Note: Descriptions are shown in the official language in which they were submitted.
WO 95/20419 ~ ? ~ ~ L ~ ~ PCTIL3S95J01221
This invention relates to a breathing apparatus
connection assembly for a tracheostomy tube assembly that
employs positive locking of the connection between a
connector head and a connector body.
Tracheostomy tubes are used to assist a patient to
breathe. The tube is inserted in a patient's throat
through a puncture wound below an obstruction. When in
place, the tube provides a direct connection between an
oxygen or air source and the trachea.
A com~n type of-_ tracheostomy tube is equipped with
inner and outer cannulae; the inner cannula fitting within
the outer cannula. The inner cannula is provided with a
connector body while the outer cannula is provided with a
connector- head. The connector body and connector head
interlock to secure the inner cannula within the outer
cannula. A breathing apparatus connector slides aver this
connection to provide a complete air circuit.
The inner cannula is removable if obstructed. When
the inner cannula is removed, the outer cannula maintains
the oxygen or air path to the trachea. To assist in its
removal, and to avoid discomfort to the patient, the
disposable cannula should be easily detached from the outer-
cannula. Ease in detachment is particularly important
where the patient is connected to a ventilator because it
is likely that the patient is unable to breathe on his own
while the changeover is accomplished.
Many tubes in the prior art employ manually clamping
WO 95120419 218 2 2 6 6 P~~S95/01221
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of the inner cannula to the outer cannula. Crandall, U.S.
Patent No. 4,009,720 employs a device with two clamps
having short, cantilevered actuator arms attached to hooks.
The clamps are connected to the disposable cannula and the
actuator arn~s are substantially in the same plane as the
connection point for the clamps. The clamp is operated by
pressing the cantilevered actuator arms, thereby causing
the hooks to rotate to an open position against the torque
from a flexible hinge. Once the disposable cannula is
properly inserted into the outer cannula, pressure is
released and the hooks secure the cannulae together. To
prevent breakage from an over-extension of the hinge, stops
are provided for the clamps. Similar devices are disclosed
in Crandall, et al., U.S. Patent No. 3,639,624, Crandall et
al., U.S. Patent No. 4,135,505, Eisele, U.S. Patent No.
5,067,496, and Abel, U.S. Patent No. 5,067,515.
Other tubes employ friction-fit locking devices. U.S.
Patent No. 4,052,990 to Dodgson discloses a typical tubing
adaptor that is assembled with an endotracheal tube such as
a tracheostomy tube. The device comprises a lt~lding having
a cup shaped body portion with an internal stem. The stem
has an outwardly flared lip. This lip is engaged by the
tube to provide a friction fit without a positive locking
connection. Consequently, this connector is subject to
accidental disconnections.
While these clays adequately secure the ~nnAr Hula
to the outer cannula, accidental disconnections have
occurred because the patient is capable of unfastening the
inner cannula while the tracheostomy tube is connected to
a ventilator or other breathing apparatus. It is desirable
for devices connecting tracheal tubes and breathing
apparatus or otherox~rgen or air sources be able to avoid
accidental disconnection, even when subjected to aggressive
WO 95/20419 2 l 8 2 ~ ~ 6 PCTfUS95J01221
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manipulation by an active patient. There is a need for a
locking system that prevents detachment of the cannulae,
while at the same time, allows easy detachment of the inner
cannula by the care giver.
The Invention
This invention relates to an improvement in
tracheostomy tube assemblies that employs inner and outer
cannulae linked by a locking device. The improvement is a
locking device for the inner and outer cannulae that
prevents the patient from accidentally separating the inner
cannula from the outer cannula when it is connected to a
breathing apparatus.
A tracheal tube, such as an outer cannula, with the
typical proximal and distal ends is provided with a
connector head circi.mmscribing its proximal end. The
connector head provides an attaching surface for linkage to
a readily detachable connector body. The connector body is
locked to the connector head via interlocking catches,
latch receiving surfaces, ribs and/or lips . A securing
component such as a breathing apparatus connector is fitted
over the interlocked connector body and connector head to
provide a positive locking device wherein the locked
connector and connector head are held together in a fixed
position through the positive pressure imposed on them by
the securing component.
The cormector body /connector head locking device
comprises an interlocking male and female assembly. The
connector body and connector head are locked together by
joined catch and a latch receiving surface. T'he catch is
located on either the connector head or connector body, and
. the latch receiving surface is located on the other of the
connector body or connector head, to form an interlocking
WO 9512019 PCTIUS95/01221
2182266
a
assembly. Either the connector bady or the connector head
is provided with a rib and/or a lip and whichever of the.
connector body or connector head that does not have the rib
and/or lip is provided with at least one flexible
cantilevered member capable of mounting the rib or lip and ,
expanding the same sufficiently that the connector head and -
the connector body can be separated.
To facilitate disconnection, the ribs and lips have
camping surfaces such that when these elements are twisted
or pulled along a vertical- axis, they slide under the
flexible cantilevered member(s), causing the members) to
flex by riding on the camped surface(s). Once the. members
have flexed, the interlocking catches and latch receiving -
surfaces are disengaged and no longer interlock by pulling
the connector body from the connector head or vice versa.
The connector body and connector head are easily separated.
To ensure against accidental disconnection, a securing
component such as a breathing apparatus connector is fitted
over the connector body and connector head to frictionally
engage and lock the rib or lip of the connector body by
providing preseure to hold the cantilevered members in a
fixed relationship to the rib or lip, thereby providing a
positive lock.
Figure 1 is a perspective side view of a tracheostomy
device embracing the connection device of the invention.
Figure 2 comprises Figures 2A, 2B and-2C, in which 2A ,-
is a perspective side view of the connection device of the
invention, 2B is a perspective side view of the securing ,
member and 2C is perspective side view of the locked
WO 95/20419 218 2 2 6 ~ PCT~595J01221
connector body and connector head assembly. Figures 2B and
2C represent an exploded view of Figure 2A.
Figure 3 comprises Figures 3A, 3B and 3C, in which the
connector assembly of Figure 2C is shown turned for
5 detachment, in the case of Figure 3A, and exploded in the
case of Figures 3B and 3C, to show the component parts of-
the.connector body and connector head.
Figure 4 comprises Figures 4A, 4B and 4C which show
cross-sectional views along lines 4A-4A of Figure 2A, lines
4B-9:B of Figure 2C and lines 4C-4C of Figure 3A.
Figure 5 comprises Figures 5A, 5B and 5C, in which
Figure 5A is a perspective side view of an alternative
connector assembly, Figure 5B is the same view except that
it contains a cutaway section showing a locking mechanism
and the related unlocking ramped lip, and Figure 5C is a
cross sectional view along line 5C-5C of Figure SB.
Figure 6 comprises Figures 6A and 6B, in which Figure
6A is a perspective, partial exploded view and Figure 6B is
a side view of the connection device of the invention.
Reference is made to- the drawings as an aid to
understanding the details of the invention. T'he numbers
used in the drawings are consistently applied and where the
same number is employed in more.than one figure, it has the
same meaning. Figure 1 shows the relationship of a locking
device 10 of the invention to a typical tracheostomy tube
assembly. An outer cannula 21 is provided with a connector
. head 11 circumscribing its end. An inner cannula (not
shown) is provided with a connector body 12 circumscribing
WO 95/20-119 PCT/US95/01221
2182266
6
its end. These components are locked together via locking
device 10. Not shown in-Figure 1 or the other drawings is
the conventional tubing connecting the breathing apparatus
mechanism to the connector head 11 and connector body 12.
Such breathing apparatus tubing is generally made of a
flexible plastic such as plasticized polyvinylchloride.
The tubing is mechanically fitted to breathing apparatus
connector 13. It is desirable that the tubing's inside
diameter is not less than the largest outer diameter
dimension of the connector body 12. Locking device 10 has
an open passageway 19 that openly connects with the tubular
opPntng of cannulae and the tubular opening of the
breathing apparatus tubing (not shown) that is mechanically
fitted to the breathing apparatus connector 13. Open
passageway 19-defines a portion of the air passageway to
the patient's trachea.
Figure 2 focuses on the locking device 10. Locking
device l0 is composed of three main components: connector
head 11, connector body 12 and rib engagement or breathing
apparatus connector 13. Locking device 10 is connected to
outer cannula 21 of the tracheostomy tube via connector
head 11 and inner cannula via connector body 12 and
connected to the breathing apparatus via attachment of the
breathing apparatus tubing (not shown) to the junction of
the two. Connector head 11 has an attachable and
detachable relationship with connector body 12. When
connector head 11 and connector body 12- are attached, the
inner cannula is situated within the outer cannula 21 and
a rib engagement or breathing apparatus connector 13,
functioning as a collar, slides over the attached connector
head 11 and connector body 12 to apply a positive pressure:
on their juncture, to assure that they are not separated.
This design ensures security against accidental
disconnections while providing minimum discomfort to the
WO 95120419 ~ ~ 8 2 2 6 6 PCT~595101221
7
patient when the breathing apparatus connector 13 is
removed and the connector body 12 is detached from the
connector head 11.
As depicted in Figures 2 and 3, connector head 11 and
connector body 12 are cylindrical and when they are
connected, a part of each is concentrically inter-aligned.
Connector body 12 has a cylindrical coupling surface or
mating surface 14 and an exposed cylindrical base 16. Base
16 has a larger diameter than coupling surface 14 and the
juncture of the two forms seating surface 15. Seating
surface 15 circumscribes both exposed base 16 and coupling
surface 14.
T'he shapes of the connector body 12 and connector head
11 may be reversed, e.g., the cylindrical coupling surface
14 and seating surface 15 could be part of connector head
11 and connector head 11 could adopt the shape and function
of the remainder of connector body 12 except that it would
still be attached to the outer- cannula 21, whereas
connector body 12 could adopt the shape and function of
connector head 11 except that it would still be connected
to the inner cannula 20.
As shown in Figures 1-4, connector body 12 contains
one or ire ribs 17. However, if the functions of
connector body 12 and connector head 11 were reversed, then
each rib 17 would be on connector head 11. The description
set. forth below is equally applicable to a device wherein
the connector head 11 is provided with one or more ribs 17.
~ One or-more ribs 17 extend from seating surface 15 and
mating surface 14. Each rib 17 in this embodiment is
generally mushroom-shaped, in this case an inverted
mushroom shape, with a sloping stem41 connected to seating
WO 95120419 218 2 2 6 b PCT~S95/01221
8
surface 15, and sidewalls 42 that mainly connect to surface
14, and a sloping cap 32, extending from'stem 41, mated to
sidewalls 53 extending from surface 14. -The slopes of stem ,
41 and cap 32 are inthe same direction andtheir
variations in thiclazess, detP~~ned along imaginary lines ,
defined as normal to seating surface 15, are substantially
the same except where cap 32 extends beyond the dimensions
of stem 41. The distance from the top of stem 41 and cap
32 to the mating surface 14 varies depending on-the point
of measurement so as to-form the slope. However, to ensure
proper connection to the connector head 11, it is preferred
that each rib 17 be no thicker than the distance across
seating surface 15. _
Sidewalls 42 and 53 are-straight or sloping depending
on a number of factors. If sidewalls 42 and 53 are
intended to provide part of the ramping surface of stem 41
and cap 32, then it is desirable that they have a sloping
surface. But if all of the camping will be pravidedby the
surfaces of stem 41 and cap 32, then sidewalls 42 and 53
may be straight. Preferably, sidewalls 42 and 53 taper
away from stem 41 and cap 32. The overall shape ofrib 17
may vary consistent with need for a secure connection
between connector body 12 and connector head 11. By way of
illustration but not limitation, oblong, triangular and fin
shaped ribs 17 are contemplated.
Associated with rib 17 and part of cap 32 are two
catches 36. catches 36 appear as the overhang portion of
cap 32 and function as hooks. Each catch 36 has a
thiclmess in keeping with the sloping characteristics of
cap 32 and sidewalls 53. Where the slope of cap 32 is in
one direction, then one catch 36 will be higher than the
other catch 36. The lower catch 36 will be part of the
camping surface used for detachment. -
~'O 95I204I9 213 2 2 5 6 PCT~S95101221
9
As shown in Figures 3 and 4, ribs 17 contain sloping
surfaces, illustrated in this case as stem 41. Cap 32 is
equally sloping. These sloping surfaces provide a ramping
surface by which the connector head 11, in this embodiment,
can be detached from-connection to connector body 12.
In order to latch connector head 11 to connector body
12, there may be provided on connector-head 12 one or more
latch receiver surfaces 29 within one or more cut-out
portions 39 of a sleeve 24. Sleeve 24 emerges from base
coupling collar 26. Base coupling collar 26 is bonded,
preferably adhesively, to cannula 21. Cut-out portion 39
has the general shape of ribs 17 so that catch 36 may
comfortably fit within latch receiving surfaces 29. Latch
receiving surfaces 29 form part of the sidewall of sleeve
24. Catch 36 and latch receiving surface 29 form a latch
30 by which connector head 11 and connector body 12 are
locked together.
Sleeve24 is made of a pliable material such as
polyester, polycarbonate and polysulfone and expands when
twisted so that its inner surface slides over rib 17. This
cantilevered action separates catch 36 from latch receiving
surfaces 29.
A special feature of rib 17 is the sloping surface
which allows ramping of the flexible cantilevered sleeve 24
up -and on the uppermost surface of rib 17. T~lhen twisted
sleeve 24 rides on the uppern~st surface of rib 17, catch
36 is fully detached from latch--receiving surfaces 29
allowing connector head 11 to be separated from connector
body 12 by pulling them apart. Alternatively, as described
below, a reed lip 31 may be provided upon which the
cantilevered sleeve 24 slide to detach the catch 36 and
latch receiving surfaces 29_
CA 02182266 2005-03-11
This action of the sleeve 24 ramping upvthe:~surface of
the rib 17 is illustrated in Figure 4. Figure 4
characterizes the relationship of breathing apparatus
connector 13 to connector head ll and connector body 12.
5 As can be seen in Figure 4, when supporting breathing
apparatus connector 13 is slid over mated connector head 11
and connector body 12, connector head 11 is prevented from
being twisted in any direction by ribs 17. In this
position, receiving surface 29 is locked with catch 36
10 thereby preventing connector body 12 from being extracted
from its position within connector head 11.
Rib 17 possesses a sloping surface which has a minim~n
height at one edges) and a maximum height at about the
opposite edge(s). This slope creates a ramping surface
which connector head 11 can expand on. This is shown in
Figure 4C. As connector head 11 is twisted to the left,
from its position set forth in Figure 4B, the leading edge
of latch receiving surface 29 is allowed to ride up on the
minimum height section of the sloping surface of rib 17.
Of course, this movement can be done only when breathing
apparatus~connector 13 has been removed from its position
shown in Figure 4 about the connector head 11 and
connector body 12. As illustrated in Figure 4C, as
connector head 11 rides onto the sloping surface of cap 32
and stem 41, cantilevered sleeve 24 expands so that
connector head 11 and connector body 12 can be pulled
apart.
With respect to Figures 5, 5B and 5C, the locking
device 10 has a rib 17 and sloping lip 31 around the
circumference of mating surface 14. Slope may be gentle or
steep. This slope creates a ramping surface which sleeve
24 can expand on as connector body 12 is pulled in a
vertical direction away from the connector head 11. When
CA 02182266 2005-03-11
11
the connector body 12 is pulled away from the connector
head 11, catch 36 disengages from latch receiving surface
29 as sleeve 24 expands over lip 31. In this embodiment,
rib 17 does not have a raring surface and functions to
communicate with cut out portions 39 of sleeve 24.
As depicted in Figure 6, cantilevered sleeve 24 may
be incorporated into a rigid connector body 12. Catches 36
lock to latch receiving surfaces 29 of connector head 11 to
fozm latch 30 as depicted in Figures 6 and 6B. When
breathing apparatus connector 13 is provided over connector
body 12, sleeve 24 may not expand.
To facilitate securing of catch 36 to latch receiving
edges 29, li.p 31 may be provided with ascending 67 and
descending 68 romping surfaces upon which are located latch
receiving surfaces 29. Catch locking surface 73 is shaped
to articulate with ascending 67 and descending 68 romping
surfaces. In locked position, catch locking surface 73
articulates with ascending 67 and descending 68 romping
surfaces. If pressure is exerted such that connector body
12 and connector head 11 are pulled from each other along
a vertical axis, catch locking surface 73 rides up
ascending surface 67 and down descending surface 68,
thereby expanding sleeve 24 and disconnecting catch 36 from
latch receiving surfaces 29. However, if breathing
apparatus connector 13 is affixed over connector body 12
and connector head 11 when latch 30 is in place, a positive
pressure is fornied on the sleeve 24, preventing its
expansion and ensuring a secure connection.
This device l0 may be constructed from a variety of
materials. However, it is preferred that the connector
head 11 constructed of polyester, polycarbonate or
polysulfone to provide pliability and connector body 12 be
WO 95120419 2 3 8 2 2 6 b PCTIUS95101221
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constructed of a rigid material such as polypropylene.
Other materials, such as ABS° and DELRIN~ may be employed.
Although the description of the preferred embodiment
has been quite specific, it is contemplated that various
modifications may be made without deviating from the spirit
of the present invention. Accordingly, it is intended that
the scope of the present invention be dictated by the
appended claims rather than by the description of the
preferred embodiment.
