JP2009077871A - Needle integrated sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently introduce blood bleed from a fingertip into a sample space of a sensor chip in a lancet needle integrated sensor body in which a lancet needle is fixed to a sensor chip.
A needle integrated sensor 100 of the present invention includes a sensor chip 200, a lancet needle 300 fixed to one end of the sensor chip 200, a puncture site by the lancet needle 300, a sample introduction port 201 of the sensor chip 200, and the like. A flow path forming body 110 having a bellows structure that is extendable in the flow path direction for forming the flow path 111 is provided. In addition, the needle integrated sensor 100 includes a restoring force generating member 130 made of a leaf spring or the like that restores the compressed flow path forming body 110 to its original shape.
[Selection] Figure 2

Description

  The present invention relates to a needle integrated sensor, specifically, a lancet needle integrated sensor in which a biosensor chip and a lancet needle are integrated.

  A patient collects blood by using a lancet device for blood collection, and measures a blood sugar level or the like in the collected blood. The lancet device is generally composed of a lancet needle such as a puncture needle and a lancet main body for driving the lancet needle. is there.

  Conventionally, blood sugar levels and the like have been measured using such a lancet device and a separate measurement device. Recently, however, a combination of a biosensor and a lancet device is used to collect blood from a blood sample. A lancet-needle integrated sensor device has been proposed that can perform measurement up to a single operation.

  For example, the sensor device described in Patent Document 1 includes a chip body having an internal space, a lancet body having a lancet needle, and a device body on which the chip body is mounted. The lancet body is manufactured to be movable in the internal space of the chip body. After the lancet body is stored in the chip body, the lancet body is set in the device body, and the tip of the lancet needle is projected from the sample introduction port opened at the tip of the chip body by the driving device in the device body. .

  The chip body includes a substrate having a recess for forming an internal space and a cover in which a biosensor is configured. On the inner surface of the cover, a pair of electrodes constituting the biosensor and a terminal portion connected to the electrodes by wiring are provided. The electrode is provided so as to face a groove-like sample space extending from the sample introduction port to the internal space, and a biosensor is constituted by the electrode and a reagent layer applied to the surface of the electrode.

  However, this sensor device has a structure in which the needle is moved in the sample space between the substrate and the cover, and blood is introduced into the sample space from the sample introduction port at the tip of the chip body. Becomes larger. Moreover, since the sample inlet is relatively large and requires a large amount of blood, the pain to the patient is considerably large.

On the other hand, sensor chips that are very small and can be mass-produced by a simple method have been developed. The biosensor chip shown in Patent Document 2 has almost the same structure as the biosensor chip shown in FIG. 3, and a cover and a substrate are formed by bending an insulating plate member, and both are formed by an adhesive layer. A sample introduction port is formed at the tip of the chip by bonding, and a sample space for introducing blood is formed between the two. The substrate is formed with an electrode and an electrode connected by wiring to the electrode by a method such as sputtering. The electrode provided in the vicinity of the sample inlet, the surface of the electrode, and the reagent layer applied in the vicinity thereof A biosensor is constituted by the above. Since this sensor chip has a structure in which plate members are bonded together, it is expected to be very thin and small, reduce the amount of blood required, and significantly reduce the physical burden on the patient. The
International Publication No. WO02 / 056769 International Publication No. WO05 / 010519

  By the way, when a lancet needle such as a needle and a biosensor chip are integrated, in order for blood to be introduced into the sample space from the sample inlet of the biosensor chip, it is necessary to sufficiently spread the blood to the sample inlet. However, when using a thin biosensor chip as in Patent Document 2, a needle having rigidity that can puncture the skin from the sample space to the sample introduction port (that is, a certain thickness is required). ), A structure in which the tip of the needle is popped out from the sample introduction port as in the sensor chip described in Patent Document 1, and then stored in the sample space is not feasible.

  Therefore, it is conceivable to fix the lancet needle to the upper surface of the cover or the lower surface of the substrate of the biosensor chip described in Patent Document 2. However, since the sample introduction port of this biosensor chip is very narrow, there is a possibility that the blood does not sufficiently enter the sample space if the blood transmitted through the needle just contacts the sample introduction port. Further, since the sample introduction port is located away from the needle tip (needle axis), there is a risk that the blood that has bleed will not travel through the needle and reach the sample introduction port.

  On the other hand, it is also conceivable to fix the needle so as to be sandwiched between the folded plate members. In this case, since the needle protrudes from the sample introduction port, it is considered that blood can be easily induced as compared with the case where the needle is fixed to the upper surface (or lower surface) of the biosensor chip. However, when the needle is removed from the fingertip, the sensor chip is also separated from the fingertip together with this, so that the blood that has bleed is not sufficiently distributed to the sample inlet.

  In order to solve such a problem, the present inventors have devised a patent-integrated sensor in which an elastic body having a through hole is arranged at one end of a sensor chip and has filed a patent application. In this needle-integrated sensor, the lancet needle protrudes from the through hole of the compressed elastic body when the sensor collides with the skin vigorously. Thereafter, when the elastic body returns to its original shape by the restoring force, blood flows into the through hole, and a sufficient amount of blood reaches the sample introduction port.

  However, (1) The elastic body is selected from materials such as rubber or sponge made of silicone or urethane, but it is necessary to select a material having an appropriate restoring force. (2) If the distal end surface of the elastic body cannot be kept in sufficient contact with the surface to be punctured, the distal end surface will be separated from the surface to be punctured when returning to its original shape, and blood will be sufficiently in the sensor chip. It is expected not to go around. Therefore, it is desired that the state where the tip surface of the elastic body is in contact with the puncture target surface is desired. (3) Since the collected blood comes into contact with the elastic body, it is considered that the eluate from the elastic body adversely affects the measurement result. That is, the material of the elastic body is required to satisfy these three conditions: (1) an appropriate restoring force, (2) sufficient contact with the puncture target surface, and (3) no adverse effect on the measurement result. . However, there are hardly any materials that satisfy these three conditions. So far, even if it has an appropriate restoring force, the contactability deteriorates over time, and sufficient contactability cannot be ensured, or it has an appropriate restoring force and contactability, but the measurement result is adversely affected. I was doing.

  Further, since the restoring force of the elastic body itself is used, a large force is required at the time of collision with the skin. For this reason, there has been a problem that the sensor launcher cannot be miniaturized and the pain at the time of collision increases.

  Therefore, the present invention provides a structure that can replace such an elastic body, provides a needle-integrated biosensor with a small amount of blood and with little measurement error, and is a small and patient-friendly sensor device. It is intended to provide.

  Therefore, the present invention provides a flow path comprising a bellows structure that expands and contracts in the flow path direction at one end of the sensor chip in a sensor-integrated sensor having a sensor chip and a lancet needle fixed to one end of the sensor chip. The formation is to be provided. Then, a restoring force generating member that restores the compressed flow path forming body to the original shape is provided.

  According to the present invention, a flow path can be secured between the puncture site and the sensor chip without using an elastic body. For this reason, the range of selection of the material of the structure is widened, and it is possible to select a material that does not particularly affect the measurement result. As a result, measurement with little measurement error can be performed with a small amount of blood.

  Moreover, since the flow path forming body is formed of a bellows structure, for example, a thin tube body made of a fluororesin can be used. For this reason, the compression force which should be applied to a flow-path formation body may be small. As a result, the driving device for the needle integrated sensor can be reduced in size, and pain at the time of collision with the skin is reduced. The desired purpose is thus achieved.

  Hereinafter, the present invention will be specifically described with reference to the accompanying drawings. 1 is a schematic perspective view in which a sensor body 10 including a needle integrated sensor 100 is partially broken, FIG. 2 is an enlarged schematic explanatory view of a part of the sensor body 10, and FIG. 4 is a schematic perspective view of an enlarged part of a sensor body 10 according to another embodiment, FIG. 5 is an external view of a sensor device equipped with a needle integrated sensor, and FIG. FIG. 7 is an operation explanatory diagram of the needle integrated sensor 100. FIG.

  The needle integrated sensor 100 of the present invention has a flow path forming body 110 made of a bellows structure that is extendable in the flow path direction provided at one end of the sensor chip 200, the lancet needle 300, and the biosensor chip 200. .

  As shown in FIG. 3, in the sensor chip 200, the cover 220 and the substrate 210 are bonded together with an adhesive layer 240 so as to form a sample space 230 between the cover 220, which is a plate member having an insulating property, and the substrate 210. Has a structured. The sensor chip 200 has a sample introduction port 201 connected to the sample space 230 at the tip thereof. At the rear end of the sample space 230, vent holes 241 connected to the sample space 230 and the outside of the sensor chip 200 are extended on both sides. A pair of electrodes 211 is formed on the substrate 210 so as to face the sample space 230. A voltage extraction terminal 212 electrically connected to the electrode 211 by a conductor is formed at the end of the substrate opposite to the sample introduction port 201. The cover 220 is provided with a reagent layer 221 that faces the sample space 230 and reacts with a sample (specifically, a body fluid such as blood). The pair of electrodes 211 and the reagent layer 221 constitute a biosensor. Examples of such a sensor chip 200 include a chip in which a plate member as described in Patent Document 2 is bent to produce a substrate and a cover. However, in the present invention, the structure shown in Patent Document 2 does not matter, and the sample introduction port 201 is provided between the substrate 210 and the cover 220, and the sample is introduced from the sample introduction port 201. Any structure can be applied.

  The lancet needle 300 is disposed on the cover 220 of the sensor chip 200 and is fixed to the sensor chip 200 by being sandwiched between the fixing member 150 and the support member 160, for example. The lancet needle 300 is fixed by protruding the tip of the lancet needle 300 from the tip of the sensor chip 200 in order to damage the skin (subject). Further, the lancet needle 300 is arranged so that the axis of the lancet needle 300 is substantially parallel to the arrangement direction of the sample space 230 so that the bodily fluid coming out of the skin can be quickly guided to the sample introduction port 201. It arrange | positions so that it may be located in proximity to 201, Preferably just above the sample inlet 201. FIG. In the present invention, since the flow path forming body 110 is mounted as will be described later, as long as the flow path forming body 110 is positioned within the flow path 111 (flow path cross section) formed by the flow path forming body 110, the sample introduction port 201 is somewhat It does not matter if it is in a remote location.

  The support member 160 has a function of holding the sensor chip 200 from the lower surface of the sensor chip 200, and is made of, for example, a plastic material. In addition, the support member 160 includes a wing portion 161 that can be easily held between two fingers so that the device body 2 can be easily attached to and detached from the device body 2. The fixing member 150 has a function of protecting the sensor chip 200 from the upper surface of the sensor chip 200, and is made of, for example, a plastic material. The fixing member 150 also has a function of fixing the lancet needle 300, and a notch (not shown) for fixing the lancet needle 300 is formed on the lower surface thereof. Of course, the fixing member 150 and the support member 160 may be integrally formed.

  A flow path forming body 110 is provided on the front surface of the sensor chip 200. As will be described later, the flow path forming body 110 promptly guides body fluid (blood) flowing out from the puncture site to the sample introduction port 201. The illustrated flow path forming body 110 has a tube shape, and the inside of the tube is a flow path 111 through which blood flows. The flow path forming body 110 is formed in a so-called bellows shape, and can expand and contract in the flow path direction. The flow path forming body 110 does not need to return to its original shape by its restoring force, and does not need to have elasticity. This is because the restoring force generating member 130 restores the compressed flow path forming body 110. Of course, the flow path forming body 110 may have a restoring force. Moreover, since it is necessary to expand and contract in the flow path direction, it is preferable that the thickness (thickness) is thin. If the wall thickness is thin, the force required for compression and expansion becomes small, so that the mechanism for causing the needle integrated sensor 100 (sensor body 10) to collide can be made small. Moreover, the pain at the time of a collision becomes small. As long as these functions are satisfied, the material is not particularly limited, and may have a slight rigidity. However, a material having high rigidity increases the force required for compression and extension, and is not preferable. Further, the flow path forming body 110 is preferably made of a material that does not adversely affect the measurement result due to the eluted components. As such a material, for example, a polymer material used as an artificial blood vessel can be preferably used. Examples of such a polymer material include fluororesins such as expanded polytetrafluoroethylene and polyesters such as Dacron (trade name). Of course, there are measurement items that do not affect the measurement results, and when these items are targeted, polymers such as polyethylene, polystyrene, polypropylene, and polyethylene terephthalate can be used.

  The flow path forming body 110 is provided so that body fluid does not leak from the flow path 111 to the outside. For this purpose, for example, a base 140 made of synthetic resin or the like is provided on the front surface of the sensor chip 200, and the support member that holds the sensor chip 200 is embedded in the base 140 at the end of the flow path forming body 110. The method of fixing directly to the front surface of 160 or the fixing member 150 with an adhesive is mentioned. At this time, as shown in the figure, it is preferable that a through hole 141 is provided in the base 140 and the outer peripheral surface of the flow path forming body 110 is bonded to the inner peripheral surface thereof.

  A contact stabilizing member 120 is attached to the distal end portion of the flow path forming body 110 so that the distal end opening stably contacts the puncture target surface, that is, the skin surface. The material of the contact stabilizing member 120 is not particularly limited, but is a material that comes into contact with the skin in a stable and soft manner, for example, a slightly sticky resin material, specifically a thermosetting silicone rubber. Thermoplastic styrene rubber (for example, Septon (trade name)) is preferable.

  In the illustrated example, the outer peripheral surface of the flow path forming body 110 is bonded to the inner peripheral surface of the through-hole 121 provided in the contact stabilizing member 120, but depending on the attachment method, blood may be in contact with the contact stabilizing member 120. There is a possibility of contact. Further, the contact stabilizing member 120 needs to have a certain degree of rigidity, and also needs adhesiveness with the flow path forming body 110. In consideration of this, the fluororesin material used as the artificial blood vessel is preferable. However, the contact stabilizing member 120 using a fluororesin is unstable in contact with the skin, and there is a possibility that the position is displaced after the collision and it is difficult to sufficiently distribute the blood to the flow path 111. In this case, for example, as shown in FIG. 4, a contact stabilizing member 120 provided with a non-slip member 121 protruding on the surface is used. Moreover, you may use the contact stabilization member 120 which apply | coated the adhesive to the surface and improved adhesiveness.

  The lancet needle 300 has a needle tip that is positioned in the flow path forming body 110 when no force is applied, and a contact stabilizing member 120 that connects the flow path 111 when the needle tip collides with the puncture target surface, that is, the skin. It is provided to protrude slightly from the front.

  Between the base 140 and the contact stabilizing member 120, two restoring force generating members 130 made of leaf springs are provided to face each other. The restoring force generating member 130 shown in the figure is produced by joining two leaf springs at the end portions between the base 140 and the contact stabilizing member 120, and generates a restoring force in the flow path direction. The restoring force generating member 130 is fixed to the contact stabilizing member 120 by embedding at least one of the end portions of the leaf spring that is not joined and becomes a free end, and is integrated with the contact stabilizing member 120. In addition, the other end of the remaining leaf spring is preferably fixed to the base 140. Fixing at least one end of the contact stabilizing member 120 not only restores the compressed flow path forming body 110 to its original shape, but also functions to correctly compress the flow path forming body 110 in the flow path direction. The restoring force generating member 130 is not particularly limited in configuration as long as it fulfills these functions. A leaf spring is preferable from the viewpoint of small size and light weight, but a string spring may be used.

  The needle-integrated sensor 100 is provided as a sensor body 10 mounted on a sensor body 20 having a substantially cylindrical shape as shown in FIG. The sensor body 20 is used for mounting on the device body 2. Inside, a connector 21 for electrically connecting a terminal 212 of the sensor chip 200 and a measurement circuit (not shown) of the device main body 2 is provided. In addition, the rear end side of the sensor body 20 is a cylindrical drive spring mounting portion 22 having an outer diameter smaller than that of the front end side of the body.

  The sensor 10 having the flow path forming body 110 is attached to the device body 2 by inserting the vicinity of the base end of the wing portion 161 into the guide slit 4 of the device body 2 (see FIG. 5). The device main body 2 has a puncture mechanism for puncturing the mounted sensor body 10 against the skin, a conversion circuit for converting an electromotive voltage generated in the sensor chip 200 into a measured value, and a display mechanism for displaying the measured value. (Not shown). The puncture mechanism is constituted by a spring mechanism, for example. The spring mechanism includes a drive spring 31 provided at the rear portion of the sensor body 10 and a holding mechanism that holds the drive spring 31 in a compressed state and releases the hold state by the drive button 3. The drive spring 31 is attached to the sensor body 20 so that the drive spring mounting portion 22 is inserted into a part of the distal end side, and the other end is pressed into the wall surface 22 at a predetermined position of the device body 2 in the device body 2. Stored. Further, the illustrated drive spring 31 is not fixed to the device main body 2, and can move with the natural length when the contracted drive spring 31 returns to the natural length. One end of the drive spring 31 may be fixed to the device body 2 (for example, the wall surface 24).

  The holding mechanism includes a hook fixing recess 25 formed in the sensor body 20, a hook member 26 interlocking with the drive button 3, and a holding spring 27. The holding spring 27 urges the drive button 3 upward, and locks the hook 28 provided at the tip of the hook member 26 in the recess 25. When the sensor body 10 is inserted into the device body 2, the hook 28 at the tip of the hook member 26 engages with the recess 25 and holds the drive spring 31 in a compressed state. Next, when the drive button 3 is pressed, the hook 28 is removed from the recess 25 and the drive spring 31 is released. As a result, the sensor body 10 jumps forward with a strong force. As a result, the needle-integrated sensor 100 that has collided with the skin overcomes the restoring force of the restoring force generating member 130 as shown in FIG. Thereafter, while the contact stabilizing member 120 is kept in contact with the skin, the lancet needle 300 is detached from the skin by the restoring force of the restoring force generating member 130, and the blood flowing out from the skin fills the flow path 111. Thus, the blood is sufficiently distributed to the sample inlet 201.

  Thus, since the flow path forming body 110 that secures the flow path 111 is formed of a bellows structure that expands and contracts in the flow path direction, a rigid material such as a fluororesin can be used. For this reason, the selection range of the material is widened, and the material can be selected without affecting the measurement result.

  Further, since the flow path forming body 110 is restored by the restoring force generating member 130, the flow path forming body 110 itself does not require a restoring force, and the flow path forming body 110 can be configured in a thin tube shape. For this reason, the restoring force generated can be weakened. As a result, the driving force of the puncture mechanism for causing the needle integrated sensor 100 to collide can be reduced, which contributes to the downsizing of the sensor device. Further, since the collision force is reduced, the pain caused by the collision is reduced.

It is the schematic perspective view which fractured | ruptured partially the sensor body provided with the needle | hook integrated sensor of this invention. It is the schematic explanatory drawing which expanded a part of sensor body. It is a schematic perspective view of the sensor chip used for a needle integrated sensor. It is the schematic explanatory drawing which expanded a part of sensor body provided with the needle integrated sensor which is another embodiment. It is an external view of a sensor device to which a needle integrated sensor is attached. It is a schematic internal structure figure of the sensor device with which the needle | hook integrated sensor was mounted | worn. It is operation | movement explanatory drawing of a needle | hook integrated sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sensor device 2 Device main body 3 Drive button 4 Guidance slit 10 Sensor body 20 Sensor body 21 Connector 22 Drive spring mounting part 25 Recess 26 Hook member 27 Holding spring 28 Hook 31 Drive spring 100 Needle integrated sensor 110 Flow path formation body 111 Flow path 120 Contact stabilizing member 122 Antiskid member 130 Restoring force generating member 140 Base 150 Fixing member 160 Support member 161 Wing part 200 Sensor chip 201 Sample inlet 210 Substrate 220 Cover 221 Reagent layer 230 Sample space 240 Adhesive layer 300 Lancet needle

Claims (9)

  It has a sensor chip, a lancet needle fixed to one end of the sensor chip, and a flow path forming body made of a bellows structure that expands and contracts in the flow path direction provided at the one end of the sensor chip. Needle integrated sensor.   The needle integrated sensor according to claim 1, wherein the flow path forming body includes a contact stabilizing member for a puncture target surface.   The needle integrated sensor according to claim 1, further comprising a restoring force generating member that restores the contracted flow path forming body to an original shape.   The flow path forming body includes a restoring force generating member for restoring the contracted flow path forming body to an original shape, and a contact stabilizing member for a puncture target surface integrated with the restoring force generating member. The needle integrated sensor according to 1.   The needle-integrated sensor according to any one of claims 2 to 4, wherein the contact surface of the contact stabilizing member has anti-slip means.   The needle-integrated sensor according to claim 5, wherein the anti-slip means is a protrusion.   The needle-integrated sensor according to any one of claims 5 and 6, wherein the anti-slip means is application of an anti-slip agent.   The needle integrated sensor according to any one of claims 3 to 7, wherein the restoring force generating member is a leaf spring.   The needle integrated sensor according to any one of claims 1 to 8, wherein the flow path forming body is made of a fluororesin.

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