Note: Descriptions are shown in the official language in which they were submitted.
CA 02658886 2014-03-27
DESCRIPTION
PATIENT SUPPORT WITH WELDED MATERIALS
Field of the Invention
The present disclosure relates generally to systems and methods for supporting
patients or other persons, and more particularly but not by way of limitation
to systems
and methods for supporting patients or other persons with materials that have
been
coupled or joined by welding.
Background
Patient support surfaces, including therapeutic surfaces, are common in
medical settings such as hospitals, clinics, and patients' homes, among other
places.
Some surfaces (commonly referred to as "low air loss" surfaces) include
inflatable
enclosures that flow air through air permeable materials adjacent to the
patient in an
effort to prevent or treat pressure ulcers.
The treatment and/or prevention of pressure ulcers are serious and expensive
issues in the health care industry. Pressure ulcer development is related, in
part, to
the accumulation of heat and perspiration on the skin. Heat and moisture
increase
skin susceptibility to the damaging effects of pressure and shear and decrease
the
resiliency of the epidermis to external forces. Ongoing compressive forces on
skin
tissues are known to promote ischemia with subsequent development of pressure
ulcers. Therefore, controlling the microclimate of the skin and providing a
quality
patient support system appear to be necessary to prevent pressure ulcers.
Low-air-loss (LAL) broadly refers to a system comprising a mattress casing, a
vapor permeable coverlet with or without lofting or cushioning material, and
an air
delivery system to move air under the coverlet and, in
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some cases, to leak through the coverlet. Some LAL mattress systems
function as integral parts of patient support systems; whereas, others are not
actively coupled.
Currently, low-air-loss (LAL) mattress systems are the most prevalent
tools used for pressure ulcer treatment and prevention. LAL mattress
systems were developed and are used in the belief that they help to control
the microclimate of the skin. These systems have been found to be highly
effective in treating and/or preventing pressure ulcers.
Certain support surfaces comprise more than one material, with each
material having different air, vapor, and liquid permeability properties. For
example, it may be desirable to have a vapor permeable material adjacent to
the patient's skin to allow moisture vapor to transfer away from the patient
and
into the support surface. It may also be desirable to have an air permeable
material adjacent to the patient's skin to allow air to flow proximal to the
patient and assist in removing moisture vapor from the patient and the support
surface. Furthermore, it may be desirable for portions of the support surface
to be air impermeable in order to restrict air flow and minimize power
requirements and noise levels for the support system. For hygienic reasons,
it may be desirable that the support surface comprise a liquid impermeable
material.
LAL mattresses typically include a foundation of a series of
interconnected air cells that allow air to flow through and exit the mattress.
Other common elements include an adjustable pump that can maintain air
inflation of the air cells. In addition to the mattress, the LAL mattress
system
also includes the coverlet (waterproof and/or vapor permeable), and coverlet
lofting material (e.g., quilted polyester fabric batting) that attach over the
mattress. The coverlet is typically made of one or more materials that are
permeable to moisture, is impermeable to bacteria, and is waterproof.
Coverlets also function to prevent excessive loss of body heat, have high
moisture vapor permeability to minimize/prevent the accumulation of
perspiration on the skin, and have high air porosity for removal of excessive
body heat through a continuous airflow provided by the LAL mattress.
Together, the LAL mattress and the coverlet form the LAL mattress system.
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The LAL mattress can further include a fabric cover over the foundation
(i.e., the air cells). In some cases, this fabric cover is formed from a GORE-
TEX fabric that is formed integrally with the air cells. The GORE-TEX fabric
is liquid impermeable and has significantly higher air-permeable and vapor
permeable characteristics as compared to urethane-backed nylon materials
used in other mattresses. The GORETEX fabric moisture vapor transfer
characteristics help to prevent or speed up healing of pressure ulcers in
patients by reducing the amount of moisture buildup on the skin and by
helping to keep patients cooler by allowing body heat to more easily escape.
It is therefore desirable to construct a support surface from different
types of materials. As a result, it is often necessary to couple or join
different
types of material used to form the support surface.
Summary
Exemplary embodiments of the present disclosure are directed to
apparatus, systems, and methods to support a patient or other person.
Exemplary embodiments comprise a first air impermeable material welded to
a second material that is air permeable and liquid impermeable. In exemplary
embodiments, the first material is liquid and vapor impermeable and the
second material is vapor permeable. In
exemplary embodiments, an
inflatable enclosure is formed from a sheet of the first material with an
aperture, and the second material covers a portion of the aperture. In other
exemplary embodiments, an inflatable enclosure may be formed by several
individual panels of the first material welded to a panel of the second
material.
Exemplary embodiments comprise a support member comprising an
inflatable enclosure having a first material and a second material, wherein
the
first material is substantially air impermeable, the second material is air
permeable and substantially liquid impermeable, and the second material is
welded to the first material. In exemplary embodiments, the first material
comprises an aperture and the second material covers a portion of the
aperture. In other exemplary embodiments, the second material is high
frequency (HF) welded to the first material. In
still other exemplary
embodiments, the second material is vapor permeable. Certain exemplary
embodiments comprise an internal baffle. In
still other exemplary
embodiments, the first material is urethane. Certain exemplary embodiments
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comprise an opening configured to be coupled to a source of pressurized
fluid.
Other exemplary embodiments comprise an apparatus for supporting a
person, comprising: a sheet comprising a first material, wherein the first
material is substantially air impermeable; an aperture in the sheet; a second
material covering the aperture, wherein the second material is air permeable
and substantially liquid impermeable and the second material is welded to the
first material. In certain exemplary embodiments, the sheet comprises a first
end, a second end, a first side and a second side; the first side is coupled
to
the second side; the first end is sealed; and the second end is sealed, so
that
the sheet is configured to form an elongated inflatable enclosure. In
exemplary embodiments, the sheet is configured to form a generally
cylindrical enclosure when inflated.
Certain exemplary embodiments
comprise an internal baffle, wherein the elongated inflatable enclosure has a
cross-section having a height and a width, wherein the height is greater than
the width. In exemplary embodiments, the second material is high frequency
(HF) welded to the first material. In certain exemplary embodiments, the
second material is vapor permeable and/or the first material is urethane. In
certain exemplary embodiments, the sheet comprises an opening configured
to be coupled to a source of pressurized fluid.
Other exemplary embodiments comprise a support system comprising:
a plurality of first and second support members, wherein the first support
members are a first height and comprise a first material that is substantially
air
impermeable and the second support members are a second height and
comprise a second material that is air permeable and substantially liquid
impermeable. In exemplary embodiments, the first height is greater than the
second height and a second support member is located between two first
support members. In exemplary embodiments, the second material is vapor
permeable. In certain exemplary embodiments, the first support members
comprise a vapor permeable and liquid impermeable third material. In other
exemplary embodiments, a first source of pressurized fluid is coupled to the
first support member and coupled to the second support member. In still
other exemplary embodiments, a first source of pressurized fluid is coupled to
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the first support member and a second source of pressurized fluid is coupled
to the second support member.
Other exemplary embodiments comprise a method of manufacturing a
support member, the method comprising: providing a sheet of first material,
wherein the first material is air impermeable; creating an aperture in the
sheet;
covering a portion of the aperture with a second material, wherein the second
material is air permeable and liquid impermeable; welding the second material
to the first material; and configuring the sheet to form an inflatable
enclosure.
In exemplary embodiments, the second material is high frequency welded to
the first material.
Brief Description of the Figures
While exemplary embodiments of the present invention have been
shown and described in detail below, it will be clear to the person skilled in
the
art that changes and modifications may be made without departing from the
scope of the invention. As such, that which is set forth in the following
description and accompanying figures is offered by way of illustration only
and
not as a limitation. The actual scope of the invention is intended to be
defined
by the following claims, along with the full range of equivalents to which
such
claims are entitled.
In addition, one of ordinary skill in the art will appreciate upon reading
and understanding this disclosure that other variations for the invention
described herein can be included within the scope of the present invention.
For example, exemplary embodiments are disclosed with a single sheet
configured to form an inflatable enclosure. In other exemplary embodiments,
the inflatable enclosure may comprise multiple panels coupled to form an
inflatable enclosure. For example, exemplary embodiments may comprise an
inflatable enclosure with separate top, bottom, side and end panels.
In the following Detailed Description of Disclosed Embodiments,
various features are grouped together in several embodiments for the purpose
of streamlining the disclosure. This method of disclosure is not to be
interpreted as reflecting an intention that exemplary embodiments of the
invention require more features than are expressly recited in each claim.
Rather, as the following claims reflect, inventive subject matter lies in less
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than all features of a single disclosed embodiment. Thus, the following claims
are hereby incorporated into the Detailed Description of Disclosed
Embodiments, with each claim standing on its own as a separate
embodiment.
The following Figures are referenced herein. The Figures illustrating
the exemplary embodiments are not to scale.
Figure 1 provides a top view of one exemplary embodiment of a
support system component according to the present disclosure.
Figure 2 provides a side view of one exemplary embodiment of a
support member according to the present disclosure.
Figure 3 provides a cross-section view of one exemplary embodiment
of a support member according to the present disclosure.
Figure 4 provides an end view of one exemplary embodiment of a
support member according to the present disclosure.
Figure 5 provides a top view of one exemplary embodiment of a
support system component according to the present disclosure.
Figure 6 provides a side view of one exemplary embodiment of a
support member according to the present disclosure.
Figure 7 provides a cross-section view of one exemplary embodiment
of a support member according to the present disclosure.
Figure 8 provides an end view of one exemplary embodiment of a
support member according to the present disclosure.
Figure 9 provides a top view of a one exemplary embodiment of a
support system according to the present disclosure.
Figure 10 provides a side view of a one exemplary embodiment of a
support system according to the present disclosure.
Detailed Description of Exemplary Embodiments
Exemplary embodiments of the present disclosure are directed to an
apparatus that functions as a patient support surface or therapeutic surface
formed from multiple materials that exhibit various properties and are joined
at
various locations using a welding technique to produce a biologically sealed
and controlled air loss surface. In certain exemplary embodiments, the
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welding technique used to couple or join the materials is a high frequency
(HF) welding technique. The materials may comprise varying properties,
including liquid, vapor, and air permeability, as well as friction
coefficients.
For example, in exemplary embodiments of the present disclosure, HF
welding, also referred to as dielectric welding or radio frequency (RF)
welding
can be used to join a urethane based material to a polytetrafluoroethylene
(PTFE or Teflon) -based material such as GORE-TEX , to form a support
cushion having low-air-loss features, antimicrobial features, structurally
sound
features, and controlled air loss features, among others.
High frequency welding is a process that uses high frequency radio
energy to produce molecular agitation, and therefore heat, in various types of
materials so as to fuse the materials together. Thus, in various embodiments,
materials used to form support surfaces and therapeutic surfaces of the
present disclosure that are capable of being HF welded are contemplated and
are not limited to urethane based materials and Teflon based materials such
as GORE-TEX .
Exemplary embodiments of the process involve subjecting the
materials to be fused or joined to a high frequency (between -13 and
-100MHz) electromagnetic field, which is normally applied between two metal
surfaces (e.g., metal bars). These surfaces also function as pressure
applicators during heating and cooling. The electromagnetic field causes the
molecules in polar thermoplastics to oscillate and thus, depending on their
geometry and dipole moment, these molecules may translate some of this
oscillatory motion into thermal energy and cause heating of the material and
eventually, the joining or fusing of the material.
HF welding is useful for joining polymers that have strong dipoles, such
as polyvinyl chloride (PVC), polyurethanes, and polyamides, among others. It
is possible to RF weld other polymers including nylon, Polyethylene
Terephthalate (PET), Ethylene Vinyl Acetate (EVA) and some Acrylonitrile
Butadiene Styrene (ABS) resins, among others.
In various exemplary embodiments, other forms of welding are also
contemplated. Hot gas welding, hot plate welding, ultrasonic welding,
vibration
or friction welding, laser welding, and solvent welding, among others may be
implemented. As one of ordinary skill in the art will appreciate, some of
these
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forms of welding might be more conducive to welding various plastics and
other materials than other forms of welding and thus, the types of materials
to
be welded to form a patient support surface and/or therapeutic surface of the
present disclosure can be chosen based upon the form of welding desired or
vice versa.
The Figures herein follow a numbering convention in which the first
digit or digits correspond to the drawing Figure number and the remaining
digits identify an element or component in the drawing. Similar elements or
components between different Figures may be identified by the use of similar
digits. For example, an element in Figure 1 may be referenced as 110, and a
similar element may be referenced as 210 in Figure 2. As will be appreciated,
elements shown in the various exemplary embodiments herein can be added,
exchanged, and/or eliminated so as to provide any number of additional
embodiments of the support members and support systems of the present
disclosure.
Referring now to Figure 1, a sheet 102 comprises an aperture 106. In
the exemplary embodiment shown in Figure 1, sheet 102 comprises a first
end 151, a second end 152, a first side 153, and a second side 154. In
exemplary embodiments, sheet 102 is comprised of a substantially air
impermeable material. In a particular exemplary embodiment, sheet 102 is
comprised of a material that is also substantially vapor and liquid
impermeable, such as urethane-backed nylon. As shown in Figure 1, a
material 104 covers aperture 106 (or a portion thereof). In exemplary
embodiments, material 104 is substantially air permeable. In
certain
exemplary embodiments, material 104 may be a substantially vapor
permeable and liquid impermeable material comprising PTFE, such as
Go reTex0.
In the exemplary embodiment shown in Figure 1, material 104 is
welded to sheet 102 around the perimeter of aperture 106. In particular
= 30 exemplary embodiments, material 104 is welded to sheet 102 via a high
frequency welding process. In the exemplary embodiment shown, sheet 102
comprises an opening 110 which maybe connected to a source (not shown)
of pressurized air or other fluid.
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In exemplary embodiments, material 104 may be sized so that it is
slightly larger than aperture 106 and overlaps sheet 102 at the perimeter of
aperture 106. In such exemplary embodiments, material 104 may be lap
welded to sheet 102. In other exemplary embodiments, material 104 may be
sized so that it is substantially the same size as aperture 106. In such
exemplary embodiments, a ring of backing material (not shown) may be
placed at the junction of material 104 and sheet 102 to allow a butt-weld to
be
formed between material 104 and sheet 102. In
certain exemplary
embodiments, the backing material may be comprised of the same material
as sheet 102.
In the exemplary embodiment shown in Figure 1, aperture 106 is
approximately centered between first side 153 and second side 154. In the
exemplary embodiment shown in Figure 1, aperture 106 also extends along a
majority of the length of sheet 102.
Referring now to Figures 2 and 3, sheet 102 can be configured to form
a support member 100 that can be inflated with air or another pressurized
fluid. In the exemplary embodiment shown in Figures 2 and 3, sheet 102 has
been arranged so that first side 153 is coupled to second side 154. In
addition, first end 151 and second end 152 have been sealed so that sheet
102 forms an elongated enclosure. In exemplary embodiments, first side 153
is coupled to second side 154 via welding to form a flat seam weld 114 and
first end 151 and second end 152 are sealed via welding to form a pair of flat
seam welds 112. In certain exemplary embodiments, first side 153 is high
frequency welded to second side 154 and first end 151 and second end 152
are sealed via high frequency welding. In exemplary embodiments, opening
110 can be connected, for example, to an air pump (not shown) to move air
into the support member 100 to both inflate the support member 100 and to
maintain a partial pressure difference of vapor and thus, aid in moisture and
heat removal from the patient and from the environment surrounding the
patient.
Figure 3 illustrates a cross-section of Figure 2 taken at section line 3-3.
As shown in the exemplary embodiment of Figure 3, support member 100
may incorporate a baffle 116 that extends across support member 100. In
this exemplary embodiment, each end of baffle 116 is coupled to sheet 102 so
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the cross-section of support member 100 is narrower than it is high. In the
exemplary embodiment shown in Figure 3, baffle 116 is sized so that the
cross-section of support member generally forms an hourglass or "figure-8"
shape with an indentation 117 at each side of support member 100. The
incorporation of baffle 116 provides a narrower cross-section for support
member 100 and allows for a greater number of support members 100 to be
incorporated into a patient support system.
Figure 4 illustrates an end view of an exemplary embodiment of a
support member 101 that does not incorporate a baffle. As shown, the cross-
section of support member 100 in Figure 4 is a generally circular shape.
Other features are generally equivalent to those disclosed in the discussion
of
Figure 3.
Referring now to Figures 5-8, an exemplary embodiment of a support
member 200 comprises a lower portion 205 with a cap or upper portion 210.
Exemplary embodiments of support member 200 are similar to those of
support member 100. However, exemplary embodiments of support member
200 comprise a material 204 that is substantially air impermeable, rather than
the air permeable material 104 used in support member 100. In exemplary
embodiments, material 204 is also vapor permeable and liquid impermeable.
In addition, exemplary embodiments of support member 200 comprise an
aperture 206 that is larger than aperture 106 of support member 100. In
exemplary embodiments, aperture 204 extends substantially across the entire
length of support member 200 so that it is proximal to first end 251 and
second end 252.
Similar to the construction techniques used to form support member
100, exemplary embodiments of support member 200 may be formed by
welding a first side 253 to a second side 254 and sealing first and second
ends 251 and 252. Material 204 may also be welded to sheet 202 to cover
aperture 206 in exemplary embodiments.
In other embodiments, support member 200 may be constructed in
other manners. For example, support member 200 may comprise separate
pieces of material, rather than a single sheet 202 with an aperture 206.
In the exemplary embodiment shown in Figure 7, sheet 202 has been
formed into a support member with an hourglass or "figure-8" cross-section.
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In this exemplary embodiment, support member 202 incorporates a baffle
216. As shown in the exemplary embodiment of Figure 8, sheet 202 may also
be formed into a support member 201 that is generally cylindrical with a
circular cross section in certain exemplary embodiments.
Referring now to Figures 9 and 10, an exemplary embodiment of a
support system 300 comprises a first set of support members 100 and a
second set of support members 200. As shown in the top view of Figure 9,
support members 100 and 200 are arranged in a generally alternating
configuration so that a support member 100 is located between two support
members 200. Support members 100 and 200 may be inflated with
pressurized air or another source of fluid.
As shown in the partial side view of the exemplary embodiment in
Figure 10, support members 200 are taller than support members 100. In
exemplary embodiments, support members 200 are comprised of material
202 that is substantially air impermeable with a cap of material 204 that is
air
impermeable and vapor permeable. In exemplary embodiments, support
members 100 comprise a material 102 that is air impermeable and a cap of
material 104 that is air permeable and liquid impermeable. In exemplary
embodiments, support members 200 will provide primary support for a person
(not shown) laying on support member 300. In exemplary embodiments, air
can flow through support members 100 and exit material 104 covering
aperture 106. Such air flow can assist in transferring moisture vapor from a
person's body as they lay on support system 300. Air flow may also assist in
removing moisture vapor from support members 100.
In exemplary embodiments, moisture vapor may transfer from a person
through material 204 and into support member 200. In the exemplary
embodiment shown in Figure 9, material 204 extends nearly to edges 305 and
310 of support system 300. Therefore, a significant portion of material 204
will not be in contact with a person laying on support system 300. As a
result,
moisture vapor can also exit support member 200 via material 204. In
exemplary embodiments, increasing the area covered by material 204 will
increase the rate at which moisture vapor can be transferred from a person
being supported by support system 300.
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In the exemplary embodiment shown in Figures 9 and 10, support
system 300 is configured to reduce the amount of air flow needed to support a
person and provide moisture vapor transfer capabilities. Primary support is
provided by support members 200, which comprise material that is
substantially air impermeable, and therefore requires minimal air flow to
remain inflated and provide support. Support members 100 comprise material
104 which is air permeable and therefore requires more airflow than support
members 200 to stay inflated. The amount of air (or other pressurized fluid)
required to inflate support members 100 and 200 can be reduced because the
air flow is restricted to areas covered by material 104. In addition, the
power
requirements and noise levels of equipment needed to inflate support
members 100 and 200 are also reduced. In certain exemplary embodiments,
support members 100 may be coupled to one source of pressurized fluid and
support members 200 may be coupled to a second source of pressurized
fluid. In such exemplary embodiments, each source of pressurized fluid can
be configured to the operating parameters required. For example, the source
of pressurized fluid for support members 100 may be a lower pressure, higher
volume source than the source of pressured fluid for support members 200.
In exemplary embodiments, support members 100 and 200 can be
welded together to form the contiguous patient support surface system 300.
In other embodiments, the support members 100 and 200 can be enclosed by
a cover (not shown) to form the contiguous patient support surface 300.
While exemplary embodiments have been shown and described in
detail above, it will be clear to the person skilled in the art that changes
and
modifications may be made without departing from the scope of the invention.
As such, that which is set forth in the foregoing description and accompanying
drawings is offered by way of illustration only and not as a limitation. The
actual scope of the invention is intended to be defined by the following
claims,
along with the full range of equivalents to which such claims are entitled.
In addition, one of ordinary skill in the art will appreciate upon reading
and understanding this disclosure that other variations for the invention
described herein can be included within the scope of the present invention.
For example, the patient support surface can be coated with an antimicrobial
agent, as are known or will be known.
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In the foregoing Detailed Description, various features are grouped
together in several embodiments for the purpose of streamlining the
disclosure. This method of disclosure is not to be interpreted as reflecting
an
intention that the embodiments of the invention require more features than are
expressly recited in each claim. Rather, as the following claims reflect,
inventive subject matter lies in less than all features of a single disclosed
embodiment. Thus, the following claims are hereby incorporated into the
Detailed Description, with each claims standing on its own as a separate
embodiment.
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