Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
20~979~
Page 1
BACKGROUND OF THE INVENTION
This invention Is concerned wlth a protectlve device ~or a needle of a
syringel catheter or similar medical appliance for human or anlmal use.
SUMMARY OF THE INVENTION
The invention prov~des a protectiYe device for an elongate needle of the
kind described which has a base at one end and a point at an opposing
end, the device including a blocking surface and means which extends
from the base and which supports the blocking surface, the blocking
surface having a hole and being movable at least towards the base to
allow the needle to extend through the hole.
The dev~ce may be prov~ded so that the needle is aligned with the hole,
but not extending therethrough. The device is then ready for use. After
use the blocking surface is brought automaUcally or manually to a
position at which it opposes the needle point.
Alternativelythe device is provided with the blocking surface opposing the
26 needle point and the blocking surface ~s movable, preferably laterally,
relatively to the needle point to bring the hole and the needle point into
20~979~
Page 2
alignment, and thereby ready the device tor use.
The support means may take on any suitable torm and may comprlse one
or more strips of material, which may be resil~ently deformable, and which
extend trom the base to the blocking surface.
llle support means may alternatively include a tubular member within
which the needle is located with the blocking surface at one end of the
tubular member.
A disc may be located inside the tubular member and may have an
aperture through which the needle extends to maintain the needle point
out of register with the said hole.
16 llle tubular member may be made from a resiliently deformable and
medically acceptable material such as a rubber or plastics material, foam
rubber or the like, and preferably is transparent. A deformable ~iller
material such as sponge rubber may be inside the tubular mernber.
Sealing means may be engaged with the tubular member to keep the
needle sterile. The sealing rneans may be a dust cap, or a stopper which
~its into the hole, or the like.
The tubular member may include at least one de~ormable bellows
20S~79~
Pa~ 3
tormation which may be near the base ot the needle, or may Include a
plurality ot spaced bellows formatlons ot the same or dmerent slzes.
The dev~ce may include b~as~ng means whlch acts agalnst the support
means when the blocking sur~ace is moved towards the base and
thereafter acts to extend the support means automatically to its initial
posfflon.
The blocking surface may include a recessed format~on ~n the form of a
blind or dead-end passage which may oppose or which may be moved so
that it opposes the point of the needle and the hole may be formed
adjacent the recessed formation. Movement of the needle towards the
blocking surface thus causes the point to enter the dead-end passage.
The blocking surface is of a material which is sufficiently hard or thick to
prevent penetration of the blocking surface by the poTnt. The blocking
surface may include surfaces which diverge away from the hole so that
when the needle extends through the hole it is completely free of the
blocking surface. The recessed formation may surround the hole.
The support means preferably engages directly with the base or hub of
the needle bui may engage with a syringe or other instrument with which
the needle is used.
2~979~
Page 4
The blocking surtace may be moved laterally and twisted relatlvely to the
needle to bring the hole Into reglster with the polnt or, conversely, to
move the hole so that it is not al!gned with the polnt.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further described by way of examples witS~ reference to
the accompanying drawings in which:
0
Figures 1 to 7 are side views in cross section illustrating different
embodiments of the protective device of the invention, and
Figures 8 to 10 are side views in cross section respectively illustrating in
enlarged detail different possible forms of construction which can be
embodied in the protective device.
DESCRIPTION OF PREFERRED EMBODIMENTS
0
Figure 1 illustrates one end ot a known syringe 10 which includes a
plunger 12 which is adapted to expel fluid 14 of any appropriate kind
through a nozzle 16 formed by a spigot 18. A stainless steel injection
20~79~
Page 5
needle 20 w~th a base or hub 22 Is tr~cUonally engaged in a leakproo~
manner with the splgot 18 so tha~ the contents ol the syrlnge are, on
acUvation ot the plunger, expelled through a leadlng end or point 24 ot the
needle.
A protective device 26 is engaged with the syringe and comprises a
housing formed trom a clear plastics material which is slightly resiliently
deformable. The housing has a socket 28 with a nange 30 which engages
w~h an undercut tormation 32 on the socket.
The socket 28 includes two opposed extensions 34 or, alternatively, a
continuous flange 34. If manual force is exerted on the formation 34 then
the socket can be moved to the left relatively to the syringe. A coil spring
36 inside the socket acts between a right hand end of the socket and an
opposing end of the syringe.
The housing includes a tubular member 38 within which the needle 20 is
located. At one end the member has a blocking surface 40 with a blind or
dead end passage 42 and a hole 44 adjacent the passage 42. Under
normal conditions the needle 20 is aligned with the dead-end passage
with the point 24 at the mouth of the passage and if the device is moved
to the left relatively to the syringe, the point 24 is advanced into the
passage.
2~979~
Pa~e 6
When the syringe is to be used the member 38 Is detlected slighUy so that
the llole 44 Is allgned wlth the needle polnt. As an Inlectlon Is glven the
needle po~nt penetrates the skln o~ the reclplent. A r~actlon torce Is
generated on the outer side ot the blocking surface and this causes the
housing ~o move to the left relatively to the syr~nge, agalnst the bias ot the
spring 36.
When the needle is withdrawn the tubular member automatically moves
to the right under the action o~ the spring. The emerging needle is
therefore fully and automatically enc~osed by the tubular member and the
natural resilience of the tubular member re-aligns the needle point with
the dead-end passage. This minimizes the likelihood of any infection
being accidentally transferred via the needle.
Figure 2 shows a device with a housing 60 which has a socket 62 formed
with bellows 64 which have a natural resilience resulting from their shape
and material. When an injection is given and the member 38 is moved to
the left the bellows are compressed. When the needle is removed from
the recipient the bellows automatically expand and the tubular member 38
is moved to the right to enclose and protect the needle point.
Figure 3 illustrates a simplified device 65 which comprises a tubular
member 38 made from a resilient material such as latex rubber with a
20~79~
Page 7
plurality o~ spaced bellows format~ons 66. At one end the tubular member
engages directly with a hub 22 ot an InJectlon or catheter needle 20. The
point 24 o~ the needle l~es at the mouth o~ a dead-end passage 42 on a
blocking surtace 40 at an opposing end of the tubular member. A hole 44
S is tormed adjacent the passage.
When an injection is to be given the tubular member is pulled slightly in
the direction away trom the hub and is displaced laterally to align the
point 24 with the hole 44. As the needle enters the recipient the member
38 is axially compressed with the formaUons 66 taking up the movement.
When the needle is withdrawn the tormations 66 automatically extend the
member 38 and the needle is thereby retracted into the member 38 and
the point 24 is again aligned with the passage 42.
Figure 4 shows a device 68 which is similar to the device 65 but with
bellows tormations 66A, 66B, 66C and 66D which are progressively
smaller so that the member 38 has a tapered or conical appearance.
Figure ~ shows a device 70 with a single bellows formation 66E and with
the remainder of the tubular member 38 being of more or less constant
cross section. A removable dust cap 72 encloses the outer end of the
member 38 so that the needle 20 is kept in a sterile condition within the
member. This tubular member is easier to make than the members of
20S979~
Page 8
Figures 3 and 4. Instead of the dust cap a stopper can be plu~ged Into the
hole 44 to seal the Interlor ot the tubular member.
The devices ot Figures 3 to 5 include two components whlch are secured
to one another in any appropriate way, namely the member 38, and the
blocking surface which is made from a relatively hard plastics material
which the needle point does not readily penetrate. It is preterred to
engage the tubular member with the base of the needle but it is possible
to tix the member to a syringe or other device with which the needle is
used.
Figure 6 shows a device 74 with a tubular member 38 of regular cross
section made from a resiliently flexible material such as toam rubber. A
disc 76 is positioned inside the member and has an aperture 78 through
which the needle 20 passes. The disc keeps the point 24 aligned with a
dead-end passage 42 on the blocking surface 40. The member 38 can be
deflected to one side so that the hole 44 is aligned with the point 24 when
an injection is to be given.
The interior of the member 38 may optionally be filled with an easily
compressible material 80, such as low density foam rubber, to enhance
its resilience. Alternatively the resilience can be achieved from the foam
rubber 80 alone and the foam rubber can be protected by means of the
2~979 ~
Page 9
member 38 which can be made trom an impermeable material.
A disc, similar to the disc 76, can also be used wlth the embodlments ot
Fi~ures 3 to 5.
Figure 7 shows a device 82 which is made as a one-piece plastics
moulding. A ring 84 is engaged with the hub 22 of a needle 20 and at least
one strip of material 86 extends from the ring to a member 88 which
comprises a dead-end passage 42 and a blocking surface 40 with a hole
44 adjacent the passage 42.
The strip 86 aligns the passage 42 with the point 24. When an injection is
to be given the strip is deflected laterally so that ~he point 24 is aligned
with the hole 44. The member 88 is movable along the needle with the
strip 86 deflecting outwardly away from the needle as an injection is
given. Once the needle is withdrawn the strip 86 returns to its original
position under its own resilience and the needle point is withdrawn
through the hole 44 and is aligned with the passage 42.
The strip 86 or the member 38 is made from a resilient material so that the
needle point is automatically protected after an injection is given. This
need not necessarily be the case for the protective device can be made
from a material which has a low natural resilience. The onus then rests on
20~979~
Page 10
the user to cause it to extend so that the needle ~s brought to a protected
position with Its polnt opposing the blocklng sur~ace, atter an InJectlon
has ~een g~ven.
Figures 8, 9 and 10 illustrate in enlarged cross section dmerent torms ot
construction for the blocking surface 40. In Figure 8 the blocking sur~ace
is inclined to th~ axis of the needle and the hole 44 adiacent the dead-end
passage is defined by a short passage 90 of circular cross section. In
Figure 9 the blocking surface is also inclined to the needle but the hole
44 opens into a passage 90 of increasing cross section. In Figure 10 on
the other hand the hole 44 does not lead to a passage 90 of the kind
shom in Figures ~ and 9. The two latter constructions prevent the point
of the needle from inadvertently snagging on the blocking surface.
With the devices of Figures 1 to 7 the point of the needle is not initially
aligned with the hole, but rather with the dead-end passage. n Is possible,
particularly with the embodiments of Figures 3 to 5, to provide the device
with the needle point aligned with the hole 44, partly inside the passage
90, and ready for use. After an injection is given the blocking surface can
be moved manually so that the needle point opposes the dead-end
passage and is then protected. It has also been found that when the
needle is withdrawn the compressed bellows expand to such an extent
that the needle point is fully retracted from the passage 90 and the
2~S~795
Pa~e 11
resilience of the member then causes movement ot the block~ng sur~ace
so that the po~nt is aligned with the dead end passage, and Is protected.
A similar effect is achleved slmply by shaklng the syrlnge - the movement
extends the tubular member and the needle then moves ~nto allgnment
with the dead-end passage.
