JP3782554B2 - Needle assembly - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is an assembly having a first needle and a second needle that can be inserted into the first needle, wherein the first needle is provided with a rearward projecting member projecting rearward at a rear end portion. And the second needle has a hub provided with a forward projecting member projecting forward at the rear end, and allows one of these members to be inserted into the other member. The present invention relates to a needle assembly provided with a grip forming portion that engages with each other on the outer surface of a member and the inner surface of the other member.
[0002]
More particularly, the present invention relates to an epidural needle-spinal needle assembly.
[0003]
[Prior art]
The spinal needle-epidural needle assembly is used to administer spinal and epidural anesthetic fluids. Usually, an epidural needle is inserted into the epidural space. Thereafter, the spinal needle is inserted through the epidural needle until the tip of the spinal needle is inserted into the spinal dura mater and enters the intrathecal space. A spinal anesthetic solution is administered to the device end of the spinal needle, particularly via the spinal needle, to produce a rapid and short anesthesia block. Next, the spinal needle is removed while leaving the epidural needle in place. In this state, the epidural catheter is inserted into the epidural needle and the patient side end of the epidural catheter is positioned in the epidural space. Thereafter, the epidural needle is removed while leaving the catheter in place, and an anesthetic fluid is administered to the epidural space as necessary to produce a long-lasting anesthetic effect.
[0004]
[Problems to be solved by the invention]
When the tip of the spinal needle is properly inserted, its position should be maintained during administration of the anesthetic fluid. However, this is difficult. That is, the epidural needle is held relatively firmly by frictional contact with the inserted tissue, but the spinal needle only engages with the epidural needle hole with a relatively low frictional force. is there. The anesthesiologist must hold the spinal needle while connecting the spinal needle to the syringe and during spinal anesthesia administration. If the needle slips, there is a risk that the spinal needle will break through the end wall of the subarachnoid space or pull back to the epidural space.
[0005]
Various proposals have been made to secure the spinal needle to the epidural needle after the spinal needle has been properly inserted. In Anesthesia 1990, No. 45, pages 593-594 and Acta Anessesiologica Scand, 1994, No. 38, pages 439-441, J Simsa is the hub of the epidural needle. The metal screw clamp to be attached is described, and this screw clamp is fixed in place. European Patent Publication No. 564859 describes an assembly for connecting the spinal needle to the hub of the epidural needle to lock it together, but the spinal needle and epidural needle are only in one position. It cannot be fixed. European Patent No. 696437 describes an assembly in which a spinal needle hub is provided with an elastic locking tab that is engaged between a series of teeth formed on an extension of the epidural needle hub. This configuration requires the user to hold the tab in the released position while inserting the spinal needle. Furthermore, there is a limit to the accuracy with which the space between the teeth can lock the spinal needle in place.
[0006]
It is an object of the present invention to obtain an improved needle assembly.
[0007]
[Means for Solving the Problems]
According to the needle assembly of the present invention, one of the grip forming portions is provided with an elastic member, and the other grip forming portion is arranged in parallel with each other along the members corresponding to the other grip forming portion. The first and second elongated regions are provided, the elastic member is accommodated in the first elongated region, and the elastic member is slidably fitted along the length of the first elongated region. In the region, when the two members are twisted together, the elastic member slides in the lateral direction, but the elastic member is prevented from moving in the longitudinal direction along the second elongated region. A surface forming portion that locks the relative longitudinal movement of the member is provided.
[0008]
It is preferable that the surface forming portion is provided by a series of ribs extending in the lateral direction in parallel with each other in the second elongated region. The series of ribs includes long ribs and short ribs arranged alternately. It is preferable that the rear projecting member can be inserted into the front projecting member. After locking the two needles in the longitudinal relative movement, it is preferable to allow the two needles to rotate relative to each other within a limited range. The rear projecting member is constituted by a cylindrical sleeve, and the sleeve is rotatable within a limited range with respect to the hub of the first needle. It is preferable that the elastic member is shorter than the second elongated region. It is preferable that the elastic member is provided on the inner surface of the other member.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, preferred embodiments of the present invention will be described with reference to the drawings.
[0010]
Referring first to FIG. 1, the assembly includes an epidural needle assembly 1 and a spinal needle assembly 2 that is attached to the epidural needle at various different longitudinal positions. It can be locked to the assembly 1.
[0011]
The epidural needle assembly 1 has a normal Tuohy epidural needle 10 with a plastic hub 11 at the rear end. A rear end of the hub 11 of the epidural needle has a cylindrical insertion port 12 protruding rearward, and a peripheral groove 13 is provided around an intermediate portion of the length of the insertion port 12. A short stop 14 is projected rearward from the rear surface of the square flange 15 at the front end of the insertion slot 12. The epidural needle assembly 1 is formed by a cylindrical sleeve 16 of a rigid plastic material, and this sleeve 16 is snap-fitted into the slot 12. The sleeve 16 is provided with an internal rib 17 at a position engaging with the groove 13 of the insertion slot 12 to lock the movement of the sleeve in the longitudinal direction, but it can be rotated around the insertion slot. A groove 18 is formed around the inner surface of the front end of the sleeve 16 to accommodate the flange stop 14, but this groove 18 is formed about 180 ° around the sleeve to allow rotation about the inlet 12. Limit to groove range. The outer surface of the sleeve is provided with two elongate regions 20, 21 juxtaposed with each other in the longitudinal direction along the length of the sleeve. One first elongated region 20 is smooth and has a slightly smaller radius than the rest of the sleeve to form a shallow longitudinal channel (channel). The grip region 21, which is the other second elongated region, is continuous with the first region 20. The grip region 21 includes a plurality of parallel shallow grip ribs 22 extending in the circumferential direction across the region 21. Provide an outwardly projecting surface of the type. The rib 22 has a triangular outline with sharp tips and a height of about 0.25 mm. The ribs 22 are alternately arranged with short ribs and long ribs at a pitch of 0.5 mm.
[0012]
The spinal needle assembly 2 is provided with a normal spinal needle 30 and a normal type hub 31, and a shallow cylindrical collar 32 is fixed to the hub 31 and protrudes forward of the hub. The length of the collar 32 is the same as the length of the sleeve 16, the inner diameter of the collar is the same as the outer diameter of the sleeve, and the sleeve 32 is closely slidably fitted to the sleeve. The collar 32 carries a small grip pad 33 and this grip pad 33 is disposed in a shallow recess 34 (see FIG. 6) on the inner surface of the front end of the collar. The grip pad is formed of natural rubber, polyurethane, or any other material to grip the rib. The pad 33 is held in place by an elongated head 35 of the pad 33, and this head 35 is snap-fitted into a through hole 36 formed in the wall of the collar. Alternatively, the pad can be molded directly into the collar by injection molding with a material having a low melting temperature. The thickness of the pad 33 and the depth of the recess 34 are selected so that the inner surface of the pad protrudes beyond the inner surface of the collar. A hump 37 is provided on the outer surface of the collar 32 to improve grip.
[0013]
In use, the epidural needle 10 is inserted into the epidural space as usual. Next, the spinal needle 30 is inserted into the epidural needle 10 through the hub 11 of the epidural needle assembly. When the front end of the collar 32 approaches the rear end of the sleeve 16, the user rotates the sleeve clockwise enough to abut the stop 14 so that the spinal needle 30 is in contact with the elastic gripping pad 33. Make sure that the smooth channel 20 of the sleeve 16 is aligned. In this orientation, the spinal needle assembly 2 can be freely slid into the epidural needle assembly 1 to assume the required position shown in FIGS. The ribs 22 in the sleeve 16 conveniently function as depth markers, and a numerical value can be printed beside the ribs in the channel 20. When the spinal needle assembly 2 is inserted to the required position, as shown in FIGS. 4, 5 and 6, the spinal needle assembly is simply hardened by twisting it over the epidural needle assembly at 45 °. It can be locked in place on the outer needle assembly. At this time, the elastic pad 33 moves laterally from the smooth channel 20 and is aligned with the rib 22, and the rib 22 bites into and holds the lower surface of the pad. The circumferential orientation of the ribs 22 allows the pad 33 to move laterally along the length of the ribs, but prevents it from moving longitudinally across the ribs, and thus the spinal needle set. The solid 2 is locked in the longitudinal direction relative to the epidural needle assembly 1. Since the sleeve 16 can rotate with respect to the hub 11 of the epidural needle assembly, the spinal needle assembly 2 can be rotated counterclockwise over 180 ° without releasing the locking by the pad 33. . When the spinal needle assembly 2 needs to be removed, the spinal needle assembly 2 is twisted through 180 ° until the stop 14 prevents the sleeve 16 from rotating. At this time, the collar 32 is further twisted counterclockwise by 45 °, and the pad 33 is moved laterally with respect to the ribbed region 21 to align it with the smooth channel 20, thereby moving the spinal needle assembly 2 backwards. Can be pulled out of the epidural needle assembly 1.
[0014]
By gripping between the elastic pad and the rib, it can be locked in any longitudinal position, thus allowing a stepless variable positioning of the spinal needle relative to the epidural needle.
[0015]
The elastic pad 33 is made shorter than the length of the collar 32 so that the entire length of the pad is gripped by the gripping ribs 22 at any longitudinal position except for the rearmost position of the collar relative to the sleeve. The same force is required to lock and unlock the two assemblies 1, 2 at all longitudinal positions. As an alternative, elastic pads can be provided along the entire length of the collar. According to such a configuration, a fixed locking force can be obtained by providing a gripping rib only along a short portion of the rear end of the sleeve, and the same number of ribs at all longitudinal positions of the collar. Causes gripping. For example, other modifications are possible, and an elastic member can be provided on the outer surface of the inner lock member instead of being provided on the inner surface of the outer lock member. According to such a configuration, ribs or other gripping surface forming portions are provided on the inner surface of the outer lock member.
[0016]
According to the configuration described above, the sleeve 16 having the gripping region 21 can rotate over a range about the hub 11 of the epidural needle assembly, and the spinal needle 30 can be oriented in the required orientation. . Although this has some advantages, when locking and unlocking the collar 32, the sleeve 16 must be rotated in both directions over a maximum range. If the sleeve 16 is already fully rotated in the locking direction when the collar 32 is slid into place, this means that the collar must be twisted over a relatively small angle to lock. However, for unlocking, the user can twist the collar 32 and rotate the sleeve 16 in the opposite direction for the entire stroke before releasing the collar from the sleeve. The need to rotate the collar over different angles to lock and unlock can be confusing to the user.
[0017]
In the configuration shown in FIGS. 7 and 8, the sleeve 16 'is locked to the slot 12' so as to be prevented from rotating relative to the slot 12 '. In particular, the slot 12 ′ has a radially projecting rib 40 which is located in a corresponding recess 41 on the inner surface of the sleeve 16 ′. The outer surface of the insertion opening 12 'and the inner surface of the sleeve 16' have corresponding tapers, and the engagement ring is tightly fitted to the insertion opening and snap-fitted to prevent axial movement after assembly. 42 and a depression 43 are provided. An inwardly projecting flange 44 is provided at the rear end of the collar 32 'that snaps to a channel 45 formed around the outer surface of the front end of the hub 31' of the spinal needle assembly. Mating. Engaging the flange 44 with the channel 45 allows the spinal needle assembly 2 'to rotate relative to the collar 32'. The hub 31 'of the spinal needle assembly is cylindrical and has a circular cross section and is provided with a protrusion 46 projecting radially outward. Since this projection 46 is secured to the hub 31 ', the projection 46 indicates the orientation of the spinal needle 30' and the hub of the stylet assembly so that the stylet is accurately oriented at the tip of the spinal needle. It can also be arranged in the slot 47 at 48 (only the hub is shown). The stylet assembly hub 48 is press fitted onto the rear end of the spinal needle assembly hub 31 '.
[0018]
In use, the user holds the spinal needle assembly 2 'in the portion of the collar 32', aligns the collar 32 'with the sleeve 16' and slides the spinal needle assembly forward to the required position, as described above. To be able to. When this required position is reached, the collar 32 ′ is twisted approximately 45 ° so that the pad is engaged with the gripping area of the sleeve 16. In this way, with the spinal needle assembly 2 'locked against axial movement relative to the epidural needle assembly 1', the spinal needle assembly hub 31 'is gripped against the collar 32'. The spinal needle can be rotated to the required position by twisting. To remove the spinal needle assembly 2 ', it is only necessary to twist back the collar 32' through the same angle, thereby releasing the grip and allowing the spinal needle assembly to be withdrawn from the epidural needle assembly. According to this configuration, locking and unlocking can be caused by twisting over the same angle.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a needle assembly according to the present invention.
FIG. 2 is a perspective view of the needle assembly in an unlocked state.
FIG. 3 is a cross-sectional view of the needle assembly in an unlocked state.
FIG. 4 is a perspective view of the needle assembly in a locked state.
FIG. 5 is a longitudinal sectional view of the hub of the needle assembly in a locked state.
6 is an enlarged partial longitudinal sectional view of a part of FIG. 5. FIG.
FIG. 7 is an exploded perspective view of a needle assembly according to another embodiment.
8 is a longitudinal sectional view of the hub portion of the embodiment of FIG. 7 in a locked state.
[Explanation of symbols]
1,1 ′ epidural needle assembly
2,2 ′ Spinal needle assembly
10,10 ′ epidural needle
11,11 ′ Epidural needle hub
12,12 ′
13 peripheral groove
14 Stop
15 Flange
16,16 ′ sleeve
17 Internal rib
18 groove
20 First elongated region
21 2nd elongated area (grip area)
22 Ribs
30,30 ′ Spinal needle
31,31 ′ hub
32,32 ′ color
33 Grip pad
34 depression
35 heads
36 Through hole
37 humps
40 ribs
41 depression
42 Engagement ring
43 depression
44 Flange
45 Channel (channel)
46 Protrusions
48 Hub

Claims (8)

An assembly having a first needle and a second needle insertable into the first needle, the first needle having a hub provided with a rearward projecting member projecting rearward at a rear end portion; The second needle has a hub provided with a forward projecting member projecting forward at a rear end portion, and one of these members can be inserted into the other member, and the outer surface of the one member and In the needle assembly provided with the grip forming portion that engages and cooperates with the inner surface of the other member, an elastic member (33) is provided in one of the grip forming portions, and the other grip forming portion has the other The first and second elongated regions (20, 21) parallel to each other along the member (16) corresponding to the grip forming portion are provided, and the first elongated region (20) is provided as the elastic member (33). ) And the elastic member (33 Is configured to slide fit along the length of the first elongated region (20), and when the two members (16, 32) are twisted together in the second elongated region (21), the elasticity The member (33) slides in the lateral direction, but the elastic member is prevented from moving in the longitudinal direction along the second elongated region (21), and the relative movement of the two members in the longitudinal direction is prevented. A needle assembly having a surface forming portion (22) for locking the needle. The needle assembly according to claim 1, wherein the surface forming portion is provided in the second elongated region (21) by a series of ribs (22) extending laterally parallel to each other. The needle assembly according to claim 2, wherein the series of ribs (22) comprises long ribs and short ribs arranged alternately. The needle assembly according to any one of claims 1 to 3, wherein the rear projecting member (16) is insertable into the front projecting member (32). 5. The locking device according to claim 1, wherein the two needles (1, 2) are locked to relative movement in the longitudinal direction, and then the two needles (1, 2) are relatively rotatable within a limited range. The needle assembly according to any one of claims. 6. The rear projecting member is constituted by a cylindrical sleeve (16), and the sleeve (16) is rotatable within a restricted range with respect to the hub (11) of the first needle (1). The needle assembly according to any one of the above. The needle assembly according to any one of claims 1 to 6, wherein the elastic member (33) is shorter than the second elongated region (21). The needle assembly according to any one of claims 1 to 7, wherein the elastic member (33) is provided on an inner surface of the other member (32).

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