JP2713264B2 - Leachate suction device and its collection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leachate suction apparatus for collecting a small amount of leachate, which is an interstitial liquid, from the surface of a living body and a method for collecting the same.

[0002]

2. Description of the Related Art Conventionally, glucose concentration in a living body, lactic acid,
The continuous measurement of the concentration of a chemical substance such as urea nitrogen was generally performed by collecting blood. These measure the concentration using a biosensor equipped with an immobilized enzyme membrane electrode,
The biosensor has the feature that it can be measured with high sensitivity with a small amount of sample because it can be small in size. Therefore,
These measuring devices and measuring methods can be used in the fields of medicine, diagnosis and biochemistry, for example, for diagnosing diseases by measuring the concentration of organic components contained in blood, urine and the like. However, there is a problem that it is not possible to eliminate physical and mental pains such as infection, blood loss, etc. due to the pain of the patient involved in blood collection and the labor on the medical side.

Recently, as a method for solving these problems, a stratum corneum of the skin is locally removed, an interstitial fluid is extracted from the portion instead of blood, and the exudate is used as a sensor to measure the concentration of components in the body. A way was developed. One such method is disclosed in Japanese Patent Application Laid-Open No. 4-341241.

FIG. 4 is a sectional view showing an example of a conventional leachate suction device. As shown in FIG. 4, the leachate suction device has a suction cell body 20 having a suction port 21 at one end and an opening 24 at the other end, and a mesh portion 22 fitted into the opening 24 and fixed by a frame 23. It is composed of Then, when collecting interstitial fluid, first, the mesh portion 22 is brought into contact with the skin surface from which the stratum corneum has been peeled off, the end of the suction cell body 20 is brought into close contact with the skin portion, the air is exhausted from the suction port 21, and the internal space is depressurized. And
The interstitial fluid, leachate, was collected by suction.

[0005]

In the above-mentioned conventional leachate suction device, since the leachate is sucked through the mesh portion 22, the suction path is closed when the small holes of the mesh portion 22 are filled with the leachate. As a result, it becomes impossible to leaching smoothly and continuously. As a result, there is a problem that much time is required to obtain the required leachate, and the efficiency of collecting the leachate is poor.

For example, if the pressure of the suction port 21 is reduced to about 0.5 atm, the skin surface is first reduced to 0.5 atm, so that the exudate is sucked from the skin surface. However, the exudate is gradually sucked and fills the mesh portion 22. Further, the skin surface is soft and swells, and adheres to the mesh portion 22. As a result, the suction system is closed even if suction is always performed under reduced pressure from the suction port 21, and the exhaust resistance increases. Since the pressure on the skin surface rises to a value close to 1 atm, the leaching of the exudate from the skin surface becomes extremely slow. In addition, sealing failure occurs between the skin surface of the suction cell body 20 and leakage occurs, air bubbles are mixed in the leachate, and the apparent collection amount increases, but the dilution ratio becomes non-uniform when diluted and measured. There was a problem. Insufficient time, such as blood glucose load test or measurement of diurnal fluctuations, in which the sampling time is fixed, or the enzyme reaction is not constant due to the effects of air bubbles, and the amount of leachate is insufficient, resulting in poor measurement accuracy. was there.

It is an object of the present invention to provide a leachate suction apparatus and a leachate suction method capable of efficiently sucking and collecting leachate without adversely affecting the measurement accuracy of a biochemical substance concentration such as a blood sugar level.

[0008]

A first feature of the present invention is as follows.
An external suction cell having, at one end, a first suction port for suction and pressure reduction to infiltrate the exudate from the body surface, and having a first opening at the other end facing the body surface, A second suction port, which is provided in the first opening and has a second suction port for suction and pressure reduction for extracting the exudate at one end, and is fitted to the second opening facing the living body surface at the other end; An internal suction cell comprising an extraction plate member having a plurality of extraction ports in direct contact with the body surface, and the external suction cell,
A leaching solution suction device including a variable means capable of sliding the internal suction cell up and down.

The extraction plate member may be a mesh member fixed by a frame, a perforated plate member having a plurality of through holes formed in a metal or resin plate, or a porous plate member. A multi-needle plate member having a plurality of extraction holes formed therein, or a plurality of flow grooves extending radially outward from the center and penetrating through a surface that is disposed in these flow grooves and directly contacts the biological surface. A plate member having a plurality of the extraction ports, and a reinforcing plate member having a plurality of tunnel-shaped flow paths that cover the flow path grooves and have a flow path communicating with the second suction port are formed. It is characterized by:

Further, the outer periphery of the second suction port member and the external suction cell are supported by a seal member.

A second feature of the present invention is that in the leachate collecting method of the leachate suction device, the step of sucking the first suction port and the step of reducing the suction pressure of the first suction port for a certain period of time are performed within the external suction cell. Holding the reduced pressure, and pressing the internal suction cell against the surface of the living body while holding or interrupting the reduced suction pressure of the first suction port,
A step of sucking the second suction port and depressurizing the inside of the internal suction cell; a step of depressurizing the second suction port for a certain period to extract a leachate; and separating the internal suction cell from the surface of the living body Is included at least once.

After the step of reducing the pressure of the first suction port for a certain period of time and maintaining the inside of the external suction cell under reduced pressure, a gas is supplied or leaked from the first suction port to substantially increase the pressure. It is characterized by including a step of returning to atmospheric pressure.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

1 (a) and 1 (b) are a sectional view (a) showing a first embodiment of a leachate suction device of the present invention and a timing chart (b) for explaining the operation.
As shown in FIG. 1 (a), this leachate suction device is provided with a first suction port 2 and a first opening 3 in an external suction cell 1, and in the first opening 3, Is the internal suction cell 4
Is decorated.

Further, a second end of the internal suction cell 4
A mesh portion 7 that is in direct contact with the surface of the living body is fitted into the opening 6 without any gap, and a second suction port 5 is provided at the other end. The mesh part 7 is formed by supporting a mesh made of nylon on a frame 8.

The outer periphery of the second suction port 5 is supported by the external suction cell 1 with a seal member. Here, a silicone O-ring 9 is used, and the internal suction cell 4 has a structure in which the internal suction cell 4 can be freely slid up and down manually with respect to the external suction cell 1.

The first suction port 2 and the second suction port 5 are provided with first and second on-off valves 10 and 11, respectively.
Independent vacuum suction, vacuum interruption, opening, closing, etc. can be performed.

The exudate suction device having such a structure is first placed on the skin surface from which the stratum corneum has been removed. Then, the internal suction cell 4 is raised while the second opening / closing valve 11 is closed, and the first opening / closing valve 10 is provided.

For example, when the pressure is reduced to about 0.5 atm, the first
The space between the opening 3 and the skin surface is maintained at 0.5 atm. The leach rate of the leachate is usually 0.2 μl for healthy subjects
/ Min / cm ² , 10 μl is a required amount, and 10 m if the external suction cell 1 has a diameter of 1.5 cm.
The required amount is reached below in.

Next, the first on-off valve 10 is closed, and the pressure reduction of the external suction cell 1 is interrupted.
And press the mesh portion 7 against the skin surface. At this time, the leachate permeates the mesh part 7.

Next, the second on-off valve 11 is opened, and the leachate is extracted from the second suction port 5. Since the leachate has previously penetrated into the mesh portion 7, the suction time is 2 minutes if the suction pressure is equal to the pressure of the external suction cell 1 or slightly maintained at a negative pressure.
It is completed in about At this time, the first on-off valve 10 may be opened to introduce air, or a gas such as N ₂ may be introduced.

After complete extraction, the second on-off valve 11
Is closed, and the internal suction cell 4 is raised. By repeatedly leaching the leachate and extracting the leachate based on such a process, an intermittent leachate for continuously measuring the chemical concentration component of the leachate can be obtained.

When the external suction cell 1 is performing suction under reduced pressure, the skin surface rises and lightly contacts the mesh portion 7 fitted in the second opening 6 of the internal suction cell 4. At this time, since the suction pressure is not reduced in the second opening 6 yet, the skin surface in the external suction cell 1 is maintained at 0.5 atm and the skin surface does not stick to the mesh portion 7. . The suction by the external suction cell 1 is not prevented, and the leaching of the leaching solution is continued. Conversely, if the skin surface rises too much, subcutaneous bleeding may occur. However, the bleeding is suppressed by pressing with the mesh portion 7.

The inner diameter of the first opening 3 of the external suction cell 1 may be any range as long as it is freely movable with respect to the outer diameter of the internal suction cell 4, for example, a clearance of about 1 mm is sufficient. Yes, and can be easily moved manually. Further, the stroke of the mesh portion 7 during the vacuum suction by the external suction cell 1 is 1 mm for the above-described reason.
The degree was appropriate.

In such a leachate suction apparatus, first, suction and extraction of leachate are performed in separate steps,
It is always possible to leach the leachate at a constant leach rate. Therefore, the reduced pressure suction is reliably held between the external suction cell 1 and the skin surface, and no accident such as leakage occurs.

Even when the leachate is diluted and measured at a constant dilution ratio, the sampling time is reduced, and stable and accurate measurement can be performed. Conventionally, the flow path is not blocked by the exudate or the swelling of the skin as in the case where suction and extraction of the exudate from the skin surface are simultaneously performed through a nylon mesh. This has the advantage that the efficiency of exudate collection is improved and measurement can be performed with reduced physical and mental burden on the patient.

FIG. 2 is a sectional view showing a second embodiment of the leachate suction device of the present invention. This leachate suction device,
As shown in FIG. 3, instead of the mesh portion 7 in the above-described embodiment, a plurality of flow grooves 15 extending radially or concentrically outward from the center, and surfaces arranged in these flow grooves 15. A stainless steel spacer 17 having a plurality of extraction ports 16 penetrating therethrough, a reinforcing plate 18 having a flow path port 19 communicating with the second suction port 5 while forming a plurality of tunnel-shaped flow paths covering the flow path groove 15. Thus, a leachate extraction plate member is provided. Otherwise, the configuration is the same as the above-described embodiment.

In the leaching solution suction device having such a structure, the effect shown in the above embodiment can be obtained in the same manner, and the thickness of the spacer 17 can be reduced to about 0.1 mm, so that the second opening The retention volume of the leachate in the part 6 can be reduced to 20 μl or less. In the mesh unit 7 of the above-described embodiment, 10
Although it has a large volume of about 0 μl, there is an advantage that the recovery rate of the leachate is increased by a remarkably small amount.

The material of the mesh portion 7 of FIG. 1 and the spacer 17 of FIG. 2 have been described as being limited to nylon mesh and stainless steel.
For example, nickel, a polymer material, or an injection molding material may be used.
In any case, the formation of the extraction port 16, the flow channel 15, and the like can be realized at a low price because the mass production is relatively easy.

Further, such a leachate extraction plate member having another structure can be used. For example, a perforated plate provided with a plurality of fine through holes having a diameter of 0.1 mm or less in a mere metal or resin plate, a porous material using a material such as nonwoven fabric or porous sintered ceramic having a thickness of about 0.1 mm. A similar effect can be obtained with an extraction plate member such as a thin plate.

Further, similar results can be obtained with an extraction plate member such as a multi-needle plate having a large number of fine needles having a length and a diameter of 0.1 mm or less and a plurality of through-holes, and without removing the stratum corneum. The exudate can be efficiently collected from the skin surface.

[0032]

As described above, the present invention relates to a double-structured suction cell in which an internal suction cell is provided inside an external suction cell,
By alternately performing the steps of sucking the leachate with the external suction cell and extracting the leachate with the internal suction cell, the leachate in the leachate extraction member that has been leached can be efficiently sent to the suction port side, and reduced pressure suction is performed. There is an effect that the leaching solution can be collected at a constant leaching speed during medium. In addition, in the case where the in-vivo component concentration of the exudate is continuously measured, there is an effect that the component concentration of the exudate can be measured accurately in a short time.

In the embodiment of the present invention, the external suction cell and the internal suction cell are circular. However, the present invention is not limited to this, and other shapes such as a rectangular shape may be used.

[Brief description of the drawings]

FIG. 1 is a sectional view (a) showing a first embodiment of a leachate suction device of the present invention, and a timing chart (b) for explaining the operation.

FIG. 2 is a sectional view showing a second embodiment of the leachate suction device of the present invention.

FIG. 3 is a plan view showing an example of a leachate extracting member of the leachate suction device of FIG. 2;

FIG. 4 is a cross-sectional view showing an example of a conventional leachate suction device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 External suction cell 2 1st suction port 3 1st opening 4 Internal suction cell 5 2nd suction port 6 2nd opening 7,22 mesh part 8,23 frame 9 O-ring 10 1st opening / closing valve DESCRIPTION OF SYMBOLS 11 2nd on-off valve 15 Channel groove 16 Extraction port 17 Spacer 18 Reinforcement board 19 Channel port 20 Suction cell main body 21 Suction port 24 Opening

Claims (9)

(57) [Claims] 1. An external suction cell having a first suction port at one end for suction and decompression for leaching an exudate from a living body surface and having a first opening at the other end facing the living body surface,
A second opening, which is provided in the first opening of the external suction cell and has a second suction port at one end for suction and pressure reduction for extracting the leachate, and a second opening facing the living body surface at the other end. And an internal suction cell composed of an extraction plate member having a plurality of extraction ports in direct contact with the surface of the living body, and a variable slide of the internal suction cell up and down with respect to the external suction cell. And a means for sucking out leachate. 2. The leachate suction device according to claim 1, wherein the extraction plate member is a mesh member fixed by a frame. 3. The leachate suction device according to claim 1, wherein the extraction plate member is a perforated plate member having a plurality of through holes formed in a metal or resin plate. 4. The leachate suction device according to claim 1, wherein the extraction plate member is a porous plate member. 5. The leachate suction device according to claim 1, wherein the extraction plate member is a multi-needle plate member having a plurality of extraction holes formed therein. 6. The extraction plate member includes a plurality of flow channels extending radially outward from a center and a plurality of the extraction ports disposed in the flow channels and penetrating a surface directly contacting the surface of the living body. And a reinforcing plate member that covers the flow channel groove, forms a plurality of tunnel-shaped flow channels, and has a flow channel communicating with the second suction port. Item 6. The leachate suction device according to Item 1. 7. The leachate suction device according to claim 1, wherein the outer circumference of the second suction port member and the external suction cell are supported by a seal member. 8. The method for collecting leachate of a leachate suction device according to claim 1, wherein the step of sucking the first suction port and the step of reducing the pressure of the first suction port for a certain period of time perform the inside of the external suction cell. Depressurizing and holding, pressing and holding the internal suction cell against the living body surface while holding or interrupting the suction pressure of the first suction port, and suctioning the second suction port to perform the internal suction. Depressurizing the inside of the cell, depressurizing the second suction port for a certain period to extract the exudate, and raising the internal suction cell so as to separate it from the surface of the living body at least once. Characterized leachate collection method. 9. After the step of reducing the pressure of the first suction port for a certain period of time and maintaining the inside of the external suction cell under reduced pressure, a gas is supplied or leaked from the first suction port to substantially increase the pressure. 9. The method of claim 8, further comprising the step of returning to atmospheric pressure.