U.S. patent application number 17/513741 was filed with the patent office on 2022-02-17 for apparatus and method for locating fluid leaks in a reduced pressure dressing utilizing a remote device.
The applicant listed for this patent is KCI Licensing, Inc.. Invention is credited to Michael Bernard BEASLEY, Richard Marvin KAZALA, JR., Christopher Brian LOCKE, Larry Tab RANDOLPH, Timothy Mark ROBINSON, Malcolm G. THOMSON.
Application Number | 20220047795 17/513741 |
Document ID | / |
Family ID | 1000005940643 |
Filed Date | 2022-02-17 |
United States Patent
Application |
20220047795 |
Kind Code |
A1 |
THOMSON; Malcolm G. ; et
al. |
February 17, 2022 |
APPARATUS AND METHOD FOR LOCATING FLUID LEAKS IN A REDUCED PRESSURE
DRESSING UTILIZING A REMOTE DEVICE
Abstract
A system and method for performing tissue therapy may include
applying a reduced pressure to a tissue site of a patient. A fluid
parameter associated with applying a reduced pressure to the tissue
site may be sensed. An audible fluid leak location sound may be
generated in response to sensing the fluid parameter. The audible
fluid leak location sound may be altered in response to sensing
that the fluid parameter changes. By altering the audible fluid
leak location sound in response to sensing a change of the fluid
parameter, a clinician may detect location of a fluid leak at the
drape by applying force to the drape. The force applied to the
drape may be a clinician pressing a finger onto an edge of the
drape.
Inventors: |
THOMSON; Malcolm G.; (San
Antonio, TX) ; ROBINSON; Timothy Mark;
(Shillingstone, GB) ; KAZALA, JR.; Richard Marvin;
(San Antonio, TX) ; LOCKE; Christopher Brian;
(Bournemouth, GB) ; BEASLEY; Michael Bernard;
(Wimborne, GB) ; RANDOLPH; Larry Tab; (San
Antonio, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KCI Licensing, Inc. |
San Antonio |
TX |
US |
|
|
Family ID: |
1000005940643 |
Appl. No.: |
17/513741 |
Filed: |
October 28, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15740768 |
Dec 29, 2017 |
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PCT/US2016/040500 |
Jun 30, 2016 |
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17513741 |
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62186835 |
Jun 30, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 2205/3334 20130101;
A61M 1/90 20210501; A61M 2205/3576 20130101; A61M 1/74 20210501;
A61M 1/73 20210501; A61M 2205/15 20130101; A61M 2205/3344 20130101;
A61M 2205/6081 20130101; A61M 2205/505 20130101; A61M 2205/18
20130101 |
International
Class: |
A61M 1/00 20060101
A61M001/00 |
Claims
1.-27. (canceled)
28. A method for performing reduced pressure tissue therapy,
comprising: applying a reduced pressure to a tissue site of a
patient covered by a drape; sensing a sound pressure wave
propagating from the drape at a first location proximate the drape;
generating a first audio signal representing the sound pressure
wave and having amplitude and frequency components indicative of a
fluid leak at the first location when a fluid leak is present in or
proximate the drape; and generating an output signal when the
amplitude and frequency components indicate the presence of a fluid
leak at the first location.
29. The method according to claim 28, further comprising: computing
an amplitude average of the amplitude components of the first audio
signal over time; comparing the amplitude average of the first
audio signal to an amplitude threshold indicative of a fluid leak
at the first location; and generating the output signal indicating
the presence of a fluid leak at the first location if the amplitude
average is greater than the amplitude threshold.
30. The method according to claim 28, further comprising: sensing a
sound pressure wave at a second location proximate the drape to
sense a sound pressure wave propagating from the drape at the
second location; generating a second audio signal having amplitude
and frequency components indicative of a fluid leak at the second
location when a fluid leak is present in or proximate the
drape.
31. The method according to claim 28, further comprising: computing
a first amplitude average of the amplitude components of the first
audio signals over time and a second amplitude average of the
amplitude components of the second audio signal over time;
computing an amplitude difference between the second amplitude
average and the first amplitude average; and generating the output
signal indicating the presence of a fluid leak if the amplitude
difference is greater than an amplitude differential threshold
indicative of a fluid leak at the second location.
32. The method according to claim 28, further comprising: filtering
the frequency components of the first audio signal to pass filtered
frequencies corresponding to the sound pressure waves at locations
proximate the drape; comparing a frequency average of the filtered
frequencies of the first audio signal to a frequency threshold
indicative of a fluid leak at the first location; and generating
the output signal indicating the presence of a fluid leak at the
first location if the frequency average is greater than the
frequency threshold.
33. The method according to claim 28, further comprising: sensing a
sound pressure wave at a second location proximate the drape to
sense a sound pressure wave propagating from the drape at the
second location; generating a second audio signal having amplitude
and frequency components indicative of a fluid leak at the second
location when a fluid leak is present in or proximate the
drape.
34. The method according to claim 33, further comprising: filtering
the frequency components of the first audio signal and the second
audio signal to pass filtered frequencies corresponding to the
sound pressure waves at locations proximate the drape; computing a
first frequency average of the filtered frequencies of the first
audio signals and a second frequency average of the filtered
frequencies of the second audio signal; computing a frequency
differential between the second frequency average and the first
frequency average; and generating the output signal indicating the
presence of a fluid leak if the frequency differential is greater
than a frequency differential threshold indicative of a fluid leak
at the second location.
35. The method according to claim 28, further comprising generating
a graphical indicator indicative of the amplitude and frequency
components of the first audio signal at the first location while in
a leak location mode.
36. The method according to claim 28, further comprising generating
a graphical indicator indicative of the magnitude of the first
audio signal indicative of the severity of the fluid leak while in
a leak location mode.
37. The method according to claim 28, further comprising enhancing
propagation of the sound pressure wave at the first location by
resonating the sound pressure wave and generating the first audio
signal representing the resonated sound pressure wave.
38. The method according to claim 37, wherein the resonance is a
Helmholtz resonance.
39. A method for performing reduced pressure tissue therapy,
comprising: applying a reduced pressure to a tissue site of a
patient covered by a drape; sensing a fluid parameter associated
with applying the reduced pressure to the tissue site; determining
that a fluid leak exists in response to sensing a change in the
fluid parameter; generating a fluid leak signal in response to
determining that a fluid leak exists; sensing a sound pressure wave
propagating from the drape at a first location proximate the drape;
generating a first audio signal representing the sound pressure
wave and having amplitude and frequency components indicative of a
fluid leak at the first location when a fluid leak is present in or
proximate the drape; and generating an alarm signal when the
amplitude and frequency components indicate the presence of a fluid
leak at the first location.
40. (canceled)
41. A method for performing reduced pressure tissue therapy,
comprising: applying a reduced pressure to a tissue site of a
patient covered by a drape; sensing a sound pressure wave
propagating from the drape at a first location proximate the drape;
generating a first audio signal representing the sound pressure
wave; filtering the frequencies of the first audio signal to pass
filtered frequencies corresponding to the sound pressure waves at
locations proximate the drape; computing a frequency average of the
filtered frequencies of the first audio signal; comparing the
frequency average of the first audio signal to a frequency
threshold indicative of a fluid leak at the first location; and
generating an output signal indicating the presence of a fluid leak
at the first location if the frequency average is greater than the
frequency threshold.
42.-57. (canceled)
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/740,768, filed Dec. 29, 2017, which is a national stage
of International Patent Application No. PCT/US2016/040500, filed
Jun. 30, 2016, which claims the benefit, under 35 USC 119(e), of
the filing of U.S. Provisional Patent Application No. 62/186,835,
entitled "Apparatus and Method for Locating Fluid Leaks in a
Reduced Pressure Dressing Utilizing a Remote Device," filed Jun.
30, 2015, which are incorporated herein by reference for all
purposes.
TECHNICAL FIELD
[0002] This invention relates generally to an apparatus and method
of promoting tissue growth, and more specifically, an apparatus and
method for detecting fluid leaks of a dressing positioned at a
tissue site being treated by a reduced pressure delivery
system.
BACKGROUND
[0003] Tissue growth and wound healing of patients has been shown
to be accelerated through the use of applying reduced pressure to a
tissue site. Reduced pressure delivery systems operate to form such
a reduced pressure at a tissue site of a patient. This form of
wound healing can be readily integrated into a clinician's wound
healing procedures. Reduced pressure tissue therapy optimizes
patient care and decreases costs associated with treatment of
patients having traumatic and chronic wounds. Reduced pressure
therapy can be administered in hospitals, community settings, such
as assisted living complexes and convalescences homes, or homes of
patients.
[0004] Reduced pressure delivery to a wound or tissue site promotes
wound healing and/or tissue growth, in part, by removing infectious
materials and other fluids from the wound or tissue site. Reduced
pressure treatment further promotes tissue growth by imposing
forces on the tissue, thereby causing micro-deformation of the
tissue, which is believed to contribute to the development of
granulation tissue at the tissue site. The forces imposed on the
tissue site by the delivery of reduced pressure further encourages
improved blood flow at the tissue site, which further assists in
the growth of new tissue.
[0005] Reduced pressure delivery systems generally use a vacuum
pump to apply a reduced pressure via a reduced pressure conduit to
a tissue site. A manifold is often used at the tissue site to help
evenly distribute the reduced pressure. A drape is typically used
to cover the manifold and form a seal with surrounding tissue of
the tissue site to which the reduced pressure is being applied. In
order to maintain the reduced pressure at a relatively constant and
accurate reduced pressure to provide optimum tissue therapy, the
drape is to be interfaced and maintained with the healthy tissue
surrounding the tissue site, i.e., the peri-tissue, to minimize the
number and severity of the fluid leaks, such as air leaks. In the
event that a fluid leak results during installation of the drape or
during treatment, clinicians often find it difficult to isolate the
precise location of the fluid leak.
[0006] When a reduced pressure dressing is applied to a patient's
body, a visual inspection is made to confirm that the constituent
parts of the dressing such as, for example, the drape covering a
porous pad and a connector for providing the reduced pressure to
the porous pad, have been placed correctly to form a leak-free seal
over the tissue site. As the therapy device begins applying reduced
pressure in operation, the reduced pressure increases from ambient
pressure during a start-up period until a desired target pressure
is reached and maintained. The application of reduced pressure
causes the reduced pressure dressing to contract in response to the
increasing pressure. After the start-up period, a controller
regulates the reduced pressure during a therapy period based on the
therapy intended for treating the patient. Fluid leaks can occur
during the start-up and/or the therapy periods as a result of the
initial misplacement of these components or subsequent damage to
the drape itself. Locating such fluid leaks in reduced pressure
dressings can be time-consuming and difficult to correct.
[0007] Even though some drape material may be transparent so that
the wound and dressing can be seen by the clinician, visual
inspection through the drape material only helps to locate the
largest holes or leaks in the drape or other damage to the dressing
that is causing major leaks allowing air to leak into the tissue
site. While the clinical benefits of reduced-pressure therapy are
widely known, the complexity of reduced-pressure therapy can be a
limiting factor in its application and further development of
reduced-pressure systems which presents significant challenges to
manufacturers, healthcare providers, and patients.
SUMMARY OF THE INVENTION
[0008] To overcome the problem of locating fluid leaks at an
interface between a reduced pressure dressing and tissue of a
patient, new and useful systems, apparatuses, and methods for
detecting location of fluid leaks at the dressing of reduced
pressure delivery systems are set forth in the appended claims.
Illustrative embodiments are also provided to enable a person
skilled in the art to make and use the claimed subject matter.
[0009] One embodiment of a system for performing reduced pressure
tissue therapy may comprise a reduced pressure delivery system
configured to apply a reduced pressure provided by a reduced
pressure source to a tissue site, and a drape configured to be
positioned over the tissue site to maintain the reduced pressure at
the tissue site. The system may further comprise a mobile device
having a microphone operable to be positioned at a first location
proximate the drape to sense a sound pressure wave propagating from
the drape at the first location, and configured to generate a first
audio signal having amplitude and frequency components indicative
of a fluid leak at the first location when a fluid leak is present
in or proximate the drape.
[0010] In another embodiment of a system, the mobile device may be
further configured to compare an amplitude average of the amplitude
components of the first audio signal over time to an amplitude
threshold indicative of a fluid leak at the first location, and to
generate an output signal indicating the presence of a fluid leak
at the first location if the amplitude average is greater than the
amplitude threshold. The microphone may be operable to be
positioned at a second location proximate the drape to sense a
sound pressure wave propagating from the drape at the second
location, and configured to generate a second audio signal having
amplitude and frequency components indicative of a fluid leak at
the second location when a fluid leak is present in or proximate
the drape. The mobile device is further configured to compute a
first amplitude average of the amplitude components of the first
audio signal over time and a second amplitude average of the
amplitude components of the second audio signal over time, and to
compute an amplitude difference between the second amplitude
average and the first amplitude average. The mobile device may then
be configured to generate an output signal indicating the presence
of a fluid leak if the amplitude difference is greater than an
amplitude differential threshold indicative of a fluid leak at the
second location.
[0011] In another embodiment of the system, the mobile device may
be configured to filter frequency components of the first audio
signal to pass filtered frequencies corresponding to the sound
pressure waves at locations proximate the drape, to compare a
frequency average of the filtered frequencies of the first audio
signal to a frequency threshold indicative of a fluid leak at the
first location, and to generate an output signal indicating the
presence of a fluid leak at the first location if the frequency
average is greater than the frequency threshold. The microphone may
be operable to be positioned at a second location proximate the
drape to sense a sound pressure wave propagating from the drape at
the second location, and configured to generate a second audio
signal having amplitude and frequency components indicative of a
fluid leak at the second location when a fluid leak is present in
or proximate the drape. The mobile device may be further configured
to filter frequency components of the first audio signal and the
second audio signal to pass filtered frequencies corresponding to
the sound pressure waves at locations proximate the drape, and
further configured to compute a first frequency average of the
filtered frequencies of the first audio signal and a second
frequency average of the filtered frequencies of the second audio
signal. The mobile device may be configured further to compute a
frequency differential between the second frequency average and the
first frequency average, and further configured to generate an
output signal indicating the presence of a fluid leak if the
frequency differential is greater than a frequency differential
threshold indicative of a fluid leak at the second location.
[0012] One embodiment of a method for performing reduced pressure
tissue therapy may comprise applying a reduced pressure to a tissue
site of a patient covered by a drape, sensing a sound pressure wave
propagating from the drape at a first location proximate the drape,
and generating a first audio signal representing the sound pressure
wave. The method may further comprise computing an amplitude
average of the amplitudes of the first audio signal over time,
comparing the amplitude average of the first audio signal to an
amplitude threshold indicative of a fluid leak at the first
location, and then generating an output signal indicating the
presence of a fluid leak at the first location if the amplitude
average is greater than the amplitude threshold.
[0013] Another embodiment of a method for performing reduced
pressure tissue therapy may comprise applying a reduced pressure to
a tissue site of a patient covered by a drape, sensing a sound
pressure wave propagating from the drape at a first location
proximate the drape, and generating a first audio signal
representing the sound pressure wave. The method may further
comprise filtering the frequencies of the first audio signal to
pass filtered frequencies corresponding to the sound pressure waves
at locations proximate the drape, and computing a frequency average
of the filtered frequencies of the first audio signal. The method
may comprise further comparing the frequency average of the first
audio signal to a frequency threshold indicative of a fluid leak at
the first location, and then generating an output signal indicating
the presence of a fluid leak at the first location if the frequency
average is greater than the frequency threshold.
[0014] Yet another embodiment of a method for performing reduced
pressure therapy may comprise applying a reduced pressure to a
tissue site of a patient covered by a drape, sensing sound pressure
waves propagating from the drape at a first location proximate the
drape and a second location proximate the drape, and generating a
first audio signal and a second audio signal representing the sound
pressure waves. The method may comprise further computing a first
amplitude average of the amplitudes of the first audio signal over
time and a second amplitude average of the amplitudes of the second
audio signal over time, and then computing an amplitude difference
between the second amplitude average in the first amplitude
average. The method may comprise further comparing the amplitude
average of the first audio signal to an amplitude threshold
indicative of a fluid leak at the first location, and generating an
output signal indicating the presence of a fluid leak if the
amplitude difference is greater than an amplitude differential
threshold indicative of a leak at the second location.
[0015] And yet another embodiment of a method for performing
reduced pressure therapy may comprise applying a reduced pressure
to a tissue site of a patient covered by a drape, sensing sound
pressure waves propagating from the drape at a first location
proximate the drape and a second location proximate the drape, and
generating a first audio signal representing the sound pressure
waves and a second audio signal representing the sound pressure
waves. The method may comprise further filtering the frequencies of
the first audio signal and the second audio signal to pass filtered
frequencies corresponding to the sound pressure waves at locations
proximate the drape, and computing a first frequency average of the
filtered frequencies of the first audio signals and a second
frequency average of the filtered frequencies of the second audio
signal. The method may comprise further computing a frequency
differential between the second frequency average and the first
frequency average; and generating an output signal indicating the
presence of a fluid leak if the frequency differential is greater
than a frequency differential threshold indicative of a fluid leak
at the second location.
[0016] One additional embodiment of an apparatus for detecting
fluid leaks in a reduced pressure therapy system may comprise a
housing sized and adapted to be in the form of a hand-held tool, a
microphone positioned within the housing, a computing device
electrically coupled to the microphone, a display disposed on a
surface of the housing, and a communications interface. The
microphone may be operable to sense a sound pressure wave
propagating from a drape positioned over a tissue site, and
configured to generate a first audio signal and the computing
device may be configured to receive and process the first audio
signal to determine an existence of a fluid leak at the drape. The
display may be configured to provide output indicative of the
existence of a fluid leak, and the communications interface may be
configured to transmit and receive data related to the existence of
a fluid leak with a reduced pressure therapy system.
[0017] Objectives, advantages, and a preferred mode of making and
using the claimed subject matter may be understood best by
reference to the accompanying drawings in conjunction with the
following detailed description of illustrative embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] A more complete understanding of the apparatuses and methods
of the claimed inventions may be obtained by reference to the
following Detailed Description when taken in conjunction with the
accompanying Drawings wherein:
[0019] FIG. 1 is an illustration of an exemplary configuration of a
patient being treated using a reduced pressure delivery system;
[0020] FIG. 2 is an illustration of an exemplary drape covering a
tissue site to which reduced pressure is being applied by a reduced
pressure delivery system;
[0021] FIG. 3 is an illustration of an exemplary drape covering a
tissue site to which reduced pressure is being applied by a reduced
pressure delivery system;
[0022] FIG. 4 is a block diagram of an exemplary reduced pressure
delivery system configured to apply reduced pressure to a tissue
site and a mobile device configured to sense sound pressure waves
indicative of fluid leaks associated with a drape such as, for
example, the drape of FIG. 3;
[0023] FIGS. 5A and 5B are graphs of amplitudes of audio signals
sensed by a microphone of the mobile device of FIG. 4 to indicate
the detection of fluid leaks associated with the drape, wherein
FIG. 5A indicates that no leak is present and FIG. 5B indicates the
presence of a fluid leak;
[0024] FIGS. 6A and 6B are graphs of frequency response of the
audio signals that are examples indicating the detection of fluid
leaks associated with the drape, wherein FIG. 6A indicates that no
leak is present and FIG. 6B indicates the presence of a fluid
leak;
[0025] FIGS. 7A and 7B are perspective, schematic views of a
microphone resonator assembly that may be used in conjunction with
the microphone of a mobile device for detecting sound pressure
waves that may be analyzed to detect fluid leaks associated with a
drape;
[0026] FIG. 8 is a flow diagram of a method for detecting fluid
leaks of dressing positioned at a tissue site being treated by a
reduced pressure delivery system such as, for example, the system
of FIG. 4, including a peak signal detection module for detecting a
peak signal for comparison to a detection threshold;
[0027] FIG. 9 is a flow diagram of a peak signal detection module
for detecting a peak signal for comparison to a detection threshold
which may be used in the flow diagram of FIG. 8;
[0028] FIG. 10 is a screen shot of an exemplary graphical user
interface of a reduced pressure delivery system showing an
embodiment for enabling a clinician to select a "seal check"
function to locate fluid leaks that exist at the drape;
[0029] FIG. 11 is a screen shot of another exemplary graphical user
interface of a reduced pressure delivery system showing an
embodiment for enabling a clinician to select a mode for the
reduced pressure delivery system to determine whether any fluid
leaks exist at the drape;
[0030] FIGS. 11A-11H are depictions of exemplary indicators for
display on the graphical user interface of FIG. 11 to enable a
clinician to view while locating a fluid leak at a drape;
[0031] FIGS. 12A and 12B are flow charts of an exemplary process
for generating an output signal indicating the presence of a fluid
leak at a specific location when the amplitude or frequency
information of an audio signal is greater than a threshold value at
that location, or greater than the amplitude or frequency
information at another location, respectively;
[0032] FIG. 13 is a perspective, schematic view of an exemplary
leak detection assembly, including a leak detection tool, that may
be used for detecting sound pressure waves that may be analyzed to
detect fluid leaks associated with a drape; and
[0033] FIGS. 14A-14D are perspective, schematic views of another
exemplary leak detection tool, that may be used for detecting sound
pressure waves that may be analyzed to detect fluid leaks
associated with a drape.
DESCRIPTION OF THE EXAMPLE EMBODIMENTS
[0034] The following description of example embodiments provides
information that enables a person skilled in the art to make and
use the subject matter set forth in the appended claims, but may
omit certain details already well-known in the art. The following
detailed description is, therefore, to be taken as illustrative and
not limiting.
[0035] The example embodiments may also be described herein with
reference to spatial relationships between various elements or to
the spatial orientation of various elements depicted in the
attached drawings. In general, such relationships or orientation
assume a frame of reference consistent with or relative to a
patient in a position to receive treatment. However, as should be
recognized by those skilled in the art, this frame of reference is
merely a descriptive expedient rather than a strict
prescription.
[0036] With regard to FIG. 1, apparatus 100 for treating a patient
102 by providing reduced pressure therapy to a tissue site 104 of
the patient 102 is shown. The apparatus 100 comprises certain
reduced pressure dressing components (dressing components 105) and
a reduced pressure therapy system 106 that is fluidly coupled to
the tissue site 104 via the dressing components 105 to provide
reduced pressure treatment to the patient 102. The reduced pressure
therapy system 106 may include a reduced pressure delivery system
107 (delivery system 107) and a canister or container 108 for
collecting bodily fluids from the tissue site 104. The dressing
components 105 include a reduced pressure conduit 109 fluidly
coupled between the delivery system 106 to the tissue site 104, and
may also be coupled to the fluid container 108 for collecting
bodily fluids from the tissue site 104. Reduced pressure from the
conduit 109 may be distributed to the tissue site 104 via a reduced
pressure dressing or manifold (not shown) located at or within the
tissue site 104. The dressing components 105 may also include a
drape 110 that may be placed over the tissue site 104 and
distribution manifold to seal the distribution manifold at the
tissue site 104. The drape 110 may be constructed from a flexible
material that is impermeable to fluids including gases and liquids
to prevent air or other fluids from entering or exiting the tissue
site 104 during reduced pressure treatment. The dressing components
105 may also include a connector 112 that fluidly couples the
conduit 109 to the reduced pressure dressing or manifold through
the drape 110.
[0037] As used herein, the term "flexible" refers to an object or
material that is able to be bent or flexed. Elastomer materials are
typically flexible, but reference to flexible materials herein does
not necessarily limit material selection to only elastomers. The
use of the term "flexible" in connection with a material or reduced
pressure delivery apparatus in accordance with the principles of
the present invention generally refers to the material's ability to
conform to or closely match the shape of a tissue site. For
example, the flexible nature of a reduced pressure delivery
apparatus used to treat a bone defect may allow the apparatus to be
wrapped or folded around the portion of the bone having the
defect.
[0038] The term "fluid" as used herein generally refers to a gas or
liquid, but may also include any other flowable material, including
but not limited to gels, colloids, and foams. One example of a
fluid is air.
[0039] The term "impermeable" as used herein generally refers to
the ability of a membrane, cover, sheet, or other substance to
block or slow the transmission of either liquids or gas.
Impermeable may be used to refer to covers, sheets, or other
membranes that are resistant to the transmission of liquids, while
allowing gases to transmit through the membrane. While an
impermeable membrane may be liquid type, the membrane may simply
reduce the transmission rate of all or only certain liquids. The
use of the term "impermeable" is not meant to imply that an
impermeable membrane is above or below any particular industry
standard measurement for impermeability, such as a particular value
of water vapor transfer rate (WVTR).
[0040] The term "manifold" as used herein generally refers to a
substance or structure that is provided to assist in applying
reduced pressure to, delivering fluids to, or removing fluids from
a tissue site. A manifold typically includes a plurality of flow
channels or pathways that interconnect to improve distribution of
fluids provided to and removed from the area of tissue around the
manifold. Examples of manifolds may include, without limitation,
devices that have structural elements arranged to form slow
channels, cellular foams, such as open-desk cell foam, porous
tissue collections, and liquids, gels and foams that include or
cure to include flow channels.
[0041] The term "reduced pressure" as used herein generally refers
to a pressure less than the ambient pressure at a tissue site that
is being subjected to treatment. In most cases, this reduced
pressure will be less than the atmosphere pressure at which the
patient is located. Alternatively, the reduced pressure may be less
than a hydrostatic pressure of tissue at the tissue site. Although
the terms "vacuum" and "negative pressure" may be used to describe
the pressure applied to the tissue site, the actual pressure
applied to the tissue site may be significantly less than the
pressure normally associated with a complete vacuum. Reduced
pressure may initially generate fluid flow in the tube or conduit
in the area of the tissue site. As the hydrostatic pressure around
the tissue site approaches the desired reduced pressure, the flow
may subside, and the reduced pressure is then maintained. Unless
otherwise indicated, values of pressures stated herein are gage
pressures.
[0042] The term "scaffold" as used herein refers to a substance or
structure used to enhance or promote the growth of cells and/or the
formation of tissue. A scaffold is typically a three dimensional
porous structure that provides a template for cell growth. The
scaffold may be infused with, coated with, or comprised of cells,
growth factors, or other nutrients to promote cell growth. A
scaffold may be used as a manifold in accordance with the
embodiments described herein to administer reduced pressure tissue
treatment to a tissue site, as well as providing a template for
cell growth.
[0043] The term "tissue site" as used herein refers to a wound or
defect located on or within any tissue, including but not limited
to, bone tissue, adipose tissue, muscle tissue, neuro tissue,
dermal tissue, vascular tissue, connective tissue, cartilage,
tendons, or ligaments. The term "tissue site" may further refer to
areas of any tissue that are not necessarily wounded or defective,
but are instead areas in which it is desired to add or promote the
growth of additional tissue. For example, reduced pressure tissue
treatment may be used in certain tissue areas to grow additional
tissue that may be harvested and transplanted to another tissue
location.
[0044] The term "clinician" is used herein as meaning any medical
professional, user, family member of a patient, or patient who
interacts or interfaces with a delivery system.
[0045] Referring to FIG. 2, apparatus 200 for treating a patient
202 by providing reduced pressure therapy to a tissue site 204 of
the patient 202 is shown. The apparatus 200 comprises certain
reduced pressure dressing components (dressing components 205) and
a reduced pressure therapy system 206, which are substantially
similar to the apparatus 100 described above in FIG. 1 as indicated
by similar reference numbers. The reduced pressure therapy system
206 is fluidly coupled to the tissue site 204 via the dressing
components 205 to provide reduced pressure treatment to the patient
202. The reduced pressure therapy system 206 may include the
reduced pressure delivery system 107 (delivery system 107) and the
canister or container 108 for collecting bodily fluids from the
tissue site 204. The dressing components 205 of the apparatus 200
may include a reduced pressure conduit 209 fluidly coupled between
the delivery system 206 to the tissue site 204, and may also be
coupled to the fluid container 108 for collecting bodily fluids
from the tissue site 204. Reduced pressure from the conduit 209 may
be distributed to the tissue site 204 via a reduced pressure
dressing or manifold (not shown) located at or within the tissue
site 204. The dressing components 205 may also include a drape 210
that may be placed over the tissue site 204 and distribution
manifold to seal the distribution manifold at the tissue site 204.
The drape 210 may be constructed from a flexible material that is
impermeable to liquids and/or gases to prevent air or other fluids
from entering or exiting the tissue site 204 during reduced
pressure treatment. The dressing components 205 may also include a
connector 212 that fluidly couples the conduit 209 to the reduced
pressure dressing or manifold through the drape 210.
[0046] The drape 210 may be configured to form a visible outline
211 of the manifold when the drape 210 covers the distribution
manifold as a result of the distribution manifold being pressed
into the drape 210 to form the outline 211. The drape 210 covers
the tissue site 204, thereby helping to maintain a seal at the
tissue site 204 so that fluids, such as air, cannot enter or exit
the tissue site. Preventing fluids from entering or exiting the
tissue site 204 minimizes fluid leakage so that (i) a desired
amount of reduced pressure therapy is provided to the tissue site
204, (ii) the reduced pressure is delivered at a desired rate, and
(iii) the reduced pressure is maintained at a desired target
pressure for any desired amount of time. Minimizing fluid leakage
into the tissue site under the drape 210 also minimizes the chance
of infection from the air and other contaminants surrounding the
tissue site and facilitates growth of new tissue.
[0047] The process for dressing a wound at a tissue site comprises
positioning the distribution manifold adjacent the tissue site 204.
As part of the process, a clinician may cover both the distribution
manifold and the tissue site with the drape 210 and apply a force
to the drape 210 prior to and during operation of the delivery
system. By applying a force along the outer edges 215 of the drape
210, the clinician may create or otherwise improve the seal formed
between the drape 210 and peri-tissue 214 surrounding the tissue
site 204 at an intersection (not shown) between the drape 210 and
the peri-tissue 214. If the seal is not completely formed or a
fluid leak subsequently develops, the clinician may press a finger
216 along the outer edges 215 of the drape 210 to improve or
re-establish the seal at the intersection between the drape 210 in
the peri-tissue 214. Locating a fluid leak in the drape 210, e.g.,
a small hole or tear in the drape 210, or a fluid path between the
drape 210 and the peri-tissue 214 is often difficult in practice as
described above.
[0048] Referring to FIG. 3, apparatus 300 for treating a patient by
providing reduced pressure therapy to the tissue site 204 of the
patient is shown and comprises the dressing components 205 shown in
cross-section and a reduced pressure therapy system 206 of FIG. 2.
The drape 210 extends over a distribution manifold 302 and the
tissue site 204 to provide a seal so that the distribution manifold
302 is in fluid communication with reduced pressure conduit 209 as
described above. The seal is formed between the drape 210 and
peri-tissue 214 surrounding the tissue site 204 at an intersection
217 between the drape 210 and the peri-tissue 214. The drape 210
may be placed over or under the connector 212 and may be an
integral component with a connector 212. The drape 210 may also
adhere to the connector 212 with an adhesive, or welded or
otherwise sealed to the connector 212.
[0049] The reduced pressure conduit 209 is also in fluid
communication with a canister 308 and a delivery system 307 of the
reduced pressure therapy system 206, both of which may be similar
to the canister 108 and the delivery system 107 shown in FIG. 1.
The delivery system 307 may include a vacuum pump 310 and
electronic display 312. The electronic display 312 may include
control elements 314a-314n (collectively 314) that may be used by a
user or clinician operating the reduced pressure therapy system
206. In addition or alternatively, the electronic display 312 may
include a touch-screen 316 that enables the user or clinician to
interface with and operate the reduced pressure therapy system
206.
[0050] If a fluid leak develops at the intersection 217 between the
drape 210 in the peri-tissue 214 or anywhere in the drape 210, then
a fluid leak sensor (not shown) may generate and communicate a
fluid leak signal that may be provided to the delivery system 307.
The fluid leak signal may represent or be analogous to a fluid
parameter indicative of or responsive to an event wherein the fluid
leak exceeds a predetermined airflow level or threshold. A
processing unit (not shown) that may be a component of the delivery
system 307 may respond by generating a fluid leak alarm in an
audible and/or visual manner. For example, a buzzer, bell, recorded
message, or other audible sound may be generated to alert a
clinician that a fluid leak has occurred at the intersection 217
between the drape 210 and the peri-tissue 214. To locate the fluid
leak at the drape 210, the clinician may engage a fluid leak mode
that may be automatically or manually entered at the delivery
system 307. The fluid leak mode may be used to enable the clinician
to apply a force, such as pressing a finger around the outer edges
215 of the drape 210 or pressing the drape 210 around the
intersection 217. As the clinician applies force to the drape 210
at either point, the delivery system 307 may generate an audible
sound that changes in response to a change in the leak rate as a
result of pressure being applied to the specific location where the
fluid leak exists. The audible sound may be decreased in pitch or
volume, for example, to enable the clinician to identify the
location on the drape 210 so that the fluid leak may be
corrected.
[0051] Referring now to FIG. 4, apparatus 400 for treating a
patient by providing reduced pressure therapy to a tissue site of
the patient includes a reduced pressure therapy system 401. The
reduced pressure therapy system 401 comprises a delivery system 402
that is shown as applying reduced pressure to tissue site 404. The
delivery system 402 may include a controller 406 that includes a
processing unit 408. The controller 406 may also include an
electronic display device 407 and a receiver transmitter module
(not shown) including an antenna 409 for receiving and transmitting
signals for displaying information related to fluid parameters and
communicating with other devices such as, for example, mobile
devices. The processing unit 408 may include one or more
processors, logic, analog components, or any other electronics that
enable signals including information, such as fluid pressure at a
tissue site 404 or airflow out of the tissue site 404, to be
received by the receiver. The processing unit 408 may process the
information provided by such signals. For example, a fluid leak
signal may be received by the processing unit 408 and a fluid leak
alarm and/or fluid leak location process may be computed and
provided by the processing unit 408.
[0052] The delivery system 402 may further include a pump 410, such
as a vacuum pump, that may be driven by a motor 412. The motor 412
may be in electrical communication with the controller 406 and
respond to control signals 414 generated by the controller 406 to
adjust the desired speed of the pump 410 to generate and maintain
the desired pressure. The motor 412 may also provide information to
the controller 406 indicative of the pressure being applied to the
tissue site 404. The pump 410 is fluidly connected to a reduced
pressure conduit 416. The reduced pressure conduit 416 may include
an orifice 418 that operates as a relief valve. In parallel with
the orifice is a flow transducer 420 that may be configured to
determine flow rate of fluid passing through the reduced pressure
conduit 416. The flow transducer 420 is fluidly connected to the
reduced pressure conduit 416 and configured to generate a flow rate
signal 422 including information indicative of flow rate of a fluid
within the reduced pressure conduit 416.
[0053] A pump pressure transducer 424 may be connected to reduced
pressure conduit 416 to convert pressure in the reduced pressure
conduit 416 and communicate a pump pressure signal 426 including
information indicative of fluid pressure in the reduced pressure
conduit 416 to the controller 406. The pump pressure signal 426 may
be digital or analog. A pump release valve 428 may also be
connected to the reduced pressure conduit 416 and be configured to
release pressure from the reduced pressure conduit 416 in case of
an emergency situation or otherwise.
[0054] The reduced pressure therapy system 401 may further include
one or more filters 430a-430n (collectively 430) and a container
432 that are in fluid communication with the reduced pressure
conduit 416. The filters 430 may be in fluid communication with the
container 432, which is used to collect fluids from tissue site
404. The filters 430 may be configured to prevent fluids collected
in the container 432 from entering the reduced pressure conduit
416. The container 432 may further be in fluid communication with
reduced pressure conduit 434. Although shown as separate conduits,
the reduced pressure conduits 416 and 434 may be the same or
different material and have the same or different dimensions. The
reduced pressure conduit 434 may connect to or be in fluid
communication with a connector 436, which may be connected to a
distribution manifold 438 to distribute reduced pressure across the
tissue site 404. Drape 440 extends over the tissue site 404 on
peri-tissue 442 surrounding the tissue site 404 to form a seal at
an intersection 441 to generate and maintain reduced pressure at
the tissue site 404 as described above.
[0055] A feedback reduced pressure conduit 444 may pass through
container 432. A tissue release valve 446 may be connected to the
feedback reduced pressure conduit 444 to enable pressure to be
released at the tissue site 404 in response to a command signal 448
generated by the processing unit 408. The command signal 448 may be
generated by the processing unit 408 in response to the processing
unit 408 receiving a sensor signal, such as flow rate signal 422
crossing a threshold level as described above. Alternatively, the
command signal 448 may be generated in response to a clinician
selectively stopping the delivery system 402 via a user interface
(not shown). Other events, such as the completion of a treatment
cycle may cause the processing unit to generate the command signal
448 to activate the tissue release valve 446. In another example, a
tissue pressure transducer 450 may be used to convert pressure
sensed at the tissue site 404 and provide a feedback signal 452 to
the processing unit 408. In response to the processing unit 408
determining that pressure sensed at the tissue site 404 sensed is
above a threshold value, the processing unit 408 may communicate
command signal 448 to the tissue release valve 446 for release of
tissue pressure.
[0056] A speaker 454 may be in electrical communication with the
controller 406 to generate an audible sound as an alert along with
the information being provided to the clinician on the electronic
display device 407. In the event that the processing unit 408
determines that a fluid parameter, such as pressure at the tissue
site 404 or flow rate of fluid through the reduced pressure conduit
416 crosses a threshold value, the controller 406 may generate an
audio signal 456 that may be communicated to the electronic speaker
454 for providing an audible sound. For example, the processing
unit 408 may determine that a fluid leak exists at the tissue site
404 because the fluid flow rate increases above a predetermined
flow rate threshold level. In response to determining that the flow
rate level sensed by the flow transducer 420 has been exceeded, the
processing unit 408 may generate the audio signal 456 and
communicate an alert signal to the electronic speaker 454 to notify
a clinician that a problem exists. In another example, a sensor
such as tissue pressure transducer 450 may sense a fluid parameter
at the tissue site 404 and the processing unit 408 may determine
that the pressure at the tissue site 404 has decreased below a
desired level. Still yet, rather than directly sensing a fluid
parameter, an indirect measurement may be performed by measuring
power or voltage being applied to the motor 412 that may vary based
on the load on the pump 410 to determine approximate fluid flow.
The voltage may be a pulse width modulated voltage that varies
based on the duty cycle so that the duty cycle may be measured to
determine the approximate fluid flow. The processing unit 408 may
also communicate with a mobile device that directly senses a fluid
parameter and transmits such information back to the controller 406
to alert the clinician of a problem.
[0057] The processing unit 408 may be selectively programmed or
commanded to begin a fluid leak mode for enabling the clinician to
determine whether a fluid leak has developed at the drape 440 by
applying a force on the edges of the drape 440 or around the upper
surface of the drape 440 above the peri-tis sue 442. The processing
unit 408 may generate a continuous or discontinuous fluid leak
signal and drive the electronic speaker 454 to enable the clinician
to determine a location of the fluid leak at the drape 440.
Although the fluid leak mode is helpful for locating a fluid leak
at the drape 440, it should be understood that the fluid leak mode
may not enable the clinician to precisely locate the specific
location of fluid leaks proximate the drape 440. When referring to
fluid leaks proximate the drape 440, such leaks may include, for
example, fluid leaks extending through the drape 440 to the
distribution manifold 438, fluid passageways at the intersection
441 between the drape 440 and the peri-tis sue 442, or fluid leaks
between the drape 440 and the connector 436. The fluid leak mode
may also help a clinician locate a fluid leak at a conduit
connection or other location in the system. In one embodiment, a
connector (not shown) may be provided to cause the reduced pressure
conduits 416 and 434 to simulate operation with a drape seal that
is satisfactory (e.g., an acceptable level of fluid leakage) to
enable the clinician to locate fluid leaks at or within the reduced
pressure delivery system.
[0058] The apparatus 400 and/or the reduced pressure therapy system
401 may further comprise a computing device and a microphone
electrically and operatively coupled to the computing device. The
computing device may be selectively programmed to provide a leak
location mode (as distinguished from the fluid leak mode described
above) for enabling the clinician to identify the location of a
fluid leak proximate to the drape 440 by sensing sound waves or
audio waves generated by such leak and then providing a leak
location signal in response to the sound waves, without the
clinician having to go through the meticulous process of applying
force to the drape 440 as described above. The computing device
also may be electrically coupled to the processing unit 408 by
either wire or wireless means such as, for example, a Wi-Fi or
Bluetooth.RTM. connection. The microphone may be any type of an
acoustic-to-electric transducer or sensor that converts sound into
an electrical signal and can be electrically coupled to the
computing device by wire or wireless means such as, for example, a
Wi-Fi or Bluetooth.RTM. connection. More specifically, the
microphone may sense sound waves or audio waves generated by a
fluid leak and then provide a leak location signal in response to
the sound waves, which may indicate the existence and/or location
of the fluid leak.
[0059] The microphone is sufficiently small and mobile to allow
clinicians to more easily and conveniently (i) indicate whether a
fluid leak exists by providing a signal to the clinician such as,
for example, an alarm, and (ii) identify the specific location of
such fluid leak as the clinician moves the microphone along the
surface of the drape 440 tracing an outline of the drape 440 from
one location to another location on the drape 440. The leak
location mode may also use the microphone and computing device to
sense any background or ambient noise proximate the drape 440 which
may be filtered out to more accurately identify the occurrence and
location of a fluid leak. The leak location mode may also comprise
means for determining (i) a warm-up period during which the reduced
pressure pump 410 initially increases the reduced pressure to a
predetermined target pressure and (ii) operational periods during
which the reduced pressure pump 410 is engaged to maintain the
reduced pressure at the tissue site proximate the target
pressure.
[0060] The computing device may be, for example, a mobile device
which may be electrically and operatively coupled to the microphone
as described above or may include an integrated microphone for
sensing sounds generated by a fluid leak proximate the drape 440
and providing a leak location signal in response to the sound as
described above. The computer device or mobile device may be
programmed to implement the software algorithms shown in FIGS. 8,
9, 12A and 12B and described in the corresponding portions of the
specification for processing the leak location signal provided by
the microphone for identifying and locating fluid leaks. The mobile
device may be packaged or constructed as a single unit that
integrates the computer device and the microphone in a single
device such as, for example, a smart phone, tablet, or other device
that is capable of storing software applications, e.g., leak
detection application, programmed for a specific operating system
(e.g., iOS, Android, and Windows) that is used to read in and
interpret sound received by the microphone of the mobile device to
indicate changes in the relative sound pressure. The computing
device may also comprise a more stationary computer such as, for
example, a desktop computer operatively coupled to the microphone
that can be positioned proximate the surface of the drape 440 for
sensing sounds generated by a fluid leak proximate the drape 440 as
described above.
[0061] As indicated above, the mobile device may be a single unit
such as, for example, mobile device 460 that includes an integrated
microphone 464 used to sense sound pressure such as, for example,
sound wave 470 as indicated by arrow 471. The sound wave 470 may be
generated by a fluid leak such as, for example, a small hole 472 in
the drape 440 among other types of fluid leaks as described above.
The microphone 464 of the mobile device 460 senses the sound waves
470 when disposed proximate the drape 440 to facilitate the
presence and location of such fluid leaks. The mobile device 460
may also include an electronic display device 462 to provide visual
images to a clinician or patient including, for example, graphical
user interfaces (GUIs), haptics, and/or speakers as described above
that provide information relating to various alarms that a fluid
leak is present and changes in relative sound pressure waves that
are indicative of the size and/or location of the fluid leak sensed
by the microphone 464 and processed by the mobile device 460.
[0062] A clinician may use the microphone 464 of the mobile device
460 to detect sound pressure waves 470 generated by one of such
fluid leaks to more easily and immediately identify the location of
such fluid leak in-situ that may be corrected to more quickly
generate or maintain reduced pressure at the tissue site 404. The
mobile device 460 may also provide such information to the
controller 406 to alert a clinician who may be monitoring the
delivery system 402 several feet away from the tissue site 404. The
mobile device 460 may also provide such information to another
mobile device such as, for example mobile device 473 to remotely
monitor such information. The leak detection application on the
mobile device 460 may also be used to receive instructions from a
clinician using either the delivery system 402 or the other mobile
device 473. For example, the clinician may have received an audible
alarm from the speaker 454 of controller 406 and may inform the
patient that a serious fluid leak has occurred somewhere in the
dressing as described above and below in more detail. The clinician
might then instruct the patient to use the mobile device 460 to
specifically locate the fluid leak and determine the size of the
fluid leak or the airflow escaping from the fluid leak.
[0063] When the clinician uses the microphone 464 of the mobile
device 460 to detect sound pressure waves 470 generated by a fluid
leak, the audio signal received by the microphone 464 may be
sampled and analyzed to detect the presence and/or severity of a
fluid leak utilizing a leak detection application that is loaded on
a mobile device such as, for example, the mobile device 460. The
audio signal received by the microphone 464 may be sampled by the
leak detection application at a regular interval, i.e., the sample
rate, and then quantized to discrete values within a fixed range
such as, for example, a fixed range governed by a bit depth of
16-bits (i.e. pulse code modulation). The sample values may be, for
example, integers between -32768 and +32767 and the frequency of
the sample rate may be between 8 kHz and 44.1 kHz. To search for
fluid leaks, the clinician monitors the electronic display 462 of
the mobile device 460 and/or listens to the audio output signal
while slowly moving the mobile device 460 over the surface of the
drape 440 until a graphical or audible indicator signals the
location of a potential leak.
[0064] As the clinician moves the mobile device 460 over the
surface of the drape 440, the amplitude of the audio signals also
vary over time as represented audio signals 570 and 572 in FIGS. 5A
and 5B, respectively, which are typical of those present with a
typical apparatus 400 operating in a reasonably quiet room. Such
audio signals 570 and 572 may also have a frequency spectrum within
the dynamic frequency range of the microphone 464 or the frequency
range of human hearing (e.g., 20 Hz to 20 kHz) as represented by
the frequency responses 670 and 672, respectively, shown in FIGS.
6A and 6B. Referring back to FIGS. 5A and 5B, the first set of
audio signals 570 may correspond to a first location on the drape
440 where there are no leaks. The audio signals may be sampled and
analyzed, and may have amplitudes as shown in FIG. 5A indicating
that no fluid leak is present. The second set of audio signals 572
may correspond to a second location on the drape 440 when the
clinician moves the mobile device 460 to the second location, and
may have amplitudes as shown in FIG. 5B indicating that a fluid
leak is present. As can be seen, the amplitudes of the second set
of audio signals 572 increased compared to the amplitudes of the
first set of audio signals 570 as the clinician moved the mobile
device 460 over the surface of the drape 440 from the first
location to the second location where the presence of a fluid leak
was identified.
[0065] The amplitudes of the second set of audio signals 572 also
provide an indication of the severity of the fluid leak as well as
its specific location. For example, the clinician may set a
threshold value that is a maximum amplitude associated with a
maximum leakage to be tolerated as described above, i.e., an audio
amplitude threshold. The audio amplitude threshold may be used for
comparison to the amplitudes of the actual audio signals being
analyzed to provide an indication to the clinician or user that the
fluid leak it is sufficiently serious to require correction if the
audio amplitude threshold is exceeded. The clinician may also set a
threshold value that is the maximum difference in amplitudes
between the first location and the second location associated with
the maximum leakage to be tolerated, i.e., an audio amplitude
differential threshold. The audio amplitude differential threshold
may be used for comparison to the difference between the amplitudes
of the actual audio signals at two locations to provide an
indication to the clinician or user that the fluid leak is
sufficiently serious to require correction.
[0066] Referring back to FIGS. 6A and 6B, the frequency responses
670 and 672 of the audio signals 570 and 572, respectively, may
also indicate the presence of a fluid leak. More specifically, the
amplitudes of the audio signals 570 and 572 vary over time and may
be filtered and processed to generate the frequency responses 670
and 672. The first frequency response 670 corresponds to the first
location on the drape 440 as described above where there are no
leaks. The second frequency response 672 corresponds to the second
location on the drape 440 when the clinician moves the mobile
device 460 to the second location, and may have a magnitude
indicating that a fluid leak is present. As can be seen, the
magnitude of the second frequency response 672 identifies a
prominent group of frequencies between about 5 and 10 kHz where the
magnitude increased by approximately 30 dB when comparing the
frequency response 672 at the second location to the frequency
response 670 at the first location indicating the presence of a
fluid leak at the second location.
[0067] The magnitude of the second frequency response 672 also
provides an indication of the severity of the fluid leak as well as
its specific location. For example, the clinician may set a
threshold value that is a maximum magnitude associated with a
maximum leakage to be tolerated as described above, i.e., an audio
strength threshold. The audio strength threshold may be used for
comparison to the magnitudes of the frequency responses 670 and 672
to provide an indication to the clinician or user that the fluid
leak it is sufficiently serious to require correction if the audio
strength threshold is exceeded. The clinician may also set a
threshold value that is the maximum difference in magnitudes
between the first location and the second location associated with
the maximum leakage to be tolerated, i.e., a strength differential
threshold. The strength differential threshold may be used for
comparison to the difference between the magnitudes of the actual
frequency responses at the two locations to provide an indication
to the clinician or user that the fluid leak is sufficiently
serious to require correction.
[0068] Referring to FIG. 4, the mobile device 460 may include an
additional tool fitted with the microphone 464 to facilitate the
process of scanning for fluid leaks in the drape 440 or between the
drape 440 and the peri-tissue 442 as described above. Referring
more specifically to FIGS. 7A and 7B, the mobile device 460 is
shown in a perspective view as including a microphone aperture 474
that extends through the casing of the mobile device 460 through
which the microphone 464 receives the sound pressure waves 470. The
mobile device 460 may also comprise a microphone resonator 475
shown in an exploded and assembled view that may be fluidly coupled
to the microphone 464 through the aperture 474. The aperture 474
may have a diameter in the range of about 2 mm, for example, that
may also be smaller than the actual diameter of the microphone 464
embedded within the mobile device 460 adjacent the aperture 474.
The microphone resonator 475 comprises a resonator tube 476 that
may be mechanically coupled to the mobile device 460 to cover the
microphone aperture 474 so that the resonator tube 476 is
acoustically coupled to the microphone 464. The microphone
resonator 475 may further comprise a cylindrical rubber foot 477
having an aperture 478 extending axially through the cylindrical
rubber foot 477 to receive and support the resonator tube 476. The
resonator 475 may further comprise an adhesive washer 479 disposed
between the cylindrical rubber foot 477 and the casing of the
mobile device 460 to support the cylindrical rubber foot 477 and
the resonator tube 476 on the casing over the microphone aperture
474.
[0069] In one example embodiment of the microphone resonator 475,
the resonator tube 476 has a centerline that is aligned with the
center of the microphone aperture 474 and the microphone 464
embedded within the mobile device 460. The resonator tube 476 may
be constructed from polypropylene or similar material and may be
transparent to detect any blockages that might occur in use. The
resonator tube 476 may have a length and inside diameter suited to
acoustically match a specific frequency range of the sound pressure
waves 470 generated by a fluid leak in or around the drape 440 and
being sensed by the microphone 464. The frequency range of the
sound pressure waves 470 may lie within the frequency range of
human hearing (e.g., 20 Hz to 20 kHz) as described above. In one
example embodiment, the resonator tube 476 may have an inside
diameter in a range between about 2 mm and 6 mm. In another example
embodiment, the resonator tube 476 may have an overall length in a
range between about 30 mm and 50 mm. In yet another example
embodiment, the resonator tube 476 may have an overall length of
about 40 mm and an inside diameter of about 4 mm to match the
frequency range of human hearing (e.g., 20 Hz to 20 kHz) as
described above.
[0070] The microphone resonator 475 functions as an attachment to
the mobile device 460 to allow the mobile device 460 to reach into
tight crevices and creases formed by the drape 440 and functions
based on the phenomenon of air resonance within the resonator tube
476, i.e., Helmholtz resonance. In operation, air forced into the
resonator tube 476 increases the pressure within the cavity of the
resonator tube 476, but when the external force used to push the
air into the cavity is removed, the air within the cavity is pushed
out again due to the higher pressure. Typically, the air pressure
in the cavity decreases as a result of a fluid leak because the
negative pressure being applied through the distribution manifold
438 sucks air out of the cavity through the fluid leak associated
with the drape 440. When the cavity of the microphone resonator 475
is moved away from the fluid leak, air flows back into the cavity
which causes the air pressure in the cavity to return to a normal,
ambient pressure. Increasing the audio inlet path from the
microphone (i.e., the length of the resonator tube 476) shifts the
peaks of the frequency responses 670 and 672 downward in frequency
and increases the amplitude, thus aiding and enhancing the ability
of the microphone 464 to detect changes in signal energy as shown
in FIGS. 6A and 6B as described above. Increasing the inner
diameter of the resonator tube 476 may also increase the amplitude
of the signal energy, but to a lesser extent.
[0071] Referring to FIG. 8, a flow diagram or algorithm is shown as
one example of a leak detection application that may be a software
program implemented on a computer such as, for example, the mobile
device 460 as generally described above. The algorithm may embody a
method for detecting fluid leaks as shown commencing with the
detection of pressure sound waves at 800 using a microphone as
described above. The leak detection application determines whether
the microphone of a mobile device is enabled to detect pressure
sound waves at 801 and, if confirmed, then reads and samples audio
signals provided by the microphone at 802. The samples of the audio
signals are then processed through an adjustable high-pass filter
if enabled at 803 and 804 to remove lower frequency noise that
might be caused by human speech, e.g., a cut-off frequency of about
3.5 kHz. The output of the high-pass filter then cascades into an
adjustable low-pass filter if enabled at 805 and 806 in order to
remove high-frequency components if necessary. The high-pass filter
and the low-pass filter comprise a band-pass filter that can be
adjusted to remove ambient noise and narrowed to focus on the
specific frequency range where the frequency response of the fluid
leaks are expected.
[0072] The output values from the band-pass filter may then be
processed at 807 by calculating the RMS of the signals and then
computing the average which may be converted to determine the
magnitude or the signal strength (dB) of the pressure sound waves
such as, for example, the sound pressure wave 470, representing the
"energy" of the sound pressure wave. More specifically, the output
values from the band-pass filter may be numerically integrated to
approximate the RMS energy over the frequency window and then be
further smoothed to provide a rolling-average, e.g., 35 ms slow
"impulse" function or a 125 ms fast "exponential" time weighing
function as desired. A signal strength value (SS.sub.2) of the
sound pressure wave may be compared to a previously computed signal
strength value (SS.sub.1) at 808 by determining the difference
between them, i.e., a signal strength difference (.delta.SS).
Successive signal strength differences (.delta.SS) may be
determined in a similar fashion and stored in a database set for
subsequent processing to identify fluid leaks proximate a
drape.
[0073] In one example, the signal strength difference (.delta.SS)
may be compared to a predefined or adjustable signal strength
threshold (SST) at 809 such as, for example, the strength
deferential threshold described above, to determine whether a fluid
leak is present at 812, 813. If the signal strength difference
(.delta.SS) is greater than the signal strength threshold (SST), a
fluid leak is not only present, but also may be serious enough to
require correction as described above. The leak detection
application provides a signal indicating the detection of a fluid
leak at 814 on the electronic display of the mobile device (or via
other audio and/or haptic outputs as described above). This
detection process ends at 815 and is iterative as the microphone of
the mobile device is moved slowly across the surface of the drape.
Moreover, the fluid detection application may also allow for the
signal strength threshold (SST) to be adjusted manually or
dynamically to compensate for the changes in the ambient background
noise depending on the location of the drape being inspected.
[0074] In another example, the leak detection application may also
include a peak detection step shown at 810 that stores a block of
data representing a sample of signal-strength values (SS) and then
reads and processes the samples by comparing successive
signal-strength values (SS) in the block of data to determine
whether the values in the block of data are increasing toward a
peak value indicative of a fluid leak. Referring more specifically
to FIG. 9, a flow diagram or algorithm is shown as one example of a
peak detection application that may be a software program
implemented on a computer such as, for example, the mobile device
460 as generally described above. The peak detection algorithm may
embody a method for detecting peaks commencing at 820 with storing
a block of data representing a sample of a plurality of
signal-strength values (SS) as limited by a set of certain
conditions. For example, these conditions may include a maximum and
minimum number of data points in the sample that correlates with
the speed at which the microphone is being moved over the drape to
detect the leaks. The peak detection algorithm then reads
successive signal strength values (SS.sub.1 . . . SS.sub.N) in the
block of data at 821 to determine whether the current signal
strength value (SS.sub.x) to be read is greater than the previous
signal strength value (SS.sub.x-1) or signal strength values.
[0075] The peak detection algorithm may read the current signal
strength value (SS.sub.x) at 822 and then determine whether the
current signal strength value (SS.sub.x) is greater than a maximum
signal strength value (SS.sub.max) at 823 and, if yes, set or reset
the maximum signal strength value (SS.sub.max) to equal the current
signal strength value (SS.sub.x) at 824. If the current signal
strength value (SS.sub.x) is not greater than the maximum signal
strength value (SS.sub.max), the peak detection algorithm may then
determine whether the current signal strength value (SS.sub.x) is
less than a minimum signal strength value (SS.sub.min) at 825 and,
if yes, set or reset the minimum signal strength value (SS.sub.min)
to equal current signal strength value (SS.sub.x) at 826. Whether
or not the maximum and minimum signal strength values are set or
reset, the peak detection algorithm then determines whether the
successive signal strength values are increasing or decreasing in
order to detect signal strength peaks and troughs in the successive
signal strength values (SS.sub.1 . . . SS.sub.n) stored in the
block of data.
[0076] More specifically, the peak detection algorithm in one
example determines whether the current signal strength value
(SS.sub.x) is greater than the previous signal strength value
(SS.sub.x-1) at 830 in order to determine whether the signal
strength values (SS) are increasing or decreasing. In another
example, the peak detection algorithm may determine whether the
current signal strength value (SS.sub.x) is greater than a series
of previous signal strength values. The peak detection algorithm
may next determine which of two paths to take based on whether the
historic values appear to be increasing or decreasing in signal
strength at 830. The algorithm may initially be set to make an
arbitrary determination that the historic values are increasing,
but subsequently make such determination based on whether the path
previously taken went through 833 or 843. If the algorithm
determines that the signal strength values are increasing, the
algorithm next determines whether the current signal strength value
(SS.sub.x) is less than the maximum signal strength value
(SS.sub.max) at 831. If the answer is yes, then the direction of
the signal strength value (SS) is decreasing from the previous
signal strength value (SS.sub.x-1) indicating that a peak value has
been found. The minimum signal strength value (SS.sub.min) is set
to equal the current signal strength value (SS.sub.x) at 832
indicating a new leak at 833 so that the next reduction in the
magnitude of the signal strength value (SS) can be tracked.
[0077] The peak detection algorithm may then determine whether the
previous signal strength value (SS.sub.x-1), which inferentially is
the newly detected peak as described above, is bigger than any
previous signal strength value at 834. If yes, the peak detection
algorithm sets the previous signal strength value (SS.sub.x-1) as a
biggest signal strength value (SS.sub.B) that is used in subsequent
comparisons. If the previous signal strength value (SS.sub.x-1) is
not greater than the biggest signal strength value (SS.sub.B) at
834 or if the biggest signal strength value (SS.sub.B) is reset to
the previous signal strength value (SS.sub.x-1) at 835 or the
current signal strength value (SS.sub.x) was initially determined
not to be less than the maximum signal strength value (SS.sub.max)
at 831, then the peak detection algorithm determines whether all of
the signal strength values (SS.sub.n) have been read at 836. If
not, the peak detection algorithm resets the current signal
strength value (SS.sub.x) as the next signal strength value
(SS.sub.x+1) at 838 to be processed in a similar fashion commencing
at 822. However, if the peak detection algorithm determines that
all the signal strength values (SS.sub.n) have been read at 836,
the peak detection algorithm returns to the leak detection
application 800 described above to test the biggest signal strength
value (SS.sub.B) against the signal strength threshold (SST) at
809.
[0078] As indicated above, the peak detection algorithm determines
which path to take at 830 depending on whether the path last taken
went through 833 (new peak) or 843 (new trough) or no change. If
the algorithm determines that the signal strength values are
decreasing at 830, the algorithm next determines whether the
current signal strength value (SS.sub.x) is greater than the
minimum signal strength value (SS.sub.min) at 841. If the answer is
yes, then the direction of the signal strength value (SS) is
increasing from the previous signal strength value (SS.sub.x-1)
indicating that a trough value has been found. The maximum signal
strength value (SS.sub.max) is set to equal the current signal
strength value (SS.sub.x) at 842 indicating a new trough at 843 so
that the next increase in the magnitude of the signal strength
value (SS) can be tracked. If the answer at 841 is no or the
maximum signal strength value (SS.sub.max) is set to equal the
current signal strength value (SS.sub.x) at 843, then the peak
detection algorithm proceeds to determine whether all the signal
strength values (SS.sub.n) have been read and processed as
described above.
[0079] The electronic display device 462 may be programmed to
display a graphical user interface (GUI) displaying information
related to the analysis and processing of the audio signals for
detecting fluid leaks including identifying their location and
severity. Referring now to FIG. 10, a screen shot of a first GUI
902 may include a number of selectable graphical elements,
including a "settings" soft-button 906, "wound type" soft-button
908, "seal check" soft-button 910, and "history" soft-button 912. A
clinician or other user may select any of these functions (i.e.,
settings, wound type, seal check, or history), to cause the mobile
device 460 to present the user with another GUI for performing the
selected function. In addition, an "exit" soft-button 914 may be
available to the user to exit the current GUI 902. The seal check
soft-button 910 may be programmed to access the leak detection
application which operates as described above. It should be
understood that the GUI 902 is exemplary and that other and/or
alternative functions and selection elements may be provided by the
electronic display device 462 on the mobile device 460 to the
user.
[0080] An information region 916 on the GUI 902 may include
selectable graphical elements and display other information in
which the user may be interested. For example, a "help" soft-button
918 may be displayed to enable the user to receive help about the
delivery system 402 or particular functions currently being
displayed on the GUI 902. An "on-off" soft-button 920 may enable a
user to selectively turn the delivery system 402 on and off, and
status information 922 may notify the user of current status of the
delivery system 402. For example, the status information 922 may
indicate that the delivery system 402 is (i) operating in a
continuous therapy mode, (ii) is on, and (iii) is operating to
provide a reduced pressure of 200 mmHg. A "lock" soft-button 924
may enable the user to lock the GUI 902 to prevent an inadvertent
contact with the GUI 902 to cause the delivery system 402 to
respond.
[0081] Referring to FIG. 11, the mobile device 460 may display a
second GUI 932 on the electronic display device 462 in response to
a user selecting the "seal check" soft-button 910 on the GUI 902 of
FIG. 10. The GUI 932 may display a graphical indicator 934
indicative of the pressure and/or severity of a fluid leak. The
graphical indicator 934 may be a bar indicator having three levels,
including low, medium, and high thresholds for indicating the
signal strength difference (.delta.SS). The graphical indicator 934
may show a dynamic portion 936 that increases and decreases based
on the signal strength difference (.delta.SS) as determined by
moving the mobile device 460 from one location to another over the
drape 440 as described above. The height of the dynamic region 936
may indicate, for example, the amount of a fluid leak currently
being sensed at a tissue site. Although the graphical indicator 934
may be helpful to a clinician for determining the location of a
fluid leak, e.g., a fluid leak associated with the drape 440
covering the tissue site 404 and the distribution manifold 438, the
graphical indicator 934 may be difficult to view if the electronic
display device 462 were a component of the reduced pressure therapy
system 401 located several feet away from the drape where the
clinician is attempting to locate a fluid leak as opposed to being
displayed on the mobile device 460.
[0082] So that the clinician may more easily locate the fluid leak
at the drape, the mobile device 460 may generate an audible sound
or other graphical or haptic output indicative of the location of a
fluid leak sensed by the microphone 464 of the mobile device in
conjunction with the level of a particular signal strength
difference (.delta.SS) sensed by the mobile device 460. The
clinician may select a "seal audio" soft-button 938 to toggle or
mute and unmute an audible fluid leak location sound off and on
(i.e., mute and unmute). The audible fluid leak location sound may
be altered in response to the changes of the magnitude of the
signal strength difference (.delta.SS). For example, if pressure at
the tissue site increases in response to moving the mobile device
460 from one location to another on the drape, the audible fluid
leak location sound may be altered to indicate to the clinician
that the fluid leak has been located.
[0083] The audible fluid leak location sound may change in
frequency, volume, or pitch. Alternatively, a "Geiger counter"
sound may be produced during the seal check, where a tone speed
increases or decreases depending upon the severity of the fluid
leak. For example, if the clinician is "cold" with respect to the
location of the fluid leak, the Geiger counter sound may beep
slowly. When the clinician approaches near the fluid leak of the
drape, then the Geiger counter sound may increase as the mobile
device gets closer to the fluid leak. In another embodiment, the
audible fluid leak location sound may be a recorded message, such
as "cold," "warmer," and "hot." In another example, a "water
dripping" sound may be generated to represent that a fluid leak
(e.g., air leak) exists. It should be understood that nearly any
sound may be utilized to indicate the presence and/or severity of a
fluid leak to help the clinician locate the fluid leak and assess
the severity to determine whether corrective measures are
necessary. Because the microphone of a mobile device and even a
human ear are more sensitive than human eyes, the use of an audible
sound to indicate the presence and/or severity of a fluid leak may
enable the clinician to more easily correct the fluid leak at the
drape than a graphical indicator.
[0084] Regarding FIG. 11A, a bar indicator 940a may display a
dynamic region 942a indicative of a level of the signal strength
difference (.delta.SS). The dynamic region 942a is shown to be
within a "low" fluid leakage level and have a corresponding pattern
(e.g., lightly shaded) or color (e.g., green). A threshold level
indicia 944 may be representative of a signal strength threshold
(SST) level that may be preset by a clinician or manufacturer of
the mobile device 460, where an alarm or other response may be
generated in response to the fluid leakage parameter crossing the
signal strength threshold (SST) level. Referring to the bar
indicator 940b in FIG. 11B, the dynamic region 942b increases above
the threshold level indicia 944, thereby causing an alarm to be
generated and the delivery system 402 to enable a clinician to
identify the location of the fluid leak and assess the relative
severity of the fluid leak. The dynamic region 942b may be changed
in pattern (e.g., medium shade) or color (e.g., yellow) to
represent that the fluid parameter is currently in the medium
range. If, for example, the fluid parameter increases to cause the
dynamic region 942 to enter into a high range, then the dynamic
region 942 may be changed in pattern (e.g., solid color) or color
(e.g., red). Other graphical features may be used, such as flashing
or otherwise, to provide the clinician with visual information to
make it easier to determine the urgency for corrective measures for
sealing the leak.
[0085] Referring to FIG. 11C, a time sequence 946a is shown to
include a number of graphic bars 948a-948n over a time period
between time T.sub.0 and T.sub.n. Graphic bars 948a-948n indicate
that the signal strength difference (.delta.SS) is at a low fluid
leakage level as the mobile device is moved over the drape from one
location to another. However, as shown in FIG. 11D, graphic bar
948n+4 at time T.sub.n+4 increases above the signal strength
threshold (SST) as represented by the threshold level indicia level
950. Referring to FIGS. 11E and 11F, a signal strength difference
(.delta.SS) level is shown alpha-numerically in display fields 952a
and 952b, respectively. As shown, the fluid leakage rate is at "1"
which represents a low level leakage, and "5" which represents a
higher level leakage. In one embodiment, ranges between 0-3 may
represent a low level leakage, 4-6 may represent a medium level
leakage, and 7-10 may represent a high level leakage. Each level of
leakage may represent a corresponding flow rate and the digits may
change color (e.g., green, orange, and red) depending on the fluid
leakage level. In an alternative embodiment, letters, such as
"A"-"F," may be displayed.
[0086] Referring to FIGS. 11G and 11H, pie charts 954a and 954b,
respectively, may be displayed that show leakage levels 956a and
956b, respectively, that indicate fluid leakage during operation of
a tissue treatment system. One or more threshold levels 958 may be
shown and used to identify when a fluid leakage exceeds the
threshold, thereby causing a fluid leakage alarm to be initiated.
If multiple threshold levels are used, each may represent a
different leakage level (e.g., low, medium, or high) and may cause
a different alarm, audible and/or visual, to be initiated.
Depending on the level of the fluid leakage rate, the color or
pattern may change. In addition, an audible sound may be altered in
response to the fluid leakage rate increasing or decreasing above
or below a threshold level.
[0087] Referring to FIG. 12A, a process 960 for determining
location of a fluid leak is provided. The process 960 starts at
step 962, where a reduced pressure may be applied to a tissue site.
At step 964, a fluid parameter associated with the reduced pressure
may be sensed. The fluid parameter may include a fluid flow rate,
fluid pressure, or otherwise. In one embodiment, the fluid
parameter is sensed at the tissue site. In another embodiment, the
fluid parameter is sensed in a reduced pressure conduit of the
delivery system. It should be understood that the fluid parameter
may be sensed by any type of sensor that is sensitive enough to
sense changes in the fluid parameter that are meaningful to a
clinician when attempting to locate and seal a fluid leak. For
example, a fluid flow transducer may be configured to sense changes
in fluid flow rate between approximately 0.1 liters per minute and
2.0 liters per minute and have a resolution of approximately 0.01
liters per minute.
[0088] At step 966, a fluid leak signal may be generated in
response to sensing the fluid parameter. The fluid leak signal may
be one of a variety of different visual graphics or audible sounds.
For example, continuous tones with varying frequency, pitch or
volume, for example, may be utilized. Alternatively, discrete tones
with varying length or frequency may be utilized. Still yet,
recorded messages, sounds, or otherwise may be utilized. It should
be understood that any sound or combination of sounds may be
utilized as an audible fluid leak location sound. At step 970, a
sound pressure wave propagating from the drape of a dressing may be
sensed at a first location proximate the drape. At step 972, a
first audio signal may be generated representing the sound pressure
wave. At step 974, an amplitude average of the amplitudes of the
first audio signal may be computed. At step 976, the amplitude
average of the first audio signal may be compared to an amplitude
threshold indicative of a fluid leak at the first location. And
then at step 978, an output signal indicating the presence of a
fluid leak at the first location may be generated if the amplitude
average is greater than the amplitude threshold.
[0089] Alternatively, the frequencies of the first audio signal may
be filtered to pass those frequencies, i.e. filtered frequencies,
corresponding to the sound pressure waves at locations proximate
the drape. A frequency average of the filtered frequencies of the
first audio signal may be computed and compared to a frequency
threshold indicative of a fluid leak at the first location so that
an output signal indicating the presence of a fluid leak at the
first location may be generated if the frequency average is greater
than the frequency threshold.
[0090] Referring to FIG. 12B, another process 980 for determining
location of a fluid leak is provided. The process 980 starts at
step 982, where a reduced pressure may be applied to a tissue site.
At step 984, a fluid parameter associated with the reduced pressure
may be sensed. The fluid parameter may include a fluid flow rate,
fluid pressure, or otherwise. It should be understood that the
steps are substantially similar to steps 960, 962 and 964 described
above. At step 986, a fluid leak signal may be generated in
response to sensing the fluid parameter. The fluid leak signal may
be one of a variety of different visual graphics or audible sounds
as described above with respect to step 966. At step 990, a sound
pressure wave propagating from the drape of a dressing may be
sensed at a first location and the second location proximate the
drape. At step 992, a first audio signal and a second audio signal
may be generated representing the sound pressure waves. At step
994, an amplitude average of the amplitudes of the first audio
signal and the second audio signal may be computed. At step 996, a
difference between the average values of the first location and the
second location may be computed, and then the difference may be
compared to an amplitude differential threshold at step 997. And
then at step 998, an output signal indicating the presence of a
fluid leak may be generated if the amplitude average is greater
than the amplitude differential threshold.
[0091] Alternatively, the frequencies of the first audio signal and
the second audio signal may be filtered to pass those frequencies,
i.e. filtered frequencies, corresponding to the sound pressure
waves at locations proximate the drape. A frequency average of the
filtered frequencies of the first audio signal and the second audio
signal may be computed and compared to a frequency differential
threshold indicative of a fluid leak so that an output signal
indicating the presence of a fluid leak may be generated if the
frequency average is greater than the frequency threshold at the
second location.
[0092] The principles of the present disclosure may also be applied
to embodiments which do not require the use of a mobile device,
such as mobile device 460. For example, in place of a mobile
device, a separate hand-held portable device may be employed, which
may be compatible and used with existing negative-pressure therapy
systems, such as the V.A.C..RTM. systems, commercially available
from Kinetic Concepts Inc., of San Antonio, Tex. USA. Thus,
referring now to FIG. 13, an example, illustrative embodiment of a
leak detection assembly 1002 is shown. In this example embodiment,
the leak detection assembly 1002 may include a leak detection tool
1004 and a cable 1006. The cable 1006 may be connected at one end
to the leak detection tool 1004 and at the other end to a reduced
pressure therapy system, and may allow for electrical communication
between the leak detection tool 1004 and the reduced pressure
therapy system. The cable 1006 may include a connector 1008, which
may be for operatively connecting the cable 1006 to a connection
port on a delivery system, such as delivery system 402. For
example, the connector 1008 may be a USB connector for connection
to a USB port. In such example embodiments, the software described
above with respect to other example embodiments may be operative
for controlling functions of the leak detection tool 1004. For
example, the software may be resident on the delivery system 402,
and more specifically in the controller 406.
[0093] FIG. 14 collectively provides multiple views of an
alternative example embodiment of a hand-held version of the leak
detection tool 1004. Referring first primarily to FIG. 14A, the
leak detection tool 1004 may include a body 1006, which may be in
the form of a wand-like housing for components of the leak
detection tool 1004. For example, the body 1006 of the leak
detection tool 1004 may include a handle portion 1008, a guidance
region 1010, a sound energy collector 1012, and a display 1014. In
some embodiments, the guidance region 1010 may include one or more
contours for allowing a user to obtain a more controlled grip with
a thumb or other finger. Referring now also to FIG. 14B, the leak
detection tool 1004 may further include a port 1016, which may
allow connection to a cable, such as cable 1006 of FIG. 13, which
may be used to electrically couple the leak detection tool 1004 to
the delivery system 402 of the reduced pressure therapy system 401.
For example, the port 1016 may be a USB port, mini-USB port,
micro-USB port, or any other type of suitable port. Alternatively
or additionally, the port 1016 may include a wireless transceiver,
for wirelessly communicating with such-enabled delivery systems.
For example, the port 1016 may include a transceiver capable of
communications via Bluetooth.RTM., ZigBee.RTM., WI-FI, cellular, or
other signal protocol. Additionally, embodiments of the leak
detection tool 1004 which may communicate wirelessly with a therapy
unit may further include a battery to allow for cordless operation
of the leak detection tool 1004. In addition to increased
convenience for a user, cordless operation may also allow use with
present or future therapy systems that may not include USB or other
wired connection ports.
[0094] Referring now primarily to FIGS. 14C-14D, a bottom, or
underside, view of the leak detection tool 1004 is shown. In FIG.
14C, the underside or inside cavity of the sound energy collector
1012 including a portion of a microphone 1018 may be seen. In
addition to the possible types and configurations of microphones
previously discussed with respect to other embodiments, the
microphone 1018 may be an ultrasonic microphone. Additionally, as
shown in FIG. 14D, the sound energy collector 1012 may be attached
to a swivel base 1020, which may be part of the body 1006 of the
leak detection tool 1004. The swivel base 1020 may allow for the
sound energy collector 1012 to pivot as it comes into contact with
a surface, to provide good reception of sound energy that may
propagate from the surface, such as a wound drape, while also
providing ease of use.
[0095] Referring again to FIG. 14A, the display 1014 of the body
1006 of the leak detection tool 1004 may include one or more
indicators, such as lights, for alerting a user when the leak
detection tool 1004 has identified a possible area of a test
surface, such as a wound drape, where a leak may be present. For
example, in some embodiments, the display 1014 may include one or
more LEDs, which may be part of a filtering and detection circuitry
positioned within the body 1006 of the leak detection tool 1004.
The LEDs may illuminate and display different colors depending on
the input detected from the test surface. In one illustrative
embodiment, an LED of the display 1014 may emit a green light if no
leak conditions are detected, a yellow light if a potential leak is
detected, and a red light if a likely leak source has been
identified. As previously discussed to some extent, the software
for operation of the leak detection tool 1004 may be either stored
on a controller, such as controller 406, of the delivery system
402, or on a circuitry associated with a processor of the leak
detection tool 1004.
[0096] The previous description is of preferred embodiments for
implementing the invention, and the scope of the invention should
not necessarily be limited by this description. The scope of the
present invention is instead defined by the following claims.
* * * * *