrode provided in this flow type measuring cell is measured. Based on this, quantitative analysis of electrolyte components such as Na ⁺ is performed.

On the other hand, the electrolyte component analyzer described in Japanese Patent Application Laid-Open No. 1-282459 sucks the sample liquid contained in the sample container into the flow type measuring cell through the sample liquid introducing pipe, and performs the flow type measurement. Based on the potential difference between the ion selective electrode and the reference electrode provided in the cell, Na
It is designed to quantitatively analyze electrolyte components such as ⁺ .

By the way, in the above-mentioned electrolyte component analyzer, a syringe pump (piston pump) is used as a liquid feed pump for feeding the sample liquid to the flow type measuring cell. For this reason, when sending a large amount of sample liquid to the flow-type measurement cell, it is necessary to use a syringe pump with a large suction capacity or use a plurality of small syringe pumps, thereby increasing the size of the device. There was a problem of inviting. Also, instead of using a large syringe pump, a method of sending a sample solution to a flow type measurement cell using a small syringe pump can be considered, but such a method sends a sample solution to the flow type measurement cell. There was a problem that it took too long to finish.

Further, in the above-mentioned electrolyte component analyzer,
If the piston or cylinder of the syringe pump wears,
These pump parts need to be replaced periodically because the syringe pump's ability to deliver liquids declines. However, since the pump parts of a syringe pump are generally expensive,
There is also a problem that replacement of pump parts requires a large amount of money.

Therefore, an electrolyte component analyzer using a peristaltic pump (roller pump) as a liquid feed pump for feeding a sample liquid to a flow type measuring cell is disclosed in JP-A-2-6644.
No. 1 discloses this. According to such an electrolyte component analyzer, the peristaltic pump is provided with a liquid feed tube made of an elastic material, and the liquid feed tube is handled by a liquid feed roller to feed the liquid in the liquid feed tube in a predetermined direction. Therefore, a large amount of sample liquid can be sent to the flow type measurement cell without causing an increase in the size of the device. Further, unlike the syringe pump, it is not necessary to regularly replace the pump parts, so that the cost required for maintenance and inspection of the liquid delivery pump can be reduced.

[0008]

However, in the above-described electrolyte component analyzer, if the usage period is long,
The liquid feeding tube gradually deteriorates, and in particular, the elasticity of the liquid feeding tube in the peristaltic pump decreases, so that the liquid feeding ability of the peristaltic pump also decreases. When the liquid delivery capacity of the peristaltic pump is lowered, it becomes difficult to deliver the sample liquid to the flow type measuring cell within a predetermined time, and the sample liquid may remain in the sample liquid introducing pipe. Therefore, in the above-described electrolyte component analyzer, when the next sample liquid is sent to the flow-type measurement cell and the electrolyte component is quantitatively analyzed, the sample liquid remaining in the sample liquid introduction tube attempts to be measured. There is a possibility that it may be mixed in the sample solution and the analysis accuracy may be reduced.

In addition, since the normal liquid transfer tubes used in peristaltic pumps and the like have variations in accuracy such as diameter, hardness (elasticity), etc., all of them are replaced with new ones. Then, due to the respective variations, the amount of liquid to be delivered became faster or slower. In particular, if the amount of liquid to be sent is too fast, the sample liquid will be lost from the flow-type measuring cell during the measurement period, and erroneous measurements will be made. Since there is a risk that it will not be able to measure accurately due to inhalation of etc., it had to be replaced.

The present invention has been made in view of the above points, and an object thereof is to replace or replace a pump or the like even if the liquid-sending capacity of a liquid-sending pump for sending a liquid to be measured to a flow type measuring cell is lowered. It is an object of the present invention to provide an analyzer capable of quantitatively analyzing a substance to be measured (for example, an electrolyte component) in a liquid to be measured with high accuracy while maintaining high accuracy.

[0011]

The invention according to claim 1 is
In order to solve the above-mentioned problems, a container that stores a predetermined amount of the liquid to be measured, a flow-type measurement cell that quantitatively analyzes the liquid to be measured in the container through a predetermined pipeline, and from the container A liquid feed pump that feeds the liquid to be measured to the flow type measurement cell, and rotation of the liquid feed pump so that the flow rate of the liquid to be measured flowing into the flow type measurement cell becomes a preset flow rate. And a pump control means for controlling the number.

According to a second aspect of the invention, in the invention according to the first aspect, the pump control means sequentially feeds a predetermined amount of a diluent and a standard solution to the flow type measurement cell to perform the flow type measurement. Characterized in that the liquid feeding ability of the liquid feeding pump is detected based on a potential change of an ion selective electrode provided in the cell, and the rotation speed of the liquid feeding pump is controlled based on the detection result. Is.

According to a third aspect of the present invention, in the first aspect of the present invention, the pump control means feeds a predetermined amount of liquid to the flow type measuring cell to determine the liquid feeding capacity of the liquid feeding pump. It is characterized in that detection is performed based on a signal from a liquid level detection means provided in the container, and the rotation speed of the liquid feed pump is controlled based on the detection result.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of an analyzer according to the first embodiment of the present invention. In the figure, 1 is a flow type measuring cell, and inside the flow type measuring cell 1, for example, a Na ion selective electrode 2, a K ion selective electrode 3, a Cl ion selective electrode 4 and a reference electrode 5 are provided. It is provided.

The Na ion-selective electrode 2, the K ion-selective electrode 3, the Cl ion-selective electrode 4 and the reference electrode 5 are connected to signal input terminals of the voltage conversion circuit 7 via signal lines 6a, 6b, 6c and 6d (see FIG. (Not shown), these Na ion selective electrode 2 and K ion selective electrode 3
The potential difference generated between the Cl ion selective electrode 4 and the reference electrode 5 is output from the voltage conversion circuit 7 as a voltage signal. The voltage signal output from the voltage conversion circuit 7 is converted into a digital signal by the A / D converter 8 and then supplied to the concentration calculator 9 for calculating the ion concentration of Na ⁺ or the like. .

One end of a sample liquid introducing tube 10 is connected to the inlet of the flow type measuring cell 1. The other end of the sample liquid introducing pipe 10 is connected to the bottom of the diluting container 11, and the sample liquid diluted in the diluting container 11 is the sample liquid introducing pipe 10.
To flow into the flow type measuring cell 1.

On the other hand, at the outlet of the flow type measuring cell 1,
A peristaltic pump 13 as a liquid feed pump is connected via a sample drainage pipe 12. This peristaltic pump 1
3 includes a liquid feeding tube 13a made of an elastic material, and a liquid feeding roller 13b that handles the liquid feeding tube 13a and feeds the liquid in the tube in a predetermined direction.
A controller 16 as a peristaltic pump control means is connected to a motor 14 that drives 3b via a motor drive circuit 15. The sample liquid discharged from the peristaltic pump 13 is introduced into a drain tank (not shown).

The controller 16 is provided with a CPU (central processing unit) 16a. In the CPU 16a, for example, the potential difference generated between the Na ion selective electrode 2 and the reference electrode 5 is a voltage conversion circuit 7 and an A / D. It is adapted to be supplied via the converter 8.

The controller 16 is a storage device 16b.
As shown in FIG. 2, the storage device 16b includes a plurality of rotation speed setting data D1 (normal rotation speed) and D2 (10% of the normal rotation speed) for setting the rotation speed of the peristaltic pump 13. Fast rotation speed), D3 (20 times faster than normal rotation speed)
% Faster speed), D4 (30% faster than normal speed), D5 (10% slower than normal speed), D6
(20% slower than normal speed) and D7 (30% slower than normal speed) are stored,
Time data T1 (for example, 10 seconds), T2 (for example, 12 seconds)
Seconds), T3 (eg 14 seconds), T4 (eg 16 seconds), T5
(Eg 8 seconds), T6 (eg 6 seconds), T7 (eg 4 seconds)
Second) is the rotation speed setting data D1, D2, D3, D4, D
5, D6 and D7 are stored.

Further, in FIG. 1, reference numeral 17 is a sample liquid dispenser for dispensing the sample liquid into the diluting container 11, 18 is a diluting liquid dispenser for dispensing the diluting liquid into the diluting container 11, and 19 is a Dilution container 1
1 is a standard solution dispenser that dispenses a standard solution into the inside of the container 1. Each of these dispensers 17, 18 and 19 is connected to a syringe pump (not shown) controlled by the controller 16 and appropriately dispensed in a fixed amount. It Further, 20 is a stirrer for stirring the inside of the dilution container 11, 21 is a reference liquid storage tank, 22 is a reference liquid supply pipe for supplying the reference liquid stored in the reference liquid storage tank 21 to the flow type measurement cell 1, 23 Is an input / output device including an input unit for setting and supporting analysis items and operation contents, and an output unit for displaying operation contents and analysis results on a screen or the like.

FIG. 3 is a flow chart for explaining the control sequence of the CPU 16a, and the operation of this embodiment will be described below with reference to FIG. First, when a switch (not shown) is pressed by the input / output device 23, C
A diluted liquid dispensing signal is sent from the PU 16a to the diluted liquid dispenser 18 (step ST1). When a diluting liquid dispensing signal is sent from the CPU 16a, the diluting liquid dispenser 18 is actuated to dispense a predetermined amount of diluting liquid into the diluting container 11.

When a predetermined time has elapsed after the diluted liquid dispensing signal was sent to the diluted liquid dispenser 18, a pump drive signal is sent from the CPU 16a to the motor drive circuit 15 (step ST2). Then, when a pump drive signal is sent from the CPU 16a, the liquid feed roller 13 of the peristaltic pump 13 is sent.
b is rotatably driven by a motor 14, whereby the diluted liquid dispensed into the diluting container 11 flows through the sample liquid introducing pipe 10, the flow type measuring cell 1 and the sample drain pipe 12 and a drain tank (not shown). Is discharged to. At this time, it is preferable that the diluting liquid is sent so that the diluting liquid in the diluting container 11 is completely exhausted or the diluting amount is reduced.

When the diluted solution dispensed into the diluting container 11 flows through the flow type measuring cell 1 and is discharged to a drain tank (not shown), the peristaltic pump 13 is driven by a pump stop signal sent from the CPU 16a. Stops (step ST3). Then, when the driving of the peristaltic pump 13 is stopped, the standard solution dispenser 19 is operated by the standard solution dispensing signal sent from the CPU 16a, whereby a predetermined amount of standard solution is dispensed into the dilution container 11 ( Step ST
4).

When a predetermined time elapses after the standard liquid pipetting signal is sent to the standard liquid pipetting device 19, the peristaltic pump 13 is set at a preset rotation speed (for example, in the storage device 16b) by the pump drive signal sent from the CPU 16a. The standard solution, which is driven by the stored D1 rotation number) (step ST5), is dispensed into the diluting container 11 at a flow rate corresponding to the pumping capacity of the pump at that time. It is introduced into the flow type measuring cell 1 through the flow of 10. Then, when the standard solution dispensed in the diluting container 11 is introduced into the flow type measuring cell 1, the standard solution contains an electrolyte component such as Na ^{+, and} therefore, for example, the Na ion selective electrode 2 And the potential difference between the reference electrode 5 and the reference electrode 5 suddenly changes.

At this time, the CPU 16a suspends the driving of the peristaltic pump 13 if necessary, and sends a pump drive signal in step ST5, and then the potential difference between the Na ion selective electrode 2 and the reference electrode 5 changes rapidly. The time T until it is measured is measured (step ST6), and this time T is collated with a plurality of time data T1 to T7 stored in the storage device 16b (steps ST7 to ST13).
Then, the time data T1 to T1 stored in the storage device 16b
If there is no time data equal to the measurement time T in T7, the CPU 16a displays an error on the input / output device 23 (step ST20), and therefore the replacement time of the liquid supply tube 13a is indicated. If the time data T1 to T7 stored in the storage device 16b includes time data having the same value as the measured time T, the CPU 16a selects the rotation speed setting data (for example, D2) corresponding to the time data. (Steps ST14 to ST21).

In this way, when the standard solution and the sample solution thereafter are sent to the flow type measuring cell 1 to measure the ion concentration of Na ⁺ etc., the peristaltic pump 13 is set based on the selected rotation speed setting data. To drive. The selected rotation speed setting data is preferably displayed on the input / output device 23.

Therefore, in the first embodiment of the present invention, the peristaltic pump 13 is selected when the sample solution diluted in the dilution container 11 is introduced into the flow type measuring cell 1 to measure the ion concentration of Na ⁺ or the like. Since it is driven based on the set rotation speed setting data, even if the peristaltic pump 1
Even if the liquid feeding tube 13a of No. 3 is deteriorated, the sample liquid can be fed to the flow type measuring cell 1 without being left in the sample liquid introducing tube 10, and thereby the electrolyte component in the sample liquid can be increased. Quantitative analysis can be performed with high accuracy.

In particular, in the above-described first embodiment, the control is performed by sending the standard solution after sending the diluting solution.
Since the original function (in the first embodiment, the potential difference between the ion-selective electrode and the reference electrode is observed) is used without adding a special configuration, there is an advantage that the configuration is simple. is there.

If the flow velocity is simply measured, a small amount of the diluted solution and / or the standard solution may be dispensed. Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 4 is a schematic diagram of an analyzer according to the second embodiment of the present invention. In the figure, reference numeral 24 is a liquid level detector as liquid level detecting means for detecting the liquid level in the diluting container 11 with a pair of electrodes. The signal output from the liquid level detector 24 is a peristaltic pump control means. Is supplied to the controller 25.

The controller 25 includes a CPU 25a and a storage device 25b connected to the CPU 25a via a data bus. The storage device 25b includes the storage device 25b shown in FIG.
As shown in FIG. 4, a plurality of rotation speed setting data D11 (normal rotation speed) for setting the rotation speed of the peristaltic pump 13, D1
2 (10% faster than normal speed), D13 (20% faster than normal speed), D14 (30% faster than normal speed), D15 (10 faster than normal speed) %
Slow speed), D16 (20% slower than normal speed), D17 (30% slower than normal speed) are stored, and a plurality of time data T11 (for example, 5 seconds), T12 (eg 6 seconds), T13 (eg 7
Seconds), T14 (eg 8 seconds), T15 (eg 4 seconds),
T16 (for example, 3 seconds) and T17 (for example, 2 seconds) are rotation speed setting data D11, D12, D13, D14, D15,
It is stored corresponding to D16 and D17.

In such a structure, in the second embodiment of the present invention, for example, when a switch (not shown) is pushed down, the diluted liquid dispensing signal from the CPU 25a activates the diluted liquid dispenser 18, whereby the diluted liquid is dispensed. The time when the liquid level detector 24 detects the rising liquid level from the preset amount (dilution liquid injection start time (t1 in FIG. 6)) in the container 11 (FIG. 6).
The amount corresponding to the middle t3) and the amount of the diluting liquid from the time t3 to the time point when the injection of the diluting liquid is performed for a certain time (t2 in FIG. 6) are dispensed. At that time, as shown in FIG. 6, the output of the liquid level detector 24 is switched from OFF to ON.

Next, the peristaltic pump 13 is driven at a preset number of revolutions (for example, the number of revolutions of D1 stored in the storage device 25b) by the pump drive signal sent from the CPU 25a. The diluted liquid thus dispensed is introduced into the flow type measuring cell 1 through the sample liquid introducing pipe 10.

At this time, the CPU 25a uses the liquid level detector 24.
The output signal of the liquid level detector 24 becomes O from time t4 when the pump drive signal is sent out as shown in FIG.
The time T until the time point when FF is reached (t5 in FIG. 6) is measured, and this time T is collated with the time data T11 to T17 stored in the storage device 25b. Then, from these time data T11 to T17, the rotation speed setting data (for example, D12) corresponding to the time data (for example, T12) closest to the measurement time T is selected, and the subsequent liquid feeding is performed.

In this way, when the sample solution is sent to the flow type measuring cell 1 to measure the ion concentration of Na ⁺ etc., the peristaltic pump 13 is driven based on the selected rotation speed setting data.

Therefore, in the second embodiment of the present invention, since the peristaltic pump 13 is driven based on the selected rotation speed setting data when the sample liquid is sent to the flow type measuring cell 1, the peristaltic pump 13 is sent. Even if the liquid tube 13a is deteriorated, the sample liquid can be sent to the flow-type measurement cell 1 without being left in the sample liquid introducing tube 10, whereby the electrolyte component in the sample liquid can be quantitatively analyzed with high accuracy. can do.

Further, in the above-described second embodiment, the liquid level detector 24 functions as an abnormality detection sensor even in the normal measurement operation, and is not a special part for measuring the flow rate, so that the apparatus becomes particularly complicated. It does not increase the cost.

Further, in the above-described second embodiment, since the rotation speed of the peristaltic pump 13 can be controlled by measuring only the diluting solution, as in the above-described first embodiment,
Other than the flow measurement cell using the ion-selective electrode, for example, the flow measurement cell for colorimetric measurement of the reaction solution housed in the reaction container can be used.

In the second embodiment described above, the liquid level detector 24 that is generally provided to prevent the overflow of the sample liquid or the like dispensed in the dilution container 11 is used. As can be seen by comparison with the first embodiment,
In addition to the original function (function to detect the liquid level of sample liquid etc.),
Since the liquid level of the diluted liquid dispensed in the diluting container 11 is detected and the liquid sending time is measured based on the detection signal,
Although the configuration is more complicated than that of the first embodiment, unlike the first embodiment, it is not necessary to send two kinds of liquids having a potential difference to the flow type measuring cell 1, so that dispensing and liquid sending are possible. Not only can you reduce the number of times, but you can choose the type of liquid,
It can also be applied to the rotation speed control of a peristaltic pump of an analyzer using a flow type measuring cell for colorimetric measurement of a reaction solution other than the flow type measuring cell using an ion selective electrode.

Further, since the measurement time T is determined at the time (t5) when the liquid amount that can be determined only during the operating time of the dispenser (from time t3 to t2) is obtained, one dispenser is used for each dispenser. When driven by the dispensing pump, it is preferable that one or both of the dispensing pump and the liquid-sending pump have a reduced liquid-sending ability because a constant liquid-sending state can be maintained.

In the above-described first and second embodiments, the analyzing apparatus having a structure in which the sample solution diluted in the diluting container 11 is sent to the flow type measuring cell 1 through the sample solution introducing pipe 10 has been described. However, the present invention is not limited to the above-described embodiment, and is disclosed in, for example, Japanese Patent Laid-Open No. 61-5155.
It can also be applied to the analyzers described in Japanese Patent Laid-Open No. 6 and Japanese Patent Laid-Open No. 1-282459.

Further, the liquid level detector described above is not limited to that of the second embodiment, and for example, a device for optically detecting the liquid level can be effectively used. Further, in the flow velocity measurement in the first embodiment, it is not always necessary to obtain the potential difference, and it may be obtained from the potential change by only any one kind of electrode, preferably the ion selective electrode.

[0043]

As described above, according to the present invention,
It is possible to provide an analyzer capable of highly accurately quantitatively analyzing a substance to be measured in a liquid to be measured even if the liquid feeding capacity of a liquid feed pump that feeds the liquid to be measured into a flow type measurement cell is lowered.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an analyzer according to a first embodiment of the present invention.

FIG. 2 is an exemplary view for explaining data stored in a storage device of the analysis device according to the embodiment.

FIG. 3 is a flowchart for explaining the operation of the analysis device according to the same embodiment.

FIG. 4 is a schematic diagram of an analyzer according to a second embodiment of the present invention.

FIG. 5 is an exemplary view for explaining data stored in the storage device of the analysis device according to the embodiment.

FIG. 6 is a signal waveform diagram for explaining the operation of the analyzer according to the same embodiment.

[Explanation of symbols]

 1 ... Flow-type measuring cell 2 ... Na ion selective electrode 3 ... K ion selective electrode 4 ... Cl ion selective electrode 5 ... Reference electrode 10 ... Sample liquid introduction pipe 11 ... Dilution container 12 ... Sample drain pipe 13 ... Perister pump 15, 25 ... Controller 15a, 25a ... CPU 15b, 25b ... Storage device 24 ... Liquid level detector

Claims (3)

[Claims] 1. A container for containing a predetermined amount of liquid to be measured, a flow type measuring cell for quantitatively analyzing the liquid to be measured in the container through a predetermined pipe line, and the flow type measurement from the container. A liquid feed pump that feeds the liquid to be measured to a cell, and the rotation speed of the liquid feed pump is controlled so that the flow rate of the liquid to be measured flowing into the flow-type measurement cell becomes a preset flow rate. An analyzer comprising a pump control means. 2. The pump control means sequentially feeds a predetermined amount of a diluting solution and a standard solution to the flow-type measuring cell to change the potential of an ion-selective electrode provided in the flow-type measuring cell. 2. The analyzer according to claim 1, wherein the liquid feeding capacity of the liquid feeding pump is detected based on the detection result, and the rotation speed of the liquid feeding pump is controlled based on the detection result. 3. The pump control means feeds a predetermined amount of liquid to the flow-type measurement cell to indicate the liquid feed capacity of the liquid feed pump from a liquid level detection means provided in the container. 2. The analyzer according to claim 1, wherein the number of rotations of the liquid feed pump is controlled based on the detection result.