JPH09140687A - Aspirator for exudate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extract an exudate without changing the original concentrations of the biochemical components by using a simple means comprising obliquely formed plural projecting needles on the opening side of an extracting plate member and plural through holes inside of or adjacently to the projecting needles. SOLUTION: First, hollow needles 5 are penetrated into corneal layers of epidermis by actions of pressing a suction device onto skin surface and reduced pressure by exhausting from a suction opening 1. Then the force for extending the skin flatly is generated by injecting the needles because the needles 5 are oblique to the skin face, the elasticity of the skin is reduce by extension of the skin and therefore the resistance of the corneal layer against injection is reduced. The needles can be smoothly passed through the corneal layer. The needles are not clogged at the hollow part because the needles 5 are injected under pushing through the skin. The interstitial fluid at the skin is extracted as an exudate through the hollow needles 5 and introduced to the path way as a gap between a suction cell 3 and a path way plate 4 and extracted outside from the suction opening 1 by suction pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leachate suction device for sucking and collecting leachate in a living body, and more particularly to a leachate suction device used for collecting a small amount of interstitial liquid leachate from the surface of a living body.

[0002]

2. Description of the Related Art Conventionally, measurement of the concentration of chemical substances such as glucose, lactic acid, and urea nitrogen in a living body has generally been performed by collecting blood. The concentration of each component is determined by the color change of the test paper, the absorbance, the electrical signal converted by the biosensor,
It is measured by such as. These measuring methods have been improved day by day, and in recent years, it has become possible to measure a very small sample of several μl.

[0003] Normally, blood is collected by puncturing a vein such as an arm with a blood collection needle, but when the blood required for measurement is only a few µl, a fine needle having an inner diameter of several tens of µm is inserted into a capillary. It is also possible to do. According to this method, it is possible to reduce physical pain and fear caused by the needle puncture that the patient receives. However, since the capillaries are extremely thin, it is not easy to accurately position them and insert the needle. Therefore, a method using a blood collection device provided with a large number of fine hollow needles has been proposed. This method eliminates the need for positioning. Such a method is disclosed in, for example,
132119.

FIG. 9 is a schematic sectional view showing the blood collecting apparatus. A large number of through holes 102 having a diameter of 10 to 50 μm are provided in the first silicon substrate 101, and a film thickness of 1 including the inner wall of the through hole 102 is formed on the back surface of the first silicon substrate 101.
A silicon nitride film 104 of about μm is formed. The silicon nitride film 104 on the inner wall surface of the through-hole 102 is further extended outside from the surface of the first silicon substrate 101 to form a hollow needle 103. On the back surface of the first silicon substrate 101, a second silicon substrate 10
6 are joined. The central portion of the second silicon substrate 106 is a thin membrane 107,
A cavity 108 is formed on the back side. Membrane 1
07, an Au film 109 is provided, and a micro heater 110 is further provided thereon. Blood collection by this blood collection device is performed as follows. First, the hollow needle 103 is pushed into the skin surface. Next, heat is generated in the micro heater 110. At this time, since the expansion coefficients of Au and silicon are different, the membrane 107 is deformed so that the cavity 108 expands, and a negative pressure is generated inside the cavity 108 and the hollow needle 103. Blood is collected by this negative pressure.

[0005] On the other hand, there has been proposed a method in which a subcutaneous tissue fluid is collected instead of blood to measure a chemical component in a living body. In this method, only the stratum corneum on the skin surface is removed, and the target chemical component in the living body is measured using a tissue fluid obtained by aspirating the site under reduced pressure (hereinafter referred to as a suction exudate or exudate). is there. This method is disclosed, for example, in JP-A-4-341241. Hereinafter, this method will be described with reference to the drawings.

FIG. 10 is a sectional view showing an example of a conventional leachate suction device. This leachate suction device has a suction port 2 at one end.
01 and the opening 202 at the other end.
3 and a mesh part 206 fitted in the opening 202 and fixed by the frame 205. Collection of leachate by this device is performed as follows. First, only the stratum corneum of the skin where the exudate is to be collected is removed.
Next, the mesh part 206 is brought into contact with the skin surface from which the stratum corneum has been peeled off, and the end of the suction cell body 203 is further brought into close contact with the skin surface. Then, it is exhausted from the suction port 201 by a pump or the like to reduce the pressure in the internal space. The exudate leaches out of the skin surface due to the reduced pressure, and is taken out of the suction cell body 203 via the inlet 204.

[0007]

In the conventional blood collection apparatus shown in FIG. 9, the hollow needle 103 is formed of a silicon nitride film. However, silicon nitride having a thickness of 1 μm is very brittle and breaks through the stratum corneum of the skin. However, it was difficult for the needle tip to reach the capillaries. In addition, even when the blood reaches the capillaries, there is a very high risk that the holes will be bent halfway and the holes will be closed, and broken pieces of the hollow needle will be left in the body. Worse, the blood has a diameter of 10-20.
Although red blood cells of about μm are present, when blood is passed through a capillary of several tens of μm, a phenomenon called so-called hemolysis in which the red blood cells are destroyed occurs, and there is a problem that blood components are changed.

On the other hand, the conventional method for measuring a suction leachate shown in FIG. 10 completely solves the above-mentioned problems of the blood collecting apparatus, but has the following problems. In this method, the stratum corneum must be removed before the suction. Usually, the stratum corneum is removed by tape stripping, but it takes about 30 minutes to completely remove the stratum corneum. Moreover, the thickness of the stratum corneum and how to remove it vary depending on gender, site, age, etc., and the practitioner must always work carefully and carefully. If the removal of the stratum corneum is inadequate, the efficiency of exudate collection will be significantly reduced, making it impossible to measure.On the other hand, if it is too alive to remove not only the stratum corneum but also the dermis, it will bleed and become painful. Can also cause skin infections. The quality of the removal depends solely on the skill of the operator, which has prevented this method from being widely used. In addition, the patient had to stay still during the removal of the stratum corneum, which was a heavy physical and mental burden.

An object of the present invention is to provide a leachate aspirating apparatus which can easily collect leachate without changing the original concentration of biochemical substances.

[0010]

SUMMARY OF THE INVENTION A feature of the present invention is that a suction cell has a suction port at one end for sucking and depressurizing a leachate from a living body surface and an opening at the other end facing the living body surface. And an extraction plate member that is fitted or adhered to the opening of the suction cell, directly contacts the surface of the living body, and extracts the leachate. A plurality of projection needles are formed obliquely to the vertical direction of the plate surface of the extraction plate member, and a plurality of through holes are formed in the projection needle or adjacent to the projection needle. It is that you are.

[0011] Preferably, a means for extending the skin in a direction opposite to the inclination of the protruding needle is provided. Further, it is desirable that the length of the protruding needle is in the range of 10 μm to 300 μm and that the inclination of the needle is 15 ° to 45 ° with respect to the vertical direction of the extraction plate member plate surface.

Preferably, the plurality of flow grooves are formed radially or radially and concentrically. Further, it is preferable that an auxiliary plate that covers the entire upper surface of the flow path plate and has a liquid feed hole corresponding to the suction port is placed. On the other hand, the material of the flow path plate is desirably a metal material, a resin material, or a semiconductor which does not elute with the leaching solution.

[0013]

Next, the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a cross-sectional view showing a first embodiment of a leachate suction device of the present invention, and FIG. 2 is a perspective view of a flow path plate installed in the leachate collection device. is there.

As shown in FIG. 1, a suction cell body 3 having a suction port 1 for sucking and depressurizing the leachate from the skin surface and an opening 2 on a surface side directly in contact with the skin surface.
And a channel plate 4 fitted and fixed in the opening 2 and directly in contact with the skin. The channel plate 4 is composed of hollow needles 5 that are obliquely aligned with respect to the vertical direction of the plate surface, and a resin 6 that holds and fixes the hollow needles. The material of the hollow needle 5 must be chemically stable so that interfering substances do not elute into the leachate. For a metal, stainless steel or nickel is preferable, and for a polymer material, polypropylene or Teflon is preferable. Further, as the resin 6, an epoxy resin, an ultraviolet curable resin, or the like can be used. The size of the channel plate 4 needs to be selected so as to be in close contact with the curved surface of the skin and to obtain the amount of exudate necessary for the measurement, and the outer diameter is preferably about 10 to 30 mm.

FIG. 2 is a perspective view of the flow path plate 4 of this embodiment. The hollow needles 5 are obliquely arranged in a plate-shaped resin 6. The height of the hollow needle 5 from the plate surface must be selected so that it penetrates the stratum corneum and does not reach the dermis. If the length is too short, the exudate cannot be collected, and if the length is too long, bleeding occurs and components such as blood cells are mixed, and worse, the hollow needle 5 is clogged by coagulation. The thickness of the stratum corneum of a human varies depending on the site, but is 20 to 30 μm inside the forearm where normal sampling is performed. The depth of the outermost layer of the dermis is 60 to 70 μm. Therefore, it is preferable that the height of the tip of the hollow needle 5 from the flow path plate 4 is about 50 μm. Further, the thickness of the hollow needle 5 must be selected so as not to give a patient a feeling of pain or fear, and the outer diameter should be 0.2 to 1.0 m.
m is desirable. Next, regarding the number of needles, when using fine needles having an outer diameter of 1 mm or less, it is desirable to set the number to 100 or more. This is because the amount of exudate to be collected is extremely small, about 0.01 μl / min per hollow needle 5. Next, the inclination of the hollow needle 5 will be described.
Is preferably set to 15 to 75 ° with respect to the vertical line of the flow path plate 4. Further, the tip angle of the hollow needle 5 is preferably set to 15 to 45 ° as in a normal syringe. The thickness of the flow path plate 4 is preferably as small as possible in order to reduce the amount of liquid remaining in the flow path plate 4, but is preferably about 1 to 5 mm in order to impart strength.

Next, a mechanism from when the suction cell body 3 is attached to the skin surface until when the exudate is collected will be described. First,
The hollow needle 5 penetrates into the stratum corneum due to the pressing force for bringing the suction device into close contact with the skin surface and the pressure reduction by exhaustion from the suction port 1. In the exudate suction device according to the present invention, the hollow needle 5 faces obliquely to the vertical line of the skin surface. For this reason, when the hollow needle 5 is pushed in, a force for extending the skin in the horizontal direction is generated. Because the skin is stretched by this force, the elasticity of the skin decreases. Further, since the puncture resistance of the keratin is reduced, the hollow needle 5 can easily penetrate the keratin.
Further, since the hollow needle 5 enters while the tip of the needle pushes the skin to the left and right, the needle hole is not clogged. Then, the interstitial fluid in the skin passes through the hollow needle 5 to be exuded as an exudate. The leachate that has entered the flow path 7, which is a gap between the suction cell body 3 and the flow path plate 4, is taken out of the suction cell body 3 via the suction port 1 by suction pressure.

FIGS. 3A to 3E are schematic sectional views showing an example of a method of manufacturing the flow path plate 4. FIG. First, the thickness 0.0
Place a 5 mm sheet 8 on a flat, hard surface. Next, a frame 9 having a plurality of through holes 10 on the upper surface is fixed on the sheet 8. Then, the hollow needles 5 are sequentially inserted from the through hole 10 at a predetermined angle. (FIG. 3A) Next, the injection device 1 such as a dispenser is inserted from the injection port 11.
2 is used to inject a liquid resin 6 to fill the inside of the frame body 9. (FIG. 3B) Next, the resin 6 is cured. An epoxy resin may be left at room temperature for about 30 minutes. (FIG. 3C) When the resin 6 is cured, the sheet 8 and the frame 9 are taken out. (FIG. 3D) Next, the upper surface is cut so that the resin 6 has a desired thickness, and the flow path plate 4 is completed. (FIG. 3E) FIGS. 4A and 4B are schematic views showing a structural example of the frame 9 used here. The frame 9 of (a) is a type in which the hollow needles 5 are inserted one by one into the through hole 10 and the positioning accuracy of the hollow needles 5 is good, and the frame 9 of (b) has a plurality of hollow needles 5 in the through hole 10.
It is an advantage that the hollow needles 5 can be arranged at a high density with the type of inserting the hollow needles. Teflon or the like having no adhesiveness to the resin 6 is preferably used for these frames 9.

In this embodiment, the hollow needle 5 and the resin 6
Although the flow path plate 4 was formed using the method described above, the manufacturing method is not limited to this, and may be integrally formed using a resin or the like, or may be integrally formed by processing a semiconductor substrate such as silicon. Good.

(Embodiment 2) FIG. 5 is a schematic sectional view showing a second embodiment of the present invention. The channel plate 4 of this embodiment has a structure in which hollow needles 5 and hollow tubes 13 are alternately arranged. The distal end of the hollow tube 13 is flush with the skin contact surface of the flow path plate 4, and the distal end of the hollow needle 5 projects slightly beyond this. The protrusion amount is the same as that of the first embodiment, and may be, for example, 50 μm. The mechanism by which the channel plate 4 punctures the stratum corneum will be described. When this device is attached to the skin and sucked through the suction port 1, the channel plate 4 comes into close contact with the skin surface by the pressing force and the suction. At this time, since the hollow tube 13 pulls the skin in the vicinity of the hollow needle 5 upward, the hollow needle 5 can very easily puncture the keratin. The flow channel plate 4 of the present embodiment can be manufactured by the same method as that of the first embodiment.

(Embodiment 3) FIG. 6 is a schematic sectional view showing a third embodiment of the present invention. In the flow channel plate 4 of the present embodiment, some hollow needles 5 are inclined in a certain direction, and other hollow needles 5 are inclined in the opposite direction. When the exudate suction device is brought into close contact with the skin, the hollow needles 5 facing in opposite directions to each other.
Causes the skin surface to stretch to both sides. For this reason, it is possible to puncture the keratin more easily than when the hollow needles 5 are inclined and aligned in one direction.

(Embodiment 4) FIG. 7 is a schematic sectional view showing a fourth embodiment of the present invention. The channel plate 4 of the present embodiment includes a plurality of hollow needles 5 inclined in one direction and a protruding needle 14 perpendicular to the skin mounting surface. The protrusion amount of the tip of the projection needle 14 is the same as or slightly longer than that of the hollow needle 5. The tip angle of the projection needle 14 is preferably set to 30 to 45 degrees. When the channel plate 4 is mounted on the skin, the protruding needles 14 enter the stratum corneum and fix the surrounding stratum corneum. For this reason, the force to extend the skin that acts when the hollow needle 5 enters the stratum corneum increases, and the hollow needle 5 can easily penetrate the stratum corneum. Further, the flow path plate 4 of the present embodiment has an advantage that it is easy to manufacture.

(Embodiment 5) FIGS. 8A to 8C are schematic sectional views showing a fifth embodiment of the present invention. The leachate suction device of the present embodiment has a mechanism for extending the skin from the outside of the cell body to the side opposite to the inclination of the hollow needle 5. (A)
(C) are specific examples thereof.

The suction device shown in FIG. 8A includes a spring member 15 connected to the suction cell body 3, an elastic member 16 connected to the tip of the spring member 15, and the flow path plate 4. Elastic body 16
Is made of rubber or the like having a large coefficient of friction with the skin, and the lower surface thereof is positioned below the hollow needle 5. When the suction cell body 3 is brought into close contact with the skin, the elastic body 16 stretches the skin in a direction away from the suction cell body 3 by the action of the spring material 15, that is, in a direction opposite to the inclination of the hollow needle 5. Therefore, the hollow needle 5 can easily penetrate the stratum corneum. The means for stretching the skin need not be the elastic body 16. One example is (b), in which a file-like metal plate 17 is attached instead of the elastic body 16. Further, in the device shown in (c), a rotatable roller 18 made of rubber or the like is provided outside the suction cell body 3. A method of collecting leachate by this apparatus will be described. First, the suction cell body 3 is brought into close contact with the skin, and the roller 18 is brought into contact with the skin. Next, the roller 18 is rotated several tens of degrees counterclockwise in the drawing to stretch the skin. Next, a space between the hook 19 provided on the suction cell body 3 and the hook 20 provided on the roller 18 is fixed by a cord body 21. When the pressure is reduced from the suction port 1 in this state, the hollow needle 5 easily penetrates the stratum corneum,
The tip of the hollow needle 5 reaches the epidermis layer. The exudate leached from the skin layer is taken out of the suction cell body 3 through the inside of the hollow needle 5 by suction pressure.

[0025]

As described above, according to the present invention, the exudate can be easily collected without damaging the blood vessel or removing the stratum corneum which was conventionally required. Therefore, the subject does not need to feel any pain when measuring the blood sugar level and other body fluid components. As a result, healthy people who are reluctant to take the test or those who are suspected of having the disease will be able to receive the test without resistance, enabling prevention and early detection of the disease and improving the health of the entire nation. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of a leachate suction device of the present invention.

FIG. 2 is a perspective view showing a flow channel plate used in the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a method of manufacturing the flow channel plate of FIG.

4 is a schematic perspective view of a frame body used for manufacturing the flow channel plate of FIG.

FIG. 5 is a schematic sectional view showing a second embodiment of the leachate suction device of the present invention.

FIG. 6 is a schematic sectional view showing a third embodiment of a leachate suction device of the present invention.

FIG. 7 is a schematic sectional view showing a fourth embodiment of the leachate suction device of the present invention.

FIG. 8 is a schematic sectional view showing a fifth embodiment of the leachate suction device of the present invention.

FIG. 9 is a schematic cross-sectional view of a conventional blood collection device using a fine needle.

FIG. 10 is a schematic sectional view showing a conventional leachate collecting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suction port 2 Opening 3 Suction cell body 4 Flow path plate 5 Hollow needle 6 Resin 7 Flow path 8 Sheet 9 Frame body 10 Through hole 11 Injection port 12 Injection device 13 Hollow tube 14 Projection needle 15 Spring material 16 Elastic body 17 Metal plate 18 Roller 19 Hook 20 Hook 21 String body 101 First silicon substrate 102 Through hole 103 Hollow needle 104 Silicon nitride film 105 Bonding layer 106 Second silicon substrate 107 Membrane 108 Cavity 109 Au 110 Micro heater 201 Suction port 202 Opening 203 Suction cell body 204 Inlet 205 Frame 206 Mesh

Claims (11)

[Claims] 1. A suction cell body having at one end a suction port for sucking and decompressing a leachate from the surface of a living body and having an opening facing the body surface at the other end, and the opening of the suction cell body. In an exudate suction device having an extraction plate member that is adhered or fitted to a portion, directly contacts the living body surface, and extracts the exudate, a plate surface of the extraction plate member on the opening side of the extraction plate member Diagonally to the vertical direction of
A leachate suction device comprising: a plurality of projection needles; and a plurality of through holes formed in or adjacent to the projection needle. 2. The leachate suction device according to claim 1, wherein the plurality of projection needles are inclined in the same direction. 3. The leachate suction device according to claim 1, wherein a part of the plurality of projection needles is inclined in one direction and the other part is inclined in a different direction. 4. The leachate suction device according to claim 1, wherein the inclination of the projection needle is 15 ° to 45 ° with respect to the vertical direction of the extraction plate member plate surface. 5. The length of the projection needle is from 10 μm to 300 μm.
2. The leachate suction device according to claim 1, wherein the length is in the range of μm. 6. The exudate suction device according to claim 1, further comprising a means for extending the skin in a direction opposite to the inclination of the projection needle. 7. The exudate suction device according to claim 6, wherein the means for extending the skin is an elastic body. 8. The exudate suction device according to claim 6, wherein the means for stretching the skin comprises a member having a large coefficient of friction and a mechanism for generating a horizontal force on the skin surface. 9. The leachate suction device according to claim 1, wherein the projection needle is a hollow needle made of metal, resin, or semiconductor. 10. The leachate suction device according to claim 1, wherein the projection needle and the extraction plate member are integrally formed of resin. 11. The leachate suction device according to claim 1, wherein the projection needle and the extraction plate member are integrally formed of a semiconductor material.