CROSS-REFERENCE TO THE RELATED APPLICATION
This application claims priority from Indian Patent Application No. 1225/KOL/2012
dated October 23, 2012, the entire disclosure of which is incorporated herein by
reference.
FIELD OF THE INVENTION
The present invention relates to a needle safety assembly, in particular for a
disposable medical device, comprising a needle and a protective cover for the
needle, wherein the needle is attached to a needle hub which can be moved
relative to the protective cover between a position of use in which at least the tip
of the needle is outside of the protective cover, and a retracted position in which
the needle is fully received in the protective cover.
BACKGROUND OF THE INVENTION
Healthcare workers are increasingly at risk of disease transmission, and nurses
perform the majority of invasive hypodermic procedures, such as injecting
medicine, collecting blood and inserting indwelling intravenous (I.V.) catheters.
Nurses and other healthcare personnel are routinely injured by the exposed,
sharp lancet of the needle after use on a patient. The critical time where a
percutaneous injury can occur is from the moment the needle is withdrawn from
the patient, or I.V. port, to the time the contaminated needle is safely discarded.
Prior to the proliferation of HIV and serum hepatitis, a needle stick injury was
considered a routine part of providing patient care. A needle stick injury now
carries a life-threatening consequence and healthcare workers must live with this
terror on a daily basis. Hence, there is a requirement for a low-cost safety needle
protector apparatus with a universal application which shall prevent accidental
contact of a medical professional or any other person with the sharp tip of the
needle after use of the disposable medical device and thus prevent possible
transmission of an infectious disease such as hepatitis, HIV, etc.
It is an object of the present invention to provide a needle safety assembly which
provides reliable protection against accidental pricking by a hypodermic needle
and which is easy and inexpensive to manufacture.
This object is satisfied by a needle safety assembly comprising a needle and a
protective cover for the needle , wherein the needle is attached to a needle hub
which has wings provided on opposite sides of the needle hub and which can be
moved relative to the protective cover from a position of use in which at least the
tip of the needle is outside of the protective cover into a retracted position in
which the needle is fully received in the protective cover, wherein the protective
cover is of generally tubular shape and defines two opposite axial slots which
extend from a distal end of the protective cover towards a tubular base portion of
the protective cover, wherein the slots are adapted to receive the wings when the
needle hub moves into the protective cover , and wherein the needle safety
assembly further comprises a locking mechanism adapted to secure the needle
hub inside the protective cover when the needle hub is in the retracted position.
SUMMARY OF THE INVENTION
A needle safety assembly of the invention comprises a needle and a protective
cover for the needle, wherein the needle is attached to a needle hub which has
wings provided on opposite sides of the needle hub and which can be moved
relative to the protective cover from a position of use in which at least the tip of the
needle is outside of the protective cover into a retracted position in which the
needle is fully received in the protective cover. The protective cover is of generally
tubular shape and defines two opposite axial slots which extend from a distal end
of the protective cover towards a tubular base portion of the protective cover,
wherein the axial slots are adapted to receive the wings when the needle hub
moves into the protective cover, and wherein the needle safety assembly further
comprises a locking mechanism adapted to secure the needle hub inside the
protective cover when the needle hub is in the retracted position.
In other words, the invention proposes a needle safety assembly which locks the
needle safely in the protective cover by an interlocking arrangement. The locking
mechanism effectively prevents the needle from inadvertently protruding out of the
protective cover. Thereby protection against accidental pricking by the needle is
greatly increased. Consequently, the needle safety assembly of the invention
ensures a safe disposal of the needle after its use.
It is to be noted that in the context of this invention the term "needle" comprises
any object having a sharp tip which can cause a percutaneous injury. Specifically,
in this context the term "needle" is understood to not only refer to a needle in the
literal sense but also to a blade which has a sharp tip.
Disposable medical devices in which the needle safety assembly can be used
include, for example, devices which are used to collect blood from a patient or a
donor or to give fluids to a patient, such as blood collection sets (e.g. PSV sets
with luer adapters), blood collection bag needles, scalp vein sets, and fistula
needles.
According to a preferred embodiment, the locking mechanism comprises at least
one pair of first and second locking means engaging with each other when the
needle hub is in the retracted position, wherein the first locking means is provided
on the needle hub and the second locking means is provided on the protective
cover.
In the case of more than one pair of first and second locking means, at least one
pair of first and second locking means may be arranged on a first side of the
needle safety assembly, while at least another pair of first and second locking
means may be arranged on a second side of the needle safety assembly opposite
from the first side, when the needle hub is in the retracted position. Alternatively, it
is also possible to have only one first locking means and more than one second
locking means, e.g. two opposite second locking means, or vice versa.
The needle safety assembly is particularly inexpensive to manufacture, if the first
locking means is formed integrally with the needle hub and/or the second locking
means is formed integrally with the protective cover.
Preferably, the first locking means defines a surface facing the needle tip, wherein
at least a portion of the surface extends in a plane generally perpendicular to the
needle. This makes a particularly effective interaction between the first and
second locking means possible.
According to a preferred embodiment, the first locking means comprises a
protrusion protruding from the needle hub.
For example, the first locking means may have a generally nose-like or ramp-like
shape, with its radial dimension increasing towards the tip of the needle.
In order to facilitate the movement of the needle hub into an interior passage of
the protective cover, the first locking means may be formed such that a radial
dimension of the locking means can be reduced against a restoring force. For
example, the first locking means may comprise a material having elastic
properties.
The first locking means may be arranged in the region of a proximal end of the
needle hub. This arrangement is particularly advantageous in the case of winged
needle hub.
According to a further embodiment, the second locking means is provided on the
tubular base portion of the protective cover.
The second locking means may comprise an opening in the protective cover,
which is adapted to receive the first locking means, e.g. a protrusion protruding
from the needle hub, when the needle hub is in the retracted position, thereby
interlocking the needle hub and the protective cover.
Additionally or alternatively, the second locking means may comprise a locking
tongue extending towards a proximal end of the protective cover and adapted to
engage with the first locking means, when the needle hub is in the retracted
position.
Preferably, the locking tongue extends towards the interior of the protective cover.
It may have resilient properties such that it can be pushed outwards by the first
locking means as the needle hub is moved towards its retracted position, and
snap back behind the first locking means once the needle hub has adopted its
retracted position. This is particularly advantageous if the first locking means does
not have elastic properties. Alternatively, the locking tongue may be rigid if the first
locking means comprises an elastic material.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
A preferred embodiment of the invention is described in the following description
and in the accompanying drawings, wherein:
Fig. 1 shows different views of a disposable medical device comprising a
needle safety assembly of the invention, with a needle hub in a
retracted position
Fig. 2 shows different views of a needle hub of the needle safety assembly
shown in Fig. 1;
Fig. 3 shows different views of a protective cover of the needle safety
assembly shown in Fig. 1.
DETAILED DESCRIPTION OF THE INVENTION:
Fig. 1 shows a disposable medical device, for example a blood collection kit or a
fistula needle kit, comprising a hypodermic needle 12 and a needle safety
assembly 10 to prevent accidental contact of a medical professional or any other
person with the sharp tip 14 of the needle 12 after use of the disposable medical
device.
In this context, the end of the needle 12 having the sharp tip 14 is denoted the
distal end, whereas the opposite end of the needle is denoted the proximal end.
Likewise the orientation of parts of other structural elements facing towards the
needle tip 14 will be referred to as distal, whereas the orientation of parts of these
structural elements facing in the opposite direction will be referred to as proximal.
The needle 12 extends in an axial direction, thereby defining an axial direction for
the needle safety assembly 10. A direction perpendicular to the axial direction is
denoted as radial.
In the region of its proximal end the needle 12 is connected, for example glued, to
a needle hub 16. The needle hub 16 is a so-called winged needle hub 16 having a
tubular main body 18 and two wings 20 which extend in opposite radial directions
from the main body 18. The wings 20 can either be formed integrally with the main
body 18, or they can be separate elements that are attached to the main body 18.
One end of a PVC tube 22 is attached, for example glued, to a proximal end
portion of the needle hub 16. The other end of the PVC tube 22 may, for example,
be connected to a blood collection bag (not shown) or any other component to
facilitate flow of fluid, such as medicine or blood, to or from a patient or donor. A
clamp 23 is slidably arranged on the PVC tube 22 and can be used to close off the
PVC tube 22.
As can be seen in Fig. 2, a locking protrusion 24 is arranged on a top side of the
main body 18 of the needle hub 16 in a proximal region thereof. The locking
protrusion 24 is integrally formed with the main body 18 and has a generally nose-
like or ramp-like shape, with its radial dimension increasing towards the tip 14 of
the needle 12. A distal face 25 of the locking protrusion 24 extends in a plane
generally perpendicular to the axial direction, i.e. in a radial plane.
The position of the locking protrusion 24 is rotated by an angle of generally 90°
about the needle axis with respect to the position of the wings 20, i.e. while the
wings 20 extend in a first plane, e.g. a horizontal plane, the locking protrusion 24
extends in a second plane that is oriented generally perpendicular to the first
plane, e.g. vertical.
As shown in Fig. 1, the needle safety assembly 10 further comprises a protective
cover 26 which is slidably arranged on the PVC tube 22 and which can be pushed
over the needle hub 16 and the needle 12 after the medical device has been
used.
The protective cover 26, shown in more detail in Fig. 3, is of generally tubular
shape, i.e. it has generally circular inner and outer cross-sections.
Two opposite axial slots 28 are formed in a wall of the protective cover 26 thereby
defining first and second opposite part tubular axial sections 30 of the protective
cover 26. The slots 28 extend from a distal end of the protective cover 26 towards
a tubular base portion 32 of the protective cover 26 which is formed in a proximal
end region of the protective cover 26.
The slots 28 are adapted to receive the wings 20 when the needle hub 16 moves
into the protective cover 26 thereby ensuring a correct rotational position of the
protective cover 26 relative to the needle hub 16.
The axial length of the slots 28 is greater than an axial distance between a
proximal face of the wings 20 and the needle tip 14. In other words, the axial
length of the slots 28 is selected such that the needle hub 16 and the needle 12
can be fully received inside the protective cover 26, in particular, with the needle
tip 14 being inside the protective cover 26 and thereby effectively precluded from
accidentally pricking someone.
Across a certain length, in the illustrated embodiment across almost half the axial
length of the protective cover 26, the slots 28 have a minimum width which can be
even smaller than the thickness of the wings 20.
Towards the distal end of the protective cover 26 the slots widen in order to
facilitate the insertion of the wings 20 when the protective cover 26 is pushed over
the needle hub 16. The slots 28 also widen towards the tubular base portion 32
and each comprise a significantly enlarged proximal region 34.
The enlarged proximal regions 34 of the slots 28 are defined by cut-outs in the
tubular wall of the protective cover 26 and result in tapered proximal end portions
36 of the axial sections 80, which pass into the tubular base portion 32 and which
have a thickness generally corresponding to the thickness of the tube wall. The
proximal end portions 36 have opposite flat inner surfaces 38 which pass into
corresponding flat surfaces inside the tubular base portion 32.
Elevated structures 40 are provided on the outer surfaces of the axial sections 30.
More specifically, the elevated structures 40 are in the form of arrows indicating
the direction in which the protective cover 26 is to be moved along the PVC tube
22 in order to cover the needle 14. Furthermore, the elevated structures 40 serve
to strengthen the axial sections 30 in the region of their tapered proximal end
portions 36.
The maximum inner diameter of the tubular protective cover 26 is smaller than the
maximum radial dimension of the needle hub 16 in the region of the peak of the
locking protrusion 24. Consequently, the axial sections 30 are spread apart when
the needle hub 16 moves into the protective cover 26, with the tapered proximal
end portions 36 providing a certain amount of flexibility and thereby facilitating the
spreading apart of the axial sections 30 and thus making the movement of the
needle hub 16 into the protective cover 26 easier.
It is to be noted that the transition from the minimum width regions of the slots 28
towards the enlarged proximal regions 34 of the slots 28 is continuous, more
specifically follows a gentle curve. As such, this transition does not serve to lock
the needle hub 16 in its retracted position inside the protective cover 26 and would
not prevent undesirable re-emerging of the covered needle tip 14.
Instead, two locking openings 42 are provided in the tubular wall of the base
portion 32 on opposite sides thereof. The position of the locking openings 42 is
rotated by generally 90° about the needle axis with respect to the slots. As such at
least one of the locking openings 42 is aligned with the locking protrusion 24 when
the wings 20 move along the slots 28.
The axial position of the locking openings 42 is adapted such that the locking
protrusion 24 engages one of the locking openings 42 when the needle 12 is fully
received in the protective cover 26 and the wings 20 abut against the base portion
32.
An arrangement of two locking openings 42 simplifies a correct locking of the
needle hub 16 inside the protective cover 26, since the protective cover 26 can be
rotated by 180° about the PVC tube 22 and still be correctly locked with the
needle hub 16. However, it is to be understood that a base portion 32 having only
one locking opening 42 would work as well, only in this case the person handling
the device would have to make sure that the single locking opening 42 is rotated
to the side of the locking protrusion 24 when the protective cover 26 is pushed
over the needle hub 16 in order to ensure a locking between the protective cover
26 and the needle hub 16.
In order to improve the desired locking function each locking opening 42 is
provided with a locking tongue 44 which protrudes from a distal side of the locking
opening 42 into the opening 42 and also into the interior of the base portion 32.
More specifically, the locking tongues 44 have a ramp-like shape with its radial
dimension increasing in a proximal direction and defining a proximal face 46 which
extends in a plane generally perpendicular to the axial direction. In the locked
state the distal face 25 of the locking protrusion 24 engages with the proximal face
46 of the locking tongue 44, thereby improving the locking effect and thus the
safety of the needle safety assembly 10.
In order to make it easier for the locking protrusion 24 to move past the locking
tongue 44 upon entering its locked position, the locking protrusion 24 may
comprise or be made of a material having certain elastic properties, such as a
plastic or silicon material. In fact, the entire needle hub 16 may be made of such a
material.
In comparison, the protective cover 26 may be made of a rather stiff plastic
material. Alternatively, the protective cover 26 may comprise or consist of a metal
material.
The function of the needle safety assembly 10 is as follows:
In the initial state of the medical device, e.g. prior to use of the medical device, the
needle hub 16 is outside the protective cover 26, with the protective cover 26
being moved along the PVC tube 22 away from the needle hub 16 as far as
desired.
A medical professional holds the wings 20 attached to the needle hub 16 and
punctures the skin of a patient with the needle 12 such that the needle 12 enters a
vein of patient. As the needle 12 enters the vein blood rushes into the needle 12
and through the main body 18 of the needle hub 16 into the PVC tube 22. The
blood is collected in a blood collection bag or a vacuum tube through a connection
to the other end of the PVC tube 22. Alternatively, the device may be used to give
fluids or medications to a patient.
After a required quantity of blood has been collected, the needle 12 is withdrawn
from the vein and the protective cover 26 is pushed over the needle hub 16 with
the wings 20 moving along the slots 28 until the locking protrusion 24 of the
needle hub 16 engages with the locking opening 42 and the locking tongue 44 of
the protective cover 26. The needle 12 is now fully received and locked inside the
protective cover 26 and the blood collection set can be safely disposed of.
Although this invention has been disclosed in the context of certain preferred
embodiments and examples, it will be understood by those skilled in the art that
the present invention can be constructed and utilized in a plethora of different
ways. It should be understood that many changes, modifications, variations and
other uses and applications will become apparent to those persons skilled in this
particular area of technology and to others after having been exposed to the
present specification and accompanying drawings. Any and all such change,
modifications, variations, and other uses and applications which do not depart
from the spirit and scope of the present invention are therefore covered by and
embraced within the present invention and the patent claims set forth herein-
below.
Reference Numerals
10 needle safety assembly
12 needle
14 needle tip
16 needle hub
18 main body
20 wing
22 PVC tube
23 clamp
24 locking protrusion
25 distal face
26 protective cover
28 slot
30 axial section
32 base portion
34 enlarged proximal region
36 end position
38 flat surface
40 elevated structure
42 locking opening
44 locking tongue
46 proximal face
WE CLAIM:
1. A needle safety assembly (10) comprising a needle (12) and a protective
cover (26) for the needle (12),
wherein the needle (12) is attached to a needle hub (16) which has
wings (20) provided on opposite sides of the needle hub (16) and which
can be moved relative to the protective cover (26) from a position of use in
which at least the tip (14) of the needle (12) is outside of the protective
cover (26) into a retracted position in which the needle (12) is fully received
in the protective cover (26),
wherein the protective cover (26) is of generally tubular shape and
defines two opposite axial slots (28) which extend from a distal end of the
protective cover (26) towards a tubular base portion (32) of the protective
cover (26), wherein the slots (28) are adapted to receive the wings (20)
when the needle hub (16) moves into the protective cover (26), and
wherein the needle safety assembly (16) further comprises a locking
mechanism adapted to secure the needle hub (16) inside the protective
cover (26) when the needle hub (16) is in the retracted position.
2. A needle safety assembly (10) in accordance with claim 1,
characterized in that
the locking mechanism comprises at least one pair of first and second
locking means (24, 42, 44) engaging with each other when the needle hub
(16) is in the retracted position, wherein the first locking means (24) is
provided on the needle hub (16) and the second locking means (42, 44) is
provided on the protective cover (26).
3. A needle safety assembly (10) in accordance with claim 2,
characterized in that
a position of the first locking means (24) on the needle hub (16) is rotated
by an angle of generally 90° about the needle axis with respect to the
position of the wings.
4. A needle safety assembly (10) in accordance with claim 2 or 3,
characterized in that
the first locking means (24) is formed integrally with the needle hub (16)
and/or the second locking means (42, 44) is formed integrally with the
protective cover (26).
5. A needle safety assembly (10) in accordance with any one of claims 2 to 4,
characterized in that
the first locking means (24) defines a surface (25) facing the needle tip
(14), wherein at least a portion of the surface (25) extends in a plane
generally perpendicular to the needle (12).
6. A needle safety assembly (10) in accordance with any one of claims 2 to 5,
characterized in that
the first locking means comprises a protrusion (24) protruding from the
needle hub (16).
7. A needle safety assembly (10) in accordance with any one of claims 2 to 6,
characterized in that
the first locking means (24) has a generally nose-like or ramp-like shape,
with its radial dimension increasing towards the tip (14) of the needle (12).
8. A needle safety assembly (10) in accordance with any one of claims 2 to 7,
characterized in that
the first locking means (24) is formed such that a radial dimension of the
first locking means (24) an be reduced against a restoring force.
9. A needle safety assembly (10) in accordance with any one of claims 2 to 8,
characterized in that
the first locking means (24) comprises a material having elastic properties.
10. A needle safety assembly (10) in accordance with any one of claims 2 to 9,
characterized in that
the first locking means (24) is arranged in the region of a proximal end of
the needle hub (16).
11. A needle safety assembly (10) in accordance with any one of claims 2 to
10, characterized in that
the second locking means (42, 44) is provided on the tubular base portion
(32) of the protective cover (26).
12. A needle safety assembly (10) in accordance with any one of claims 2 to
H.characterized in that
the second locking means comprises an opening (42) in the protective
cover (26), which is adapted to receive the first locking means (24) when
the needle hub (16) is in the retracted position.
13. A needle safety assembly (10) in accordance with any one of claims 2 to
12, characterized in that
the second locking means comprises a locking tongue (44) extending
towards a proximal end of the protective cover (26) and adapted to engage
with the first locking means (24) when the needle hub (16) is in the
retracted position.
14. A needle safety assembly (10) in accordance with claim 13,
characterized in that
the locking tongue (48) extends towards the interior of the protective cover
(26) and defines a proximal surface (46) which extends in a generally radial
plane.