IV catheter abstract
An improvement is set forth in a peripheral IV catheter assembly
which comprises a needle hub having proximal and distal ends and
a central bore having a flashback chamber, blood in said chamber
being observable through said needle hub. A needle extends from
the distal end of the bore. A catheter hub fits about the needle
and has its proximal end held by the distal end of the needle hub.
A cannula fits about the needle with its proximal end engaged with
the distal end of the catheter hub. A flashback plug has proximal
and distal ends. Its distal end can engage with the proximal end
of the needle hub in blocking relation to the needle hub bore. A
protector has a proximal end engagable with the distal end of the
needle hub with the passage about the catheter hub, the needle and
the cannula. The improvement comprises wherein the distal end of
the protector is engageable with the proximal end of the needle
hub with the central passage in the protector in flow communication
with the central bore in the needle hub. The protector is such that
blood in the passage is observable through the protector. The flashback
plug is adapted intermediate its ends to engage in the passage in
the protector. The flashback chamber is extended by connecting it
to the central passage in the protector. Also, the flashback plug
can be used in the protector to protect against contamination.
IV catheter claims
I claim:
1. In a peripheral IV catheter assembly which comprises a longitudinally
extending needle hub having a proximal end, a distal end and a central
bore having a flashback chamber, the needle hub being of a construction
such that an observer can observe blood in said flashback chamber;
a needle held by said central bore of said needle hub adjacent said
distal end of said needle hub and extending longitudinally therefrom;
a catheter hub having a proximal end, a distal end and a central
bore, said catheter hub fitting about said needle and having its
proximal end held by said distal end of said needle hub; a cannula
having a proximal end, a distal end and a central bore, said cannula
fitting about said needle with said proximal end thereof engaged
with said distal end of said catheter hub; a flashback plug having
a proximal end and a distal end, said distal end of said flashback
plug being of a construction such that it engages with said proximal
end of said needle hub in blocking relationship with said bore of
said needle hub; and a protector having a proximal end, a distal
end and a central passage, said proximal end of said protector being
of a construction such that it engages with said distal end of said
needle hub with said passage about said catheter hub, said needle
and said cannula, an improvement comprising:
whereby said flashback plug is removable from said proximal end
of said needle hub;
wherein said distal end of said protector is of a construction
such that it engages with said proximal end of said needle hub with
said central passage in said protector in flow communication with
said central bore in said needle hub;
wherein said protector is of a construction such that an observer
can observe blood in said passage through said protector;
wherein said flashback plug is of a construction such that it engages
in said passage in said protector; and
whereby said flashback plug is replaceable in said proximal end
of said protector.
2. A peripheral IV catheter assembly as set forth in claim 1 wherein
said flashback plug is of a construction such that it engages in
said passage in said protector adjacent said proximal end of said
protector.
3. A peripheral IV catheter assembly as set forth in claim 1 wherein
said flashback plug is of a construction such that it engages in
said passage in said protector intermediate said proximal end of
said flashback and said distal end of said flashback plug.
IV catheter description
TECHNICAL FIELD
The present invention is concerned with peripheral IV catheter
assemblies. More specifically, the invention is concerned with an
improvement in a peripheral IV catheter assembly which allows the
flashback chamber to be significantly extended in length.
BACKGROUND ART
During normal insertion of an IV (intravenous) catheter, positive
indication of entry into a vein is shown by blood entering the normally
transparent needle hub through the needle. So long as the needle
and catheter are in the vein the chamber will continue to fill with
blood. If the needle and catheter are pushed in too far, thereby
puncturing the distal side of the vein wall and not remaining in
the vein lumen, the blood will stop filling the flashback chamber
(bore) of the needle hub.
In some medical situations an anesthesiologist will wish to use
a 16 gauge or larger catheter. In this case, the large needle size
allows blood to fill the flashback chamber so quickly that it is
difficult to determine whether the needle is in the vein lumen or
has passed through the distal vein wall. Normal practice is to add
a syringe to the flashback chamber to provide for extra volume.
This is costly and requires the procurement and storing of extra
parts. In some cases the syringe plunger is removed making the larger
flashback chamber essentially an open reservoir to the air. This
can increase the chance of infection.
DISCLOSURE OF INVENTION
The present invention is directed to solving one or more of the
problems as set forth above.
In accordance with an embodiment of the present invention an improvement
is set forth in a peripheral IV catheter assembly which comprises
a longitudinally extending needle hub having a proximal end, a distal
end and a central bore defining a flashback chamber, the needle
hub being of a construction such that an observer can observe blood
in the flashback chamber through the needle hub. A needle is held
by the central bore of the needle hub adjacent the distal end of
the needle hub and extends longitudinally therefrom. A catheter
hub having a proximal end, a distal end and a central bore fits
about the needle and has its proximal end held by the distal end
of the needle hub. A cannula having a proximal end, a distal end
and a central bore fits about the needle with the proximal end of
the cannula engaged with the distal end of the catheter hub. A flashback
plug having a proximal end and a distal end has its distal end adapted
to engage with the proximal end of the needle hub in blocking relation
to the bore of the needle hub. A protector has a proximal end, a
distal end and a central passage, the proximal end being adapted
to engage with the distal end of the needle hub with the passage
about the catheter hub, the needle and the cannula. An improvement
of the invention comprises a situation wherein the distal end of
the protector is adapted to engage with the proximal end of the
needle hub with the central passage in flow communication with the
central bore of the needle hub; wherein the protector is of a construction
such that an observer can observe blood in the passage through the
protector; and wherein the flashback plug is adapted to engage the
passage adjacent the proximal end of the protector.
The protector is a part which is normally used to protect the catheter
and needle from contamination by being touched. Normally protectors
are simply thrown away. In accordance with the present invention
the dimensions of the narrow end of the protector are made the same
as those of the front end of the flashback plug. As a result, the
narrow end of the protector can be inserted into the rear of the
flashback chamber of the needle hub, with a leak tight fit. This
extends the flashback chamber to a size equally that of the needle
hub plus that of the protector. The flashback plug also has a second
fitment which matches the internal fitment of the large end of the
protector. As a result, the flashback plug can be utilized to close
off the large end of the protector. No extra parts, such as a syringe,
are needed by an anesthesiologist using such a peripheral IV catheter
assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the figures
of the drawings wherein like numbers denote like parts throughout
and wherein:
FIG. 1 illustrates, in side view, a peripheral IV catheter assembly
in accordance with an embodiment of the present invention wherein
the protector portion thereof is utilized as a protector;
FIG. 2 illustrates, in side view, the embodiment as in FIG. 1 but
wherein the protector is utilized as a flashback chamber extender;
FIG. 3 illustrates, in side section view, the needle hub portion
and the needle portion of an embodiment as illustrated in FIGS.
1 and 2;
FIG. 4 illustrates, in side view, partially in section, the catheter
hub portion and cannula of an embodiment as illustrated in FIGS.
1 and 2;
FIG. 5 illustrates, in side sectional view, a flashback plug useful
in an embodiment as illustrated in FIGS. 1 and 2; and
FIG. 6 illustrates, in side sectional view, a protector useful
in an embodiment in accordance with FIGS. 1 and 2.
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is concerned with a peripheral IV catheter
assembly 10 illustrated in different modes of use in FIGS. 1 and
2. The peripheral IV catheter assembly 10 comprises a longitudinally
extending needle hub 12 having a proximal end 14 a distal end 16
and a central bore 18 which defines a flashback chamber 20. The
needle hub 12 is of a construction sufficient so that an observer
can observe blood in the flashback chamber 20 through the needle
hub 12. This can be accomplished by simply making the needle hub
12 out of a clear or transparent plastic material. Alternatively,
a translucent material can be utilized. Also alternatively, the
needle hub 12 can be made of an opaque material but an appropriate
transparent or translucent sealed window can be present. The needle
hub 12 is shown in best detail in FIG. 3. A needle 22 is held by
the central bore 18 adjacent the distal end 16 of the needle hub
12. The needle extends longitudinally from the distal end 16 of
the needle hub 12.
A catheter hub 24 seen in greatest detail in FIG. 4 has a proximal
end 26 and a distal end 28. A central bore 30 extends the length
of the catheter hub 24. The catheter hub 24 fits about the needle
22 and has its proximal end 26 held by the distal end 16 of the
needle hub 12. Generally a tapered fitment is utilized as shown
in FIG. 3 at the distal end 16 of the needle hub 12. The tapered
fitment at 16 forms a general mating sealing fit with the central
bore 30 of the catheter hub 24 adjacent the proximal end 26 thereof.
A cannula 32 also seen best in FIG. 4 has a proximal end 34
a distal end 36 and a central bore 38. The cannula 32 fits about
the needle 22 with the proximal end 34 of the cannula 32 being engaged
with the distal end 28 of the catheter hub 24. In the particular
embodiment illustrated the proximal end 34 of the cannula 32 fits
within the bore 30 of the catheter hub 24 at the distal end 28 thereof.
A flashback plug 40 (see FIGS. 1 2 and 5) is provided having a
proximal end 42 and a distal end 44. The distal end 44 of the flashback
plug 40 is adapted to engage with the proximal end 14 of the needle
hub 12 in blocking relation to the bore 18 of the needle hub 12.
Generally this blocking is accomplished by providing an appropriate
tapered fitment at the distal end 44 of the flashback plug 40 which
fits against a mating fitment within the bore 18 adjacent the proximal
end 14 of the needle hub 12.
A protector 46 (illustrated most clearly in FIG. 6) has a proximal
end 48 a distal end 50 and a central passage 52. The proximal end
48 of the protector 46 is adapted to engage with the distal end
16 of the needle hub 12 with the passage 52 about the catheter hub
24 the needle 22 and the cannula 32.
The configuration in which the peripheral IV catheter assembly
10 would normally be shipped is illustrated in FIG. 1. The protector
46 completely covers both the needle 22 and the cannula 32. In accordance
with the present invention certain improvements are set forth which
will be described in following and which allow the peripheral IV
catheter assembly 10 to be used in the configuration shown in FIG.
2.
In accordance with the present invention the distal end 50 of the
protector 46 is adapted to engage with the proximal end 14 of the
needle hub 12 with the central passage 52 in the protector 46 in
flow communication with the central bore 18 in the needle hub 12.
Further, the protector 46 is of a construction such that an observer
can observe blood in the passage 52 through the protector 46. For
example, it can be transparent, translucent, or have a transparent
window, or the like. This allows the protector 46 to be attached
so that the passage 52 serve as a continuation of the flashback
chamber 20. Since the protector 46 is of a construction such that
an observer can observe blood in the passage 50 through the protector
46 the observer can see whether blood is flowing even when using
a relatively large gauge needle.
Also in accordance with the present invention the flashback plug
40 is adapted, generally intermediate its proximal end 42 and its
distal end 44 to engage in the passage 52 in the protector 46
generally adjacent the proximal end 48 of the protector 46. This
provides a capping off of the combination flashback chamber 20 and
passageway 52 so as to protect against contamination and/or infection.
The flashback plug 40 can be adapted to engage in the passage 52
by, for example, providing a fitment portion 56 thereon, generally
of a tapered nature, and generally sufficient to seal against the
interior of the passage 52.
INDUSTRIAL APPLICABILITY
The present invention provides a peripheral IV catheter assembly
10 in which the flashback chamber 20 can be extended by the length
of the central passageway 52 to aid medical personnel in observing
whether the needle 22 is properly placed within the lumen of a vein.
Other aspects, objective and advantages of this invention can be
obtained from a study of the drawings, the disclosure and the appended
claims.
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