JP4166878B2 - Biosensor used in lancet-integrated body fluid measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention can measure a substance to be detected contained in a body fluid such as blood glucose concentration (hereinafter referred to as “blood glucose level”), and collects and measures body fluid from the skin by an integrated operation. The present invention relates to a biosensor.
[0002]
BACKGROUND OF THE INVENTION
In order to treat diabetes, it is necessary to keep the blood glucose level of the patient in a normal range, and blood glucose level management by the patient himself is an important treatment method. In particular, when the blood glucose level is maintained in a normal range by insulin injection by the patient himself, appropriate blood glucose level measurement by the patient himself is indispensable.
[0003]
Portable blood glucose level measuring devices used for such purposes are already on the market. Among them, for example, Japanese Patent Application No. 10-166894 has been filed as an application in which a lancet and a sensor have an integral structure.
[0004]
This body fluid measuring device is a body fluid measuring device provided with a main body and a mounting body that is used by being mounted on the main body, and the mounting body is arranged along the skin contact surface and the skin contact surface. The sensor can be moved between the advanced position where the tip protrudes from the skin contact surface and the retracted position where the tip penetrates from the skin contact surface, and is biased toward the retract position by the elastic body. A puncture body, and when the mounting body is mounted, the main body is in contact with the electrodes of the sensor included in the mounting body and is electrically connected to the electrodes, and an electrical signal obtained through the terminal And a drive mechanism for driving the puncture body forward so that the puncture body takes an advanced position.
[0005]
In the measurement, the user wears the mounting body on the main body. When the drive mechanism of the main body is operated while pressing the skin contact surface against the skin such as the fingertip or earlobe, the puncture body at the retracted position is advanced, and the pointed tip protrudes from the skin contact surface and damages the skin. . The puncture body returns to the retracted position by the action of the next instantaneous elastic body. If the device is kept as it is, blood flowing out of the skin permeates the sensor, and the sensor outputs a reaction current. This electric current is converted into a specific component concentration in the blood by an electronic circuit and displayed on, for example, a display arranged on the surface of the main body.
[0006]
In a preferred embodiment, the sensor in the wearing body has a plate shape extending along the skin contact surface as a whole, and a body fluid passage in which the reaction portion faces the inner surface in the thickness direction is provided. It has a configuration in which a through hole is formed and communicated with the body fluid passage and through which the tip of the puncture body can pass.
[0007]
According to this configuration, since the through-hole through which the puncture body passes and the body fluid passage in the sensor communicate with each other, blood flowing out from the wound on the skin directly enters the through-hole, and subsequently the reaction unit Is filled in the body fluid passage.
[0008]
However, in the bodily fluid measuring device described in the above-mentioned Japanese Patent Application No. 10-166894, a gap formed between the sensor and the skin other than the blood flowing out from the wound attached to the skin directly enters the through hole. There was a problem of getting in.
[0009]
[Problems to be solved by the invention]
The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a sensor in which blood flowing out from a wound on a skin surely directly enters a through hole by improving the sensor.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, after intensive research, in the sensor in the wearing body, the skin contact surface of the sensor arranged along the skin is subjected to a hydrophobic treatment, and the above-mentioned skin contact surface Three-dimensional shielding for preventing blood from entering between the skin formed using a hydrophobic material and the skin contact surface in the vicinity of the vicinity of the through hole for allowing movement of the tip of the puncture body It is the biosensor characterized by having arranged.
[0011]
Embodiment
[Example 1]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is an overall external view of the body fluid measuring device, FIG. 2 is an enlarged longitudinal sectional view showing details of the wearing body in a state in which the puncture body is retracted, and is a view corresponding to a section taken along line II-II in FIG. 3 is an enlarged longitudinal sectional view showing details of the mounting body in a state where the puncture body has advanced, FIG. 4 is a bottom view of the mounting body, and FIG. 5 is a bottom view of the mounting body with the sensor removed. .
[0012]
As shown in FIGS. 1 to 3, the body fluid measuring device 10 is used in combination of a main body 20 and a mounting body 30. The main body 20 has switch buttons, an LCD display 22 and the like disposed on the upper surface thereof. A cylindrical portion 21 is formed to extend from the front portion of the main body 20, and a cap-like mounting body 30 which will be described in detail later is attached to the tip portion thereof. In addition, inside the main body 20, a drive mechanism (23, 32) for driving the puncture body 31 provided in the mounting body 30 forward, and a circuit such as a microcomputer are incorporated. In FIG. 1, the code | symbol 23 comprises a part of said drive mechanism, and has shown the press part for a user to press manually.
[0013]
Details of an example of the mounting body 30 are shown in FIGS. The mounting body 30 has a generally cap shape including a cylindrical portion 34 and a bottom wall portion 35 positioned so as to close the tip of the cylindrical portion 34, and a main portion thereof is manufactured by resin molding. The inner diameter of the cylindrical portion 34 is caused to correspond to the outer diameter of the front cylindrical portion 24 of the body 20, Ru can be easily mounted as to cover the the front cylindrical portion 24.
[0014]
The puncture body 31 and the biosensor 36 are integrated into the bottom wall portion 35 of the cap-shaped mounting body 30. A cylindrical recess 35A having a cylindrical wall 35b and a bottom wall 35c is formed in the bottom wall 35 at the center position of the mounting body 30, and a center hole 35d is formed in the bottom wall 35c of the recess 35A. Opened.
[0015]
On the other hand, the puncture body 31 is made of metal on a resin guide body 31A having a guide shaft portion 31a slidably fitted in the center hole 35d and a flange portion 31b integrally formed at one end of the guide shaft portion 31a. The puncture needle 31c is integrally inserted, and the retracted position shown in FIG. 2 is always obtained by the elastic body 37 interposed between the flange portion 31b and the upper surface of the plate-like biosensor 36 described later, that is, the flange. The portion 31b is biased toward a position where it abuts against the bottom wall 35c of the depressed portion 35A. At this retracted position, the rear end of the guide shaft portion 31a protrudes to the inside of the bottom wall 35c, and the puncture needle 31c retracts to the back side of the plate-like biosensor 36 described later. As described above, as an aspect of the elastic body 37 that urges the puncture body 31 toward the retracted position, a compression coil spring made of metal or resin is used as shown in FIGS.
[0016]
A plate-like biosensor 36 is attached to the bottom wall portion 35 of the mounting body 30 so as to cover the depressed portion 35A in which the puncture body 31 is accommodated. As shown in FIGS. 6 to 8, the biosensor 36 has a through hole 36a through which the puncture needle 31c of the puncture body 31 can pass, and communicates with the through hole 36a and has a thickness parallel to the bottom wall portion 35. comprising a fluid passage 36b extending, it has a configuration in which the reaction portion 36k is formed on the inner wall of the body fluid passage 36b.
[0017]
More specifically, the biosensor 36 forms an insulating base plate 36A having a working electrode 36c and a counter electrode 36d formed on the upper surface, and a groove 36e exposing a part of the working electrode 36c and the counter electrode 36d. Plate-like spacers 36B and 36B laminated on the insulating base plate 36A, and a plate-like cover 36C further laminated on the plate-like spacers 36B and 36B are provided. Hereinafter, a manufacturing process of the plate-like biosensor 36 will be described.
[0018]
As shown in FIG. 9, a base plate 36A having a rectangular shape in plan view made of a resin insulating sheet having a thickness of 0.2 mm, for example, is prepared. FIG. 10 shows a parallel surface opposite to the surface on which the electrode is formed in the base plate 36A, that is, the skin contact surface portion. As shown in FIG. 10, it is formed a hydrophobic portion 363 a performs pre hydrophobic treatment the very near vicinity of the at least the through-hole 36 a. The hydrophobizing treatment referred to here is to deteriorate the familiarity with water. Here, the hydrophobic treatment to order the compound is not particularly limited as long as the surface of the resin insulating sheet can hydrophobic or water-repellent, for example, polyurethane resins, polyacrylic resins, polyester Resin, polyamide resin, polyvinyl chloride resin, polystyrene resin, fluorine resin, other rubber-modified products, etc., as long as it is not a water-soluble resin or a highly hygroscopic resin, Any known resin used can be used. In addition, as a method of hydrophobizing treatment, any known technique such as a printing method in which a liquid mainly composed of the above resin is infiltrated into a predetermined portion and then dried, or a coating with a water repellent agent can be used. it can. The base plate 36A is previously formed with a through hole 36a having a diameter of 1.5 mm, for example. A working electrode 36c and a counter electrode 36d are formed in a film shape on the upper surface of the base plate 36A by screen printing using graphite ink. The working electrode 36c has a planar form in which a thin projecting portion 36g extends from an end region 36f to be a terminal portion (a region where only the oblique line is applied to the working electrode 36c), while the counter electrode 36d has It has a planar form having projecting portions 36i and 36i extending in a bifurcated manner so as to sandwich the projecting portion 36g on the working electrode 36c side from both ends from an end region 36h to be a terminal portion (a region where only the diagonal line is provided on the counter electrode 36d). Yes. The through hole 36a is located in the vicinity of one protrusion 36i of the counter electrode 36d.
[0019]
Next, the resist layer 36j (solid line) is left leaving the band-like regions in which the projecting portions 36g, 36i, 36i of the working electrode 36c and the counter electrode 36d are arranged in the vertical direction and the end regions 36f, 36h of the working electrode 36c and the counter electrode 36d. A region shaded with an alternate long and short dash line is printed.
[0020]
Subsequently, spacer plates 36B and 36B having a planar shape equivalent to that of the resist layer 36j are disposed so as to overlap the resist layer 36j. As the spacer plate 36B, for example, a resin plate having a thickness of 0.2 mm is employed, and a double-sided tape type in which an adhesive layer is provided on the front and back surfaces is used. Thereby, a concave groove 36e sandwiched between the spacer plates 36B and 36B is formed (see FIG. 8), and the projecting portions 36g, 36i, 36i, 36i, 36d of the working electrode 36c and the counter electrode 36d are formed in a band-like region at the bottom of the concave groove 36e. 36i will be exposed side by side. The width of the concave groove 36e is set to 1.5 mm, for example, and the length is set to 3 mm, for example.
[0021]
Next, a reaction reagent layer 36k as shown well in FIG. 8 is formed in the band-like region at the bottom of the concave groove 36e. When configured as a blood glucose level measurement sensor, this reaction reagent includes glucose oxidase which is an oxidase and potassium ferricyanide as a mediator. The reaction reagent layer 36k is formed by, for example, a dispensing method.
[0022]
Next, as shown in FIG. 9, a cover plate 36C having a rectangular shape in plan view having a through hole 362b corresponding to the through hole 36a of the base plate 36A is overlaid on the spacer plates 36B and 36B. This biosensor 36 is completed. That is, as shown in FIGS. 6 to 8, a body fluid having a horizontally long rectangular cross section extending in the vertical direction by closing the groove 36e formed by the base plate 36A and the spacer plates 36B and 36B with the cover plate 36C. A passage 36b is formed, and a reagent layer 36k (reaction part) that contacts the working electrode 36c and the counter electrode 36d is formed on the inner surface of the body fluid passage 36b, and the body fluid passage 36b is connected to the plate-like biosensor 36. It will be connected to the through hole 36a. The position opposite to the transmembrane hole 36 a that put the fluid passage 36b is allowed to open, fluid by capillary action to the fluid passage 36b through the reaction portion 36k through the through hole 36a as described later ( (Blood) is encouraged to be introduced.
[0023]
The plate-shaped biosensor 36 formed as described above has a position of the puncture needle 31c and a position of the through hole 36a of the biosensor 36 on the bottom wall portion 35 of the mounting body 30 as shown in FIG. Affixed to match. As shown in FIGS. 4 and 5, the bottom wall portion 35 of the mounting body 30 has a working electrode 36c and a terminal portion 36f for the counter electrode 36d that are exposed at both ends of the base plate 36A of the biosensor 36, Round holes 362c and 362d corresponding to 36h are formed. The round holes 362c and 362d are for bringing the tips of the connector pins 25a and 25a on the main body 20 side into contact with the terminal portions 36f and 36h when the mounting body 30 is mounted on the main body 20. The bottom wall 35 of the mounting body 30 is also formed with arcuate openings 36m, 36m so as to sandwich the biosensor attachment region.
[0024]
As shown in FIGS. 2 and 3, the main body 20 has a pressing rod 32 that is pressed and driven by the pressing portion 23 in its axial direction (direction indicated by an arrow in the figure) and is moved by a spring. The drive mechanisms 23 and 32 are configured by being always urged rearward.
[0025]
Next, the usage method or operation | movement of the bodily fluid measuring apparatus 10 provided with the said structure is demonstrated, referring FIG. 1 thru | or FIG.
[0026]
When using the body fluid measuring device 10, the user attaches the mounting body 30 to the cylindrical portion 21 of the main body 20 (see FIG. 1).
[0027]
The pressing portion 23 is pressed in a state where the surface of the bottom wall portion 35 of the mounting body 30, that is, the skin contact surface 35a is pressed against an appropriate part of the patient's skin, such as a fingertip or an earlobe. Then, the tip of the pressing rod 32 inside the main body 20 presses the rear end portion of the guide shaft portion 31a of the puncture body 31, and the puncture body has a stroke until the pressing rod 32 contacts the back side of the recessed portion 35A of the mounting body 30. 31 is pushed forward against the elasticity of the elastic body 37. At this time, the puncture needle 31c of the puncture body 31 protrudes a predetermined length from the lower surface of the biosensor 36, that is, the skin contact surface 35a, through the through hole 36a of the biosensor 36 (state of FIG. 3). When the pressing to the pressing portion 23 is released, the pressing rod 32 returns to its original position by the elasticity of the spring, and the puncture body 31 also immerses the puncture needle 31c from the skin contact surface 35a by the elasticity of the elastic body 37. It returns to the retracted position (state of FIG. 2).
[0028]
Protrusion of the puncture needle 31c from the skin contact surface 35a causes an appropriate damage to the skin. The blood that has flowed out of the wound surely enters the through hole 36a without entering the gap between the skin and the sensor, and is introduced into the body fluid passage 36b in the biosensor 36.
[0029]
[Example 2]
In the same body fluid measuring device as that of the first embodiment, the portion of the insulating base plate 36A in the manufacturing process of the plate biosensor 36 is changed as described below.
[0030]
As shown in FIG. 9, a base plate 36A having a rectangular shape in plan view made of a hydrophobic sheet having a thickness of 0.2 mm, for example, is prepared. Although it is not specifically limited with a hydrophobic sheet here, For example, all well-known hydrophobic sheets, such as an acrylic sheet and a urethane sheet, can be used. Furthermore, when the used hydrophobic sheet is not insulating, for example, a screen printing method using a resist ink or an insulating sheet, for example, a polyethylene terephthalate sheet or the like, are bonded together with an adhesive or the like. You can have it.
[0031]
Using the base plate 36A produced as described above, as in Example 1, it is mounted on the body fluid measuring device, the body fluid measuring device is operated, and puncturing is performed.
[0032]
The blood that has flowed out of the wound surely enters the through-hole 36a without entering the gap between the skin and the sensor, and is introduced into the body fluid passage 36b in the biosensor 36.
[0033]
[Example 3]
In the same body fluid measuring device as that of the first embodiment, the portion of the insulating base plate 36A in the manufacturing process of the plate biosensor 36 is changed as described below.
[0034]
As shown in FIG. 9, a base plate 36A having a rectangular shape in plan view made of a resin insulating sheet having a thickness of 0.2 mm, for example, is prepared. For example, a 1.5 mm diameter through hole 361a is formed in the base plate 36A in advance. Opposing parallel surface to the surface on which the electrodes are formed in the base plate 36A, i.e., a perspective view of the base plate 36 A as viewed from the skin contact surface 35 a shown in FIG. 10. As shown in FIG. 10, the skin on the contact surface 35 a, in close proximity to the periphery of the through hole 361a, it is arranged three-dimensional shield 363a. Here, the three-dimensional shield 363 a say, for example, O-ring or the like, are intended to block the diffusion of flowing out of the wound blood.
[0035]
Using the base plate 36A produced as described above, as in Example 1, it is mounted on the body fluid measuring device, the body fluid measuring device is operated, and puncturing is performed.
[0036]
The blood that has flowed out of the wound surely enters the through-hole 36a without entering the gap between the skin and the sensor, and is introduced into the body fluid passage 36b in the biosensor 36.
[0037]
【The invention's effect】
As described above, according to the present invention, the body fluid measuring device 10 is used to maintain the state where the end surface of the mounting body 30 and the skin contact surface 35a of the biosensor 36 are pressed against the fingertip, earlobe, or the like of the patient. When the operation of projecting the puncture needle 31c is performed, body fluid such as blood sugar level can be appropriately measured without the body fluid entering the gap between the skin and the biosensor 36 .
[0038]
Of course, the scope of the present invention is not limited to the embodiment described above. In the embodiment, the blood glucose level is described as being measured, but the measurement target is not limited to the blood glucose level.
[Brief description of the drawings]
FIG. 1 is an overall external view of a body fluid measuring device according to the present invention.
2 is an enlarged longitudinal sectional view showing details of the mounting body in a state in which the puncture body is retracted, and is a view corresponding to a section taken along line II-II in FIG.
FIG. 3 is an enlarged longitudinal sectional view showing details of the wearing body in a state where the puncture body has advanced.
FIG. 4 is a bottom view of the mounting body.
FIG. 5 is a bottom view of the mounting body with the biosensor removed.
FIG. 6 is a plan view of a biosensor.
FIG. 7 shows VII in FIG.
It is sectional drawing which follows the -VII line.
8 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG.
FIG. 9 is an exploded perspective view of a biosensor.
FIG. 10 is a perspective view of the biosensor as viewed from the skin contact surface side .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Body fluid measuring device 20 Main body 23 Press part (composing a drive mechanism)
25a Connector pin (as terminal of main body)
30 Wearing body 31 Puncture body 32 Pressing rod (constitutes drive mechanism)
35a Skin contact surface 36 Biosensor 36a Through-hole (of biosensor)
36f, 36h terminal part (as sensor electrode)
361a Through-hole (of skin contact surface)
363a Hydrophobic part

Claims (1)

In a body fluid measurement device that is used by attaching a mounting body to a main body, a biosensor used for the mounting body,
The wearing body has a through-hole for allowing movement of the skin contact surface and the tip of the puncture body, and introduces body fluid into the body fluid channel provided with the reaction reagent layer through the through-hole. It can move between the biosensor to be used and the advanced position where the tip protrudes from the skin contact surface and the retracted position where the tip penetrates from the skin contact surface, and is biased toward the retracted position by the elastic body A puncture body,
The main body is a terminal that contacts each electrode of the sensor included in the mounting body when the mounting body is mounted and conducts to the electrodes, and an electronic that determines a measured value based on an electrical signal obtained through the terminal. A circuit, and a drive mechanism for driving the puncture body forward so that the puncture body takes an advanced position,
The biosensor has a hydrophobic treatment applied to the skin contact surface of the sensor , and is formed using a hydrophobic material in the vicinity of the skin contact surface in the vicinity of the through hole. A biosensor, characterized in that a three-dimensional shielding object is provided between the contact surface and a body surface to prevent body fluid from entering .

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