WO2001023028A1

WO2001023028A1 - Catheter and dual feature introducer needle assembly with needle shield

Info

Publication number: WO2001023028A1
Application number: PCT/US2000/025541
Authority: WO
Inventors: Greg L. Brimhall; Steven W. Johnson
Original assignee: Becton, Dickinson And Company
Priority date: 1999-09-24
Filing date: 2000-09-18
Publication date: 2001-04-05
Also published as: AU7588900A

Abstract

A catheter and introducer needle assembly with needle shield is provided wherein the needle includes an enlarged diameter portion and a notch defining a distally facing shoulder. The needle shield includes a means for engaging the distally facing shoulder of the notch to prevent unwanted distal movement of the needle once the needle has been withdrawn into the needle shield. The needle shield also includes a means to prevent unwanted proximal movement of the needle once the needle has been withdrawn into the needle shield.

Description

CATHETER AND DUAL FEATURE INTRODUCER NEEDLE ASSEMBLY WITH NEEDLE SHIELD

Background of the Invention

The subject invention relates to a catheter and introducer needle assembly that includes a needle shield that will safely shield the sharp distal tip of the introducer needle after the needle has been used to insert the catheter into a patient.

Catheters, particularly intravenous (IV) catheters, are used for infusing fluid, such as normal saline solution, various medicaments and total parenteral nutrition, into a patient or withdrawing blood from a patient. Peripheral IV catheters tend to be relatively short, and are on the order of about one and one- half inches in length. The most common type of IV catheter is an over the needle peripheral IV catheter. As its name implies, an over the needle catheter is mounted over an introducer needle having a sharp distal tip. The catheter and the introducer needle are assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from the patient's skin.

The catheter and introducer needle assembly is inserted at a shallow angle through the patient's skin into a peripheral blood vessel, i.e a smaller blood vessel that is not connected directly to the heart but is one of the branches of the central blood vessels that is directly connected to the heart. In order to verify proper placement of the assembly in the blood vessel, the clinician confirms that there is flashback of blood in the needle and in a flashback chamber located at the proximal end of the needle, which is typically formed as part of the needle hub. Once proper placement is confirmed, the clinician applies pressure to the blood vessel by pressing down on the patient's skin over the distal tip of the introducer needle and the catheter. This finger pressure occludes further blood flow through the introducer needle. The clinician withdraws the introducer needle, leaving the catheter in place, and attaches a fluid handling device to the catheter hub. Once the introducer needle is withdrawn from the catheter, it is a "blood contaminated sharp" and must be properly handled. In recent years, there has been great concern over the contamination of clinicians with a patient's blood and a recognition that "blood contaminated sharps" must be immediately disposed. This concern has arisen because of the advent of currently incurable and fatal diseases, such as Acquired Immunosuppressive Deficiency Syndrome ("AIDS"), which can be transmitted by the exchange of body fluids from an infected person to another person. Thus, contact with the body fluid of an AIDS infected person must be avoided. As noted above, if an introducer needle has been used to place a catheter in the vein of an AIDS infected person, the introducer needle is a vehicle for the transmission of the disease. Although clinicians are aware of the need to properly handle "blood contaminated sharps", unfortunately in certain medical environments, such as emergency situations or as a result of inattention or neglect, needlesticks with contaminated introducer needles still occur.

As a result of the problem of accidental needlesticks by "blood contaminated sharps", various needle shields have been developed. Generally, such needle shields work for their intended purpose but could be improved. For example, some needle shields are bulky, difficult to use or require special features or techniques to be operative.

Summary of the Invention

It is therefore an object of this invention to provide a needle shield that is compact.

It is another object of this invention to provide a needle shield that is simple and easy to use.

It is still another object of this invention to provide a needle shield that requires no special features or technique to be operative.

The catheter and introducer needle assembly with needle shield of this invention includes a catheter having a distal end and a proximal end connected to the distal end of a catheter hub. The introducer needle has a sharp distal tip and a proximal end connected to the distal end of a needle hub. A flashback chamber is defined in the needle hub. The catheter is coaxially disposed over the introducer needle so the sharp distal tip of the introducer needle is distal of the distal end of the catheter. The introducer needle also defines, along a distal portion thereof, an enlarged diameter portion and a notch with a distally facing shoulder distal of the enlarged diameter portion. The enlarged diameter portion cooperates with a needle shield to prevent unwanted proximal movement of the introducer needle with respect to the needle shield once the introducer needle has been withdrawn into the needle shield after use The notch with its distally facing shoulder cooperates with the needle shield to prevent unwanted distal movement of the introducer needle once the introducer needle has been withdrawn proximally into the needle shield after use Preferably, the notch is distal of the enlarged diameter portion

The needle shield includes a main body portion defining a longitudinally extending passage through which the introducer needle extends The needle shield also includes a means for engaging the distally facing shoulder of the notch of the introducer needle to prevent unwanted distal movement of the introducer needle once the introducer needle has been proximally withdrawn into the needle shield The needle shield also includes a means for engaging the enlarged diameter portion of the introducer needle to prevent unwanted proximal movement of the introducer needle once the introducer needle has been proximally withdrawn into the needle shield

The means for engaging the distally facing shoulder of the enlarged diameter portion of the introducer needle and the means for engaging the enlarged diameter portion of the introducer needle is a tube located in the main body portion of the needle shield The tube is coaxially located in the longitudinal passage of the main body portion and preferably includes at least two movable lanced protrusions or tabs that extend inwardly into the tube Because the tabs are movable, the enlarged diameter portion of the introducer needle can move proximally past the tabs Once the introducer needle has been withdrawn proximally into the needle shield past the enlarged diameter portion, one of the tabs drops into the notch such that the tab is distal of the distally facing shoulder of the notch In this way, any subsequent distal movement of the introducer needle will be prevented by the distally facing shoulder of the notch engaging the tab At least two tabs are used to allow the clinician to rotate the needle with respect the needle shield and the catheter and still ensure that one of the tabs will engage the notch The tube also has a proximal portion that has a diameter sufficient to allow the proximal portion of the introducer needle to extend therethrough but that is too small to allow the enlarged diameter portion of the introducer needle to pass therethrough In this way, any subsequent proximal movement of the introducer needle will be prevented by the enlarged diameter portion engaging the small diameter portion of the tube.

The needle shield is sized so it can fit inside the catheter hub with a friction fit. This ensures that the needle shield remains engaged with the catheter until the introducer needle has been completely removed from the catheter and is safely shielded in the needle shield.

Brief Description of the Drawings

The preferred embodiments are illustrated in the drawings in which like reference numerals refer to like elements and in which:

FIG. 1 is a perspective view of the catheter and introducer needle assembly with needle shield of this invention;

FIG. 2 is an exploded perspective view of the catheter and introducer needle assembly with needle shield of this invention;

FIG. 3 is an enlarged cross-sectional view of the needle shield located in the catheter hub with the sharp distal tip of the introducer needle located distal of the needle shield;

FIG. 4 is an enlarged cross-sectional view of the needle shield removed from the catheter hub with the enlarged diameter portion of the introducer needle engaged with the small diameter proximal portion of the tube preventing unwanted proximal movement of the introducer needle out of the needle shield;

FIG. 5 is an enlarged cross-sectional view of the needle shield similar to FIG. 4 but showing engagement of one of the tabs of the tube with the distally facing shoulder of the notch preventing unwanted distal movement of the introducer needle out of the needle shield; and

FIG. 6 is a perspective view of the tube that is used to lock the introducer needle in the needle shield.

Detailed Description of the Invention

As used herein, the term "proximal" refers to a location on the catheter and introducer needle assembly with needle shield of this invention closest to the clinician using the device and farthest from the patient in connection with whom the device is used when the device is used in its normal operation. Conversely, the term "distal" refers to a location on the catheter and introducer needle assembly of this invention farthest from the clinician using the device and closest to the patient in connection with whom the device is used when the device is used in its normal operation.

The catheter and introducer needle assembly of this invention is identified generally by the numeral 10. It includes a catheter assembly 20 and an introducer needle assembly 30 that includes a needle shield 40.

Catheter assembly 20 includes a catheter 21 that has a proximal end, a distal end and a catheter hub 24 affixed to the proximal end of catheter 21. Suitable materials for catheter 21 include, but are not limited to, thermoplastic resins such as polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer (FEP), polyurethane and the like. Preferably, catheter 21 is formed from a thermoplastic hydrophilic polyurethane that softens with exposure to physiological conditions present in the patient's body. Suitable materials for catheter hub 24 include, but are not limited to, thermoplastic polymeric resins such as polycarbonate, polystyrene, polypropylene and the like. Catheter hub 24 may include a radially outwardly extending tab, not shown, which is useful for advancing catheter 21 into the patient's blood vessel.

Introducer needle assembly 30 includes introducer needle 31 having a sharp distal tip defined by bevel 32 and a proximal end connected to needle hub 34. Introducer needle 31 is preferably formed from stainless steel. Needle hub 34 can include an integrated flashback chamber 35. Needle hub 34 is preferably formed from the same types of materials that are used to form catheter hub 24.

Introducer needle assembly 30 also includes needle shield 40 which includes main body portion 41 and which in turn defines a longitudinally extending passage 42 having a proximal opening 43 and a distal opening 44. This allows introducer needle 31 to extend longitudinally through main body portion 41. The diameter of main body portion 41 is approximately the same size as the diameter of the inside of catheter hub 24. However, preferably needle shield 40 is friction fitted inside catheter hub 24 so needle shield 40 can remain snugly fitted inside catheter hub 24. This way, needle shield 40 remains engaged with catheter hub 24 while introducer needle 31 is moved proximally until the sharp distal tip of introducer needle 31 is trapped inside needle shield 40.

Introducer needle 31 includes a notch 37 defining a distally facing shoulder 37a and an enlarged diameter portion 38. Notch 37 is located distal of enlarged diameter portion 38. Preferably, enlarged diameter portion 38 is formed on introducer needle 31 by centerless grinding a larger diameter introducer needle.

The means for engaging distally facing shoulder 37a of notch 37 and the means for engaging enlarged diameter portion 38 of introducer needle 31 is a tube 50 located in needle shield 40. Preferably, tube 50 is formed from stainless steel, although other relatively rigid material that can be formed with a flexible portion can be used. Tube 50 is press fit into needle shield 40 so that tube 50 is coaxially located in longitudinally extending passage 42. Tube 50 includes at least one movable lanced tab 51 that extends inwardly into tube 50 and flanges 52 that flare outwardly from tube 50. Preferably two such tabs 51 are formed on opposite sides of tube 50. This ensures that at least one of such tabs 51 engages notch 37 even if the clinician rotates introducer needle 31 with respect to needle shield 40. Because tabs 51 are movable, enlarged diameter portion 38 can move past the proximal ends of tabs 51 as introducer needle 31 is withdrawn proximally into needle shield 40. Once introducer needle 31 has been withdrawn proximally into needle shield 40 such that tabs 51 are distal of distally facing shoulder 37a of notch 37, one of tabs 51 will extend into notch 37. Thus, any subsequent distal movement of introducer needle 31 will be prevented by the engagement of the proximal end of one of tabs 51 with distally facing shoulder 37a of notch 37.

Tube 50 also includes a proximal portion 55, which has a diameter that is smaller than the diameter of enlarged diameter portion 38. However, the diameter of proximal portion 55 is large enough to allow the proximal portion of introducer needle 31 to pass therethrough. Thus, further proximal movement of introducer needle 31 is prevented by the engagement of enlarged diameter portion 38 with proximal portion 55 of tube 50. Alternatively, main body portion 41 of needle shield 40 could be formed with a proximal opening having a diameter smaller than the diameter of enlarged diameter portion 38 to prevent enlarged diameter portion 38 from passing through proximal opening 43.

In an alternative embodiment, tube 50 is used as the needle shield without main body portion 41. In this embodiment, tube 50 is located in catheter hub 24 with flanges 52 engaging the inside of catheter hub 24 so tube 50 remains inside catheter hub 24 until the sharp distal tip of introducer needle 31 is safely trapped inside tube 50. In order to place catheter 21 into a patient's blood vessel, the clinician substantially longitudinally aligns introducer needle 31 and catheter 21 with the target blood vessel. Bevel 32 should be facing substantially away from the skin surface during venipuncture. The clinician inserts introducer needle 31 and catheter 21 at a shallow angle, preferably less than about 35 degrees, into the skin so that the sharp distal tip of introducer needle 31 enters the target blood vessel. The clinician will observe blood flashback in the flashback chamber of needle hub 34 if the venipuncture is successful.

After confirming placement of introducer needle 31 and catheter 21 in the target blood vessel, the clinician advances catheter 21 distally axially along introducer needle 31 into position in the blood vessel. After proper placement of catheter 31 is achieved, the clinician places a finger from her other hand on the patient's skin over the blood vessel approximately over distal end of catheter 31. By placing her finger on the patient's skin and applying sufficient pressure on the skin, the clinican thereby substantially occludes blood flow through catheter 31. The clinican then withdraws introducer needle 31 from catheter 21 by moving needle hub 34 proximally. This movement causes introducer needle 31 to move proximally into needle shield 40. However, the friction fit between needle shield 40 and catheter hub 24 ensures that needle shield 40 remains engaged with catheter hub 24 until the sharp distal tip of introducer needle 31 is moved proximally into needle shield 40. Continued proximally directed force applied to needle hub 34 causes enlarged diamter portion 38 to engage proximal portion 55 and transmits enough force to needle shield 40 so that it becomes disengaged from catheter hub 24. At this point, the sharp distal tip 32 is locked in needle shield 40. After introducer needle 31 and needle shield 40 have been removed from catheter hub 24, the clinician may then attach any desired fluid handling device to catheter hub 24 and commence the planned treatment. Introducer needle 31 and needle shield 40 may then be disposed of according to the facility's disposal protocol.

Thus, it is seen that a catheter and introducer needle assembly with needle shield is provided that is compact, simple and easy to use and that requires no special features or technique to be operative.

Claims

We Claim:

1. A catheter and introducer needle assembly, comprising: a catheter having a proximal end and distal end; a catheter hub in fluid communication with the catheter and having a proximal end and a distal end connected to the proximal end of the catheter; an introducer needle disposed in the catheter and having a proximal end and a distal end and defining an enlarged diameter portion and a notch with a distally facing shoulder, wherein the notch is distal of the enlarged diameter portion; a needle shield having a proximal end and a distal end removably connected to the catheter hub, the needle shield defining a longitudinally extending passageway therethrough with the introducer needle extending through the longitudinally extending passageway wherein the needle shield includes a means for engaging the enlarged diameter portion of the introducer needle to prevent unwanted proximal movement of the introducer needle and wherein the needle shield includes a means for engaging the distally facing shoulder of the notch to prevent unwanted distal movement of the introducer needle.

2. The catheter and introducer needle assembly of claim 1 wherein the means for engaging the enlarged diameter portion of the introducer needle to prevent unwanted proximal movement of the introducer needle is a proximal portion of the longitudinally extending passageway that has a diameter smaller than the diameter of the enlarged diameter portion of the introducer needle.

3. The catheter and introducer needle assembly of claim 1 wherein the means for engaging the distally facing shoulder of the notch to prevent unwanted distal movement of the introducer needle is at least two inwardly directed tabs.

4. A needle shield assembly, comprising: a needle having a proximal end and a distal end and defining an enlarged diameter portion and a notch defining a distally facing shoulder, wherein the notch is distal of the enlarged diameter portion; and a needle shield defining a longitudinally extending passageway therethrough with the needle extending through the longitudinally extending passageway wherein the needle shield includes a proximal portion with a diameter less than the diameter of the enlarged diameter portion and wherein the needle shield defines at least two inwardly directeds tabs.