JPS6394149A - System for measuring concentration of electrolyte - Google Patents

Abstract

PURPOSE:To permit continuation of a measurement operation without degrading accuracy by detecting the volume of a liquid to be measured failing to attain a prescribed value and discharging a soln. for calibration into a reaction tube for the liquid to be measured at the time of sucking the liquid to be measured from a supply vessel. CONSTITUTION:A signal for the abnormality in the volume of suction is transmitted from a pressure sensor 23 to a CPU 14 when the volume of the sample liquid to be sucked from the supply vessel into a sample liquid discharging nozzle 6 does not attain the prescribed value in a suction position (b). The CPU 14 stops the movement of the nozzle 6 from the position (b) to a discharge position (c) and moves the reaction tube 3 for the sample liquid slightly to the position of a calibrating liquid discharging nozzle 5 by a conveyor belt 4, where the calibrating liquid of the nozzle 5 is discharged into the reaction tube 3 and the measurement operation is continued. The electromotive forces of the calibrating liquid in the reaction tube 2 for the calibrating liquid and the calibrating liquid in the reaction tube 3 are, consequently, measured continuously in a measuring part 8a of an ion electrode 8. However, a level difference does not exist intrinsically in the measured values between the two and, therefore, the measurement operation is continued without aversely affecting the measurement results of the ensuing other reaction tubes even if such measurement operation is intervened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement of an electrolyte concentration measurement system in an automatic biochemical analyzer used, for example, in the field of medical testing.

(Prior Art) In medical diagnosis, various tests are performed using automatic analyzers, and measurements of electrolyte concentrations in living organisms, for example, Na'''-3 contained in body fluids such as serum and urine.
- When measuring the ionic activity of each ion such as CI-, a measurement method using an ion-selective electrode (hereinafter simply referred to as an ion electrode) is generally used.

In this case, since the ion electrode has the property that its response deteriorates when the concentration change of the liquid to be measured (hereinafter referred to as sample liquid) is large, it is necessary to use a high-precision electrode that measures each of the ions mentioned above. In the case of analytical equipment, measures have been taken to prevent "variations" in sample liquid concentration from having a negative effect on the concentration of the sample liquid. , simply referred to as a calibration solution), and measure the calibration solution each time a sample liquid is measured.

(Problems to be Solved by the Invention) On the other hand, in this type of measurement work, in order to effectively utilize a small amount of sample liquid, it is common practice to dilute the sample liquid to a predetermined ratio before measurement. In this case, if there is a shortage of sample liquid or a phenomenon of empty suction from the supply container (such as when the nozzle is clogged with fibrin), it becomes impossible to obtain a predetermined dilution ratio, leading to deterioration in the responsiveness of the ion electrode. And when things like this come to ffl,
This causes a problem in that not only the sample liquid with an abnormal dilution ratio but also the measurement results of subsequent sample liquids are seriously affected.

The present invention was made in view of this situation, and even if an abnormality occurs in the amount of sample liquid to be subjected to measurement,
It is an object of the present invention to provide a novel electrolyte concentration measurement system that allows measurement operations to be continued without deteriorating accuracy.

[Structure of the Invention] (Means for Solving the Problems) The structure of the present invention for achieving this object is to discharge a calibration solution and a liquid to be measured into each reaction tube, and to In an electrolyte concentration measurement system that measures electrolyte concentration by sequentially introducing both solutions into an ion-selective electrode site, when the sample liquid is drawn from its supply container, the amount of sample liquid to be subjected to measurement is The purpose is to detect that the predetermined value has not been reached and to discharge the calibration solution into the reaction tube for the liquid to be measured.

(Function) The function of the present invention based on this configuration is that when an abnormality occurs in the amount of sample liquid to be subjected to measurement, the discharging of the sample liquid that has caused the right rotation ratio abnormality is stopped, and instead, a predetermined magnification is By discharging the diluted calibration solution into the reaction tube for the sample solution, the second constant operation is continued.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. The drawing is a schematic configuration diagram of an automatic analyzer to which the electrolyte concentration measurement system according to the present invention is applied. These two reaction tubes 2 and 3 are arranged in a pair in front and behind so that the reaction tube 2 for calibration solution is located in front of the reaction tube 2 for the calibration solution in the direction of movement. Configure. 4 is a conveyance line that holds a plurality of pairs of reaction frameworks 2 and 3 and conveys them inside the thermostatic chamber 1, and by means of an appropriate conveyance mechanism, a predetermined endless trajectory path inside the thermostatic chamber 1 is carried in the direction of the arrow (A) shown in the figure. The moving distance (moving time) is the temperature of the calibration solution and sample solution in the pair of reaction frames 2 and 3, or approximately the same temperature as the fluid in the thermostatic chamber 1. is set based on the time until

Reference numeral 5 denotes a calibration liquid discharge nozzle provided at a predetermined location around the constant temperature J61, and discharges a calibration liquid diluted in advance to a predetermined ratio into the calibration liquid reaction tube 2. Reference numeral 6 denotes a sample liquid discharge nozzle installed adjacent to the calibration liquid discharge nozzle 5, which sucks the sample liquid to be subjected to measurement from its supply container (not shown); tube 3
It is constructed by appropriate means so as to be able to reciprocate between the order (c) and the order (c) from which it is discharged. Reference numeral 7 denotes a diluent discharge nozzle arranged in parallel with the discharge position (c) of the sample liquid discharge nozzle 6, and during normal measurement operations, both of these nozzles 6
and 7, the sample liquid and diluent are discharged to the sample liquid reaction tube 3 simultaneously or sequentially.

Reference numeral 8 denotes an ion electrode having an appropriate configuration, which has a measuring section 8a inside thereof, and a suction pipe 8b at its lower end for sequentially sucking a calibration solution and a sample liquid into the measuring section 8a. . The ion electrode 8 is held in the electrode holding part 9 at the time of measurement, and at least the suction tube 8b
The connecting reaction tubes 2 and 3 are connected by an electrode lifting mechanism (not shown).
It is constructed with a moat that can be moved up and down. In addition, this suction pipe 8b
can also be configured to be able to move on the movement trajectory of the transport line 4 by the distance between the reaction tubes 2 and 3 arranged in front and behind.

10 is a solenoid valve that communicates with the ion electrode 8 through a suitable conduit; 11 is a suction pump that communicates with the ion electrode 8 and the outside of the device through the solenoid valve 10; and 12 is connected to the ion electrode 8. 1 is a preamplifier; 13 is an A/D converter; 14 is a CPU that controls the entire automatic analyzer;
5 is a pipe for communicating the electrode holding part 9 with both end regions of the thermostatic oven l, and 16 is a circulation pump connected to this pipe 15 to force the fluid in the thermostatic oven l to the electrode holding part 9. The fluid in the constant temperature bath l and the fluid in the electrode holding part 9 are kept at the same temperature at all times.

Note that the flow path from the inside of the constant temperature bath 1 to the inside of the electrode holding part 9 is filled with a fluid having a large heat capacity, such as water.

21 is a supply pump connected to the sample liquid discharge nozzle 6 through an appropriate supply pipe 22; 23 is a pressure sensor installed at an appropriate location around the supply pipe 22; the sample liquid to be measured is transferred to the supply container ( When the sample liquid is sucked into the sample liquid discharge nozzle 6 from the sample liquid (not shown), the suction amount is detected based on the liquid pressure change value per unit time in the supply pipe 22, and the detection signal is transmitted to the control CPU. It is configured as follows.

Next, a method for measuring electrolyte concentration using the automatic analyzer having this configuration will be explained.

[In case of normal measurement] At the start of the measurement operation, the set of reaction skeletons 2 and 3 held in the transport line 4 are positioned at the position of the calibration liquid discharge nozzle 5 and the discharge position of the sample liquid discharge nozzle 6, respectively. The sample liquid discharge nozzle 6 itself faces the supply container (not shown) at the suction position (b).

In this state, first, a calibration solution that has been diluted in advance to a predetermined ratio according to the purpose of measurement is discharged from the discharge nozzle 5 into the reaction tube 2 for calibration solution. Next, at the suction position 21 (b), an amount of sample liquid to be subjected to measurement is sucked into the sample liquid discharge nozzle 6 from the supply container. When the pressure sensor 23 detects that the amount of sample liquid sucked has reached a predetermined value, the sample liquid discharge nozzle 6 moves from its suction position (b) to its discharge position (
Then, the sample liquid is discharged into the sample liquid reaction tube 3. Thereafter, the diluent is discharged from the diluent discharge nozzle 7 into the reaction tube 3 sequentially or in the same number of times to dilute the sample liquid to a predetermined ratio.

The set of reaction skeletons 2 and 3 that have undergone such a discharge operation move in the direction of arrow (a) along a predetermined path within the thermostatic chamber 1 over a predetermined period of time as the transport line 4 moves. When the calibration solution reaction tube 2 reaches the position of the suction tube 8b of the ion electrode 8, it stops. At this time, the suction tube 8b of the ion electrode 8 is lowered into the calibration liquid reaction tube 2 by the operation of the electrode lifting mechanism (not shown), and the electromagnetic valve 10 and the suction pump 11 are almost simultaneously operated in a predetermined suction operation. Do it,
The calibration solution in the reaction tube 2 is sucked into the measurement part 8a of the ion electrode 8. Then, this aspirated calibration solution is transferred to the measuring section 8.
At step a, the electromotive force is measured by a method known per se. The measured calibration liquid is once sucked into the suction pump 11, and after the solenoid valve 10 is switched to the discharge state, it is then discharged out of the apparatus by the pushing operation of the suction pump 11.

After the process of measuring the electromotive force related to the calibration solution is completed, the transfer line 4 is moved slightly (or the suction pipe 8b is moved by the distance described above), and the sample liquid reaction tube 3 is connected to the suction of the ion electrode 8. Set at the position of tube 8b. Then, by the same operation as in the case of the above-mentioned calibration solution, the measuring part 8 of the ion electrode 8
The electromotive force of the sample liquid sucked into the measuring section 8a is measured. That is, the suction pipe 8b descends again to suck in the sample liquid in the sample liquid reaction tube 3, and after measuring a predetermined electromotive force, the measured sample liquid is discharged to the outside of the apparatus.

In this case, the passage paths of the sample liquid and the calibration liquid from the respective discharge operations to the measurement part 8a of the ion electrode 8 are the same, so measurement errors caused by differences in the passage paths as in the conventional case are avoided. For example, it is difficult to cause a degree measurement error due to a difference in the degree of concentration of both liquids due to evaporation. Further, the calibration liquid and sample liquid in the measurement section 8a will be held in the electrode holding section 9 throughout the measurement process, but the fluid in this electrode holding section 9 will be kept in the pipe 15. and li'l
Since it is in communication with the fluid in the constant temperature bath l via the ring pump 16, its temperature is maintained approximately the same as the temperature of the fluid in the constant temperature bath l. Therefore, during the measurement process of the calibration liquid and the sample liquid, almost no measurement error occurs due to a difference in temperature as in the conventional method.

Now, the measurement outputs related to the calibration liquid and the sample liquid measured in such an equivalent temperature atmosphere are respectively transmitted to the CPU 14 via the preamplifier 12 and the A/D converter 13, and in the CPU 14, the measurement outputs are transmitted to the sample liquid. After performing a predetermined calculation process of subtracting the electromotive force of the calibration solution from the electromotive force measurement value, the content of the target ion is calculated from the actual electromotive force value, and it is calculated using an appropriate method (not shown). Output to an output device, such as a printer or cathode ray tube,
Displays electrolyte concentration measurement results.

On the other hand, the measured sample liquid is either discharged out of the apparatus by the pushing action of the suction pump 11, as in the case of the calibration liquid described above, or the calibration liquid in this set of reaction tubes 412. After completing a series of measurement operations for the sample liquid, the analyzer moves on to measurement operations for the next set of reaction frameworks, and by sequentially repeating this measurement cycle, automatic analysis of a large amount of samples is performed.

[When the amount of sample liquid sucked is less than a predetermined value] In (b), when the amount of sample liquid sucked from the supply container into the sample liquid discharge nozzle 6 is less than the predetermined value. In this case, the pressure sensor 23 detects this and transmits a signal of the abnormal suction amount to the control CPU 14.

Upon receiving this signal, the CPU 4 first forcibly stops the movement of the sample liquid discharge nozzle 6 from the suction position (B) to the discharge position (C), and in this state, slightly rotates the transport line 4. The reaction tube 3 for sample liquid is controlled to be set at the position of the calibration liquid discharge nozzle 5, and further, the reaction tube 3 for sample liquid is controlled to be moved from this discharge nozzle 5.
1. The entire analyzer is controlled so as to discharge the calibration liquid into the analyzer. Therefore, the measuring section 8a of the ion electrode 8 continuously measures the electromotive force between the calibration solution in the calibration solution reaction tube 2 and the calibration solution in the sample solution reaction tube 3.

However, since there is essentially no level difference between the measured values between the two, even if such a measurement operation is in between,
There is no adverse effect on the measurement results of the calibration solutions and sample solutions for the other subsequent reaction frameworks 2 and 3.

Then, when the pressure sensor 23 transmits a signal indicating the normal sample liquid suction amount to the control CPU 14, the analyzer returns to its original normal state, or other measurement operations are performed.
This is similar to the normal measurement described above.

Although one embodiment has been described above, the present invention is not limited thereto, and only one embodiment is described without changing the gist of the invention.
For example, in the illustrated example, the pair of reaction skeletons may be arranged in the front-rear direction, or they may be arranged side by side. Further, regarding the dilution of the calibration liquid, a dilution liquid discharge nozzle exclusively for the calibration liquid may be provided so that the sample liquid is diluted at the same time as the sample liquid is diluted.

[Effects of the Invention] As described above, when using the present invention, even if an abnormality occurs in the amount of sample liquid to be subjected to measurement, the electrolyte concentration measurement can be performed without deteriorating the accuracy and the measurement operation can be continued. It is possible to provide a system 1@Dan.

[Brief explanation of the drawing]

The drawing is a schematic configuration diagram of an automatic analyzer to which the electrolyte concentration measurement system according to the present invention is applied.

Claims (3)

[Claims] (1) In an electrolyte concentration measurement system that measures the electrolyte concentration by discharging a calibration solution and a liquid to be measured into each reaction tube, and sequentially introducing both solutions in the reaction tubes into an ion-selective electrode site. When the liquid to be measured is sucked from the supply container, it is detected that the amount of the liquid to be measured does not reach a predetermined value, and a calibration solution is discharged into the reaction tube for the liquid to be measured. An electrolyte concentration measurement system characterized by comprising: (2) The electrolyte concentration measurement system according to claim 1, wherein each of the reaction tubes is a pair of reaction tubes arranged one behind the other with respect to the traveling direction of the reaction tube transport line. (3) The electrolyte concentration measuring system according to claim 1 or 2, wherein the liquid to be measured is a biological fluid such as blood or urine.