U.S. patent application number 15/825728 was filed with the patent office on 2018-06-21 for endotracheal tube having outer and inner cannulae.
The applicant listed for this patent is Eric D. BLOM, Brad H. QUINN. Invention is credited to Eric D. BLOM, Brad H. QUINN.
Application Number | 20180169363 15/825728 |
Document ID | / |
Family ID | 54067822 |
Filed Date | 2018-06-21 |
United States Patent
Application |
20180169363 |
Kind Code |
A1 |
BLOM; Eric D. ; et
al. |
June 21, 2018 |
ENDOTRACHEAL TUBE HAVING OUTER AND INNER CANNULAE
Abstract
A tracheal tube apparatus includes a cannula having first and
second ends. An inflatable cuff is formed on the cannula between
the first and second ends. A conduit extends from the cuff for
introducing an inflating fluid into the cuff when it is desired to
inflate the cuff and removing inflating fluid from the cuff when it
is desired to deflate the cuff. A gauge for indicating the
inflation pressure of the cuff is coupled in the conduit.
Inventors: |
BLOM; Eric D.; (Carmel,
IN) ; QUINN; Brad H.; (Indianapolis, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BLOM; Eric D.
QUINN; Brad H. |
Carmel
Indianapolis |
IN
IN |
US
US |
|
|
Family ID: |
54067822 |
Appl. No.: |
15/825728 |
Filed: |
November 29, 2017 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15443072 |
Feb 27, 2017 |
|
|
|
15825728 |
|
|
|
|
14728540 |
Jun 2, 2015 |
9579477 |
|
|
15443072 |
|
|
|
|
PCT/US2013/072237 |
Nov 27, 2013 |
|
|
|
14728540 |
|
|
|
|
13691924 |
Dec 3, 2012 |
8707956 |
|
|
PCT/US2013/072237 |
|
|
|
|
12885644 |
Sep 20, 2010 |
|
|
|
13691924 |
|
|
|
|
11318649 |
Dec 27, 2005 |
7987851 |
|
|
12885644 |
|
|
|
|
62135231 |
Mar 19, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 16/0434 20130101;
A61M 2205/6045 20130101; A61M 16/0816 20130101; A61M 2205/8206
20130101; A61M 2205/3331 20130101; A61M 2205/502 20130101; A61M
16/0479 20140204; A61M 16/0488 20130101; A61M 16/0461 20130101;
A61M 16/0427 20140204; A61M 16/0463 20130101; A61M 16/0497
20130101; A61M 16/0486 20140204; A61M 16/044 20130101 |
International
Class: |
A61M 16/04 20060101
A61M016/04; A61M 16/08 20060101 A61M016/08 |
Claims
1. (canceled)
2. An endotracheal tube apparatus comprising: an outer cannula
configured for insertion through a mouth of a wearer, down a
pharynx of the wearer, through a glottis of the wearer, and into a
trachea of the wearer, the outer cannula including a fenestration
along a length of the outer cannula, an inflatable cuff formed on
the outer cannula adjacent to the fenestration and the second end,
a first conduit extending from the cuff for introducing an
inflating fluid into the cuff when it is desired to inflate the
cuff and removing inflating fluid from the cuff when it is desired
to deflate the cuff, and a plurality of inner cannulas sized to be
selectively and separately inserted into, and removed from, the
outer cannula, wherein the plurality of inner cannulas include a
first inner cannula including a first and second lumen, the second
lumen configured to evacuate a region of the trachea of the wearer
adjacent the cuff, the second lumen including an opening which lies
adjacent the closest point in the fenestration to the cuff when the
first inner cannula is selectively inserted into a use orientation
in the outer cannula.
3. The apparatus of claim 2, further comprising a gauge for
indicating an inflation pressure of the cuff, the gauge coupled in
the first conduit.
4. The apparatus of claim 3, further comprising a one-way valve at
an end of the first conduit remote from the cuff, the one-way valve
preventing escape of inflating fluid from the cuff.
5. The apparatus of claim 2, further comprising a one-way valve at
an end of the first conduit remote from the cuff, the one-way valve
preventing escape of inflating fluid from the cuff.
6. The apparatus of claim 2, further comprising: a first coupler
provided on an outer end of the outer cannula, a second coupler
provided on an outer end of each inner cannula of the plurality of
inner cannulas, wherein one of the first and second couplers
including at least one surface for guiding the respective inner
cannula into a use orientation with respect to the outer cannula
when the inner cannula is inserted into the outer cannula, and the
other of the first and second couplers including a cooperating
surface for cooperating with the at least one surface for guiding
the inner cannula into the use orientation with respect to the
outer cannula.
7. The apparatus of claim 2, wherein the plurality of inner
cannulas include a second inner cannula including a lumen extending
therethrough, the second inner cannula being size to be inserted
into the outer cannula in place of the first inner cannula.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Ser. No.
15/443,072, which was filed on Feb. 27, 2017, which claimed
priority to U.S. Ser. No. 14/728,540, now U.S. Pat. No. 9,579,477,
which was filed on Jun. 2, 2015 and claimed priority to U.S. Ser.
No. 62/135,231 filed Mar. 19, 2015, and International Application
No. PCT/US2013/072237 filed Nov. 27, 2013, which claimed priority
to U.S. Ser. No. 13/691,924 filed Dec. 3, 2012, now U.S. Pat. No.
8,707,956, which is a continuation-in-part of U.S. Ser. No.
12/885,644 filed Sep. 20, 2010. U.S. Ser. No. 12/885,644 is itself
a divisional of U.S. Ser. No. 11/318,649 filed Dec. 27, 2005, now
U.S. Pat. No. 7,987,851. The disclosures of U.S. Ser. No.
15/443,072; U.S. Pat. No. 9,579,47, U.S. Ser. No. 62/135,231,
International Application No. PCT/US2013/072237, U.S. Pat. No.
8,707,956, U.S. Pat. No. 7,987,851, and U.S. Ser. No. 12/885,644,
are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to endotracheal tubes such
as, for example, orotracheal tubes and nasotracheal tubes.
BACKGROUND
[0003] A tracheal tube is typically a catheter that is inserted
into the trachea for the purpose of providing an airway for a
patient. An endotracheal tube is a specific type of tracheal tube
that is inserted through the mouth (orotracheal) or nose
(nasotracheal). Such endotracheal tubes are in contrast to a
tracheostomy tube, which is inserted into a tracheostoma following
a tracheostomy procedure, and a tracheal button, which may also be
inserted into a puncture through the paratracheal skin into the
trachea.
[0004] An endotracheal tube may be cuffed or uncuffed. Cuffed
endotracheal tubes include a cuff that can be inflated to minimize
the passage of secretions from the upper respiratory tract downward
into the lungs of a patient. One problem with cuffed endotracheal
tubes is the pooling of saliva and other secretions around the
inflated cuff and the potential for such secretions to leak past
the cuff and into the lungs.
[0005] The following are of interest: U.S. Pat. Nos.: 1,598,283;
2,892,458; 3,688,774; 3,996,939; 4,211,234; 4,223,411; 4,280,492;
4,304,228; 4,305,392; 4,315,505; 4,327,721; 4,449,523; 4,459,984;
4,469,100; 4,573,460; 4,584,998; 4,589,410; 4,596,248; 4,607,635;
4,627,433; 4,632,108; 4,637,389; 4,762,125; 4,834,087; 4,840,173;
4,852,565; 5,056,515; 5,067,497; 5,107,828; 5,123,922; 5,201,310;
5,217,008; 5,218,970; 5,255,676; 5,297,546; 5,329,921; 5,339,808;
5,343,857; 5,349,950; 5,391,205; 5,392,775; 5,458,139; 5,497,768;
5,507,279; 5,515,844; 5,584,288; 5,599,333; RE35,595; 5,687,767;
5,688,256; 5,746,199; 5,771,888; 5,957,978; 6,053,167; 6,089,225;
6,102,038; 6,105,577; 6,135,110; 6,135,111; 6,463,927; 6,722,367;
6,814,007; 7,404,329; U.S. patent publications: 2003/0084905;
2004/0123868; foreign/international patent publications: DE 25 05
123; DE 34 06 294; DE 37 20 482; DE 38 13 705; DE 195 13 831; DE
101 09 935; WO 99/07428; WO 99/12599; WO 00/32262; other
publications: Quick Reference Guide to Shiley's "Quality-Of Life"
Line of Tracheostomy Products, 1991; Granuloma Associated with
Fenestrated Tracheostomy Tubes, Padmanabhan Siddharth, MD, PhD,
FACS and Lawrence Mazzarella, MD, FACS, Case Reports, vol. 150,
Aug. 1985, pp. 279-280; Technical Support Information Connections
with the Passy-Muir Tracheostomy and Ventilator Speaking Valves,
one sheet; Tracheostomy and Laryngectomy Tubes, pp. 568 and 572;
Tracheostomy Tube Adult Home Care Guide, Shiley Tracheostomy
Products, Mallinckrodt Medical pp. 1-40; D. Hessler, MD, K. Rehder,
MD and S. W. Karveth, MD, "Tracheostomy Cannula for Speaking During
Artificial Respiration", Anesthesiology, vol. 25, No. 5, pp.
719-721 (1964). No representation is intended by this listing that
a thorough search of all material prior art has been conducted, or
that no better art than that listed is available. Nor should any
such representation be inferred. The disclosures of all of the
above are hereby incorporated herein by reference.
SUMMARY
[0006] According to an aspect, an endotracheal tube apparatus
includes an outer cannula having first and second ends. A
fenestration is provided along the length of the outer cannula
between the first and second ends. An inflatable cuff is formed on
the outer cannula between the fenestration and the second end. A
first conduit extends from the cuff for introducing an inflating
fluid into the cuff when it is desired to inflate the cuff and
removing inflating fluid from the cuff when it is desired to
deflate the cuff. An inner cannula is sized selectively to be
inserted into, and removed from, the outer cannula. The inner
cannula includes a second conduit to evacuate a region of a trachea
of a wearer adjacent the cuff. The second conduit includes an
opening which lies adjacent the closest point in the fenestration
to the cuff when the inner cannula is selectively inserted into a
use orientation in the outer cannula.
[0007] Illustratively, the apparatus further includes a gauge
coupled in the first conduit for indicating the inflation pressure
of the cuff.
[0008] Illustratively, the apparatus further includes a one-way
valve at an end of the first conduit remote from the cuff for
preventing escape of inflating fluid from the cuff.
[0009] Illustratively, the cuff comprises a sleeve including a
first end, a second end, and a third region between the first and
second ends. The sleeve is located around the outer cannula with at
least the first end of the sleeve between the outer cannula and the
third region of the sleeve.
[0010] Illustratively, the first and second ends of the sleeve are
both between the outer cannula and the third region of the
sleeve.
[0011] Illustratively, the apparatus further comprises a first
coupler provided on an outer end of the outer cannula and a second
coupler provided on an outer end of the inner cannula. Each of the
first and second couplers is provided with at least one cooperating
surface for guiding the inner cannula into a predetermined
orientation with respect to the outer cannula when the inner
cannula is inserted into the outer cannula.
[0012] Illustratively, the apparatus further comprises at least one
tab provided on an outer end of one of the outer cannula and the
inner cannula. The at least one tab includes an engaging surface.
At least one coupler is provided on an outer end of the other one
of the outer cannula and the inner cannula for engagement by the at
least one tab. The at least one coupler includes a portion for
cooperating with the engaging surface for orienting the inner
cannula in a predetermined orientation with respect to the outer
cannula.
[0013] Illustratively, the at least one tab is flexibly formed or
mounted to said one of the outer cannula and the inner cannula.
[0014] According to another aspect, a tracheal tube apparatus
includes a cannula having first and second ends. An inflatable cuff
is formed on the cannula between the first and second ends. A
conduit extends from the cuff for introducing an inflating fluid
into the cuff when it is desired to inflate the cuff and removing
inflating fluid from the cuff when it is desired to deflate the
cuff. A gauge is coupled to the conduit for indicating the
inflation pressure of the cuff.
[0015] Illustratively, the apparatus further includes a one-way
valve at an end of the conduit remote from the cuff. The one-way
valve prevents escape of inflating fluid from the cuff.
[0016] Illustratively, the cuff comprises a sleeve including a
first end, a second end, and a third region between the first and
second ends. The sleeve is located around the cannula with at least
the first end of the sleeve between the cannula and the third
region of the sleeve.
[0017] Illustratively, the first end of the sleeve and the second
end of the sleeve are both between the cannula and the third region
of the sleeve.
[0018] According to another aspect, an endotracheal tube apparatus
is disclosed. The endotracheal tube comprises an outer cannula
having a first longitudinal end and a second longitudinal end. The
outer cannula has an outer surface that is devoid of openings
between the first longitudinal end and the second longitudinal end.
The endotracheal tube also comprises an inner cannula sized to be
selectively inserted into, and removed from, the outer cannula. The
inner cannula has a first longitudinal end, a second longitudinal
end, and an outer surface that is devoid of openings between the
first longitudinal end and the second longitudinal end.
[0019] In some embodiments, the endotracheal tube apparatus may
further comprise an inflatable cuff formed on the outer cannula
between its first and second longitudinal ends.
[0020] In some embodiments, the endotracheal tube apparatus may
further comprise a conduit extending from the cuff for introducing
fluid into the cuff when it is desired to inflate the cuff and
removing fluid from the cuff when it is desired to deflate the
cuff.
[0021] Additionally, in some embodiments, the endotracheal tube
apparatus may further comprise a first coupler provided on the
second longitudinal end of the outer cannula and a second coupler
provided on the second longitudinal end of the inner cannula. One
of the first and second couplers may be provided with at least one
surface for guiding the inner cannula into the use orientation with
respect to the outer cannula when the inner cannula is inserted
into the outer cannula, and the other of the first and second
couplers may be provided with a cooperating surface for cooperating
with the at least one surface for guiding the inner cannula into
the use orientation with respect to the outer cannula.
[0022] According to another aspect, a method of using an
endotracheal tube apparatus is disclosed. The method comprises
inserting an endotracheal tube orally or nasally into a trachea of
a patient. The endotracheal tube comprises an outer cannula having
a first longitudinal end, a second longitudinal end, and an outer
surface that is devoid of openings between the first longitudinal
end and the second longitudinal end. The method also comprises
removing an inner cannula from the outer cannula. The inner cannula
has a first longitudinal end, a second longitudinal end, and an
outer surface that is devoid of openings between the first
longitudinal end and the second longitudinal end. The method
further comprises maintaining the outer cannula in the trachea of
the patient and inserting the inner cannula into the outer cannula
with the outer cannula in the trachea of the patient.
[0023] In some embodiments, the method may further comprise
inflating a cuff formed on the outer cannula.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention may best be understood by referring to the
following detailed description and accompanying drawings which
illustrate the invention. In the drawings:
[0025] FIG. 1 illustrates a fragmentary perspective view of a
system according to the invention in a disassembled
configuration;
[0026] FIG. 1a illustrates a longitudinal sectional side
elevational view of the anatomy of the upper airway of a wearer
with the apparatus illustrated in FIG. 1 in place;
[0027] FIG. 2 illustrates a perspective view of a portion of the
system illustrated in FIG. 1;
[0028] FIG. 3 illustrates a perspective view of a portion of the
system illustrated in FIG. 1;
[0029] FIG. 4 illustrates an enlarged longitudinal sectional side
elevational view of a detail of FIGS. 1 and 3, taken generally
along section lines 4-4 of FIG. 3;
[0030] FIG. 5 illustrates an enlarged longitudinal sectional side
elevational view of a detail of FIGS. 1 and 2, taken generally
along section lines 5-5 of FIG. 2;
[0031] FIG. 5a illustrates an enlarged longitudinal sectional side
elevational view of an alternative detail to the detail illustrated
in FIG. 5;
[0032] FIGS. 6a-c illustrate enlarged front elevational, side
elevational and rear elevational views, respectively, of a detail
of FIGS. 1 and 2;
[0033] FIGS. 7a-e illustrate schematic circuit diagrams of the
detail illustrated in FIGS. 6a-c;
[0034] FIG. 8 illustrates a perspective view of another
endotracheal tube including inner and outer cannulae; and
[0035] FIG. 9 is a longitudinal sectional side elevation view
illustrating the endotracheal tube of FIG. 8 inserted into an upper
airway of a patient.
DETAILED DESCRIPTIONS OF ILLUSTRATIVE EMBODIMENTS
[0036] While the concepts of the present disclosure are susceptible
to various modifications and alternative forms, specific exemplary
embodiments thereof have been illustrated by way of example in the
drawings and will herein be described in detail. It should be
understood, however, that there is no intent to limit the concepts
of the present disclosure to the particular forms disclosed, but on
the contrary, the intention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the invention as defined by the appended claims.
[0037] Referring now particularly to FIGS. 1 and 1a, an
endotracheal tube system 10, here an orotracheal tube system,
includes an outer cannula 12 for insertion through the mouth of a
wearer 20, down the wearer 20's pharynx 24, through the wearer 20's
glottis 22 and into the wearer 20's trachea 18. Outer cannula 12
includes an inflatable cuff 16. Cuff 16 lies in the trachea 18 of
the wearer 20 below the wearer 20's glottis 22. Outer cannula 12
also includes a first port 26 which resides outside the mouth of
the wearer 20 during use and a second port 28 which resides inside
the trachea 18 of the wearer 20 below cuff 16 during use. The cuff
16 is inflatable through a conduit 30 once the outer cannula 12 is
in place in the trachea 18 to minimize the passage of secretions 32
from the upper respiratory tract downward into the lungs of the
wearer 20. Such secretions 32 pool above the cuff 16 (that is, on
the side of the cuff 16 opposite the lungs) when the cuff 16 is
inflated in place. The construction of the cuff 16 as a sleeve 42,
FIG. 5, with its upper and lower ends 44, 46, respectively, tucked
under, rather than extending beyond the cuff 16 up and down the
outer sidewall of the outer cannula 12, is aided by the use of
thin-walled material for the cuff 16. In an alternative embodiment,
illustrated in FIG. 5a, only upper end 44' is tucked under, rather
than extending beyond the cuff 16 up the outer sidewall of the
outer cannula 12'. The constructions illustrated in FIGS. 5 and 5a
provide certain benefits which will be discussed subsequently.
[0038] The outer cannula 12 includes (a) fenestration(s) 56.
Although two such fenestrations 56 are illustrated, it should be
understood that any number of fenestrations 56 may be provided in
the outer cannula 12 for this purpose. The construction of cuff 16,
with its doubled-over upper and lower ends 44, 46, respectively,
(FIG. 5) or doubled-over upper end 44' (FIG. 5a), permits location
of the fenestration(s) 56 low (that is, more toward the lungs of
the wearer 20) on the outer cannula 12. The proximity of the cuff
16 to the fenestration(s) 56 also provides some additional
protection of the tissue of the trachea 18 against irritation and
damage occasioned by contact with the edges of the fenestration(s)
56 by virtue of the standoff provided by the inflated cuff 16.
[0039] Referring now particularly to FIGS. 1 and 3, an inner
cannula 60 is inserted into the lumen 62 of the outer cannula 12.
To evacuate pooling secretions 32, a conduit 70 extends down the
sidewall of inner cannula 60. Conduit 70 terminates at an open end
72 at the bottommost extent of fenestrations 56 to expose the
secretions 32 to suction at open end 72 of tube 70 provided by a
suction source 73 at the outer end of inner cannula 60. Owing to
the construction of cuff 16 with its doubled-under end 44, this
location generally coincides with the top of the cuff 16 at the
bottommost extent of fenestration 56. Owing to this construction,
extraction of secretions 32 is somewhat more predicable and
complete.
[0040] In addition, it is contemplated that replacement of the
inner cannula 60 may occur more frequently and with less difficulty
and without much of the trauma that might attend replacement of
outer cannula 12, which is typically placed in the trachea for a
longer term. Typically, both the outer 12 and inner cannulae 60 are
constructed from suitable filled and/or unfilled resin(s) and/or
polymer(s). Inner cannula 60 typically can be relatively
straightforwardly replaced by disconnecting it from the ventilator
74 (illustrated diagrammatically) to which the outer end 76 of
inner cannula 60 is attached in use and withdrawing inner cannula
60 from outer cannula 12. Because of the relative ease with which
inner cannula 60 can be removed, disposed of if appropriate, and
replaced with a fresh cannula 60 having a fresh tube 70, providing
tube 70 on inner cannula 60 rather than on outer cannula 12 affords
somewhat more reliable patency of tube 70 than if the tube 70 were
to be provided in outer cannula 12 which, as noted above, is
typically not so readily removed for cleaning or replacement.
[0041] Referring now to FIG. 1, the inner cannula 60 is releasably
fixed to an outer cannula 12 by one or more (two in the illustrated
embodiment) locking tabs 100 which may be formed with, and from the
same material as, the coupler 76 of cannula 60 by which cannula 60
is coupled to the ventilator 74. The tabs 100 are flexibly formed
or mounted to the coupler 76 of inner cannula 60. The tabs 100 are
provided with engaging surfaces 106. A coupler 108 is provided at
the proximal end 54 of outer cannula 12. The coupler 108 includes a
notch 114 for receiving the portion of each tab 100 which extends
beyond engaging surfaces 106 and portions 116 for capturing
engaging surfaces 106. This configuration also promotes correct
orientation of inner cannula 60 with the fenestration(s) (56 in
FIG. 1) of outer cannula 12 when inner cannula 60 is inserted into
outer cannula 12.
[0042] Referring to FIGS. 1 and 2, a digital pressure gauge 304 is
inserted into the conduit 30 between a fitting 302 and cuff 16 by a
fitting 306 provided on gauge 304. Fitting 302 is configured
complementarily to a fitting on a source 307 of compressed air,
such as a syringe. Such a fitting might be, for example, a Luer
lock fitting or other suitable fitting to couple the compressed air
source to fitting 302 for this purpose. Fitting 302 may also
include a one-way valve of a suitable type, such as, for example, a
ball valve, to prevent the escape of cuff 16-inflating air,
permitting the compressed air source 307 to be disconnected from
fitting 302 once cuff 16 is inflated to a suitable pressure.
[0043] The schematic and block circuit diagram descriptions that
follow identify specific integrated circuits and other components
and in many cases specific sources for these. Specific terminal and
pin names and numbers are generally given in connection with these
for the purposes of completeness. It is to be understood that these
terminal and pin identifiers are provided for these specifically
identified components. It is to be understood that this does not
constitute a representation, nor should any such representation be
inferred, that the specific components, component values or sources
are the only components available from the same or any other
sources capable of performing the necessary functions. It is
further to be understood that other suitable components available
from the same or different sources may not use the same
terminal/pin identifiers as those provided in this description.
[0044] The gauge 304 removed from its housing 305 is illustrated in
FIGS. 6a-c. An electrical schematic of gauge 304 is illustrated in
FIGS. 7a-e. As illustrated in FIGS. 1, 2, 6a, 6b and 7a, gauge 304
includes a two digit (seven segments each) liquid crystal display
(LCD) 310 which illustratively is a Glory Sound (Asia) Ltd., AE359
type DS-M2684-F display. Referring to FIGS. 6b and 7b, the driver
312 for display 310 illustratively is a Freescale Semiconductor
MC9S08QB4QFN microcontroller (.mu.C). Pins 1-4, the Vdd, Vrefh,
Vrefl and Vss terminals, respectively, of driver 312 are coupled to
the gauge 304's+Vbat, +Vbat, common and common terminals,
respectively. Vrefh is coupled to+Vbat through a 1.8 .mu.H
inductor. +Vbat and common are the+and-terminals, respectively, of,
for example, a 3V lithium PC 2 pin mount, 170 mAh coin cell 313
such as, for example, a Renata SA type 614-CR2025FH-MFR-LF coin
cell. See FIGS. 6a-c.
[0045] Referring again to FIG. 7b, the parallel combination of a
2.2 .mu.F capacitor and a 100 nF capacitor is coupled across pins 1
and 4 of .mu.C 312. The parallel combination of a 2.2 F capacitor
and a 100 nF capacitor is coupled across pins 2 and 3. Pins 5-24,
terminals PB7/EXTL, PB6/XTL, PBS, PB4, PC1, PC0, PB3/AD7, PB2/AD6,
PB1/TXD/ADS, PB0/RXD/AD4, PA7, PA6, PA3/AD3, PA2/AD2, PA1/ADL
PA0/AD0, PC7, PC6, PA5/*RST, and PA4/BKGD, respectively, of driver
312 are coupled to LCD COM, LCD segment 1G, LCD segment 1F, LCD
segment 1E, LCD segment 2B, LCD segment 2A, LCD segment 1D, LCD
segment 1C, LCD segment 1B, LCD segment 1A, LCD segment 2G, LCD
segment 2F, LCD segment 2E, not connected, the gauge 304's
TEMPerature terminal, the gauge 304's NET_PRESSure terminal, LCD
segment 2D, LCD segment 2C, through a 100 nF capacitor to gauge
304's common terminal, and through a 4.7 K.OMEGA. resistor to+Vbat.
Another 4.7 K.OMEGA. resistor is coupled between pin 23 of driver
312 and+Vbat.
[0046] Referring to FIGS. 6b, 6c and 7c, pressure at port 306,
which is the cuff 16 inflation pressure, is monitored by a pressure
sensor 320, illustratively a Freescale Semiconductor type MPX10 or
MPX12 uncompensated silicon pressure sensor. Sensor 320 pins 1-4
are coupled respectively to the gauge 304 common, through a 10
K.OMEGA. resistor to the non-inverting (+) input terminal, pin 3,
of a differential amplifier 322, to gauge 304's+Vbat terminal, and
through a 10 K.OMEGA. resistor to amplifier 322's inverting (-)
input terminal, pin 2 Amplifier 322 illustratively is one-fourth of
a National Semiconductor type LMC6464AIM quad differential
amplifier. Feedback is provided from the output terminal, pin 1, of
amplifier 322 to the-input terminal of amplifier 322 through a 100
K.OMEGA. resistor. Pin 4 of amplifier 322 is coupled to+Vbat. Pin
11 of amplifier 322 is coupled to common. The parallel combination
of a 2.2 .mu.F capacitor and a 100 nF capacitor is coupled
across+Vbat and common. Pin 1 of amplifier 322 is coupled to
a+terminal, pin 5 of a differential amplifier 324. An output
terminal, pin 7, of amplifier 324 is coupled to amplifier
324's-input terminal, pin 6, configuring amplifier 324 as a unity
gain buffer. Pin 7 of amplifier 324 forms the gauge 304's
NET_PRESSure terminal Amplifier 324 illustratively is one-fourth of
a National Semiconductor type LMC6464AIM quad differential
amplifier.
[0047] Referring to FIG. 7d, a 10 K.OMEGA., 1% thermistor 330, such
as a Vishay type 71-TFPT1206L1002FV thermistor, and a 10 K.OMEGA.,
1% resistor are coupled in series between+Vbat and common. The
common terminal of thermistor 330 and the 10 K.OMEGA. resistor is
coupled to the+input terminal, pin 12, of a differential amplifier
332. An output terminal, pin 14, of amplifier 332 is coupled to
amplifier 332's-input terminal, pin 13, configuring amplifier 332
as a unity gain buffer. Pin 14 of amplifier 332 forms the gauge
304's TEMPerature terminal Amplifier 332 illustratively is
one-fourth of a National Semiconductor type LMC6464AIM quad
differential amplifier. Referring to FIGS. 6a, 6b and 7e, +Vbat is
supplied to the illustrated circuitry through a suitable switch
334, such as a Snaptron dome switch.
[0048] The topography of gauge 304 can best be understood by
referring to FIGS. 6a-c, where the relative locations of fitting
306, LCD 310, driver 312, battery 313, pressure sensor 320 and
switch 334 can be readily ascertained. Gauge 304 is configured to
be reliable yet inexpensive in keeping with the philosophy that
inner cannula 60 be rendered disposable. However, gauge 304 can be
provided with a T-junction and conduit 30 and fitting 302 with
appropriate complementary fittings, so that the T-junction can
readily be disconnected from and reconnected into the conduit 30
between cuff 16 and fitting 302, should it be appropriate to retain
the gauge 304 and dispose of the inner cannula 60. In such
embodiments, gauge 304 could be reused as long as it remained
operable.
[0049] Referring now to FIG. 8, an endotracheal tube apparatus 410
is shown. In the illustrative embodiment, the endotracheal tube
apparatus is an orotracheal apparatus configured for insertion
through a patient's mouth and into his or her trachea. In other
embodiments, the endotracheal tube apparatus may be a nasotracheal
apparatus configured for insertion through a patient's nose. The
apparatus 410 includes an outer cannula 412 and an inner cannula
414 sized to be selectively inserted into, and removed from, the
outer cannula 412. The cannulae 412, 414 are formed as components
from polyvinyl chloride but may also be formed from silicone or
other suitable biocompatible material(s).
[0050] The outer cannula 412 has a distal longitudinal end 416 and
a proximal longitudinal end 418. A passageway or lumen 420 extends
through ports 422, 424 defined in the ends 416, 418, respectively.
The cannula 412 also has an outer surface 426 that extends between
the ends 416, 418. As shown in FIG. 8, the outer surface 426 is
devoid of any fenestrations or other openings. In the illustrative
embodiment, an inflatable cuff 428 is provided on the outer surface
426 between the ends 416, 18. The cuff 428 is inflatable through a
conduit 430 once the outer cannula 412 is in place in the trachea,
as described in greater detail below.
[0051] The inner cannula 414 is sized to be inserted into the lumen
420 of the outer cannula 412. The inner cannula 414 has a distal
longitudinal end 436 and a proximal longitudinal end 438. A
passageway or lumen 440 extends through ports 442, 444 defined in
the ends 436, 438, respectively. The cannula 414 also has an outer
surface 46 that extends between the ends 436, 438. As shown in FIG.
8, the outer surface 446 is devoid of any openings. In the
illustrative embodiment, the inner cannula 414 may be coupled to a
ventilator (not shown).
[0052] The inner cannula 414 is releasably fixed to an outer
cannula 412 via an attachment mechanism 448. In the illustrative
embodiment, the attachment mechanism 448 includes one or more (two
in the illustrated embodiment) couplers or locking tabs 450 that
are flexibly formed or mounted to the proximal longitudinal end 438
of the inner cannula 414. The tabs 450 are provided with engaging
surfaces 452. The attachment mechanism 448 also includes a coupler
454 at the proximal longitudinal end 418 of the outer cannula 412.
The coupler 454 includes a notch 456 for receiving the portion of
each tab 450 which extends beyond engaging surfaces 452 and
portions 458 for capturing engaging surfaces 452. This
configuration also promotes correct orientation of inner cannula
414 within outer cannula 412.
[0053] In use, the endotracheal tube apparatus 410 is inserted
through a patient's mouth 470, down the patient's pharynx 472,
through the patient's glottis 474, and into the patient's trachea
476, as shown in FIG. 9. The port 424 at the proximal longitudinal
end 418 of the outer cannula 412 is positioned outside the
patient's mouth 470 during use and the port 422 at the distal
longitudinal end 16 of the outer cannula 412 is positioned inside
the trachea 476 below cuff 428 during use. As described above, the
cuff 428 is inflatable through a conduit 30 once the outer cannula
412 is in place in the trachea 476 to minimize the passage of
secretions 480 from the upper respiratory tract downward into the
patient's lungs. Such secretions 480 pool above the cuff 428 (that
is, on the side of the cuff 428 opposite the lungs) when the cuff
428 is inflated in place.
[0054] As described above, the inner cannula 414 may be removed
from the outer cannula 412. It is contemplated that replacement of
the inner cannula 414 may occur more frequently and with less
difficulty and without much of the trauma that might attend
replacement of the outer cannula 412, which is typically placed in
the trachea for a longer term. The inner cannula 414 typically can
be relatively straightforwardly replaced by disconnecting it from
the ventilator (if any), releasing the coupler(s) 450 and
withdrawing the inner cannula 414 from the outer cannula 412. The
inner cannula 414 thus can be removed, disposed of if appropriate,
and replaced with a fresh cannula 414 with relative ease.
[0055] While the disclosure has been illustrated and described in
detail in the drawings and foregoing description, such illustration
and description is to be considered as exemplary and not
restrictive in character, it being understood that only
illustrative embodiments have been illustrated and described and
that all changes and modifications that come within the spirit of
the disclosure are desired to be protected.
[0056] There are a plurality of advantages of the present
disclosure arising from the various features of the method,
apparatus, and system described herein. It will be noted that
alternative embodiments of the method, apparatus, and system of the
present disclosure may not include all of the features described
yet still benefit from at least some of the advantages of such
features. Those of ordinary skill in the art may readily devise
their own implementations of the method, apparatus, and system that
incorporate one or more of the features of the present invention
and fall within the spirit and scope of the present disclosure as
defined by the appended claims.
* * * * *