HK1117774A1 - Catheter and introducer needle assembly with safety device - Google Patents

Abstract

Abstract The present invention relates to a safety device for catheter and introducer needle assembly, said safety device including: a spring clip (50) having at 5 least one first catch (52), at least one second catch (55) and a tab (53); the first catch (52) of the spring clip (50) is irreversibly engaged the first latch (47) of the needle shield (40), and the tab (53) moves in front of the distal end of the introducer needle, and the restriction means (80) restricts the distal end of the introducer needle (31) from moving out of the needle io shield (40) after the withdrawal of the introducer needle (31) . The safety device of the present invention could prevent reuse of the spring clip or needle shield or the assembly. H:\jacindat\keep\9peci\P61896doc 23/08/06 '.0 00 en0 CQ --Lw en~

Description

Catheter and introducer needle assembly with safety device

Technical Field

The present invention relates to a catheter and introducer needle assembly and, more particularly, to a safety device for a catheter and introducer needle assembly.

Background

Intravascular catheters, particularly intravenous catheters (IV catheters), are commonly used for infusing a patient with a fluid, such as saline solution in general, various medicaments, and injections of nutrients, etc., or for withdrawing blood from a patient. Peripheral venous catheters are typically relatively short, on the order of two inches or less in size. The most common type of catheter is a peripheral venous catheter fitted over an introducer needle. The peripheral venous catheter fitted over the introducer needle is fitted over an introducer needle having a sharp needle tip. The catheter and the introducer needle are assembled with the tip of the introducer needle extending beyond the tip of the catheter and with the tip of the introducer needle facing upwardly.

The catheter and introducer needle assembly are inserted at a shallow angle through the patient's skin into the peripheral vessel which is not directly connected to the heart, but rather is connected to one of the central vessel branches which are directly connected to the heart. In one technique, the introducer needle and catheter are inserted together completely into the blood vessel. In yet another technique, the introducer needle is partially withdrawn from the catheter after the initial venipuncture. The catheter is then fully inserted into the blood vessel.

After insertion of the catheter and introducer needle assembly into the blood vessel, it is important to confirm that the assembly is in the correct position in the blood vessel. To confirm that the assembly is properly positioned, the medical personnel need to confirm that flashback blood is present in the introducer needle and in a flashback chamber located at the proximal end of the introducer needle. Typically the flashback chamber forms part of the catheter hub. Alternatively, the introduction needle may be provided with a recess or opening in its distal part, so that, when the catheter is made of a transparent or translucent material, a backflow of blood can be observed in the annular space between the introduction needle and the catheter. Once proper positioning is confirmed, the medical professional will apply pressure to the blood vessel by depressing the patient's skin at the tip of the introducer needle and catheter assembly. The pressure of the finger will occlude further blood flow through the introducer needle. Occlusion of blood flow may also be achieved by an isolation plug. The medical professional withdraws the introducer needle leaving the catheter in place and then attaches a fluid delivery device such as a conventional heparin cap or a head cap to the catheter. Once the introducer needle is withdrawn from the catheter, it will carry a "blood-contaminated needle tip" which must be properly disposed of.

In recent years, there has been considerable interest in the blood that medical personnel may be contaminated with, and it has been recognized that the "blood-contaminated needle tip" must be disposed of immediately. This concern is growing because of the advent of currently untreatable fatal diseases, such as acquired immunodeficiency syndrome (AIDS), which may be transmitted from one infected person to another by the exchange of bodily fluids. Therefore, contact with the body fluids of aids infected persons must be avoided. As described above, if an introducer needle has been used to place a catheter into the vasculature of an AIDS infected person, the introducer needle is a vehicle for the delivery of the disease. Although medical personnel are already aware of the need to properly handle "blood-contaminated needle tips", unfortunately in certain medical environments, such as emergency situations or due to lack of attention or negligence, there is still a situation where contaminated introduction needles stick to medical personnel.

To address the above-mentioned problem of accidental sticks by "blood-contaminated needle tips", various introducer needle safety devices have been developed.

US6287278 discloses an IV catheter assembly provided with a spring clip for protecting a user. However, the IV catheter assembly is not provided with a housing or a housing surrounding the spring clip. Although the spring clip prevents the user from contacting the tip of the introducer needle, it does not prevent the user from contacting residual blood on the tip, particularly if the introducer needle is provided with circumferential holes such as flashback notches. Therefore, the IV catheter assembly of US6287278 remains unsafe for the user.

US5215528 discloses a catheter and introducer needle assembly having a metal clip therein which prevents a user from being injured by an introducer needle after the catheter is inserted into a blood vessel and the introducer needle is withdrawn from the catheter. As shown in the drawings of US5215528, the catheter and introducer needle assembly has a plurality of arcuate projections 50 extending from the flange 48 that define a receiving seat 53 in which the catheter hub 52 is retained 53. One end of the tube 38 defines a boss 38a extending into the catheter hub. The end of the arcuate projection 50 includes inwardly extending lips 54 that releasably retain a catheter hub flange 56. The arcuate projection 50 and lip 54 are designed to engage the flange 56 and make it easier for a user to withdraw the needle shield from the introducer needle hub by means of the projection 48b than to remove the catheter hub 52 from the receiving hub 53. However, the above-described fitting relationship is not reliable because it depends on manufacturing tolerances. Thus, the disengagement between the catheter hub and the introducer needle shield is unpredictable and may occur before the needle tip is safely shielded. This unstable behavior is not suitable in some environments where accuracy and reliability are required.

US6749588 discloses a catheter and introducer needle assembly with a needle shield. A spring clip is disposed in the needle shield. After the introduction needle is withdrawn, the needle shield with the spring clip will grip over the needle tip of the introduction needle, preventing the user from touching the blood on the needle tip. However, such needle shields do not prevent reuse after use, i.e. after extraction of the introducer needle, the spring clip can be removed from the needle shield without damaging the needle shield or the spring clip, and the introducer needle can then be reinserted into the catheter for reuse.

Accordingly, there remains a need in the art for improved safety devices for catheters and introducer needle assemblies that overcome the above-described disadvantages.

Disclosure of Invention

It is an object of the present invention to provide a safety device for a catheter and introducer needle assembly which not only prevents the user from contacting the needle tip after insertion of the catheter into a blood vessel and withdrawal of the introducer needle from the catheter but also prevents the user from contacting the residue on the needle tip.

The present invention also provides a safety device for a catheter and introducer needle assembly that prevents the needle shield, the introducer needle, or the entire assembly from being reused after the introducer needle has been withdrawn, i.e., the user cannot reset the spring clip from pulling out the needle back to the original compression mode after the introducer needle has been withdrawn.

The above object of the present invention is achieved by a safety device for a catheter and introducer needle assembly comprising:

a catheter assembly having: a catheter having a distal end and a proximal end; and a catheter hub in fluid communication with the catheter, the catheter hub having a proximal end and a distal end, the distal end of the catheter hub being connected to the proximal end of the catheter;

an introducer needle assembly having: an introducer needle having a proximal end, a distal end, and a longitudinal axis; an introducer needle hub secured to the proximal end of the introducer needle, the introducer needle being mounted in the catheter;

the safety device includes: a needle shield defining a longitudinally extending channel and being provided with an opening in a direction transverse to the longitudinal direction of the longitudinally extending channel, the longitudinally extending channel having a diameter at least slightly larger than the diameter of the introducer needle so that the introducer needle can pass through the longitudinally extending channel, at least one first and one second snap-in parts being formed on the needle shield; a spring clip provided with at least one first catch, at least one second catch and a blocking tab, said spring clip being mounted into the needle shield through said opening, the second catch of the spring clip being irreversibly engaged with the second caught portion of the needle shield, said spring clip being adapted to telescope in a plane substantially perpendicular to the longitudinal axis of the introducer needle between a compressed mode before withdrawal of the introducer needle and an expanded mode after withdrawal of the introducer needle; and a limiting device used for limiting the far end of the introducing needle to move out of the needle shield after the introducing needle is extracted,

wherein, before the introduction needle is extracted, the spring clip is abutted against the compression mode by the introduction needle passing through the extension channel, and the second clamping part of the spring clip is irreversibly engaged with the second clamped part. And when the introducing needle is drawn out and moves through the spring clip, the spring clip is released by the introducing needle to be bounced to the opening mode, after the introducing needle is drawn out, the first clamping part of the spring clip irreversibly engages with the first clamped part of the needle shield, and the blocking piece moves to the front of the distal end of the introducing needle to prevent the distal end of the introducing needle from moving to the outside of the needle shield in the distal direction. The engagement between the first snap-fit portion and the first engaged portion prevents the spring clip from being recompressed after the introduction needle is withdrawn, while the engagement between the second snap-fit portion and the second engaged portion prevents the spring clip from being pulled out of the needle shield before and after the introduction needle is withdrawn, and the limiting device limits the distal end of the introduction needle from moving out of the needle shield in the proximal direction after the introduction needle is withdrawn.

The present invention also provides a catheter and introducer needle assembly comprising:

a catheter assembly having: a catheter having a distal end and a proximal end; and a catheter hub in fluid communication with the catheter, the catheter hub having a proximal end and a distal end, the distal end of the catheter hub being connected to the proximal end of the catheter;

an introducer needle assembly having: an introducer needle having a proximal end, a distal end, and a longitudinal axis; an introducer needle hub secured to the proximal end of the introducer needle, the introducer needle being mounted in the catheter;

a security device, comprising: a needle shield defining a longitudinally extending channel and being provided with an opening in a direction transverse to the longitudinal direction of the longitudinally extending channel, the longitudinally extending channel having a diameter at least slightly larger than the diameter of the introducer needle so that the introducer needle can pass through the longitudinally extending channel, at least one first and one second snap-in parts being formed on the needle shield; a spring clip provided with at least one first catch, at least one second catch and a blocking tab, said spring clip being mounted into the needle shield through said opening, the second catch of the spring clip being irreversibly engaged with the second caught portion of the needle shield, said spring clip being adapted to telescope in a plane substantially perpendicular to the longitudinal axis of the introducer needle between a compressed mode before withdrawal of the introducer needle and an expanded mode after withdrawal of the introducer needle; the limiting device is used for limiting the far end of the introducing needle to move out of the needle shield after the introducing needle is extracted;

wherein, before the introduction needle is extracted, the spring clip is abutted against the compression mode by the introduction needle passing through the extension channel, and the second clamping part of the spring clip is irreversibly engaged with the second clamped part. And when the introducing needle is drawn out and moves through the spring clip, the spring clip is released by the introducing needle to be bounced to the opening mode, after the introducing needle is drawn out, the first clamping part of the spring clip irreversibly engages with the first clamped part of the needle shield, and the blocking piece moves to the front of the distal end of the introducing needle to prevent the distal end of the introducing needle from moving to the outside of the needle shield in the distal direction. The engagement between the first snap-fit portion and the first engaged portion prevents the spring clip from being recompressed after the introduction needle is withdrawn, while the engagement between the second snap-fit portion and the second engaged portion prevents the spring clip from being pulled out of the needle shield before and after the introduction needle is withdrawn, and the limiting device limits the distal end of the introduction needle from moving out of the needle shield in the proximal direction after the introduction needle is withdrawn.

The above and other advantages of the present invention will be understood by reading the following description with reference to the accompanying drawings, in which preferred embodiments of the invention are shown.

Description of the drawings

The invention will be described hereinafter with reference to preferred embodiments shown in the drawings.

Wherein:

FIG. 1 shows the entire product of a catheter and introducer needle assembly with the safety device of the present invention;

FIG. 2 shows an exploded view of the catheter and introducer needle assembly shown in FIG. 1;

FIG. 3 shows an enlarged view of a spring clip in a first embodiment of the invention;

FIG. 4 shows a partial view of the catheter and the introduction needle assembly of the first embodiment, showing a state before activation of the spring clip, in which the spring clip is folded in its compression mode and is held in the compression mode by the introduction needle;

FIG. 5 shows another partial view of the catheter and introducer needle assembly of the first embodiment, also shown prior to the spring clip being activated;

FIG. 6 is a perspective view showing the position of the first catch of the spring clip located in the needle shield prior to activation of the spring clip;

figure 7 shows a further view of the safety device in the first embodiment before the spring clip is activated;

FIG. 8 shows a partial view of the catheter and introducer needle assembly of the first embodiment after activation of the spring clip;

FIG. 9 shows another view of the catheter and introducer needle assembly of the first embodiment after the spring clip has been activated;

FIG. 10 shows another view of the catheter and introducer needle assembly of the first embodiment after the spring clip has been activated;

FIG. 11 is a perspective view showing the position of the first catch of the spring clip in the needle shield after the spring clip has been activated;

FIG. 12 is a sectional view showing the positional relationship of the tip of the introducer needle relative to the stop of the spring clip after activation of the spring clip;

FIG. 13 is a view showing the washer blocking movement of the introducer needle in a rearward direction;

the view of fig. 14 clearly shows that the second catch of the spring clip engages with the second catch located on the needle shield to prevent reuse.

FIG. 15 is an exploded view showing a second embodiment of a safety device incorporating a V-shaped spring clip;

FIG. 16 shows a V-shaped spring clip in a second embodiment;

figure 17 shows the safety device in a second embodiment after the spring clip has been triggered;

fig. 18 shows a gasket used in the second embodiment;

figure 19 shows a third embodiment of the safety device in which a tether is used as a stop.

Detailed Description

As used herein, the terms "proximal" and "distal" are used with respect to the introduction needle hub 34 to describe a location on the catheter and introduction needle assembly 10. The term "forward direction" refers to a direction toward the tip of the introducer needle, while "rearward direction" refers to a direction away from the tip.

In the present invention, the same reference numerals are used to identify the same parts or components in different embodiments. In addition, while the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described in detail a preferred embodiment of the invention, with the scope of the invention being defined by the appended claims.

A first embodiment of the invention is shown in fig. 1-14.

As shown in fig. 1 and 2, the catheter and introducer needle assembly with the safety device of the first embodiment of the present invention is generally designated by the reference numeral 10. It comprises a catheter assembly 20, an introducer needle assembly 30 and a safety device.

Catheter assembly 20 includes a catheter 21, the catheter 21 having a proximal end, a distal end, and a catheter hub 24 secured to the proximal end of the catheter 21. Suitable materials for catheter 21 include, but are not limited to, thermoplastic resins such as Polytetrafluoroethylene (PTFE), polyurethane, and the like. Preferably, the catheter 21 is made of a transparent or at least translucent material in order to observe reflux when the introduction needle 31 is provided with an optional reflux groove 35. Suitable materials for catheter hub 24 include, but are not limited to, thermoplastic polymer resins such as polycarbonate, polystyrene, polypropylene, and the like.

The introduction needle assembly 30 comprises an introduction needle 31, which introduction needle 31 has a sharp distal needle tip 32 formed by a bevel and a proximal end connected to an introduction needle hub 34. Near the sharp distal tip 32, the introducer needle 31 includes an abrupt site 33, for example, in this embodiment, the abrupt site 33 may be an abrupt site of increased diameter. The introduction needle 31 is preferably made of stainless steel. Optionally, a flashback notch 35 can be provided on introducer needle 31 to permit visualization of blood flashback in the annular space between the outer surface of introducer needle 31 and the lumen of catheter 21. In a further alternative, the flashback recess 35 may be absent, and an integral flashback chamber may be provided in the introducer needle hub 34. Introducer needle hub 34 is preferably made of the same material as catheter hub 24. Preferably, a gripping tab 36 may extend from the introducer needle hub 34 for gripping. When assembled together, catheter 21 is sleeved over introducer needle 31.

The safety device comprises a needle shield 40, which needle shield 40 is preferably made of plastic. The safety device also includes a spring clip 50 mounted in needle shield 40, as shown in fig. 2, 4, and 5. As shown in Figs. 8-10, once catheter 21 is inserted into a blood vessel and introducer needle 31 is withdrawn from the catheter, needle shield 40 and spring clip 50 will grip over the tip of the introducer needle, thereby preventing the user from being pricked by the tip. Needle shield 40 defines a longitudinally extending channel 42. Longitudinally extending passage 42 can permit introduction needle 31 to pass longitudinally through needle shield 40. The diameter of the extension channel 42 is at least slightly larger than the diameter of the shaft of the introduction needle 31. This allows the shaft of the introduction needle 31 to easily pass through the extension passage 42. Extension channel 42 includes a distal portion 44 and a proximal portion 45, distal portion 44 surrounding the proximal end of catheter hub 20 prior to withdrawal of introducer needle 31, and proximal portion 45 enclosing the distal portion of introducer needle 31 after withdrawal of introducer needle 31. The safety device further comprises a limiting means 80 which will limit the movement of the needle tip of the introduction needle out of needle shield 40 after extraction of introduction needle 31.

As shown in fig. 4 and 5, an opening 60 is provided in needle shield 40 in the direction along its longitudinal axis. The opening 60 communicates with the extension passage 42. Spring clip 50 is mounted in needle shield 40 through opening 60. Prior to the extraction of the introduction needle 31, the spring clip 50 will fold into its compression mode and be abutted by the introduction needle 31 in its compression mode, in which case the spring clip 50 will be located to one side of the axis of the introduction needle 31 (see fig. 4, 5 and 7). After withdrawal of introducer needle 31, introducer needle 31 releases spring clip 50 such that spring clip 50 returns from its compressed mode to its expanded mode (see FIGS. 8-10). When the tip of the introduction needle 31 moves past the spring clip 50 during extraction of the introduction needle 31, it will trigger the movement of the spring clip 50 from the compressed mode to the open mode (which will be referred to as "triggering of the spring clip" hereinafter).

The spring clip 50 of the present invention has formed thereon at least one first catching portion 52, at least one second catching portion 55, at least one third catching portion 51 and a stopper 53. The first and second catches 52, 55 are adapted to lock first and second caught portions 47, 47 (not shown) provided on the needle shield 40, thereby preventing reuse after the spring clip is triggered. Third snap-fit portion 51 is adapted to engage a snap-fit portion 25 formed on catheter hub 24 when spring clip 50 is in a pre-activation compression mode. The stop 53 is provided to stop the introduction needle from moving in the distal direction after the spring clip is activated. These are described in further detail below.

In fig. 3, a spring clip 50 according to a first embodiment of the invention is shown, although the spring clip 50 may have other shapes, but it may preferably be a V-shaped spring clip according to the first embodiment. Spring clip 50 is mounted in needle shield 40 through opening 60 with the apex of the V pointing in the opposite direction to opening 60, and the two legs forming the V will ride on the longitudinal axis of introducer needle 31 when spring clip 50 is in its open mode. In this orientation, spring clip 50 is adapted to move transversely to the longitudinal axis of introducer needle 31 when the spring clip is activated. This movement may be along a path defined by a ramp surface on needle shield 40. Of course, spring clip 50 may be arranged in needle shield 40 with the apex of its V-shape at other locations in a circle coaxial with the longitudinal axis of introducer needle 31. All that is necessary is that spring clip 50 is adapted to move transversely to the longitudinal axis of introducer needle 31. The apex of the V facilitates its compression toward or expansion from compression mode. Alternatively, the apex of the V-shape may be in the form of a living hinge.

In the first embodiment, the spring clip 50 defines a V-shape on one of the two legs provided with a clip arm 54 extending substantially parallel to the longitudinal axis of the introduction needle 31. Two fingers are formed on both longitudinal ends of the holding arm 54. Preferably, the two fingers extend substantially perpendicular to the longitudinal axis of the introduction needle 31. The first catching portion 52 is formed on one of the fingers, and the third catching portion 51 is formed on the other finger. In this first embodiment, first catch 52 may be at least one non-return catch or barb projecting from the finger toward needle shield 40. While first captured portion 47 formed on needle shield 40 may be an anti-backup tooth or recess, as better shown in fig. 14.

At the free end of the other leg of the spring clip 50, which defines the V-shape, a finger 56 is formed by folding the free end towards the outside of the V-shape. A second click portion 55 is formed on the finger 56. As shown in fig. 3, the second catching portion 55 may be at least one non-return catching tooth or barb. When the spring clip 50 is installed in the needle shield 40, the finger 56 will be inserted into the groove 49 (see fig. 7) formed on the needle shield 40, and the non-return latch or barb as the second latch 55 will engage with a second latched part such as a non-return latch or recess (not shown) formed on the inner wall of the groove 49, so that the finger 56 of the spring clip 50 cannot be pulled out once inserted into the groove 49. Alternatively, the second snap-in portion 55 may have other configurations, such as a flange formed by bending the free end of the finger 56. It is necessary that second snap 55 and second snap-in (not shown) should prevent spring clip 50 from being pulled out of needle shield 40 after they are engaged.

Due to the action of the first and second catches 52, 55, after activation of the spring clip, the user cannot return the spring clip to the pre-activation state without destroying the spring clip or the needle shield, thereby preventing reuse of the spring clip or the introducer needle or the entire catheter and introducer needle assembly.

As described above, in the first embodiment, the third catching portion 51 is a finger formed on the grip arm 54 extending substantially parallel to the longitudinal axis of the introducing needle 31. Third captured portion 25 may be a flange, threads, grooves, non-return latch, etc. formed on catheter hub 24. Although the use of third snap-in part 51 and third snap-in part 25 is preferred because it provides an active mechanical connection between needle shield 40 and catheter hub 24, third snap-in part 51 and third snap-in part 25 are not required. If they are not present, friction between needle shield 40 and catheter hub 24 can be used as the engagement force, which is easier to overcome than the positive mechanical engagement forces described above. However, in some cases, such friction is sufficient.

The flap 53 is provided to prevent the introduction needle from moving in a forward direction after the spring clip is triggered. This will be described in detail below. Although the flap 53 is preferably free of a hole, the flap 53 may alternatively be provided with a hole having an inner diameter larger than the diameter of the shaft of the introduction needle 31 but smaller than the enlarged portion 33 of the introduction needle 31. In this way, after the spring clip has been triggered, the tip of the introduction needle can be inserted into the hole, but the enlarged portion of the introduction needle 31 is caught by the hole.

Fig. 4 shows the catheter and introducer needle assembly prior to activation of spring clip 50. In this state, spring clip 50 is folded in its compressed mode and installed in extended channel 42 of needle shield 40 through opening 60. The spring clip 50 is held in this compression mode against which the introduction needle 31 abuts. The distal end of catheter hub 24 is circumferentially surrounded by distal portion 44 of extended channel 42 of needle shield 40.

Fig. 5 shows another view of the spring-actuated state of the spring clip 50. The spring clip 50 is held in the compression mode by the introducer needle 31. The third engagement portion 51 engages with the third engaged portion 25, and the third engaged portion 25 may be, for example, a flange on the catheter hub 24. Fig. 6 more clearly shows the position of the third catching portion 51 before the spring clip is activated. In this state, third snap-fit portion 51 extends into distal portion 44 of extension channel 42 and engages third snap-fit portion 25 on the proximal end of catheter hub 24, thus positively preventing removal of needle shield 40 from catheter hub 24.

Figure 7 shows another view of the spring clip in a pre-activated state. Spring clip 50 is held in the compression mode by introducer needle 31. Third snap-in portion 51 extends into distal portion 44 circumferentially surrounding catheter hub 24.

Figures 8, 9, and 10 illustrate the spring clip 50 after activation. Once catheter 21 is inserted into the blood vessel, the medical professional will withdraw introducer needle 31 from catheter 21. With the withdrawal movement of introduction needle 31 from catheter 21, spring clip 50 in the compressed mode will be released by introduction needle 31 after the tip of introduction needle 31 moves past spring clip 50, whereby spring clip 50 springs open from its compressed mode to its expanded mode. When spring clip 50 is expanded, third snap-fit portion 51 will no longer extend into distal portion 44 of elongate channel 42, thereby disengaging third snap-fit portion 25 located on catheter hub 24. In this case, needle shield 40 is free to move in a rearward direction along the axis of introducer needle 31. Due to the opening action of the spring clip 50, the flap 53 of the spring clip 50 will move from a position not closing the aperture 46 on the proximal portion of the extension channel 42 to a position closing the aperture 46, and the introduction needle 31 will be retracted into this proximal portion of the extension channel (see fig. 8, 10 and 12). In this way, flap 53 will prevent introduction needle 31 from moving forward to re-enter catheter 21. At the same time, stop 80 will limit the removal of introducer needle 31 out of needle shield 40 after the spring clip is activated. In this embodiment, the stop means 80 may be a washer having a hole sized to be slightly larger in diameter than the enlarged diameter discontinuity 33 of the introducer needle 31 at the shank portion of the introducer needle 31. The washer may be mounted in a recess in the proximal portion of needle shield 40, with introducer needle 31 passing through the bore of the washer. The washer 80 will block the enlarged diameter portion 33 of the introducer needle 31. Thus, the distal portion of the introduction needle 31 will be enclosed from view in the proximal portion 45 of the extension channel 42. Thus, residual blood on the needle tip will be enclosed within the proximal portion 45 of the elongate channel 42.

The washer 80 may be a circular washer (see fig. 2) or may be other shapes (as shown in fig. 18). The only requirement is that the bore of the washer 80 is slightly larger than the diameter of the shaft of the introducer needle 31 but smaller than the enlarged diameter of the abrupt change 33.

After spring clip activation, a first catch 52 (not visible to the user) on spring clip 50 engages a first caught 47 on needle shield 40 to prevent spring clip 50 from being recompressed, thereby preventing reuse. The spring clip 50 will be prevented from being reset back to the pre-trigger state by the engagement of the first caught portion 47 and the first catching portion 52, thereby preventing reuse.

As shown in fig. 10, 12 and 13, a washer 80, which in this embodiment acts as a stop, is disposed in the elongate channel 42 of needle shield 40. The aperture of washer 80 is sized to allow a uniform shank portion of introducer needle 31 to pass through but to block the enlarged diameter abrupt portion 33 of introducer needle 31. Thus, the aperture of washer 80 will block enlarged diameter portion 33 of introducer needle 31 and prevent further withdrawal of introducer needle 31.

The abrupt change 33 of increased diameter may be, for example, a protrusion positioned such that the blood backflow groove 35 (if any) on the introduction needle 31 and the tip of the introduction needle are enclosed within the proximal portion 45 of the extension passage 42 when the abrupt change is stopped by the gasket 80. In addition, the protrusion is located in front of the groove 35, so that the protrusion 33 does not have a reduction effect on the backflow when the backflow of blood occurs. The projection may be a separate iron ring which is mounted on the introduction needle 31, however, the projection is preferably formed by pressing two opposite points of the corresponding area of the introduction needle 31, the pressed area being flattened to form a distinct projection in a direction perpendicular to the pressing. Such a protrusion may be referred to as a "crush protrusion".

As shown in FIG. 8, with further withdrawal of introducer needle 31, introducer needle assembly 30 and needle shield 40 will disengage from catheter hub 24 because third catch 51 of spring clip 50 now disengages from third catch 25 of catheter 24 and the projection of introducer needle 31 is blocked by washer 80.

Of course, the first snap-in portion 52 may have other configurations than the first embodiment, for example, fig. 15-18 illustrate a second embodiment of the security device of the present invention in which the first snap-in portion 52 of the spring clip 50 is a non-return snap tooth formed by folding the edge of a finger. Therefore, it is necessary that the first catching portion 52 and the first caught portion 47 should be formed such that their engagement prevents the spring clip 50 from being recompressed by the user after activation. In addition, washer 80 need not be circular, but may be other shapes (see FIG. 18), all that is required is that the diameter of the bore of washer 80 should be larger than the diameter of the shaft of introducer needle 31 but smaller than the enlarged diameter discontinuity 33 of introducer needle 31.

A third embodiment of the security device of the present invention is shown in figure 19. In this embodiment, the stop 80 is not a washer but a tether, which may be made of plastic. Prior to withdrawal of introduction needle 31, tether 80 is folded between introduction needle hub 34 and needle shield 40 with one end connected to introduction needle hub 34 and the other end connected to needle shield 40. The length of tether 80 will limit the movement of the tip of introducer needle 31 out of needle shield 40 after introducer needle 31 is withdrawn. Fig. 19 shows a state after the introduction needle 31 is withdrawn. In the third embodiment, since the tether 80 is used, the abrupt change portion 33 on the introducing needle 31 is not required.

It is worth mentioning that the washer 80 and the enlarged stepped portion 33 are used in the first and second embodiments, but other configurations may be adopted. For example, the limiting means may be a separate leaf spring, and the abrupt change 33 is not an enlarged part but a groove on the introducing needle 31. When the groove of the introduction needle 31 moves through the separate spring plate when the introduction needle 31 is withdrawn, the spring plate will catch in the groove. Alternatively, stop 80 may simply be a hole in elongate channel 42 of needle shield 40 having an inner diameter that is smaller than enlarged break 33 of introducer needle 31 and smaller than the diameter of the shaft of the introducer needle.

After extraction of introduction needle 31, needle shield 40 will grip on the distal portion of introduction needle 31 because a stop 80, such as a washer, tether, or separate spring tab, will reliably prevent the distal portion of introduction needle 31 from moving out of needle shield 40, even if introduction needle 31 is rotated relative to the needle shield.

In the foregoing, the present invention has been described by way of examples, but these examples should not be construed as limiting the present invention, and it is understood that variations may be made in the examples by those skilled in the art. The scope of protection of the invention is defined by the appended claims.

Claims (26)

1. A safety device for a catheter and introducer needle assembly (10), said catheter and introducer needle assembly (10) comprising:

a catheter assembly (20) has: a catheter (21) having a distal end and a proximal end; and a catheter hub (24) in fluid communication with the catheter (21), the catheter hub having a proximal end and a distal end, the distal end of the catheter hub being connected to the proximal end of the catheter (21);

an introduction needle assembly (30) having: an introducer needle (31) having a proximal end, a distal end, and a longitudinal axis; an introducing needle holder (34) fixed to a proximal end of an introducing needle (31), the introducing needle (31) being housed in a catheter (21);

the safety device includes: a needle shield (40), the needle shield (40) defining a longitudinally extending channel (42), and being provided with an opening (60) in a direction transverse to the longitudinal direction of the longitudinally extending channel (42), the diameter of the longitudinally extending channel (42) being at least slightly larger than the diameter of the introducing needle (31) so that the introducing needle (31) can pass through the longitudinally extending channel (42), at least one first and at least one second snap-in parts (47, 47) being formed on the needle shield (40); a spring clip (50) provided with at least one first catch (52), at least one second catch (55) and a catch (53), said spring clip (50) being mounted into the needle shield (40) through said opening (60), the second catch (55) of the spring clip (50) being irreversibly engaged with the second catch of the needle shield (40), said spring clip (50) being adapted to telescope in a plane substantially perpendicular to the longitudinal axis of the introducer needle between a compression mode before the introducer needle (31) is withdrawn and an expansion mode after the introducer needle (31) is withdrawn; and a limiting device (80) used for limiting the far end of the introducing needle (31) to move out of the needle shield (40) after the introducing needle (31) is extracted,

wherein the spring clip (50) is urged against the compression mode by the introducer needle (31) passing through the elongate channel (42) prior to withdrawal of the introducer needle (31), and is released by the introducer needle to spring open to the open mode when the introducer needle (31) is moved past the spring clip (50) as the introducer needle is withdrawn, and wherein after withdrawal of the introducer needle, a first catch (52) of the spring clip irreversibly engages a first catch (47) of the needle shield (40), the catch (53) moves forward of the distal end of the introducer needle to prevent the introducer needle from moving back, wherein engagement between the first catch (52) and the first catch (47) prevents recompression of the spring clip (50) after withdrawal of the introducer needle (31), and engagement between the second catch (55) and the second catch prevents the spring clip (50) from being withdrawn from the needle shield (40), a limiting device (80) limits the movement of the distal end of the introducing needle (31) out of the needle shield (40) after the introducing needle (31) is extracted.

2. The safety device for a catheter and introducer needle assembly (10) according to claim 1, wherein the spring clip (50) is further provided with at least one third catch (51), the third catch (51) positively engaging a third catch (25) formed on the catheter hub (24) when the spring clip (50) is in a compression mode before the introducer needle (31) is withdrawn, and the third catch (51) disengaging the third catch (25) when the spring clip (50) is in an open mode after the introducer needle is withdrawn.

3. The safety device for a catheter and introducer needle assembly (10) according to claim 1 or 2, wherein the spring clip (50) is a V-shaped spring clip with the apex of the V facing opposite the opening (60), the two legs defining the V riding on the longitudinal axis of the introducer needle (31) when the spring clip (50) is in the open mode.

4. The safety device for a catheter and introducer needle assembly (10) as set forth in claim 3, wherein one of the two legs of the spring clip (50) defining the V-shape is provided with a retaining arm (54) substantially parallel to the longitudinal axis of the introducer needle (31), a finger is formed at each end of the retaining arm (54), the first catch (52) is a non-return catch tooth formed on one of the fingers, and the first catch (47) is a non-return catch tooth or recess formed on the needle shield (40).

5. The safety device for a catheter and introducer needle assembly (10) as set forth in claim 4, wherein said first snap (52) is a barb formed on one of said fingers.

6. The safety device for a catheter and introducer needle assembly (10) as set forth in claim 4, wherein said first snap (52) is a flange formed by folding an edge of one of said fingers.

7. Safety device for a catheter and introducer needle assembly (10) according to claim 3, wherein said second snap (55) is a non-return snap tooth formed on the other leg defining a V-shape.

8. The safety device for a catheter and introducer needle assembly (10) as set forth in claim 7, wherein said second snap (55) is a non-return snap tooth formed on a finger (56) defining the free end of the other leg forming a V-shape.

9. The safety device for catheter and introducer needle assembly (10) of claim 1 wherein said stop means (80) is a washer mounted on the needle shield (40) having a hole with a diameter larger than the diameter of the shaft of the introducer needle (31) and smaller than an enlarged diameter portion (33) on the introducer needle (31) which will block said enlarged diameter portion (33) upon withdrawal of the introducer needle.

10. The safety device for a catheter and introducer needle assembly (10) as set forth in claim 9, wherein the flap (53) includes an aperture having a diameter larger than the shaft of the introducer needle (31) and smaller than the enlarged diameter portion (33) of the introducer needle.

11. The safety device for a catheter and introducer needle assembly (10) as set forth in claim 1, wherein said stop means (80) is a hole in the extended channel of the needle shield (40) having a diameter larger than the shaft of the introducer needle and smaller than the enlarged diameter portion of the introducer needle.

12. The safety device for a catheter and introducer needle assembly (10) as set forth in claim 1, wherein said retention device (80) is a tether connected at one end to said needle hub (34) and at an opposite end to said needle shield (40).

13. The safety device for a catheter and introducer needle assembly (10) as set forth in claim 1, wherein the limiting means (80) is a separate spring tab that will engage an annular recessed portion on the introducer needle (31) after withdrawal of the introducer needle (31).

14. A catheter and introducer needle assembly (10), said catheter and introducer needle assembly (10) comprising:

a catheter assembly (20) has: a catheter (21) having a distal end and a proximal end; and a catheter hub (24) in fluid communication with the catheter (21), the catheter hub having a proximal end and a distal end, the distal end of the catheter hub being connected to the proximal end of the catheter (21);

an introduction needle assembly (30) having: an introducer needle (31) having a proximal end, a distal end, and a longitudinal axis; an introducing needle holder (34) fixed to a proximal end of an introducing needle (31), the introducing needle (31) being housed in a catheter (21);

a security device, comprising: a needle shield (40), the needle shield (40) defining a longitudinally extending channel (42), and being provided with an opening (60) in a direction transverse to the longitudinal direction of the longitudinally extending channel (42), the diameter of the longitudinally extending channel (42) being at least slightly larger than the diameter of the introducing needle (31) so that the introducing needle (31) can pass through the longitudinally extending channel (42), at least one first and at least one second snap-in parts (47, 47) being formed on the needle shield (40); a spring clip (50) provided with at least one first catch (52), at least one second catch (55) and a catch (53), said spring clip (50) being mounted into the needle shield (40) through said opening (60), the second catch (55) of the spring clip (50) being irreversibly engaged with the second catch of the needle shield (40), said spring clip (50) being adapted to telescope in a plane substantially perpendicular to the longitudinal axis of the introducer needle between a compression mode before the introducer needle (31) is withdrawn and an expansion mode after the introducer needle (31) is withdrawn; and a limiting device (80) for limiting the movement of the distal end of the introducing needle (31) out of the needle shield (40) after the introducing needle (31) is extracted;

wherein the spring clip (50) is abutted against the compression mode by the introduction needle (31) passing through the extension passage (42) before the introduction needle (31) is withdrawn, and is released by the introduction needle to spring open to the open mode when the introduction needle is withdrawn and the introduction needle (31) moves through the spring clip (50), and after the introduction needle is withdrawn, a first catch (52) of the spring clip irreversibly engages a first catch (47) of the needle shield (40), the blocking piece (53) moves in front of the distal end of the introduction needle to prevent the introduction needle from moving back, and engagement between the first catch (52) and the first catch (47) prevents the spring clip (50) from being recompressed after the introduction needle (31) is withdrawn, and engagement between the second needle shield (55) and the second catch prevents the spring clip (50) from being withdrawn from the needle shield (40), and a limiting means (80) limits the distal end of the introduction needle (31) from moving out of the needle shield (31) after the introduction needle (31) is withdrawn (40) And (c) out.

15. The catheter and introducer needle assembly (10) of claim 14, wherein the spring clip (50) is further provided with at least one third snap-fit portion (51), the third snap-fit portion (51) positively engaging a third snap-fit portion (25) formed on the catheter hub (24) when the spring clip (50) is in a compression mode prior to introducer needle (31) withdrawal, and the third snap-fit portion (51) disengaging the third snap-fit portion (25) when the spring clip (50) is in an open mode after introducer needle withdrawal.

16. Catheter and introducer needle assembly (10) according to claim 14 or 15, wherein the spring clip (50) is a V-shaped spring clip with the apex of the V facing opposite the opening (60), the two legs defining the V riding on the longitudinal axis of the introducer needle (31) when the spring clip (50) is in the open mode.

17. The catheter and introducer needle assembly (10) of claim 14, wherein one of the two legs of the spring clip (50) defining the V-shape is provided with a retaining arm (54) substantially parallel to the longitudinal axis of the introducer needle (31), a finger being formed at each end of the retaining arm (54), the first catch (52) being a non-return catch formed on one of the fingers, and the first catch (47) being a non-return catch or notch formed on the needle shield (40).

18. The catheter and introducer needle assembly (10) of claim 17, wherein said first snap (52) is a barb formed on one of said fingers.

19. The catheter and introducer needle assembly (10) of claim 17, wherein the first snap (52) is a flange formed by folding an edge of one of the fingers.

20. The catheter and introducer needle assembly (10) of claim 17, wherein the second catch (55) is an anti-backup catch formed on the other leg defining the V-shape.

21. Catheter and introducer needle assembly (10) according to claim 20, wherein said second snap-in portion (55) is a non-return snap tooth formed on a finger (56) defining the free end of the other leg forming a V-shape.

22. The catheter and introducer needle assembly (10) of claim 14, wherein said stop (80) is a washer mounted on the needle shield (40) having a hole with a diameter larger than the diameter of the shaft of the introducer needle (31) and smaller than an enlarged diameter portion (33) on the introducer needle (31) that will block said enlarged diameter portion (33) upon withdrawal of the introducer needle.

23. The catheter and introducer needle assembly (10) of claim 22, wherein the flap (53) includes an aperture having a diameter larger than the shaft of the introducer needle (31) and smaller than the enlarged diameter portion (33) of the introducer needle.

24. The catheter and introducer needle assembly (10) of claim 14, wherein the stop (80) is a hole in the elongate passageway of the needle shield (40) having a diameter larger than the shaft of the introducer needle and smaller than the enlarged diameter portion of the introducer needle.

25. The catheter and introducer needle assembly (10) of claim 14, wherein said retention device (80) is a tether connected at one end to said hub (34) and at the other end to said needle shield (40).

26. Catheter and introducer needle assembly (10) as in claim 14, wherein the limiting means (80) is a separate spring tab which will engage with an annular groove portion on the introducer needle (31) after withdrawal of the introducer needle (31).