J.v. catheter assembly with automatic cannula tip guard.

INTRAVENOUS CATHETER ASSEMBLY WITH AUTOMATIC PROTECTION OF THE

POINT OF THE CANNULA

BACKGROUND OF THE INVENTION

This invention relates to intravenous (IV) catheter assemblies.), In particular, to a catheter assembly that has a cannula tip guard that automatically covers the cannula tip after use to prevent accidental damage with the cannulas used.

Intravenous catheters for infusing fluids into a patient's peripheral veins are one of the most common devices used in IV therapy. In a type of catheter known as an over-the-needle catheter, the cannula and concentric external catheter are inserted into the vein and cannula are withdrawn through the placed catheter.

A typical IV catheter over the needle requires the user to remove and then discard a contaminated cannula after the cannula tip and catheter have been properly placed in the patient's vein. Once the cannula is removed from the catheter, the user's immediate priorities are connection of the infusion set and site preparation, including connection of the catheter to the patient. Due to the urgency of these procedures, the cannula is normally conveniently dropped in the vicinity and then retrieved. Since the cannula is currently exposed and located close to where the user is working with the catheter, accidental damage caused by themselves is common. For the reason of desirably protecting the user from exposure to hepatitis and AIDS, there is a great need to protect the user from accidental damage done with the cannula.

A catheter design that addresses this need is shown in US Patent No. 4,762,516. The catheter shown in this patent includes an elongated body that houses a sliding needle guard. As the needle is withdrawn from the placed catheter, the user pushes the tab on the distal end of the needle shield, thus sliding the needle shield out of the housing and along the needle, until the distal end of the shield Cover the tip of the needle and the near end of the guard locks into the housing. The needle and guard can then be removed with the needle tip fully protected.

Other needle protection is shown in US Patent No. 5,804,023. The needle guard in this patent includes a sleeve that has a locking ring to ensure protection to a return valve assembly. The shield also includes a notch that engages a corresponding depression in the needle to prevent the needle from being removed from the shield.

US Patent No. 4,834,718 also describes a needle tip protection. A hub portion of the protection of this patent mounts within the catheter hub and includes an elastic tongue. The tongue flexes outward to engage a depression in the catheter hub when the needle is inserted through the shield. When the needle is withdrawn into the shield, the tongue flexes inward releasing the shield from the hub. The protection is also made up of a housing that extends over the entire length of the blood chamber. A latch mechanism on the distal end of the housing holds the tip of the needle within the shield.

While the provisions described in the prior art patents provide protection against accidental needle damage, the requirements of each of these devices necessarily require rather long and / or bulky assemblies. Furthermore, the provisions are somewhat cumbersome to operate. by users with small hands and fingers.

Accordingly, it would be desirable for a needle to be securely protected by a small needle guard, and it may be highly preferable for the needle guard to be able to move to a position on the needle tip automatically upon removal of the needle from the patient, without intervention of any special movements made by the user.

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BRIEF DESCRIPTION OF Lfl INVENTION

The present invention is directed to an IV catheter with an automatic cannula guard utilizing a pinch nose design. In accordance with the present invention, a catheter assembly is provided comprising a catheter attached to the catheter hub. A cannula that has a distant tip that is insertable to the catheter through the catheter hub. A tip guard having a base and a plurality of elastic tips extending from the base to provide automatic protection against accidental needle bites after the cannula is removed from the catheter. The plurality of ends are spring loaded such that a distal end of each end is in contact thus forming a closed chamber within the tip guard. The extremities are adapted to flex radially outward to allow the cannula to be inserted into the catheter hub through the tip guard. The limbs return to the spring-loaded contact position when the distal tip of the cannula is withdrawn from the catheter toward the tip shield thus securing the distal tip within the closed chamber. In addition, locking means are provided to couple the tip shield to the catheter hub when the cannula is inserted through the catheter hub. The locking means is adapted to release the tip shield from the catheter hub when the distal tip of the cannula is withdrawn from the catheter toward the tip shield.

In an alternative embodiment, the plurality of ends of the tip guard are spring-driven to form a passageway from the base of the guard to the distal end of each end. The passage is smaller in diameter than the diameter of the catheter. Furthermore, each of the limbs has a channel extending from the base to a site separate from the distant end of the limbs. The channels of the extremities form a chamber that has a diameter substantially equal to the diameter of the cannula. The limbs are adapted to flex radially outward to allow the cannula to be inserted into the catheter through the tip shield. The limbs return to the spring-loaded position when the distal tip of the cannula is withdrawn from the catheter into the tip guard, thus securing the distal tip within the chamber to prevent the distal tip of the cannula from reinserting through from the distant ends of the tips of the tip guard.

The locking means is provided by a detent on the distant ends of the limbs and a corresponding depression in the catheter hub. When the extremities are flexed radially outward to allow the cannula to be inserted into the catheter hub, the retainer on the extremities engages the hub in the depression. The thickness of the cannula makes the limbs remain in that flexed position, thus locking the tip protection on the hub.

The catheter assembly further includes a cannula housing that couples the cannula over the near end of the cannula, a blood expansion chamber attached to the cannula housing, and a cannula guard. The cannula guard is attached to the tip guard and extends radially only over a portion of the cannula. Preferably, the cannula guard extends over less than half the circumference of the cannula, allowing for a low, oblique insertion angle.

brief description, eg DiBuqos

FIG. 1 is a schematic cross-sectional view of the catheter assembly of the present invention.

Figures 2 (a> and 2 (b) are a side elevation view and an end view of a tip protection embodiment of the present invention.

Figure 3 is a side elevation view of the tip guard shown in Figures 2A and 2B with the cannula inserted through the tip guard.

Figure 4 is a side elevation view of a second embodiment of the tip guard of the present invention.

Figures 5, 6 and 7 are side elevation views of the tip guard of Figure 4 showing insertion and removal of a cannula.

Figures 0, 9, 10 and 11 are cross-sectional views taken along the corresponding lines of the tip guard shown in Figure 4.

FIG. 12 is a cross sectional view of one embodiment of the means for locking the tip shield on the catheter hub.

FIG. 13 is a cross sectional view of the catheter hub of the catheter assembly of the present invention.

FIG. 14 is an end view of the catheter housing of the catheter assembly of the present invention.

Figures 15 and 16 are cross-sectional views of the housing taken along the corresponding lines of Figure 14.

Figures 17, 10 and 19 are cross-sectional views of the housing taken along the corresponding lines shown in Figure 16.

Figures 20 (a) and 20 <b) are a side elevation view and an end view of the blood expansion chamber and cannula guard of the catheter assembly of the present invention.

Figures 21, 22 and 23 are schematic views that

-7β show the operation of the catheter assembly of the present invention including insertion into a vein, removal, and protection by tip protection.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, Figure 1 is a schematic side view of the catheter assembly 10 of the present invention. Catheter assembly 10 includes a catheter 12 attached to a catheter hub 14. A cannula 16 having a distant sharp tip 16 can be inserted into catheter 12 through catheter hub 14. Catheter assembly 10 also includes a catheter housing 20 that couples a proximal end 22 of the cannula for insertion and

IS removal of the cannula into and out of catheter 12. A blood expansion chamber 24 is attached to housing 20 and sealed at its open end with a plug 26. Catheter assembly 10 further includes tip guard 26 and a cannula guard 30.

Figures 2 <a), 2 (b) and 3 show detailed views of one embodiment of the tip guard of the present invention. The tip guard 32 includes a plurality of elastic ends 34 extending from a base 36. The tip guard 32 also includes a mounting flange 36 that abuts against the catheter hub 14 and a portion 39 that attaches to the housing 22. Although only two limbs 34 are shown in Figure 2 (a), it is understood that three or more limbs can be provided. The plurality of extremities 34 are spring-driven, whereby the distal ends 40 of each of the extremities are in contact as shown at 42, thus forming a closed chamber 44 within tip guard 32. The limbs 34 are adapted to flex radially outward as shown in Figure 3, to allow the cannula 16 to be inserted into the catheter hub 14 through the tip shield 32. The limbs 34 are flexed radially outward by Mechanical means such as angled jaws, wide enough to allow the cannula to pass through the tip guard without touching the guard.

Each of the extremities 34 includes a retainer 46 extending radially outward from each of the extremity bodies 46. The retainers 46 are clamped within corresponding depressions 50 in the catheter hub 14, when the cannula 16 is inserted through tip guard 32 as shown in Figure 3. The combination of the retainers 46 that coincide within the depressions 50 and the flange 36 resting on the hub 14, lock the tip guard 32 inside the catheter hub 14. As shown in Figure 2 <a), when the cannula 16 is withdrawn from the catheter so that tip 16 is positioned within chamber 44, spring loaded actuation of limbs 34 causes distant ends 40 to contact each other again at 42

-910 with cannula tip 16 secured within closed chamber 44. Thus, tip guard 32 provides both an automatic tip protection mechanism when the cannula is removed from the catheter, as well as an automatic locking mechanism 5 for Attach the tip shield to the catheter hub when the cannula is inserted into the catheter. A gasket 52 is provided within the base of the tip guard to seal the cannula within the tip guard.

Figures 4-11 show an alternative embodiment of the tip guard of the present invention. As shown in Figure 4, the tip guard 54 includes a plurality of ends 56 extending from base 56 to its distant ends 60. Ends 56 are spring-loaded to form a passage 62 extending from base 56 to ends distant 60 from each of the extremities. Each of the limbs 56 also includes a channel 64. The diameter 66 of the passage 62 is smaller than the diameter 66 of the cannula 16. The combination of the channels 64 forms a chamber 70 having a diameter 72 substantially equal to the diameter 66 of the cannula 16. The ends 56 also include seals 74 to lock into the corresponding depressions in the catheter hub (not shown).

As shown in Figure 5, limbs 56 are adapted to flex radially outward to allow cannula 16 to be inserted through the

-10il tip guard 54. As stated above, mechanical means, such as angled jaws, are used to flex ion the extremities radially outward, enough to allow the cannula to pass through the tip guard without touching the extremities. 56. As shown in Figure 6, after the cannula 16 is inserted through the tip guards 54, the limbs 56 are released from the angled jaws and are spring returned to contact the outer surface of the cannula 16. The limbs 56 in this position expand slightly radially thereby placing a slight spring tension on the cannula. This tension provides a tight fit but still allows the cannula to be inserted into the catheter and removed from the catheter through tip shield 54. As shown in Figure 7, once cannula 16 is removed, so that the tip is within tip guard 54, tips 56 are spring returned to their original driven position. Cannula 16 is then secured within chamber 70 formed by channels 64. As can be seen in Figure 7, passage 62 is smaller in diameter than the outer diameter of cannula 16 and reinsertion through the distal ends 60 of limbs 56 is avoided. If reattachment is attempted, the Tip 16 will bump against end walls 76 of channels 64 and therefore will not re-emerge from tip guard 54.

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Figure 8 is a cross-sectional view of the tip guard 54 of Figure 4 taken along lines 8-8. Distant ends 60 are shown with passage 62 having a diameter 66. Figure 9 shows a cross section of the tip guard 54 of Figure 4 taken along lines 9-9. Extremities 56 are shown with seals 74 protruding from limb bodies to couple corresponding depressions in the catheter hub. Chamber 70 is shown, which has a diameter 72 smaller than the diameter 66 of passage 62. Figure IO is a cross-sectional view taken along lines 10-10 of Figure 4, showing the base 58 and includes a joint 76 contained in the joint wall 78. The passage 62 and the channel 70 are visible through a central opening in it. 15 board 76. FIG. 11 is a cross-sectional view of a rear portion 60 of tip guard 54 taken along lines 11-11 of FIG. 4. A notch 62 is provided to attach cannula guard 30 to guard. tip 54 by snap fit. The posterior portion 60 in this embodiment is composed of a U-shaped member having triangular ribs 61, which are fixed in the complementary notches in the housing 22.

As noted above, the retainer on the extremities and the corresponding depression in the catheter hub provide locking means for coupling the tip shield to the catheter hub. The construction of

-1213 detent-depression shown for example in figure 3, has a relatively severe depth and angle. An alternative construction is shown in FIG. 12 where a shallow rounded retainer 64 and a corresponding depression 66 are provided. For example, the retainer and depression may be small enough in depth to .002 to .006. A shallow detent depression could simply be molded so that a direct pull and a simple mold can be used for both tip protection and catheter hub. Additionally, a rounded design will allow the tip guard to be removed from the catheter hub prematurely with some force, if necessary, but could not be easily decoupled. In the mold to form a rounded detent tip guard, the cutout can be easily detached by pulling on the blades that form the core. The pull of these blades could leave a hole in the plastic that could facilitate the ejection of the cutout.

Figure 13 shows a basic catheter hub 66, the only difference between the normal hub and the hub used in the present invention being the depression 90. As with the tip guard, if a rounded depression is provided, a pull can be used. straight into the mold without crushing the coils or special tool.

Figures 14-19 show one embodiment of catheter housing 20 shown in Figure 1. An end view of housing 90 is shown in Figure 14.

-1314 cannula 16 runs through the center of the housing and depression 92 is provided to receive the blood expansion chamber. Seals 91 and grooves 93 hold the cannula guard in place and in conjunction with the notch 96 allow the cannula to move back and forth evenly. Fig. 15 is a cross-sectional view of housing 90 taken along lines 15-15 of Fig. 14. The passageway 94 is provided to insert the cannula, and the notch 96 as previously established receives the cannula protection. Figure 16 is a cross-sectional view of housing 90 taken along lines 16-16 of Figure 14. Staggered regions 96 provide end holes, where the user holds the housing to insert the cannula into the catheter and remove the catheter cannula.

The notches 100 receive ribs 61 on the tip guard. Fig. 17 is a cross-sectional view taken along lines 17-17 of Fig. 16, showing notches 100 to receive the triangular ribs 61 that hold the tip guard secured to the cannula guard. A hole 102 is provided to receive the blood chamber. Figure 16 is a cross-sectional view taken along lines 16-16 of Figure 16, showing hole 102, retainers 91, and grooves 93. Figure 19 is a cross-sectional view taken at along lines 19-19 of Figure 16, which shows area 104 cut to allow easy deflection-free molding of

-1415 steel.

Since the tip guard will completely surround and encapsulate the sharp tip of the cannula, the cannula guard according to another aspect of the present invention will only surround the arrow on the cannula on one side. This aspect of the invention is shown in Figures 20 (a) and 20 (b). Figure 20 (a) shows the cannula 16 partially extending into the blood expansion chamber 2 <+. Cannula guard 30 does not completely surround cannula 16 or blood expansion chamber 2L but only surrounds a portion of cannula 16. In the preferred embodiment, cannula guard 30 surrounds less than half of the circumference of the Cannula 16. Having the cannula guard on only one side of the cannula allows for a lightweight, slim and compact catheter assembly that allows for a low insertion angle. Also shown in figure 20 (a) is the retainer 105 that limits the forward movement of the protection with respect to the housing.

The catheter assembly of the present invention provides many advantages over the prior art. The flattened nose design provides an automatic protection mechanism that protects the tip of the cannula regardless of insertion technique. In addition, the tip guard also provides automatic locking of the guard to the catheter hub. The catheter assembly is thin, light and compact and allows a very low oblique insertion angle. The assembly

-1516 has an easily visible, levelable, very large and long blood expansion chamber. In addition, the palm of the hand is prevented from moving the catheter over the cannula during insertion. The user can see the cannula directly during insertion since it is a transparent material and / or a different color between the cannula mechanism and the protection mechanism so that the operation is intuitive. The catheter assembly of the present invention is inexpensive and simple to manufacture and mold as well as to assemble. Protection with one side allows the blood chamber to be very large. Furthermore, the blood chamber is longer than the protection of the cannula, preventing accidental advance.

During operation, as shown in Figure 21, the catheter assembly is initially provided with the cannula extended through tip shield 26, catheter hub 1U, and catheter 12. Catheter 12 and cannula 16 are initially inserted into vein 106. Once cannula 16 is inserted into vein 106, blood will be seen to fill the chamber with 2 * + blood as indicated at 106. Cannula 16 can then be threaded into vein 106 by pushing or pulling on catheter hub 14 or cannula guard 30 since the IL catheter hub is still locked to tip guard 26. Once catheter 12 is properly positioned as shown in Figure 22, cannula 16 is then removed from catheter 12. Removal of the cannula is controlled by backward movement of the housing, which is limited

-1617 by retainer 105 on shield 30. When cannula 16 passes into tip guard 26, ends 46 are flattened releasing tip guard 26 from catheter hub 14, automatically protecting sharp tip 16 as shown in Figure 23. Catheter 12 and catheter hub 14 are left in the patient and the locked and protected catheter assembly is then discarded.

Since illustrative embodiments of the present invention have been described and illustrated, it will be apparent to those skilled in the art that variations and modifications are possible without departing from the spirit and principle of the present invention, which should be limited only by the scope of the appended claims.

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NOVELTY OF THE INVENTION