U.S. patent application number 13/241693 was filed with the patent office on 2013-03-28 for moisture management and transport cover.
The applicant listed for this patent is Charles A. Lachenbruch, Christopher R. O'Keefe, Timothy J. Receveur, Rachel Williamson. Invention is credited to Charles A. Lachenbruch, Christopher R. O'Keefe, Timothy J. Receveur, Rachel Williamson.
Application Number | 20130074272 13/241693 |
Document ID | / |
Family ID | 47257397 |
Filed Date | 2013-03-28 |
United States Patent
Application |
20130074272 |
Kind Code |
A1 |
Lachenbruch; Charles A. ; et
al. |
March 28, 2013 |
Moisture Management and Transport Cover
Abstract
An occupant support (20) includes an intermediate layer (26, 30,
120) and a wicking layer (52) atop the intermediate layer. The
wicking layer comprises a first region (62) having a lower moisture
wick rate (W1) and a second region (64) having a higher wick rate
(W2). A moisture management cover (52) for use with an occupant
support article has discrete higher (64) and lower (62) wick rate
regions. A related method for transporting moisture away from a
target region of an occupant support comprises distributing the
moisture over an area beyond area A and exposing the distributed
moisture to a fluid stream capable of receiving the moisture.
Inventors: |
Lachenbruch; Charles A.;
(Lakeway, TX) ; O'Keefe; Christopher R.;
(Batesville, IN) ; Receveur; Timothy J.;
(Guilford, IN) ; Williamson; Rachel; (Batesville,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lachenbruch; Charles A.
O'Keefe; Christopher R.
Receveur; Timothy J.
Williamson; Rachel |
Lakeway
Batesville
Guilford
Batesville |
TX
IN
IN
IN |
US
US
US
US |
|
|
Family ID: |
47257397 |
Appl. No.: |
13/241693 |
Filed: |
September 23, 2011 |
Current U.S.
Class: |
5/691 |
Current CPC
Class: |
A61G 7/05784 20161101;
A61G 7/05792 20161101; A61G 7/05769 20130101 |
Class at
Publication: |
5/691 |
International
Class: |
A47C 17/00 20060101
A47C017/00; A47G 9/02 20060101 A47G009/02 |
Claims
1. An occupant support comprising: a intermediate layer defining at
least part of a fluid flowpath and having a vapor permeable
occupant side; and a wicking layer atop the intermediate layer, the
wicking layer comprising a first region having a first moisture
wick rate and a second region having a second moisture wick rate
that exceeds the first moisture wick rate.
2. The occupant support of claim 1 wherein the first region is a
perimetric region that bounds the second region.
3. The occupant support of claim 1 wherein the wicking layer is in
the form of a fitted sheet.
4. The occupant support of claim 1 wherein the second wick rate
comprises longitudinal and lateral wick rates at least the lateral
one of which is greater than the first wick rate and the lateral
wick rate exceeds the longitudinal wick rate.
5. The occupant support of claim 1 wherein the second region is
nonrectangular.
6. The occupant support of claim 1 wherein the wicking layer is
removably attached to the intermediate layer.
7. The occupant support of claim 1 wherein the wicking layer is
nonremovably attached to the intermediate layer.
8. The occupant support of claim 1 wherein the wicking layer
comprises a material bonded to the intermediate layer by a vapor
permeable adhesive.
9. The occupant support of claim 1 wherein the wicking layer is a
vapor permeable coating.
10. The occupant support of claim 1 wherein the wicking layer is
integrated into the intermediate layer.
11. The occupant support of claim 1 wherein the wick rate of the
second region is nonuniform.
12. The occupant support of claim 1 wherein the intermediate layer
is a microclimate control topper.
13. A moisture management cover, the cover being cooperable with an
occupant support article having an occupant support side so that
the occupant support side and an opposing portion of the cover
define a fluid flowpath, the cover having discrete higher and lower
wick rate regions, the higher wick rate region having a higher
moisture wick rate than that of the lower wick rate region.
14. The moisture management cover of claim 13 wherein the higher
wick rate region is a perimetral region that bounds the lower wick
rate region.
15. The moisture management cover of claim 13 wherein the cover is
in the form of a fitted sheet.
16. The moisture management cover of claim 13 wherein the higher
wick rate comprises longitudinal and lateral wick rates at least
the lateral one of which is greater than the lower wick rate and
the lateral wick rate exceeds the longitudinal wick rate.
17. The moisture management cover of claim 13 wherein the higher
wick rate region is nonrectangular.
18. The moisture management cover of claim 13 wherein the wicking
layer is removably attachable to a intermediate layer.
19. The moisture management cover of claim 13 wherein the higher
wick rate region comprises a material bonded to the intermediate
layer by a vapor permeable adhesive.
20. The moisture management cover of claim 13 wherein the wicking
layer is a vapor permeable coating.
21. The moisture management cover of claim 13 wherein the wick rate
of the higher wick rate region is nonuniform.
22. A method for transporting moisture away from a target region of
an occupant support, the region having an area A, the method
comprising: distributing the moisture over an area beyond area A;
and exposing the larger area to a fluid stream capable of receiving
the moisture
23. The method of claim 22 wherein the area beyond area A is
laterally beyond area A.
Description
TECHNICAL FIELD
[0001] The subject matter described herein relates to a cover for
enhanced in-plane moisture transport. One example application for
the cover is on a hospital bed where it may be used in conjunction
with a microclimate control topper or as a stand alone mattress
cover to help transport moisture away from a region underneath an
occupant of the bed thus achieving better control of moisture on
the occupant's skin.
BACKGROUND
[0002] Long term occupants of beds, such as patients confined to a
hospital bed, are at risk of skin breakdown. Such risks are
exacerbated by excessive moisture on the occupant's skin.
Frequently the source of the moisture is the occupant's own
perspiration. One known way to control moisture in contact with the
occupant's skin is to place a microclimate control (MCC) topper
between the mattress and the occupant. A typical MCC topper
comprises a vapor permeable top side and a bottom side. The sides
define an interior cavity having an air inlet and an air outlet.
The interior cavity serves as a flowpath for ambient or conditioned
air. In operation, a blower propels a stream of air through the
flowpath. Occupant perspiration, specifically the gaseous phase of
the perspiration, enters the flowpath through the vapor permeable
top side. The ambient or conditioned air flowing through the
flowpath carries the moisture away. The flowpath thus serves as a
moisture sink for moisture in contact with the occupant's skin.
[0003] Although MCC toppers are effective, their effectiveness is
limited by the fact that the source moisture is mostly present in a
confined area immediately underneath the occupant. Only those
portions of the air stream directly under the moist area are
effective at removing the moisture. As a result some of the
moisture removal capacity of the topper is unused.
SUMMARY
[0004] One embodiment of an occupant support includes an
intermediate layer defining at least part of a fluid flowpath and
having a vapor permeable occupant side. The occupant support also
includes a wicking layer atop the intermediate layer. The wicking
layer comprises a first region having a first moisture wick rate
and a second region having a second moisture wick rate that exceeds
the first moisture wick rate. A moisture management cover described
herein is cooperable with an occupant support article having an
occupant support side so that the occupant support side and an
opposing portion of the cover define a fluid flowpath. The cover
has discrete higher and lower wick rate regions. A related method
for transporting moisture away from a target region of area A of an
occupant support comprises distributing the moisture over an area
beyond area A and exposing the distributed moisture to a fluid
stream capable of receiving the moisture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The foregoing and other features of the various embodiments
of the moisture transport cover described herein will become more
apparent from the following detailed description and the
accompanying drawings in which:
[0006] FIG. 1 is a simplified side elevation view of a hospital bed
showing a bed frame, a mattress, an intermediate layer in the form
of a microclimate control (MCC) topper, and a moisture transport
cover, which is also referred to as a wicking layer, in the form of
a substantially flat sheet removably secured to the topper by a
zipper.
[0007] FIG. 2 is a plan view of the bed of FIG. 1 showing that the
wicking layer has a higher wick rate central region and a lower
wick rate perimetrical region.
[0008] FIG. 3 is a simplified perspective view of the bed of FIGS.
1-2.
[0009] FIG. 4 is a perspective view of a wicking layer in the form
of a fitted sheet.
[0010] FIG. 5 is a view showing the wicking layer nonremovably
secured to a topper.
[0011] FIG. 6 is a view in which the wicking layer comprises a
wicking material bonded to the topper by a vapor permeable
adhesive.
[0012] FIG. 7 is a view in which the wicking layer is a vapor
permeable coating applied to a topper.
[0013] FIG. 8 is a view in which the wicking layer is integrated
into the topper.
[0014] FIG. 9 is a perspective view showing an embodiment in which
an air mattress comprising multiple bladders plays the role of the
intermediate layer.
[0015] FIGS. 10-11 are perspective views each showing moisture
management covers in isolation, i.e. not in the context of a
bed.
DETAILED DESCRIPTION
[0016] Referring to FIGS. 1-3, an occupant support such as a
hospital bed 20 extends longitudinally from a head end H to a foot
end F and laterally from a right side R (seen in the plane of FIG.
1) to a left side L. The bed includes a frame 22, a mattress 24
supported on the frame, and an intermediate layer 26 in the form of
a microclimate control topper 30 resting on the mattress. The
topper is referred to as an intermediate layer 26 because of its
position between frame 22 and occupant 32.
[0017] The microclimate control topper 30 has a vapor permeable top
or occupant side 36, whose longitudinal and lateral dimensions are
D1, D2, a bottom side 38, and an air permeable spacer 40 between
the sides. The occupant and bottom sides 36, 38 define a fluid
flowpath 42 extending longitudinally substantially the length L of
the topper. The topper has an inlet 46 and an outlet 48. A blower,
not shown, propels a stream of air 50 through the flowpath. In
operation, the occupant's perspiration, after having transitioned
to the gaseous phase, passes through the vapor permeable occupant
side 36 and enters the air stream 50. The air stream carries the
moisture away through outlet 48. In the embodiment of FIGS. 1-3
topper sides 36, 38 of the topper or intermediate layer define the
flowpath from inlet 46 to outlet 48. In another embodiment
described below, the intermediate layer only partly defines the
flowpath.
[0018] The occupant support also includes a moisture management
cover or wicking layer 52, atop the intermediate layer. At least
part of the wicking layer is made of a material exhibiting a high
in-plane moisture transport rate, referred to herein as a wick
rate. Examples of materials having high wick rates include
polypropylene, Meryl Skinlife.RTM., SORBTEK.TM., and Poro-Tex
expanded PTFE (ePTFE). The wicking layer of FIGS. 1-3 is in the
form of a substantially flat sheet having longitudinal and lateral
dimensions D3, D4 approximately equal to the longitudinal and
lateral dimensions D1, D2 respectively of occupant side 36 of the
topper. Although the wicking layer can be a stand-alone moisture
management cover, the illustrated wicking layer is attached to the
intermediate layer, i.e. to topper 30, by a zipper 58, a strip of
VELCRO.RTM. or other connection that allows the wicking layer to be
separated or removed from the topper without causing damage to or
destruction of the wicking layer, the topper or the connection
therebetween.
[0019] The illustrated wicking layer comprises a first region 62
having a first moisture wick rate W1 and a second region 64 having
a second moisture wick rate W2 that exceeds the first moisture wick
rate. In one embodiment the longitudinal borders of region 64 are
laterally extending border 91 located approximately at the
occupant's scapula and border 92 located at about mid-thigh. In
another embodiment the borders are border 93 at about midway along
the occupant's back and 94 at about the occupant's buttocks. First
region 62 is a perimetrical region that laterally and
longitudinally bounds second region 64. The second region extends
laterally beyond the approximate outline 66 of a supine occupant of
the bed. The high wick rate of second region 64 spatially
distributes the occupant's perspiration more readily than would be
the case if the wick rate were lower. In particular the high wick
rate of region 64 spreads the perspiration beyond the outline 66 of
the occupant. More moisture is therefore exposed to air stream 50
resulting in better use of the moisture removal capacity of the
topper and an attendant increase in moisture removal from the
occupant's skin. Nevertheless, it is also contemplated that a high
wick rate that does not extend laterally beyond the occupant could
be beneficial.
[0020] The wicking layer illustrated in FIGS. 1-3 is in the form of
a flat sheet whose dimensions D3, D4 are only slightly larger than
topper dimensions D1, D2 so that zipper 58 will not interfere with
occupant comfort. The sheet could be made larger so that a
considerably larger portion of it drapes over the edge of the
topper, or smaller so that it does not completely cover occupant
side 36 of the topper. Moreover, forms other than flat are not
precluded. For example FIG. 4 shows the wicking layer in the form
of a fitted sheet having elastic corners 70 and/or an elastic edge
72 so that the wicking layer fits snugly on topper 30.
[0021] Wick rate W2 may be spatially nonuniform, i.e. the wick rate
need not be constant in any given direction. In addition the wick
rate, even if constant in any given direction, need not be the same
in one given direction as in another given direction. For example
it is envisioned that wick rate W2 could have a value W2.sub.LONG
in the longitudinal direction and a different, higher value
W2.sub.LAT in the lateral direction, with at least W2.sub.LAT being
greater than first wick rate W1. Because most occupants are taller
than they are wide, the higher wick rate in the lateral direction
can quickly transport moisture beyond the left and right edges 74,
76 of the occupant outline 66 where that moisture will be exposed
to the drying effects of ambient air in addition to being acted on
by the internal air stream 50. The higher lateral wicking rate is
therefore believed to be more efficacious than a higher
longitudinal wicking rate.
[0022] In FIGS. 1-4 second region 64 is rectangular which, as used
herein, includes the special case of a square, and the wicking
layer is removably attached to the intermediate layer (topper 30).
FIG. 6A shows a nonrectangular second region 64, specifically a
substantially circular region. The illustrated nonrectangular
region could also be shaped and dimensioned so that distance D from
the edge of occupant outline 66 to the edge of second region 64
were approximately constant, or varied depending on typical
perspiration rates at different portions of the occupant's body.
FIGS. 5-8 show alternative architectures. In FIGS. 5A-5B the
alternative architecture is one in which wicking layer 52 is
nonremovably attached to the topper, for example by a stitched seam
80. In such an arrangement at least the stitching would be
destroyed or damaged by the act of separating the wicking layer
from the topper. In FIGS. 6A-6B the alternative architecture is one
in which the wicking layer 52 comprises higher and lower wick rate
materials 84, 86 bonded to intermediate layer 30 by a vapor
permeable adhesive 88. Alternatively the bond could be effected by
spot bonding with a non-vapor permeable adhesive. Higher wick rate
region 64 corresponds to the higher wick rate material 84; lower
wick rate region 62 corresponds to the lower wick rate material 86.
In FIGS. 7A-7B, the alternative architecture is one in which
wicking layer 52 is a vapor permeable higher wick rate coating 100
and a vapor permeable lower wick rate coating 102 applied to the
topper. Higher wick rate region 64 corresponds to the higher wick
rate coating 100; lower wick rate region 62 corresponds to the
lower wick rate coating 102. In FIGS. 8A-8B the alternative
architecture is one in which wicking layer 52 comprises higher and
lower wick rate overlays 106, 108 integrated into the topper.
Higher wick rate region 64 corresponds to the higher wick rate
overlay 106; lower wick rate region 62 corresponds to the lower
wick rate overlay 108.
[0023] In the variants of FIGS. 6-8, the lower wick rate material
86 (FIG. 6), lower wick rate coating 102 (FIG. 7) and lower wick
rate overlay 108 (FIG. 8) could be dispensed with, in which case
the portion of occupant side 36 of topper 30 outboard of region 64
could serve as the low wick rate region having a wick rate W1.
[0024] FIG. 9 shows an embodiment in which an air mattress 120
comprising multiple bladders 122 plays the role of intermediate
layer 26. Collectively, the bladders define a mattress occupant
side 136 and a bottom side 138. Air discharge apertures 126
penetrate through the occupant side of the mattress. A blower, not
shown, supplies pressurized air to inflate the bladders. The
moisture management cover or wicking layer 52 rests atop the air
mattress. In this embodiment, intermediate layer 26, as represented
by air mattress 120, only partly defines fluid flowpath 42 for
airstream 50, and is analogous to the bottom side 38 of the topper
in the embodiments of FIGS. 1-3. The wicking layer itself
cooperates with the occupant side of the mattress to define
flowpath 42 and is therefore analogous to the occupant side 36 of
the topper in the embodiments of FIGS. 1-3. Collectively, apertures
126 serve as an inlet analogous to inlet 26 of FIGS. 1-3. Air
discharges from the flowpath at the edges of the wicking layer. In
operation the high wick rate wicking layer causes moisture to
spread out over a relatively large area so that it can be more
readily carried away by airstream 50. If the wicking layer is
connected to the intermediate layer by an airtight seam, other
avenues for air discharge can be provided.
[0025] FIGS. 10-11 shows the wicking layer or moisture management
cover 52 in isolation, i.e. without the contextual framework of a
hospital bed. The cover is nevertheless capable of being placed
atop a companion article such as air mattress 120 of FIG. 9 or
mattress 24 augmented by MCC topper 30 of FIGS. 1-3. The moisture
management cover has discrete higher and lower wick rate regions
64, 62 with wick rates of W2 and W1 respectively where W2 is
greater than W1 (FIG. 11). The moisture management cover can take
the form of, for example, a flat sheet (as depicted in FIG. 10) or
a fitted sheet (as depicted in FIG. 11). The illustrated cover of
FIG. 10 includes an attachment element or elements, such as zipper
58 so that the moisture management cover can be removably joined to
the occupant support article by way of a cooperating attachment
element on the occupant support article. Alternatively the moisture
management cover could be nonremovably secured to the occupant
support article by, for example, continuous or spot stitching. In
yet another alternative the cover is devoid of a closure element
and is merely placed atop the occupant support article without
being secured thereto. As already described previously the high and
low wick rate regions of FIGS. 10-11 can be bonded onto a
substrate, can be a coating applied to a substrate or can be
integral with the cover. The wick rate can be spatially
nonuniform.
[0026] Although the embodiments disclosed herein have a first
region with a lower wick rate and a second region with a higher
wick rate, more than two regions each having individual, customized
wick rates can be used.
[0027] The terms "wicking" and its variants, as used herein to
describe the moisture management cover, are intended to convey the
notion of moisture transport in the plane of the cover and are not
to be interpreted as limited to any particular physical mechanism
of moisture transport.
[0028] Although this disclosure refers to specific embodiments, it
will be understood by those skilled in the art that various changes
in form and detail may be made without departing from the subject
matter set forth in the accompanying claims.
* * * * *