JPH0610309Y2 - Diffusion limiting membrane holder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a diffusion limiting film holder, and more specifically, it is a diffusion that is preferably used to adhere the diffusion limiting film to the surface of the concentration measuring electrode. Restriction membrane holder

<Prior Art> Conventionally, a physiologically active substance is immobilized on the surface of an electrode, paying attention to the characteristic that it can detect extremely complicated organic compounds, proteins, etc. with extremely high sensitivity and selectively. Research and development have been conducted to measure the above-mentioned organic compounds, proteins and the like by means of enzyme electrodes.

When the target substance is measured using the enzyme electrode, normally, the target substance to be measured is oxidized or reduced in the presence of the physiologically active substance, and the amount of the produced substance or the lost substance is measured. Since the concentration of the substance to be measured is measured by the measurement, the upper limit of the measurable concentration is limited by the existing amount of the substance that causes oxidation, reduction, etc., such as oxygen.

Focusing on such a point, an attempt has been made to increase the measurement limit concentration by attaching a diffusion limiting membrane on the surface side of the immobilized enzyme membrane on which the physiologically active substance is immobilized and limiting the permeation rate of the substance to be measured. .

Specifically, a configuration is adopted in which a diffusion limiting film is attached to a cap screwed to a rod-shaped enzyme electrode base, and the diffusion limiting film is automatically attached to the immobilized enzyme film by screwing the cap. There is.

Further, by adopting such a configuration, the diffusion limiting film limits the permeation rate of the substance to be measured and enables measurement up to a considerably high concentration. Further, the diffusion limiting film is removable in order to eliminate the influence of the interfering substance contained in the solution to be measured (for example, increase in the diffusion limiting effect due to the adhesion of the interfering substance) and perform good measurement. The screwing mechanism by the cap is adopted.

<Problems to be Solved by the Invention> When the diffusion limiting membrane holder having the above configuration is adopted, the diffusion limiting membrane can be exchanged relatively easily. There is a problem that attachment and detachment becomes very difficult depending on the situation, and it becomes impossible to achieve a uniform adherence state to the immobilized enzyme membrane depending on the amount of force applied during screwing.

In addition, when the enzyme electrode base has a small diameter and, as a result, the cap becomes small, the manual operation becomes very difficult, and the above problem becomes more remarkable.

Further, since the diffusion limiting film is attached to the cap, there is a problem that the space required for storage and transportation becomes large.

In consideration of such problems, a diffusion limiting film holder having a configuration in which an opening is formed at a predetermined position of a thin plate having a predetermined shape and a diffusion limiting film is attached so as to cover one side of the opening is adopted. It is possible to measure the concentration of the test solution while the restriction membrane is in pressure contact with the immobilized enzyme membrane, but since the enzyme electrode is generally small, the diameter of the opening formed in the thin plate also becomes small. Therefore, it becomes extremely difficult to accurately drop the test solution at the opening position. In consideration of such problems, it is possible to make the surface of the thin plate water-repellent and to make only the inner wall of the opening hydrophilic, but the property of positively guiding the test solution to the opening Since it does not have, it is necessary to make the dropping position of the test solution considerably accurate, and if the dropping position is incorrect, a sufficient amount of the test solution will not be guided to the enzyme electrode, Concentration measurement work becomes difficult.

<Purpose of Invention> This invention was made in view of the above problems.
Even if the precision of the dropping position of the test solution dropped on the thin plate is low, the test solution can be reliably guided to the diffusion limiting film, and the attachment / detachment operation of the diffusion limiting film with respect to the concentration measuring electrode can be significantly simplified. An object of the present invention is to provide a diffusion limiting film holder capable of achieving the above.

<Means for Solving Problems> In order to achieve the above-mentioned object, the diffusion limiting film holder of the present invention has an opening for passing a test solution at a predetermined position of a thin plate having a predetermined shape. A diffusion limiting film is attached to one side surface of the thin plate so as to cover the opening, and a permeable membrane covering at least a part of the opening is attached between the thin plate and the diffusion limiting film.

However, it is preferable that the surface of the thin plate has water repellency.

Further, it is preferable that the permeable membrane is a narrow membrane and is attached so as to be aligned with the center of the opening.

Further, it is preferable that the permeable membrane is subjected to a hydrophilization treatment, and a cloth made of degreased natural fibers, hydrophilized organic polymer fibers, glass fibers, carbon fibers or the like. Membranes formed in the shape of or in a non-woven fabric can be used.

Specifically, filter paper, absorbent paper, cotton, linen, absorbent cotton and other natural fibers, vinylon, acetate, nylon, acrylic, polyester, polyurethane, polyethylene, polypropylene, polyvinyl chloride and other organic polymer fibers, glass fibers, Carbon fiber or the like can be used.

<Operation> With the diffusion limiting film holder having the above structure, an opening for passing a test solution is formed at a predetermined position of a thin plate having a predetermined shape, and diffusion limiting is performed on one side surface of the thin plate so as to cover the opening. Since the membrane is attached and the permeable membrane that covers at least a part of the opening is attached between the thin plate and the diffusion limiting membrane, the test solution dropped on the thin plate is slightly permeable. As long as the membrane is in contact with the membrane, the permeable membrane can actively suck the test solution and guide most of the dropped test solution to the diffusion limiting membrane. As a result, it is not necessary to improve the positional accuracy when dropping the test solution,
The workability for measuring the concentration can be significantly improved.
However, since the test solution will be contained in the permeable membrane, it is necessary to increase the required amount of the test solution. Since it is possible to suppress the increase in the amount of the solution, there is no particular inconvenience.

When the surface of the thin plate has water repellency, the amount of the test solution remaining on the thin plate can be significantly reduced when the dropping position is displaced, and the surface of the thin plate has a hydrophilic property. Compared with the case where it has, the increase amount of the test solution can be significantly suppressed.

Further, when the permeable membrane is a narrow membrane and is attached so as to match the center of the opening, the amount of the test solution contained in the permeable membrane is suppressed to the necessary minimum. Therefore, the increase amount of the test solution can be further suppressed.

Further, when the permeable membrane is hydrophilized, the test solution is sucked more positively, so that the dropped test solution is more reliably guided to the diffusion limiting film. be able to.

<Example> Hereinafter, detailed description will be given with reference to the accompanying drawings illustrating an example.

FIG. 1 is a plan view showing an embodiment of the diffusion limiting film holder of the present invention, and FIG. 2 is a longitudinal sectional view showing resistance to a test solution and a certain degree of flexibility. A circular opening (2) is formed at a position separated from one short side of the substantially rectangular thin plate (1) having a circular opening (2), and the lower surface of the thin plate (1) covers the opening (2). Thus, the diffusion limiting film (3) is attached by adhesion or the like. A filter paper (4) is attached between the thin plate (1) and the diffusion limiting film (3) so as to cover the opening (2). Incidentally, the thin plate (1) has a positioning hole (5) at a predetermined position in the central portion thereof, and the one short side (6)
Is formed in an arc shape, and the other short side (7) serves as a grip portion.

Fig. 3 is a plan view showing the main part of the blood glucose level measuring device, and Fig. 4 is a longitudinal sectional view. An enzyme electrode (8) is attached at a predetermined position on the base so that the electrode surface projects upward. At the same time, it has a through hole (10) through which the enzyme electrode (8) can be inserted, and has a housing groove (11) for housing the diffusion limiting film holder at a predetermined position of the diffusion limiting film holder mounting member (9). Engaging portions (12) and (13) are provided at opposing positions across the through hole (10), that is, at the innermost position and at a predetermined position near the side where the diffusion limiting film holder is inserted and removed. More specifically, the engagement portion (12) has an engagement recess (12a) whose inner depth is formed in an arcuate surface having the same radius of curvature as the short side (6). , The engaging recess
It has a ridge (12b) which constitutes an upper regulating protrusion of (12a).

The ridge (12b) may have a wide width over the entire width of the engaging recess (12a), or may be narrower than the entire width of the engaging recess (12a). Good. The engaging portion (13) is an upright portion having a planar shape that is substantially the same as the planar shape of the positioning hole (5). The surface of the enzyme electrode (8) is formed into a substantially arcuate surface.

When the blood (14) is dropped onto the diffusion limiting film holder having the above-mentioned configuration, the blood (14) is placed near the opening (2) with the diffusion limiting film holder placed on any surface. It suffices if it is spotted, and if part of the spotted blood (14) is in contact with the filter paper (4),
The blood (14) is sucked into the filter paper (4) from the contact part, and the dropped blood (14) is sucked into the filter paper (4). ).

When the diffusion limiting film is attached to the blood glucose measuring device having the above configuration, the short side (6) of the thin plate (1) is engaged with the recess ( 12a), then
With the thin plate (1) housed in the housing groove (11) so that the diffusion limiting film (3) faces the through hole (10) (see FIG. 5A), the diffusion limiting film holder attachment member (9) By moving downward, the surface of the enzyme electrode (8) relatively projects from the through hole (10) and can be brought into close contact with the diffusion limiting membrane (3) attached to the diffusion limiting membrane holder ( (See Figure 5, B).

Therefore, in this state, the blood (14) permeates the filter paper (4) and reaches the diffusion limiting film (3), but the diffusion limiting film (3) limits the diffusion of the substance to be measured, and the concentration is increased to some extent. Since it is guided to the enzyme electrode (8) in a low state, even if the glucose concentration in the blood is high,
The concentration of glucose can be measured on the basis of much lower diffusion-limited concentrations.

Further, after the measurement is completed, the diffusion limiting film (3) can be easily removed by operating in the reverse of the above-mentioned mounting.

Further, in the above embodiment, the opening (2) is subjected to a hydrophilic treatment, and the thin plate (1) may be subjected to a water repellent treatment in a portion close to the opening (2). Is a diffusion limiting film that allows the dropped blood (14) to flow more smoothly.
Can lead to (3).

As is clear from the above description, the replacement diffusion limiting film
(3) is attached to the thin plate (1) together with the filter paper (4), and since the overall thickness is considerably thin, it is possible to make it bulky by stacking multiple sheets. It can be stored and transported reliably in a small space.

Incidentally, the diffusion limiting film (3) is one that has a high diffusion limiting effect on glucose while blocking the permeation of large particles such as blood cells in blood (for example, cellophane having a predetermined count).
The diffusion limiting membrane having a high diffusion limiting effect on glucose is attached to the enzyme electrode (8) in advance, and the diffusion limiting membrane (3) attached to the thin plate (1) is used as a diffusion limiting membrane for glucose. It is possible to use a material (for example, a polycarbonate membrane having a predetermined pore size, pore density, etc.) that has a relatively low effect and can reliably block the passage of large particles such as blood cells. Can keep the diffusion limiting effect on glucose as a whole of both diffusion limiting membranes almost constant, and as a result,
It is necessary to replace the diffusion limiting membrane (3) that has been clogged with large particles, and despite the diffusion limiting membrane (3) being replaced, the diffusion limiting effect varies considerably, but the blood glucose level measurement accuracy Can be improved.

<Embodiment 2> FIG. 6 is a plan view showing another embodiment. The difference from the above embodiment is that the shape of the filter paper (4) has a narrow width capable of covering only the central portion of the opening (2). However, the other parts have the same configuration.

Therefore, in the case of this example, the amount of blood (9) impregnated in the filter paper (4) can be remarkably reduced, and the blood amount required for measuring the blood glucose level is remarkably reduced. be able to.

However, in the case of this example, when the blood is spotted at a position away from the filter paper (4), the blood smoothly diffuses and is a diffusion limiting film.
Although it may not be possible to lead it to (3), if blood is spotted near the filter paper (4), the blood can be smoothly led to the diffusion limiting membrane (3), and also spotted. Since it is extremely easy to set the locations as described above, there is no particular inconvenience.

FIG. 7 is a plan view showing a main part of another configuration of the blood glucose level measuring device, FIG. 8 is a longitudinal sectional view, and the difference from the blood glucose level measuring device shown in FIG. 3 and FIG. (11), through hole
It is only that a pair of minute upward projections (15) are provided on the front side of (10) and that a taper surface is formed on the lower surface of the projection (12b) on the thin plate introduction side.

Therefore, the blood glucose level measuring device having this configuration has a diffusion limiting film.
When mounting (3), it is sufficient to slide the thin plate (1) in while it is engaged with the accommodation groove (11) and push it in.
Go over the through hole (10) with the tip of (1) being guided slightly upward. Then, the tip of the thin plate (1), which has passed over the through hole (10), is guided by the tapered surface of the protrusion (12b) and guided downward. As a result, even if the thin plate (1) is warped to some extent, the through hole
It will be guided to the engaging portion (12) without hitting the inner wall of (10).

As is clear from the above description, the diffusion limiting film (3) can be used without any inconvenience even if the thin plate (1) to which the diffusion limiting film (3) is attached has some warp. The yield of the holder will be improved. Also, thin plate
Since the tip of (1) is guided upward, there is no possibility of rubbing the surface of the enzyme electrode (8), and deterioration of the immobilized enzyme membrane due to rubbing can be prevented.

Further, in the above-mentioned blood glucose level measuring device, although it is not possible to regulate the upward movement of the thin plate (1), the storage groove (1
If a regulating member (not shown) is provided on top of 1), the thin plate (1)
It is even more preferable that the upward movement of the can be regulated.

<Embodiment 3> FIG. 9 is a longitudinal sectional view showing still another embodiment.
The difference from the embodiment shown in FIG. 2 and FIG. 2 is that the filter paper (4) has the same planar shape as the opening (2) and
Only (4) is accommodated in the opening (2), and the other parts have the same configuration.

Therefore, in the case of this embodiment, the thickness of the diffusion limiting film holder is equal to the thickness of the filter paper (4) as compared with the thickness of the diffusion limiting film holder in the embodiment of FIGS. 1 and 2. The blood was thinned, and the spotted blood (14) was used as in the above example.
Can be positively guided to the diffusion limiting film (3).

Incidentally, the present invention is not limited to the above embodiment, for example, the shape of the thin plate (1) can be appropriately changed to correspond to the blood glucose level measuring device, and the shape of the permeable membrane can be changed. It can be set as desired
By forming a radial groove centered on the opening (2) on the surface of (1), it is possible to more smoothly guide the blood to the diffusion limiting film (3), and any other than blood It can be applied to a diffusion limiting membrane holder for measuring the concentration of a specific substance contained in the test solution of 1. Is possible.

<Effects of the Invention> As described above, the first invention is that the permeable membrane positively inhales the test solution when the test solution dropped on the thin plate is in a state of touching the permeable membrane even a little. Since most of the dropped test solution can be guided to the diffusion limiting film, there is no need to increase the positional accuracy when dropping the test solution, and the workability for concentration measurement can be significantly improved. There is a unique practical effect.

The second invention can significantly reduce the amount of the test solution remaining on the thin plate when the dropping position is displaced,
Compared with the case where the surface of the thin plate has hydrophilicity, it has a practicable peculiar practical effect that the increase amount of the test solution can be significantly suppressed.

The third idea is that the amount of the test solution contained in the permeable membrane can be suppressed to a necessary minimum, so that a specific practical effect that the increased amount of the test solution can be further suppressed. Play.

Since the fourth solution is more positively sucked in, the test solution has a unique practical effect that the dropped test solution can be guided to the diffusion limiting film more reliably.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the diffusion limiting film holder of the present invention, FIG. 2 is a vertical sectional view, FIG. 3 is a plan view showing a main part of a blood glucose level measuring device, and FIG. 4 is a vertical section. FIG. 5 is a plan view showing the mounting operation, FIG. 6 is a plan view showing another embodiment of the diffusion limiting film holder, and FIG. 7 is a main part of another configuration of the blood glucose level measuring device. FIG. 8 is a plan view, FIG. 8 is a vertical cross-sectional view, and FIG. 9 is a vertical cross-sectional view showing still another embodiment of the diffusion limiting film holder. (1) …… thin plate, (2) …… opening, (3) …… diffusion limiting film, (4) …… filter paper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Yamazaki, Inventor, 1000 Otani, Otani, Okamoto-cho, Kusatsu, Shiga Prefecture 2 Daikin Industry Co., Ltd. Shiga Factory (72) Yasuhiro Nagata Inventor, Otani, Okamoto-cho, Kusatsu, Shiga Prefecture No. 2 Shiga Works of Daikin Industries, Ltd.

Claims (4)

[Scope of utility model registration request] 1. An opening (2) for passing a test solution is formed at a predetermined position of a thin plate (1) having a predetermined shape, and diffused on one side surface of the thin plate (1) so as to cover the opening (2). A limiting film (3) is attached, and moreover, between the thin plate (1) and the diffusion limiting film (3),
A diffusion limiting membrane holder characterized in that a permeable membrane (4) covering at least a part of the opening (2) is attached. 2. The diffusion limiting film holder according to claim 1, wherein the surface of the thin plate (1) has water repellency. 3. The permeable membrane (4) is a narrow membrane, and
The diffusion limiting film holder according to claim 1 or 2, which is attached so as to match the center of the opening (2). 4. The diffusion limiting membrane holder according to any one of claims 1 to 3, wherein the permeable membrane (4) is hydrophilized.