WO2010050350A1 - Bodily fluid collecting device and puncture needle attaching/detaching device used for same - Google Patents

Abstract

A bodily fluid collecting device (1) comprises: a piston (40) having a puncture needle (30) connected to the tip of the piston, the puncture needle (30) being used to puncture the skin of a person being tested and having a capillary tube structure for collecting bodily fluid oozing out of the punctured skin; a puncture spring (50) having a first spring constant which can eject the piston (40) in the puncturing direction to puncture the skin of the person by the puncture needle (30) and making contact with the rear end of the piston (40); a return spring (60) having a second spring constant which is less than the first spring constant and repelling the piston (40) in the direction opposite the puncturing direction; a stop spring (70) having a third spring constant which is less than the first spring constant and extending in the puncturing direction to stop the piston (40); a puncture button (80) for locking the piston (40) having been moved in the direction opposite the puncturing direction against the pressing force of the puncture spring (50) and ejecting the piston (40) by a release operation; and a housing (10) for containing the piston (40), the puncture spring (50), the return spring (60), the stop spring (70), and the puncture button (80).  The housing (10) is provided with an engaging section (90) for restricting movement of the piston (40) so that the piston (40) does not move in the puncturing direction from a predetermined position when the puncture spring (50) extends.  The puncture needle (30) punctures the skin of the person by extension of the puncture spring (50), is retracted from a punctured portion by a repelling action of the return spring (60), and, when the pressing force of the stop spring (70) and the repelling force of the return spring (60) are substantially in equilibrium with each other, is held at a position at which the tip of the puncture needle (30) makes contact with the oozing bodily fluid.

Description

Body fluid collecting device and puncture needle attaching / detaching member used in this device

The present invention relates to a body fluid collecting device and a puncture needle attaching / detaching member used in the device. More specifically, a humor sampling device that punctures the skin of a subject and collects bodily fluids erupted from the puncture site, and a puncture needle attachment / detachment used to attach a puncture needle to this device or remove a puncture needle from the device It relates to members.

There is a portable body fluid collecting device that punctures a subject's skin with a puncture needle and measures a component in body fluid such as blood that springs out. For example, diabetic patients are encouraged to regularly measure their own blood glucose fluctuations for self-management, and for this purpose, a puncture mechanism with a puncture needle that can be advanced and retracted, and Various body fluid collection devices having a measurement mechanism for measuring glucose concentration have been proposed.

For example, Patent Document 1 discloses a puncture device that uses two coil springs arranged in series to face each other as a puncture needle advance mechanism and retract mechanism. Specifically, this Patent Document 1 discloses a first coil spring that advances a puncture needle from a predetermined reference position toward a puncture site on the skin, and a first coil spring that punctures the skin with the first coil spring. A two-coil spring and a small protruding piece acting as a stopper for stopping the puncture needle at a predetermined puncture operation end position are provided.

This small protruding piece engages with the tip of the first stop lever provided in the housing when the puncture needle retracts after puncturing, and stops the movement of the plunger provided with the puncture needle. That is, in the puncture device described in Patent Document 1, the puncture operation end position of the plunger is defined by the positional relationship between the small protruding piece and the tip. The puncture operation end position is defined such that the tip of the puncture needle comes into contact with the blood that has flowed out of the skin, and blood is introduced into the measurement mechanism using the capillary structure of the puncture needle.

JP 2007-54407 A

However, in the puncture device described in Patent Document 1, the puncture operation end position of the plunger provided with the puncture needle is defined by the engagement between the small protruding piece and the tip, and the tip of the puncture device that contacts the skin and the puncture The positional relationship with the tip of the needle is fixed. The puncture device presses the tip of the puncture device against the skin of the subject during use, and punctures the skin raised in the opening formed at the tip with a puncture needle. It depends on how the puncture device is pressed during measurement. Therefore, if the distance between the raised top of the skin and the tip of the puncture needle is large, it is necessary to spout a lot of blood before the tip of the puncture needle comes into contact with blood. On the other hand, if the distance between the tip of the puncture needle and the tip of the puncture device is set to be small in order to reduce the amount of blood flowing out, in the case of a subject with a large amount of skin swell, the puncture needle is not withdrawn from the skin surface. There is a risk of burden.

The present invention has been made in view of such circumstances, and reduces the burden on the subject and can reduce the amount of collected body fluid, and the puncture needle attaching / detaching member used for the device The purpose is to provide.

The bodily fluid collecting device of the present invention punctures the skin of a subject, and a piston having a puncture needle having a capillary structure for collecting bodily fluid that springs out from the punctured skin,
A puncture spring that has a first spring constant capable of firing the piston in the puncture direction and puncturing the skin of the subject with the puncture needle;
A return spring having a second spring constant that is smaller than the first spring constant and repelling the piston in a direction opposite to the puncturing direction;
A third spring constant that is smaller than the first spring constant, and a stop spring that stops the piston by extending in the puncturing direction;
A puncture button that locks the piston moved in the direction opposite to the puncture direction against the urging force of the puncture spring, and fires the piston by an opening operation;
A body fluid collecting device comprising the piston, a puncture spring, a return spring, a stop spring, and a housing that accommodates a puncture button,
The housing is provided with a locking portion for restricting the movement of the piston so that the piston does not move in a puncturing direction from a predetermined position when the puncture spring is extended,
The puncture needle punctures the subject's skin by the extension of the puncture spring, the puncture needle is withdrawn from the puncture site by the repulsion of the return spring, and the pressing force of the stop spring and the repulsive force of the return spring are substantially balanced. Accordingly, the tip of the puncture needle is configured to be held at a position in contact with the bodily fluid that springs out.

In the body fluid sampling device of the present invention, the advancing operation and the retreating operation of the puncture needle are performed using three springs, that is, a puncture spring, a return spring, and a stop spring. Specifically, the puncture needle is advanced in the puncture direction by extension of the puncture spring compressed by the attachment of the puncture needle to puncture the subject's skin, and then the puncture needle is moved by repulsion of the return spring compressed by the puncture operation. Remove from the puncture site. Thereafter, the tip of the puncture needle is held at a position in contact with the bodily fluid that springs out due to a substantial balance between the repulsive force of the return spring and the pressing force of the stop spring. More specifically, the balance between the total repulsion force of the return spring and the reaction force received from the skin (force in the anti-puncture direction) and the pressing force (force in the puncture direction) by the stop spring (the puncture spring is The tip of the puncture needle is held at a position in contact with the bodily fluid that springs out by returning to the free length and applying no force to the piston.

Thus, in the body fluid sampling device of the present invention, it is defined that the tip position of the puncture needle comes into contact with the body fluid that swells regardless of the skin swell state of the subject, so that measurement can be performed with a small amount of body fluid, Moreover, since the puncture needle can be reliably withdrawn from the skin of the subject, the burden on the subject can be reduced.

The puncture needle attaching / detaching member of the present invention is used in a body fluid collecting device having a piston having a fitting mechanism for fixing the puncture needle at the tip, and the puncture needle before or after use is fitted to the piston. It is characterized by having an injector part that can be attached to and detached from the mechanism.

According to the body fluid sampling device of the present invention, it is possible to reduce the burden on the subject and reduce the amount of body fluid to be ejected.

It is a perspective explanatory view of a blood sugar level measuring device which is one embodiment of a body fluid sampling device of the present invention. It is the perspective view which looked at the blood glucose level measuring apparatus shown by FIG. 1 from the other direction. It is principal part cross-sectional explanatory drawing at the time of blood collection of the blood glucose level measuring apparatus shown by FIG. It is a principal part disassembled perspective view at the time of blood collection of the blood glucose level measuring apparatus shown by FIG. It is a principal part longitudinal cross-sectional view at the time of blood collection of the blood glucose level measuring apparatus shown by FIG. It is a perspective view of the puncture needle used for the blood glucose level measuring apparatus shown by FIG. It is a perspective view of the needle holder which is one Embodiment of the puncture needle attaching / detaching member of this invention. FIG. 8 is a plan view of the needle holder shown in FIG. 7. FIG. 8 is a bottom view of the needle holder shown in FIG. 7. FIG. 9 is a cross-sectional view taken along line AA in FIG. It is a perspective view of the injector part with which the protective cap was covered. It is front explanatory drawing of the state which mounted | wore the cap with the blood guard. It is perspective explanatory drawing just before mounting | wearing a puncture needle with a piston. It is perspective explanatory drawing of the state which inserted the puncture needle in the piston. It is perspective explanatory drawing of the state which pulls out an injector part from a piston after puncture needle insertion. It is a perspective explanatory view just before attaching an injector part to a piston at the time of puncture needle removal. It is perspective explanatory drawing of the state which inserted the injector part in the piston. It is a perspective explanatory view in the state where an injector part holding a puncture needle is pulled out from a piston. It is perspective explanatory drawing of the state which covered the protective cap on the injector part holding the puncture needle after use. It is principal part cross-sectional explanatory drawing of the blood glucose level measuring apparatus of the state which is not mounting | wearing with the puncture needle. It is principal part cross-sectional explanatory drawing of the blood glucose level measuring apparatus of the state with which the puncture needle was mounted | worn. It is principal part cross-sectional explanatory drawing of the blood glucose level measuring apparatus of the state which is blood-collecting after puncture. It is explanatory drawing of the blood glucose level measuring apparatus of the state with which the puncture needle was mounted | worn. It is explanatory drawing of a blood glucose level measuring apparatus when a puncture needle is fired and a subject's skin is punctured. It is explanatory drawing of the blood glucose level measuring apparatus of the state which is blood-collecting after puncture. It is a figure showing the behavior of the puncture needle tip at the time of puncture.

Hereinafter, embodiments of a body fluid collecting device of the present invention and a puncture needle attaching / detaching member used in the device will be described in detail with reference to the accompanying drawings.

[overall structure]
First, an overall configuration of a blood sugar level measuring device that is a body fluid sampling device according to an embodiment of the present invention will be described. 1 and 2 are perspective views of the blood glucose level measuring apparatus 1, FIG. 3 is a cross-sectional explanatory view of the main part of the blood glucose level measuring apparatus 1 shown in FIG. 1 during blood collection, and FIG. FIG. 5 is an exploded perspective view of the main part of the blood sugar level measuring apparatus 1 shown in FIG. 5 during blood collection, and FIG. 5 is a vertical sectional view of the main part of the blood sugar level measuring apparatus 1 shown in FIG. In FIG. 4, the puncture needle is not attached to the blood glucose level measuring device 1, but in FIG. 1 (the puncture needle is not shown), FIG. 2 (the puncture needle is not shown), FIG. 3, and FIG. Has been.

The blood glucose level measuring device 1 is a device that punctures the skin of a subject and measures / displays the glucose concentration in the blood that flows out from the puncture site, and has a generally pen-shaped shape as a whole so that the subject can easily carry it. Yes. The blood glucose level measuring device 1 is one in which elements such as a piston and a spring described later are accommodated in a pen-shaped housing 10 made of a synthetic resin. The housing 10 includes a housing body 10 a and a fixing ring 12 described later. A cap 20 is provided at the distal end portion of the fixing ring 12 constituting the distal end portion of the housing 10. A clip 21 is provided on the rear side end of the housing main body 10a to be configured so that the blood glucose level measuring device 1 is inserted into a subject's pocket or the like. Further, on the outer surface of the housing main body 10a, there are provided a display unit 22 for displaying measurement values, date, time, and the like, and operation buttons 23a, 23b for instructing power on / off and measurement start. A puncture button pressing portion 25 described later is disposed in an opening 24 formed on the outer surface of the front end side of the housing body 10a. 1 and 2, reference numeral 26 denotes a blood guard for preventing blood from adhering to the housing 10 and details will be described later.

The cap 20 is made of a transparent synthetic resin such as polycarbonate, and as shown in FIG. 4, has a substantially short cylindrical shape with one end portion being reduced in diameter toward the tip side. On the inner peripheral surface on the other end side of the cap 20, a female screw 20 a that engages with the male screw 11 formed at the tip of the fixing ring 12 is formed. By screwing the female screw 20a with the male screw 11 of the fixing ring 12, the cap 20 can be attached to the fixing ring 12, that is, the housing 10, and the depth at which the cap 20 is screwed into the fixing ring 12 is adjusted. The distance by which the puncture needle protrudes from the distal end surface of the cap 20 can be adjusted.

Also, a blood guard 26 is attached to the opening 20b on one end side of the cap 20 to prevent blood spilled from the skin of the subject from adhering to the cap 20 or the fixing ring 12. The blood guard 26 is also made of a transparent synthetic resin such as polycarbonate, like the cap 20, and has a needle insertion opening 26a through which a needle holder, which will be described later, to which a puncture needle is attached can be inserted. It consists of a disk body 26b. In addition, as shown in FIG. 12, a pair of locking pieces 20c are attached to one surface of the disk body 26b (the surface on the side attached to the opening 20b of the cap 20) with the needle insertion port 26a interposed therebetween. The blood guard 26 is attached to the cap 20 when the locking piece 20c is locked to the periphery of the opening 20b of the cap 20 so as to face each other. Further, a pair of convex portions 26d are provided on the outer edge portion of the disc body 26b at positions facing each other. The blood guard 26 can be easily removed from the cap 20 by grasping the convex portion 26d. The blood guard 26 is a disposable type and is discarded together with the puncture needle 30 every time measurement is completed.

In the housing 10, a piston 40 to which the puncture needle 30 is connected at the tip, a puncture spring 50 for firing the piston 40 in the puncture direction, a return spring 60 for repelling the piston 40 in the direction opposite to the puncture direction, A fixed spring provided with a stop spring 70 for stopping the piston 40, a puncture button 80 for firing the piston 40 by an opening operation, and the return spring 60 and a locking portion 90 for restricting movement of the piston 40 in the puncture direction. An annular stopper 100 slidable with respect to the ring 12, the piston 40, and a microswitch 13 for detecting attachment of the puncture needle 30 to a predetermined location are accommodated. Although not shown, a battery for supplying power necessary for measurement operation and display of the measurement result, and a control unit for controlling the calculation of the detection result and the display on the display unit 22 are accommodated in the housing 10. Has been.
Next, each element in the housing 10 will be described. In this specification, the “tip side” means the side on which the puncture needle 30 is mounted, and the “rear side” means the opposite side, that is, the clip. The side on which 21 is provided.

The fixing ring 12 is a member that constitutes the housing 10 together with the housing body 10a as described above, and is connected to the end of the housing body 10a on the front end side. The fixing ring 12 has a substantially cylindrical shape, and includes a small-diameter portion 12a on the front end side and a large-diameter portion 12b on the rear side.

An opening 12a2 through which the piston 40 can pass is formed on the distal end side end surface 12a1 of the small diameter portion 12a. Further, an inner wall 12a3 coaxial with the small diameter portion 12a is erected on the periphery of the opening 12a2 toward the rear side. The end portion on the front end side of the return spring 60 is accommodated in the annular space 12a4 between the inner wall 12a3 and the small diameter portion 12a. The male screw portion 11 is formed on the outer peripheral surface on the distal end side of the small diameter portion 12a.

A pair of passages 12b2 that allow the guide piece 102 (see FIG. 3) of the stopper 100 to move are formed on the inner surface 12b1 of the large diameter portion 12b so as to face each other. Further, a notch 12b3 that receives the peripheral wall 24a of the opening 24 in which the pressing portion 25 is disposed when the fixing ring 12 is connected to the housing body 10a is formed at the rear side end of the large diameter portion 12b.

The piston 40 is formed of an elongated cylindrical body made of a synthetic resin, and a first collar portion 41 having an abutting surface 41a with which an end portion on the rear side of the return spring 60 abuts on an outer peripheral surface on the front end side thereof. Is formed. Further, a second collar portion 42 having an abutting surface 42 a with which the end portion on the distal end side of the puncture spring 50 abuts is formed on the outer peripheral surface on the rear side of the piston 40. An elongated notch 43 is formed along the axial direction on the outer peripheral surface between the first collar portion 41 and the first collar portion 41, and from the short side of the front end side of the notch 43 to the rear side. A swing piece 44 is extended toward the end.

At the tip of the swing piece 44, that is, at the end on the rear side, a locking portion 45 protruding in the radially outward direction is formed, and the rear side of the locking portion 45 is a chamfered inclined surface 45a. Yes. Further, the front surface 45 b of the locking portion 45 is a plane that is substantially orthogonal to the moving axis of the piston 40. Since the swing piece 44 is made of synthetic resin and has a cantilever shape, it can be elastically deformed in a direction perpendicular to the axis of the piston 40. Using this elastic deformation, a firing operation of the piston 40 by a puncture button 80 described later is performed.

In addition, a holding portion 46 for holding the inserted puncture needle 30 is provided inside the piston 40 on the distal end side, and the holding portion 46 has a pair of punctures provided with a pawl portion 47a on the distal end side. A needle fixing piece 47 is provided (see FIG. 13). The pair of puncture needle fixing pieces 47 are disposed so as to sandwich the inserted puncture needle 30 in the width direction, and the respective pawl portions 47a are formed to face each other. Further, between the pair of puncture needle fixing pieces 47, an apparatus-side electrode 48 that is in contact with the sensor electrode portion 35 (see FIG. 6) provided on the puncture needle 30 is disposed. The electrode 48 is made of a spring body in order to reliably contact the sensor electrode portion 35 of the inserted puncture needle 30.

The puncture spring 50 is disposed so as to be wound around the outer peripheral surface of the piston 40 in the vicinity of the end on the rear side of the piston 40. The end on the front end side of the puncture spring 50 is in contact with the contact surface 42a of the second collar portion 42 of the piston 40, while the end on the rear side is the front end of the partition plate 14 formed inside the housing 10. Abuts on the side surface 14a. The end portion on the front end side of the puncture spring 50 can be separated from the contact surface 42a, but the end portion on the rear side is fixed to the surface 14a. An opening 14b through which the piston 40 can pass is formed in the center of the partition plate 14.

The return spring 60 is disposed so as to be wound around the outer peripheral surface of the piston 40 in the vicinity of the end portion on the front end side of the piston 40. The end portion on the front end side of the return spring 60 abuts on a fixing ring 12 described later, while the end portion on the rear side abuts on the abutment surface 41 a of the first collar portion 41 of the piston 40.

The stop spring 70 is disposed so as to be wound around the outer peripheral surface between the first collar portion 41 and the second collar portion 42 of the piston 40. The end portion on the front end side of the stop spring 70 abuts on an end surface on the rear side of the stopper 100 described later, while the end portion on the rear side is a spring accommodating portion 15 formed in the housing body 10a (see FIGS. 3 to 4). Is housed inside. The spring accommodating portion 15 includes a thin distal end portion 10a1 of the housing main body 10a, and an inner wall 10a2 formed coaxially with the distal end portion 10a1 inside the distal end portion 10a1 (the rear side of the inner wall 10a2). The end portion is connected to the inner surface of the housing main body 10a). The end on the rear side of the stop spring 70 is accommodated in the spring accommodating portion 15 in order to avoid interference with the locking portion 45 of the swing piece 44. The fixing ring 12 is fixed to the housing main body 10a by fitting the rear side end of the fixing ring 12 to the outer peripheral surface of the housing main body 10a including the outer peripheral surface of the front end 10a1.

As shown in FIG. 4, the puncture button 80 is made of a substantially band-plate-like member, and a pressing portion 25 that can be pressed by the subject is formed at the end on the tip side. The pressing portion 25 is disposed so as to be located in the opening 24 of the housing body 10a. On the inner wall of the housing body 10a defining the opening 24, an engaging portion 16 having an inclined surface 16a inclined at substantially the same angle as the inclined surface 45a of the locking portion 45 of the swing piece 44 is formed. . A surface 16b on the rear side of the engaging portion 16 is a flat surface that is substantially orthogonal to the moving axis of the piston 40.

An operation piece 80a is erected on the inner side surface of the puncture button 80 in the radially inward direction. The distal end surface 80a1 of the operation piece 80a comes into contact with the upper surface 45c of the locking portion 45 of the swing piece 44 in a state where the puncture needle 30 before use is mounted on the blood glucose level measuring device 1. When the subject presses the puncture button 80, the locking portion 16 is provided between the inner surface of the pressing portion 25 of the puncture button 80 so as to allow movement of the operation piece 80a to the inner side. The clearance is maintained.

The locking portion 90 is a portion that plays a role of regulating the movement of the piston 40 so that the piston 40 does not move in the puncturing direction from a predetermined position when the puncture spring 50 is extended. A step portion formed on the inner surface of the small diameter portion 12 a of the fixing ring 12 constitutes the locking portion 90. In the present embodiment, the abutment surface 41a of the first collar portion 41 of the piston 40 abuts on the locking portion 90 formed of a stepped portion, so that the movement of the abutment piston 40 in the puncture direction is restricted. The positional relationship between the distal end of the puncture needle 30 and the housing 10 when it is most extended is fixed, and by adjusting the depth at which the cap 20 is screwed into the fixing ring 12, The positional relationship with the position of the tip of the puncture needle 30 when it is most extended, that is, the puncture depth by the puncture needle 30 can be adjusted.

The stopper 100 is made of an annular member that is slidable with respect to the piston 40, and is disposed coaxially with the piston 40. The stopper 100 includes an annular stopper body 101, a pair of guide pieces 102 extending from the outer edge portion of the stopper body 101 to the distal end side, and a stop wall 103 projecting from the inner edge of the stopper body 101 toward the distal end side. It consists of and. The guide piece 102 is movable in the passage 12b2 of the large-diameter portion 12b of the fixing ring 12, and the tip 102a is configured to be in contact with the rear side end portion 20c of the cap 20 screwed into the fixing ring 12. ing. In the present embodiment, the rear side end portion 20c of the cap 20 functions as a stationary portion that receives the stopper 100 in order to restrict the puncture needle 30 from moving beyond a predetermined puncture depth by extension of the stop spring 70. is doing. Further, the distal end 103 a of the stop wall 103 is configured to be able to contact the rear side surface 41 b of the first collar portion 41 of the piston 40.

[Puncture needle removable member]
Next, the puncture needle attaching / detaching member used in the blood glucose level measuring apparatus 1 described above will be described.
6 is a perspective view of the puncture needle 30 used in the blood sugar level measuring device 1. FIG. 7 is a diagram illustrating the puncture needle 30 shown in FIG. It is a perspective view of the injector part 110 which is a puncture needle attaching / detaching member used for removing. 8 and 9 are a plan view and a bottom view, respectively, of the injector unit 110 shown in FIG. 7, and FIG. 10 is a cross-sectional view taken along line AA of FIG.

First, the puncture needle 30 will be described. As shown in FIG. 6, the puncture needle 30 includes a substantially strip-shaped main body portion 31 made of a synthetic resin such as polylactic acid, and polylactic acid of the same material provided on one end side of the main body portion 31. And a needle portion 32 made of a synthetic resin. In the present embodiment, a sensor unit (not shown) is built in the main body unit 31. The needle part 32 has a capillary structure capable of introducing the blood into the sensor part by touching the blood flowing from the skin of the subject to the tip. Specifically, a flow path composed of a groove (width 0.1 mm, depth 0.05 mm) is formed in the needle portion 32, and blood that touches the tip of the needle portion 32 is caused by capillary action. The sensor part connected to the flow path of the part 32 is introduced. A signal corresponding to the glucose concentration in the blood of the subject detected by the sensor unit is provided on the other end side of the main body 31, and the piston in contact with the sensor electrode unit 35. The data is transmitted to a control unit (not shown) provided in the housing 10 via the 40 electrodes 48.

A first protrusion 33 used when the puncture needle 30 is attached to the piston 40 is formed at a position facing the substantially central portion of both side edges of the substantially strip-shaped main body 31. The first protrusion 33 is formed so as to protrude in a direction perpendicular to the longitudinal direction of the main body 31 and parallel to the surface 31 a of the main body 31. In addition, a second protrusion 34 that is used when the puncture needle 30 is removed from the piston 40 is erected from the surface 31 a at the center in the width direction of the surface 31 a of the main body 31.

As shown in FIG. 7, the injector unit 110 has a pre-use fitting mechanism 112 for attaching the puncture needle 30 before use to the piston 40 on one side with the substantially disc-shaped gripping portion 111 as a boundary. And a post-use fitting mechanism 113 for removing the used puncture needle 30 from the piston 40 on the other side.

The pre-use fitting mechanism 112 has a pre-use storage part 114 into which the puncture needle 30 can be inserted from the needle part 32 side. FIG. 11 shows a state where the puncture needle 30 before use is accommodated in the pre-use accommodation portion 114 of the pre-use fitting mechanism 112 and the puncture needle 30 is covered with a protective cap 115 made of a transparent synthetic resin. ing. The puncture needle 30 before use is handled in the state shown in FIG. 11 after sterilization.

Similarly to the pre-use fitting mechanism 112, the post-use fitting mechanism 113 also has a post-use accommodating portion 116 into which the puncture needle 30 can be inserted from the needle portion 32 side. Further, the post-use fitting mechanism 113 is a second engaging portion for engaging with the second protrusion 34 (first engaging portion) of the puncture needle 30 and removing the puncture needle 30 attached to the piston 40. An engagement piece 116a having a claw portion 116a1 at the tip is provided.

[Puncture / detachment operation of puncture needle]
Next, an attaching / detaching operation (attaching operation and removing operation) of the puncture needle 30 using the injector unit 110 will be described.

[Installation operation]
As shown in FIG. 11, the unused puncture needle 30 is usually covered with a transparent protective cap 115 and stored with the blood guard 26 sandwiched between the protective cap 115 and the grip portion 111. Has been. The puncture needle 30 is in a state where the needle portion 32 is accommodated in the pre-use accommodating portion 114 of the pre-use fitting mechanism 112.

(1) First, the puncture depth is set (see FIG. 4). The puncture depth can be adjusted by adjusting the length of screwing the cap 20 of the blood glucose level measuring device 1 into the fixing ring 12 as described above. If there is no change in the puncture depth, this step is omitted.
(2) Next, the puncture needle 30 with the protective cap 115 removed is inserted into the needle insertion port 26a through the blood guard 26 into the opening 20b of the cap 20, and the blood guard 26 is attached.

(3) Next, the puncture needle 30 is further pushed into the holding portion 46 of the piston 40 (see FIG. 13). In FIG. 13 and FIGS. 14 to 18 to be described later, the cap 20 and the blood guard 26 are not shown for easy understanding.
At this time, the piston 40 moves to the rear side against the urging force of the puncture spring 50 when the puncture needle 30 is pushed in, and the engagement portion 45 of the swing piece 44 is formed in the housing body 10a. The unit 16 engages with a small clicking sound.

In the process in which the puncture needle 30 is pushed into the holding portion 46 of the piston 40, the first protrusion 33 of the puncture needle 30 first comes into contact with the inner inclined surface 47b of the claw portion 47a of the puncture needle fixing piece 47, and this puncture needle fixing. Spread piece 47 outward. Thereafter, when the puncture needle 30 is further pushed in, the first protrusion 33 gets over the claw portion 47a of the puncture needle fixing piece 47 (see FIG. 14). As a result, the puncture needle fixing piece 47 returns to its initial shape due to elasticity, and the first protrusion 33 of the puncture needle 30 engages with the claw portion 47 a of the puncture needle fixing piece 47. At this time, the sensor electrode portion 35 of the puncture needle 30 is electrically connected to the electrode 48.

(4) Next, as shown in FIG. 15, by pulling out the injector section 110, the blood guard 26 is attached to the cap 20 and the puncture needle 30 is attached to the piston 40. Since the first protrusion 33 of the puncture needle 30 is engaged with the claw portion 47a of the puncture needle fixing piece 47, the puncture needle 30 is not easily removed by a normal puncture operation or the like.

[Removal operation]
When the puncture needle 30 is removed from the piston 40 after the measurement is completed, the post-use fitting mechanism 113 side of the injector unit 110 is used.
(1) First, the post-use fitting mechanism 113 of the injector unit 110 is inserted into the needle insertion port 26a of the blood guard 26, and the post-use fitting mechanism 113 is pushed into the holding portion 46 of the piston 40 until further abutting (see FIG. 16-17). Thereby, the claw portion 116a1 of the engagement piece 116a of the post-use fitting mechanism 113 gets over the second protrusion 34 of the puncture needle 30 and engages with the second protrusion 34.

(2) Next, the injector part 110 is pulled out from the piston 40. At this time, the engagement force between the claw portion 116 a of the engagement piece 116 and the second protrusion 34 of the puncture needle 30 is smaller than the engagement force of the claw portion 47 a of the puncture needle fixing piece 47 and the first protrusion 33 of the puncture needle 30. Therefore, the used puncture needle 30 can be removed from the piston 40 by pulling out the injector part 110 from the piston 40. The engagement force can be adjusted by, for example, changing the shape and size of the claw portion.

The extracted puncture needle 30 is held in the accommodating portion 116 of the injector unit 110, and the claw portion 116a of the engagement piece 116 and the second protrusion 34 of the puncture needle 30 engage with each other. Although it does not easily detach from 110, it is disposed of with a protective cap 115 for safety.
In the above-described puncture needle pull-out operation, the blood guard 26 attached to the cap 20 is locked to the first protrusions 33 and 33 of the puncture needle 30, so that the blood guard 26 is collected together with the puncture needle 30. The illustration is omitted to simplify the explanation. Then, the collected blood guard 26 is disposed of in a state of being sandwiched between the grip portion 111 and the first protrusion 33 of the puncture needle 30.

[Operating procedure]
Next, the operation procedure of the blood sugar level measuring apparatus 1 will be described.
FIG. 20 is a cross-sectional explanatory view of a main part of the blood sugar level measuring apparatus 1 in a normal state where no puncture needle is attached. In this state, the puncture spring 50 maintains a free length and is not biased. In other words, the biasing force by the spring is not applied to the piston 40. On the other hand, the return spring 60 and the stop spring 70 are both compressed.

(Puncture needle installed)
First, as shown in FIG. 21, when the puncture needle 30 is attached to the piston 40, the piston 40 moves to the rear side, and the contact surface 42 a of the second collar portion 42 of the piston 40 is at the distal end side of the puncture spring 50. The puncture spring 50 is compressed in contact with the end of the puncture spring. Further, the rear side surface 41b of the first collar portion 41 of the piston 40 comes into contact with the front end 103a of the stop wall 103 of the stopper 100 to move the stopper 100 to the rear side. Thereby, the stop spring 70 is compressed.

Further, due to the movement of the piston 40 toward the rear side, the inclined surface 45a of the locking portion 45 of the swing piece 44 of the piston 40 comes into contact with the inclined surface 16a of the engaging portion 16 of the housing body 10a, and the piston 40 is further moved to the rear portion. When it moves to the side, the rocking piece 44 is deformed inward by its elasticity, so that the locking part 45 gets over the engaging part 16, and the locking part 45 engages with the engaging part 16. As a result, the piston 40 is held at the firing standby position. Further, due to the movement of the piston 40 to the rear side, the rear side end surface of the piston 40 comes into contact with a contact (not shown) of the micro switch 13 disposed in the housing body 10a, whereby the piston 40 is predetermined. It is detected that the position setting is complete.

FIG. 23 is a diagram for mainly explaining the states of the three springs (puncture spring 50, return spring 60, and stop spring 70) when the puncture needle 30 is attached. In FIG. 23 and FIGS. 24 to 25 to be described later, the locking portion and the stationary portion are shown as a model for easy understanding. The locking portion 90 and the stationary portion in the embodiment described above are configured and The arrangement is different. As shown in FIG. 23, in the state where the puncture needle is set, the puncture spring 50 is in a compressed state, and a force in the puncture direction acts on the piston 40. The stop spring 70 is also in a compressed state, and a force in the puncture direction is applied to the piston 40. On the other hand, the return spring 60 is in a free length state, and no force is applied to the piston 40. The firing of the piston 40 is restricted by the puncture button 80. In FIGS. 23 to 25, S indicates a stationary part.

〔puncture〕
When the pressing portion 25 of the puncture button 80 is pressed by the subject, the locking portion 45 of the swing piece 44 is pushed inward by the operation piece 80a of the puncture button 80 and moves. As a result of the engagement with the engaging portion 16 of the housing body 10a being released, the piston 40 is fired in the puncturing direction. Then, the skin C of the subject is punctured by the puncture needle 30 attached to the tip of the piston 40. The movement of the piston 40 in the puncture direction is restricted by the surface 41a of the first collar portion 41 of the piston 40 hitting the locking portion 90 formed of a step portion formed on the inner surface of the small diameter portion 12a of the fixing ring 12. Is done.

At the time of puncturing, as shown in FIG. 24, the puncture spring 50 returns to a free length and does not act on the piston 40. In addition, the return spring 60 is pressed by the first collar portion 40 of the piston 40 moved in the puncturing direction to be in a compressed state, and acts on the piston 40 in the rear side direction. Further, the stop spring 70 is less compressed than when the puncture needle is attached, but is still in a compressed state, and exerts a force in the puncture direction on the piston 40. The stop spring 70 is configured to maintain a predetermined compressed state even during puncturing because the stopper 100 is restricted in movement in the puncturing direction by the stationary portion S formed by the rear side end portion 20c of the cap 20. Yes.

[Blood collection]
After the puncture, the puncture needle 30 returns to the rear side due to the reaction force from the skin C of the subject, and then the stop spring 70 and the return spring 60. An equilibrium state is maintained, and blood is collected from the puncture needle 30 in this equilibrium state (see FIG. 22).

In this equilibrium state, as shown in FIG. 25, the puncture spring 50 has a free length and does not act on the piston 40. Further, the stop spring 70 is in a compressed state, and acts on the piston 40 in the puncture direction. Further, the return spring 60 is in a compressed state, and acts on the piston 40 in the rear side direction. In the example shown in FIG. 25, the force F2 in the puncture direction of the stop spring 70, the force F3 in the rear side direction of the return spring 60, and the force F1 from the skin C are balanced (F1 + F2 + F3 = 0). The position of the tip of puncture needle 30 is defined. When the stopper 100 is in contact with the stationary part S, not the force from the skin C but the reaction force from the stationary part S of the stopper 100, the force F2 in the puncture direction of the stop spring 70, and the rear side direction of the return spring 60 The position of the tip of the puncture needle 30 is defined by the balance of the three forces. The stationary portion S is set at a position where the movement of the piston 40 in the puncturing direction is restricted within a range where the movement of the piston 40 in the puncturing direction is restricted by the locking portion 90. That is, the position of the stationary portion S is set so that the tip of the puncture needle 30 stops at a position on the rear side of the maximum puncture depth.

The spring constant (first spring constant) of the puncture spring 50 is larger than the spring constant (second spring constant) of the return spring 60 and larger than the spring constant (third spring constant) of the stop spring 70. Is set. For example, the first to third spring constants can be 1.1 N / mm, 0.17 N / mm, and 0.23 N / mm, respectively. By setting in this way, the tip of the puncture needle is positioned near the puncture site by balancing the force of the return spring 60 and the stop spring 70 after the puncture while ensuring a predetermined puncture needle depth (piston extension distance). It becomes possible to hold on.

FIG. 26 is a diagram showing the movement of the tip of the puncture needle during puncture, and shows the behavior of the puncture needle until the puncture needle comes to rest after puncture. In FIG. 26, the horizontal axis represents the passage of time after puncturing, and the vertical axis represents the position of the tip of the puncture needle from the reference position and the speed (X direction) of the puncture needle. Further, h represents the position of the subject's skin surface, and p represents the position when the puncture needle is most extended. Further, “X” indicates a puncturing direction, and “Y” indicates a direction orthogonal to the puncturing direction. As can be seen from FIG. 26, a substantially equilibrium state is reached in about 0.01 seconds after the puncture, and the tip of the puncture needle is maintained at a position close to the surface of the subject's skin C.

The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the attachment of the puncture needle 30 to the piston 40 is, for example, hemispherical in addition to the engagement by the claw portion (claw portion 47a of the puncture needle fixing piece 47 of the piston 40) and the projection (first projection 33 of the puncture needle 30). Other engaging means such as engagement between the convex portion of the convex portion and the concave portion corresponding to the convex portion shape can be used.

Similarly, the puncture needle 30 can be detached from the piston 40 in addition to the engagement by the claw portion (claw portion 116a of the engagement piece 116 of the injector portion 110) and the projection (second projection 34 of the puncture needle 30). For example, other engaging means such as engagement between a hemispherical convex portion and a concave portion corresponding to the convex shape can be used.

Further, for the engaging portion 90 that regulates the puncture depth of the piston 40, for example, a protrusion or a convex portion formed on the inner peripheral surface of the housing body 10a can be used as the engaging portion 90. It is not limited.

Claims (8)

A puncture needle having a capillary structure that punctures the skin of the subject and collects a bodily fluid that springs from the punctured skin,
A puncture spring that has a first spring constant capable of firing the piston in the puncture direction and puncturing the skin of the subject with the puncture needle;
A return spring having a second spring constant that is smaller than the first spring constant and repelling the piston in a direction opposite to the puncturing direction;
A third spring constant that is smaller than the first spring constant, and a stop spring that stops the piston by extending in the puncturing direction;
A puncture button that locks the piston moved in the direction opposite to the puncture direction against the urging force of the puncture spring, and fires the piston by an opening operation;
A body fluid collecting device comprising the piston, a puncture spring, a return spring, a stop spring, and a housing that accommodates a puncture button,
The housing is provided with a locking portion for restricting the movement of the piston so that the piston does not move in a puncturing direction from a predetermined position when the puncture spring is extended,
The puncture needle punctures the subject's skin by the extension of the puncture spring, the puncture needle is withdrawn from the puncture site by the repulsion of the return spring, and the pressing force of the stop spring and the repulsive force of the return spring are substantially balanced. Thus, the bodily fluid collecting device is configured so that the tip of the puncture needle is held at a position in contact with the bodily fluid that springs out. The bodily fluid collection device according to claim 1, wherein the puncture spring, the return spring, and the stop spring are arranged on the same axis parallel to the moving direction of the piston. The bodily fluid collecting device according to claim 1 or 2, wherein the puncture needle includes a bodily fluid analyzing sensor that comes into contact with the capillary structure. 4. The bodily fluid collecting device according to claim 1, wherein a fitting mechanism for fixing a puncture needle to the piston is provided at a tip of the piston. An annular stopper slidable with respect to the piston is disposed coaxially with the piston, and the stopper is provided to restrict the puncture needle from moving beyond a predetermined puncture depth by extension of the stop spring. The bodily fluid collecting device according to any one of claims 1 to 4, further comprising a stationary part for receiving the humor. A puncture needle attaching / detaching member used in the body fluid sampling device according to claim 4, further comprising an injector part for attaching / detaching a puncture needle before or after use to a fitting mechanism of the piston. The puncture needle attaching / detaching member according to claim 6, further comprising a substantially transparent protective cap that accommodates the puncture needle before or after use. The injector section includes a pre-use fitting mechanism for attaching a puncture needle before use to the piston, and a post-use fitting mechanism for removing the puncture needle after use from the piston. 8. The coupling mechanism according to claim 6, further comprising a second engagement portion that engages with a first engagement portion provided on the puncture needle and removes the puncture needle attached to the piston from the piston. Puncture needle attaching / detaching member.

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