JPH02218962A - Specimen suction method and apparatus of analyser - Google Patents

Abstract

PURPOSE:To keep the insertion depth of a nozzle optimum and constant by providing inner and outer electrodes to the leading end of the nozzle and achieving two functions of a switch detecting the liquid level of a specimen and a start switch for starting suction operation by both electrodes. CONSTITUTION:When the tip electrode 311 of a nozzle 30 is inserted in a speci men 100 up to a definite depth, the tip of the external electrode 312 insulated by an insulator 313 is brought into contact with the liquid level of the specimen 100. Whereupon, the potential difference between the electrodes 311, 312 is reduced and a current is supplied between both electrodes. With the supply of this current, the switch 31 constituted of the electrodes 311, 312 is turned ON and the ON-signal thereof is inputted to a detection circuit 34 through a lead wire. On the basis of this ON-signal, it is detected that the electrode 312 is brought into contact with the liquid level of the specimen 100. In response to the input of the output of said circuit 34 to a control part, a signal is sent to a roller pump. By this method, the roller pump is rotationally controlled in a forward direction and, after a predetermined amount of the specimen 100 in a sample cup is sucked in the nozzle 30, the nozzle 30 rises and returns.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a specimen aspiration method and apparatus suitable for use in analysis devices such as blood gas analyzers and electrolyte analyzers.

BACKGROUND OF THE INVENTION An electrolyte analyzer is an apparatus for measuring and analyzing the concentration of ions in a sample using an ion electrode method.

Furthermore, there is a blood gas analyzer as a device that measures and analyzes the concentration of CO2, 02 in blood gas and pH value.

In these analyzers, a sample such as blood or urine is placed in a container such as a sample cup, test tube, or blood collection tube, and the sampling nozzle of the device is inserted into the sample in this container.
A predetermined amount is aspirated and supplied to the measurement electrode section, and necessary inspection items are analyzed and measured.

There are two methods for aspirating a specimen in a container using a sampling nozzle: automatic sampling and manual sampling.

Auto-sampling involves raising and lowering the sampling nozzle for multiple samples that are sequentially fed to the nozzle position, inserting the nozzle into the sample, sucking the sample, supplying it to the measurement electrode, and then analyzing and measuring it. This process is repeated for each sample, and the insertion depth of the nozzle into the sample is fixed in advance. In the case of auto-sampling, the suction operation is performed automatically, so there is no problem in terms of operability and workability of the sample suction process, and there is no burden on the operator.

On the other hand, in manual sampling, a container containing a specimen is held in one hand and the nozzle protruding from the device is inserted into the specimen, and visual confirmation is made to ensure that the nozzle is securely inserted into the specimen. At the same time, a start switch located elsewhere on the device is operated with the other hand to aspirate the sample. Sampling using this technique involves holding the container with one hand and inserting the nozzle into the sample, visually confirming whether the nozzle has been inserted securely, holding the inserted state with one hand, and simultaneously holding the nozzle with the other hand. Since the switch is operated with both hands, it is inevitably a two-handed operation, and both hands must be used to hold the container and operate the switch.
Three operations, including visual confirmation, must be performed at the same time, and there is a problem in that holding with one hand is unstable. In addition, since it is a two-handed operation, it has extremely poor operability, is very troublesome and troublesome, and requires skill. Therefore, manual sampling is not suitable for aspirating multiple samples, and is usually applied when it is desired to analyze and measure a small number of samples (about 1 to 2) on the spot, for example, for emergency testing of a small number of samples.

In order to eliminate the trouble and complexity of the above-mentioned manual sampling operations, two methods have been proposed. One is that a start switch is integrated into the top of the nozzle so that the switch can be operated at the same time as the nozzle is inserted into the sample.
The operating lever of the start switch is extended to a position corresponding to the nozzle, and with the nozzle inserted into the sample, the operating lever is pushed in with the nozzle to operate the switch.

Problems to be Solved by the Invention When a sample is aspirated using a nozzle, the sample, such as blood or urine, is centrifuged in advance to remove impurities. It is normal for impurities such as dirt and other precipitates to accumulate. Therefore, if the nozzle is inserted deeply into the sample, impurities from the bottom of the container will be sucked in along with the sample, which will have a negative effect on the measurement results, so it is not possible to insert the nozzle too deeply. On the other hand, if air gets mixed into the sample aspirated by the nozzle, air bubbles will be generated and, as is well known, this will have a great negative effect on the measurement results. Suction operations that create air bubbles in
Must be avoided at all costs. Therefore, the insertion depth of the nozzle must be maintained at a constant minimum depth, neither too deep nor too shallow, so that it does not suck in impurities from the bottom of the container and also does not suck in air.

In the case of a sample suction method using auto-sampling, if the nozzle is inserted into or removed from the sample at a rapid speed, the liquid will scatter around the sample, so the speed at which the nozzle rises and falls cannot be made too fast. On the other hand, if it is too slow, it will take too much time to move the nozzle up and down for each sample, so it cannot be used. In addition, if the nozzle is inserted deep into the container, in addition to the problem of sucking in impurities as described above, the nozzle's operating stroke for each sample becomes longer, and extra time is required for the nozzle to move up and down. This causes a problem that the processing speed of the sample aspiration step cannot be increased.

Therefore, in order to minimize the movement stroke of the nozzle and shorten the time required for its movement, it is necessary to insert the nozzle into the sample at a depth that does not cause problems such as suction of impurities and air as described above. It is desirable to set it as shallow as possible.

However, in the conventional autosampling sample aspiration method, for multiple samples set in one autosampler, the insertion depth of the nozzle into the container is determined to be constant, so the amount of sample inside the container is fixed. If too much or too little has entered, the liquid level will not be uniform for each sample, and the nozzle may not be able to be inserted into the sample at the above-mentioned optimum depth. Therefore, the conventional suction method using auto-sampling has the problem of keeping the insertion depth of the nozzle constant at the optimum depth, and also requires a separate detector to detect the start of suction operation and a start mechanism for that purpose. There are many problems to be solved regarding the device configuration.

On the other hand, the two sampling methods using the above-mentioned techniques are
This eliminates the trouble and complexity of the conventional two-handed sample aspiration operation, and improves operability to some extent, but it requires the hand holding the container to move the nozzle and operate switches and levers. Moreover, at that time, the nozzle must be visually checked to see if it has been inserted into the specimen at a certain depth, and the specimen must be aspirated while maintaining this constant state by hand, resulting in poor handling. , the complexity of operation, troublesomeness, and troublesomeness still exist. Therefore, it is an important issue to further improve the handling and Φ operability when using manual techniques.

This invention has been proposed in view of the above points, and has a function of a start switch at the tip of the nozzle, so that the depth of insertion of the nozzle into the sample can be maintained constant at all times, and also allows the nozzle to be inserted into the sample at all times. The object of this invention is to enable the nozzle to automatically start the specimen suction operation by detecting the liquid level when the nozzle is inserted to a certain depth.

Means for Solving the Problems In order to achieve the above object, the present invention employs a specimen aspiration method having the following configuration.

That is, in the present invention, at least the tip of a sampling nozzle that aspirates a sample and supplies it to a measurement electrode section is formed of a conductive material to serve as an internal electrode, and the tip is spaced a predetermined distance from the nozzle tip on the outside of the sampling nozzle to form an external electrode. With the electrodes arranged and a potential difference created between the inner and outer electrodes, the nozzle is inserted into the sample in the container, and conduction is established between the inner and outer electrodes by contact with the sample liquid surface of the outer electrode, and the inner and outer electrodes are electrically connected. The present invention is characterized by a sample aspiration method in which a sample aspiration operation by a nozzle is started based on an on signal of a switch consisting of the following.

Furthermore, the gist of the present invention is a specimen aspiration device having the following configuration.

In the present invention, at least the tip of a sampling nozzle that aspirates a sample and supplies it to a measurement electrode section is formed of a conductive material to serve as an internal electrode, and the tip is placed on the outside of the nozzle at a predetermined distance backward from the nozzle tip. A detection switch is configured between the inner and outer electrodes, and when the outer electrode comes into contact with the sample liquid surface by inserting the nozzle, the switch configured between the inner and outer electrodes responds to the input of an on signal. The present invention is characterized by a specimen suction device that starts a specimen suction operation. The external electrode may be either cylindrical or bar-shaped, which is fitted onto the outside of the internal electrode, and both are included in the structure of the present invention. When the external electrode is cylindrical, an insulator is interposed between the inner and outer electrodes.

Further, the sample aspiration device according to the present invention is provided with a detection circuit that detects an on signal of a switch composed of internal and external electrodes,
It is characterized by adopting a configuration in which the sample suction means communicating with the nozzle is operated based on the detected output of the on signal.

Action When the nozzle is inserted into the sample in the container to a certain depth when aspirating the sample, the external electrode comes into contact with the liquid surface of the sample, and the potential difference between the inner and outer electrodes becomes 0, creating a state with no resistance. As a result, conduction occurs between the inner and outer electrodes, and electricity is supplied.

As a result, a switch configured between the inner and outer electrodes is turned on, and the sample suction means communicating with the nozzle is activated based on the detected output of the on signal. Therefore, by detecting the contact of the external electrode with the liquid surface, the insertion depth of the nozzle into the sample can be easily and reliably controlled and maintained at an optimal constant depth at all times. Moreover, the specimen suction operation by the nozzle can be started at the same time as the nozzle is inserted into the specimen to a certain depth. As a result, in the case of manual sampling, there is no need to visually check the insertion depth of the nozzle or to move the nozzle through the container and separately operate the start switch or switch lever.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an external perspective view of an electrolyte analyzer shown as an embodiment of the present invention, and FIG. 2 is a block diagram showing its specific circuit configuration.

A measuring section 12 is disposed on the front right side of the apparatus main body 1.

A sample suction nozzle (hereinafter simply referred to as a nozzle) 30 that is integrally connected to the electrode section 5 is supported on the left side of the front surface thereof. The nozzle 30 is integrated with the electrode section 5.

The nozzle 30 is moved up and down by the up and down mechanism 21 at the sample suction position, and sucks the sample from a container such as a sample cup. The suction operation is performed by rotating the roller pump 11 in the forward direction. That is, the nozzle 30 communicates the flow path of the specimen to the electrode section 5, and also connects each ion electrode 2OA, 20812 of Nas Ks C1 of this electrode section 5.
It is connected to a roller pump 11 via a reference electrode 20D and a flow sensor 19, and a predetermined amount of a sample is sucked from the sample cup by rotating the roller pump 11 in the forward direction of the sample suction direction (clockwise in the figure).

Further, the nozzle 30 is connected to the three-way valve 7 through the septum.
．． 8 and, through this three-way valve 7.8, to a container of standard solution 1.2. three-way valve 7
．． 8 are each connected to a pinch valve 9.10. The valve 7.8 is controlled to open and close on and off in response to a signal from the control section 16.

Standard solution 1 is used as a calibration solution. At the time of ion concentration measurement, the standard solution 1 sucked into the nozzle 30 is applied to each of the ion electrode parts 2OA, 20 with a concentration of %N a 1C1 in the electrode part 5.
B, filled with 20C.

On the other hand, the standard solution 2 is a calibration solution like the standard solution 1, and when the three-way valve 8 is opened to the nozzle 30 side and the roller pump 11 is rotated forward, the nozzle 3 passes through the valve 8 and the septum.
0, each of the ion electrode parts 20A to 20 of the electrode part 5
Filled with C. At this time, it goes without saying that the reference electrode liquid Ref is filled in the reference electrode portion 20D in advance by the forward rotation of the roller pump 11. At this time, both three-way valves 7.8 are closed. and - three-way valve 7
．． 8, when one is open, the other is closed, and when the other is open, one is closed.

Opening/closing is controlled in this way.

Each ion electrode 20A to 20C1 reference electrode 20 of the electrode section 5
The signals from D1 and the flow sensor 19 are A/D converted by an analog/digital converter and then input to the controller 15, where they are subjected to arithmetic processing and signal processing. The result is printed out from the printer section 13, and at the same time,
It is displayed on the display section 14.

In the figure, reference numeral 16 denotes a power supply section that supplies driving power to the control section 15 and each section.

Next, FIGS. 3 and 4 show the main parts of the sample aspiration device according to the present invention, in which the nozzle 20 penetrates the center of the septum 17 and can move up and down with a constant stroke. ing. That is, the through hole 17 is formed in the center of the septum 17.
1 is formed, and the nozzle 30 is supported in this through hole 171 so as to be vertically movable via upper and lower rubber seal members. The standard solution 1.0 is supplied to the tip of the nozzle 30 via the three-way valve 7.8 and the flow path 172A1172B of the septum 17.
2 is now supplied.

The nozzle 30 is made of a conductive resin material, ceramics, etc. or a metal material, and its tip 311 is an internal electrode 3 that constitutes a switch 31 that detects the liquid level of the specimen in the sample cup.
It is 11. A cylindrical external electrode 312 is fitted onto the outside of the tip of the nozzle 30 with an insulator 313 interposed therebetween.

The external electrode 312 is made of a conductive resin material, ceramics, etc., or a metal material, and its tip is spaced a predetermined distance d from the tip of the nozzle 30, that is, the tip of the internal electrode 311 to the rear side of the nozzle.
are placed in a spaced relationship. That is, the inner and outer electrodes 311 and 312 are in such a relationship that the tip of the inner electrode 311 projects from the tip of the outer electrode 312 by a distance d. The inner and outer electrodes 311 and 312 constitute a detection switch 31 that detects the liquid level when the nozzle 20 is inserted into the sample cup and starts the sample suction operation based on the detection.

Internal electrode 311 is connected to external power source 32 . External electrode 312 is grounded. When the nozzle 30 performs a sample suction operation, a potential difference approximately equal to the power supply voltage of the external power supply 32 is generated between the inner and outer electrodes 311 and 312. Further, the inner and outer electrodes 311 and 312 are connected to a circuit 34 that detects an ON signal of the switch 31 via lead wires 33 and 33. The detection circuit 34 is connected to the control section 15. This detection circuit 34 can be configured with TTL logic, an operational amplifier circuit, a voltage comparator circuit, and the like.

Next, a specimen aspiration method of the present invention using the above device will be described.

In the above configuration, the amount of sample sucked from a container such as a sample cup by the nozzle 30 is determined by the roller pump 11.
The rotation speed or rotation time of the rotation speed is controlled by the control unit 15 to a predetermined setting value.

First, a sample is placed in a sample cup (hereinafter referred to as a cup) to prepare for measurement.

As shown in FIG. 5, when the nozzle 30 sucks the sample in the cup, when the tip electrode 311 of the nozzle 30 is inserted into the sample 100 of the cup to a certain depth, the external electrode 3
12 comes into contact with the liquid surface of the specimen 100. Then, the potential difference between the inner and outer electrodes 31L312 disappears, and the electrode 311
．． A current is applied between 312 and 312.

When a current is applied between the inner and outer electrodes 31L312, the switch 31 composed of the picture electrodes 311 and 312 is turned on, and the on signal is input to the detection circuit 34 via the lead wires 33 and 33. Based on the input of this ON signal, it is detected that the external electrode 312 has come into contact with the liquid surface of the sample 100.

In response to the liquid level detection output being input to the control section 15, a signal is sent from the control section 15 to the roller pump 11. As a result, the roller pump 11 is rotated in the forward direction.
A predetermined amount of the specimen 100 in the sample cup is sucked into the nozzle 30 . Then, after a predetermined amount of the sample 100 in the cup has been suctioned, the nozzle 30 returns to -E.

The above is the operation and procedure of specimen aspiration according to the method of the present invention. According to this sample suction method, the roller pump 1
1 is immediately controlled to rotate, and the sample 100 is removed by the nozzle 30.
The suction operation starts at the same time as the liquid level is detected. Moreover,
The nozzle tip 311, that is, the internal electrode 311 has a length d that corresponds to the protrusion length d from the external electrode 312.
Since the suction operation of the sample by the nozzle 30 immediately starts when the sample 100 is inserted to a certain depth into the sample 100, the insertion depth of the nozzle 30 from the liquid level of the sample 100 is always accurately controlled to be constant. Therefore, the specimen suction operation by the nozzle 30 can always be carried out at an optimal depth where the insertion depth into the specimen is not too deep and does not simultaneously suction impurities at the bottom of the container or suck air to create bubbles. Moreover, the tip of the nozzle also serves as an electrode for detecting the liquid level, and in combination with the external electrode 312 constitutes the detection switch 21, so that the sample suction operation is started immediately upon detection of the liquid level. There is no need to adopt a complicated structure such as providing a mechanism or a circuit to control the drive, and the structure for detecting the liquid level and starting the suction operation of the specimen is simple, and moreover, the operation can be controlled reliably. Furthermore, if the structure is such that the separation distance d between the tips of the internal electrode 311 and the external electrode 312 at the tip of the nozzle can be variably adjusted, the liquid level of the nozzle 30 can be adjusted depending on the amount of sample in the container, the type of sample, etc. The insertion depth can be adjusted to the optimum depth.

In cases such as emergency testing, when it is necessary to measure and test about one or two specimens, manual sampling is employed. When using manual techniques, a container containing a predetermined amount of specimen is held in hand, and the tip of the nozzle 30 protruding from the device is inserted into the specimen in the container.

When the nozzle 30 is inserted to a certain depth, the tip of the external electrode 312 comes into contact with the liquid surface of the sample as in the example shown in FIG. Turns on. The rotation of the roller pump 11 is controlled based on the ON signal, and the sample suction operation by the nozzle 30 is started. That is, even in the case of manual specimen aspiration, the specimen aspiration operation starts immediately upon detection of the liquid level by the switch 31. Therefore, the nozzle 30 serves both as a liquid level detection switch and a start switch for starting the sample aspiration operation, and the sample aspiration operation starts automatically only by inserting the nozzle tip into the sample to a certain depth, so there is no separate aspiration operation. There is no need for a start switch or switch operation to start the process.

Moreover, there is no need to visually check whether or not the nozzle 30 has been inserted to a certain depth; simply inserting the nozzle 30 into the sample can maintain it at a constant insertion depth; Suction operation can be started.

Next, an outline of ion concentration measurement will be explained.

As shown below, the sample is aspirated through the nozzle 30,
It is supplied to the measurement electrode section 5, and a potential according to the ion concentration is measured.

First, the three-way valve 8 is switched to the nozzle 30 side and opened, and the standard solution 2 is sucked through the nozzle 30 by the forward rotation of the roller pump 11, filling each of the ion electrode parts 20A to 20C of the electrode part 5.

At this time, the reference electrode 2OD is filled with a reference electrode solution in advance. Then, 1N a N for each ion concentration
The electrode potential corresponding to CI N .

Next, in the same procedure, switch the three-way valve 7 to the nozzle 30 side and open it, fill each ion electrode 20A to 20C of the electrode section 5 with the standard solution 1, and then detect and measure the electrode potential according to the ion concentration. do. This series of operations completes the measurement calibration operation.

Next, a predetermined amount of the sample is sucked into the nozzle 30 from the cup. This suction operation is performed according to the above procedure. The sample sucked into the nozzle 30 passes through the flow path and flows into the ion electrode sections 2OA120B and 20C in sequence. During this flow process, an electrode potential corresponding to the concentration of ions such as k 1N a%CI contained in the sample is measured. The ion concentration in the urine sample is calculated based on the A/D converted value and the measured value obtained from the standard solution 1.2. The result is printer section 1
3 is printed out and simultaneously displayed on the display section 14. In this way, sample suction and measurement of ion concentration are performed sequentially for each sample. When collecting a sample, the operations and procedures of the aspiration method according to the present invention are adopted.

Note that the present invention can be applied not only to whole blood, serum, urine, etc., but also to all conductive liquids as target specimens. Furthermore, the present invention is applicable not only to an apparatus in which a sample cup is held by hand, but also to an apparatus equipped with an autosampler for multiple samples.

Furthermore, the present invention is not limited to electrolyte analyzers, but is also applicable to CO
2,02, it is widely applicable to analyzers that involve sample suction through a nozzle, such as blood gas analyzers that measure pH values.

The above-mentioned external electrode is not limited to the cylindrical one shown in FIGS. 3 and 4, but can also be of various structures, such as lever-shaped, bar-shaped, rod-shaped ones, etc. FIG. 6 shows an example of this, in which a bar-shaped external electrode 312' is disposed outside the tip electrode 311 of the nozzle 30. The tip of the external electrode 312'' is the internal electrode 31 provided at the tip of the nozzle.
It is spaced a distance d backward from the tip of 1. That is, the tip of the nozzle 30 projects a distance d from the tip of the external electrode 312'. Internal electrode 311 and external electrode 31
2' has two switch functions: a switch that detects the liquid level of the sample, and a start switch that starts the sample suction operation upon detection. This is similar to the above embodiment. Therefore, this embodiment can also provide the same effects as those of the above embodiment.

As described in detail, according to the present invention, the nozzle has internal and external electrodes at its tip, a switch or sensor for the nozzle to detect the liquid level of the sample, and a start switch that starts the suction operation of the sample based on the detection. Since it has two functions, when the nozzle tip is inserted into the sample, the sample suction operation can be started immediately by detecting the liquid level. Even in the case of sampling, the suction operation can be started immediately upon insertion of the nozzle to a certain depth. Therefore, the insertion depth of the nozzle into the sample can be easily and reliably controlled by liquid level detection, and the insertion depth can always be maintained at a constant, optimal insertion depth, regardless of the sampling method. Furthermore, as soon as the nozzle is inserted to a certain depth, the sample suction operation can be started immediately by liquid level detection, so it is possible to visually check whether the nozzle has been inserted to a certain depth or not. There is no need for complicated operations such as operating the start switch or switch lever, and it eliminates the complexity, operability, and poor handling of sample aspiration, especially when manually performed, and simplifies and simplifies sample aspiration operations. It is possible to achieve rapid processing and further improve operability and handling.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing the overall configuration of an electrolyte analyzer to which the present invention is applied, Fig. 2 is a block diagram showing its specific circuit configuration, and Figs. 3 and 4 show main parts of the present invention. FIG. 5 is a cross-sectional view showing the specimen aspirating operation and procedure according to the present invention. FIG. 6 is a sectional view of the nozzle tip, which is the main part of the present invention. 312. 313・ 34・ ・ 11 fist ・ 15・ housing 12′・φ・external electrode, ・insulator, detection circuit, roller pump, control section. 20... Electrode part, 30... Nozzle, 31... Detection switch, 311... Internal electrode, Fig. 3 Fig. 4

Claims (6)

[Claims] (1) At least the tip of a sampling nozzle that aspirates the sample and supplies it to the measurement electrode section is made of a conductive material to serve as an internal electrode, and the tip is placed a predetermined distance backward from the nozzle tip on the outside of the sampling nozzle. Arranging the electrodes,
With a potential difference created between the outer electrodes, the nozzle is inserted into the sample in the container, and conduction is established between the inner and outer electrodes by contact of the outer electrode with the sample liquid surface. ,
1. A method for aspirating a sample in an analyzer, characterized in that the nozzle starts a sample aspiration operation based on a liquid level detection signal from an external electrode. (2) A method for aspirating a specimen in an analyzer according to claim (1), characterized in that a detection switch is configured between the inner and outer electrodes, and the specimen aspirating operation by the nozzle is started based on an on signal from the detection switch. (3) At least the tip of the sampling nozzle that aspirates the sample and supplies it to the measurement electrode section is made of a conductive material to serve as an internal electrode, and the tip is placed a predetermined distance backward from the nozzle tip on the outside of the sampling nozzle. electrodes are arranged, a detection switch is configured between the inner and outer electrodes, and when the outer electrode comes into contact with the sample liquid surface by insertion of the nozzle, an on signal is input to the switch composed of the inner and outer electrodes. A specimen aspiration device of an analyzer configured to start an aspiration operation of the specimen in response. (4) The analysis according to claim (3), characterized in that a cylindrical external electrode is fitted and attached to the outside of the internal electrode formed by the nozzle, and an insulator is interposed between the inner and outer electrodes. Specimen suction device of the device. (5) Claim (3) characterized in that a bar-shaped external electrode is disposed outside the internal electrode formed by the nozzle.
) Specimen suction device for the analyzer described in ). (6) Provide a detection circuit to detect the on signal of the switch,
The specimen suction device for an analyzer according to claim 1, wherein the specimen suction means communicating with the nozzle is operated based on the detection output of the on signal.