Interstitial fluid collection method and interstitial fluid collection kit and interstitial fluid collection sheet used for the method

A interstitial fluid collection kit for collecting interstitial fluid extracted via micropores formed in a skin is disclosed. The kit includes a marker sheet that has an adhesive face and that defines a region in which micropores are to be formed; a transparent retention sheet having an adhesive face; and a collecting body that is retained by a part of the adhesive face of the retention sheet and that collects interstitial fluid extracted from the skin.

TECHNICAL FIELD

The present invention relates to a method of collecting interstitial fluid extracted from micropores formed in skin of a living body, and a interstitial fluid collection kit and a interstitial fluid collection sheet used for the method.

BACKGROUND ART

Conventionally, there has been known a method of forming micropores in a skin of a living body to thereby collect living body components via the micropores for measurement (see Patent Literatures 1 and 2 for example).

Patent Literature 1 discloses a method according to which particles are caused to collide with skin to form micropaths in the skin after which an occlusive dressing including gel for collecting analyte is attached to a processing region including the micropaths, to thereby collect the analyte in the gel via the micropath.

Patent Literature 2 discloses a blood glucose value analysis apparatus that includes: a main body to which an extraction cartridge for collecting interstitial fluid can be attached; a receiving section for the positioning of a puncture tool for forming micropores in the skin; and a belt section for attaching the receiving section to an arm of a user.

The receiving section in Patent Literature 2 has an opening for exposing the skin of the user. This receiving section is configured so that the processing region of the skin including the micropores formed by the puncture tool is exposed through the opening. The main body is rotatably attached by a hinge to the receiving section. The main body is configured so that the main body is rotated to the receiving section to allow the extraction cartridge attached to the main body is placed on the processing region of the skin, thus providing the positioning of the extraction cartridge to the processing region of the skin. Then, while the receiving section being attached to the arm by the belt section, the extraction of interstitial fluid is carried out by the extraction cartridge.

CITATION LIST

Patent Literature

Patent Literature 1: Published Japanese translation of a PCT application No. 2005-513428Patent Literature 2: Japanese Unexamined Patent Publication No. 2007-236844

SUMMARY OF INVENTION

Technical Problem

In order to perform an accurate extraction of interstitial fluid, it is required to correctly position a medium for extracting the interstitial fluid at the region of the skin including the micropores. However, Patent Literature 1 does not disclose any positioning of an occlusive dressing to the processing region.

On the other hand, according to the apparatus disclosed in Patent Literature 2, the main body attached with the extraction cartridge is configured to be rotatable to the receiving section having the opening through which the processing region is exposed, to thereby provide the positioning of the extraction cartridge at the processing region. However, this configuration requires the receiving section to be attached to the arm by the belt section during extraction of interstitial fluid. Thus, if interstitial fluid must be extracted for a long time, the belt must be kept attached to the arm.

The present invention has been made in view of the situation as described above. It is an objective of the present invention to provide an interstitial fluid collection method and an interstitial fluid collection kit and an interstitial fluid collection sheet used for the method by which a medium for extracting interstitial fluid can be easily positioned, without causing a burden on a user, on a processing region of a skin.

Solution to the Problem

A interstitial fluid collection method according to a first aspect of the present invention (hereinafter also simply referred to as “method”) is characterized in including:a step of adhering, to skin, a marker sheet that has an adhesive face and that defines a region in which micropores are to be formed;a step of forming micropores in the region defined by the marker sheet adhered to the skin;a step of adhering an interstitial fluid collection sheet to the skin by an adhesive face of a retention sheet by using the marker sheet adhered to the skin as a marker so that a collecting body is placed on the region in which micropores are to be formed, the interstitial fluid collection sheet including a transparent retention sheet having an adhesive face, and a collecting body that is retained by a part of the adhesive face of the retention sheet and that collects interstitial fluid extracted from the skin; anda step of collecting interstitial fluid from the skin via the micropores to the collecting body.

According to the method of the present invention, the marker sheet adhered to the skin defines a micropore formation region. Furthermore, the retention sheet that retains the collecting body for collecting interstitial fluid is transparent. Thus, by using the marker sheet as a marker, the collecting body can be easily placed in the micropore formation region. Interstitial fluid can be extracted only by adhering the sheets (marker sheet, interstitial fluid collection sheet) to the skin. Thus, even if interstitial fluid is extracted for a long time, it is not necessary to keep attaching an aid such as a belt to the arm, so that the burden to the user is reduced.

The collecting body is retained by a part of the adhesive face of the retention sheet. Due to a manufacture reason, there may be a variation in the position of the collecting body in the adhesive face. In such a case, the position at which the collecting body is adhered undesirably varies even when the interstitial fluid collection sheet is adhered to a predetermined region of the skin based on the outer shape of the interstitial fluid collection sheet. However, according to the present invention, since the retention sheet is transparent, even when the position of the collecting body in the retention sheet varies, the interstitial fluid collection sheet can be adhered to the skin, while visually recognizing the position of the collecting body, so that the collecting body is positioned within the region defined by the marker sheet. This consequently allows, regardless of the variation of the position of the collecting body in the retention sheet, the collecting body to be placed in the micropore formation region.

The term “transparent” herein means to include colorless transparent and colored transparent. The term “transparent” is not limited to completely-transparent and means to include “translucent” so long as such transparency is obtained that allows the position of the collecting body to be confirmed via the retention sheet. For example, the term “transparent” herein also includes a configuration where the part at which the collecting body is retained and the periphery thereof of a few millimeters are transparent and the other parts are not transparent. The term “transparent” herein also includes a configuration where a grid-like pattern is given to the retention sheet and the patterned part is not transparent, so long as the position of the collecting body can be confirmed through transparent parts other than the pattern.

A interstitial fluid collection kit according to the second aspect of the present invention is a interstitial fluid collection kit for collecting interstitial fluid extracted via micropores formed in a skin, characterized in comprising:a marker sheet that has an adhesive face and that defines a region in which micropores are to be formed;a transparent retention sheet having an adhesive face; anda collecting body that is retained by a part of the adhesive face of the retention sheet and that collects interstitial fluid extracted from the skin.

As in the above-mentioned method, a interstitial fluid collection sheet of the present invention is configured so that the marker sheet adhered to the skin defines a micropore formation region. Furthermore, the retention sheet for retaining the collecting body for collecting interstitial fluid is transparent. Thus, by using the marker sheet as a marker, the collecting body can be easily placed in the micropore formation region. The interstitial fluid can be extracted only by adhering the sheets (marker sheet, interstitial fluid collection sheet) to the skin. Thus, even if interstitial fluid is extracted for a long time, it is not necessary to keep attaching an aid such as a belt to the arm, so that the burden to the user is reduced.

Furthermore, the collecting body is retained by a part of the adhesive face of the retention sheet. Due to a manufacture reason, there may be a variation in the position of the collecting body in the adhesive face. In such a case, the position at which the collecting body is adhered undesirably varies even when the interstitial fluid collection sheet is adhered to a predetermined region of the skin based on the outer shape of the interstitial fluid collection sheet. However, according to the present invention, since the retention sheet is transparent, even when the position of the collecting body in the retention sheet varies, the interstitial fluid collection sheet can be adhered to the skin, while visually recognizing the position of the collecting body, so that the collecting body is positioned within the region defined by the marker sheet. This consequently allows, regardless of the variation of the position of the collecting body in the retention sheet, the collecting body to be placed in the micropore formation region.

Furthermore, in the interstitial fluid collection kit, the marker sheet is preferably a frame-like sheet having an opening that defines the region.

Furthermore, in the interstitial fluid collection kit, the marker sheet preferably consists of a plurality of small pieces by which the region is defined.

Furthermore, in the interstitial fluid collection kit, the collecting body is preferably gel. In this case, the gel is preferably colored.

Furthermore, in the interstitial fluid collection kit, the collecting body is preferably smaller than the opening of the marker sheet.

Furthermore, in the interstitial fluid collection kit, the marker sheet is preferably colored.

Furthermore, in the interstitial fluid collection kit, the marker sheet preferably has a positioning mark corresponding to a positioning mark provided on a flange provided at a side at which a micropore formation tool for forming micropores is abbutable to the skin.

Furthermore, it is preferable that the interstitial fluid collection kit further comprises a marker retention sheet that has a first adhesive face adhered to a back face of the adhesive face of the marker sheet by a first adhesive that retains the marker sheet to the first adhesive face, and the adhesive face of the marker sheet has a second adhesive having a strength higher than the strength of the first adhesive. In this case, the marker retention sheet preferably has a positioning mark corresponding to a positioning mark provided on a flange provided at a side on which a micropore formation tool for forming micropores is abuttable to the skin.

Furthermore, in the interstitial fluid collection kit, the adhesive face of the retention sheet is preferably adhered to the back face of the adhesive face of the marker sheet with a lower adhesive strength than the adhesive strength of the marker sheet to the skin.

Furthermore, a interstitial fluid collection sheet according to the third aspect of the present invention is a interstitial fluid collection sheet for collecting interstitial fluid extracted via micropores formed in a region defined by a marker sheet adherable to skin, comprising:a transparent retention sheet having an adhesive face; anda collecting body that is retained by a part of the adhesive face of the retention sheet and that is capable of collecting extracted interstitial fluid.

Furthermore, in the interstitial fluid collection sheet, the adhesive face of the retention sheet is preferably adhered to a back face of the adhesive face of the marker sheet with an adhesive strength lower than an adhesive strength of the marker sheet to skin.

Furthermore, in the interstitial fluid collection sheet, the collecting body is preferably gel.

Furthermore, in the interstitial fluid collection sheet, it is preferable that the gel itself is colored or a colored intermediate layer is used.

Advantageous Effects of Invention

According to an interstitial fluid collection method and an interstitial fluid collection kit and an interstitial fluid collection sheet used for the method of the present invention, a medium for extracting interstitial fluid can be positioned in a processing region of the skin without causing a burden to a user.

DESCRIPTION OF EMBODIMENTS

The following section will describe in detail, with reference to the attached drawings, an interstitial fluid collection method and an interstitial fluid collection kit and an interstitial fluid collection sheet used for the method in the present embodiment.

The method for example in the present embodiment relates to a technique of collecting interstitial fluid from micropores formed in skin. First, the following section will describe a puncture tool for forming such micropores.

FIG. 1is a perspective illustration diagram of an example of a puncture tool200used for the interstitial fluid collection method of the present embodiment.FIG. 2is a perspective view of a fine needle chip300attached to the puncture tool200shown inFIG. 1.FIG. 3is a cross-sectional illustration diagram of a skin in which micropores are formed by the puncture tool200.

As shown inFIGS. 1 to 3, the puncture tool200is a device that is used in the following manner. Specifically, the puncture tool200is attached with the fine needle chip300subjected to a sterilization processing and fine needles301of the fine needle chip300are abutted to the epidermis of a living body (skin400of a subject) to thereby form interstitial fluid extraction holes (micropores401) in the skin400of the subject. The fine needle301of the fine needle chip300is sized so that, when the micropores401are formed by the puncture tool200, the micropores401are held within the epidermis of the skin400and are prevented from reaching the dermis.

As shown inFIG. 1, the puncture tool200comprises a housing201, a release button202provided at the surface of the housing201, and an array chuck203and a spring member204both of which being provided in the housing201. A lower end face (a face abutable to skin) of a lower section201aof the housing201includes an opening (not shown) through which the fine needle chip300can pass. The spring member204has a function to bias the array chuck203in a puncture direction. The lower end of the array chuck203can be attached with the fine needle chip300. The lower face of the fine needle chip300includes a plurality of fine needles301. The fine needle chip300has a lower face having a size of 10 mm (long side)×5 mm (short side). The puncture tool200has a fixing mechanism (not shown) that fixes the array chuck203against the biasing force of the spring member204while the array chuck203being pushed in an upward direction (anti-puncture direction). When a user (subject) depresses the release button202, the fixing of the array chuck203by the fixing mechanism is released. Then, the biasing force by the spring member204causes the array chuck203to move in the puncture direction. Then, the fine needles301of the fine needle chip300protruding through the opening puncture the skin.

The housing201includes a flange205as shown by diagonal lines inFIG. 1. The flange205includes a notch206as a positioning mark (which will be described later). Although only one notch is shown inFIG. 1, the flange205at the back side ofFIG. 1also includes the same notch206as that shown at the front side.

Next, a interstitial fluid collection kit will be described. The interstitial fluid collection kit is used to collect interstitial fluid extracted through micropores formed in the skin using the puncture tool as described above. The interstitial fluid collection kit comprises: a marker sheet; a marker retention sheet for retaining the marker sheet; a collecting body for collecting interstitial fluid extracted from the skin; and a retention sheet for retaining the collecting body. The following section will describe the respective elements.

FIG. 4is a perspective illustration diagram of a marker sheet2retained by a marker retention sheet1.FIG. 5is a cross-sectional diagram taken along the line A-A ofFIG. 4.FIG. 6is a perspective illustration diagram of the marker sheet. InFIGS. 4 to 6, andFIGS. 7 to 9which will be described later, for providing easy understanding, the thickness of the sheet for example is drawn exaggeratingly.

The marker sheet2is composed of: a sheet body2a; and an pressure sensitive adhesive layer2bformed on one face of the sheet body2a. A face on which the pressure sensitive adhesive layer2bis formed functions as an adhesive face. The marker sheet2is a frame-like sheet having an opening3. This opening3defines a region in which micropores are formed. Specifically, as described later, the fine needle chip300of the puncture tool200is abutted in the opening3to thereby form micropores. Then, the collecting body is placed in the opening3to extract interstitial fluid from the micropores. The sheet body2aof the marker sheet2can be formed, for example, by a polyethylene film, a polypropylene film, a polyester film, and a polyurethane film as well as foam, knitted fabric, woven fabric, and nonwoven fabric. The thickness of the sheet body2ais not particularly limited and is generally about 0.025 to 0.5 mm. The relative sizes of the marker sheet and the retention sheet can be appropriately changed. However, the marker sheet desirably has a smaller size than that of the retention sheet when the sheet body2aof the marker sheet is made of foam or a nonwoven fabric for example, and thus the drying of the collecting body during the collection of interstitial fluid is facilitated.

The marker sheet2is adhered on an oval-shaped peeling sheet4that also functions as a mat board. The marker retention sheet1, which also has an oval shape, is adhered on the peeling sheet4so as to cover the marker sheet2. The marker retention sheet1has an opening5that has the same size as that of the opening3of the marker sheet2. The marker retention sheet1is adhered on the peeling sheet4so that the opening5is aligned with the opening3of the marker sheet2. The sheet body1aof the marker retention sheet1is preferably formed by a polyethylene film, a polypropylene film, a polyester film, or a polyurethane film for example and is more preferably formed by a polyethylene film, a polyester film, and a polyurethane film. The sheet body1aalso can be formed by foam, knitted fabric, a woven fabric, and a nonwoven fabric for example in addition to a film. The thickness of the sheet body1ais not particularly limited and is generally about 0.025 to 2.0 mm. The peeling sheet4exemplarily includes a high-quality paper processed by mold release agent such as silicone resin, a paper substrate such as a glassine paper, or a sheet such as a polyester film. The thickness of the peeling sheet4is not particularly limited and is generally about 0.025 to 0.5 mm.

As in the marker sheet2, the marker retention sheet1is composed of the sheet body1aand an pressure sensitive adhesive layer1bformed on one face of the sheet body1a. A face on which the pressure sensitive adhesive layer1bis formed functions as an adhesive face. The periphery of the marker retention sheet1includes semicircular notches6at positions opposed to sandwich the opening5. By placing the notches206of the flange205of the puncture tool200so as to exactly match the notches6, the puncture tool200can be placed at a predetermined puncture position.

The pressure sensitive adhesive layer2bof the marker sheet2and the pressure sensitive adhesive layer1bof the marker retention sheet1have adhesive strengths that are respectively adjusted so that the adhesive face of the marker sheet2has an adhesive strength (the second adhesive strength) higher than the adhesive strength of the adhesive face of the marker retention sheet1(the first adhesive strength). This adjustment can be carried out, for example, by a known method such as by for changing the type of pressure sensitive adhesive, by adjusting the amount of tackifier to be included in pressure sensitive adhesive, or by adjusting the timing when tackifier is included in the pressure sensitive adhesive. The adjustment also can be carried out by processing of an adherend face including, for example, the coating of a surface of the sheet body2aof the marker sheet2abutted to the pressure sensitive adhesive layer1bof the marker retention sheet1or a minute convexoconcave processing of the surface of the sheet body2a.

As described above, by allowing the adhesive face of the marker sheet2to have a higher adhesive strength than that of the marker retention sheet1, when the marker sheet2retained by the marker retention sheet1is adhered on the skin and then the marker retention sheet1is peeled from the skin, only the adhesion having a lower adhesive strength between the marker retention sheet1and the marker sheet2is released, thus allowing only the marker sheet2to be left on the skin. As a result, the frame-like shaped marker sheet2can be adhered on the skin easily.

FIG. 6is a perspective illustration diagram of the marker sheet2adhered to the skin. As described above, the marker sheet2has a frame-like shape having the opening3. The size of the opening3differs depending on the size of a collecting body placed within the opening and is generally about 1 to 20 mm×1 to 20 mm and is 8 mm×14 mm in the present embodiment. The opening is sized so as to accommodate a collecting body12which will be described later. The marker sheet2defines a region in which micropores are formed and functions as a marker for placing the collecting body in the micropore formation region. Thus, the marker sheet2is preferably colored with blue, red, or green, for example, so that the color of the marker sheet2can be distinct from the color of the skin of the living body. The marker sheet2colored in the manner as described above allows the collecting body to be placed within the opening3in an easy and accurate manner.

FIG. 7is a perspective illustration diagram of a interstitial fluid collection sheet10that comprises: the retention sheet11; and the collecting body12retained by this retention sheet11.FIG. 8is a cross-sectional diagram taken along the line B-B ofFIG. 7.

The collecting body12is made of water-retentive gel that can retain interstitial fluid extracted from a subject skin and includes pure water as extraction medium. The gel may be any gel so long as the gel can collect interstitial fluid and can achieve the objective of the present invention. The gel is preferably formed of at least one type of hydrophilic polymer selected from the group consisting of polyvinyl alcohol and polyvinylpyrrolidone. The gel may be formed of hydrophilic polymer that may be polyvinyl alcohol only, polyvinylpyrrolidone only, or a mixture thereof. The gel is more preferably formed of hydrophilic polymer that is polyvinyl alcohol only or a mixture of polyvinyl alcohol and polyvinylpyrrolidone.

The gel can be formed by a method of cross-linking hydrophilic polymer in aqueous solution. The gel can be formed by coating aqueous solution of hydrophilic polymer on base material to form a coating film to thereby cross-link hydrophilic polymer included in the coating film. Cross-linking methods of hydrophilic polymer include chemical cross-linking and radiation cross-linking. However, radiation cross-linking is desirably used because this method suppresses gel from being mixed with impurities of various chemical substances.

In the present embodiment, the collecting body12has a rectangular parallelepiped shape, and a face thereof abbuttable to the skin has a size of 7 mm×12 mm. This size is smaller than the size of the opening3of the marker sheet2. Thus, the collecting body12can be placed within the opening3without protruding from the opening3. This can consequently increase the area on which the collecting body12is abutted to the micropore formation region, thus efficiently collecting interstitial fluid extracted through the micropores. The collecting body12has a slightly larger size than that of a face of the fine needle chip in which fine needles are formed. This can consequently enable the use of the micropore formation region without waste to collect interstitial fluid, thus giving no excessive burden on the subject.

It is preferable that, in order to place the collecting body12within the opening3of the marker sheet2in an easy and accurate manner as in the marker sheet2, the gel itself constituting the collecting body12is colored or a colored intermediate layer is used. The intermediate layer is used for the purpose of improving the anchoring property of the gel to the adhesive face and is directly placed on the surface of the pressure sensitive adhesive layer. The intermediate layer is preferably the one having a laminate structure of a nonwoven fabric of polyethylene terephthalate (PET) and a PET film or the one of a polyethylene film. The intermediate layer preferably has the same area as that of an area in which the gel is provided to the skin.

A retention sheet11is composed of: an oval-shaped sheet body11a; and an pressure sensitive adhesive layer11bformed on one face of the sheet body11a. A face on which the pressure sensitive adhesive layer11bis formed functions as an adhesive face. The collecting body12is provided at substantially the center of a similarly oval-shaped peeling sheet13that also functions as a mat board. The retention sheet11is adhered to the peeling sheet13so as to cover the collecting body12. The collecting body12is retained to the retention sheet11by a part of the adhesive face of the retention sheet11. In order to avoid the drying of the collecting body12during the collection of interstitial fluid, the retention sheet11has an area that can cover the collecting body12. Specifically, by covering the collecting body12by the retention sheet11, the space between the skin and the retention sheet11can be sealed in an air-tight manner during the collection of interstitial fluid. This can consequently restrain the water included in the collecting body12from evaporating during the collection of interstitial fluid. In the present embodiment, the retention sheet11has a larger area than the area of the marker sheet2so that the retention sheet11can sufficiently cover the collecting body12(seeFIGS. 10(a) and10(b)).

The sheet body11aof the retention sheet11is colorless and transparent or colored and transparent. Thus, the collecting body12retained by the retention sheet11can be visually recognized easily at the surface-side of the sheet body11a(an opposite face to the pressure sensitive adhesive layer11b). The sheet body11ais preferably made of material having a low moisture permeability in order to prevent the evaporation of interstitial fluid and the drying of the collecting body. Material having a low moisture permeability includes, for example, a polyethylene film, a polypropylene film, a polyester film, and a polyurethane film among which a polyethylene film and a polyester film are preferred. The thickness of the sheet body11ais not particularly limited and is generally about 0.025 to 0.5 mm.

The interstitial fluid collection sheet10is adhered to the skin by the adhesive face of the retention sheet11so that the collecting body12is placed in the micropore formation region within the opening3of the marker sheet2. During this process, since the retention sheet for retaining the collecting body12is transparent, the marker sheet2can be used as a marker to thereby easily place the collecting body12in the micropore formation region.

The collecting body12is retained by a part of the adhesive face of the retention sheet11. Due to a manufacture reason, there may be a variation in the position of the collecting body12in the adhesive face. In such a case, the position at which the collecting body12is adhered undesirably varies if the interstitial fluid collection sheet10is adhered to a predetermined region of the skin based on the outer shape of the interstitial fluid collection sheet10, which also may cause a lowered measurement accuracy. However, according to the present embodiment, since the retention sheet11is transparent, even when the position of the collecting body12in the retention sheet11varies, the interstitial fluid collection sheet10can be adhered to the skin, while visually recognizing the position of the collecting body12, so that the collecting body12is positioned within the region defined by the marker sheet2. This consequently allows, regardless of the variation of the position of the collecting body12in the retention sheet11, the collecting body12to be placed in the micropore formation region.

The following section will describe an advantage of the interstitial fluid collection method according to the present embodiment with reference to the drawings.FIGS. 9(a) and9(b) (Prior Art) are illustration diagrams in the case where an opaque retention sheet is used.FIG. 9(a) shows the collecting body retained at the center of the retention sheet.FIG. 9(b) shows the collecting body retained at a position dislocated to the right side of the center of the retention sheet.FIGS. 10(a) and10(b) are illustration diagrams in the case where a transparent retention sheet is used.FIG. 10(a) shows the collecting body retained at the center of the retention sheet.FIG. 10(b) shows the collecting body retained at a position dislocated to the right side of the center of the retention sheet. InFIGS. 9(a) and9(b) as well asFIGS. 10(a) and10(b), those components that can be visually recognized are shown by the solid line while those components that cannot be visually recognized are shown by the broken line.

InFIGS. 9(a) and9(b), a configuration will be exemplary described where the collecting body is retained at the center of the retention sheet having substantially the same size as that of the marker sheet and the outline of the marker sheet is aligned with the outline of the retention sheet. As shown inFIG. 9(a), when the collecting body is retained at the center of the retention sheet (i.e., when no variation is caused in the position of the collecting body), the collection body can be placed in the micropore formation region by aligning the retention sheet, even when the retention sheet is opaque, with the outline of the marker sheet without confirming the position of the collecting body. However, when the collecting body is retained at a position dislocated from the center of the retention sheet as shown inFIG. 9(b) (i.e., when a variation is caused in the position of the collecting body), the collecting body is not placed in the micropore formation region even when the retention sheet is adhered by aligning the outline of the marker sheet with the outline of the retention sheet. To prevent this, the retention sheet must be adhered while confirming the position of the collecting body. However, the position of the collecting body can not be visually recognized because of the opaque retention sheet, thus the collection body can not be accurately placed in the micropore formation region.

In contrast with this, inFIGS. 10(a) and10(b), the existence of the transparent retention in accordance with the present inventive sheet allows the collecting body and the marker sheet to be visually recognized via the retention sheet as shown by the solid line. Thus, the collecting body can be accurately placed within the region defined by the marker sheet while visually confirming the position of the collecting body both in the case where the collecting body is retained at the center of the retention sheet as shown inFIG. 10(a) and the case where the collecting body is retained at a position dislocated from the center of the retention sheet as shown inFIG. 10(b). As described above, the use of the transparent retention sheet can allow the collecting body to be accurately placed in the micropore formation region, regardless of the variation of the position of the collecting body retained in the retention sheet.

In the configuration exemplarily shown inFIGS. 9(a) and9(b), the retention sheet is opaque. Thus, in order to align the outline of the marker sheet with the outline of the retention sheet, the marker sheet must have substantially the same size as that of the retention sheet, thus failing to secure a sufficient area at which the retention sheet is adhered to the skin. When the retention sheet is transparent on the other hand, the size of the retention sheet to the marker sheet is not limited. Thus, the size of the retention sheet can be sufficiently increased to the marker sheet as shown inFIGS. 10(a) and10(b). This consequently can increase the area at which the retention sheet is adhered to the skin, thus increasing the retention strength of the retention sheet for retaining the collecting body.

The adhesive face of the retention sheet11is adhered to the back face of the adhesive face of the marker sheet2with a lower adhesive strength than the adhesive strength by the marker sheet2to the skin. This prevents, when the retention sheet11is peeled from the skin after the collection of interstitial fluid, the marker sheet2from being peeled from the skin together with the retention sheet11. This can consequently prevent the components of the horny layer attached to the marker sheet2from being measured together with the interstitial fluid collected in the collecting body12, thus improving a measurement accuracy. An adhesive strength by the pressure sensitive adhesive layer11bof the retention sheet11can be adjusted as in the adjustment of the adhesive strengths of the pressure sensitive adhesive layers of the marker sheet2and the marker retention sheet1. The pressure sensitive adhesive layer may be formed by pressure sensitive adhesive including, for example, acrylic pressure sensitive adhesive, rubber-base pressure sensitive adhesive, silicone-base pressure sensitive adhesive, and urethane-base pressure sensitive adhesive. The interstitial fluid collection sheet10of the present embodiment is frequently adhered to the skin surface for a relatively long time. Thus, these pressure sensitive adhesives are preferably restrained from causing skin irritation. From the viewpoint of restraining skin irritation, acrylic pressure sensitive adhesive and rubber-base pressure sensitive adhesive are preferred and acrylic pressure sensitive adhesive is more preferred.

Next, the following section will describe a interstitial fluid collection method using the above-described interstitial fluid collection kit.

FIG. 11is a diagram illustrating steps of the interstitial fluid collection method using the above-described interstitial fluid collection kit. First, the skin400of a subject is cleaned by alcohol for example to remove substances (e.g., sweat, dust) that may disturb a measurement result. Thereafter, the marker sheet2retained by the marker retention sheet1is adhered to a predetermined position of the skin of the subject (step (a)).

Next, micropores are formed in the skin by the puncture tool200attached with the fine needle chip300(step (b)). Specifically, the position of the puncture tool200is set by aligning the notches206formed in the flange205at the lower end of the puncture tool200with the notches6of the marker retention sheet1. This consequently provides the alignment between the opening formed in the lower end face of the lower section201aof the housing201and the opening3of the marker sheet2. When the release button202is depressed in this status, the fixing of the array chuck203by the fixing mechanism is released and the array chuck203is moved to the skin side by the biasing force of the spring member204. Then, the fine needle chip300attached to the lower end of the array chuck203passes through the opening formed in the lower end face of the lower section201aof the housing201and is abutted to the skin region of the subject defined by the marker sheet2. As a result, the micropores401are formed in the epidermis of the subject skin.

Next, the puncture tool200is removed from the subject skin and the marker retention sheet1is peeled from the subject skin (step (c)). As described above, the adhesive face of the marker retention sheet1has an adhesive strength lower than the adhesive strength of the adhesive face of the marker sheet2. Thus, the marker sheet2is prevented from being peeled together with the marker retention sheet1, thus allowing the marker sheet2to be continuously adhered to the subject skin.

Next, the interstitial fluid collection sheet10is adhered to the subject skin using the marker sheet2as a marker so that the collecting body12is placed within the opening3of the marker sheet2(step (d)). In this case, since the retention sheet11in the present embodiment is transparent, the interstitial fluid collection sheet10can be adhered to the skin, while the position of the collecting body12being visually confirmed, so that the collecting body12is positioned within the region defined by the marker sheet2.

By leaving the collecting body12placed in the micropore formation region for a predetermined time of 60 minutes or more and preferably 180 minutes or more for example, interstitial fluid extracted through the micropores is collected in the collecting body12(step (d)). In the present embodiment, since the retention sheet for retaining the collecting body is adhered to the skin, there is no need to attach an aid such as a belt to the arm, even when interstitial fluid is collected for a long time of 60 minutes to 180 minutes, thus reducing the burden to the user.

After the predetermined time after the placement of the collecting body12in the micropore formation region, the interstitial fluid collection sheet10is peeled from the subject skin (step (e)). During this process, since the adhesive face of the retention sheet11is adhered to the back face of the adhesive face of the marker sheet2with a lower adhesive strength than the adhesive strength of the marker sheet2to the skin, the marker sheet2is prevented from being peeled from the skin together with the retention sheet11.

The interstitial fluid collected in the collecting body12is subjected to an analysis of components by an analyzer shown inFIG. 12for example.

FIG. 12is a perspective illustration diagram illustrating the appearance of a living body component analyzer. The living body component analyzer20is used to acquire a glucose concentration and a sodium ion concentration included in the interstitial fluid collected in the collecting body12. The living body component analyzer20is used in the manner as described below. First, as shown by the dashed line inFIG. 12, the interstitial fluid collection sheet10removed from the subject skin is adhered to an analysis cartridge40. Then, this analysis cartridge40is placed in a cartridge receiving section22of the living body component analyzer20. Then, the living body component analyzer20carries out a predetermined analysis processing on the analysis cartridge40placed in the cartridge receiving portion22and the interstitial fluid collection sheet10adhered to the analysis cartridge40to thereby acquire a glucose concentration and a sodium ion concentration of the interstitial fluid collected in the interstitial fluid collection sheet10.

The living body component analyzer20includes a thick rectangular parallelepiped-shaped housing. A top panel in the upper face of the housing includes a concave portion21. The concave portion21includes the cartridge receiving portion22that is a concave portion more deeply formed than the concave portion21. The concave portion21is also connected to a movable top panel23that has substantially the same thickness as the height of a side wall of the concave portion21. The movable top panel23in the status shown inFIG. 12can be stored in the concave portion21by being folded down around a pivot axis23a. The movable top panel23stored in the concave portion21also can be raised as shown inFIG. 12. The cartridge receiving portion22is sized so as to be able to accommodate the analysis cartridge40which will be described later.

The movable top panel23is supported by the pivot axis so as to be biased in a direction along which the movable top panel23is stored in the concave portion21. Thus, the analysis cartridge40placed in the cartridge receiving portion22is pushed down from the upper side by the movable top panel23.

The living body component analyzer20includes therein a solution sending section24and a liquid discharge section25. The solution sending section24is a mechanism to send liquid to the analysis cartridge40placed in the cartridge receiving portion22. The solution sending section24sends liquid via a nipple24ato the analysis cartridge40placed in the cartridge receiving portion22. The liquid discharge section25is a mechanism to discharge liquid sent from the solution sending section24to the analysis cartridge40. The liquid discharge section25discharges, via a nipple25a, the liquid sent to the analysis cartridge40.

The living body component analyzer20further comprises: a glucose detection section31; a sodium ion detection section32; a display section33; an operation section34; and a control section35.

The glucose detection section31is provided in the back face of the movable top panel23(i.e., a face opposed to the cartridge receiving portion22when the movable top panel23is stored in the concave portion21). The glucose detection section31comprises a light source31afor emitting light and a light-receiving section31bfor receiving reflected light of light emitted from this light source31a. Thus, the glucose detection section31is configured to emit light to the analysis cartridge40placed in the cartridge receiving portion22and to receive the reflected light from the analysis cartridge40having received the light. The analysis cartridge40includes a glucose reactant41that can react chemically with the glucose in the interstitial fluid collected from the living body to change the color thereof. The glucose detection section31can detect the change in absorbance due to glucose as described above based on the reflected light and can determine the quantity of glucose based on the resultant reflected light.

The sodium ion detection section32is provided in the bottom face of the cartridge receiving portion22. The sodium ion detection section32includes a rectangular plate-like member provided in the bottom face of the cartridge receiving portion22. At substantially the center of the plate-like member, a pair of sodium ion concentration measurement electrodes is provided. The sodium ion concentration measurement electrodes include a sodium ion-selective electrode that includes a sodium ion selective film and that is made of silver/silver chloride and a counter electrode of a silver/silver chloride electrode.

The control section35is provided in the living body component analyzer20and comprises a CPU, a ROM, and a RAM for example. The CPU reads and executes a program stored in the ROM to thereby control the operations of the respective sections. The RAM is used as a program development region when a program stored in the ROM is executed.

Next, the following section will describe the operation of the living body component analyzer20having the configuration as described above.

The interstitial fluid collection sheet10for which the interstitial fluid collection is completed is stored in a storage portion of the analysis cartridge40. Next, the analysis cartridge40is placed in the cartridge receiving portion22.

Upon receiving an instruction for executing the measurement, the solution sending section24sends liquid via the nipple24ato the storage portion of the analysis cartridge40and the storage portion is filled with the liquid. Then, the living body component analyzer20in this status is left for a predetermined time, thus allowing the components in the interstitial fluid to be diffused from the collecting body12to the liquid. As described above, when the retention sheet11is peeled from the skin, the marker sheet2is prevented from being peeled from the skin together with the retention sheet11. This consequently prevents the horny layer components attached to the marker sheet2from dissolving in the liquid, thus preventing the horny layer components from having an influence on the measurement accuracy.

After passage of the predetermined time, the solution sending section24sends air to the storage portion. By the air sent from the solution sending section24, the liquid filled in the storage portion is sent to a flow path provided in the lower face of the analysis cartridge40and is further sent via the flow path to the glucose reactant41. The liquid sent to the flow path contacts with the sodium ion detection section32. The liquid sent to the glucose reactant41reacts with the glucose reactant41to thereby change the color of the glucose reactant.

The control section35applies a fixed voltage to the sodium ion concentration measurement electrode to acquire a current value. Based on the acquired current value and a calibration curve stored in the control section35in advance, the control section35acquires the sodium ion concentration.

The control section35acquires glucose concentration based on a change amount between the received light amount of the light-receiving section31bprior to the color formation of a color forming dye and the received light amount of the light-receiving section31bafter the color formation of the color forming dye.

Other Modification Examples

The present invention is not limited to the above-described embodiments and can be subjected to various modifications.

For example, in the above-described embodiment, the marker sheet is retained by the marker retention sheet and the marker retention sheet is used to adhere the marker sheet to the skin. However, the marker retention sheet as described above can be omitted.

FIG. 13is a perspective illustration diagram of a marker sheet102as described above. This marker sheet102has an oval shape and is composed of a sheet body102aand an pressure sensitive adhesive layer102b. The marker sheet102is adhered to a peeling sheet104and includes an opening105at the center thereof. Peripheries opposed to one another to sandwich the opening105have four notches106each of which has shape corresponding to each of the notches formed in the flange of the puncture tool.

The marker sheet102is adhered to the subject skin after the peeling sheet104is peeled. Then, the notches106and the notches formed in the flange are used to position the puncture tool. Then, the puncture tool is used to form micropores in the opening105.

After the formation of the micropores, a interstitial fluid collection sheet is adhered to the subject skin so that the collecting body of the interstitial fluid collection sheet is positioned within the opening105. After the extraction of interstitial fluid, the interstitial fluid collection sheet is peeled from the skin and the above-described measurement is carried out.

The marker sheet is not limited to a single sheet. The marker sheet can be composed of a plurality of small pieces so long as the marker sheet can define a region in which micropores are formed and can function as a marker for placing the collecting body.FIG. 14illustrates a marker sheet302composed of four small pieces302aeach of which has a substantially L-like shape.FIG. 15illustrates a marker sheet402composed of two short strips402aand two long strips402b. In the case of the marker sheets shown inFIG. 14andFIG. 15, it is troublesome to accurately adhere each small piece to the skin and it is also difficult to adhere each small piece to a predetermined position. Thus, it is preferable that the marker sheet composed of a plurality of small pieces is retained by a marker retention sheet and this marker retention sheet is adhered to the predetermined position of the skin and the marker retention sheet is peeled after the puncture.

Another modification example is also possible where the back face of the marker sheet is surrounded by an pressure sensitive adhesive layer so that the formation of micropores in the skin is performed substantially simultaneously with the adhesion of the marker sheet to the skin. Specifically, while the shape of the flange of the puncture tool is being aligned with the notches of the marker sheet, the pressure sensitive adhesive formed on the back face of the marker sheet is adhered to the flange.

The notch as a positioning mark is not limited to a semicircular shape and also can appropriately have other shapes such as a triangular or rectangular shape. When a plurality of notches are used, notches having different shapes to one another can be used. In this case, the flange of the puncture tool also includes notches having corresponding different shapes to one another. This can provide the positioning of the puncture tool easily when the opening through which the fine needle chip passes is not provided at the center of a face of the puncture tool that is abutted to the skin. The number of the notches is preferably two or more and is particularly preferably four. In this case, each of the four cutouts is preferably provided at substantially the center of each side of two sides symmetric to each other.

Another modification example of the positioning mark is also possible where the positioning mark has a convex shape corresponding to a hole made in the flange of the puncture tool. Other modification examples also include a positioning mark additionally prepared as an adhesive tape that is adhered to the marker sheet.

Although the present embodiment has shown an example in which gel is used as the collecting body, the collecting body is not limited to gel and may be any water-absorbing material including mesh and paper for example so long as the material can collect extracted interstitial fluid.