JPH0348463B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode for measuring the pH of blood, and an object thereof is to provide an electrode that allows continuous measurement over a long period of time without requiring maintenance of the electrode.

Blood PH measurements are often taken as an aid in the diagnosis of respiratory and circulatory system diseases. Conventionally, glass electrodes have been most commonly used among various electrodes for this PH measurement. The reference electrode used as a pair with this glass electrode is usually a saturated aqueous electrode or a silver-silver chloride electrode. However, if these pair of electrodes are used as they are to measure the pH of blood, blood clots will form on the electrode surface after long periods of use, resulting in poor reproducibility of the measured values. Therefore, it is necessary to frequently interrupt the measurement for maintenance and inspection such as cleaning the electrodes, and it is currently extremely difficult to carry out continuous measurements over a long period of time.

Therefore, in the present invention, the glass sensitive membrane surface of the solid-state glass electrode and the liquid junction part of the reference electrode are opposed to each other at a certain distance, and a sample chamber through which the test blood passes is formed in this opposed part. a magnetic rotor capable of contacting the glass sensitive membrane surface and the liquid junction portion is enclosed in the electrode, and the magnetic rotor is configured to be rotationally driven by a rotating magnetic field acting from outside the sample chamber. The action of the surface and the magnetic rotor that rotates while in contact with the surface prevents blood from depositing on the electrodes and keeps them in a clean state at all times.The effect is that continuous measurement can be performed over a long period of time without maintenance and inspection. There is.

An embodiment of the present invention will be described below along with a conventional electrode structure.

FIG. 1 shows a longitudinal section of an electrode for pH measurement according to the present invention. 1 is a solid glass electrode, 2 is a glass electrode 1
The reference electrode 3 located above is a plastic plate that holds the glass electrode 1 and the reference electrode 2 with a constant distance between the glass sensitive membrane surface 4 of the glass electrode 1 and the liquid junction part 5 of the reference electrode 2. A small diameter part 6 is formed in the middle part of the inner peripheral surface of the cell, and step parts 7 and 8
O-rings 9 and 10 are interposed between the glass electrode 1 and the reference electrode 2, respectively, and the sample is surrounded by the inner peripheral surface of the cell 3, the glass sensitive film surface 4, and the liquid junction 5. A chamber 11 is configured. 12,
Reference numerals 13 denote a lower lid and an upper lid respectively attached to the ends of the cell 3. The lower lid 12 prevents the glass electrode 1 from moving away from the O-ring 9, and the upper lid 13 prevents the reference electrode 2 from moving away from the O-ring 9. Movement in the direction away from the O-ring 10 is restricted. 14,
Reference numeral 15 indicates an inlet and an outlet for the test blood 16, which communicate the outside of the cell 3 and the inside of the sample chamber 11, and 17
is a magnetic rotor enclosed in the sample chamber 11 of the cell 3, and the surface of the magnetic material is coated with a resin containing an abrasive such as alumina, or the surface of the magnetic material is coated with a soft puff. 18
is a magnetic body for generating a rotating magnetic field disposed outside the sample chamber 11, and is rotated by a motor (not shown) to generate the magnetic rotor 17 inside the sample chamber 11.
Rotate horizontally. Incidentally, the magnetic rotor 17 is formed in a size such that it comes into contact with the glass sensitive film surface 4 and the liquid junction portion 5 at least during rotation.

Generally known glass electrodes include
There are two types: the internal liquid type shown in the figure and the solid type shown in Figure 3. First, the internal liquid type glass electrode contains an electrolytic solution 21 such as hydrochloric acid or phosphate aqueous solution, mercury, A cap 24 is placed over a cap 24 containing an electrode 23 with a lead wire 22 made of Hg ₂ Cl ₂ and a potassium chloride solution. This internal liquid type has an electrolyte 21 inside, so when using it,
As shown in FIG. 2, it must be used in an upright position with the glass sensitive film 20 facing down, and is not suitable as the glass electrode shown in FIG. 1. A solid-state type is described in Japanese Patent Publication No. 53-318. That is, as shown in FIG. 3, a 10% silver fluoride aqueous solution is applied to one side of a lithium glass-based glass sensitive film 25 sliced into a thin disk shape of 3 to 30 mm in diameter and 50 to 500 microns in thickness and dried. let Such treatment was carried out several times to form a silver fluoride layer on the glass sensitive film 25, and after leaving it for a day and night, it was immersed in a 5% lithium chloride solution and left for about 20 hours to form a silver fluoride layer. The layer is changed to a silver chloride layer 26 from which electromotive force can be extracted more stably. After washing this with water, heat it at 300℃ for 2
The adhesion between the glass sensitive film 25 and the silver chloride layer 26 is improved by heat treatment in argon or nitrogen for a period of time. Thereafter, a lead wire 28 is connected to the silver chloride layer 26 using a conductive resin 27 such as silver paint, and further hardened with a resin 29 from above to form a rod-shaped glass electrode. In addition, the glass sensitive film 2
The exposed part 5 is well polished before use in order to stably extract the electromotive force. Unlike the liquid type shown in FIG. 2, this solid type does not have an electrolytic solution inside, so it is suitable for disposing the glass sensitive membrane 4 with the glass sensitive membrane 4 facing upward as shown in FIG.

Further, as a reference electrode, a so-called silver-silver chloride electrode is generally used as shown in FIG. This consists of a silver-silver chloride electrode 34 connected to an electrolytic solution 32 made of an aqueous solution such as potassium chloride and a lead wire 33 to extract an electromotive force to a glass cylinder 31 with a pinhole 30 at its tip as a liquid junction. They are each placed in a container and covered with a cap 35. In addition, instead of the pinhole 30, a sleeve type using polished glass or a fiber type using fiber can be similarly used for the liquid junction.
Instead of the glass cylinder 31, a Teflon container may be used, and the liquid junction may be provided with porous Teflon, and any of these may be used as the reference electrode 2 shown in FIG.

Since the embodiment shown in FIG. 1 is configured as described above, the glass sensitive film surface of the glass electrode 1 is rotated by rotating the magnetic rotor 17 within the sample chamber 11 by applying a rotating magnetic field from outside the cell 3 during measurement. 4
and the liquid junction part 5 of the reference electrode 2 are respectively connected to the magnetic rotor 1
The contacting and rotating action of 7 prevents blood from depositing on its surface, allowing it to remain clean even after long-term use.

As explained above, according to the present invention, the rotation of the magnetic rotor prevents blood from depositing on the glass sensitive surface of the glass electrode and the surface of the liquid junction of the reference electrode, thereby constantly maintaining a clean state. The reproducibility of measured values is greatly improved, and the continuous measurement of blood PH, which has been desired in the field of clinical medicine, can be easily achieved. Furthermore, since the glass sensitive membrane surface of the solid-state glass electrode and the liquid junction of the reference electrode correspond to each other at a constant distance, the sample chamber can be made smaller, making it particularly suitable for microanalysis of blood.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of the blood PH measuring electrode of the present invention, FIGS. 2 and 3 are vertical cross-sectional views of a conventional glass electrode, and FIG. 4 is a vertical cross-sectional view of an example of a conventional reference electrode. FIG. DESCRIPTION OF SYMBOLS 1...Solid glass electrode, 2...Reference electrode, 3...Cell, 4, 25...Glass sensitive surface, 5...Liquid junction, 7,
8... Step part, 9, 10... O-ring, 11... Sample chamber, 14... Inlet, 15... Outlet, 16... Test blood, 17... Magnetic rotor, 18... Magnetic material.

Claims (1)

[Claims] 1. The glass-sensitive film surface of the solid-state glass electrode and the liquid junction of the reference electrode are opposed to each other at a constant interval, and a sample chamber through which the test blood passes is formed in this opposing portion, and the glass-sensitive membrane surface of the solid-state glass electrode is formed in this sample chamber through which the test blood passes. An electrode for blood PH measurement, which includes a magnetic rotor that can come into contact with a membrane surface and the liquid junction, and is configured to rotate the magnetic rotor by a rotating magnetic field that acts from outside the sample chamber.