JP2007202665A - Needle unitary type biosensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a needle unitary type biosensor which is simply operable by a patient to be measured while restricting the amount of blood to be drawn to its necessary minimum. <P>SOLUTION: The needle unitary type biosensor keeps an electrode, a spacer and a puncture needle which is punctured into the skin of a specimen by a drive means to draw the blood integrated between at least two electrically insulating substrates, and a puncture port for puncturing into the skin of the specimen and a blood drawing guide port for drawing the blood installed as a puncture blood drawing port at the same location. A track on which the puncture needle is driven and a sample conveying path for guiding the blood onto the electrode branch off the puncture blood drawing port. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a needle-integrated biosensor. More particularly, the present invention relates to a needle-integrated biosensor having a configuration in which a puncture needle for piercing the skin to obtain blood and a biosensor for collecting and analyzing body fluid taken on the surface of the skin are integrated.

Conventionally, a diabetic patient himself collects blood and measures a blood glucose level which is a glucose level in blood. In this case, the patient uses a blood collection device called a lancet that attaches and detaches the blood collection needle. is doing. In such a measurement method, the patient must carry a set of measuring instruments consisting of several points, such as a blood glucose analyzer, a lancet, a blood collection needle and an analytical element, and combine them when necessary to perform the measurement. However, it takes a long time to train and it takes a considerable amount of time before a reliable measurement can be performed by the patient. Actually, measurements at parts other than the fingertips and forearms (abdominal wall, earlobe, etc.) are difficult even for an expert. In recent years, biosensors that can be measured with a sample volume of 1 μl or less have been developed due to the need for supplying less invasive specimens with less pain. The work of supplying accurately becomes very difficult. As a result, the measurement fails, and the patient who is the subject needs to puncture again and replace the biosensor, and the measurement must be performed again.
JP-A-9-266898 Japanese Patent Publication No. 8-20412

Thus, several needle-integrated biosensors have been devised. First, in the needle-integrated biosensor disclosed in Patent Document 3, the puncture needle and the biosensor are placed in different positions in a pen-type (two-color ballpoint pen-like) measuring device equipped with a puncture needle drive unit. The blood glucose is measured by placing the tip of the pen-like measuring device against the skin of the subject and puncturing it, exposing the biosensor to the tip, and collecting blood. However, in this method, the troublesomeness of setting the needle and the biosensor in the measuring device has not been solved.
JP 2000-217804 A

Further, in the needle integrated biosensor disclosed in Patent Document 4, the puncture needle is entrusted to external drive, and the puncture needle moves in parallel along the longitudinal direction of the elongated piece-like biosensor. Have taken. However, this type has a problem that blood collection is more than necessary because blood collection is sent to the entire space sharing the sample conveyance path and the puncture needle passage.
Republished 2002-056769

  It is an object of the present invention to provide a needle-integrated biosensor that can be easily operated by a patient who is a subject and can suppress the amount of blood collected to the minimum necessary.

  An object of the present invention is configured such that an electrode, a spacer, and a puncture needle for collecting blood by piercing the subject's skin with an electrode, a spacer, and driving means are integrated between at least two electrically insulating substrates. In a biosensor in which a puncture port for puncturing the skin and a blood collection introduction port for collecting blood are provided at the same location as a puncture blood collection port, a trajectory driven by the puncture needle and a sample transport path for guiding blood onto the electrode Is achieved by a needle-integrated biosensor characterized by branching from the puncture blood collection port.

  The needle-integrated biosensor according to the present invention provides a puncture port and a blood sampling introduction port at the same location, thereby enabling a patient who is a subject to easily perform a series of operations such as blood sampling and measurement. Independent of the trajectory driven by the puncture needle and the sample transport path that guides blood onto the electrode prevents blood from flowing into the puncture needle, minimizes the volume of the collected blood sample, and accurately defines the blood volume By doing so, an excellent effect is provided such as providing a needle-integrated biosensor capable of quantitative measurement of blood components.

  As the substrate, it is sufficient if it is electrically insulating, for example, plastic, biodegradable material, paper or the like is used, and preferably polyethylene terephthalate is used. Further, an oxygen permeable material can be used, and in this case, since the reagent can be prevented from being reduced, there is an effect of suppressing variation in the measured value depending on the state of reduction. Here, in the present invention, at least two substrates are used, and these substrates can be connected by a connecting portion.

  The electrode is formed on the substrate by a screen printing method, a vapor deposition method, a sputtering method, a foil pasting method, a plating method, etc., and the materials include carbon, silver, silver / silver chloride, platinum, gold, nickel, copper, Examples include palladium, titanium, iridium, lead, tin oxide, and platinum black. Here, as the carbon, carbon nanotubes, carbon microcoils, carbon nanohorns, fullerenes, dendrimers, or derivatives thereof can be used.

  The electrode may be a two-pole method formed by a working electrode and a counter electrode or a three-pole method formed by a working electrode and a counter electrode, a reference electrode, or an electrode method having more poles. Here, when the three-pole method is adopted, in addition to the electrochemical measurement of the measurement target substance, it is possible to measure the moving speed of the blood sample introduced into the conveyance path, thereby measuring the hematocrit value. Moreover, you may be comprised by 2 or more sets of electrode systems. These electrodes are formed on a single substrate or separately on two substrates.

  A reagent layer (electrode reaction part) can be formed on the substrate on which the electrode is formed. The reagent layer is formed by a screen printing method or a dispenser method, and the reagent layer can be immobilized on the electrode surface or the substrate surface by an adsorption method involving drying or a covalent bonding method. Examples of the reagent disposed in the electrode reaction part of the biosensor include those containing glucose oxidase as an oxidase and potassium ferricyanide as a mediator when configured for blood glucose measurement. When the reagent is dissolved by the blood, the enzyme reaction is started. As a result, potassium ferricyanide coexisting in the reaction layer is reduced and potassium ferrocyanide, which is a reduced electron carrier, is accumulated. The amount is proportional to the substrate concentration, ie the glucose concentration in the blood. The reduced electron carrier accumulated for a certain time is oxidized by an electrochemical reaction. An electronic circuit in the main body of the measuring apparatus, which will be described later, calculates and determines the glucose concentration (blood glucose level) from the anode current measured at this time, and displays it on the display unit arranged on the main body surface.

  In addition, a surfactant and lipid can be applied around the blood collection port and on the surface of the electrode or reagent layer (electrode reaction part). By applying a surfactant or lipid, the sample can be moved smoothly.

  Here, in the conventional puncture needle movable sensor, there is a possibility that the puncture needle contained in the inside of the sample conveyance path is contaminated by the application of the reagent layer, surfactant or lipid in the sample transport path. In order to prevent excessive contamination, measures such as not applying these reagents around the tip of the puncture needle have been taken, but the puncture needle drive trajectory is provided at a site different from the electrode. The biosensor has an excellent effect that it is not necessary to avoid such problems.

  In the biosensor in which the reagent layer is provided on the electrode filled with the above blood collection, the blood collection and the reagent react when the blood collected from the blood collection port contacts the reagent layer on the electrode. This reaction is monitored as an electrical change at the electrode.

  In addition to the electrodes, spacers are formed on the insulating substrate. The spacer is made of at least one of an adhesive, a resist, and an insulating substrate, and plays a role of ensuring a space for a trajectory driven by the puncture needle and a sample transport path for guiding blood onto the electrode.

  Since the adhesive is used for bonding the substrates together, it is not particularly limited as long as it does not react or dissolve with the substrates and can bond the substrates. For example, an acrylic resin adhesive, etc. Is used. The adhesive layer can be formed by a screen printing method, and is formed with a thickness of about 5 to 500 mm, preferably about 10 to 100 mm. The adhesive layer also functions as a spacer as described above. In addition, the said reagent can also be contained in an adhesive bond layer.

  The resist is used to define the electrode area and is not particularly limited as long as it does not react or dissolve with the substrate in the same manner as the adhesive layer. For example, an ultraviolet curable vinyl / acrylic resin is used. , Urethane acrylate resins, polyester acrylate resins, and the like. The resist layer is also formed by screen printing or the like with a thickness of about 5 to 500 mm, preferably about 10 to 100 mm. The resist layer also functions as a spacer as described above. The purpose of using the resist is to clarify the electrode pattern mainly as described above, and to insulate the sample transport path where the reagent layer is not present, in addition to defining the electrode area. Therefore, the resist layer may or may not have the same pattern as the adhesive layer. In the latter case, the resist layer is preferably formed on the electrode substrate for insulation.

A track composed of at least one of an adhesive, a resist, and an insulating substrate forms a trajectory driven by the puncture needle and a sample transport path that guides blood onto the electrode. The trajectory driven by the puncture needle and the sample conveyance path for guiding blood onto the electrode are puncture blood collection so that the puncture port for puncturing the skin of the subject and the blood collection inlet for collecting blood are at the same location. In addition to being provided as a mouth, these are configured to be branched from the puncture blood sampling mouth. As such an aspect,
(1) A puncture needle drive track other than the puncture port is provided on the sample transport path other than the blood collection inlet via a separator made of an electrically insulating substrate. At this time, the sample transport path and the puncture needle drive trajectory can be made upside down.
(2) The sample transport path other than the blood sampling inlet is provided on an electrically insulating substrate different from the position where the puncture needle drive track other than the puncture opening is provided.
Etc. are exemplified. An air discharge hole is provided at the puncture port end of the puncture needle drive track formed in this way. In the case of (1), the air discharge hole is formed on the electrically insulating substrate positioned relative to the separator forming the puncture needle drive track, and in the case of (2), the puncture needle drive track. Are formed on at least one of the insulating substrates. This air discharge hole can stop the flow of blood sample into the puncture needle drive orbit, so that it is possible to prevent the waste of the blood sample and to quantify the blood components by the prescribed blood sample volume. There is an effect.

  The puncture needle is used for collecting body fluid from the skin of the subject, and it is necessary to puncture the subject. Therefore, the puncture needle has a strength that can withstand this, and is preferably sharp. In order to suppress pain, a thin puncture needle is preferable. As long as the puncture needle satisfies the above conditions, any of known materials such as metal and resin can be used. Specifically, for example, a 21-33 gauge needle manufactured by Terumo Corporation is used. . The puncture needle may be a hollow needle or a rod-like needle as long as it can penetrate the subject's skin. Furthermore, since the puncture needle needs to be hygienicly stored in the biosensor until it is used, a photocatalytic function effective for antibacterial and antiviral effects may be imparted to the needle tip surface. In that case, a film of titanium oxide or titanium dioxide is desirable. The puncture needle is disposed in such a manner that it does not overlap with the air discharge hole provided in the puncture needle drive track provided in the sensor.

  When the connection part is provided between the two substrates, the substrate having the above-described configuration in which the puncture needle is disposed is folded along this to manufacture a biosensor as a folded molded body. You can also. As the connecting portion, the length of the connecting portion is not less than the thickness of the spacer, that is, 0.5 to 4 mm, preferably 1.0 to 3.0 mm, and preferably at least two places are provided between two substrates. If such a connection part is about 0.5 to 0.9 mm in length on the electrically insulating substrate, for example, a gear-shaped thin disk whose convex part is a blade is used as a broken line A connecting portion having a length of about 1 to 4 mm is hinge-molded by punching out an electrically insulating substrate with a mold. Here, when the connecting portion has a length of about 1 to 4 mm, there is no need to prevent the warping by fixing the folded portion by thermocompression bonding or using a fixture. In the case of a biosensor that is such a folded molded body, a connecting portion as a folding line is provided so as to be horizontal in the long axis direction of a long substrate, and further, an electrode or the like is formed and then folded along the connecting portion. After that, a large number of biosensors can be manufactured at once by punching into the sensor shape. The needle-integrated biosensor manufactured by such a manufacturing method has very good reproducibility and has features that cannot be achieved by a conventional lamination method.

  In the needle-integrated biosensor of the present invention, it is desirable that a series of operations of puncture, blood collection, and measurement be performed by a measurement device having a puncture drive. In this case, for example, it is desirable that the puncture drive has a mechanism in which the needle penetrates the soft material of the biosensor and breaks through the skin of the subject, and a mechanism that quickly returns to the original position immediately after the puncture. When the measuring device is not provided with a driving means, a driving means such as a spring integrated with the needle is preferably used.

  As a measuring device for a needle-integrated biosensor, a measuring device that uses operability and durability to ensure repeatable and reliable measurement using a needle-integrated biosensor and is easy to carry is used. For example, by inserting a needle-integrated biosensor into the introduction part at the bottom with the puncture needle support facing upward and connecting the terminal of the biosensor to the connector of the measuring device, measurement becomes possible. In addition, the preparation for the measurement is completed by pulling the trigger to give the puncture drive to the inside of the needle integrated biosensor, and then the puncture / blood sampling / measurement sequence is automatically activated by pressing the puncture start button switch. However, a system that finally leads to the measurement result is used.

  An example of the structural features of the measuring device will be described in more detail. In this measurement apparatus, the puncture needle drive unit and the measurement apparatus unit are integrated, and the puncture needle drive unit includes a trigger unit, a puncture start button unit, and a drive unit using an elastic body such as a spring. On the other hand, for the measuring device section, the sensor introduction section, the connector, the electrochemical measurement circuit, the memory section, the operation panel, the measurement section that measures the electrical values at the electrodes of the biosensor, and the display that displays the measurement values at the measurement section Further, a radio wave, for example, Bluetooth (registered trademark) can be mounted as a wireless means. With such a slide structure, since the puncture drive is received while the needle-integrated biosensor is securely held, the strength of the entire measuring apparatus can be increased. The measurement device can further include a mechanism that can recognize the left-right asymmetric structure with the puncture needle of the needle-integrated biosensor as the center line by the protruding portion of the measurement terminal.

  The puncture drive of the measuring device is preferably a mechanism that returns quickly after tapping the upper part of the needle-integrated biosensor in the vertical direction, and preferably has a mechanism that can adjust the depth at which the skin of the subject is punctured.

  The measuring device must have voice guidance and voice recognition functions for visual impairment caused by diabetes, measurement data management functions using the built-in radio clock, communication functions for medical data such as measurement data, and charging functions. Can do.

  A measurement method in the measurement unit of the measurement apparatus is not particularly limited, and potential step chronoamperometry, coulometry, cyclic voltammetry, or the like can be used.

As described above, the needle-integrated biosensor of the present invention does not limit the user, that is, can handle a universal project.

  The needle-integrated biosensor according to the embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following examples unless it exceeds the gist.

  FIG. 1 shows an example of a needle-integrated biosensor according to the present invention. In a), an electrically insulating substrate 1 and an adhesive layer 6 are shown. In the electrically insulating substrate 1, the base portion 2 provided with the conductors 5 constituting the electrodes 10 and the terminals 15, the cover portion 3, and the spacer portion 4 are connected by a perforation 8 that forms a connection portion. The thickness of the adhesive layer 6 is also used as a spacer.

  b) shows a state before the adhesive layer 6 is formed on the electrically insulating substrate 1 and the spacer portion 4 is folded over the base portion 2. Here, the round through-hole 7 provided on the electrically insulating substrate 1 serves as an air outlet when the biosensor is formed. Furthermore, the pattern for the base portion 2 of the adhesive layer 6 provided on the electrically insulating substrate 1 is different from the pattern for the cover portion 3, and the sample transport path 9 (electrode reaction portion 10) is determined by the base portion 2 pattern. ) Is formed. In addition, a puncture needle drive track 18 is formed between the patterns of the adhesive layer 4 together with the insulating substrate that forms the spacer portion 4. As shown here, the puncture needle drive track 18 and the sample transport path 9 are branched at the puncture blood collection port 16 so that the puncture needle cannot contact the electrode. Further, an air discharge hole 7 is provided at the end of the puncture blood sampling port 16 of the puncture needle drive track 18, and a mechanism that can prevent blood from flowing into the sensor from this portion is employed. As a result, it is possible to prevent blood from flowing into the puncture needle and to eliminate unnecessary introduction of the sample body fluid, and therefore, it is possible to achieve an excellent effect that the blood components can be quantified based on the defined blood volume.

  c) A side view of the puncture needle 13 is shown in i). The puncture needle portion 13 includes a puncture needle 11 and a support body 12 that supports the puncture needle 11, and the support body 12 further includes a drive transmission portion 19 that transmits external driving to the puncture needle 11 and a puncture needle portion 13 provided inside the biosensor. It comprises a rail guide 20 for fitting into the rail. c) ii) shows a view of the puncture needle 13 seen from the front. A puncture needle 11 is disposed at the center, and a support body 12 including an external drive transmission portion 19 and a rail guide 20 is shown at the base. c) iii) shows a state before the puncture needle portion 13 shown in c) i) is inserted into the rail 21 of the biosensor in the middle of assembling.

  d) shows a state in which the puncture needle portion 13 is arranged so as to fit into the rail 21 of the biosensor and the puncture needle drive track 18. Here, the rail guide 20 of the puncture needle portion 13 needs to be thinner than the thickness of the rail 21 so that the rail guide 20 can move horizontally within the rail 21 of the biosensor. d) shows a state before the puncture needle portion 13 is stored inside the biosensor by folding the cover portion 3 toward the base portion 2. Here, the external drive transmission part 19 of the puncture needle part 13 can move only in the range of the space 17 provided in the base part 2 and the cover part 3, and the tip of the puncture needle 11 is the base part 2 before and after the puncture. It is shown that it fits inside the sensor rather than the upper air discharge hole 7. For this reason, blood collection after the puncture cannot enter deeper than the air discharge hole 7, so that the contact between the puncture needle 11 and the blood collection does not occur.

  e) shows a plan view (e) i)) and a bottom view (e) ii)) of the needle-integrated biosensor 14 assembled by the above steps. As shown in this figure, the movement range of the puncture needle unit 13 is defined by the external drive transmission unit 19 of the puncture needle unit 13 and the rail guide of the biosensor. f) i) shows a front view of the needle-integrated biosensor 14. As shown here, an external drive transmission portion 19 of the puncture needle portion 13 protrudes from the biosensor body. This convex part is a part which receives the drive of the puncture drive part built in the measuring apparatus. f) ii) shows a left side view of the needle-integrated biosensor 14. f) iii) shows a right side view of the needle-integrated biosensor 14.

  g) is a diagram related to the same biosensor as e) i), but h) the cross-sectional parts of each figure of the needle-integrated biosensor 14 shown in i) to iv) are indicated by i to iv, respectively. h) In i) and iii), a biosensor formed by folding the electrically insulating substrate 1 connected by the connecting portion using the adhesive layer 6 so as to become the base portion 2, the spacer portion 4, and the cover portion 3. Is shown. In h) ii), the puncture needle 11 and the rail 21 are not in contact with each other, and the position of the puncture needle is far behind the puncture opening than the air discharge hole 7 before and after puncturing. It has been shown. h) iv) shows a state in which the puncture needle 11 is arranged in the puncture needle drive track 18. The puncture needle 11 is not in direct contact with the puncture needle drive track 18, and this state is the same in a series of puncture operations.

FIG. 2 shows an example of use of the needle-integrated biosensor 14. a) before puncture, b) during puncture, and c) after puncture. Further, i) shows a plan view of the needle-integrated biosensor 14, and ii) shows a bottom view of the needle-integrated biosensor 14. As is clear from these drawings, the puncture needle 11 protrudes from the puncture blood collection port 16 in the puncture needle portion 13 during puncture.

It is a figure which shows an example of the needle-integrated biosensor according to the present invention. It is a figure which shows the usage example of the needle | hook integrated biosensor which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrically insulating board | substrate 2 Base part 3 Cover part 4 Spacer part 5 Conductor 6 Adhesive layer 7 Through hole (air discharge hole)
8 Perforation 9 Sample transport path 10 Electrode (reagent layer)
DESCRIPTION OF SYMBOLS 11 Puncture needle 12 Puncture needle support body 13 Puncture needle part 14 Needle integrated biosensor 15 Terminal 16 Puncture blood sampling port 17 Space 18 Puncture needle drive track 19 External drive transmission part 20 Rail guide 21 Rail

Claims (8)

In order to puncture the skin of a subject, an electrode, a spacer, and a puncture needle for collecting blood by piercing the subject's skin by means of driving means are integrated between at least two electrically insulating substrates. In the biosensor in which the puncture port and the blood collection introduction port for collecting blood are provided as the puncture blood collection port at the same location,
A needle-integrated biosensor characterized in that a trajectory driven by a puncture needle and a sample transport path for guiding blood onto an electrode are branched from a puncture blood collection port.   The needle-integrated biosensor according to claim 5, wherein the trajectory driven by the puncture needle and the sample transport path for guiding blood onto the electrode are formed of at least one of an adhesive, a resist, and an electrically insulating substrate.   The needle-integrated biosensor according to claim 1, wherein the sample transport path other than the puncture port and the track for driving the puncture needle other than the blood sampling introduction port are separated by an insulating substrate.   The needle-integrated biosensor according to claim 1, wherein the sample transport path other than the puncture port is provided on an electrically insulating substrate different from the position where the trajectory for driving the puncture needle other than the blood sampling introduction port is provided.   The needle-integrated biosensor according to claim 1, wherein an air discharge hole is provided at an end portion of the puncture port of the trajectory driven by the puncture needle.   The needle-integrated biosensor according to claim 5, wherein the puncture needle is disposed in a manner that does not overlap the air discharge hole.   The needle-integrated biosensor according to claim 1, wherein the driving means is a driving means external to the biosensor or a driving means integrated with a needle. The needle-integrated biosensor according to any one of claims 1 to 7, wherein the needle-integrated biosensor is formed by folding a single electrically insulating substrate on which an electrode is formed.

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