Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2002-12-17
2003-11-25
Hayes, Michael J. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S110000, C604S198000
Reexamination Certificate
active
06652490
ABSTRACT:
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 typically are on the order of about two inches or less 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 one technique, the introducer needle and catheter are inserted completely into the blood vessel together. In another technique, the introducer needle is partially withdrawn into the catheter after the initial venipuncture. The catheter is then inserted completely into the blood vessel. 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. The flashback chamber 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 delivery device, a PRN or a deadender cap 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 a contaminated introducer needle 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 compact 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. Typically a porous plug is located in the open proximal end of the flashback chamber to allow air to escape from the flashback chamber when blood enters the flashback chamber from the introducer needle. 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, a discontinuity such as an enlarged diameter portion. The discontinuity cooperates with a needle shield to prevent unwanted proximal and distal 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 needle shield includes a means for engaging the discontinuity on the introducer needle to prevent unwanted proximal and distal movement of the introducer needle once the introducer needle has been proximally withdrawn into the needle shield. Preferably the means for engaging the discontinuity on the introducer needle is a spring clip that has a proximal portion with a small diameter opening formed therein and a distal portion with a small diameter opening formed therein. Both of the openings are too small to allow the discontinuity on the introducer needle to pass therethrough but are large enough to allow the main portion of the introducer needle to pass through.
The proximal portion of the introducer needle extends through the opening in the proximal portion of the spring clip. The distal portion of the spring clip rides along the introducer needle shaft as the introducer needle is retracted into the needle shield. Once the distal end of the introducer needle has been retracted into the needle shield and is proximal of the distal portion of the spring clip, the distal portion of the spring clip can move in front of the sharp distal tip of the introducer needle. The spring clip is configured so the small diameter opening in its distal portion is aligned with the sharp distal tip of the introducer needle. Thus, If the introducer needle is moved distally with respect to the needle shield and the spring clip, the distal end of the introducer needle travels through and past the distal opening formed in the distal portion of the spring clip but is prevented from being moved distally outside of the needle shield when the discontinuity on the introducer needle engages the small diameter opening formed in the distal portion of the spring clip. Similarly, continued proximal movement of the introducer needle with respect to the needle shield is prevented when the discontinuity engages the opening in the proximal portion of the spring clip.
REFERENCES:
patent: 6004294 (1999-12-01), Brimhall et al.
patent: 6379333 (2002-04-01), Brimhall et al.
Becton Dickinson and Company
Ghafoorian Roz
Hayes Michael J.
Murtha James J.
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