JP2011120760A - Indwelling needle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an indwelling needle preventing an outer needle from falling out of an inner needle by the operation of fine movement in front and back directions during puncture and also preventing the inner needle from becoming undetachable from the outer needle after the puncture, by setting mutual fixing force of the outer needle and the inner needle to an appropriate range. <P>SOLUTION: The indwelling needle 10 includes the outer needle 12 having an outer needle body 16 and an outer needle hub 18, and the inner needle 14 having an inner needle body 20 and an inner needle hub 22. The outer needle 12 is provided with a fitting inner surface 26 extending in parallel with an axial direction. The inner needle 14 is provided with a fitting outer surface 30 extending in parallel with the axial direction, to be abutted on the fitting inner surface 26 when mounting the inner needle 14 on the outer needle 12. By frictional force between the fitting inner surface 26 and the fitting outer surface 30, the outer needle 12 and the inner needle 14 are mutually fixed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an indwelling needle that is punctured and placed in a blood vessel to perform infusion, blood transfusion, and the like.

  Conventionally, an indwelling needle that is temporarily placed in a blood vessel is frequently used for blood transfusion or infusion (for example, see Patent Document 1 below). For example, when an infusion such as a nutrient is infused into a patient, an indwelling needle having a catheter (outer needle) and a puncture needle (inner needle) is punctured into the patient, and the tip of the indwelling needle is inserted into a blood vessel (vein). Then, the puncture needle is removed, the catheter is left punctured, and the infusion is performed by connecting an infusion line to which a nutrient solution, a drug solution, or the like is supplied.

  Such a technique for puncturing an indwelling needle includes a method of puncturing blindly and an ultrasonic guided puncture method using ultrasonic waves (see, for example, Patent Documents 2 and 3 below). In the ultrasonic guided puncture method, an ultrasonic wave was transmitted from an ultrasonic imaging device, the position of a blood vessel to be punctured was confirmed, the ultrasonic wave was irradiated to the punctured puncture needle, and obtained based on the reflected wave The treatment is performed while confirming the position of the puncture needle based on the image. According to such an ultrasonic guided puncture method, the target blood vessel can be confirmed in real time, and thus there is an advantage that quick puncture is possible.

JP 2004-242762 A Japanese Patent No. 3171525 JP-A-3-228748

  By the way, in recent years, in the ultrasonic guided puncture method, when the indwelling needle advances through the subcutaneous tissue, it is called “jabbing motion” in which the indwelling needle is moved in the front-rear direction (axial direction) like a woodpecker. By performing the operation, the subcutaneous tissue is moved to check the position of the indwelling needle.

  However, in the conventional indwelling needle, the mutual fixation of the outer needle and the inner needle is performed by a crimping portion formed at the tip of the inner needle, and a sufficient fixing force cannot be obtained by fixing with the crimping portion. During the jabbing motion, the outer needle may come off from the inner needle, making it difficult to perform a smooth procedure. On the other hand, it is conceivable that the outer needle and the inner needle are fitted and fixed to each other by the frictional force of the fitting part. However, if the frictional force of the fitting part is excessive, the outer needle is removed from the outer needle after puncturing. A large force is required to remove the inner needle, and as a result, a smooth procedure becomes difficult.

  The present invention has been made in view of the above circumstances, and the mutual fixing force between the outer needle and the inner needle can be set within an appropriate range, whereby the outer needle is moved from the inner needle by an operation of moving in the front-rear direction in small increments. An object of the present invention is to provide an indwelling needle that can prevent the inner needle from coming off from the outer needle after puncturing.

  To achieve the above object, the present invention can be inserted into an outer needle having a tubular outer needle main body, an outer needle hub provided at a proximal end portion of the outer needle main body, and the outer needle main body. An inner needle body and an inner needle having an inner needle hub provided at a proximal end portion of the inner needle body, and the outer needle is provided with a fitting inner surface extending parallel to the axial direction. The inner needle is provided with a fitting outer surface that extends parallel to the axial direction and abuts the fitting inner surface when the inner needle is attached to the outer needle. The outer needle and the inner needle are fixed to each other by a frictional force between the outer and outer surfaces.

  According to the configuration of the present invention, the fitting inner surface of the outer needle and the fitting outer surface of the inner needle are both fitting surfaces parallel to the axial direction, and the outer needle and the inner needle are mutually connected by straight fitting. Since it is fixed, it becomes possible to set the mutual fixing force when the inner needle is attached to the outer needle within a desired appropriate range. As a result, it is possible to prevent the outer needle from coming out of the inner needle by the operation of moving back and forth in small increments during puncturing, and it is possible to prevent the inner needle from coming out of the outer needle after puncturing.

  In the above indwelling needle, the fitting inner surface is provided on the inner surface of the outer needle hub, and the fitting outer surface is provided on the outer surface of the inner needle hub.

  According to said structure, the fitting location of a fitting inner surface and a fitting outer surface is an inside of an outer needle hub, and such a location does not normally enter a body at the time of puncture, ie, it influences puncture. Since the frictional force between the fitting inner surface and the fitting outer surface is not affected by the puncture, the mutual fixing force between the outer needle and the inner needle is kept constant. Accordingly, the outer needle can be reliably prevented from coming out of the inner needle by the operation of moving in the front-rear direction in small increments during puncture.

  In the indwelling needle, a plurality of ribs extending in the axial direction are provided on the outer surface of the inner needle hub at intervals in the circumferential direction, and the fitting outer surface is formed on the outer surface of the rib. It is characterized by that.

  According to said structure, since the frictional force between a fitting inner surface and a fitting outer surface can be easily adjusted by adjusting the width | variety and number of ribs, the mutual fixing force of an outer needle and an inner needle Can be easily set to a desired appropriate range.

  In the indwelling needle, the inner needle hub is provided with a stopper that contacts a predetermined portion of the outer needle hub when the amount of insertion of the inner needle hub into the outer needle hub reaches a predetermined amount. It is characterized by that.

  According to the above configuration, when the amount of insertion of the inner needle hub into the outer needle hub reaches a predetermined amount, the stopper provided on the inner needle hub contacts the predetermined portion of the outer needle hub. Are fitted together with a predetermined amount inserted into the outer needle hub. Therefore, just inserting the inner needle hub into the outer needle hub until the stopper comes into contact with a predetermined part of the outer needle hub, the outer needle hub and the inner needle hub are in a predetermined fitting state. It is possible to prevent a situation where the needle is inserted too much into the outer needle hub or the amount of insertion of the inner needle hub into the outer needle hub becomes too small. As a result, the mutual fixing force between the outer needle and the inner needle can be within a desired range reliably and appropriately.

  The indwelling needle is characterized in that an engaging portion that is hooked to the distal end portion of the outer needle main body is provided in the vicinity of the distal end portion of the inner needle main body.

  According to said structure, when the front-end | tip part of an outer needle main body is hooked by an engaging part, mutual fixation of an outer needle and an inner needle is moderately assisted. Therefore, when sufficient fixing force between the outer needle and the inner needle cannot be obtained only by the frictional force generated by the fitting between the inner surface and the outer surface of the mating, Mutual fixation with the inner needle is reinforced.

  According to the indwelling needle of the present invention, the mutual fixing force between the outer needle and the inner needle can be set within an appropriate range, thereby preventing the outer needle from coming out of the inner needle by an operation of moving back and forth in small increments during puncture. It is possible to prevent the inner needle from being removed from the outer needle after puncturing.

It is a partial cross section whole lineblock diagram showing the indwelling needle concerning a 1st embodiment of the present invention. FIG. 3 is a partially omitted enlarged cross-sectional view showing an outer needle hub, an inner needle hub and a peripheral portion thereof of the indwelling needle according to the first embodiment of the present invention. It is a partial cross section enlarged view which shows the front-end | tip part of the inner needle main body of the indwelling needle which concerns on the 1st Embodiment of this invention, and its vicinity site | part. FIG. 3 is a partially omitted perspective view of the indwelling needle according to the first embodiment of the present invention, showing a state in which the inner needle is inserted into the outer needle halfway. It is sectional drawing by the VV line of FIG. It is a schematic diagram which shows a mode that the indwelling needle which concerns on the 1st Embodiment of this invention is punctured to a patient, and the said indwelling needle is detected with an ultrasonic imaging device. It is a partially-omission perspective view of the indwelling needle which concerns on the 2nd Embodiment of this invention, Comprising: It is a figure which shows the state which inserted the inner needle into the outer needle to the middle. It is a cross-sectional view of the indwelling needle which concerns on the 2nd Embodiment of this invention, Comprising: It is sectional drawing equivalent to the cross section by the VV line in FIG. It is a partial cross section enlarged view which shows the front-end | tip part of the inner needle main body which concerns on a modification, and its periphery site | part.

  Hereinafter, preferred embodiments of an indwelling needle according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a partial cross-sectional overall configuration diagram showing an indwelling needle 10 according to a first embodiment of the present invention. For convenience of explanation, in each attached drawing (excluding some drawings), the axial direction of the indwelling needle 10 and the axial direction of each member constituting the indwelling needle 10 are indicated by an arrow X direction. Moreover, the direction of the indwelling needle 10 and the front-end | tip part side of each member is shown by X1, and the direction of the base end part side of each member is shown by X2.

  As shown in FIG. 1, the indwelling needle 10 includes an outer needle 12 and an inner needle 14 attached to the outer needle 12. The outer needle 12 (catheter) includes a tubular outer needle main body 16 and a hollow cylindrical outer needle hub 18 connected to a proximal end portion of the outer needle main body 16. The inner needle 14 has a tubular inner needle main body 20 and a hollow cylindrical inner needle hub 22 connected to a proximal end portion of the inner needle main body 20. FIG. 1 shows a state in which the inner needle 14 is fitted and attached to the outer needle 12, and in this state, the blade surface 15 formed at the distal end portion of the inner needle main body 20 is the outer needle main body 20. 16 is exposed (protruded) from the tip.

  The outer needle body 16 is made of, for example, a transparent resin material, has an appropriate elasticity, and is formed so as to surround the inner needle body 20. The outer needle body 16 reaches the vicinity of the distal end of the inner needle body 20 when the inner needle 14 is attached to the outer needle 12, and the distal end portion of the inner needle body 20 is inserted into the blood vessel by a predetermined length or more. Then, the distal end portion of the outer needle main body 16 is also inserted into the same blood vessel. Examples of the constituent material of the outer needle body 16 include various soft resins such as ethylene-tetrafluoroethylene copolymer (ETFE), polyurethane, and polyether nylon resin.

  FIG. 2 is a partially omitted enlarged cross-sectional view showing the outer needle hub 18, the inner needle hub 22, and the peripheral portion thereof. As shown in FIG. 2, the outer needle hub 18 is a resin member formed in a hollow cylindrical shape having both ends opened in the axial direction. Examples of the constituent material of the outer needle hub 18 include polyolefin such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer, polyvinyl chloride, polymethyl methacrylate, polycarbonate, polybutyl 32diene, polyamide, and polyester.

  A proximal end portion of the outer needle main body 16 is connected and fixed to a distal end portion of the outer needle hub 18. In the outer needle hub 18, a hub insertion portion 24 having a cylindrical inner surface into which the inner needle hub 22 is inserted is provided on the proximal end side of the connection portion with the outer needle main body 16. The inner diameter of the hub insertion portion 24 increases continuously or stepwise from the distal end side toward the proximal end side (X2 direction). The hub insertion portion 24 has a fitting inner surface 26 that is parallel to the axial direction.

  As shown in FIG. 1, a blade surface 15 that is inclined with respect to the axial direction (X direction) is formed at the distal end portion of the inner needle main body 20. As a constituent material of the inner needle body 20, a material that can sharpen the cutting edge to such an extent that a sufficient puncture force (penetration force) can be obtained and has a strength necessary for puncture is used. For example, stainless steel, aluminum An alloy, a copper alloy, etc. are mentioned.

  The proximal end portion of the inner needle main body 20 is coupled to and held by the distal end portion of the inner needle hub 22. In the vicinity of the distal end portion of the inner needle main body 20 (a predetermined range on the base end side from the blade surface 15), a groove portion 28 that reflects ultrasonic waves is provided over a predetermined range in the axial direction.

  FIG. 3 is an enlarged partial cross-sectional view showing the distal end portion of the inner needle main body 20 and the vicinity thereof. The outer diameter D of the inner needle body 20 is set to 0.7 to 0.8 mm, for example. In the present embodiment, the groove 28 is formed in an annular shape on the outer peripheral surface of the inner needle main body 20, and a plurality of grooves 28 are provided at intervals in the axial direction (X direction) of the inner needle main body 20.

  A distance L1 (see FIG. 1) in the axial direction from the most distal end portion of the inner needle main body 20 to the groove portion 28 closest to the distal end portion is set to, for example, 0.3 to 5 mm. A distance L2 (see FIG. 1) in the axial direction from the most distal end portion of the inner needle main body 20 to the groove portion 28 closest to the proximal end portion is set to 1 to 15 mm, for example.

  In the illustrated inner needle main body 20, the intervals in the axial direction (groove pitch) of the grooves 28 are set to be the same, but some or all of the intervals of the plurality of grooves 28 are set differently. May be. For example, the interval between the groove portions 28 may be reduced toward the distal end side of the inner needle main body 20 (the interval between the groove portions 28 may be increased toward the proximal end portion side of the inner needle main body 20).

  The groove part 28 which concerns on one structural example is circular cross-section, and is formed in the substantially constant depth over the circumferential direction. The width W in the axial direction of the groove portion 28 is set to 5 to 20 μm, for example. The depth H of the groove part 28 in the radial direction is set to 1 to 15 μm, for example.

  As shown in FIG. 2, the inner needle hub 22 is a resin member formed in a hollow cylindrical shape having both ends opened in the axial direction. Examples of the constituent material of the inner needle hub 22 include the same constituent materials as those of the outer needle hub 18 described above.

  The proximal end portion of the inner needle main body 20 is connected and fixed to the distal end portion of the inner needle hub 22. A syringe 40 (see FIG. 6) is detachably connected to the proximal end portion of the inner needle hub 22. A portion of the inner needle hub 22 to be inserted into the hub insertion portion 24 of the outer needle hub 18 extends in parallel with the axial direction, and contacts the fitting inner surface 26 when the inner needle 14 is attached to the outer needle 12. A fitting outer surface 30 is provided in contact therewith. The outer needle 12 and the inner needle 14 are configured such that the inner needle 14 and the outer needle 12 are fixed to each other by a frictional force between the fitting inner surface 26 and the fitting outer surface 30.

  As shown in FIG. 4, in the first embodiment, a plurality of ribs 32 extending in the axial direction are provided on the outer peripheral portion of the inner needle hub 22 at intervals in the circumferential direction. In the illustrated example, three ribs 32 are provided on the outer surface of the inner needle hub 22 at an angular interval of 120 degrees. The aforementioned fitting outer surface 30 is formed on the outer surface of each rib 32. In order for the inner needle 14 and the outer needle 12 to be fixed to each other with a desired fixing force, the outer diameter of the portion provided with the rib 32 of the inner needle hub 22 is the inner diameter of the fitting inner surface 26 of the outer needle hub 18. It is set slightly larger than. The number of ribs 32 may be 2 or 4 or more.

  In each rib 32, a tapered surface 34 whose diameter is increased toward the base end side (X2 direction) is provided at a base end side side of the fitting outer surface 30. The tapered surface 34 is formed as a 6/100 luer taper which is one of international standards. For this reason, the fitting outer surface 30 is provided in the inner needle hub 22 at a position where it does not interfere with the tapered surface 34.

  FIG. 5 is a cross-sectional view taken along the line VV in FIG. As shown in FIG. 5, the fitting outer surface 30 formed on the outer periphery of the rib 32 is formed in an arc shape so as to be in close contact with the fitting inner surface 26 when the inner needle 14 is attached to the outer needle 12.

  As described above, the outer diameter of the portion of the inner needle hub 22 where the ribs 32 are provided is set slightly larger than the inner diameter of the fitting inner surface 26 of the outer needle hub 18, so that as shown in FIG. When the inner needle 14 is attached to the outer needle 12, a fitting inner surface 26 provided on the outer needle hub 18 and a fitting outer surface 30 formed on the outer surface of the rib 32 provided on the inner needle hub 22. The outer needle hub 18 presses the rib 32 radially inward at the contact surface between the fitting inner surface 26 and the fitting outer surface 30. As a result, the outer needle 12 and the inner needle 14 are detachably fitted and fixed to each other with a desired fixing force.

  As shown in FIGS. 2 and 4, the inner needle hub 22 has a stopper 36 that comes into contact with a predetermined portion of the outer needle hub 18 when the insertion amount of the inner needle hub 22 into the outer needle hub 18 reaches a predetermined amount. Is provided. The stopper 36 according to the illustrated configuration example is provided on the inner needle hub 22 on the proximal end side with respect to the fitting outer surface 30, and the insertion amount of the inner needle hub 22 into the outer needle hub 18 becomes a predetermined amount. The outer needle hub 18 is configured to come into contact with the rear end surface (end surface of the base end portion).

  The position where the stopper 36 is provided may be closer to the tip than the illustrated example. In this case, a stopper receiving portion that contacts the stopper 36 when the insertion amount of the inner needle hub 22 into the outer needle hub 18 reaches a predetermined amount may be provided on the inner surface of the hub insertion portion 24 of the outer needle hub 18.

  The indwelling needle 10 according to the first embodiment of the present invention is basically configured as described above, and the operation and effect thereof will be described below.

  In order to attach the inner needle 14 to the outer needle 12, the inner needle 14 is inserted into the outer needle hub 18 and the outer needle 12 from the proximal end side of the outer needle hub 18 as shown in FIG. 4. Then, the fitting outer surface 30 contacts the fitting inner surface 26, and when the amount of insertion of the inner needle hub 22 into the outer needle hub 18 reaches a predetermined amount, the stopper 36 provided on the inner needle hub 22 It abuts on a predetermined portion of the needle hub 18 (in the first embodiment, the end surface of the proximal end portion of the outer needle hub 18). As a result, the inner needle hub 22 is fitted into the outer needle hub 18 with a predetermined amount inserted (see FIGS. 1 and 2).

  Prior to the puncture of the indwelling needle 10, as shown in FIG. 6, a syringe 40 is connected to the proximal end portion of the inner needle hub 22. The syringe 40 includes a cylindrical syringe body 42 and a plunger 44 inserted into the syringe body 42. A connection port 46 is provided at the distal end portion of the syringe body 42, and this connection port 46 is connected to the proximal end portion of the inner needle hub 22. Thus, the syringe 40 communicates with the inside of the inner needle hub 22 via the connection port 46.

  In order to puncture the indwelling needle 10, first, as shown in FIG. 6, a medical staff such as a doctor grasps the indwelling needle 10 and punctures it toward the blood vessel (vein) of the patient 60, and the indwelling needle 10 is desired. Gradually insert toward the site. Thereby, the distal end portion of the indwelling needle 10 advances while opening the body tissue 62.

  On the other hand, simultaneously with puncturing the patient with the indwelling needle 10, the probe 52 of the ultrasonic imaging apparatus 50 is pressed against the vicinity of the puncture site of the patient 60 to irradiate an echo beam (ultrasound) E. The probe 52 is configured to transmit an echo beam E and receive a reflected wave (reflected echo) of the echo beam E.

  The echo beam E is transmitted from the skin surface of the patient 60 toward the inside, and is applied to the distal end portion of the indwelling needle 10. Then, as shown in FIG. 6, the echo beam E is reflected toward the probe 52 by the groove portion 28 formed on the outer peripheral surface in the vicinity of the distal end portion of the inner needle main body 20. The reflected wave of the echo beam E is received by the probe 52.

  As described above, in the present embodiment, the groove portion 28 is formed in a circular arc shape in cross section, and its inner wall surface constitutes an arc-shaped reflection surface. Therefore, even when the puncture angle θ of the indwelling needle 10 is changed, the echo beam E transmitted from the probe 52 by the inner wall surface of the groove portion 28 can be reflected toward the probe 52 side.

  When the reflected wave of the echo beam E is received by the probe 52, the received data is output from the probe 52 to the control unit (not shown) of the ultrasonic imaging apparatus 50 through the lead wire 54 and processed. And displayed as an echo image on the display 56. Specifically, the echo image of the indwelling needle 10 displayed on the display 56 is displayed linearly by the length along the axial direction of the groove 28 detected by the ultrasonic imaging device 50. Accordingly, whether or not the indwelling needle 10 has reached the blood vessel (vein) of the patient 60 can be confirmed based on the echo image displayed on the display 56.

  As described above, in the first embodiment, since the groove portion 28 is formed in an annular shape, the entire circumference serves as a reflection surface, and ultrasonic waves are effectively used regardless of the position around the axis of the inner needle 14 at the time of puncture. Can be reflected. Moreover, since the groove part 28 is provided with two or more in the axial direction of the inner needle main body 20, the part which reflects an ultrasonic wave suitably is provided by that much. As a result, the position of the indwelling needle 10 can be confirmed with higher accuracy by the ultrasonic imaging apparatus 50.

  In the first embodiment, the groove portion 28 is formed in an arc shape in cross section, and the inner wall surface forms an arc-shaped reflection surface, so that the puncture angle θ (see FIG. 6) of the indwelling needle 10 is changed. However, the ultrasonic wave transmitted from the probe 52 by the inner wall surface of the groove portion 28 can be reflected toward the probe 52 side. In other words, regardless of the puncture angle θ of the indwelling needle 10, the ultrasonic wave can be reflected toward the probe 52 and the position of the indwelling needle 10 can be confirmed.

  As described above, the doctor or the like moves the indwelling needle 10 and the probe 52 while confirming the display 56, and guides the distal end portion of the indwelling needle 10 to the blood vessel of the patient 60. At this time, the body tissue 62 is moved by performing an operation (jabing motion) for moving the indwelling needle 10 in the forward and backward direction (axial direction) like a woodpecker, and the position where the indwelling needle 10 is present is confirmed. As described above, the outer needle 12 and the inner needle 14 are fitted to each other at the fitting inner surface 26 and the fitting outer surface 30 and are fixed to each other with an appropriate fixing force by this fitting. Therefore, it is possible to effectively prevent the outer needle 12 from coming out of the inner needle 14 when an operation of moving in the front-rear direction in small increments is performed.

  On the other hand, when the distal end portion of the indwelling needle 10 is guided to the blood vessel of the patient 60, the indwelling needle 10 is advanced while appropriately pulling the plunger 44 of the syringe 40. When the distal end of the indwelling needle 10 is inserted into the blood vessel, blood is introduced into the syringe body 42 through the inside of the inner needle 14 by the internal pressure (blood pressure) of the blood vessel.

  Thus, after confirming that the inner needle body 20 and the outer needle body 16 have been punctured into the blood vessel, the inner needle 14 is removed from the outer needle 12. As described above, the fitting inner surface 26 of the outer needle 12 and the fitting outer surface 30 of the inner needle 14 are both fitting surfaces parallel to the axial direction, and the outer needle 12 and the inner needle 14 are mutually connected by straight fitting. Fixed to. According to the straight fitting, it is possible to set the mutual fixing force when the inner needle 14 is attached to the outer needle 12 within a desired appropriate range. That is, in the case of taper fitting, the fitting force varies greatly depending on the relative positional relationship between the outer needle 12 and the inner needle 14 in the axial direction, so the mutual fixing force between the outer needle 12 and the inner needle 14 is set within an appropriate range. Although it is difficult to do, according to the straight fitting, the mutual fixing force of the outer needle 12 and the inner needle 14 depends on the contact area of the fitting portion and the setting of the inner diameter on the female side and the outer diameter on the male side. Can be easily set to a desired appropriate range. Therefore, by setting the mutual fixing force between the outer needle 12 and the inner needle 14 so that the mutual fixing force between the outer needle 12 and the inner needle 14 does not become excessive, the inner needle 14 cannot be removed from the outer needle 12 after puncturing. Can be prevented.

  After removing the inner needle 14 from the outer needle 12, a guide wire (not shown) is inserted into the blood vessel via the outer needle 12. Next, the outer needle 12 is removed from the patient with the guide wire inserted into the blood vessel. Next, a central venous catheter (not shown) is placed in the blood vessel along the guide wire. Next, an infusion line (not shown) is connected to the central venous catheter to supply nutrients, chemicals, and the like into the blood vessel.

  As described above, according to the indwelling needle 10 according to the first embodiment, the fitting inner surface 26 of the outer needle 12 and the fitting outer surface 30 of the inner needle 14 are both fitting surfaces parallel to the axial direction. Since the outer needle 12 and the inner needle 14 are fixed to each other by the straight fitting, it is possible to set the mutual fixing force when the inner needle 14 is attached to the outer needle 12 within a desired appropriate range. . As a result, it is possible to prevent the outer needle 12 from being removed from the inner needle 14 by an operation of moving in the front-rear direction in small increments, and it is possible to prevent the inner needle 14 from being removed from the outer needle 12 after puncturing.

  Moreover, according to the indwelling needle 10 which concerns on 1st Embodiment, the fitting location of the fitting inner surface 26 and the fitting outer surface 30 is the inside of the outer needle hub 18, and such a location is usually puncture Sometimes it does not enter the body, that is, it does not affect the puncture, and the frictional force between the fitting inner surface 26 and the fitting outer surface 30 is not affected by the puncture, so that the outer needle 12 and the inner needle 14 The mutual fixing force is kept constant. Therefore, it is possible to reliably prevent the outer needle 12 from being removed from the inner needle 14 by an operation of moving back and forth in small increments during puncturing.

  Furthermore, according to the indwelling needle 10 according to the first embodiment, since the fitting outer surface 30 is formed on the outer surface of the plurality of ribs 32 provided on the inner needle hub 22, the width and number of the ribs 32 are adjusted. By doing so, the frictional force between the fitting inner surface 26 and the fitting outer surface 30 can be easily adjusted. Therefore, the mutual fixing force between the outer needle 12 and the inner needle 14 can be easily set within a desired appropriate range.

  Furthermore, when the amount of insertion of the inner needle hub 22 into the outer needle hub 18 reaches a predetermined amount, a stopper 36 provided on the inner needle hub 22 is fixed to a predetermined portion of the outer needle hub 18 (in the first embodiment). The inner needle hub 22 is inserted into the outer needle hub 18 by a predetermined amount, so that they are fitted together. Therefore, only by inserting the inner needle hub 22 into the outer needle hub 18 until the stopper 36 comes into contact with a predetermined portion of the outer needle hub 18, the outer needle hub 18 and the inner needle hub 22 are in a predetermined fitted state. Therefore, the situation where the inner needle hub 22 is inserted too much into the outer needle hub 18 or the amount of insertion of the inner needle hub 22 into the outer needle hub 18 becomes too small is prevented. As a result, the mutual fixing force between the outer needle 12 and the inner needle 14 can be within a desired range reliably and appropriately.

  FIG. 7 is a partially omitted perspective view of the indwelling needle 10a according to the second embodiment. Note that. In the indwelling needle 10a according to the second embodiment, elements having the same or similar functions and effects as those of the indwelling needle 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. .

  As shown in FIG. 7, the indwelling needle 10a according to the second embodiment includes an outer needle 12 and an inner needle 14a. Similar to the first embodiment, the outer needle hub 18 is provided with a fitting inner surface 26 (see FIG. 2) extending parallel to the axial direction. The inner needle hub 22a is provided with a fitting outer surface 30a that extends in parallel with the axial direction and comes into contact with the fitting inner surface 26 when the inner needle 14a is attached to the outer needle 12.

  That is, the fitting outer surface 30 in the first embodiment is formed on the outer surface of the plurality of ribs 32 provided at intervals in the circumferential direction. In the second embodiment, the fitting outer surface 30 corresponds to the ribs 32. The fitting outer surface 30a is not provided, and is configured as a cylindrical surface that goes around the outer periphery of the inner needle hub 22a.

  FIG. 8 is a cross-sectional view corresponding to a cross section taken along line VV in FIG. 2 when the inner needle 14a of the indwelling needle 10a according to the second embodiment is attached to the outer needle 12. As described above, since the fitting outer surface 30a is formed as a cylindrical surface that goes around the outer periphery of the inner needle hub 22a, the fitting outer surface 30a is 360 when the inner needle 14a is attached to the outer needle 12. It contacts and closely contacts the fitting inner surface 26 within a range of degrees.

  Also in the second embodiment configured as described above, the outer needle 12 and the inner needle 14a are fixed to each other by straight fitting, as in the first embodiment. The mutual fixing force of 14a can be set to an appropriate range. Therefore, it is possible to prevent the outer needle 12 from being removed from the inner needle 14a by an operation of moving back and forth in small increments during puncturing, and it is possible to prevent the inner needle 14a from being removed from the outer needle 12 after puncturing.

  In the second embodiment, the same components and the same effects as those provided by the respective components in the first embodiment are the same as or similar to those in the first embodiment. Of course.

  In the first and second embodiments described above, instead of the inner needle body 20, an inner needle body 20a according to a modification shown in FIG. 9 may be applied. An engaging portion 38 on which the distal end portion of the outer needle main body 16 is hooked is provided in the vicinity of the distal end portion of the inner needle main body 20a according to the modified example. In the illustrated example, the engaging portion 38 is configured as a stepped portion 38A. The outer diameter of the stepped portion 38A is such that the stepped portion 38A and the distal end portion of the outer needle main body 16 are disconnected when a predetermined load or more is applied between the stepped portion 38A and the distal end portion of the outer needle main body 16. In addition, it is set slightly larger than the inner diameter of the distal end opening of the outer needle body 16.

  The form of the engaging portion 38 is not limited to the stepped portion 38A, and may be, for example, an annular groove formed on the outer peripheral surface in the vicinity of the distal end portion of the outer needle main body 16, and in this case, the outer needle main body The distal end portion of 16 is formed with a reduced diameter so as to be caught in the annular groove.

  According to said structure, when the front-end | tip part of the outer needle main body 16 is hooked by the engaging part 38, mutual fixation of the outer needle 12 and the inner needle 14 (14a) is moderately assisted. Therefore, when sufficient fixing force between the outer needle 12 and the inner needle 14 (14a) cannot be obtained only by the frictional force generated by the fitting between the fitting inner surface 26 and the fitting outer surface 30 (30a), the engagement is performed. By providing the joint portion 38, mutual fixation between the outer needle 12 and the inner needle 14 (14a) is reinforced.

  Further, by providing the engaging portion 38, the outer needle 12 and the inner needle 14 (14a) can be fixed to each other at the fitting inner surface 26 and the fitting outer surface 30 (30a). It will be done by catching at 38. Therefore, the fixing force by the fitting inner surface 26 and the fitting outer surface 30 (30a) and the fixing force by the engaging portion 38 can be set individually, and the outer needle 12 and the inner needle 14 (14a) can be mutually set. It is possible to easily set the fixing force.

  In the first and second embodiments, the outer needle hub 18 is provided with the fitting inner surface 26, and the inner needle hub 22 (22a) is provided with the fitting outer surface 30, that is, the fitting with the fitting inner surface 26. Although the case where the contact portion with the outer surface 30 (30a) is inside the outer needle hub 18 has been described, a fitting inner surface is provided on the inner peripheral surface of the outer needle body 16, and the fitting outer surface is provided on the outer peripheral surface of the inner needle body 20. It is good also as a structure which provides. In this case, the fitting inner surface provided on the outer needle main body 16 and the fitting outer surface provided on the inner needle main body 20 are configured such that the contact point between them is a position closer to the proximal end portion of the outer needle main body 16. Is preferred. Since such a portion is a portion that does not enter the body during puncture (a portion that does not affect puncture), the friction force between the fitting inner surface and the fitting outer surface is not affected by the puncture. The mutual fixing force of the inner needle 14 (14a) is kept constant.

  In the said 1st and 2nd embodiment, although the case where it uses as a needle | hook (guide wire introduction needle) for introduce | transducing a guide wire in a blood vessel was demonstrated as an example of use of the indwelling needle 10, this invention is not limited to this. Without limitation, it can also be used as an indwelling needle for blood transfusion.

  In the indwelling needle 10 according to the first and second embodiments, the annular groove provided at intervals in the axial direction has been described as one configuration of the groove portion 28 provided on the outer peripheral surface of the inner needle body 20. As a modification of the groove portion 28 (see FIG. 3), a spiral groove that circulates at least a plurality of times on the outer peripheral surface of the inner needle main body 20 may be provided. Even with such a spiral groove, the ultrasonic wave is reflected toward the probe 52 and the position of the distal end portion of the inner needle 14 can be confirmed by the ultrasonic imaging device 50, similarly to the groove portion 28 described above.

  Further, the groove portion for reflecting the ultrasonic wave may be provided not only on the outer peripheral surface of the inner needle main body 20 but also on the inner peripheral surface of the outer needle main body 16. Thereby, even after the inner needle 14 is pulled out, the position near the tip of the outer needle 12 can be confirmed by the ultrasonic imaging apparatus 50.

  In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

DESCRIPTION OF SYMBOLS 10, 10a ... Indwelling needle 12 ... Outer needle 14, 14a ... Inner needle 16 ... Outer needle body 18 ... Outer needle hub 20 ... Inner needle body 22, 22a ... Inner needle hub 26 ... Fitting inner surface 30, 30a ... Fitting outer surface 32 ... Rib 36 ... Stopper 38 ... Engagement part 38A ... Step part

Claims (5)

An outer needle having a tubular outer needle body, and an outer needle hub provided at a proximal end portion of the outer needle body;
An inner needle body that can be inserted into the outer needle body, and an inner needle having an inner needle hub provided at a proximal end portion of the inner needle body,
The outer needle is provided with a fitting inner surface extending parallel to the axial direction,
The inner needle is provided with a fitting outer surface that extends in parallel with the axial direction and comes into contact with the fitting inner surface when the inner needle is attached to the outer needle,
The inner needle and the outer needle are fixed to each other by the frictional force between the fitting inner surface and the fitting outer surface.
An indwelling needle characterized by that. The indwelling needle according to claim 1,
The fitting inner surface is provided on the inner surface of the outer needle hub,
The fitting outer surface is provided on the outer surface of the inner needle hub,
An indwelling needle characterized by that. The indwelling needle according to claim 2,
On the outer surface of the inner needle hub, a plurality of ribs extending in the axial direction are provided at intervals in the circumferential direction, and the fitting outer surface is formed on the outer surface of the rib.
An indwelling needle characterized by that. In the indwelling needle according to any one of claims 1 to 3,
The inner needle hub is provided with a stopper that comes into contact with a predetermined portion of the outer needle hub when an insertion amount of the inner needle hub into the outer needle hub reaches a predetermined amount.
An indwelling needle characterized by that. In the indwelling needle according to any one of claims 1 to 4,
In the vicinity of the distal end portion of the inner needle main body, an engaging portion that is hooked on the distal end portion of the outer needle main body is provided.
An indwelling needle characterized by that.

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