JP5879062B2 - Indwelling needle assembly - Google Patents

Description

  The present invention relates to an indwelling needle assembly including an indwelling needle that is punctured into a blood vessel or the like and used for connection with an infusion line or the like.

  Conventionally, there is an indwelling needle that inserts an inner needle into an outer needle, guides the inner needle to puncture the outer needle into a blood vessel, etc., and then removes the inner needle and connects the infusion line to the placed outer needle. Are known. However, with the conventional indwelling needle, when the inner needle is removed from the outer needle, the patient's blood flows out from the outer needle placed in the blood vessel and adheres to the doctor or nurse, or the removed inner needle is attached to the doctor or nurse. In some cases, puncture may occur accidentally. At this time, if the patient is a patient with an infection such as HIV, the doctor or nurse may be affected by the attached blood or erroneous puncture.

  Therefore, an indwelling needle assembly is known that includes an inner needle, a case in which the inner needle is provided so as to be freely accessible, and a spring attached between the inner needle and the case (see, for example, Patent Document 1). In this indwelling needle assembly, when the inner needle protrudes from the case, the spring is locked by the stopper in a state where the spring is biased in the direction in which the inner needle is housed in the case. When the doctor or nurse directly operates the stopper to release the state where the spring is locked by the stopper, the inner needle is retracted by the elastic force of the spring and removed from the puncture site, and stored in the case. .

  According to this indwelling needle assembly, since the removed inner needle is stored in the case, it is possible to prevent erroneous puncture of the inner needle with respect to a doctor or a nurse.

JP 2004-49607 A

  However, according to the indwelling needle assembly of Patent Document 1, unless the doctor or nurse operates the stopper separately after puncturing and releases the state in which the spring is locked by the stopper, the internal force due to the elastic force of the spring There is an inconvenience that the needle retraction cannot be activated.

  An object of the present invention is to provide an indwelling needle assembly that can store an inner needle in a housing without requiring a special operation after puncturing, in view of the problems of the prior art.

An indwelling needle assembly according to the present invention includes a tubular outer needle, an outer needle base to which a proximal end portion of the outer needle is fixed, an inner needle that can be inserted into the outer needle and the outer needle base, and the inner needle. An inner needle base to which a base end portion of the inner needle base is fixed, a cylindrical housing for storing the inner needle base so as to be movable in an axial direction and a radial direction, the outer needle base being detachably held, and the housing A movable member that is movable from a predetermined first position to a second position in the needle tip direction of the outer needle, and a biasing member that biases the inner needle base toward the proximal end of the housing. The moving member is configured to prevent movement of the inner needle base in the radial direction in the housing when the moving member is in the first position; and the inner needle base when the moving member is in the second position. and a pressing portion which moves to press radially within the housing in a radial direction, the inner needle hub when said moving member is in the first position, the biasing member When the moving member is moved to the second position, the movement preventing portion is stopped in the radial direction and the moving member is moved to the second position. The movement prevention in the radial direction by the movement blocking part of the inner needle base is released, and the inner needle base is pressed in the radial direction in the casing by the pressing part and moved in the radial direction, thereby Is released, moved by the urging force of the urging member in the proximal direction of the housing, and the distal end portion of the inner needle is housed in the housing.

  According to the present invention, after holding the housing and puncturing the inner and outer needles on the target site, the moving member is moved to the second position with the thumb or forefinger of the hand holding the housing to move the outer needle. The inner needle base is released from the movement prevention in the radial direction by releasing only the forward movement, and is released from the locking with the casing, and is moved toward the proximal end of the casing by the urging member. The inner needle can be accommodated in the housing without requiring any special operation.

  In the present invention, the inner needle base includes a locked portion that is locked to the casing on the outer peripheral surface and a pressed portion that is pressed by the pressing portion of the moving member. A locking portion that locks the locked portion on an inner peripheral surface, and a support portion that supports the inner needle base at a position forward of the locking portion, and the biasing member includes the housing The movable member is sandwiched between a body support portion and the inner needle base, and the moving member is inserted into the casing and the proximal end side of the casing exceeds the proximal end portion of the inner needle base. The movement prevention part may be arranged on the opposite side of the pressing part across the inner needle base.

  According to this, it is necessary when the moving member is moved to the second position, and when the moving member is moved to the second position, the inner needle base is locked at the front position of the housing and is prevented from moving in the radial direction. Further, the release of the movement prevention in the radial direction and the release of the engagement with the housing can be realized with a simple configuration.

  Further, in the present invention, when the moving member is moved from the first position to the second position, a removal preventing mechanism that prevents the moving member from coming out of the housing, and the moving member is in the second position. And a return preventing mechanism for preventing the moving member from returning toward the first position after being moved.

  According to this, it is possible to prevent the moving member from falling out of the housing and damaging the puncture site, or the moving member returning toward the first position to expose the inner needle from the tip of the moving member. .

It is a disassembled perspective view of the indwelling needle assembly which concerns on one Embodiment of this invention. It is a figure which shows the detail of the inner needle base in the indwelling needle assembly of FIG. It is a figure which shows the detail of the stopper in the indwelling needle assembly of FIG. It is a figure which shows the detail of the case in the indwelling needle assembly of FIG. It is a figure which shows the detail of the outer cylinder in the indwelling needle assembly of FIG. It is sectional drawing which shows a mode when the case in the indwelling needle assembly of FIG. 1 moves. It is a figure which shows a mode when the overhang | projection part of the case in the indwelling needle assembly of FIG. 1 gets over the return prevention part of an outer cylinder. It is a figure which shows another example of the operation part in the indwelling needle assembly of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of an indwelling needle assembly according to an embodiment of the present invention.

  As shown in FIG. 1, an indwelling needle assembly 1 includes an indwelling part 2 to be indwelled at a target site, an inner needle 3 to be inserted into the indwelling part 2, and an inner needle to which a proximal end portion of the inner needle 3 is fixed. A base 4, a housing 5 that stores and holds the inner needle base 4 movably in the axial direction and the radial direction, and a second position on the distal end side of the distal end portion of the housing 5 from a predetermined first position And a compression spring 7 that urges the inner needle base 4 toward the proximal end of the housing 5.

  The case 6 constitutes a moving member in the present invention. The compression spring 7 constitutes an urging member in the present invention. As will be described later, the first position is the position of the case 6 in FIG. 6A, and the second position is the position of the case 6 in FIGS. 6C and 6D.

  The indwelling unit 2 includes a tubular outer needle 21 and an outer needle base 22 to which a proximal end portion of the outer needle 21 is fixed. The outer needle 21 includes a shaving bamboo-like puncture portion 21a at the tip. The inner needle 3 is inserted into the outer needle 21 and the outer needle base 22 so that the tip protrudes from the tip of the outer needle 21. The housing 5 includes an outer cylinder 8 and a stopper 9 fixed to the outer cylinder 8. A protector 10 is attached to the distal end portion of the housing 5 to protect the indwelling portion 2 and the inner needle 3.

  FIG. 2 shows details of the inner needle base 4. 2 (a) is a plan view, FIG. 2 (b) is a front view, FIG. 2 (c) is a left side view, FIG. 2 (d) is a right side view, and FIG. 2 (e) is FIG. 2 (c). AA sectional view, and FIG. 2F are BB sectional views of FIG. 2B.

  As shown in FIG. 2, the inner needle base 4 is adjacent to the proximal end side of the hollow cylindrical inner needle fixing portion 41 into which the inner needle 3 is inserted and fixed, and the inner needle fixing portion 41. A hollow cylindrical puncture confirmation portion 42 having a diameter larger than that of the portion 41 and a hollow cylindrical filter insertion portion 43 adjacent to the proximal end side of the puncture confirmation portion 42 and having a diameter larger than that of the puncture confirmation portion 42 are provided. A portion that transitions from the inner needle fixing portion 41 to the puncture confirmation portion 42 is a stepped portion 44 that is pressed by the compression spring 7.

  On the upper side of the side surface of the filter insertion portion 43, a protrusion 45 is provided that is pushed downward by the case 6 when the case 6 is moved from the first position to the second position. The protrusion 45 is provided with an inclined surface for enabling the pressing. The protrusion part 45 comprises the to-be-pressed part in this invention.

  A groove 46 is provided above the side surface of the puncture confirmation unit 42. The groove 46 extends along a direction orthogonal to the axis of the inner needle base 4. Of the inner surfaces on both sides constituting the groove portion 46, the surface on the distal end side of the inner needle base 4 is a supported surface 46 a supported by the stopper 9. The supported surface 46a constitutes a locked portion in the present invention.

  As shown in FIG. 2 (f), the side surfaces on both sides in the left-right direction of the puncture confirmation unit 42 have a shape that is slightly cut at a cut surface extending in the vertical direction parallel to the axis of the inner needle base 4. This is to make the indwelling needle assembly 1 compact. The groove 46 extends from the one cut surface to the other cut surface.

  The periphery of the puncture confirmation unit 42 is made of a transparent member so that the blood flashback generated in the puncture confirmation unit 42 can be visually recognized. A filter (aeration plug) 47 (FIG. 1) that allows only gas to pass and suppresses passage of liquid is inserted into the filter insertion portion 43.

  FIG. 3 shows details of the stopper 9. 3 (a) is a top view, FIG. 3 (b) is a front view, FIG. 3 (c) is a bottom view, FIG. 3 (d) is a left side view, FIG. 3 (e) is a right side view, and FIG. f) is an AA cross-sectional view of FIG. 3 (d), FIG. 3 (g) is a BB cross-sectional view of FIG. 3 (b), and FIG. 3 (h) is a CC cross-section of FIG. 3 (b). FIG.

  As shown in FIG. 3, the stopper 9 includes a convex portion 91 that fits into the groove portion 46 of the inner needle base 4, a semicylindrical semicylindrical portion 92 that is adjacent to the distal end side of the stopper 9 of the convex portion 91, and a semicylindrical shape. The support part 93 which comprises the front end surface of the part 92, and supports the front end side of the inner needle base 4, the partial cylindrical part 94 adjacent to the stopper 9 base end side of the convex part 91, and the base end face of the housing 5 are formed. A disc-shaped base end member 95 and a connecting portion 96 for connecting the partial cylindrical portion 94 and the base end member 95 to each other.

  The semi-cylindrical part 92 covers the upper half of the tip side of the groove part 46 of the inner needle base 4. The connecting portion 96 constitutes the upper portion of the housing 5 in the existence range. As shown in FIG. 3 (h), the partial cylindrical portion 94 constitutes from the upper portion of the housing 5 to the right half in the vertical direction when viewed in the base end direction of the housing 5.

  The support portion 93 can move the inner needle base 4 in the radial direction so that the inner needle base 4 can be removed in the proximal direction, and the proximal end side of the inner needle base 4 can swing from the predetermined support position to the support release position. The tip side of the inner needle base 4 is supported. As will be described later, when the inner needle base 4 swings to the support release position, the inner needle base 4 is removed from the support portion 93 by the urging force of the compression spring 7.

  The convex part 91 has a shape suitable for fitting with the groove part 46 of the inner needle base 4 as shown in FIG. The surface of the convex portion 91 on the distal end side of the stopper 9 is a support surface 91 a that supports the supported surface 46 a of the inner needle base 4. The support surface 91a supports the supported surface 46a against the urging force of the compression spring 7 when the inner needle base 4 is located at the above-described support position, and the inner needle base 4 swings to the above-described support release position. It is formed so that the support is released when it is moved. The support surface 91a constitutes a locking portion in the present invention.

  The support portion 93 is provided at the end portion on the front end side of the stopper 9 and is configured as a partially annular and flat plate-like member having an open lower end. The axis of the ring coincides with the axis of the housing 5. The outer diameter and inner diameter of the semi-cylindrical portion 92 are smaller than the outer diameter and inner diameter of the partial cylindrical portion 94, respectively. The inner diameter of the semi-cylindrical portion 92 is approximately the same as the outer diameter of the puncture confirmation portion 42 of the inner needle base 4.

  FIG. 4 shows details of the case 6. 4 (a) is a top view, FIG. 4 (b) is a front view, FIG. 4 (c) is a left side view, FIG. 4 (d) is a right side view, and FIG. 4 (e) is FIG. 4 (c). AA sectional view and FIG. 4F is a part of the BB sectional view of FIG.

  As shown in FIG. 4, the case 6 includes a hollow cylindrical outer needle base mounting portion 61 to which a base end portion of the outer needle base 22 is fitted and removably attached, and a base end of the outer needle base mounting portion 61. A cylindrical portion 62 of a hollow cylindrical shape adjacent to the side and fitted with the semi-cylindrical portion 92 of the stopper 9; a partially cylindrical swing preventing portion 63 adjacent to the proximal end side of the cylindrical portion 62; And an operation unit 64 for moving the case 6 from the first position to the second position. The rocking | fluctuation prevention part 63 blocks | prevents the movement of the inner needle base 4 to the radial direction, and comprises the movement prevention part of this invention.

  The rocking | fluctuation prevention part 63 prevents the above-mentioned rocking | fluctuation (movement to radial direction) when the case 6 is located in a 1st position, and cancels this prevention when the case 6 moves to a 2nd position. Formed. For this purpose, the inner surface of the rocking prevention portion 63 has a semi-cylindrical shape that covers the right side of the side surface of the filter insertion portion 43 of the inner needle base 4 as viewed in the distal direction of the inner needle base 4; The filter insertion portion 43 has a diameter substantially equal to the outer diameter.

  When the case 6 moves to the second position, the base end side of the rocking prevention portion 63 comes into contact with the protruding portion 45 of the inner needle base 4 and pushes the protruding portion 45 downward. The pressing part 65 which produces the rocking | fluctuation of is provided. The pressing portion 65 constitutes a drop prevention mechanism in cooperation with the convex portion 91 of the stopper 9. That is, the pressing portion 65 contacts the convex portion 91 of the stopper 9 when the case 6 is moved from the first position to the second position, and prevents the case 6 from falling off the housing 5.

  That is, in the case 6, the pressing portion 65 is inserted into the housing 5 and is disposed on the proximal end side of the housing 5 beyond the proximal end portion of the inner needle base 4, and the swing preventing portion 63 is disposed on the inner needle base 4. It is arrange | positioned on the opposite side of the press part 65 on both sides.

  The upper surface of the operation unit 64 is a surface whose front end is slightly warped upward so that the case 6 can be easily pushed toward the front end of the housing 5 with the thumb or index finger of the hand holding the housing 5. The operation portion 64 and the cylindrical portion 62 are coupled via a coupling portion 66 having the same length as the cylindrical portion 62 and a constant lateral width. However, a protruding portion 67 protruding to the left side is provided at the rear end portion of the left side surface of the coupling portion 66 when viewed in the front end direction of the case 6.

  When the case 6 is moved from the first position to the second position, the overhang portion 67 prevents the return to the first position in cooperation with a return prevention portion 82 of the outer cylinder 8 described later. Therefore, the first position side of the overhang portion 67 is a surface perpendicular to the moving direction, and the second position side is an inclined surface.

  FIG. 5 shows details of the outer cylinder 8. 5A is a plan view, FIG. 5B is a front view, and FIG. 5C is a right side view. As shown in FIG. 5, the outer cylinder 8 has a hollow cylindrical shape without a bottom surface and a top surface. However, the upper portion of the outer cylinder 8 is a slit portion 81 that is open in a slit shape from the base end to the tip end.

  The front end side of the slit portion 81 has a width equivalent to the lateral width of the coupling portion 66 of the case 6, and serves as a guide portion 81 a that guides the coupling portion 66 from the first position to the second position. The portion of the slit portion 81 adjacent to the proximal end side of the guide portion 81 a has a certain width that matches the width of the connecting portion 96 of the stopper 9.

  A return prevention portion 82 that constitutes a return prevention mechanism in cooperation with the overhang portion 67 of the case 6 described above is provided on the distal end side of the slit portion 81. The return prevention portion 82 is formed by cutting from the slit portion 81 and is configured as a portion protruding into the slit portion 81 at the free end of the cantilever-like portion extending in the length direction of the slit portion 81. As a result, the return preventing portion 82 is elastically pressed by the protruding portion 67 of the case 6 and can be returned when the case 6 moves from the first position to the second position.

  The surface on the base end side of the outer cylinder 8 of the return preventing portion 82 is an inclined surface so that the overhang portion 67 can easily get over. The surface of the return prevention portion 82 on the front end side of the outer cylinder 8 is a surface perpendicular to the axis of the outer cylinder 8 so as to prevent the overhanging portion 67 that has passed over from returning to the base.

  The indwelling needle assembly 1 is assembled as follows. That is, as understood from FIGS. 1 to 5, first, while compressing the compression spring 7, one end of the compression spring 7 presses the stepped portion 44 of the inner needle base 4, so that the inner needle of the inner needle base 4 is pressed. Attach to the fixed portion 41.

  Next, the stopper 9 is attached to the inner needle base 4 from above. That is, the inner needle fixing portion 41 is fitted to the support portion 93 at the tip of the stopper 9, the support portion 93 presses the other end of the compression spring 7, and the convex portion 91 of the stopper 9 is formed in the groove portion 46 of the inner needle base 4. A stopper 9 is arranged with respect to the inner needle base 4 so as to be fitted. At this time, the support surface 91 a of the stopper 9 supports the supported surface 46 a of the inner needle base 4 against the urging force of the compression spring 7.

  Thereby, the distal end side of the inner needle base 4 is supported by the support portion 93 so that the proximal end side of the inner needle base 4 can swing downward. However, the base end side of the inner needle base 4 is fixed to the stopper 9 because the supported surface 46a is supported by the support surface 91a.

  Next, the semi-cylindrical portion 92 of the stopper 9 is fitted into the cylindrical portion 62 of the case 6 in a state where the case 6 is rotated about 90 ° clockwise from the posture state of FIG. The stopper 9 is moved in the proximal direction from the distal end side so as to match. When the support portion 93 at the distal end of the stopper 9 reaches the distal end side end portion of the cylindrical portion 62 of the case 6, the case 6 is rotated about 90 ° counterclockwise toward the distal end side.

  As a result, the case 6 is attached to the stopper 9 at the first position. At this time, the swing preventing portion 63 of the case 6 covers the right side of the filter insertion portion 43 of the inner needle base 4 toward the distal end side, and the filter insertion portion 43 swings downward about the support portion 93. It will be in the state which blocked.

  Further, the pressing portion 65 is in a state of facing the protruding portion 45 of the inner needle base 4 positioned in the distal end direction and the convex portion 91 of the stopper 9 behind the inner side of the stopper 9. Further, the tip of the inner needle fixing portion 41 of the inner needle base 4 is slightly protruded from the tip of the outer needle base attaching portion 61 of the case 6.

  Next, an adhesive is applied to the proximal end portion of the inner needle 3, and the proximal end portion is inserted into the inner needle fixing portion 41 of the inner needle base 4 and bonded. Then, silicon is applied to the inner needle 3. Further, it is confirmed that the inner needle 3 is not clogged. Further, the above-described filter (aeration plug) 47 is inserted into the filter insertion portion 43 of the inner needle base 4.

  Next, the cylindrical portion 62 is inserted into the proximal end portion of the outer tube 8 from the distal end side, and the outer tube 8 is moved to the case 6 and the stopper 9 until the proximal end of the outer tube 8 contacts the proximal end member 95 of the stopper 9. Slide against. At this time, the coupling portion 66 of the case 6 and the connecting portion 96 of the stopper 9 are guided by the slit portion 81 of the outer cylinder 8.

  When the base end of the outer cylinder 8 comes into contact with the base end member 95 of the stopper 9, a solvent is applied between the base end of the outer cylinder 8 and the base end member 95 to couple the outer cylinder 8 and the stopper 9. Thereby, mounting | wearing of the outer cylinder 8 is completed and the case 6 will be in the state located in the 1st position.

  Next, the indwelling part 2 is attached to the case 6 by fitting the outer needle base attaching part 61 of the case 6 to the outer needle base 22 of the indwelling part 2. Further, the protector 10 is attached to the outer cylinder 8 by inserting the distal end of the outer cylinder 8 into the base end of the protector 10. Thereby, the assembly of the indwelling needle assembly 1 is completed.

  When using the indwelling needle assembly 1, first, the protector 10 is removed from the indwelling needle assembly 1 to expose the outer needle 21. Then, it is confirmed that the outer needle base 22 is securely attached to the outer needle base attaching portion 61 of the case 6. Next, the housing 5 is held, and the inner needle 3 and the outer needle 21 are punctured into the target site of the blood vessel. At this time, the puncture of the inner needle 3 and the outer needle 21 into the blood vessel can be confirmed by the occurrence of flashback of blood in the puncture confirmation unit 42 of the inner needle base 4.

  Since the proximal end portion of the inner needle base 4 is blocked by a filter (aeration plug) 47 inserted in the filter insertion portion 43, blood does not flow out from the proximal end portion of the inner needle base 4. And the backflow of blood to the tip side is limited.

  Next, the outer needle 21 and the inner needle 3 are laid down so that the puncture angle with respect to the blood vessel is reduced, and further, it is sent into the blood vessel by about several mm. Next, by pushing the operation unit 64 with the thumb or index finger of the hand holding the housing 5, only the outer needle 21 is further delivered into the blood vessel. At this time, the case 6 moves from the first position to the second position.

  FIG. 6 is a cross-sectional view showing a state when the case 6 moves from the first position to the second position. When the case 6 is located at the first position, as shown in FIG. 6A, the inner needle base 4 is supported by the support portion 93 of the stopper 9 so that the distal end side of the inner needle fixing portion 41 can swing. 9 is supported by the support surface 91 a of the inner needle base 4 through the supported surface 46 a against the urging force of the compression spring 7. Further, since the rocking prevention portion 63 of the case 6 covers the lower half of the filter insertion portion 43 toward the right end side, the filter insertion portion 43 is prevented from rocking downward.

  In this state, when the case 6 is moved from the first position in FIG. 6A toward the distal end as described above and reaches the vicinity of the second position, as shown in FIG. Moves out of the position of the filter insertion part 43 and moves to the position of the puncture confirmation part 42 having a smaller diameter than the filter insertion part 43. As a result, the prevention of the swing of the inner needle base 4 by the swing preventing portion 63 is released.

  When the case 6 reaches the second position, the pressing portion 65 of the case 6 comes into contact with the protruding portion 45 of the inner needle base 4 and presses the protruding portion 45 as shown in FIG. As a result, the inner needle base 4 swings around the support portion 93 of the stopper 9, and the filter insertion portion 43 of the inner needle base 4 is displaced downward. Along with this, the support surface 91a of the stopper 9 is displaced downward and deviates from a position where the supported surface 46a of the inner needle base 4 can be supported. Thereby, the support of the supported surface 46a by the support surface 91a is released.

  As a result, as shown in FIG. 6D, the compression spring 7 is extended, and the inner needle base 4 is moved until it contacts the proximal end member 95 of the stopper 9. Accordingly, the inner needle 3 fixed to the inner needle base 4 is pulled out from the outer needle 21 and accommodated in the housing 5.

  When the case 6 reaches the second position, the pressing portion 65 of the case 6 comes into contact with the convex portion 91 of the stopper 9 as shown in FIG. 6C, so that further movement of the case 6 is prevented. . Further, when the case 6 reaches the second position, the overhanging portion 67 of the case 6 gets over the return preventing portion 82 of the outer cylinder 8. As a result, as shown in FIG. 7, the case 6 base end side end surface of the overhanging portion 67 faces the case 6 front end side end surface of the return preventing portion 82, and thus the case 6 that has reached the second position is It is impossible to return to the direction of one position.

  Thereafter, by removing the outer needle base attachment portion 61 of the case 6 from the outer needle base 22, the outer needle 21 with the outer needle base 22 can be placed in the target site. By connecting an infusion line or the like to the indwelling outer needle base 22, treatment such as infusion is performed.

  As described above, according to the present embodiment, after holding the casing 5 and puncturing the inner needle 3 and the outer needle 21 in the target site, the operation unit is operated with the thumb or index finger of the hand holding the casing 5. By pushing 64 and only sending the outer needle 21 further into the blood vessel, the prevention of the swinging of the inner needle base 4 is released, and the inner needle base 4 swings, whereby the pressing spring 7 (biasing member) is moved. The support of the resisting inner needle base 4 is released, the inner needle base 4 is moved in the proximal direction by the pressing spring 7, and the inner needle 3 is accommodated in the housing 5. Therefore, the inner needle is not required to be operated. 3 can be stored in the housing 5.

  Further, the housing 5 is constituted by an outer cylinder 8 and a stopper 9 fixed to the outer cylinder 8 and provided with a support portion 93 and a support surface 91a, and the pressing spring 7 has a case 6 (moving member) in a first position. Since the stopper 9 is interposed between the inner surface of the support portion 93 and the inner needle base 4, the inner needle base is supported by the compression coil spring 7 between the support portion 93 and the support surface 91a. 4 can be held.

  Then, the case 6 and the outer cylinder 8 can be easily assembled. Therefore, the indwelling needle assembly 1 can be easily assembled.

  In addition, when the case 6 is moved from the first position to the second position, the case 6 is prevented from being detached from the housing 5, and after the case 6 is moved to the second position, the case 6 is moved to the second position. Since a return prevention mechanism is provided to prevent returning to the first position, the case 6 falls off the housing 5 after puncturing the target site and damages the punctured site, or the case 6 returns to the first position. Thus, the outer needle 21 can be prevented from coming off from the puncture site.

  The present invention is not limited to the above embodiment. For example, in the above description, as the operation unit for moving the case 6 to the second position, the operation unit 64 having the upper surface with the tip side slightly warped upward is used, but instead, an operation as shown in FIG. The part 83 may be adopted. FIG. 8A is a top view of the operation unit 83, and FIG. 8B is a front view. As shown in FIG. 8, the operation unit 83 includes a front end side operation surface 83a and a rear end side operation surface 83b. The operation surfaces 83a and 83b have shapes that warp upward from the front end and the rear end of the operation portion 83 to the center portion.

  DESCRIPTION OF SYMBOLS 1 ... Indwelling needle assembly, 2 ... Indwelling part, 3 ... Inner needle, 4 ... Inner needle base, 5 ... Housing, 6 ... Case (moving member), 7 ... Compression spring (urging member), 8 ... Outer cylinder , 9 ... Stopper, 21 ... Outer needle, 22 ... Outer needle base, 45 ... Projection (pressed part), 46a ... Supported surface (locked part), 63 ... Swing prevention part (movement prevention part), 64, 83 ... operation part, 65 ... pressing part, 91a ... support surface (locking part), 93 ... support part.

Claims (3)

A tubular outer needle and an outer needle base to which a proximal end portion of the outer needle is fixed;
An inner needle that can be inserted into the outer needle and the outer needle base, and an inner needle base to which a proximal end portion of the inner needle is fixed;
A cylindrical housing for accommodating the inner needle base movably in the axial direction and the radial direction;
A movable member that detachably holds the outer needle base and is movable from a predetermined first position to a second position in the needle tip direction of the outer needle with respect to the housing;
A biasing member that biases the inner needle base toward the proximal end of the housing;
The moving member includes a movement preventing unit that prevents the inner needle base from moving in the radial direction in the housing when in the first position, and the inner needle base when in the second position. A pressing portion that moves in the radial direction by pressing in the body in the radial direction,
When the moving member is in the first position, the inner needle base is locked at the front position of the housing against the urging force of the urging member, and is radially moved by the movement preventing portion. Movement to
When the moving member is moved to the second position, the movement prevention part of the inner needle base in the radial direction by the movement prevention part is released, and the inner needle base is radially moved in the casing by the pressing part. And is moved in the radial direction to be released from the engagement with the housing , moved by the urging force of the urging member in the proximal direction of the housing, and the distal end portion of the inner needle is An indwelling needle assembly that is housed in a housing. The inner needle base is formed with a locked portion locked to the housing on the outer peripheral surface and a pressed portion pressed by the pressing portion of the moving member,
The housing is formed with a locking portion that locks the locked portion on an inner peripheral surface, and a support portion that supports the inner needle base at a position ahead of the locking portion,
The biasing member is sandwiched between a support portion of the housing and the inner needle base,
The moving member is disposed on the proximal end side of the housing beyond the proximal end portion of the inner needle base when the pressing portion is inserted into the housing, and the movement blocking portion sandwiches the inner needle base. The indwelling needle assembly according to claim 1, wherein the indwelling needle assembly is disposed on an opposite side of the pressing portion.   When the moving member is moved from the first position to the second position, a removal preventing mechanism that prevents the moving member from coming out of the housing; and after the moving member is moved to the second position, The indwelling needle assembly according to claim 1, further comprising a return prevention mechanism that prevents the moving member from returning toward the first position.

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