JP5015699B2 - Puncture device - Google Patents

Description

  The present invention relates to a puncture apparatus that includes a needle body and punctures the skin by momentarily projecting the needle body.

  Diabetic patients are encouraged to perform routine self-management by measuring their own blood glucose fluctuations. The blood glucose level is measured by attaching a test paper impregnated with a reagent that develops color depending on the amount of glucose in the blood, supplying blood to the test paper to cause coloration, and optically determining the degree of coloration. A blood component measuring apparatus that obtains and displays a blood glucose level by measuring it has been put into practical use. A blood component measuring apparatus using an electrochemical sensor has also been put into practical use.

  When a patient collects his / her blood, a puncture device equipped with a puncture needle tip having a needle that can advance and retreat in the axial direction is used. The puncture needle tip is detachable from the puncture device, and a repulsive force is applied to the internal needle by an elastic body so that the needle protrudes instantaneously, so that the needle is skinned (for example, finger, palm, arm, earlobe, etc.) ) To bleed a minute amount of blood. After puncturing, the needle is retracted by a predetermined return mechanism.

  The puncture device is generally used with a puncture needle tip attached, and the puncture needle tip is discarded after use. Therefore, in hospitals, a large number of puncture needle tips are prepared according to the number of patients and the measurement frequency, but the number of puncture devices is relatively small. However, for example, when blood glucose levels are measured simultaneously for a large number of patients, the number of puncture devices is insufficient, and measurement may take time. Further, it is necessary to attach and detach the puncture needle tip to the puncture device every time measurement is performed, and a simpler puncture device is desired. Furthermore, in the hospital, when blood containing an infectious pathogen adheres to the puncture device, it is necessary to pay particular attention to infection to other patients and staff.

  From such a background, Patent Document 1 describes a simple disposable lancet integrated with a puncture needle tip. In such a disposable lancet, it is not necessary to attach or detach the puncture needle tip.

US Pat. No. 5,746,761

  In the disposable lancet described in Patent Document 1, an arm having a conical hole is pushed in a direction perpendicular to the axis, and the needle body is pushed out in the axial direction by the conical hole to perform puncturing. The arm further moves so that the conical hole passes through the axial position, and the needle body is pulled back by the spring and stored in the cylindrical hole of the arm.

  In such a disposable lancet, it is possible to pull out the needle after it is pushed out in conjunction with the movement of the arm, but the movement of the needle is basically converted to a right angle of the movement of the arm. In this case, the force that the person pushes the arm against the elasticity of the spring is transmitted to the needle body as it is and puncture is performed. Therefore, there is a case where the movement of the needle body is direct with respect to human finger operation, and the skin is elastically deformed due to the slow puncture speed of the needle body and sufficient puncture is not performed. Moreover, since the speed of puncture is slow, it is easy to feel pain, and there is resistance to pushing the arm further after the needle tip comes into contact with the skin, and it is difficult for the patient to accept.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a puncture device that can be reliably punctured and that is fast in operation and less painful.

  A puncture device according to the present invention includes a needle body including a needle and a hub that holds the needle, a case including a tip opening that guides the needle body in an axial direction thereof and the tip of the needle projects instantaneously. A part of the push rod which protrudes from the case in an initial state and is provided so as to be movable non-parallel to the axial direction of the needle body, and a first cam surface provided in the case, The push rod is slidably contacted with the end of the needle body by being pushed down, and is elastically deformed by slidingly contacting a part of the case with a second cam surface that pushes the needle body in the axial direction. And an elastic arm that presses the first cam surface while sliding on the first cam surface after passing through the portion, and elastically urges the push rod to move further.

  According to such a puncture device, the elastic arm is temporarily compressed by pushing down the push rod and then extends along the first cam surface, so that the needle body is automatically and vigorously pushed out by the elastic force of the elastic arm. Can do. Thus, reliable puncture is possible, and the operation is fast and pain is reduced. The puncture device has a simple configuration and is suitable for disposable use.

  The push rod has a recess with which an end of the needle body engages after the second cam surface passes through the central axis of the needle body, and an elastic body is provided between the needle body and the case. After the second cam surface has passed through the central axis, the elastic body may press the needle body in the direction of the recess. According to such a configuration, the needle body after the puncture is automatically pulled out and pain is further reduced, and the needle body and the push rod are engaged and fixed to each other and are not reused. .

  The push rod is provided in a hole opened in a side surface of the case, and at least a part of the elastic arm protrudes from the hole, and in an initial state, abuts on the hole of the case, and the push rod is connected to the needle body. It may be elastically biased in the protruding direction. According to such a configuration, the push rod can be prevented from falling into the case in the initial state.

  The step at one end of the second cam surface may abut against the lumen surface of the case in the initial state. According to such a configuration, the push rod can be prevented from coming out of the case in the initial state.

  The elastic arm may have an arcuate portion in a free end portion in a direction approaching the push rod. According to such a structure, it can transfer to an automatic operation | movement from the position which pushed the push rod moderately. By having not only a substantially straight portion but also an arc-shaped portion, the elastic arm becomes reasonably long and the push rod can be moved sufficiently.

  According to the puncture device of the present invention, the elastic arm is temporarily compressed by pushing down the push rod and then extends along the first cam surface, so that the needle body is automatically and vigorously pushed out by the elastic force of the elastic arm. be able to. Thus, reliable puncture is possible, and the operation is fast and pain is reduced. The puncture device according to the present invention has a simple configuration and is suitable for disposable use.

  Hereinafter, embodiments of the puncture apparatus according to the present invention will be described with reference to FIGS. Hereinafter, the arrow X1 direction after FIG. 1 is defined as the front (front end direction), and the X2 direction is defined as the rear (base end direction).

  As shown in FIGS. 1, 2, 3, and 4, the puncture device 10 according to this embodiment includes a case 12, a needle body 14 provided in the case 12, a protective cap 15, and a push rod 17. And have. The puncture device 10 can be made of resin (for example, polypropylene or polyethylene) or metal except for a needle 40 and a coil spring (elastic body) 46 described later. A distal end surface 12a having an appropriate area for contacting the skin is formed at the distal end of the case 12. On the lower surface of the case 12, a plurality of anti-slip protrusions 12b are provided.

  The case 12 is configured by combining two members, a rear portion 16 and a front portion 18. The front portion 18 has a substantially spindle shape with a tapered front portion, a substantially cylindrical shape with a rear portion, and has a lumen 22. The inner cavity 22 is provided with a cylindrical body 24 extending rearward from the distal end portion. The rear portion 16 is a lid that is attached to the rear of the front portion 18 and covers the lumen 22. On the upper surface of the case 12, a square hole 26 formed by a gap is provided between the rear portion 16 and the front portion 18. Guide grooves 26 a are provided on the left and right sides of the square hole 26.

  The cylindrical body 24 is provided with a hub passage 28 and a needle passage 30 communicating in the axial direction. The needle passage 30 has a tip opening 30a, and the rear thereof communicates with the hub passage 28. Needle passage 30 is narrower than hub passage 28. The lumen 22 communicates with the hub passage 28.

  As shown in FIG. 5, the case 12 is manufactured by molding two symmetrical members 32, 32 on the left and right sides with a short bending member 34, bending the bending member 34, and bringing the members 32, 32 into contact with each other. May be.

  As shown in FIG. 2, the needle body 14 includes a needle 40 and a hub 42 that holds the needle 40. The hub 42 has a front column 42a partially inserted into the hub passage 28 and the needle passage 30, and a tag 42b provided at the rear end. The tag 42b has a hemispherical shape with a smooth rear end, and has a slightly larger diameter than the column 42a. A part of the tag 42 b is inserted into the hub passage 28.

  The needle 40 is a hollow needle or a solid needle, and is made of a metal such as stainless steel, aluminum or titanium, or a hard resin such as polyphenylene sulfide.

  The needle 40 is for puncturing the skin and is provided in front of the needle body 14. The needle 40 has an outer diameter of about 0.4 mm, and is designed to have a strength that can withstand the impact of puncture and an invasion to human tissue. In the initial state (the state shown in FIG. 4), the tip of the needle 40 is inserted into the needle passage 30.

  The protective cap 15 is a thin cylinder that is inserted into the needle passage 30 and covers the needle 40. The protective cap 15 protrudes moderately from the case 12. The rear end of the protective cap 15 has a tapered shape, and is fixed to the front surface of the hub 42 by means such as fusion or adhesion. The needle 40 is inserted into the protective cap 15 by insert molding. Sealed. The hub 42 and the protective cap 15 may be integrally molded. The protective cap 15 is irradiated with γ rays, electron beams, etc., and the needle 40 in the protective cap 15 is sterilized.

  A coil spring 46 is provided between the tag 42 b and the cylindrical body 24 in the needle body 14. The front end of the coil spring 46 is fixed to the cylinder 24, and the rear end is fixed to the tag 42b. The fixing means is, for example, engagement or adhesion. If a drop prevention mechanism such as locking is provided so that the tag 42b does not fall off the hub passage 28 in the initial state, the front end and the rear end of the coil spring 46 do not necessarily have to be fixed to the cylindrical body 24 and the tag 42b. .

  As apparent from FIG. 4, the needle 40 of the needle body 14 is disposed in the needle passage 30 in the initial state, and the rear end portion of the tag 42 b is disposed substantially below the square hole 26.

  A first cam surface 50 that is inclined is provided on the surface on the side of the lumen 22 below a portion constituting the rear side of the square hole 26 in the rear portion 16. The first cam surface 50 is inclined so as to gradually approach the axis C of the needle body 14 from the square hole 26 toward the rear. The inclination angle θ1 of the first cam surface 50 with respect to the axis C is preferably 30 ° to 45 °, for example, and the puncture apparatus 10 sets θ1 = 40 °. The first cam surface 50 is provided from the upper surface of the case 12 to approximately half the position from the axis C to the lower surface, and a step 50a parallel to the axis C is formed on the lower surface.

  The push rod 17 includes a second cam surface 52, an elastic arm 54, a recess 56, and a pair of left and right guide protrusions 58. The push rod 17 has a shape based on a quadrangular prism. A recess 60 is provided on the rear surface, and an elastic arm 54 is connected to the lower end of the recess 60. The push rod 17 is provided so as to be movable at right angles with respect to the direction of the axis C by projecting almost all of the push rod 17 except the second cam surface 52 from the case 12 in the initial state and the guide protrusion 58 being guided by the guide groove 26a. ing. The moving direction of the push rod 17 is defined as the V direction. Even if the moving direction of the push rod 17 is not perpendicular to the direction of the axis C, it may be in a direction that is not parallel to the direction of the axis C and intersects.

  The second cam surface 52 is an inclined surface provided at the lower end of the push rod 17. When the push rod 17 is pushed down, the second cam surface 52 is brought into sliding contact with the rear end portion of the tag 42 b, thereby causing the needle body 14 to move in the axial direction. Extrude. The second cam surface 52 is disposed above the rear end portion of the tag 42b, and is inclined so as to gradually move away from the axis C of the needle body 14 toward the front. The inclination angle θ2 of the second cam surface 52 with respect to the axis C is preferably 40 ° to 50 °, for example, and the puncture apparatus 10 sets θ2 = 45 °. The second cam surface 52 protrudes further forward than the other part of the push rod 17, and a step 52 a parallel to the axis C is formed on the upper surface.

  When the push rod 17 is pushed down, the elastic arm 54 is slidably contacted with the upper end portion (a part of the case) 50b of the first cam surface 50 and the elastic biasing force is accumulated, and the arm end portion 54a passes through the upper end portion 50b. Then, the first cam surface 50 is pressed while slidingly contacting the first cam surface 50, and the push rod 17 is elastically biased so as to move further downward.

  The elastic arm 54 is connected to the lower end of the recess 60 of the push rod 17, and forms a base end portion 54b that is inclined substantially upward in a substantially straight line, and a gentle arc in a side view continuous to the base end portion 54b. And a free end 54c. The elastic arm 54 is a thin plate, has an appropriate elasticity, and functions as a leaf spring.

  The free end portion 54c has a gentler slope than the base end portion 54b with respect to the V direction, and is directed substantially upward in the initial state. That is, the direction of the arc shape of the free end portion 54 c is a direction approaching the recess 60 of the push rod 17. In the initial state, the inclination angle θ3 of the portion contacting the upper end 50b on the rear surface of the elastic arm 54 with respect to the V direction is preferably, for example, 25 ° to 45 °, and in the puncture device 10, θ3 = 30 °. It is set.

  The recess 56 is provided on the front surface of the push rod 17 slightly above the second cam surface 52. The concave portion 56 has an arc cross-sectional shape in a side view in which the tag 42b can be engaged. After the push rod 17 is pushed down and the second cam surface 52 passes through the axis C, the concave portion 56 is engaged by the tag 42b being elastically biased rearward by the coil spring 46. The concave portion 56 may have, for example, a hemispherical shape that matches the tag 42b.

  As shown in FIG. 4, in the initial state, at least the free end portion 54c of the elastic arm 54 protrudes from the square hole 26, and the base end portion 54b abuts on the rear end side (that is, the upper end portion 50b) of the square hole 26. The push rod 17 is elastically biased in the protruding direction of the needle tip. Thereby, it is possible to prevent the push rod 17 from falling into the case 12 in the initial state. The amount of elastic deformation of the elastic arm 54 in the initial state (that is, the storage state before use) is very small, the elastic strain is very small, and the elastic force does not deteriorate even if stored for a long period of time.

  Note that the force by which the elastic arm 54 pushes the push rod 17 in the protruding direction of the needle tip is greatly influenced by the inclination angle θ3 together with the elastic force of the elastic arm 54.

  That is, as shown in FIG. 6, since the elastic force F generated by the elastic arm 54 is generated perpendicular to the surface of the elastic arm 54, the force Fv that pushes the push rod 17 upward is perpendicular to the elastic force F. The component is F · sin (θ3), and the force Fv increases as the tilt angle θ3 increases. The horizontal component Fc (= F · cos (θ3)) of the elastic force F is a force that pushes the push rod 17 forward, and since the push rod 17 is inserted into the square hole 26, it moves forward. Note that when θ3 = 0, Fv = 0.

  Since the push rod 17 is urged in the protruding direction by the elastic force of the elastic arm 54, the step 52 a at the upper end of the second cam surface 52 abuts on the upper surface of the inner cavity 22 of the case 12. Thereby, it is possible to prevent the push rod 17 from coming out of the case 12.

  The push rod 17 protrudes from the square hole 26 when the push rod 17 is in the initial position, so that it can be easily recognized that the puncture apparatus 10 is not in use and the operability is good. The protruding amount of the push rod 17 from the case 12 in the initial state is preferably 5 mm or more and 30 mm or less so that it can be easily pushed by a hand.

  Next, the operation of the puncture apparatus 10 configured as described above will be described.

  First, by twisting the protective cap 15, the connection portion with the hub 42 is threaded and the protective cap 15 is removed.

  Next, as shown in FIG. 7, the case 12 is held, the distal end surface 12 a is brought into contact with the skin 70, and the push rod 17 is pushed into the inner cavity 22. At this time, for example, the end of the push rod 17 may be pushed with the index finger while holding the lower surface of the case 12 with the thumb and the middle finger. The case 12 is provided with a protrusion 12b that abuts a thumb or the like and is difficult to slip.

  As is clear from FIG. 7, the direction in which the push rod 17 is pushed (the right direction in FIG. 7) is orthogonal to the direction in which the case 12 is pushed (the lower direction in FIG. 7). There is almost no influence on the pressing to 70, and stable pressing is possible.

  Initially, the push rod 17 is pushed down according to the pushing amount of the finger. As the elastic arm 54 is pulled into the square hole 26, the base end portion 54 b is elastically bent while being in sliding contact with the upper end portion 50 b, and approaches the surface of the recess 60.

  As shown in FIG. 8, when the push rod 17 is further pushed, the elastic arm 54 is further elastically bent and reaches a maximum displacement state. Since the elastic arm 54 includes a base end portion 54b and a gentle arc-shaped free end portion 54c, in the maximum displacement state, the elastic arm 54 is entirely forward of the rear end side of the square hole 26 (that is, the upper end portion 50b). Is located. In this maximum displacement state, the arm end portion 54 a does not contact the recess 60, and a slight gap is secured. The second cam surface 52 at the lower end of the push rod 17 comes into contact with the tag 42b when it is in the maximum displacement state or in a minute time before and after that. That is, from this point, the needle body 14 is pushed forward while compressing the coil spring 46 by the sliding contact of the tag 42b with the second cam surface 52.

  By pushing the push rod 17, the elastic deformation amount of the elastic arm 54 increases, but the inclination angle θ 3 decreases. Therefore, the force Fv (see FIG. 6) for pushing the push rod 17 upward gradually decreases, and in the maximum displacement state Since θ3 = 0, Fv = 0 (= F · sin (0)). That is, in the maximum displacement state, there is no force to push the push rod 17 upward, and the push rod 17 can be pushed down with a light force.

  As shown in FIG. 9, when the push rod 17 is further pushed down, the inclination angle θ3 becomes θ3 <0. As a result, the force Fv for pushing the push rod 17 upward is also Fv = F · sin (θ3) <0, and the polarity is reversed and the force is switched to the force for pushing the push rod 17 down. Therefore, thereafter, the push rod 17 is automatically inserted into the lumen 22 without being manually pushed. Moreover, since the absolute value of the inclination angle θ3 gradually increases, the force Fv increases in an acceleration manner (the absolute value increases with a negative value), and the push rod 17 moves vigorously downward.

  That is, since the elastic arm 54 has the arc-shaped free end portion 54c, the elastic arm 54 can automatically shift to a pushing operation from a position where the push rod 17 is pushed in appropriately. Even if the free end 54c is not a circular arc shape but a linear shape, the arm end portion 54a shifts to an automatic operation if it passes through the upper end portion 50b. However, since the free end portion 54c has an arc shape, It is possible to shift to an automatic operation before the end portion 54a passes through the upper end portion 50b.

  In addition, if the elastic arm 54 has a short configuration of only the base end portion 54b (a state where there is no arc-shaped free end portion 54c), it can shift to an automatic operation earlier by a short length, If the elastic arm 54 is short because the elastic compression is insufficient and a strong elastic force is not obtained, a sufficient moving distance cannot be obtained when the first cam surface 50 is slidably contacted.

  On the other hand, the puncture device 10 has not only the substantially straight base end portion 54b but also the arc-shaped tip end portion 54c, so that the elastic arm 54 becomes appropriately long and the push rod 17 can be moved sufficiently. it can.

  As shown in FIG. 10, the elastic arm 54 moves downward together with the push rod 17, and when the arm end portion 54 a passes the upper end portion 50 b of the first cam surface 50, the first cam is slidably contacted with the first cam surface 50. By pressing the surface 50 and returning elastic deformation, the needle body 14 can be further urged by the elastic repulsive force and pushed forward at a high speed. When the arm end portion 54a passes through the upper end portion 50b, the elastic arm 54 is sufficiently elastically deformed, and the needle body 14 can be pushed forward fairly strongly.

  As the needle body 14 advances, the distal end of the needle 40 protrudes from the distal end surface 12a and is punctured into the skin. At this time, the speed of the needle body 14 is substantially accelerated based on the elastic force of the elastic arm 54 regardless of the force and speed of pushing the push rod 17 with a finger, and the needle 40 pierces the skin quickly. The needle body 14 moves forward to reach the maximum puncture depth until the tag 42b reaches the upper end of the second cam surface 52.

  As shown in FIG. 11, the second cam surface 52 exceeds the axis C, and the tag 42 b comes off from the second cam surface 52, and there is no force to push the needle body 14 forward. Thereafter, the compressed coil spring 46 extends to push the needle body 14 backward, the needle 40 quickly comes out of the skin, and the needle 40 is stored in the needle passage 30. Thus, the needle body 14 after puncturing is automatically and quickly pulled out, and pain is further reduced.

  The push rod 17 moves downward and eventually reaches the movement end position, the tag 42b moves rearward through the second cam surface 52 and engages with the recess 56, and the arm end 54a of the elastic arm 54 is It stops by passing through one cam surface 50 and entering below the step 50a. The engagement between the tag 42b and the recess 56 and the engagement between the elastic arm 54 and the step 50a cause the needle body 14 and the push rod 17 to engage with each other and be fixed in the puncture device 10, so that the puncture device 10 is reconnected. Never used. At the movement end position, the elastic arm 54 extends, and the inclination angle θ3 is equal to or greater than 30 ° (see FIG. 4) in the initial state.

  The push rod 17 is almost (or completely) inserted into the lumen 22, and thereafter the push rod 17 is not inadvertently operated. The protruding amount of the push rod 17 after the puncturing operation is made to be less than 5 mm. Thereby, it can be easily recognized whether the puncture apparatus 10 is before use or has been used.

  The series of puncturing operations shown in FIGS. 4, 8, 10, and 11 are performed in a very short time, and the tip of the needle 40 protrudes from the tip opening 30a for a moment.

  In this way, the puncture is easily performed, and an appropriate amount of blood comes out from the skin. Therefore, blood components are measured with a predetermined blood glucose meter or the like. The puncture device 10 after use is discarded. When discarding, the needle 40 is completely inserted into the needle passage 30 so that it cannot be touched carelessly.

  As described above, in the puncture device 10 according to the present embodiment, the elastic arm 54 is once elastically deformed by pushing down the push rod 17, and then returns from the deformed state along the first cam surface 50. The needle body 14 can be pushed out automatically and vigorously by the elastic force of the elastic arm 54. Thus, reliable puncture is possible, and the operation is fast and pain is reduced.

  The puncture device 10 has a simple structure and can be mass-produced at a low cost, and thus is suitable as a so-called disposable product for single use. The puncture device 10 is basically composed of a composite body including the needle body 14 and the protective cap 15, a push rod 17, a coil spring 46, and a case 12, and has a small number of parts and is simple. And easy to assemble.

  In the puncture device 10, the operation of the needle body 14 is performed automatically and at high speed based on the elastic force of the elastic arm 54 without being substantially affected by human finger operation. Therefore, the speed of puncture is fast and it is difficult to feel pain. After the needle tip comes into contact with the skin, the needle body 14 automatically punctures the skin even if the patient does not actively push the push rod 17, so that the patient's mental resistance is low and the patient accepts it. Cheap.

  As shown in FIG. 12, the front end surface 12 a in the front portion 18 may be constituted by a nut body 100 and screwed to the front portion 18. According to the nut body 100, the protruding amount of the needle 40 can be adjusted by the degree of screwing. The nut body 100 may be provided with an index mechanism that can set the degree of screwing in several stages. Of course, the mechanism for adjusting the protruding amount of the needle 40 may be a mechanism other than this.

  The puncture device according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

It is a perspective view of the puncture device concerning this embodiment. It is a disassembled perspective view of the puncture apparatus which concerns on this embodiment. It is a partial cross section perspective view of the puncture device concerning this embodiment. It is a cross-sectional side view of the puncture device in an initial state. It is a perspective view of the case which concerns on the modification of the state which expand | deployed. FIG. 6 is a dynamic schematic diagram showing an elastic arm and an upper end portion of a first cam surface in an initial state in which a push rod is pushed down. It is a schematic diagram of the state which contact | abutted the puncture apparatus to skin. It is a cross-sectional side view of the puncture device in the maximum displacement state of the elastic arm. It is a dynamic schematic diagram showing the elastic arm and the upper end of the first cam surface in a state where the elastic arm exceeds the maximum displacement. It is a cross-sectional side view of the puncture device in the maximum displacement state of the needle body. It is a cross-sectional side view of a puncture device when a push rod will be in a movement completion state. It is an expanded sectional top view of the front-end | tip part in which the nut body which adjusts the protrusion amount of a needle | hook is provided.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Puncture device 12 ... Case 14 ... Needle body 15 ... Protection cap 17 ... Push rod 24 ... Cylindrical body 26 ... Square hole 40 ... Needle 42 ... Hub 42a ... Column body 42b ... Tag 46 ... Coil spring 50 ... First cam surface 50a, 52a ... step 50b ... upper end 52 ... second cam surface 54 ... elastic arm 54a ... arm end 54b ... base end 54c ... free end (tip)
56 ... Recess C ... Shaft

Claims (5)

A needle body comprising a needle and a hub for holding the needle;
A case having a tip opening that guides the needle body in the axial direction and the tip of the needle protrudes instantaneously;
A push rod provided in an initial state with a part protruding from the case and capable of moving non-parallel to the axial direction of the needle body;
A first cam surface provided in the case;
Have
The push rod is slidably brought into contact with the end of the needle body by being pushed down, and pushes the needle body in the axial direction;
Elastically deformed by sliding contact with a part of the case, and after passing through a part of the case, presses the first cam surface while slidingly contacting the first cam surface, so that the push rod moves further. An elastic arm for biasing;
A puncture device comprising: The puncture device according to claim 1, wherein
The push rod has a recess with which the end of the needle body engages after the second cam surface passes through the central axis of the needle body,
An elastic body is provided between the needle body and the case, and the elastic body presses the needle body in the direction of the recess after the second cam surface passes through the central axis. Puncture device to do. The puncture device according to claim 1 or 2,
The push rod is provided in a hole that opens on a side surface of the case,
In the initial state, the elastic arm projects at least partially from the hole, contacts the hole of the case, and elastically biases the push rod in the protruding direction of the needle body. The puncture device according to any one of claims 1 to 3,
The puncture device according to claim 1, wherein a step at one end of the second cam surface abuts against a lumen surface of the case in an initial state. The puncture device according to any one of claims 1 to 4,
The puncture apparatus according to claim 1, wherein the elastic arm has an arcuate portion in a free end portion in a direction approaching the push rod.

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