JP5372791B2 - Insertion needle and catheter set - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insertion needle and a catheter set, capable of making the distal end of a catheter reach a medication target part while evading the important tissue of a blood vessel, a pancreatic duct and a lymph vessel, etc. <P>SOLUTION: The insertion needles 3, 4 housed in the lumen of the catheter so as to be freely inserted and pulled out include: puncture units 32, 42 provided with sharp distal ends 31, 41 and provided with side faces to be slidably fitted with the inner surface of the lumen 21 of the catheter 2; projecting members 35, 45 provided on the side faces of the puncture units 32, 42; and linear members 33, 43 extended from the puncture units 32, 42 to the proximal end side and having a diameter smaller than the diameter of the lumen. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an insertion needle and a catheter set that are housed in a catheter that is punctured into a living tissue of a mammal including a human.

  Conventionally, for the purpose of medication, a tubular catheter has been inserted into the living tissue of mammals including humans, and fluids such as drugs have been discharged from the through holes at the distal end of the catheter. As such a catheter, an indwelling catheter comprising a tube-shaped catheter body and a bent elastic wire inserted at one end inside the catheter, and mainly administering a drug solution such as an anticancer drug into the blood vessel in the vicinity of the tumor Has been proposed (see, for example, Patent Document 1). By using this catheter to administer an anticancer agent to blood vessels in the vicinity of the tumor, damage to normal cells is reduced, and an anticancer effect is achieved with a small amount of drug.

Japanese Patent No. 3274384

  However, in the method described in Patent Document 1, a drug is injected into the blood vessel, and the drug cannot contact the tumor cells until the drug in the blood leaks out of the blood vessel. There was a problem that many were not taken up by the tumor, but circulated in the body through the bloodstream and excreted.

  For this reason, in recent years, in order to increase the amount of the drug in contact with tumor cells and further improve the drug efficacy, it is required to inject the drug directly into the tissue in the vicinity of the tumor. According to this method of directly injecting a drug into a tissue, the dose of the drug can be reduced as compared with the method of injecting the drug into the blood vessel, so that a reduction in side effects can be expected.

  Here, in the method of directly injecting the drug into the tissue, when the catheter is punctured into the living tissue, avoid the important tissue such as blood vessels, pancreatic ducts, lymphatic vessels, etc. in the tissue and the body surface as much as possible, and the tip of the catheter is affected. There is a strong demand to reach the medication purpose part.

  The present invention has been made in view of the above, and provides an insertion needle and a catheter set that can allow the distal end of a catheter to reach the administration target portion while avoiding important tissues such as blood vessels, pancreatic ducts, and lymphatic vessels. With the goal.

  In order to solve the above-described problems and achieve the object, an insertion needle according to the present invention is introduced into a living tissue of a mammal including a human, and can be inserted into and removed from a lumen of a tubular catheter whose tip is open. A puncture unit having a pointed tip and a side surface slidably fitted to the inner surface of the lumen of the catheter; and provided on a side surface of the puncture unit, the puncture unit A projecting member having a projecting portion projecting outward from a side surface of the piercing unit, and a linear member extending from the puncture unit to the proximal end side and having a diameter smaller than the diameter of the lumen, the projecting member comprising: When the insertion needle is inserted into the lumen of the catheter, the protruding portion abuts against a predetermined portion of the catheter tip, thereby opening the catheter tip. The puncture unit is positioned at a position where the distal end of the puncture unit protrudes, and the linear member extends from the proximal end of the catheter in a state where the distal end of the puncture unit protrudes from the opening of the catheter distal end. The base member has a length protruding from the base end.

  The insertion needle according to the present invention is characterized in that, in the above invention, the protruding member is biased so as to protrude in a radial direction of the puncture unit from a side surface of the puncture unit.

  The insertion needle according to the present invention is characterized in that, in the above invention, the protruding member is a stopper member biased by an elastic member.

  In the insertion needle according to the present invention as set forth in the invention described above, the projecting member is a spring that can project in the radial direction of the puncture unit.

  In the insertion needle according to the present invention, in the above invention, the protruding member is a rubber ring member protruding in the radial direction of the puncture unit, or a ring-shaped balloon that expands in the radial direction of the puncture unit. It is characterized by being.

  Further, the catheter set according to the present invention has a plurality of insertion needles each having a different degree of sharpness of the tip and a lumen capable of accommodating one insertion needle selected from the plurality of insertion needles, and the tip is opened. A tubular catheter, and each insertion needle has a pointed tip and a puncture unit having a side surface slidably fitted to the inner surface of the lumen of the catheter, and projects outward from the side surface of the puncture unit A projecting member provided on the side surface, and a linear member extending from the puncture unit toward the proximal end and having a diameter smaller than the diameter of the lumen. When the insertion needle is inserted into the lumen of the catheter, the member contacts the predetermined portion of the catheter tip, so that the protruding portion of the catheter tip The puncture unit is positioned at a position where the distal end of the puncture unit protrudes from the mouth, and the linear member extends from the proximal end of the catheter with the distal end of the puncture unit protruding from the opening of the catheter distal end. It has the length which the base end part of the said linear member protrudes.

  The catheter set according to the present invention is characterized in that, in the above-mentioned invention, a tapered surface on which the protruding portion is slidable is formed at the distal end of the catheter.

  In the catheter set according to the present invention as set forth in the invention described above, the tapered surface is provided over the entire circumference of the lumen opening at the distal end of the catheter.

  The catheter set according to the present invention is characterized in that, in the above invention, the tapered surface is provided only in a part of the circumference of the lumen opening at the distal end of the catheter.

  According to the present invention, a puncture unit that is an insertion needle that can be inserted into and withdrawn from a lumen of a catheter, has a pointed tip, and has a side surface that slidably fits with the inner surface of the lumen of the catheter. Each insertion needle provided with a protruding member provided on the side surface of the puncture unit and a linear member having a diameter smaller than the diameter of the lumen extending from the puncture unit to the proximal end side is replaced according to the puncture target Thus, it is possible to smoothly reach the tip of the catheter to the administration target portion while avoiding important tissues such as blood vessels, pancreatic ducts and lymphatic vessels.

FIG. 1 is a perspective view illustrating an example of a catheter set according to an embodiment. FIG. 2 is a diagram illustrating a method of using the catheter set shown in FIG. FIG. 3 is a perspective view of the distal end portion of the insertion needle shown in FIG. 4 is an exploded perspective view of the distal end portion of the insertion needle shown in FIG. FIG. 5 is a cross-sectional view of the catheter and insertion needle shown in FIG. 1 when cut in the axial direction of the catheter. 6 is a cross-sectional view taken along line AA and a cross-sectional view taken along line BB in FIG. FIG. 7 is a perspective view of the distal end portion of the insertion needle shown in FIG. FIG. 8 is an exploded perspective view of the distal end portion of the insertion needle shown in FIG. FIG. 9 is a perspective view showing another example of the catheter shown in FIG. FIG. 10 is a cross-sectional view when the opening at the distal end of the catheter is cut along a plane perpendicular to the axial direction with the insertion needle inserted into the catheter shown in FIG. 11 is an exploded perspective view showing another example of the distal end portion of the insertion needle shown in FIG. 12 is an exploded perspective view showing another example of the distal end portion of the insertion needle shown in FIG. FIG. 13 is an exploded perspective view showing another example of the distal end portion of the insertion needle shown in FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. An insertion needle that is punctured into a living tissue of a mammal including a human and administers a drug and a catheter set including the insertion needle will be described. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals.

(Embodiment)
FIG. 1 is a perspective view showing an example of a catheter set according to the present embodiment. As shown in FIG. 1, a catheter set 1 according to the present embodiment is punctured into a living tissue of a mammal including a human. The catheter set 1 includes a tubular elongated catheter 2 having a lumen 21 therein, and a plurality of insertion needles 3 and 4 having different tip sharpness.

  The catheter 2 is provided with an opening 23 communicating with the lumen 21 at the distal end. An opening 22 is also provided at the proximal end of the catheter 2, and a drug or the like can be input from the opening 22. The catheter 2 is made of a biocompatible flexible material (for example, polyurethane, elastic silicon, fluororesin, polyvinyl chloride, polyethylene, natural rubber).

  The insertion needles 3 and 4 are accommodated in the lumen 21 of the catheter 2 so as to be freely inserted and extracted. The insertion needle 3 has a puncture unit 32 having a needle-like tip 31 and a linear member 33 extending from the puncture unit 32 to the proximal end side. The linear member 33 has a diameter smaller than the diameter of the lumen 21 of the catheter 2 and is formed of, for example, a wire. Similarly to the insertion needle 3, the insertion needle 4 also has a puncture unit 42 having a needle-like tip 41 and a linear member 43 extending from the puncture unit 42 to the proximal end side. The linear member 43 has a diameter smaller than the diameter of the lumen 21 of the catheter 2 and is formed of, for example, a wire. The linear members 33 and 43 are arranged so that the bases of the linear members 33 and 43 are formed from the opening 6 at the proximal end of the catheter 2 even when the distal ends 31 and 41 of the puncture units 32 and 42 protrude from the opening 23 at the distal end of the catheter 2. The end has a protruding length.

  The insertion needle 3 and the insertion needle 4 are different in the sharpness of the tips 31 and 41, and FIG. 1 shows a case where the tip 31 of the insertion needle 3 is sharper than the tip 41 of the insertion needle 4. The insertion needles 3 and 4 are pushed by the linear members 33 and 43 into the catheter 2 until the distal ends 31 and 41 inserted from the opening 22 into the lumen 21 of the catheter 2 protrude from the opening 23 at the distal end of the catheter 2. By being inserted, it is attached to the catheter 2. The insertion needles 3 and 4 inserted into the catheter 2 are pulled out from the catheter 2 when the linear members 33 and 43 are pulled out from the catheter 2.

  In this catheter set 1, the tip of the catheter 2 is smoothly punctured by replacing the insertion needle inserted into the catheter 2 with one of the insertion needles 3 and 4 that has an appropriate degree of sharpness according to the puncture target. . A method of using the catheter set 1 shown in FIG. 1 will be described. FIG. 2 is a diagram for explaining a method of using the catheter set 1 shown in FIG.

  First, when the skin on the organ surface is punctured, the insertion needle 3 having a relatively high tip sharpness is selected from the insertion needles 3 and 4. This is because the surface of the organ has a film, and a certain amount of force is required to puncture the film. For this reason, the insertion needle 3 having a high degree of tip sharpness is more suitable than the insertion needle 4 having a low degree of tip sharpness in the case of puncturing the skin of the organ surface. Therefore, when puncturing the coating on the organ surface, as shown in FIG. 2 (1), the insertion needle 3 is selected and the insertion needle 3 is inserted into the lumen 21 of the catheter 2 as indicated by the arrow Y1. . Then, with the distal end 31 of the insertion needle 3 protruding from the opening 23 at the distal end of the catheter 2, the catheter 2 is punctured to the surface of the organ 8 as indicated by an arrow Y2 in FIG.

  When the distal end of the catheter 2 is punctured to an affected part, for example, a tumor 8a, which is a drug administration target part inside the organ 8, the insertion needle 4 having a relatively low tip sharpness is selected from the insertion needles 3 and 4. . Since the inside of the organ 8 and the tumor are softer than the coating on the organ surface, the sharpness of the needle tip is not necessary as compared with the case of puncturing the coating on the organ surface. In addition, since there are many blood vessels such as blood vessels that perform important functions in the organ, there is a puncture needle whose tip is not so sharp from the viewpoint of protecting these vessels after puncturing the coating on the organ surface. desirable. A blood vessel such as a blood vessel is a tissue mainly containing smooth muscles, elastic fibers and collagen fibers, and has a relatively strong tissue having elasticity. On the other hand, other than the organ vasculature, it is soft parenchyma. For this reason, even when the puncture needle is actually in contact with the vessel, the tip of the needle does not puncture the vessel when the tip is not so sharp, and the vessel avoids the puncture needle. The puncture needle can be deformed to avoid the vessel. Therefore, for the puncture after the puncture of the organ 8 once, the insertion needle 4 having a lower sharpness than the insertion needle 3 used for the puncture of the organ 8 is desirable.

  In order to replace the insertion needle 3 in the catheter 2 with the insertion needle 4, the insertion needle inserted into the catheter 2 as shown by an arrow Y3 in FIG. Pull 3 out. 2 (4), the insertion needle 4 is inserted into the lumen 21 of the catheter 2, and the distal end 41 of the insertion needle 4 is protruded from the opening 23 at the distal end of the catheter 2. With the distal end 41 of the insertion needle 4 protruding from the distal end of the catheter 2, the catheter 2 is punctured to the inside of the tumor 8a inside the organ 8 as indicated by an arrow Y5 in FIG.

  After puncturing the distal end of the catheter 2 to the inside of the tumor 8a, the insertion member 4 inserted into the catheter 2 is pulled out as indicated by an arrow Y6 in FIG. Then, by introducing a drug or the like from the opening 22 at the proximal end of the catheter 2, the drug is administered into the tumor 8a from the opening 23 at the distal end of the catheter 2 as indicated by an arrow Y7.

  In this way, when puncturing the surface of the organ 8, the insertion needle 3 having a relatively high sharpness is inserted into the lumen 21 of the catheter 2 to puncture the inside of the organ 8 or the tumor 8a. In this case, by inserting the insertion needle 4 having a relatively low tip sharpness into the lumen 21 of the catheter 2 and performing puncturing, the tip of the catheter 2 can be reliably punctured on the surface of the organ 8, and blood vessels, pancreatic ducts, lymph The tip of the catheter 2 can smoothly reach the administration target portion while avoiding an important tissue such as a tube.

  Next, the puncture unit for each insertion needle shown in FIG. 1 will be described. First, the puncture unit 32 of the insertion needle 3 will be described with reference to FIG. FIG. 3 is a perspective view of the distal end portion of the insertion needle 3 shown in FIG. As shown in FIG. 3, the puncture unit 32 at the distal end of the insertion needle 3 has a shape in which a cone having a sharp tip 31 is formed on a cylindrical body. The protruding member 35 is provided. Each protruding member 35 is provided with a protruding portion 35 a that protrudes outward in the radial direction of the side surface 34. The cylindrical body constituting the puncture unit 32 has a shape and a size such that the side surface 34 of the cylindrical body can be slidably fitted to the inner surface of the lumen 21 of the catheter 2. The projecting member 35 is inclined along the axial direction of the puncture unit 32 from the projecting portion 35a which is the apex toward the distal end side of the puncture unit 32, and from the projecting member 35a toward the proximal end side of the puncture unit 32. And an inclined surface inclined. The protruding member 35 functions as a stopper.

  4 is an exploded perspective view of the distal end portion of the insertion needle 3 shown in FIG. As shown in FIG. 4, each projecting member 35 is attached to the shaft member 6 by a spring that is an elastic member 5, and the shaft member 6 and the linear member 33 are coaxially arranged via the base plate 7. It is connected. When assembling the puncture unit 32, each protruding member 35 is attached to the shaft member 6 via each elastic member 5 as indicated by an arrow Y9, and the protruding member 35 is pressed against the shaft member 6 as indicated by an arrow Y8. Cover the outer rim 36 of the puncture unit 32 from the distal end side, and connect the bottom rim of the outer rim 36 to the periphery of the base plate 7. A window 37 is formed in the exterior 36 so that the protruding portion 35 a of the protruding member 35 can protrude.

  Because of this configuration, the protruding portion 35 a of the protruding member 35 is urged by the elastic member 5 so as to protrude from the side surface 34 of the puncture needle unit 32 to the radially outer side of the puncture unit 32. When a force larger than the urging force of the elastic member 5 is applied from the radially outer side to the inner side of the side surface 34, the protruding portion 35 a protruding from the side surface 34 is pushed into the exterior 36.

  FIG. 5 is a cross-sectional view when the catheter 2 and the insertion needle 3 are cut in the axial direction of the catheter 2, FIG. 6 (1) is a cross-sectional view taken along the line AA in FIG. 5, and FIG. FIG. 6 is a sectional view taken along line BB in FIG. 5.

  As shown in FIGS. 5 (1) to 5 (3), a tapered surface 23a is formed on the entire circumference of the opening 23 at the distal end of the catheter 2 so as to incline from the outside toward the inside. The insertion needle 3 is inserted into the lumen 21 of the catheter 2 through the opening 22 at the proximal end of the catheter 2 and pushed in until the distal end 31 projects from the opening 23 at the distal end of the catheter 2. In this case, as shown in FIG. 5 (1), the protruding member 35 has the protruding portion 35a and the proximal inclined surface abut against the tapered surface 23a of the opening 23 at the distal end of the catheter 2. The puncture unit 32 is positioned at a position where the distal end 31 of the puncture unit 32 protrudes from the opening 23 at the distal end of the catheter 2. The protruding portion 35 a of the protruding member 35 is biased by the elastic member 5 so as to protrude radially outward from the side surface 34 of the puncture needle unit 32. The force with which the elastic member 5 urges the protruding portion 35a radially outward is greater than the radially inner force applied to the protruding portion 35a when the catheter 2 with the insertion needle 3 is punctured into the body tissue. Is set to Therefore, the protruding portion 35a is not pushed into the exterior 36 of the puncture unit 32 by the movement of puncturing the catheter 2 into the body tissue, and the protruding portion 35a and the proximal inclined surface are formed on the tapered surface 23a of the opening 23. In order to maintain the contact state, the puncture unit 32 is not displaced from the position where it is positioned.

  Note that the linear member 33 has a length that the proximal end of the linear member 33 projects from the proximal end of the catheter 2 even when the distal end 31 of the puncture unit 32 projects from the opening 23 at the distal end of the catheter 2. Have.

  Next, when the insertion needle 3 is replaced with the insertion needle 4, the operator pulls out the linear member 33 protruding from the proximal end of the catheter 2, and as shown by an arrow Y <b> 11 in FIG. The member 33 is withdrawn from the catheter 2. Thus, by pulling out the linear member 33 protruding from the proximal end of the catheter 2, a force pulled in the direction of the arrow Y11 is also applied to the puncture unit 32 connected to the distal end of the linear member 33. As a result, FIG. 5 (1) and an arrow Y12 in FIG. 6 (1), a force is applied to push the protruding portion 35a of the protruding member 35 into the exterior 36 from the tapered surface 23a. When the linear member 33 is pulled out so that the pushing force indicated by the arrow Y12 is larger than the urging force of the elastic member 5, as shown by the arrow Y13 in FIG. The projecting member 35 is pushed into the exterior 36 while the end-side inclined surface slides on the taper surface 23a toward the base end side (see FIG. 6B). As a result, the projecting member 35 is released from the state in contact with the tapered surface 23 a of the opening 23, so that the positioned puncture unit 32 can also move within the lumen 21 of the catheter 2. According to the drawing operation of the linear member 33, the protruding tip 31 of the puncture unit 32 is drawn into the lumen 21 of the catheter 2, and the puncture unit 32 further passes through the lumen 21 of the catheter 2 as indicated by an arrow Y14. It moves toward the proximal end of the catheter 2. By this movement, the puncture needle 3 is extracted from the catheter 2 (see FIG. 5 (3)).

  Then, the insertion needle 4 is inserted into the lumen 21 of the catheter 2 from the opening 22 at the proximal end of the catheter 2 and pushed into the lumen 2 of the catheter 2 until the distal end 41 protrudes, thereby inserting the catheter 2 into the catheter 2. The needle is replaced with the insertion needle 4.

  As shown in FIG. 7 (1) which is a perspective view of the insertion needle 4 and FIG. 7 (2) which is an exploded perspective view of the distal end portion of the insertion needle 4, the puncture unit 42 of the insertion needle 4 is Except for the tip 41 having a lower degree of sharpness than the tip 31, a cone is formed on the cylindrical body like the puncture unit 32 in the insertion needle 3, and the protruding portions of the plurality of protruding members 45 are formed from the side surface 44 of the cylindrical body. 45 a has a structure protruding toward the outside of the side surface 44. The projecting member 45 is inclined along the axial direction of the puncture unit 42 from the projecting portion 45a that is the apex toward the distal end side of the puncture unit 42, and from the projecting portion 45a toward the proximal end side of the puncture unit 42. And an inclined surface inclined. In the puncture unit 42, as in the puncture unit 32, each protruding member 45 is attached to the shaft member 6 via the elastic member 5 as indicated by an arrow Y 9 a and the protruding member 45 is pressed against the shaft member 6. Then, the exterior 46 of the puncture unit 42 is covered from the distal end side as indicated by the arrow Y8a, and the bottom rim of the exterior 46 is connected to the periphery of the base plate 7. A window 47 is formed in the exterior 46 as in the exterior 36. The shaft member 6 and the linear member 43 are coaxially connected via the base plate 7.

  The insertion needle 4 is inserted into the lumen 21 of the catheter 2 through the opening 22 at the proximal end of the catheter 2, and the distal end 41 projects from the opening 23 at the distal end of the catheter 2 as indicated by an arrow Y15 shown in FIG. Pushed in. In the protruding member 45, the protruding portion 45a and the base-side inclined surface slide along the tapered surface 23a toward the distal end side as indicated by an arrow Y16, and further, an elastic member in the direction of the arrow Y17 in FIG. 5 is pushed outward from the exterior 46 and abuts against the tapered surface 23 a of the opening 23 at the distal end of the catheter 2. As a result, as shown in FIG. 8 (2), the puncture unit 42 is positioned at a position where the tip 41 of the puncture unit 42 protrudes from the opening 23 at the tip of the catheter 2.

  By using the insertion needles 3 and 4 having such a structure, the insertion needle can be easily replaced with the catheter 2 according to the puncture target. Of course, the number of insertion needles is not limited to the two insertion needles 3 and 4, and may be selected in a timely manner corresponding to the puncture target among the insertion needles having different tip sharpness.

  In the present embodiment, the case where the taper is provided over the entire circumference of the opening 23 at the distal end of the catheter 2 has been described, but the present invention is not limited to this. FIG. 9 is a perspective view showing another example of the catheter shown in FIG. 2, and shows the distal end portion of the catheter. As in the catheter 2a of FIG. 9, a tapered surface 23b may be provided on a part of the opening 231a by obliquely notching a part of the surface 23c cut perpendicular to the axial direction. Each tapered surface 23b is formed corresponding to the arrangement of the protruding portions 35a, 45a of the protruding members 35, 45 in the puncture units 32, 42.

  FIG. 10 is a cross-sectional view when the opening 231a at the distal end of the catheter 2a is cut along a plane perpendicular to the axial direction in a state where the insertion needle 3 is inserted into the catheter 2a shown in FIG. A tapered surface 23b is formed in the opening 231a of the catheter 2a so as to correspond to the protruding portion 35a of the protruding member 35. For this reason, after inserting the insertion needle 3 into the lumen 21 of the catheter 2a until the distal end 31 of the puncture unit 32 protrudes from the opening 231a of the catheter 2a, the insertion needle 3 as shown by an arrow Y18 in FIG. Is rotated at least 45 degrees around the axis, the protruding member 35 protruding outward as shown by the arrow Y19 in FIG. The protruding member 35 fitted to the tapered surface 23b is prevented from rotating around the axis by the wall surface 23e of the notch portion shown in FIG. 9, so that the puncture unit 32 also does not rotate around the axis. Therefore, when this catheter 2a is used, rotation around the axis of the puncture unit 32 when the catheter 2a is punctured into the body tissue can be prevented.

  Moreover, in this Embodiment, you may form the protrusion member in each insertion needle 3 and 4 with a leaf | plate spring. In this case, as shown in FIG. 11, a cone having a pointed tip 31 can protrude toward the outer side in the radial direction of the cylindrical body of the exterior 36a on the side surface 34a of the exterior 36a formed on the cylindrical body. A certain leaf spring 35a may be provided. Moreover, in this Embodiment, you may form the protrusion member of each insertion needle 3 and 4 with rubber | gum. In this case, as shown in FIG. 12, a rubber projecting toward the outer side in the radial direction of the cylindrical body of the exterior 36b is formed on the side surface 34b of the exterior 36b in which a cone having a sharp tip 31 is formed on the cylindrical body. What is necessary is just to provide the ring member 35b made from. Moreover, in this Embodiment, you may form the protrusion member of each insertion needle 3 and 4 with a balloon. In this case, as shown in FIG. 13, a ring having a conical body having a pointed tip 31 is expanded on the side surface 34c of the exterior 36c formed on the cylindrical body, and expands radially outward of the cylindrical body of the exterior 36c. A shaped balloon member 35c may be provided.

  The tip portions of the outer sheaths 36, 36a to 36c, 46 of the insertion needles 3 and 4 can be formed using a metal such as stainless steel, titanium, or aluminum, a fluororesin, or other various engineering plastic resins.

DESCRIPTION OF SYMBOLS 1 Catheter set 2, 2a Catheter 3, 4 Insertion needle 5 Elastic member 6 Shaft material 7 Base plate 21 Lumen 22, 23 Opening part 31, 41 Tip 32, 42 Puncture unit 35, 45 Protrusion member 36, 46 Exterior 37, 47 Window

Claims (9)

An insertion needle that is introduced into the living tissue of mammals including humans and is housed so as to be freely inserted into and withdrawn from the lumen of a tubular catheter having an open tip,
A puncture unit having a pointed tip and a side surface slidably fitted to the inner surface of the lumen of the catheter;
A projecting member provided on a side surface of the puncture unit and having a projecting portion projecting outward from the side surface of the puncture unit;
A linear member extending from the puncture unit toward the proximal end and having a diameter smaller than the diameter of the lumen;
With
When the insertion needle is inserted into the lumen of the catheter, the protruding member is configured such that the protruding portion comes into contact with a predetermined portion of the catheter tip, so that the tip of the puncture unit protrudes from the opening of the catheter tip. Positioning the puncture unit at a position to
The linear member has a length such that the proximal end portion of the linear member projects from the proximal end of the catheter in a state where the distal end of the puncture unit projects from the opening of the catheter distal end. Insert needle.   The insertion needle according to claim 1, wherein the protruding member is biased so as to protrude in a radial direction of the puncture unit from a side surface of the puncture unit. The insertion needle according to claim 2, wherein the protruding member is a stopper member biased by an elastic member. The insertion needle according to claim 1, wherein the projecting member is a spring that can project in a radial direction of the puncture unit. 2. The insertion needle according to claim 1, wherein the protruding member is a rubber ring member protruding in a radial direction of the puncture unit or a ring-shaped balloon that expands in a radial direction of the puncture unit. . A plurality of insertion needles each having a different tip sharpness;
A tubular catheter having a lumen capable of accommodating one insertion needle selected from the plurality of insertion needles and having an open end;
With
Each insertion needle
A puncture unit having a pointed tip and a side surface slidably fitted to the inner surface of the lumen of the catheter;
A projecting member provided on a side surface of the puncture unit and having a projecting portion projecting outward from the side surface of the puncture unit;
A linear member extending from the puncture unit toward the proximal end and having a diameter smaller than the diameter of the lumen;
Each with
When the insertion needle is inserted into the lumen of the catheter, the protruding member is configured such that the protruding portion comes into contact with a predetermined portion of the catheter tip, so that the tip of the puncture unit protrudes from the opening of the catheter tip. Positioning the puncture unit at a position to
The linear member has a length such that the proximal end portion of the linear member projects from the proximal end of the catheter in a state where the distal end of the puncture unit projects from the opening of the catheter distal end. Catheter set.   The catheter set according to claim 6, wherein a tapered surface on which the protrusion is slidable is formed at a distal end of the catheter.   The catheter set according to claim 7, wherein the tapered surface is provided over the entire circumference of the lumen opening at the distal end of the catheter.   The catheter set according to claim 7, wherein the tapered surface is provided only in a part of the circumference of the lumen opening at the distal end of the catheter.

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