CA2099075A1 - Catheter with improved flash plug - Google Patents
Catheter with improved flash plugInfo
- Publication number
- CA2099075A1 CA2099075A1 CA 2099075 CA2099075A CA2099075A1 CA 2099075 A1 CA2099075 A1 CA 2099075A1 CA 2099075 CA2099075 CA 2099075 CA 2099075 A CA2099075 A CA 2099075A CA 2099075 A1 CA2099075 A1 CA 2099075A1
- Authority
- CA
- Canada
- Prior art keywords
- needle
- plug
- distal end
- catheter
- housing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 230000004888 barrier function Effects 0.000 claims description 8
- 239000012530 fluid Substances 0.000 claims description 2
- 238000003780 insertion Methods 0.000 claims 2
- 230000037431 insertion Effects 0.000 claims 2
- 239000008280 blood Substances 0.000 abstract description 14
- 210000004369 blood Anatomy 0.000 abstract description 14
- 239000012528 membrane Substances 0.000 abstract description 6
- 230000000712 assembly Effects 0.000 abstract description 4
- 238000000429 assembly Methods 0.000 abstract description 4
- 238000013022 venting Methods 0.000 description 9
- 210000003811 finger Anatomy 0.000 description 8
- 210000003462 vein Anatomy 0.000 description 5
- 210000004204 blood vessel Anatomy 0.000 description 4
- 230000006378 damage Effects 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 4
- 206010069803 Injury associated with device Diseases 0.000 description 3
- 238000001802 infusion Methods 0.000 description 3
- 238000010276 construction Methods 0.000 description 2
- 208000014674 injury Diseases 0.000 description 2
- 238000001990 intravenous administration Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 208000030507 AIDS Diseases 0.000 description 1
- 208000012260 Accidental injury Diseases 0.000 description 1
- 208000035049 Blood-Borne Infections Diseases 0.000 description 1
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 210000004247 hand Anatomy 0.000 description 1
- 208000006454 hepatitis Diseases 0.000 description 1
- 231100000283 hepatitis Toxicity 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000002560 therapeutic procedure Methods 0.000 description 1
- 210000003813 thumb Anatomy 0.000 description 1
Landscapes
- Media Introduction/Drainage Providing Device (AREA)
Abstract
CATHETER WITH IMPROVED FLASH PLUG
ABSTRACT OF THE DISCLOSURE:
A catheter device is described with a safety needle guard that covers and protects the needle after use of the device. The device includes a semi-tubular needle housing containing a flash chamber with a hollow needle extending from the distal end of the flash chamber. A tubular needle guard concentrically fits and slides within the needle housing. The needle guard has a longitudinal slot through which the mounting base of the flash chamber passes as the guard slides within the housing. The top of the semi-tubular housing is open so that a user may access the top of the tubular needle guard with a finger to urge the needle guard to an extended position from the distal end of the housing and in a surrounding position about the needle. As the needle guard attains its fully extended position about the needle, it locks in place in the needle housing. The flash plug assembly is improved to prevent blood covering the plug, by providing membrane means, which protect the plug and a vent hole which allows communication of the flash chamber and the porous plug, and also may be used in other catheter assemblies which do not employ a needle guard.
ABSTRACT OF THE DISCLOSURE:
A catheter device is described with a safety needle guard that covers and protects the needle after use of the device. The device includes a semi-tubular needle housing containing a flash chamber with a hollow needle extending from the distal end of the flash chamber. A tubular needle guard concentrically fits and slides within the needle housing. The needle guard has a longitudinal slot through which the mounting base of the flash chamber passes as the guard slides within the housing. The top of the semi-tubular housing is open so that a user may access the top of the tubular needle guard with a finger to urge the needle guard to an extended position from the distal end of the housing and in a surrounding position about the needle. As the needle guard attains its fully extended position about the needle, it locks in place in the needle housing. The flash plug assembly is improved to prevent blood covering the plug, by providing membrane means, which protect the plug and a vent hole which allows communication of the flash chamber and the porous plug, and also may be used in other catheter assemblies which do not employ a needle guard.
Description
2099Q7~
CATHETER WITH IMPROVED F~ASH PLUG
FIE~D OF THE INVENTION
This invention relates to intravascular (I.v.) catheters and, in particular, to I.V. catheter assemblies which cover the needle point after use to prevent accidental injury from used needles.
BACKGROUN~ OF THE INVENTION
Intravenous catheters for the infusion of fluids into the peripheral veins of a patient are one of the most common devices used in I.V. therapy. I.V. catheters may b~
produced in two general forms: through-the-needle catheters, in which a catheter is threaded through the needle cannula and into the vein of a patient, and over-the-needle catheters, in which the needle and concentric outer catheter are inserted into the vein and the needle is withdrawn through the emplaced catheter.
A typical over-the-needle I.V. catheter assembly requires the user to remove and then dispose of a contaminated needle after the needle tip and catheter are properly located in a blood vessel of a patient. Once the needle is withdrawn from the catheter, the user's immediate priorities are infusion set connection and site preparation, including the taping of the catheter to the patient. Because of the urgency of these procedures, the needle is normally just dropped conveniently nearby and then retrieved later. Since the needle at this time is exposed and located close to where the user is completing woxk with the catheter, accidental self-inflicted needle injuries are not uncommon. For reasons of the 20~9075 desirability of protecting the user from exposure to blood borne disease such as hepatitis and AIDS, there is an increasing need to protect the user from accidental needle injury.
A catheter design which is directed toward this need is shown in Luther, United States Patent number 4,762,516.
The catheter shown in this application includes an elongate body which houses a sliding needle guard. In use, the needle with its surrounding catheter tube is inserted through the skin of a patient until the tip of the needle is located in a blood vessel, a position detected by a small flow of blood through the needle and into the flash chamber of the catheter. The user then advances a tab on the top of the needle guard to simultaneously thread the catheter tube into the blood vessel and begin the retraction of the needle from the catheter tube. As the needle is withdrawn from the emplaced catheter, the advance of the tab slides the needle guard out of the housing and along the needle, until the distal end of the guard covers the needle tip and the proximal end of the guard locks in the elongate body. The needle and guard may then be set aside with the needle tip fully protected.
While the arrangement described in Luther '516 can provide full protection against accidental needle injury, it is sometimes desirable to provide such a catheter in a smaller, smoothly operating configuration which can be readily manipulated by small hands. In accordance with the principles of Ducharme et al., U.S. Patent No 5,000,740, a catheter assembly with needle guard is provided with a semi-tubular needle housing that is open on the upper surface. Located within the housing is a .
- ;, , . : :: ,, :
2~99075 flash chamber with a needle extending from the distal end of the chamber and beyond the distal end of the housing.
A tubular needle guard is located for distal movement within the semi-tubular needle housing, and has a distal opening through which the needle extends. The bottom of the needle guard is slotted to fit around the base of the flash chamber. At the rear of the needle guard slot is a portion of a locking mechanism which will engage with and lock in the needle housing when the needle guard is extended to cover the needle.
In a preferred embodiment of the Ducharme et al. '740 invention, the needle guard includes a separate tip piece which enables the mounting of a catheter hub over the needle guard tip. The use of a separate tip also facilitates automated assembly without damage to the sharp pointed needle. When the needle guard is extended, the distal end of the tip piece extends beyond the point of the needle. The needle housing of the preferred embodiment also includes an integral, contoured finger grip located on each side of the needle housing. The catheter assembly is further provided with a protective sheath to protect the catheter and needle prior to use.
Yet, a perceived need not met by Ducharme et al. '740 is to provide a compact unit comprising a catheter with a needle guard, such that the unit may fit comfortably within the hand of the user. However, in certain instances, it may still be necessary to provide a compact needle guard which is extensible to longer lengths than a "typical" needle guard. This may be true, for instance, when the user must rely on a longer length needle; or, if a side port is being used, such that more reliable flow patterns may be discerned by a longer flash chamber. Or, ~ ' .
209907~
perhaps, conversely the user requires less space for storage, and yet still needs a typical length needle guard.
As described in Ducharme '740, there is contained a hollow flash chamber closed by a porous flash plug. The basic concept of the porous plug type flashplug is covered under Patent No. 4,917,671 issued to Chang, and incorporated herein by reference. Any such flashplug that has an air path that is axial with the needle cannula and the air venting means has a potential problem that can cause them to fail. It is not uncommon that during a venipuncture of an intravenous catheter, there may be a sudden drop of blood expelled through the proximal end of the cannula.
This drop of blood is sometimes expelled with enough force that it lands on the surface of the porous flashplug and coats it. Once the plug is coated it stops venting air and there can be no additional flashback of blood. The user can then possibly think that the cannula is not situated in the vein, because the normal filling of the flash chamber doesn't take place. When this occurs, the user usually will continue to search for a vein and a flash of blood. Eventually the user will stop using the current catheter device, discard the catheter as a failure, and perhaps try a new catheter.
SUMMARY OF THE INVE~TION
It is therefore an object of this invention to prevent the above described flashback problem. This is accomplished in a catheter device, ideally a protected (or needle-guard) catheter device which contains an improved flash plug at the proximal end of the flash chamber contained in the needle housing. Of course, the flash plug of the ~ :-::
209YOrl~;
present invention is also useable in conventional catheter assemblies which employ a flash plug. This porous plug contains a through hole, which allows venting of the plug without blood leakage, and yet also contains a barrier mechanism, which prevents premature clogging of the flash plug by blood extracted from the body.
The inventions are described herein will be better understood from the attached drawings and the Detailed Description of the Invention.
~SCRIPTION OF THE DRAWINGS:
FIGURE 1 is perspective view of a catheter assembly constructed in accordance with the principles of the present invention with the sheath in place;
FIGURE 2 is a perspective view of the catheter assembly of FIGURE 1 after removal of the sheath;
FIGURE 3 is a perspective view of the needle housing, needle, and needle guard of the catheter assembly of FIGURE 2 with the catheter removed;
; 25 FIGURE 4 is a perspective view of the assembly of FIGURE
CATHETER WITH IMPROVED F~ASH PLUG
FIE~D OF THE INVENTION
This invention relates to intravascular (I.v.) catheters and, in particular, to I.V. catheter assemblies which cover the needle point after use to prevent accidental injury from used needles.
BACKGROUN~ OF THE INVENTION
Intravenous catheters for the infusion of fluids into the peripheral veins of a patient are one of the most common devices used in I.V. therapy. I.V. catheters may b~
produced in two general forms: through-the-needle catheters, in which a catheter is threaded through the needle cannula and into the vein of a patient, and over-the-needle catheters, in which the needle and concentric outer catheter are inserted into the vein and the needle is withdrawn through the emplaced catheter.
A typical over-the-needle I.V. catheter assembly requires the user to remove and then dispose of a contaminated needle after the needle tip and catheter are properly located in a blood vessel of a patient. Once the needle is withdrawn from the catheter, the user's immediate priorities are infusion set connection and site preparation, including the taping of the catheter to the patient. Because of the urgency of these procedures, the needle is normally just dropped conveniently nearby and then retrieved later. Since the needle at this time is exposed and located close to where the user is completing woxk with the catheter, accidental self-inflicted needle injuries are not uncommon. For reasons of the 20~9075 desirability of protecting the user from exposure to blood borne disease such as hepatitis and AIDS, there is an increasing need to protect the user from accidental needle injury.
A catheter design which is directed toward this need is shown in Luther, United States Patent number 4,762,516.
The catheter shown in this application includes an elongate body which houses a sliding needle guard. In use, the needle with its surrounding catheter tube is inserted through the skin of a patient until the tip of the needle is located in a blood vessel, a position detected by a small flow of blood through the needle and into the flash chamber of the catheter. The user then advances a tab on the top of the needle guard to simultaneously thread the catheter tube into the blood vessel and begin the retraction of the needle from the catheter tube. As the needle is withdrawn from the emplaced catheter, the advance of the tab slides the needle guard out of the housing and along the needle, until the distal end of the guard covers the needle tip and the proximal end of the guard locks in the elongate body. The needle and guard may then be set aside with the needle tip fully protected.
While the arrangement described in Luther '516 can provide full protection against accidental needle injury, it is sometimes desirable to provide such a catheter in a smaller, smoothly operating configuration which can be readily manipulated by small hands. In accordance with the principles of Ducharme et al., U.S. Patent No 5,000,740, a catheter assembly with needle guard is provided with a semi-tubular needle housing that is open on the upper surface. Located within the housing is a .
- ;, , . : :: ,, :
2~99075 flash chamber with a needle extending from the distal end of the chamber and beyond the distal end of the housing.
A tubular needle guard is located for distal movement within the semi-tubular needle housing, and has a distal opening through which the needle extends. The bottom of the needle guard is slotted to fit around the base of the flash chamber. At the rear of the needle guard slot is a portion of a locking mechanism which will engage with and lock in the needle housing when the needle guard is extended to cover the needle.
In a preferred embodiment of the Ducharme et al. '740 invention, the needle guard includes a separate tip piece which enables the mounting of a catheter hub over the needle guard tip. The use of a separate tip also facilitates automated assembly without damage to the sharp pointed needle. When the needle guard is extended, the distal end of the tip piece extends beyond the point of the needle. The needle housing of the preferred embodiment also includes an integral, contoured finger grip located on each side of the needle housing. The catheter assembly is further provided with a protective sheath to protect the catheter and needle prior to use.
Yet, a perceived need not met by Ducharme et al. '740 is to provide a compact unit comprising a catheter with a needle guard, such that the unit may fit comfortably within the hand of the user. However, in certain instances, it may still be necessary to provide a compact needle guard which is extensible to longer lengths than a "typical" needle guard. This may be true, for instance, when the user must rely on a longer length needle; or, if a side port is being used, such that more reliable flow patterns may be discerned by a longer flash chamber. Or, ~ ' .
209907~
perhaps, conversely the user requires less space for storage, and yet still needs a typical length needle guard.
As described in Ducharme '740, there is contained a hollow flash chamber closed by a porous flash plug. The basic concept of the porous plug type flashplug is covered under Patent No. 4,917,671 issued to Chang, and incorporated herein by reference. Any such flashplug that has an air path that is axial with the needle cannula and the air venting means has a potential problem that can cause them to fail. It is not uncommon that during a venipuncture of an intravenous catheter, there may be a sudden drop of blood expelled through the proximal end of the cannula.
This drop of blood is sometimes expelled with enough force that it lands on the surface of the porous flashplug and coats it. Once the plug is coated it stops venting air and there can be no additional flashback of blood. The user can then possibly think that the cannula is not situated in the vein, because the normal filling of the flash chamber doesn't take place. When this occurs, the user usually will continue to search for a vein and a flash of blood. Eventually the user will stop using the current catheter device, discard the catheter as a failure, and perhaps try a new catheter.
SUMMARY OF THE INVE~TION
It is therefore an object of this invention to prevent the above described flashback problem. This is accomplished in a catheter device, ideally a protected (or needle-guard) catheter device which contains an improved flash plug at the proximal end of the flash chamber contained in the needle housing. Of course, the flash plug of the ~ :-::
209YOrl~;
present invention is also useable in conventional catheter assemblies which employ a flash plug. This porous plug contains a through hole, which allows venting of the plug without blood leakage, and yet also contains a barrier mechanism, which prevents premature clogging of the flash plug by blood extracted from the body.
The inventions are described herein will be better understood from the attached drawings and the Detailed Description of the Invention.
~SCRIPTION OF THE DRAWINGS:
FIGURE 1 is perspective view of a catheter assembly constructed in accordance with the principles of the present invention with the sheath in place;
FIGURE 2 is a perspective view of the catheter assembly of FIGURE 1 after removal of the sheath;
FIGURE 3 is a perspective view of the needle housing, needle, and needle guard of the catheter assembly of FIGURE 2 with the catheter removed;
; 25 FIGURE 4 is a perspective view of the assembly of FIGURE
3 with the needle guard extended;
FIGURE 5 is a cross-sectional view of the catheter assembly of FIGURE 2; and FIGURE 6 is a perspective view of the new flash plug of the present invention.
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,:
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~ESCRIPTION OF THE INVE~TION:
Referring first to FIGURE 1, a catheter assembly 10 constructed in accordance with the principles of the present invention is shown. The assembly 10 includes a needle housing 20 which is semi-tubular in shape and open at the top. Molded on the sides of the needle housing 20 are opposing contoured finger grips 22, one of which is visible in FIGURE 1. Located inside the semi-tubular needle housing and extending proximally therefrom is a tubular needle guard 30. On the upper surface of the needle guard are a number of small projections 32 which provide surfaces against which a user may press to fully extend the needle guard. These projections permit a user to extend the needle guard with the index or other finger while holding the catheter assembly with one hand.
Extending distally from the needle housing 20 is a protective sheath 40 which covers the distally extending needle and catheter. It is to be emphasized that the flash plug of this invention is not mandated for use with needle guard 30, and, in fact, may be used with any catheter assembly, including catheters similar to assembly lO which do not employ a needle guard.
~` 25 FIGURE 2 illustrates the assembly of FIGURE 1 after removal of the sheath 40. This drawing shows the catheter 50 and its catheter hub 52 mounted on the distal end of the needle guard 30. The point of the needle 24 is seen to extend from the distal tip of the catheter 50. A
push-off tab 34 is seen projecting upward from the needle guard proximal the catheter hub 52.
' ' ~ ,'' . . .
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.
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209907~
FIGURE 3 shows the assembly of FIGURE 2 prior to mounting the catheter and hub on the distal end of the needle guard. Located on the distal end of the needle guard is a needle guard tip 60, through which the needle 24 extends. FIGURE 4 shows the assembly of FIGURE 3 after the needle guard 30 has been extended to cover the needle 24~ In this position the needle guard is locked in its extended po~ition inside the needle housing, and the point of the needle is located inside of the needle guard tip 60.
FIGURE 5 is a cross-sectional view of the catheter assembly of FIGURE 2. The catheter 50 is seen to extend from the distal end 54 of the catheter hub 52 and is lS concentric therewith. The catheter may be attached to its hub by any means known in the art, including adhesively or mechanically by means of a metal eyelet. The larger diameter proximal portion 56 of the catheter hub 52 is flanged at its proximal end for connection to an infusion set, and the inner diameter of the proximal portion of the hub is sized to fit over the distal portion of the needle guard tip 60.
The needle 24 is attached to the distal end of the flash chamber 26 of the needle housing with the proximal end of the needle terminating within the cha~ber. The needle 24 is aff$xed in place by adhesive 28. The needle extends through the needle guard tip 60, the needle hub 52, and the catheter 50, with the point of the needle extending from the distal end of the catheter. The rear of the flash chamber 26 is plugged by a microporous plug 70. The needle guard is seen to extend proximal the rear of the needle housing with the needle guard tip 60 affixed to the distal end of the needle guard at the location of the - ~ ~
209907~
push-off tab 34. The tubular needle guard surrounds the flash chamber 26, with the base 27 of the flash chamber being located in a longitudinal slot 36 at the bottom of the needle guard. As the needle guard slides in the S distal direction to cover the needle it is maintAined concentric with the needle housing by the concentric tubular construction of the needle housing and needle guard and by the tracking of the base 27 of the flash chamber in the needle guard slot 36.
The subassembly of the needle 24, the needle housing 20, the needle guard 30, the porous flash plug 70, and the needle guard tip 60. Assembly may be accomplished by inserting the flash plug 70 into the proximal end of the flash chamber 26. The needle 24 is inserted into the distal end of the flash chamber and is adhesively secured in place. With the needle and housing oriented vertically, the needle guard 30 is dropped over the needle. The large internal opening of the needle guard minimizes the possibility of contact between the needle guard and the point of the needle, which is important to prevent damage to the sharp needle point during assembly.
The needle guard then slides into the needle housing from the distal end of the housing. The tapered distal end 84 of the flash chamber base engages the proximal end of the guard slot 36 to guide the needle guard into the housing around the base 27 of the flash chamber. The guard and housing slides together until the narrowed proximal end 92 of the slot engages the aperture 74 of the housing, causing the two co~ponents to lock together. An instrument is inserted into the aperture 74 and into slot 36 to spread the narrowed portion 92 of the slot and thereby permit the needle guard to proceed fully into the needle housing.
~RK-174 , .
: 209907~
g However, the concentric tubular construction of the needle guard and housing also permits the needle guard to slide into the housing from the proximal end of the housing.
This is preferable to the distal entry technique described above, for the catheter device can then be assembled without causing the needle guard to pass through its locking position, thereby obviating the need to unlock the narrowed portion 92 of the guard slot during assembly of the device.
With the distal end of the needle guard extending beyond the di~tal end of the housing, the needle guard tip 60 is dropped over the point of the needle. The small tip can be accurately aligned with its central passageway in line with the needle so that the guard tip can be slipped over the needle without damaging the point of the needle. When the proximal end 62 of the guard tip fully engages the distal opening 90 of the needle guard these two components are ultrasonically welded together. This two-component needle guard thus permits assembly of the catheter device without damage to the needle. The needle guard and tip then slide fully into the needle housing. The catheter 50 and h~b 52 are then slipped over the needle 24 until the catheter hub 52 is securely seated over the tapered surface 64 of the needle guard tip, as shown in FIGURE 5.
The protective sheath may then be slipped over the catheter and needle and snapped onto the needle housing flange 72. The catheter assembly is then packaged for delivery to a user.
The catheter assembly of FIGURE S may be used in the conventional ~anner by inserting the concentric catheter and needle through the skin of a patient and into a blood vessel. When the point of the needle 24 is properly .:
209907~
located in the vessel, a small amount of blood will flow through the needle and into the flash chamber 26. Since the needle housing and guard are made of transparent or translucent polymeric materials, the flow of blood will be S readily apparent in the flash chamber. The needle is then retracted from the vessel and the catheter 50 threaded into the vessel by grasping the finger grips 22 of the housing with the thumb and fingers and pushing the push-off tab 34 in the distal direction with one finger.
This motion will push the catheter hub 52 off of the needle guard tip 60 to advance the catheter. As the needle guard begins to extend out from the distal end of the needle houæing such that the push-off tab 34 is beyond the reach of the finger of the user, the user may engage lS the projections 32 with the finger to continue the distal motion of the needle guard.
Finally this motion will result in proper threading of the catheter into the vessel and the complete withdrawal of the needle from the patient's body. The needle guard 30 is then advanced to its fullest extension. As it does so, the tapered proximal section 82 of the flash chamber base will spread the narrowed proximal portion 92 of the needle guard slot 36 until the narrowed portion 92 finally engages the aperture 74. At the fullest extension of the needle guard from the housing the engagement of the narrowed portion 92 in the aperture 74 will lock the needle guard in its protective position. The needle, housing and guard may then be set aside without concern for inadvertent injury to the user or others.
The present invention is seen in Figure 6, and describes a flashplug 126 that has an axial porous plug 128, for venting and a distal membrane 130 that partially occludes 209907~
the axial air path. The membrane 130 serves as a barrier to stop any drop of blood that might be expelled upon initial venipuncture from needle 24, and thereafter coat the end of the porous barrier rendering it non-venting.
The membrane 130 principally covers the main axial portion of the distal end of the flashplug 126. There is at least one, and preferably two vents 132 that are offset to the side of membrane 130, to permit air to vent out of the flash chamber 30 from the needle 24. In one version of this plug 126, the combined cross-sectional area of the vent passages 132 would be slightly larger that the bore of a 16ga cannula, to give the same venting properties that now exist with a porous plug 132 such as flashplug 36. In another version the size of the vents 132 might be tailored to actually throttle the rate of venting achieved. In this version there is adequate initial venting to achieve quick flashback from needle 24. Once blood is present in the flash chamber 30, the rate of fill of the chamber is slowed by the vent 132 sizes. In both cases, blood must follow a tortuous path prior to coating the end of the porous plug 126. This would occur only on filling of the chamber 30, so that plug 128 is never covered.
Therefore, the new plug 126 contains an open chamber 129 distal the distal most end of plug 128. This mechanism, combined with vent holes 132, and membrane 130, insures ; adequate venting, and yet prevents blood sealing the plug 128 to obstruct flash.
It is intended that this invention be described by the attached claims, and their equivalents. As previously mentioned, this is intended to include all types of , ': ' ' ~; :' ' , .: ~
. ~
209907~
catheter assemblies using a flash plug, either with or without a needle guard.
FIGURE 5 is a cross-sectional view of the catheter assembly of FIGURE 2; and FIGURE 6 is a perspective view of the new flash plug of the present invention.
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~ESCRIPTION OF THE INVE~TION:
Referring first to FIGURE 1, a catheter assembly 10 constructed in accordance with the principles of the present invention is shown. The assembly 10 includes a needle housing 20 which is semi-tubular in shape and open at the top. Molded on the sides of the needle housing 20 are opposing contoured finger grips 22, one of which is visible in FIGURE 1. Located inside the semi-tubular needle housing and extending proximally therefrom is a tubular needle guard 30. On the upper surface of the needle guard are a number of small projections 32 which provide surfaces against which a user may press to fully extend the needle guard. These projections permit a user to extend the needle guard with the index or other finger while holding the catheter assembly with one hand.
Extending distally from the needle housing 20 is a protective sheath 40 which covers the distally extending needle and catheter. It is to be emphasized that the flash plug of this invention is not mandated for use with needle guard 30, and, in fact, may be used with any catheter assembly, including catheters similar to assembly lO which do not employ a needle guard.
~` 25 FIGURE 2 illustrates the assembly of FIGURE 1 after removal of the sheath 40. This drawing shows the catheter 50 and its catheter hub 52 mounted on the distal end of the needle guard 30. The point of the needle 24 is seen to extend from the distal tip of the catheter 50. A
push-off tab 34 is seen projecting upward from the needle guard proximal the catheter hub 52.
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.
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209907~
FIGURE 3 shows the assembly of FIGURE 2 prior to mounting the catheter and hub on the distal end of the needle guard. Located on the distal end of the needle guard is a needle guard tip 60, through which the needle 24 extends. FIGURE 4 shows the assembly of FIGURE 3 after the needle guard 30 has been extended to cover the needle 24~ In this position the needle guard is locked in its extended po~ition inside the needle housing, and the point of the needle is located inside of the needle guard tip 60.
FIGURE 5 is a cross-sectional view of the catheter assembly of FIGURE 2. The catheter 50 is seen to extend from the distal end 54 of the catheter hub 52 and is lS concentric therewith. The catheter may be attached to its hub by any means known in the art, including adhesively or mechanically by means of a metal eyelet. The larger diameter proximal portion 56 of the catheter hub 52 is flanged at its proximal end for connection to an infusion set, and the inner diameter of the proximal portion of the hub is sized to fit over the distal portion of the needle guard tip 60.
The needle 24 is attached to the distal end of the flash chamber 26 of the needle housing with the proximal end of the needle terminating within the cha~ber. The needle 24 is aff$xed in place by adhesive 28. The needle extends through the needle guard tip 60, the needle hub 52, and the catheter 50, with the point of the needle extending from the distal end of the catheter. The rear of the flash chamber 26 is plugged by a microporous plug 70. The needle guard is seen to extend proximal the rear of the needle housing with the needle guard tip 60 affixed to the distal end of the needle guard at the location of the - ~ ~
209907~
push-off tab 34. The tubular needle guard surrounds the flash chamber 26, with the base 27 of the flash chamber being located in a longitudinal slot 36 at the bottom of the needle guard. As the needle guard slides in the S distal direction to cover the needle it is maintAined concentric with the needle housing by the concentric tubular construction of the needle housing and needle guard and by the tracking of the base 27 of the flash chamber in the needle guard slot 36.
The subassembly of the needle 24, the needle housing 20, the needle guard 30, the porous flash plug 70, and the needle guard tip 60. Assembly may be accomplished by inserting the flash plug 70 into the proximal end of the flash chamber 26. The needle 24 is inserted into the distal end of the flash chamber and is adhesively secured in place. With the needle and housing oriented vertically, the needle guard 30 is dropped over the needle. The large internal opening of the needle guard minimizes the possibility of contact between the needle guard and the point of the needle, which is important to prevent damage to the sharp needle point during assembly.
The needle guard then slides into the needle housing from the distal end of the housing. The tapered distal end 84 of the flash chamber base engages the proximal end of the guard slot 36 to guide the needle guard into the housing around the base 27 of the flash chamber. The guard and housing slides together until the narrowed proximal end 92 of the slot engages the aperture 74 of the housing, causing the two co~ponents to lock together. An instrument is inserted into the aperture 74 and into slot 36 to spread the narrowed portion 92 of the slot and thereby permit the needle guard to proceed fully into the needle housing.
~RK-174 , .
: 209907~
g However, the concentric tubular construction of the needle guard and housing also permits the needle guard to slide into the housing from the proximal end of the housing.
This is preferable to the distal entry technique described above, for the catheter device can then be assembled without causing the needle guard to pass through its locking position, thereby obviating the need to unlock the narrowed portion 92 of the guard slot during assembly of the device.
With the distal end of the needle guard extending beyond the di~tal end of the housing, the needle guard tip 60 is dropped over the point of the needle. The small tip can be accurately aligned with its central passageway in line with the needle so that the guard tip can be slipped over the needle without damaging the point of the needle. When the proximal end 62 of the guard tip fully engages the distal opening 90 of the needle guard these two components are ultrasonically welded together. This two-component needle guard thus permits assembly of the catheter device without damage to the needle. The needle guard and tip then slide fully into the needle housing. The catheter 50 and h~b 52 are then slipped over the needle 24 until the catheter hub 52 is securely seated over the tapered surface 64 of the needle guard tip, as shown in FIGURE 5.
The protective sheath may then be slipped over the catheter and needle and snapped onto the needle housing flange 72. The catheter assembly is then packaged for delivery to a user.
The catheter assembly of FIGURE S may be used in the conventional ~anner by inserting the concentric catheter and needle through the skin of a patient and into a blood vessel. When the point of the needle 24 is properly .:
209907~
located in the vessel, a small amount of blood will flow through the needle and into the flash chamber 26. Since the needle housing and guard are made of transparent or translucent polymeric materials, the flow of blood will be S readily apparent in the flash chamber. The needle is then retracted from the vessel and the catheter 50 threaded into the vessel by grasping the finger grips 22 of the housing with the thumb and fingers and pushing the push-off tab 34 in the distal direction with one finger.
This motion will push the catheter hub 52 off of the needle guard tip 60 to advance the catheter. As the needle guard begins to extend out from the distal end of the needle houæing such that the push-off tab 34 is beyond the reach of the finger of the user, the user may engage lS the projections 32 with the finger to continue the distal motion of the needle guard.
Finally this motion will result in proper threading of the catheter into the vessel and the complete withdrawal of the needle from the patient's body. The needle guard 30 is then advanced to its fullest extension. As it does so, the tapered proximal section 82 of the flash chamber base will spread the narrowed proximal portion 92 of the needle guard slot 36 until the narrowed portion 92 finally engages the aperture 74. At the fullest extension of the needle guard from the housing the engagement of the narrowed portion 92 in the aperture 74 will lock the needle guard in its protective position. The needle, housing and guard may then be set aside without concern for inadvertent injury to the user or others.
The present invention is seen in Figure 6, and describes a flashplug 126 that has an axial porous plug 128, for venting and a distal membrane 130 that partially occludes 209907~
the axial air path. The membrane 130 serves as a barrier to stop any drop of blood that might be expelled upon initial venipuncture from needle 24, and thereafter coat the end of the porous barrier rendering it non-venting.
The membrane 130 principally covers the main axial portion of the distal end of the flashplug 126. There is at least one, and preferably two vents 132 that are offset to the side of membrane 130, to permit air to vent out of the flash chamber 30 from the needle 24. In one version of this plug 126, the combined cross-sectional area of the vent passages 132 would be slightly larger that the bore of a 16ga cannula, to give the same venting properties that now exist with a porous plug 132 such as flashplug 36. In another version the size of the vents 132 might be tailored to actually throttle the rate of venting achieved. In this version there is adequate initial venting to achieve quick flashback from needle 24. Once blood is present in the flash chamber 30, the rate of fill of the chamber is slowed by the vent 132 sizes. In both cases, blood must follow a tortuous path prior to coating the end of the porous plug 126. This would occur only on filling of the chamber 30, so that plug 128 is never covered.
Therefore, the new plug 126 contains an open chamber 129 distal the distal most end of plug 128. This mechanism, combined with vent holes 132, and membrane 130, insures ; adequate venting, and yet prevents blood sealing the plug 128 to obstruct flash.
It is intended that this invention be described by the attached claims, and their equivalents. As previously mentioned, this is intended to include all types of , ': ' ' ~; :' ' , .: ~
. ~
209907~
catheter assemblies using a flash plug, either with or without a needle guard.
Claims (6)
1. A catheter assembly comprising:
a tubular needle housing having a distal end;
a hollow needle extending from the distal end of said needle housing; and a flash chamber located within said housing, said flash chamber comprising:
a hollow tube with a distal end attached to said needle and an open proximal end; and a flash plug assembly emplaceable in said open proximal end, said flash plug assembly comprising a porous plug placed within a plug holder, said plug holder having an open proximal end for insertion of said plug, a hollow chamber and a distal end for insertion into said hollow tube proximal end, said plug holder distal end having a barrier with vent holes providing communication between said hollow chamber and said hollow tube.
a tubular needle housing having a distal end;
a hollow needle extending from the distal end of said needle housing; and a flash chamber located within said housing, said flash chamber comprising:
a hollow tube with a distal end attached to said needle and an open proximal end; and a flash plug assembly emplaceable in said open proximal end, said flash plug assembly comprising a porous plug placed within a plug holder, said plug holder having an open proximal end for insertion of said plug, a hollow chamber and a distal end for insertion into said hollow tube proximal end, said plug holder distal end having a barrier with vent holes providing communication between said hollow chamber and said hollow tube.
2. The device of claim 1 wherein said vent holes have a cross-sectional area roughly the size of said needle cross-sectional area.
3. The device of claim 1 wherein there are two of said vent holes.
4. The catheter assembly of claim 1, wherein said hollow needle extends from said flash chamber and the passageway of said hollow needle is in fluid communication with the interior of said flash chamber.
5. A flash plug assembly comprising:
a porous plug having a distal end and a proximal end; and a plug holder into which may be inserted said plug, said holder having an open proximal end engageable with said plug distal end and a distal end containing barrier means, said barrier means having vent holes placing the outside of said plug holder in flush communication with said plug distal end.
a porous plug having a distal end and a proximal end; and a plug holder into which may be inserted said plug, said holder having an open proximal end engageable with said plug distal end and a distal end containing barrier means, said barrier means having vent holes placing the outside of said plug holder in flush communication with said plug distal end.
6. A flash chamber assembly, comprising:
a hollow tube having an open distal end and a proximal end engageable with a plug assembly; and a plug assembly comprising:
a porous plug having a distal end and a proximal end; and a plug holder into which may be inserted said plug, said holder having an open proximal end engageable with said plug distal end and a distal end containing barrier means, said barrier means having vent holes placing the outside of said plug holder in flush communication with said plug distal end.
a hollow tube having an open distal end and a proximal end engageable with a plug assembly; and a plug assembly comprising:
a porous plug having a distal end and a proximal end; and a plug holder into which may be inserted said plug, said holder having an open proximal end engageable with said plug distal end and a distal end containing barrier means, said barrier means having vent holes placing the outside of said plug holder in flush communication with said plug distal end.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US904,779 | 1978-05-11 | ||
| US90477992A | 1992-06-26 | 1992-06-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2099075A1 true CA2099075A1 (en) | 1993-12-27 |
Family
ID=25419763
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2099075 Abandoned CA2099075A1 (en) | 1992-06-26 | 1993-06-23 | Catheter with improved flash plug |
Country Status (2)
| Country | Link |
|---|---|
| AU (1) | AU4131693A (en) |
| CA (1) | CA2099075A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113350614A (en) * | 2015-05-15 | 2021-09-07 | C·R·巴德股份有限公司 | Catheter placement device including extendable needle safety feature |
-
1993
- 1993-06-17 AU AU41316/93A patent/AU4131693A/en not_active Abandoned
- 1993-06-23 CA CA 2099075 patent/CA2099075A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113350614A (en) * | 2015-05-15 | 2021-09-07 | C·R·巴德股份有限公司 | Catheter placement device including extendable needle safety feature |
Also Published As
| Publication number | Publication date |
|---|---|
| AU4131693A (en) | 1994-01-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |