[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.
[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.
[0004] US Patent Application Publication No. 2007/0261548 discloses a MCC topper in which the vapor permeable top side has a first region with
a first permeability and a second region having a second permeability, wherein the
second permeability is greater than the first permeability so that vapor transfers
through the vapor permeable top side at a higher rate in the second region.
[0005] The invention is defined by the claims.
[0006] The invention will now be further described by way of example with reference to the
accompanying drawings, in which:
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.
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.
FIG. 3 is a simplified perspective view of the bed of FIGS. 1-2.
FIG. 4 is a perspective view of a wicking layer in the form of a fitted sheet.
FIG. 5 is a view showing the wicking layer nonremovably secured to a topper.
FIG. 6 is a view in which the wicking layer comprises a wicking material bonded to the topper
by a vapor permeable adhesive.
FIG. 7 is a view in which the wicking layer is a vapor permeable coating applied to a topper.
FIG. 8 is a view in which the wicking layer is integrated into the topper.
FIG. 9 is a perspective view showing an embodiment in which an air mattress comprising multiple
bladders plays the role of the intermediate layer.
FIGS. 10-11 are perspective views each showing moisture management covers in isolation, i.e.
not in the context of a bed.
[0007] 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.
[0008] 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.
[0009] 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
®, SORBTEK™, 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 form part of 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
® 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.
[0010] 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.
[0011] 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.
[0012] 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. The wick rate
W2 has a value
W2LONG in the longitudinal direction and a different, higher value
W2LAT in the lateral direction, with at least
W2LAT 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.
[0013] 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. In one embodiment (not shown), the overlays
106,
108 form the top wall of the topper
52.
[0014] 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.
[0015] 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.
[0016] FIGS.
10-11 shows 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.
[0017] 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.
[0018] 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.
[0019] The terms "moisture management cover" and "wicking layer" are used somewhat interchangeably
herein but as will be appreciated, at least one embodiment is disclosed where a moisture
management cover includes a wicking layer and where there is a wicking layer but not
a stand alone moisture management cover.
[0020] 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.
1. An occupant support comprising an intermediate layer (26, 30) defining at least part
of a fluid flowpath (42) and having a vapor permeable occupant side (36), and a wicking
layer (52) atop the intermediate layer, the wicking layer comprising a first region
(62) having a first moisture wick rate and a second region (64) having a second moisture
wick rate that exceeds the first moisture wick rate, characterized in that 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.
2. The occupant support of claim 1 wherein the wicking layer (52) is integrated into
the intermediate layer (26, 30).
3. The occupant support of either claim 1 or claim 2 wherein the intermediate layer is
a microclimate control topper.
4. The occupant support of either claim 1 or claim 3, wherein the wicking layer (52)
is removably attached to the intermediate layer (26, 30).
5. The occupant support of either claim 1 or claim 3, wherein the wicking layer (52)
is nonremovably attached to the intermediate layer (26, 30).
6. The occupant support of either claim 1 or claim 3, wherein the wicking layer comprises
a material (84, 86) bonded to the intermediate layer (30) by a vapor permeable adhesive
(88).
7. The occupant support of either claim 1 or claim 3, wherein the wicking layer is a
vapor permeable coating (100, 102).
8. The occupant support of either claim 1 or claim 3, wherein the wicking layer is in
the form of a fitted sheet (52).
9. The occupant support of any one of claims 1 to 8, wherein the first region (62) is
a perimetric region that bounds the second region (64).
10. The occupant support of any one of claims 1 to 9, wherein the second region (64) is
nonrectangular.
11. The occupant support of any one of claims 1 to 10, wherein the wick rate of the second
region (64) is nonuniform.
1. Benutzerunterstützungsvorrichtung mit einer Zwischenschicht (26, 30), die mindestens
Teil eines Fluiddurchflussweges (42) ist und eine dunstdurchlässige Benutzerseite
(36) aufweist, und mit einer auf der Zwischenschicht befindlichen Drainageschicht
(52), wobei die Drainageschicht eine erste Zone (62) mit einer ersten Feuchtigkeitsdrainageleistung
und eine zweite Zone (64) mit einer zweiten Feuchtigkeitsdrainageleistung umfasst,
die höher als die erste Feuchtigkeitsdrainageleistung ist, dadurch gekennzeichnet, dass zur zweiten Drainageleistung in Längsrichtung und seitlich wirkende Drainageleistungen
gehören, von denen zumindest die seitlich wirkende Leistung über der ersten Drainageleistung
liegt und die seitlich wirkende Drainageleistung über die in Längsrichtung erbrachte
Drainageleistung hinausgeht.
2. Benutzerunterstützungsvorrichtung nach Anspruch 1, wobei die Drainageschicht (52)
in die Zwischenschicht (26, 30) integriert ist.
3. Benutzerunterstützungsvorrichtung nach entweder Anspruch 1 oder Anspruch 2, wobei
es sich bei der Zwischenschicht um eine Auflage zur Mikroklimaregulierung handelt.
4. Benutzerunterstützungsvorrichtung nach entweder Anspruch 1 oder Anspruch 3, wobei
die Drainageschicht (52) mit der Zwischenschicht (26, 30) lösbar verbunden ist.
5. Benutzerunterstützungsvorrichtung nach entweder Anspruch 1 oder Anspruch 3, wobei
die Drainageschicht (52) unlösbar mit der Zwischenschicht (26, 30) verbunden ist.
6. Benutzerunterstützungsvorrichtung nach entweder Anspruch 1 oder Anspruch 3, wobei
die Drainageschicht ein Material (84, 86) umfasst, das mit der Zwischenschicht (30)
durch einen dunstdurchlässigen Kleber (88) verklebt ist.
7. Benutzerunterstützungsvorrichtung nach entweder Anspruch 1 oder Anspruch 3, wobei
die Drainageschicht eine dunstdurchlässige Beschichtung (100, 102) ist.
8. Benutzerunterstützungsvorrichtung nach entweder Anspruch 1 oder Anspruch 3, wobei
die Drainageschicht in Form einer Folienauflage (52) ausgebildet ist.
9. Benutzerunterstützungsvorrichtung nach irgendeinem der Ansprüche 1 bis 8, wobei die
erste Zone (62) eine perimetrische Zone ist, die an die zweite Zone (64) angrenzt.
10. Benutzerunterstützungsvorrichtung nach irgendeinem der Ansprüche 1 bis 9, wobei die
zweite Zone (64) von nicht rechteckiger Form ist.
11. Benutzerunterstützungsvorrichtung nach irgendeinem der Ansprüche 1 bis 10, wobei die
Drainageleistung der zweiten Zone (64) ungleichförmig ist.
1. Support d'occupant comprenant une couche intermédiaire (26, 30) définissant au moins
une partie d'une trajectoire d'écoulement de fluide (42) et ayant un côté d'occupant
perméable à la vapeur (36), et une couche à effet de mèche (52) au-dessus de la couche
intermédiaire, la couche à effet de mèche comprenant une première région (62) ayant
un premier taux d'absorption d'humidité et une seconde région (64) ayant un second
taux d'absorption d'humidité qui dépasse le premier taux d'absorption d'humidité,
caractérisé en ce que le second taux d'absorption comprend des taux d'absorption longitudinal et latéral,
dont au moins le taux latéral est supérieur au premier taux d'absorption et le taux
d'absorption latéral dépasse le taux d'absorption longitudinal.
2. Support d'occupant selon la revendication 1, dans lequel la couche à effet de mèche
(52) est intégrée dans la couche intermédiaire (26, 30).
3. Support d'occupant selon la revendication 1 ou la revendication 2, dans lequel la
couche intermédiaire est une partie supérieure de contrôle de microclimat.
4. Support d'occupant selon la revendication 1 ou la revendication 3, dans lequel la
couche à effet de mèche (52) est fixée de manière amovible à la couche intermédiaire
(26, 30).
5. Support d'occupant selon la revendication 1 ou la revendication 3, dans lequel la
couche à effet de mèche (52) est fixée de manière non amovible à la couche intermédiaire
(26, 30).
6. Support d'occupant selon la revendication 1 ou la revendication 3, dans lequel la
couche à effet de mèche comprend un matériau (84, 86) relié à la couche intermédiaire
(30) par un adhésif perméable à la vapeur (88).
7. Support d'occupant selon la revendication 1 ou la revendication 3, dans lequel la
couche à effet de mèche est un revêtement perméable à la vapeur (100, 102).
8. Support d'occupant selon la revendication 1 ou la revendication 3, dans lequel la
couche à effet de mèche se présente sous la forme d'une feuille ajustée (52).
9. Support d'occupant selon l'une quelconque des revendications 1 à 8, dans lequel la
première région (62) est une région périmétrale qui délimite la seconde région (64).
10. Support d'occupant selon l'une quelconque des revendications 1 à 9, dans lequel la
seconde région (64) n'est pas rectangulaire.
11. Support d'occupant selon l'une quelconque des revendications 1 à 10, dans lequel la
vitesse d'absorption de la seconde région (64) n'est pas uniforme.