TECHNICAL FIELD
The present invention relates to intravenous cannula with tip protector assembly, and,
more particularly to safety intravenous cannula having embodiment for protection against
any kind of the accidental injury due to the sticking of sharp tip of the needle.
BACKGROUND OF THE INVENTION
IV catheters are primarily used to infuse fluids, sometimes containing medications,
directly into patient’s vascular system or to withdraw blood from a patient. A hand held
placement device that includes a sharp tip needle is used to insert the catheter into a
patient’s vein. Such a device generally consists of hollow-bore needle and an over-theneedle plastic/silicon or like materials tubing used to access the lumen of a blood vessel
of a patient.
The catheter is inserted at a shallow angle through the patient’s skin into a peripheral
blood vessel by a health worker using the hand held placement device. The needle is then
withdrawn leaving the catheter in the place either for direct hook up for transfusion of
fluid or for the later use.
Once proper placement is confirmed the health worker applies pressure to the blood
vessel by pressing down on the patient’s skin near the tip of the needle and catheter.
During this process of placing the IV catheter in the vascular system of the patient, the
hollow- bore needle becomes blood contaminated and when the blood vessel is accessed,
the needle become blood filled.
In recent years, there has been great concern over the inadvertent injuries caused by the
“blood contaminated needles” to the medical professionals. This put the medical
professionals at great risk of being infected by the diseases which can be transmitted from
infected person to the injured person through the contaminated needle. Thus, it is
desirable to avoid contact of the patient’s body fluid with the medical professionals by
protecting the needle tip/bevel. This very danger to the safety of the medical
personnel/health care worker and the others has caused an impetus for the invention of a
safer intravenous Cannula in which the occurrence of such inadvertent injury due to
needle stick will be prevented.
Various attempts have been made since long back from time to time to prevent the needle
stick injuries through various kinds of assemblies of devices. However, some of them are
far expensive, complex due to their large numbers of components; some despite solving
the problems do cover large space. The prior art safety devices all exhibit one or more
drawbacks that have thereby far limited their usefulness and full acceptance by healthcare workers.
The invention disclosed in US4026287 provides for retraction of the used needle into a
cavity in a unitary, sturdy structure. However, it requires screwing the syringe plunger
into the back of the needle flange after use, to destroy a fragile seal around the flange and
then retract the needle. There are also chances of inadvertent introduction of fingertips
into the syringe barrel. Even the plunger could remain in place, held only by detents at
the rear of the barrel.
In US 4935012 A, a safety device comprises an elongated protective sleeve supported by
front and rear bearing members for sliding movement about a medical needle and its
associated support structure such as a support hub or barrel. The protective sleeve is
slidable in a stable manner from a first position with the pointed end of the needle safely
retracted within and shielded by the front bearing member to a second position with the
needle projecting through and beyond the front bearing member for normal use. After
use, the sleeve is slidable to a third position derailing the pointed needle end from the
front bearing member, and exposing a visual indicator to indicate that the needle has been
used. Closure flaps associated with the front bearing member, and thereby prevent
accidental or unauthorized needle reuse. Dent members interacting between the rear
bearing member and the needle support structure releasably lock the protective sleeve in
the various positions.
That the above said invention has its own limitations. The said invention provides
slidable sleeve for the protection of the needle which requires mechanical movement
whereas the present invention provide means for automatic protection. The working
mechanism for both of the invention are totally different. Inadvertent skipping of
mechanically moving the protection sleeve over the needle after the use may lead to the
needle stick injury. Further the slidable sleeve is not provided with any mechanism to
prevent the needle to come out of it if both are pulled in opposite directions. Also said
invention does not propose resilient material to successfully prevent the forward
movement of needle if push force is applied from the rear side of the needle. The present
invention overcomes the above mentioned limitations of the said invention by providing
automatic means for the protection against the needle stick injury. In the present
invention a tip protector assembly is used within the IV Cannula assembly which is
economical because of its simple yet highly workable structure and it successfully
protects the tip of the completely retracted needles ready for disposal.
SUMMARY OF THE INVENTION
Certain terminology is used herein for the convenience only and is not to be taken as a
limitation to the present invention. The term “distal” and “proximal” refer, respectively to
directions farther away and closer to from, respectively, to the person administering the
IV Cannula into the body of the patient. The terminology includes the word specifically
mentioned, derivatives thereof and words of similar import.
The present invention envisages an intravenous cannula with safety tip protector
assembly including a needle, an intravenous delivery catheter assembly removably
located coaxially over the needle such that the needle can be withdrawn from the
assembly after successful placement of the delivery end of the catheter tube in patient
vein. The present invention includes a safety tip protector assembly which is coaxially
and slidably arranged over the needle and removably attached to the proximal portion of
the catheter assembly and adopted to protectively cover the needle tip and having
mechanism for obstructing the needle tip from emerging out from distal end of safety tip
protector assembly once retracted and activating the said mechanism. The safety tip
protector assembly is also having mechanisms to engage a bulge present at the distal
portion of the needle near the bevel and thereby preventing the portion of the needle from
bulge till the tip from emerging out from the proximal end of the safety tip protector
assembly.
The said safety tip protector assembly is made up of non reactive metal preferably
stainless steel and comprises essentially of a retaining strip acting as a base and is present
with a needle through bore, a stem which is extension of one side of the base in distal
direction and further bending in a direction parallel to the base portion and is present with
a needle through bore upon said parallel portion in such a manner that the said needle
through bores and provides a passage for the needle. The needle through bore of the
retaining strip is having a profile larger than the principle profile of the needle but lesser
than the outer profile of the bulge/ dent present on the needle. The needle through bore
present at the said parallel portion is having a profile slightly larger than the outer profile
of the bulge and allows the bulge to pass through it. The stem is having length lesser than
the length of the needle portion between the bulge and the tip.
The safety tip protector assembly is also having a first arm and a second arm which are
extension of the sides of the base adjacent to the side attached with stem in distal
direction. A plurality of claws is at the distal ends of the first arm and the second arm
respectively and adapted to prevent the tip of the needle from emerging out of the distal
end of the tip protector assembly once retracted beyond the claws.
The safety tip protector assembly is also provided with means adapted to engage the
corresponding locking mean present on the inside surface of the catheter hub assembly
for removably holding the tip protector assembly within the catheter hub assembly.
The intravenous cannula with safety shield assembly further comprises of a protector
slidably arranged over the catheter tube, wherein the proximal portion of the said
protector is removably attached to an attachment site at the distal portion of wing body through a locking mechanism and hence protectively covering the bevel as well as the
catheter tube.
BRIEF DESCRIPTION OF DRAWINGS
The invention is illustrated by way of example and not by way of limitation in the figures
of the accompanying drawings in which like references indicate similar elements.
Fig. 1 is the top view of the complete assembly of the preferred embodiment according to
the present invention.
Fig. 2 is the complete assembly of the preferred embodiment in isometric view according
to the present invention.
Fig. 3 is the cross sectional view of the complete assembly of the preferred embodiment
according to the present invention.
Fig. 4 is the exploded view of the complete assembly of the preferred embodiment
according to the present invention.
Fig. 5 is the cross sectional view of the catheter assembly.
Fig. 6 is diagram of the needle.
Fig 7 is the diagram of the safety tip protector assembly.
Fig. 8 is the diagrammatic representation of the needle in retracted position, before the tip
of the needle passes the claws of the tip protector assembly.
Fig. 9 is the diagrammatic representation of the needle in retracted position after the tip
passed the claws of the tip protector assembly but before the tip protector assembly
securing the tip unlocked with the catheter assembly.
Fig 10 is the diagrammatic representation of the tip protector assembly securing the tip of
the needle and unlocked with the catheter assembly.
Fig. 11 is the diagrammatic representation of retracted needle hub assembly along with
the tip protector assembly securely covering the tip of the needle.
Fig. 12 is the isometric diagrammatic representation of retracted needle hub assembly
along with the tip protector assembly securely covering the tip of the needle.
DETAILED DESCRIPTION OF NATURE OF THE INVENTION
This description is not intended to be a detailed log of all the possible ways in which the
invention may be implemented, or all features that may be added to the instant invention.
For example, features illustrated with respect to a particular embodiment may be
incorporated into other embodiment, and features illustrated with respect to a particular
embodiment may be deleted from that embodiment. In addition, numerous variations and
additions to the various embodiment suggested herein will be apparent to those skilled in
the art in light of the present disclosure, which do not depart from the present invention.
Hence the following specifications are intended to illustrate some particular embodiment
and variations thereof.
In a preferred embodiment of the present invention as referred in figures 1 to 5, an
intravenous delivery catheter assembly (200) removably located coaxially over a needle
(100) such that the needle (100) can be withdrawn from the assembly (200) after
successful placement of the delivery end of the catheter tube (201) in patient vein. The
intravenous delivery catheter assembly (200) further comprises a catheter tube (201),
catheter holder (202), silicon tube (203), a wing body (204), wherein a safety tip
protector assembly (300) coaxially arranged over the needle (100) is removably arranged
inside the wing body (204) and is removably held with an inter locking mechanism
attained with engagement of a mean e.g. protruding rib pattern (205) present
circumferentially upon the inside surface of the wing body (204) with corresponding
means present upon body of the tip protector assembly (300) adapted to lock itself with
the rib pattern (205). The said interlocking mechanism may be disengaged with
application of force in the proximal direction. A cover (10) is slidably arranged over the
catheter tube (201) and is removably attached with the catheter hub/ wing body (204)
thereby protectively covering the bevel (101) as well as the catheter tube (201). The
assembly further includes an optional port (206) along with the port cap (207). A needle
hub assembly (400) is coaxially mounted over the proximal end of the needle (100) and
consist essentially of a needle hub (401), a flash back chamber (402) attached at the
proximal portion of the needle hub (401) and a luer lock (403) releasably attached at the
distal portion of the said flash back chamber (402). The distal end of the needle hub
assembly (400) is present with an elongation (404) adapted to push the safety tip
protector assembly (300) in distal direction from its proximal end.
As referred in figure 6, the needle (100) also has a bulge/dent (102) in the distal section
of the needle and more specifically near the tip/ bevel (101). The bulge (102) has an outer
profile, dimension of which is larger than maximum dimension of the principal outer
profile of the needle (100).

As referred in figures 7, the body of the tip protector assembly (300) of the present
invention is made of non reactive metal preferably but not limited to stainless steel. The
tip protector assembly (300) includes a retaining strip preferably a rectangular/ square
shape acting as a base (301) and is present with a needle through bore (302). A stem (303)
which is extension of one side of the base (301) in distal direction and further bending in
a direction parallel to the base portion and is present with a needle through bore (304)
upon said parallel portion (305) in such a manner that the needle through bores (302) and
(304) provides a passage (306) for the needle (100). The needle through bore (302) is
having a profile larger than the principle profile of the needle (100) but lesser than the
outer profile of the bulge/ dent (102) present on the needle (100). The needle through
bore (304) is having a profile slightly larger than the outer profile of the bulge (102) and
allows the bulge (102) to pass through it. The stem (303) is having length lesser than the
length of the needle portion between the bulge (102) and the tip (101). The tip protector
assembly (300) further comprises of first arm (307) and second arm (308) which are
extension of the sides of the base (301) adjacent to the side attached with stem (303) in distal direction. The first arm (307) of the tip protector assembly (300) is having a mean (309) adapted to
engage the corresponding locking mean e.g. rib pattern (205) present on inside surface of
the catheter hub assembly (200) for removably holding the tip protector assembly (300)
within the catheter hub assembly (200) in such a manner that it can be easily removed
merely by applying pressure outwardly thereto. The first arm (307) further bends at an
angle after the said mean (309) and further extended in the angular direction in such a
manner that the claw (310) present at the end of the first arm blocks the pathway of the
needle (100) along the direction to the axial said needle passage (306) and distal to the
needle through bore (304). The claw (310) is actually the extension of the first arm (307)
in which the end part of the arm is bent twice in such a manner that it forms claw like
structure so that once the tip (101) gets inside, the same get trapped inside and could not escape even after being pushed further in the distal direction. It is pertinent to mention that the first arm (307) is sufficiently long enough so as to block the needle pathway beyond the tip (101) of the needle (100) while the bulge (102) being engaged with the needle through bore (302); hence the path of the tip (101) of the needle (100) is blocked by the claw (310) in case the needle (100) is pushed in the distal direction. The second arm (308) similar to the first arm (307) also extends distally in axial direction and also having mean (311) adapted to get engaged with the rib (205) present inside the catheter
hub assembly (200). The position of the said mean (311) on the second arm (308) is just
opposite to the position of the mean (309) on the first arm (307) so that the both may be
simultaneously engaged with the rib (205) so as to provide efficient locking. The second
arm (308) is further bend after the said mean at a certain angle towards the axis
longitudinal to the needle passage (305). The second arm (308) is having sufficient length
that the claw (312) present on the second arm (307) blocks the needle path above the
claw (310) of the first arm (307).
The tip protector assembly (300) is such arranged that the movement of the needle (100)
in the proximal direction beyond the bulge (102) portion is stopped by the needle through
bore (302) present at the base portion (301) while a small portion of the needle preferably
portion distal to bevel (101) still being remaining beyond the distal side of the needle
through bore (304) present on the extended parallel portion (305) of the stem (303),
hence ultimately ensuring movement of the needle (100) along one trajectory only
passing through both afore said bores (302, 304).
While arranging the tip protector assembly (300) along the needle (100), proximal end of
the needle (100) slightly parting both arms (306,307) of the tip protector assembly (300)
is inserted from the through bore (304) present on the parallel portion (305) and further
travels from the through bore (302) present on the base (301). The needle hub assembly
(400) is then affixed with the proximal end of the needle (100). The slightly parted arms
(307,308) are thus stored with spring action restoring force. The needle (100) along with
the tip protector assembly (300) is then arranged with the catheter assembly (200) by
inserting the tip (101) of the needle from the rear portion of the catheter hub assembly
(200) and the needle (100) is pushed further in the distal direction so that the needle tip
(101) travels all along the catheter assembly and finally comes out at the end of the
catheter tube (201). The elongation (404) present at distal end of the needle hub assembly
(400) is long enough to push the tip protector assembly(300) to such an extent inside the
catheter hub assembly (200) so that the means (309, 311) present on the arms (307, 308)
get removably attached with the ribs (205) present in the catheter hub (200). Any further
movement of the projection (404) is stopped due to engagement of proximal end of the
wing body (204) with the distal end of the needle hub assembly upon which the
elongation (404) is mounted. The means (309,311) present on the arms (306,307) of the
tip protector assembly (300) get engaged with the ribs (205) present in the catheter hub
assembly (200) thereby removably locking the shield assembly within the catheter hub
assembly (200) in a release able manner.
To use the IV Cannula with the tip protector assembly (300) on patient, the needle cover
(10) is first removed while holding the cannula by the wing body (204) so that the needle
(100) along with the tip protector assembly (300) does not get pulled out from the
catheter hub (204). After, removal of the needle cover (10) the IV cannula is used over
the patient by a medical practitioner to puncture the vein of the patient. After successful
puncture of the vein by the tip (101) of the needle (101) and confirmed by the flow of
blood in the flash chamber (402), the needle hub assembly (400) is slowly pulled out
with one hand while holding the catheter hub assembly (200) securely in the place with
the second hand. The needle slowly travels backwards leaving catheter tube and tip (101)
passes firstly the wing body/catheter hub then passes the claw (312) of the second arm
(308) and then claw (310) of the first arm (307) and the needle (100) travels further in the
proximal direction till the bulge (102) get engaged with the needle through bore (302).
The moment the tip (101) passes the claws (312,310) of the arms (308,307) the restoring
force present in the arms (308,307) makes them move in transverse direction towards the
needle pathway and the claws (312,310) present on arms (308,307) get positioned so as to
block the movement of the needle (100) in the distal direction. Further pulling force
applied on the needle hub assembly (400) in the proximal direction pulls out the tip
protector assembly (300) out of the catheter hub assembly (200) whereby the tip (101) of
the needle gets secured by the tip protector assembly (300) without any risk or danger of
needle prick to the medical practitioner. The used needle with the tip protector assembly
(300) locked can then be safely disposed off. Figures 8 – 12 may be referred to.

We Claim:-
1. An intravenous cannula with a tip protector assembly comprising:
a needle;
an intravenous delivery catheter assembly (200) removably located coaxially over
the needle (100) in such a manner that the needle (100) can be withdrawn from the
assembly (200) after successful placement of the delivery end of a catheter tube
(201) in the patient vein;
characterized in that a tip protector assembly (300) is coaxially and moveably
arranged over the needle (100) and remove attached to the proximal portion of the
catheter assembly (200) and adapted to protectively cover a bevel/tip (101) and
having mechanism for obstructing bevel/tip (101) from emerging out of its distal
end once retracted and activate the said mechanism and also having another
mechanism to engage a bulge (102) present at the distal portion of the needle (100)
but proximally closer than bevel (102) and thereby preventing the portion of needle
(100) from bulge (102) till the bevel (101) from emerging out from the proximal
end of the tip protector assembly(300).
2. The intravenous cannula with tip protector assembly as claimed in claim 1, wherein
the tip protector assembly (300) is having a non reactive metallic body.
3. The intravenous cannula with tip protector assembly as claimed in claim 1 to 2,
wherein the tip protector assembly (300) further comprises:
a retaining strip acting as a base (301) and is present with a needle through bore
(302);
a stem (303) which is extension of one side of the base (301) in distal direction and
further bending in a direction parallel to the base portion and is present with a
needle through bore (304) upon said parallel portion (305) in such a manner that the
needle through bores (302) and (304) provides a passage (306) for the needle (100).
The needle through bore 302 is having a profile larger than the principle profile of
the needle but lesser than the outer profile of the bulge/ dent (102) present on the
needle (100). The needle through bore (304) is having a profile slightly larger than
the outer profile of the bulge (102) and allows the bulge (102) to pass through it.
The stem (303) is having length lesser than the length of the needle portion between
the bulge (102) and the tip (101);
a first arm (307) and a second arm (308) which are extension of the sides of the
base (301) adjacent to the side attached with stem (303) in distal direction;
a plurality of claws (310, 312) at the distal ends of the first arm (307) and the
second arm (308) respectively and adapted to prevent the tip (101) of the needle
(100) from emerging out of the distal end of the tip protector assembly (300) once
retracted beyond the claws (312, 310).
4. The intravenous cannula with tip protector assembly as claimed in claim 1 to 3,
wherein the arms (307, 308) of tip protector assembly (300) further comprises
means (309, 311) adapted to engage the corresponding mean (205) present inside
the catheter hub assembly (200) thereby providing secure but removable holding of
the tip protector assembly (300) within the catheter hub assembly (200).
5. The intravenous cannula with tip protector assembly as claimed in claim 1 to 4,
wherein the intravenous delivery catheter assembly (200) further comprises a
catheter tube (201), catheter holder (202), silicon tube (203), a wing body(204) is
coaxially and removably attached over the tip protector assembly (300) by the said
interlocking mechanism.
6. The intravenous cannula with tip protector assembly as claimed in claim 1 to 5,
further comprises of a needle hub assembly (400) coaxially mounted over the
needle and consist essentially of a needle hub (401) a flash back chamber (402)
attached at the proximal portion of the needle hub (401) and a luer lock (403)
releasably attached at the distal portion of the said flash back chamber (402),
wherein the distal portion of the needle hub assembly (400) has an elongation (404)
adapted to push the tip protector assembly inside the catheter assembly (200) till the
extent the means (309, 311) of tip protector assembly (300) get removably
interlocked with corresponding mean (205) present inside the catheter assembly
(200).
7. The.intravenous cannula with tip protector assembly as claimed in claim 1 to 6,
further comprises of a cover (10) slidably arranged over the catheter tube (201),
wherein the proximal portion of the said cover (10) is removably attached to an
attachment site at the distal portion of the wing body (204) through a locking
mechanism and hence protectively covering the bevel (101) as well as the catheter
tube (201).