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(11) | EP 0 724 396 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
ZONED CELLULAR CUSHION IN ABSCHNITTE UNTERTEILTES ZELLENKISSEN COUSSIN ALVEOLAIRE A ZONES |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] The present invention concerns a cellular cushion according to the precharacterizing portion of claim 1.
[0002] This invention relates in general to inflatable mattresses and cushions, and more particularly to an inflatable mattress or cushion having normally isolated zones and a series of valves for placing its normally isolated zones selectively in communication with each other and with atmosphere.
[0003] Those individuals who are confined to wheelchairs run the risk of tissue breakdown and the development of pressure sores, which are extremely dangerous and difficult to cure. Typically much of the individual's weight concentrates in the regions of the ischia, that is at the bony prominences of the buttocks, and unless frequent movement occurs, the flow of blood to the skin tissue in these regions decreases to the point that the tissue breaks down. Cushions which are especially designed for wheelchairs exist for reducing the concentration of weight in the region of the ischia, and these cushions generally seek to distribute the user's weight more uniformly over a larger area of the buttocks.
[0004] Cellular cushions provide the most uniform distribution of weight and thus provide the greatest protection from the occurrence of pressure sores. These cushions have an array of closely spaced air cells which project upwardly from a common base. Within the base the air cells communicate with each other, and thus all exist at the same internal pressure. Hence, each air cell exerts essentially the same restoring force against the buttocks, irrespective of the extent to which it is deflected. US-A- 4,541,136 shows a cellular cushion currently manufactured and sold by ROHO, Inc., of Belleville, Illinois, for use on wheelchairs.
[0005] The WO-A-9207492 discloses a cellular cushion comprising a base, cells channels connected to a manifold and a means for blocking the channels.
[0006] The publication of the Roho Quadtro Cushion 1988 discloses a cellular cushion, air cells, flexible hoses connected to the air cells and means for blocking the hoses.
[0007] In a sense the typical cellular cushion provides a highly displaceable surface which tends to float the user. While this reduces the incidence of pressure sores, it detracts from the stability one usually associates with a seating surface. Most of those confined to wheelchairs have little trouble adjusting to the decrease in stability, but for those who have skeletal deformities particularly in the region of the pelvis and thighs, and for those who lack adequate strength in their muscles, lesser stability can be a source of anxiety. A variation of the ROHO cellular cushion addresses this problem with totally isolated zones and also cells of varying height. By varying the pressure between zones, one can accommodate for skeletal deformities while still maintaining satisfactory protection against pressure sores. US-A- 4,698,864 shows a zoned cellular cushion with cells of varying height.
[0008] Typically, a zoned cellular cushion has a separate filling stem and valve for each of its zones. The user simply opens the valve of each stem and introduces air into the zone for that stem, usually with a hand pump, and then releases the air from the zones until the desired posture is achieved. In a more sophisticated arrangement, a hose kit connects a single pump to a manifold which in turn is connected to the several valves through separate hoses. These hoses are fitted with separate hose clamps so that the air from the pump may be directed to the cells of the individual zones independently, and likewise the air can be released from them independently, all by manipulating the clamps. The hoses of the hose kit lie externally of the cushion and may become entangled in components of a wheelchair. Furthermore, by reason of their remote location, the hose clamps are difficult to manipulate.
[0009] Even more traditional inflatable cushions derive advantages from zoning, that is from being divided into zones or compartments which can be isolated from each other to accommodate skeletal deformities.
[0010] US-A-5 163 196 describes a valve for a zoned inflatable cushion such that access to all of the zones is cut-off simultaneouly because the valve is in a flap which is part of the cushion base and all of the access channels run through the flap.
[0011] The present invention is an improvement on the prior cushions which utilize a series of hoses to inflate the cushion in that it positions the bodies of the hoses within the periphery of the cushion and gathers the ends of all of the hoses in close proximity adjacent to one edge so that they do not become entangled in the wheelchair and are readily accessible to the user. It also is an improvement on US-A-5 163 196 in that the zones can be adjusted simultaneouly or selectively.
[0012] The present invention also resides in providing access to the cushion zones from beneath the cushion. A further advantage of the present invention is in providing access to the underside of the cushion and also to each cell of the cushion whereby pressure in each cell of the cushion can be monitored from a remote location.
[0013] This invention is equally appliable to inflatable mattresses, but will be described in connection with a wheelchair cushion.
[0014] These and other objects and advantages of the present invention will become apparent hereinafter.
[0015] The cellular cushion of the present invention is defined in the characterizing portion of claim 1.
[0016] In the accompanying drawings which form part of the specification and wherein like numerals and letters refer to like parts wherever they occur:
Fig. 1 is a top perspective view of a cushion embodying the invention;
Fig. 2 is a bottom plan view of the cushion shown in Fig. 1;
Fig. 3 is a fragmentary sectional view taken along lines 3-3 of Fig. 2;
Fig. 4 is a fragmentary sectional view taken along lines 4-4 of Fig. 2.
[0017] Referring now to the drawings (Fig. 1), A designates a cellular cushion of the present invention which is highly flexible and is designed for use on an underlying supporting surface, such as, the seat of a wheelchair or the seat of a conventional chair. Being cellular, the cushion A distributes the weight of its occupant generally uniformly over the entire area of the buttocks and thereby dissipates the pressures resulting from the supported weight at the ischia, that is, at the bony prominences of the buttocks. It further has the capacity to position and stabilize the user.
[0018] The cushion A includes (Fig. 1) a base 2 and air cells 4 which project upwardly from the base 2. Both the base 2 and the air cells 4 are preferably molded or otherwise formed from highly flexible neoprene. The base 2 is rectangular and the cells 4 are arranged on it in longitudinal rows and transverse rows, with each cell 4 occupying both a longitudinal row and a transverse row. The cells 4 are further arranged in zones, typically, four zones r, s, t, and u. The zones r and s lie side by side at the front of the cushion A, whereas the zones t and u exist side by side at the rear of the cushion A. The right zones r and t are separated from the left zones s and u along a longitudinal axis x-x, whereas the front zones r and s are separated from the rear zones t and u along a transverse axis y-y. More or less zones and differing arrangements of those zones may be employed.
[0019] Within the base 2, the cells 4 of the zone r communicate with each other, so that all exist at the same internal pressure irrespective of how far they are depressed. The same holds true with regard to the cells 4 of the zone s, the cells 4 of the zone t, and the cells 4 of the zone u. However, the cells 4 of the zone r normally do not communicate with the cells 4 of the zones s, t and u, or in other words the cells 4 of the zone r are normally isolated from the cells of the remaining zones s, t and u. Likewise the cells 4 of the zone s are normally isolated, as are the cells of the zones t and u. Thus, the cells 4 of each zone r, s, t and u collectively enclose a separate compartment.
[0020] Connected to each of the zones r, s, t and u are fill tubes 20, 21, 22 and 23, respectively. These are flexible and tubular in cross-section. These terminate in close proximity to each other adjacent to, but outwardly of one edge of the cushion A. Preferably they come out from beneath the front edge of the cushion A so they are accessible to the wheelchair user. The free ends of the tubes 20, 21, 22 and 23 are connected to a manifold 24 to which is connected a fill nozzle 25 having a shut off valve 26 (Fig. 1). The fill tubes 20, 21, 22 and 23 are all connected to the zones r, s, t and u through the underside of the cushion A. By passing beneath the cushion A, the fill tubes 20, 21, 22 and 23 provide access to the zones r, s, t and u for pressure monitoring devices. Also, there can be tubes or similar monitoring devices connected to each of the individual cells 4 through the underside of the cushion A so that a complete dynamic pressure profile of the patient can be taken at a remote location at any given point in time.
[0021] Positioned on each of the tubes 20, 21, 22 and 23 adjacent to the manifold 24 are cut-off clamp type hose valves 30. The valves 30, as shown, comprise a base 31 having an upstanding lock post 32. A spring arm 33 is connected to and overlies the base 31. The arm 32 has a knife edge nose 34 which is designed to engage notches 35 on the post 32 to lock the arm 33 to the notch 35 when in cut-off position. Cut-off members 36 and 37 are on the base 31 and the arm 33 respectively. The cut-off members 36,37 are aligned, and when the nose 34 and lock notches 35 are engaged, move toward each other to force the tube sides together into linear sealing alignment to thereby block the tube and close off flow of air or other fluid through the fill tubes 20, 21, 22 and 23. The fill tubes 20, 21, 22 and 23 pass through the arm 33 and the lock post 32 by means of ports 38, 38a, respectively. These manually operated valves can be replaced with electrically operated solenoid valves which would permit sequential operation.
Operation
[0022] In order to prepare the cushion A for the user, the valves 30 are opened. This places the interiors of the cells 4 for the four zones r, s, t and u in communication through the mainfold 24. Air is pumped into the cushion through the valve 26. Since the cells 4 of the zones r, s, t and u are in communication through the manifold 24, all of the cells 4 are inflated. The cells 4 reach a state of equilibrium in a short time. Enough air is pumped into the cushion A to exceed the requirements for supporting the user. The valve 26 is then closed and the pump removed.
[0023] Next the overinflated cushion A is placed on the supporting surface upon which it is to rest when supporting the user, and that could be a wheelchair seat or the seat of a traditional chair. The user then sits upon the cushion A in the location he expects to assume and slowly releases air from the filling valve 26 to immerse the user. As the air is released, the user's buttocks sink deeper and deeper into the array of air cells 4, and they tend to envelope and assume the contour of the buttocks. Enough air is released to bring the region of the ischia to within about 1.27cm(1/2inch) of the base 2. Of course, as the air flows out of the cushion A, all of the cells 4 remain at essentially the same internal pressure, because they are all interconnected through the open manifold 24. When the user achieves the desired immersion, the filling valve 26 is closed.
[0024] While immersed in the cells 4 of the cushion A, the user moves or is moved by others to the posture desired to be maintained for an extended period, and this causes a redistribution of air amongst the cells 4 of the several zones r, s, t and u. In time, the cells 4 of the several zones r, s, t and u reach equilibrium, that is to say the flow between the zones r, s, t and u ceases. At this time, the individual valves 30 are closed to prevent air from flowing between the zones r, s, t and u.
[0025] The isolated zones r, s, t and u impart stability to the cushion A, and this serves to maintain the user in the selected posture. Thus, if the user attempts to assume a different posture, he will encounter greater resistance from cells 4 of one of more of the zones r, s, t and u, and they will urge the user back to the initial posture. The capacity to maintain a selected posture or to urge the user to such a posture is particularly useful with users who suffer from spinal deformities and for those whose muscles have atrophied.
[0026] To further adjust the position of the user on the cushion, the valve 26 is opened and the individual cut-off valve 30 to the zone which is to be adjusted also is opened. Air can be added to or bled from the selected zone selectively without involving the other zones.
[0027] An alternative construction provides for individual fill valves 40 on each of the zones r, s, t and u. The valves 40 make it easier to test each quadrant or zone for leaks in the assembly process and also to separately fill or bleed each zone.
1. A cellular cushion (A) comprising a flexible nonrigid base (2) having front, rear
and side edges, a plurality of flexible and hollow air containing cells (4) attached
to and projecting away from the base (2), the cells (4) being organized into zones
(r,s,t,u) with the interiors of the cells (4) for each zone within the region of the
zone being in communication through the base (2), but not with the air cells of the
other zones, a manifold (24) located adjacent the one edge of the base (2) and positioned
outwardly from the base edge, a separate channel (20,21,22,23) for each zone (r,s,t,u)
with each channel (20,21,22,23) extending between at least one cell (4) of its zone
and the manifold (24), the channels (20,21,22,23) being connected to the cushion cells
(4) through the base (2) of the cushion and the channels (20,21,22,23) extending along
the underside of the base (2) within the periphery of the cushion (A) until they come
together and join the manifold (24), whereby the cells (4) of the different zones
(r,s,t,u) communicate only through the manifold (24), and means for selectively blocking
the channels (20,21,22,23) independently of the manifold (24) so that the cells (4)
of the different zones (r,s,t,u) can be adjusted independently, characterized in that
the channels (20,21,22,23) have flexible and tubular shaped portions which are juxtaposed
near the midpoint of an edge of the base and the manifold is integral with the channels
and separate from and independent of the base, and the air blocking means are clamps
(30) positioned on the tubular members between the edge of the base and the manifold,
the clamps compressing the flexible tubes (20,21,22,23) together so that the interiors
of the tube walls are flattened and form a linear seal across the tube.
2. The cushion (A) of claim 1 characterized in that each of the zones (r,s,t,u) has independent
means (40) for introducing air into and bleeding air from said zone.
3. The cellular cushion (A) according to claim 1 characterized by each channel (20,21,22,23)
extending from the bottom of at least one cell (4) of its zone (r,s,t,u) along the
underside of the cushion (A) and past an edge of the cushion (A), whereby the cells
(4) of the different zones (r,s,t,u) do not communicate with each other and access
to the individual cells (4) is had to monitor the fluid pressure in the zones (r,s,t,u)
remotely from the cells.
4. The cushion (A) of claim 2 characterized in that the independent means are fill valves
(40) for each zone (r,s,t,u).
5. The cushion (A) of claims 1-4 characterized in that the portions of the channels (20,21,22,23)
which extend past the cushion edges are tubular and flexible and include means for
squeezing the tube walls together into linear engagement to seal the tubes and stop
fluid flow therethrough.
6. The cushion (A) of claim 5 characterized in that the channels (20,21,22,23) which
extend past the cushion edges are in close juxtaposition.
1. Zellkissen (A), umfassend eine flexible, nicht steife Basis (2) mit Vorder-, Rück-
und Seitenkanten, eine Vielzahl von flexiblen und Luft enthaltenden Hohlzellen (4),
angefügt an und von der Basis (2) wegragend, wobei die Zellen (4) in Zonen (r, s,
t, u) organisiert sind, wobei das Innere der Zellen (4) für jede Zone innerhalb der
Region der Zone in Verbindung durch die Basis (2) aber nicht mit den Luftzellen der
anderen Zonen ist, einen Verteiler (24), angeordnet benachbart zu der einen Kante
der Basis (2) und nach außen liegend von der Basiskante positioniert, einen getrennten
Kanal (20, 21, 22, 23) für jede Zone (r, s, t, u), wobei jeder Kanal (20, 21, 22,
23) sich zwischen mindestens einer Zelle (4) ihrer Zone und dem Verteiler (24) erstreckt,
wobei die Kanäle (20, 21, 22, 23) an die Kissenzellen (4) durch die Basis (2) des
Kissens verbunden sind, und die Kanäle (20, 21, 22, 23) erstrecken sich entlang der
Unterseite der Basis (2) innerhalb der Peripherie des Kissens (A), bis sie zusammenkommen
und sich dem Verteiler (24) anschließen, wodurch die Zellen (4) der unterschiedlichen
Zonen (r, s, t, u) nur durch den Verteiler (24) in Verbindung stehen, und Mittel zum
selektiven Blockieren der Kanäle (20, 21, 22, 23) unabhängig von dem Verteiler (24),
so daß die Zellen (4) der unterschiedlichen Zonen (r, s, t, u) unabhängig eingestellt
werden können, dadurch gekennzeichnet, daß die Kanäle (20, 21, 22, 23) flexible und
röhrenförmig geformte Teile haben, welche in Nebeneinanderstellung nahe dem Mittelpunkt
einer Kante der Basis sind, und der Verteiler ist integral mit den Kanälen und getrennt
und unabhängig von der Basis, und die Luftblockierungsmittel sind Klammern (30), angeordnet
auf den röhrenförmigen Gliedern zwischen der Kante der Basis und dem Verteiler, wobei
die Klammern die flexiblen Röhren (20, 21, 22, 23) zusammendrücken, so daß die Innern
der Röhrenwände flachgedrückt sind und einen linearen Verschluß über der Röhre bilden.
2. Kissen (A) nach Anspruch 1, dadurch gekennzeichnet, daß jede der Zonen (r, s, t, u)
unabhängige Mittel (40) zum Einführen von Luft in und Blasen von Luft aus der Zone
hat.
3. Zellkissen (A) nach Anspruch 1 gekennzeichnet durch jeden Kanal (20, 21, 22, 23),
der sich von dem Boden von mindestens einer Zelle (4) ihrer Zone (r, s, t, u) entlang
der Unterseite des Kissens (A) und über eine Kante des Kissens (A) hinaus erstreckt,
wobei die Zellen (4) der unterschiedlichen Zonen (r, s, t, u) nicht miteinander in
Verbindung stehen, und Zugriff zu den einzelnen Zellen (4) ist, den Flüssigkeitsdruck
in den Zonen (r, s, t, u) entfernt von den Zellen zu kontrollieren.
4. Kissen (A) nach Anspruch 2, dadurch gekennzeichnet, daß die unabhängigen Mittel Füllventile
(40) für jede Zone (r, s, t, u) sind.
5. Kissen (A) nach Ansprüchen 1-4, dadurch gekennzeichnet, daß die Teile der Kanäle (20,
21, 22, 23), welche sich über die Kissenkanten hinaus erstrecken, röhrenförmig und
flexibel sind und Mittel zum Zusammendrücken der Röhrenwände in linearer Stellung
zum Verschließen der Röhren und Beendigen des Flüssigkeitsflusses dadurch einschließen
6. Kissen (A) nach Anspruch 5, dadurch gekennzeichnet, daß die Kanäle (20, 21, 22, 23),
welche sich über die Kissenkanten hinaus erstrecken, in enger Nebeneinanderstellung
sind.
1. Un coussin alvéolaire (A) comprenant une base non rigide flexible (2) ayant des bords
avant, arrière et latéraux, une pluralité d'alvéoles (4) flexibles et creuses contenant
de l'air fixées à et se projetant vers le haut à partir de la base (2), les alvéoles
(4) étant organisées en zones (r,s,t,u), les intérieurs des alvéoles (4) de chaque
zone dans la région de la zone étant en communication par l'intermédiaire de la base
(2), mais pas avec les alvéoles d'air des autres zones, un collecteur (24) positionné
adjacent à un bord de la base (2) et positionné à l'extérieur du bord de la base,
un conduit séparé (20,21,22,23) pour chaque zone (r,s,t,u) chaque conduit (20,21,22,23)
s'étendant entre au moins une alvéole (4) de sa zone et le collecteur (24), les conduits
(20,21,22,23) étant reliés aux alvéoles (4) du coussin par l'intermédiaire de la base
(2) du coussin et les conduits (20,21,22,23) s'étendant le long du côté inférieur
de la base (2) à l'intérieur de la périphérie du coussin (A) jusqu'à ce qu'elles viennent
ensemble et se joignent au collecteur (24), où les alvéoles (4) des zones différentes
et (r,s,t,u) communiquent seulement par l'intermédiaire du collecteur (24), et un
dispositif pour bloquer sélectivement les conduits (20,21,22,23) indépendamment du
collecteur (24) de sorte que les alvéoles (4) des différentes zones (r,s,t,u) peuvent
être ajustées de manière indépendante, caractérisé en ce que les conduits (20,21,22,23)
comportent des parties flexibles et en forme de tube qui sont juxtaposées près du
point central de chaque bord de la base et le collecteur fait partie intégrante avec
les conduits et est séparé de et est indépendant de la base, et le dispositif de blocage
d'air est constitué de clamps (30) positionnés sur les éléments tubulaires entre le
bord de la base et le collecteur, les clamps comprimant les tubes flexibles (20,21,22,23)
ensemble de sorte que les intérieurs des parois des tubes sont applatis et forment
un joint linéaire au travers du tube.
2. Le coussin (A) de la revendication 1 caractérisé en ce que chaque zone (r,s,t,u) comporte
un dispositif indépendant (40) pour introduire de l'air dans ou faire sortir de l'air
de cette zone.
3. Le coussin alvéolaire (A) selon la revendication 1 caractérisé par chaque conduit
(20,21,22,23) s'étendant depuis la base d'au moins une alvéole (4) de sa zone (r,s,t,u)
le long du côté inférieur du coussin (A) et audelà d'un bord du coussin (A), de sorte
que les alvéoles (4) des différentes zones (r,s,t,u) ne communiquent pas l'une avec
l'autre et l'accès vers les alvéoles individuelles (4) doit régler la pression du
fluide dans les zones (r,s,t,u) à un endroit éloigné des alvéoles.
4. Le coussin (A) de la revendication 2, caractérisé en ce que le dispositif indépendant
est constitué de valves de remplissage (40) pour chaque zone (r,s,t,u).
5. Le coussin (A) des revendications 1-4 caractérisé en ce que les parties des conduits
(20,21,22,23) qui s'étendent au-delà des bords du coussin sont tubulaires et flexibles
et comprennent un dispositif pour aplatir les parois du tube ensemble en contact linéaire
pour sceller les tubes et arrêter l'écoulement du fluide au travers.
6. Le coussin (A) de la revendication 5 caractérisé en ce que les conduits (20,21,22,23)
qui s'étendent au-delà des bords du coussin sont en juxtaposition étroite.