U.S. patent application number 14/877769 was filed with the patent office on 2016-01-28 for cuff pressure measurement device for a tracheal tube.
The applicant listed for this patent is COVIDIEN LP. Invention is credited to John Burns, Sarah Hayman, Lockett Wood.
Application Number | 20160022939 14/877769 |
Document ID | / |
Family ID | 49511593 |
Filed Date | 2016-01-28 |
United States Patent
Application |
20160022939 |
Kind Code |
A1 |
Wood; Lockett ; et
al. |
January 28, 2016 |
CUFF PRESSURE MEASUREMENT DEVICE FOR A TRACHEAL TUBE
Abstract
According to various embodiments, methods and systems for
determining pressure in an inflatable cuff of a tracheal tube may
employ pressure transducers associated with a cuff inflation line
or a pilot balloon assembly. The pressure transducers may be
implemented to provide continuous or intermittent cuff pressure.
Also provided are tracheal tubes with adapters or other devices
that incorporate pressure transducers. The tracheal tubes may
facilitate wireless cuff pressure monitoring.
Inventors: |
Wood; Lockett; (Lyons,
CO) ; Burns; John; (Longmont, CO) ; Hayman;
Sarah; (Boulder, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
COVIDIEN LP |
MANSFIELD |
MA |
US |
|
|
Family ID: |
49511593 |
Appl. No.: |
14/877769 |
Filed: |
October 7, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13461292 |
May 1, 2012 |
9180268 |
|
|
14877769 |
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Current U.S.
Class: |
128/207.15 |
Current CPC
Class: |
A61M 2205/3569 20130101;
A61M 16/044 20130101; A61M 2205/3592 20130101; A61M 16/0486
20140204; A61M 16/20 20130101; A61M 16/0445 20140204 |
International
Class: |
A61M 16/04 20060101
A61M016/04; A61M 16/20 20060101 A61M016/20 |
Claims
1. A tracheal tube comprising: a conduit configured to be inserted
into a trachea of a subject; an inflatable cuff disposed on the
conduit and configured to contact the trachea of the subject; an
inflation line in fluid communication with the inflatable cuff; a
pilot balloon associated with a proximal end of the inflation line;
and a pressure transducer associated with the pilot balloon and
comprising an interior surface exposed to an interior space of the
pilot balloon and an exterior surface exposed to ambient air.
2. The tracheal tube of claim 1, comprising an antenna coupled to
the pressure transducer and disposed about a wall of the pilot
balloon.
3. The tracheal tube of claim 1, wherein the pressure transducer is
coupled to a wall of the pilot balloon.
4. The tracheal tube of claim 1, wherein the pressure transducer is
disposed on a rigid substrate and wherein a wall of the pilot
balloon is adhered to a surface of the rigid substrate.
5. The tracheal tube of claim 4, wherein the pressure transducer
comprises a membrane.
6. A tracheal tube comprising: a conduit configured to be inserted
into a trachea of a subject; an inflatable cuff disposed on the
conduit and configured to contact the trachea of the subject; an
inflation line in fluid communication with the inflatable cuff; a
pilot balloon associated with a proximal end of the inflation line;
and an adapter coupled to the pilot balloon and comprising an
interior surface in fluid communication with an interior space of
the pilot balloon; a pressure transducer associated with the
adapter and comprising an interior surface in fluid communication
with the interior space of the pilot balloon and an exterior
surface exposed to ambient air; and a valve coupled to the adapter
and configured to allow fluid to flow through the adapter and into
the inflation line via the pilot balloon when open and to prevent
fluid from entering the inflation line when closed.
7. The tracheal tube of claim 6, comprising antennas disposed on
diametrically opposed surface of the adapter.
8. The tracheal tube of claim 7, wherein the antennas form a spiral
or curved shape about the pressure transducer.
9. The tracheal tube of claim 6, wherein the exterior surface of
the pressure transducer forms a part of a transducer side of the
adapter.
10. The tracheal tube of claim 9, comprising at least one antenna
disposed on the transducer side of the adapter.
11. The tracheal tube of claim 6, wherein the adapter is coupled to
the pilot balloon at a distal end of the adapter and wherein the
valve is oriented at a proximal end of the adapter.
12. The tracheal tube of claim 6, wherein the adapter comprises a
barbed end configured to coupled the adapter to the pilot
balloon.
13. The tracheal tube of claim 6, wherein the pressure transducer
comprises a flexible membrane comprising an electrode surface.
14. The tracheal tube of claim 6, wherein the adapter is
removable.
15. The tracheal tube of claim 6, wherein the adapter comprises a
spherical or elliptical shape.
17. A tracheal tube comprising, a conduit configured to be inserted
into a trachea of a subject; an inflatable cuff disposed on the
conduit and configured to contact the trachea of the subject; an
inflation line in fluid communication with the inflatable cuff; a
pilot balloon associated with a proximal end of the inflation line;
and a pressure transducer associated with the pilot balloon and
disposed on a surface of a substrate coupled to the pilot
balloon.
18. The tracheal tube of claim 17, wherein the pilot balloon is
coupled to an exterior surface of the substrate.
19. The tracheal tube of claim 17, wherein the pilot balloon is
coupled to an interior surface of the substrate.
20. The tracheal tube of claim 17, comprising antennas disposed on
an exterior surface of the substrate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 13/461,292 filed May 1, 2012, the contents of which are hereby
incorporated by reference in their entirety.
BACKGROUND
[0002] The present disclosure relates generally to medical devices
and, more particularly, to airway devices, such as tracheal
tubes.
[0003] This section is intended to introduce the reader to aspects
of the art that may be related to various aspects of the present
disclosure, which are described and/or claimed below. This
discussion is believed to be helpful in providing the reader with
background information to facilitate a better understanding of the
various aspects of the present disclosure. Accordingly, it should
be understood that these statements are to be read in this light,
and not as admissions of prior art.
[0004] In the course of treating a patient, a tube or other medical
device may be used to control the flow of air, food, fluids, or
other substances into the patient. For example, tracheal tubes may
be used to control the flow of air or other gases through a
patient's trachea and into the lungs, for example during patient
ventilation. Such tracheal tubes may include endotracheal (ET)
tubes, tracheotomy tubes, or transtracheal tubes. In many
instances, it is desirable to provide a seal between the outside of
the tube or device and the interior of the passage in which the
tube or device is inserted. In this way, substances can only flow
through the passage via the tube or other medical device, allowing
a medical practitioner to maintain control over the type and amount
of substances flowing into and out of the patient.
[0005] To seal these types of tracheal tubes, an inflatable cuff
may be associated with the tubes. When inflated, the cuff generally
expands into the surrounding trachea (or, in the case of laryngeal
masks, over the trachea) to seal the tracheal passage around the
tube to facilitate the controlled delivery of gases via a medical
device (e.g., through the tube). As many patients are intubated for
several days, healthcare workers may need to balance achieving a
high-quality tracheal seal with possible patient discomfort. For
example, if improperly overinflated, the pressure and/or frictional
force of certain types of inflated cuffs against the tracheal walls
may result in some tracheal tissue damage. While a cuff may be
inflated at lower pressure to avoid such damage, this may lower the
quality of the cuff's seal against the trachea. Low cuff inflation
pressures may also be associated with allowing folds to form in the
walls of the cuff that may serve as leak paths for air as well as
microbe-laden secretions.
[0006] Additionally, the quality of a cuff's seal against the
tracheal passageway may suffer over the duration of a patient's
intubation time. For example, a seal may be compromised when a
patient coughs, which may dislodge the cuff from a sealed position.
Further, when the tracheal tube is jostled during patient transport
or medical procedures, the force of the movement may shift the
position of the inflatable cuff within the trachea, allowing gaps
to form between the cuff and the tracheal walls. Accordingly, it
may be desirable to monitor the internal pressure in the cuff to
determine if the cuff is properly inflated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Advantages of the disclosure may become apparent upon
reading the following detailed description and upon reference to
the drawings in which:
[0008] FIG. 1 illustrates a system including a tracheal tube with a
pressure transducer for monitoring cuff pressure according to
embodiments of the present techniques;
[0009] FIG. 2 is a perspective view of an endotracheal tube that
may be used in conjunction with the system of FIG. 1;
[0010] FIG. 3 is a perspective view of an endotracheal tube with a
pilot balloon assembly including a pressure transducer that may be
used in conjunction with the system of FIG. 1;
[0011] FIG. 4 is a perspective view of a pilot balloon assembly
including a proximal adapter with a pressure transducer;
[0012] FIG. 5 is a perspective view of a pilot balloon assembly
including a pressure transducer incorporated into a balloon
wall;
[0013] FIG. 6 is a perspective view of a pilot balloon assembly
including a pressure transducer that forms a side of the pilot
balloon;
[0014] FIG. 7 is a side view of a pilot balloon assembly of FIG.
6;
[0015] FIG. 8 is a perspective view of an endotracheal tube with an
inflation line and an in-line adapter including pressure transducer
that may be used in conjunction with the system of FIG. 1; and
[0016] FIG. 9 is a side view of an example of an in-line adapter
including a pressure transducer.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0017] One or more specific embodiments of the present disclosure
will be described below. In an effort to provide a concise
description of these embodiments, not all features of an actual
implementation are described in the specification. It should be
appreciated that in the development of any such actual
implementation, as in any engineering or design project, numerous
implementation-specific decisions must be made to achieve the
developers' specific goals, such as compliance with system-related
and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that
such a development effort might be complex and time consuming, but
would nevertheless be a routine undertaking of design, fabrication,
and manufacture for those of ordinary skill having the benefit of
this disclosure.
[0018] A tracheal tube may be used to seal a patient's airway and
provide positive pressure to the lungs when properly inserted into
a patient's trachea. A high quality seal of a cuff against the
tracheal walls may assist in isolating the lower airway and
anchoring the tube in place. However, a conforming seal is often
difficult to obtain over long-term intubation. Physicians may
attempt to determine the quality of a cuff seal by monitoring
inflation pressure via devices such as manometers that are
temporarily attached to the exposed valve of the cuff inflation
line. However, these devices are generally used intermittently for
spot checks of cuff pressure and, therefore, add to the workflow of
clinicians. Further, the devices include connecting tubes to
transfer gas from the cuff inflation line to pressure sensors. When
the devices are disconnected, the air transferred to the devices is
lost to the system. Accordingly, each measurement results in an
overall decrease in cuff pressure, which may influence the
integrity of the cuff seal. Other techniques may involve a
qualitative assessment of the stiffness of a pilot balloon
associated with the exposed end of the cuff inflation line.
However, the pilot balloon stiffness does not provide a
quantitative measurement of cuff pressure.
[0019] Accordingly, the disclosed embodiments provide a more
accurate method and system for determining trachea pressure by
obtaining a measurement of pressure with pressure transducers
associated with the cuff inflation line or the pilot balloon
assembly. Such pressure transducers may include wireless sensors
that are capable of communicating with a patient monitor. In
particular embodiments, the pressure transducer may include
components that are exposed to the interior space of the inflation
line system (e.g., including the fluid enclosed by the cuff, the
inflation line, and any components in fluid communication the cuff
and the inflation line) and components that are exposed to ambient
air. In one embodiment, the pressure transducers may be associated
with an adapter that is used in conjunction with an inflation line
or pilot balloon assembly. For example, a pilot balloon assembly
may typically terminate at a proximal end in a valve that opens to
allow air to enter or leave the inflation line. As provided herein,
an adapter incorporating the valve may include a pressure
transducer that is in fluid communication with the pilot balloon
and the inflation line. Such an embodiment may provide
manufacturing advantages because the tracheal tube, inflation line,
and pilot balloon are unchanged. In another embodiment, the
pressure transducer may be embedded in or incorporated into a wall
of the pilot balloon itself. In yet additional embodiments, a
pressure transducer may be incorporated into the inflation line.
For example, an in-line adapter may bridge two sections of
inflation line and provide a pressure transducer surface that is in
fluid communication with the inflation line.
[0020] In certain embodiments, the disclosed tracheal tubes,
systems, and methods may be used in conjunction with any
appropriate medical device, including a tracheal tube, a feeding
tube, an endotracheal tube, a tracheotomy tube, a double-lumen
tracheal tube (e.g., an endobroncheal tube), a circuit, an airway
accessory, a connector, an adapter, a filter, a humidifier, a
nebulizer, nasal cannula, or a supraglottal mask/tube. The present
techniques may also be used to monitor any patient benefiting from
mechanical ventilation, e.g., positive pressure ventilation.
[0021] FIG. 1 shows an exemplary tracheal tube system 10 that has
been inserted into the trachea of a patient. The system 10 includes
a tracheal tube 12, shown here as an endotracheal tube, with an
inflatable balloon cuff 14 that may be inflated via inflation line
18 to form a seal against the tracheal walls. The tracheal tube 12
may also include a pressure transducer 20 that is in fluid
communication with the cuff 14. In certain embodiments, the
pressure transducer 20 may be coupled to a medical device, such as
a ventilator 22 or a monitor 30. The monitor 30 and/or the
ventilator 22 may be configured to monitor pressure in the cuff 14
and, in particular embodiments, the pressure in the tracheal space
24.
[0022] The system 10 may also include devices that facilitate
positive pressure ventilation of a patient, such as the ventilator
22, which may include any ventilator, such as those available from
Nellcor Puritan Bennett LLC. The system may also include a monitor
30 that may be configured to implement embodiments of the present
disclosure to determine pressures based upon the pressure in the
cuff 14 or another cuff. It should be understood that the monitor
30 may be a stand-alone device or may, in embodiments, be
integrated into a single device with, for example, the ventilator
22.
[0023] The monitor 30 may include processing circuitry, such as a
microprocessor 32 coupled to an internal bus 34 and a display 36.
In an embodiment, the monitor 30 may be configured to communicate
with the tube, for example via the pressure transducer 20 or an
associated antenna, to obtain signals from the pressure transducer
20. In certain embodiments, the communication may also provide
calibration information for the tube 12. The information may then
be stored in mass storage device 40, such as RAM, PROM, optical
storage devices, flash memory devices, hardware storage devices,
magnetic storage devices, or any suitable computer-readable storage
medium. The information may be accessed and operated upon according
to microprocessor 32 instructions and stored executable
instructions. In certain embodiments, calibration information may
be used in calculations for estimating of pressure in the cuff
based on measurements of pressure in the inflation line or
associated structures (e.g., the pilot balloon assembly). The
monitor 30 may be configured to provide indications of the cuff
pressure, such as an audio, visual or other indication, or may be
configured to communicate the estimated cuff pressure to another
device, such as the ventilator 22.
[0024] FIG. 2 is a perspective view of an exemplary tracheal tube
12 according to certain presently contemplated embodiments. It
should be understood that the embodiments discussed herein may be
implemented with any suitable airway device including a cuff 14,
such as a tracheal tube, an endotracheal tube, a tracheostomy tube,
a laryngeal mask, etc. Further, the embodiments disclosed herein
may be used with any medical device that includes an inflatable
component that is inflated via an inflation line that may include a
pilot balloon assembly. For example, the tube 12 includes a cuff 14
inflated via inflation lumen 18, which terminates in an opening 46
that is located within the inflated interior space 48 of the cuff
14. The interior space 48 is fluid communication with the pressure
transducer 20. The tracheal tube 14 is inserted in the patient such
that the distal end 50 and the cuff 14 are positioned within the
trachea (see FIG. 1) and the proximal end 52 is located outside of
the patient for connection via connector 54 to a ventilator. The
inflation lumen 18 includes an interior portion 60 and an exterior
portion 62 that extends away from the wall 64 of the tube 12 at an
opening 66.
[0025] The pressure transducer 20 may be any suitable pressure
sensor, such as a piezoelectric pressure sensor. In one embodiment,
the pressure sensor may incorporate a passive or active RFID
circuit that may be read wirelessly to convey pressure monitoring
information and/or calibration or identification information to the
monitor 30. In particular embodiments, a passive RFID component
without power connections or battery components may be
advantageous. The monitor 30 may incorporate an RFID readout
device. In one embodiment, the pressure transducer 20 may be part
of an assembly that includes a capacitor type pressure sensor and a
tuned antenna for a resonance frequency in a medical band, such as
a frequency in the 2.450 GHz center frequency or the 5.800 GHz band
(or higher). The sensor may be a CMUT (capacitive micromachined
ultrasonic transducer) sensor with a movable membrane fabricated
onto a silicon chip of a size suitable for the embodiments
discussed herein. In certain embodiments, a sweep of the
transmission frequency measures the resonant frequency of the
pressure transducer 20, which is a function of the cuff pressure.
The pressure transducer 20 may be capable of sensing pressures in a
range of 0 to 50 cm of H.sub.20.
[0026] The pressure transducer 20 may also be associated with an
information element, such as a memory circuit, such as an EPROM,
EEPROM, coded resistor, or flash memory device for storing
calibration information for the pressure transducer 20. The
pressure transducer 20 may also be part of an assembly that
contains certain processing circuitry for at least partially
processing signals from the pressure transducer 20 or for
interacting with any memory circuitry provided. When the pressure
transducer 20 communicates with the monitor 30, the information
element may be accessed to provide calibration information to the
monitor 30. In certain embodiments, the calibration information may
be provided in a barcode that may be scanned by a reader coupled to
the monitor 30. Alternatively, the pressure transducer 20 may
include a passive or active RFID circuit that may be read
wirelessly to convey pressure monitoring information and cuff
calibration information to the monitor 30.
[0027] The tube 12 and the cuff 14 are formed from materials having
suitable mechanical properties (such as puncture resistance, pin
hole resistance, tensile strength), chemical properties (such as
biocompatibility). In one embodiment, the walls of the cuff 14 are
made of a polyurethane having suitable mechanical and chemical
properties. An example of a suitable polyurethane is Dow
Pellethane.RTM. 2363-80A. In another embodiment, the walls of the
cuff 14 are made of a suitable polyvinyl chloride (PVC). In certain
embodiments, the cuff 14 may be generally sized and shaped as a
high volume, low pressure cuff that may be designed to be inflated
to pressures between about 15 cm H.sub.2O and 30 cm H.sub.2O.
However, it should be understood that the intracuff pressure may be
dynamic. Accordingly, the initial inflation pressure of the cuff 14
may change over time or may change with changes in the seal quality
or the position of the cuff 14 within the trachea.
[0028] The system 10 may also include a respiratory circuit (not
shown) connected to the endotracheal tube 12 that allows one-way
flow of expired gases away from the patient and one-way flow of
inspired gases towards the patient. The respiratory circuit,
including the tube 12, may include standard medical tubing made
from suitable materials such as polyurethane, polyvinyl chloride
(PVC), polyethylene teraphthalate (PETP), low-density polyethylene
(LDPE), polypropylene, silicone, neoprene, polytetrafluoroethylene
(PTFE), or polyisoprene.
[0029] FIG. 3 illustrates a tracheal tube 12 including a pilot
balloon assembly 72 at the proximal end 70 of the inflation line
18. In particular embodiments (see FIGS. 4-7), the pressure
transducer 20 may be associated with the pilot balloon assembly 72,
which may include a pilot balloon 74 configured to be in fluid
communication with the interior space 48 of the cuff 14. The pilot
balloon is coupled to the proximal end 70 of the inflation line at
a distal pilot balloon end 76. In the depicted embodiment, the
proximal pilot balloon end 78 is coupled to a valve 80. The valve
80 is configured to open to allow the transfer of fluid in or out
of the inflation system to inflate or deflate the cuff 14. For
example, the valve 80 may be configured to accommodate an inflation
syringe. In one implementation, insertion of the syringe may
depress a spring-loaded plunger, which opens the valve 80. Removal
of the syringe allows the plunger to return to a closed
configuration of the valve 80. It should be understood that other
configurations of a valve may also be incorporated into the pilot
balloon assembly 72.
[0030] In certain embodiments, the pressure transducer 20 may be
associated with an adapter assembly 90 configured to be inserted
into opening formed in the pilot balloon 74 as shown in FIG. 4. In
such an embodiment, a distal end 92 of the adapter assembly 90 may
be configured to couple to an opening formed in the proximal pilot
balloon end 78. A barb 94 or other retention feature may retain the
adapter assembly 90 on the pilot balloon 74 through an interference
fit with the proximal pilot balloon end 78. The adapter assembly 90
may be removable or, in embodiments, may be adhered to the pilot
balloon 74. For example, in other embodiments, the adapter assembly
90 may be adhered to, welded, heat bonded, or overmolded to the
pilot balloon assembly 72. A proximal opening 96 of the adapter
assembly 90 is coupled to a valve 98. The valve 98 may operate in a
manner similar to valve 80, allowing inflation or deflation of the
cuff 14 via a syringe. Accordingly, a tube 12 with the adapter
assembly 90 includes an integral cuff pressure transducer and is
capable of cuff inflation via a syringe. The depicted arrangement
may provide certain advantages over Y-type connectors that have
separate branches to connect to a syringe and a pressure
measurement device. By providing a single connection for a syringe
(and no connection for a pressure transducer 20, which is integral
to the adapter assembly 90), any confusion about which connector to
use is eliminated. Further, the adapter assembly 90 may be used in
conjunction with a standard pilot balloon 74 and inflation line 18,
keeping the same capability of qualitative assessment of the cuff
pressure by the clinician through squeezing the pilot balloon.
[0031] The adapter assembly 90 may define an enclosed space 100
that is in fluid communication with the interior of the pilot
balloon 74 and may be formed from a rigid or conformable material
that is substantially impermeable to ambient air. The adapter
assembly 90 may be any suitable shape, such as generally spherical
or elliptical. Because the cuff 14 may be inflated by transferring
air from an inflation syringe (or other fluid source) through the
interior enclosed space 100, the adapter assembly is not dead space
or does not result in an overall loss of fluid from the cuff 14.
Further, the inflation may be monitored via the pressure transducer
20 until a desired intracuff pressure is achieved. Fluid in the
inflation system (represented by arrow 102) equilibrates to a
constant pressure within the enclosed space 100, so that the
measured pressure in the adapter assembly 90 represents the
intracuff pressure.
[0032] The pressure transducer 20 may be coupled to the adapter
assembly so that one surface is exposed to the ambient air and one
surface is exposed to the enclosed space 100. The pressure
transducer 20 may include a flexible membrane with an electrode
surface. The interior pressure of the inflation system results in
movement or deflection of the membrane and its electrode relative
to a second electrode surface. The displacement generates an
alternating signal that is related to the size of the gap between
the electrode surface, the amount of displacement, and the
thickness of the membrane. The pressure transducer 20 may be
fabricated so that the displacement amount within expected cuff
pressures is tuned to a particular frequency. The signal may be
communicated via antennas 104. In the depicted arrangement, the
antennas 104 are diametrically opposed to one another on an
exterior surface of the adapter assembly 90. The pressure
transducer 20 may be coupled to the antennas 104, which are
configured to communicate with the patient monitor 30 in a selected
band. The antennas 104 may be arranged with respect to the adapter
assembly 90 to facilitate wireless communication at a desired
distance or at multiple angles. For example, in one embodiment, one
or more antennas 104 form a spiral or curved shape about the
pressure transducer 20 and are disposed to increase overall surface
coverage.
[0033] In an alternate arrangement, the pressure transducer 20 may
be coupled directly to the pilot balloon 74. As shown in FIG. 5,
the pressure transducer 20 may be embedded in or otherwise formed
within the pilot balloon wall 118. In one embodiment, the pilot
balloon 74 may be manufactured with openings formed to connect at
the distal pilot balloon end 76 to the inflation line and at the
proximal pilot balloon end 78 to the valve 80. An opening in the
balloon wall 118 may be cut to accommodate the pressure transducer
20, and the pressure transducer 20 may be positioned relative to
the pilot balloon 74 such that the interior surface 120 is within
the enclosed space of the pilot balloon and the exterior surface
122 is exposed to ambient air. Antennas 104a and 104b may be
wrapped about the exterior of the pilot balloon walls 118.
[0034] FIG. 6 depicts an implementation in which the pressure
transducer 20 is disposed on a substrate 130. The substrate 130 may
be rigid or conformable. In embodiments in which the substrate is
rigid, the balloon walls 118 remain conformable, which allows a
clinician to feel the stiffness to estimate the cuff pressure. The
substrate 130 may provide more surface area to attach to the
balloon walls 118. For example, the balloon walls may be glued or
otherwise adhered to an exterior surface 132 of the substrate (or,
in alternative implementation, to an interior surface 134). In
certain embodiments, the substrate 130 may be a two-part component
that clips the balloon walls 118 to enclose the interior of the
pilot balloon 74.
[0035] The substrate 130 may also provide a surface for one or more
antennas 104. In the depicted arrangement, the antennas 104a and
104b (see FIG. 7) are offset from one another on the exterior
surface 132 to avoid interference. In another embodiment, the
antennas 104a and 104b may be arranged in concentric spirals about
the pressure transducer 20.
[0036] The pressure transducer 20 may also be associated with the
inflation line 18. FIG. 8 is a perspective view of the tracheal
tube 12 including an inflation line adapter 150 that is positioned
in-line with the inflation line on the exterior portion 62. In such
an arrangement, the pilot balloon assembly 72 may be formed
according to conventional techniques. The inflation line adapter
150 connects or bridges a proximal portion 140 and a distal portion
142 of the inflation line 18. In one embodiment, the inflation line
adapter 150 may be coupled to the inflation line 18 by cutting the
inflation line 18 and inserting the inflation line adapter 150
between the two portions 140 and 142 that were previously adjacent
to one another.
[0037] FIG. 9 is a side view of the inflation line adapter 150. The
exterior surface 152 is sized and shaped to fit in-line with the
portions 140 and 142. The exterior surface 152 may be generally
barrel-shaped. In one embodiment, the exterior surface 152 defines
a widest diameter d1 is at least wider than the outer diameter d2
of the inflation line. Such an arrangement prevents the proximal
portion 140 and the distal portion 142 from being pushed towards
one another to cover the exterior surface 120 of the pressure
transducer 20. The inflation line adapter 150 may be retained in
place via barbed ends 154 and 156 and/or adhered to the inflation
line 18. For example, in other embodiments, the inflation line
adapter 150 may be adhered to, welded, heat bonded, or overmolded
to the inflation line 18. The barbed ends 154 and 156 are hollow so
that fluid, represented by arrows 157, is capable of moving through
an enclosed space 158 and into the inflation line 18.
[0038] The antenna wires 164a and 164b may be soldered or otherwise
coupled to the pressure transducer 20 and may run along the length
of the inflation line 18 to the pressure transducer 20 in any
suitable manner. For example, the antenna wires 164 may be embedded
(e.g., via extrusion) within the wall 162 of the tube inflation
line 18, may be run along the inside or the outside of the
inflation line 18, or may be printed on the inflation line 18. In
one embodiment, the antenna wires 164 embedded within the wall 162
of the inflation line 18 are exposed by stripping away a portion of
the inflation line wall 162 to reveal the wires 164, which are
soldered to the pressure transducer 20 and the coupling 170 may be
protected by epoxy.
[0039] In another embodiment, the pressure transducer 120 may be
integrated into a wall of the inflation line 18 such that at least
a portion of the pressure transducer 120 is exposed to ambient air
and a portion of the pressure transducer 120 is exposed to the
interior of the inflation line 18. The antenna wires 164 may
soldered to the pressure transducer and the coupling may be
protected with epoxy.
[0040] While the disclosure may be susceptible to various
modifications and alternative forms, specific embodiments have been
shown by way of example in the drawings and have been described in
detail herein. However, it should be understood that the
embodiments provided herein are not intended to be limited to the
particular forms disclosed. Indeed, the disclosed embodiments may
not only be applied to measurements of cuff pressure, but these
techniques may also be utilized for the measurement and/or analysis
of the tracheal pressure based on measurements of cuff pressure.
Rather, the various embodiments may cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the disclosure as defined by the following appended claims.
* * * * *