CA2166106C - Improved anatomical support apparatus - Google Patents

Abstract

An improved anatomical support apparatus (200) including an upper substrate (206) engageable with a body surface of a user, and a support substrate (208) attached to the upper substrate. The upper substrate (206) has a first honeycomb core formed of undulated strips of resilient thermoplastic material, thermal compression bonded together to form cell walls defining a plurality of contiguous regularly shaped cells. Each of the cell walls has an upper extremity and a lower extremity. Each upper (250) and lower (252) extremity of the first core forms either a planar or a contoured surface (214).

Description

2 PCT/US94/07229 1 Specification

3 "IMPROVED ANATOMICAL SUPPORT APPARATUS"

4 $ACRGROUND TO THE INVENTION

t 7 Bield of the Invention 8 T~~e present invention relates generally to anatomical 9 support apparatus, and more particularly to mattresses and seat cushions having at least one thermoplastic 11 elastomeric honeycomb panel.

13 Description of the Prior Art 14 Substantially immobile people (i.e. wheelchair bound users) have a great need for support cushions that 16 minimize the development of decubitus ulcers (i.e.

17 bedsores) that can occur during long periods of 18 confinements to beds or chairs.

19 Traditionally, foam and gel-filled materials have been used in seat cushions to absorb shock, reduce 21 pressure, and provide support for wheel chair users.

22 There are many prior art seat cushions that are comprised 23 of a foam cushion encased within a washable covering, 24 wherein the foam cushion is formed so as to provide a comfortable seating surface. For example, the foam 26 cushion may have a cut-out or contact-free zone formed 27 through it to reduce pressure on the user's spine, coccyx 28 (i.e. tailbone), or ischial tuberosities, or to eliminate 29 physical contact between the cushion and particularly sensitive portions of the user's body.

31 In other devices, the foam is specially tapered or 32 shaped to enable the user to easily rise from the seat.

33 Shaping the foam in such cushions helps reduce high 34 pressure areas and positions the user for posturing, but .0 35 only if the user's anatomy fits the contours of the shaped 36 foam. High pressure points will still occur if the user 37 has an anatomy that does not conform to the contours of 38 the shaped foam. This is frequently the case when the _ -2-1 user is an amputee, or is improperly positioned on the 2 cushion, or is changing positions on the cushion.
3 In yet other prior art devices, a gel or other fluid-4 like substance fills an impermeable sack which is disposed within or on a foam envelope. The entire assembly is 6 encased within a moisture resistant cloth, vinyl and/or r 7 urethane, or waterproof covering and placed on a seat as 8 a seat cushion. In some cases the gel-filled cushion is 9 formed with contours or contact-free zones to relieve contact and pressure on sensitive portions of the user's 11 body. For example, U.S. Patent 5,191,752 discloses a seat 12 cushion formed from silicon dielectric gel is used in an 13 equestrian saddle. The gel cushion, although somewhat 14 shock absorbent, is heavy and prone to damage from punctures and the like. In U.S. Patent 5,201,780 a tri-16 layered mattress pad is disclosed. The pad includes a 17 cover or casing containing an interior strata of a plastic 18 film layer atop a fluid bladder layer supported on a foam 19 layer. The pad is designed to reduce the development of bedsores by reducing normal and lateral pressures and 21 forces on the bed user. As discussed below, there are 22 disadvantages associated with foam and gel-filled 23 materials.
24 One problem associated with gel materials is that they retain heat. During periods of continuous contact 26 with a user's body, the temperature and moisture in the 27 contact areas between the gel-filled cushion and the 28 user's body also increases. An elevated gel material 29 temperature causes user discomfort and exacerbates any existing injuries (e.g. bedsores) the user may have. The 31 moisture increase also creates an unsanitary condition for 32 the user because bacterial growth in the contact area is 33 promoted and the user's injuries are likely to become .
34 infected. ' Secondly, gel-filled cushions disposed in the 36 wheelchairs of athletic users are especially 37 uncomfortable. During outdoor athletic activity (i.e.
38 during exposure to sunlight) or during periods of physical 39 exercise, the temperature of the gel material reaches and WO 95100052; PCT/US94/07129 1 remains at high levels. The gel material remains hot even 2 when the user stops exercising and is attempting to cool 3 down. Also, in cold weather, the gel freezes into a solid 4 or semi-solid state.

In a gel-filled cushion, the gel tends to move (i.e.

6 spread) away from the area under load. The user of the V , 7 cushion, or his assistant, is required to "knead" (i.e.

8 push) the gel back into the proper location beneath the 9 user's body. This is a tiring, difficult, and l0 inconvenient activity.

11 Another shortcoming of using gel-filled cushions is 12 that the impermeable sack which contains the gel can have 13 a hammocking effect on the user's prominences. This 14 causes high pressure zones beneath the protruding areas resulting in sores or other injury.

16 Finally, gel-filled cushions are relatively heavy, 17 and especially vulnerable to damage or destruction from 18 puncturing.

19 In addition, there are shortcomings associated with foam materials which, for example, are susceptible to 21 taking a compression set after many periods of use. It is 22 tyL~ical, that after a prolonged period of use the foam 23 cells collapse and the support benefit of the cushion is 24 lost. Also, foams cushions must be encased within impermeable coverings because they readily absorb fluids.

26 The foam cushion must be replaced if incontinence or an 27 accidental spill wets a cushion with a torn covering.

28 Some wheelchair cushions utilize pneumatic devices as 29 a pressure relieving system for reducing ischemic injury.

U.S. Patent 5,193,237, for example, discloses a pneumatic 31 wheelchair cushion having a number of separate unattached 32 air sacks arranged in a matrix. Reduced airflow and 33 therefore reduced air pressure is periodically provided 34 within the cushion so that each air sack will have reduced pressure for a predetermined period of time. A self-36 regulating air distribution is provided such that when the 37 occupant shifts his/her weight so as to overcome the air 38 pressure in a sack, the system automatically backflows air 39 into that particular sack thereby cushioning the user.

1 The disclosed wheelchair device is complex, and 2 requires electrical power and pressurized air. Such 3 devices are overly complicated, costly to acquire, and 4 costly to maintain. Also, the air cushion device must be frequently adjusted, can be punctured, and is unstable for 6 a user.
Y
7 In addition, there are some prior art mattresses that 8 include a matrix of air cells that are inflated and 9 deflated to more evenly support bodies and reduce the development of bedsores. In addition to the air supply 11 components (e. g. compressor, valuing, tubing, etc.) these 12 mattresses also require a computer to constantly measure 13 the resistance in each air cell and to control the 14 reaction of each cell to pressure and load changes by varying the deflation and inflation in each cell. These 16 devices are also costly, complicated, require adjustment, 17 and subject to puncture damage.
18 The prior art also discloses resilient honeycomb 19 structures used in personal-use items. U.S. Patents

5,134,790 and 4,485,568 disclose using resilient honeycomb 21 structures in the sole of shoes. Also, U.S. Patent 22 4,422,183 to Landi et al. discloses a protective body 23 shield having a honeycomb structure constructed from a 24 resilient flexible material. Finally, U.S. Patent 5,203,607 discloses an improved bicycle seat including a 26 rigid shell supporting a foam layer having a pad of 27 thermoplastic elastomer honeycomb disposed within or 28 thereon. In all of these devices, the honeycomb 29 structures are not utilized in seat cushions and mattresses.
31 Thus, there is a need to provide an improved 32 anatomical support apparatus that maximizes pressure 33 relief, stability, comfort, durability, maintainability, 34 and weight, yet does not possess the short-comings of the presently employed devices.

2 Obieats of this Invention 3 It is therefore an object of the present invention to 4 provide an improved anatomical support apparatus that provides improved pressure relief and stability

6 characteristics, significant compression set resistance,

7 durability, low weight, and low maintenance properties.

8 It is another object of the present invention to

9 provide an improved anatomical support apparatus having at least one thermoplastic elastomer honeycomb panel that 11 conforms, supports, and stabilizes a wide variety of 12 sitting positions, user anatomies and disabilities.

13 It is still another object of the present invention 14 to provide an improved anatomical support apparatus that is breathable to permit cooling of the user.

16 Another object of the present invention is to provide 17 an improved anatomical support apparatus that can be 18 tailored to create the desired cushioning and stabilizing 19 characteristics without having to introduce elements such as foam, fluids or other elements which add cost or reduce 21 durability.

22 Still another object of the present invention is to 23 provide an improved anatomical support apparatus 24 constructed of materials that are fast drying, and can be easily disinfected and sterilized by chemical wash, 26 microwave, detergent, or other means.

27 Another object of the present invention is to provide 28 an improved anatomical support that has at least one 29 flexible thermoplastic elastomeric honeycomb having at least one contoured surface engagable with a body area of 31 a user.

32 Briefly, an improved anatomical support apparatus 33 includes a frame for supporting the apparatus, an outer 34 envelope and a resilient inner body encased within the envelope, both the inner body and the outer envelope 36 resting on the frame. The inner body including a first 3 7 panel having at least one honeycomb core , f first and second 38 facing sheets. The core is formed of undulated strips of 39 resilient thermoplastic material, thermal compression WO 95/00052 - ~ PCT/IJS94/07129 1 bonded together to form cell walls defining a plurality of 2 contiguous regularly shaped cells. The first facing sheet 3 is formed of resilient thermoplastic material that is 4 thermal compression bonded to an upper face of the core formed by upper extremities of the cell walls. The 6 bonding is accomplished by simultaneously applying heat 7 and pressure to the joinder of the first facing sheet and 8 the core. The second facing sheet is similarly formed 9 from resilient thermoplastic material and is thermal compression bonded to a lower face of the core formed by 11 lower extremities of the cell walls, the bonding being 12 accomplished by simultaneously applying heat and pressure 13 to the joinder of the second facing sheet and the core.
14 The core anisotropically flexes to stabilize and spread the load exerted by the user.
16 In an alternate embodiment of the present invention, 17 an improved anatomical support apparatus includes at least 18 one contoured substrate and at least one planar substrate 19 attached to the contoured substrate. The contoured substrate includes a first honeycomb core formed of 21 undulated strips of resilient thermoplastic material, 22 thermal compression bonded together to form cell walls 23 defining a plurality of contiguous regularly shaped cells.
24 Each of the cell walls having an upper extremity and a lower extremity, and at least one of the upper and the 26 lower extremity forming a contoured surface. The 27 contoured substrate further includes means for maintaining 28 the first core in its expanded configuration. The planar 29 substrate is attached to one of the upper and the lower extremity of the first core, and includes a second 31 honeycomb core formed of undulated strips of resilient 32 thermoplastic material, thermal compression bonded 33 together to form cell walls defining a plurality of , 34 contiguous regularly shaped cells. Each of the cell walls having an upper extremity and a lower extremity, each of , 36 the upper and the lower extremity forming a planar 37 surface. In addition, the planar substrate also includes 38 means for maintaining the second core in its expanded 39 configuration. The first and the second cores being 1 anisotropically flexible and capable of stabilizing and 2 spreading a load exerted thereupon by said user of the 3 cushion.

4 An important advantage of the present invention in that the thermoplastic elastomer honeycomb panel used in 6 the construction of the apparatus is an anisotropic 7 material having improved pressure relief, stability, 8 compression set resistance, durability and low maintenance 9 characteristics.

Another advantage of the present invention is that 11 single or multiple thermoplastic elastomer honeycomb 12 panels may be configured within the anatomical support 13 apparatus to customize and individually tailor it for an 14 individual user.

Yet another advantage of the present invention is 16 that an anatomical support apparatus can support and 17 conform to a wide range of user support positions, user 18 anatomies and disabilities.

19 Yet still another advantage of the present invention is that entire or only portions of the anatomical support 21 apparatus may be pressurized to create different support 22 and stability characteristics.

23 Yet another advantage of the present invention is 24 that the anatomical support apparatus may be constructed from a perforated core thermoplastic elastomer honeycomb 26 panel and perforated faces that is breathable to allow 27 perspiration removal and cooling of the apparatus user.

28 Another advantage of the present invention is that 29 different thermoplastic elastomer honeycomb core designs or multiple panels of different thermoplastic honeycomb 31 core designs may be utilized to maximize design 32 flexibility of the improved anatomical support apparatus.

33 Still another advantage of th=..= present invention is 34 that the thermoplastic elastome~- honeycomb core is fabricated from recyclable materials that are fast drying, 36 and easily disinfected and sterilized.

37 These and other objects and advantages of the present 38 invention will no doubt become apparent to those skilled 39 in the art after having read the following detailed _g_ 1 description of the preferred embodiment which is contained 2 in and illustrated by the various drawing figures.

In the accompanying drawings:
6 Fig. 1 is a perspective view illustrating a 7 wheelchair having disposed thereon an improved anatomical 8 support cushion constructed in accordance with a preferred 9 embodiment of the present invention;
Fig. 2 is a perspective view illustrating a 11 thermoplastic honeycomb panel of the type utilized in the 12 improved anatomical support cushion shown in Fig. 1, 13 wherein the panel has a non-perforated honeycomb core;
14 Fig. 3 is a partial cross-section taken through the line 3-3 of the panel illustrated in Fig. 1 to illustrate 16 the structural characteristics of one embodiment of the 17 panel;
18 Fig. 4 is a partial cross-section illustrating an 19 alternative embodiment of the panel illustrated in Fig. 2;
Fig. 5 is a perspective view of another thermoplastic 21 honeycomb panel of the type utilized in the improved 22 anatomical support cushion shown in Fig. s, wherein the 23 panel is shown with a non-perforated facing sheet broken 24 away to reveal a perforated honeycomb core, and also illustrated is a separate section of the panel having a 26 perforated honeycomb core as well as a perforated facing 27 material;
28 Fig. 6 is a partially broken depiction of a 29 thermoplastic honeycomb panel, similar to the panel illustrated in Fig. 5, communicatively coupled to a bulb 31 pump;
32 Fig. 7 depicts a force deflection comparison plot 33 between a seat cushion utilizing foam or gel materials and 34 an improved cushion having a thermoplastic honeycomb panel of the present invention;
36 Fig. 8 illustrates the idealized honeycomb seating 37 cushion design parameters;

_9_ 1 Fig. 9 illustrates the buttressing effect of the 2 cells of a thermoplastic flexible honeycomb panel of the 3 present invention when loaded by a wheelchair user;

4 Fig. 1oA through 10E are cross-sectional views of the cushion illustrated in Fig. 1 wherein alternative 6 thermoplastic flexible honeycomb panel configurations are 7 illustrated;

8 Fig. 11 is a perspective view of a flexible 9 thermoplastic honeycomb panel of the type illustrated in Fig. 1, partially broken to show a flexible honeycomb core 11 insert disposed on a conventional foam cushion;

12 Fig. 12 is a cross-sectional view of the panel 13 illustrated in Fig. 11;

14 Fig. 13 is a perspective view of an improved anatomical support cushion having a foam layer and a 16 plurality of independent flexible thermoplastic honeycomb 17 pad sections that are fitted into cavities pre-formed 18 within the foam layer;

19 Fig. 14 is a perspective view of an improved anatomical support apparatus of the present invention used 21 in a bed disposed on a standard hospital bed frame;

22 Fig. 15 is an enlarged perspective view of the bed 23 including a mattress pad of the present invention; and 24 Fig. 16 is a cross-sectional view of the bed taken along the line 16-16 of Fig. 15;

26 Fig. 17 is a perspective view of an alternate 27 embodiment of the present invention including a cushion 28 having at lease one contoured substrate made from a 29 thermoplastic elastomeric honeycomb panel;

Fig. 1$ is a partial sectional view of one embodiment 31 of the cushion shown in Fig. 17, having a contoured upper 32 substrate;

33 Fig. 19 is a partial sectional view of another 34 embodiment of the cushion shown in Fig. 17, having a contoured intermediate substrate;

36 Fig. 20 is a partial sectional view of yet another 37 embodiment of the cushion shown in Fig. 17, having a 38 contoured upper substrate and a stiffened intermediate 39 substrate; and

-10-1 Fig. 21 is a partial sectional view of still another 2 embodiment of the cushion shown in Fig. 17, having a 3 contoured upper substrate and a facing sheet disposed 4 therein.

7 Referring now to Fig. 1 which depicts a conventional 8 wheelchair 10 having disposed thereon a removable improved 9 anatomical support cushion 12. As will be described in greater detail below, the cushion 12 is constructed of at

11 least one flexible thermoplastic elastomer honeycomb core

12 panel built in accordance with the present invention. It

13 should be noted that, although the cushion 12 is

14 particularly well suited for wheelchair applications, the cushion 12 may be used in a variety of other anatomical 16 support applications (e.g., mattresses, automobile and 17 airline seats, arm rests, seat belts, etc.).
18 Referring to Fig. 2 which illustrates a honeycombed 19 panel structure 14 constructed from thermoplastic - 20 elastomer materials. The panel 14 includes a honeycomb 21 like core preferably made of bonded together and expanded 22 strips or ribbons 16 of plastic material to which facing 23 sheets 18 and 20 of perhaps heavier gauge material are 24 thermocompression bonded. The panel is an anisotropic three-dimensional structure having predetermined degrees 26 of flex along the X, Y and Z axis. Each cell is formed, 27 in part, by four generally S-shaped wall segments each of 28 which is shared by an adjacent cell. In addition, each 29 cell shares a double thickness wall segment with two adjacent cells.
31 Panel 14 has high tear and tensile strength and is 32 highly resilient, with optimal compression load and shock 33 absorption or distortion characteristics yet is extremely , 34 light weight. Selected combinations of elastomer material, honeycomb cell configurations, core thickness 36 and facing material variables will determine the panel's 37 characteristics of softness or hardness, resilient 38 recovery rate and rigidity or flex as required for a 39 particular application. The facing materials can be WO 95/00052 _ -:, :y PCT/US94/07I29 1 selected from a wide variety of films, including 2 thermoplastic urethanes, foams, EVAs, rubber, neoprene, 3 elastomer impregnated fibers and various fabrics, etc.
4 The manufacturing and fabrication of the panel 14 is described in greater detail in our U.B. Patent 5,039,567 7 Fig. 3 is a cross-sectional view taken along the line 8 3-3 of Fig. 2. As illustrated, each wall of the core will 9 have a structure which resembles an I-beam, as indicated at 22, and upper and lower faces 24 and 26, either or both 11 of which may be deformed during a planarization operation 12 as disclosed in our above identified U.S. Patent to 13 stabilize the honeycomb core and prevent the expanded 14 strip from collapsing. The faces 24, 26 are firmly bonded to the facing sheets 18 and 20. In addition, as 16 illustrated in Fig. 2, each cell will be formed of four 17 generally S-shaped vertical wall segments 28 joined 18 together with two wall segments 30 and 32 of double 19 thickness. With the top and bottom edges of these walls bonded to the upper and lower facing sheets 18 and 20 a 21 unitary honeycomb panel is provided with no seams or 22 separations. Because of the high integrity of the bonds 23 between the core and facing sheets, the anisotropic 24 features of the structure will be uniform and predictable.
In addition, as illustrated in Fig. 4, a multi-cored 26 structure may be built up as depicted at 34. Such 27 structure car_ include different core configurations 36 and 28 38 as well as different types of facing materials 40, 41, 29 and 42. It will, of course, be appreciated that within a 30~ single core cell, dimensions may be varied by changing the 31 dimensions and/or spacings of the bonding ribs used during 32 the build-up of the core stack.
33 Fig. 5 is a perspective view of a perforated core (or 34 perforated cell wall) honeycomb panel 44. The panel 44 is broken into two sections, a left hand section 45 and a 36 right hand section 46 in order to more fully illustrate 37 alternative embodiments. The left half 45 shows material 38 having a perforated honeycomb core 48 and unperforated or 39 solid facing sheets 49 and 50. The dashed lines 51 WO 95/00052 ~._ ,Y;~ ' PCTlUS94107129 1 illustrate the normal full coverage of the top facing 2 sheet 49.
3 The honeycomb core 48 is made from sheets of a 4 selected grade thermoplastic elastomeric material that has been perforated such that a matrix of small holes 59 6 exists throughout. The sheets are compression bonded 7 together in spaced intervals staggered between alternating 8 sheets as described in our U.S. Patent 5,039,567. The resulting stack is 9 then cut into strips which, when expanded, create a '' honeycomb network of elongated, generally hexagonally 11 I shaped cells 52.
12 Each cell 52 of the honeycomb-core 48 is defined by 13 four generally S-shaped wall segments, each interior wall 14 of which is shared by an adjacent cell. The wall segments of each cell 52 include a single thickness wall portion 54 16 and a double thickness wall portion 56.
17 The upper and lower faces 58 and 60 of the walls 18 forming several cells are deformed during a planarization I9 operation as disclosed in our above-identified U. S . Patent to stabilize the honeycomb core and prevent the expanded 21 strip stock from collapsing. Facing sheets 49 and 50, cut 22 from sheets of resilient thermoplastic material, are then 23 compression banded to the upper and lower faces 58 and 60.
24 The addition of the facing sheets 49 and 50 strengthens the core 48 and provides an ample surface for adhering 26 another panel or other material.
27 The right half section 46 of the panel depicted in 28 Fig. 5 includes a perforated honeycomb core 47 similar to 29 the left hand section 45 of the panel, but has facing 30~ sheets 55 and 53 made of perforated material. Dashed 31 lines 57 indicate the honeycomb pattern of the core 47 32 underneath the top facing sheet 55. By perforating both 33 the honeycomb core and facings, the weight of the material 34 is reduced while the resiliency and flexibility is increased. The weight is reduced because the perforations 36 reduce the overall quantity of the material comprising the 37 honeycomb and facings. Similarly, the flexibility is 38 increased because there is less material to constrain each WO 95/00052 : PCT/TJS94/07129 1 segment of the material from bending. The resiliency, or 2 ability of the structure to spring back to its original 3 form after being compressed, is also enhanced by virtue of 4 the additional passages through which air can return to fill the cells. It will be appreciated that the resilient 6 but damped restorative characteristics of the~structure 7 make it an excellent absorber of shock waves.
8 Referring now to Fig. 6 which depicts a pressurized 9 honeycomb panel 62 including a pump subsystem 63, and a perforated core honeycomb panel subsystem 64.
11 The subsystem 64 includes a first facing sheet 66, a 12 second facing sheet 68, and a flexible perforated 13 honeycomb core 70. The core 70 is described in greater 14 detail in our U.S. Patent 5,180,619. The core 70 includes cell walls 71 with perforations 72 and is affixed to the inside 16 surfaces of the first facing sheet 66 and the second 17 facing sheet 68. The facing sheets extend outwardly 18 beyond the core 70 and are bonded together around their 19 perimeters as indicated at 74 so as to form an enclosed chamber 76 which is hermetically sealed and adapted to 21 contain a suitable gas. For purposes of illustration, the 22 chamber walls are broken away as indicated at 78.
23 In order to permit the gas contained within the 24 enclosed chamber 76 to be increased or decreased in volume or pressure, the pump subsystem 63 is communicatively 26 coupled to the chamber 76. The subsystem 63 includes a 27 bulb pump 80 that is coupled via a conduit 81 to the 28 chamber 76. An exhaust valve 82 is installed in the 29 conduit 81 and allows the chamber 76 to be vented to atmosphere. As will be appreciated by those skilled in 31 the art, the selected addition or subtraction of gas into 32 or out from the enclosed chamber 76 will result in a 33 change in the force-dissipating characteristics or shock 34 absorbing capabilities of the panel in response to applied forces such as illustrated by the arrow 83.
36 Honeycomb, and particularly anisotropic honeycomb has 37 a number of beneficial characteristics for anatomical 38 support applications in general, and particularly for 1 mattress and seating applications where the disadvantages 2 of more traditional materials, such as gels and foams, 3 become particularly unacceptable. Important 4 characteristics for general seating, and especially for .
wheelchair seating materials, include pressure relief 6 (load spreading), comfort, stability, durability, low 7 maintenance, light weight, and low transmissibility (good 8 impact isolation).
9 Pressure relief is particularly important for wheelchair seating applications because local pressure 11 spots, within the range of 60-80 mm Hg (1.16 - 1.55 psi), 12 quickly develop into sores on relatively immobile people.
13 Seat cushions having honeycomb panels of the present 14 invention are ideal for use as wheelchair cushions because such panels have relatively flat force deflection 16 characteristics. Fig. 7 shows a force-deflection plot 84 17 of a foam cushion compared to a force deflection plot 86 18 of a cushion having a honeycomb panel of the present 19 invention. The modulus (i.e. compressive force divided by deflection) over a 15 to 55 percent deflection range, for 21 foam is depicted by a line 88. The modulus, over the same 22 deflection range, for honeycomb of the present invention 23 is depicted by a line 89. The figure shows that the 24 modulus for the honeycomb panel cushion is approximately one-fourth that of the foam cushion. Pressure variations, 26 in the honeycomb panel cushion caused by anatomical 27 features (i.e protrusions) of the wheelchair user, are 28 approximately one-fourth those of foam cushions. Thus, a 29 wheelchair user's anatomical protrusions are less likely to cause local high pressure spots and bed sores if the 31 user sits on a honeycomb panel cushion of the present 32 invention rather than on a typical foam cushion.
33 The characteristic of honeycomb that makes it an 34 ideal in this area is the relatively flat "plateau region'°
that characterizes the honeycomb panel's force-deflection 36 property. In Fig. 8, a force-deflection relationship or 37 line 90 is plotted for honeycomb constructed in accordance 38 with the present invention. The force-deflection line 90 39 is measured over a useable deflection range 91 that ranges WO 95/00052. p PCT/US94/07129

-15-1 from 0 to nearly 80 percent deflection. It will be noted 2 from the figure that there are three distinct regions in 3 the force-deflection line. There are two regions where 4 the modulus (i.e. slope) of force over deflection is very steep, that is, the modulus one region 92 and the 6 boi~toming region 94. However, in the plateau modulus 7 region 93, which extends over the plateau region 8 deflection range 95 (i.e. roughly 8-75 percent 9 deflection), the slope of the line is relatively flat. If the honeycomb configuration is properly selected such that 11 the weight of the wheelchair user divided by his sitting 12 area places the user in the middle of the plateau modulus 13 region 93 then local increases or decreases in cushion 14 def lection caused by the user s anatomical features do not appreciably change the pressure exerted on the user. In

16 other words, the user s anatomical protrusions do not

17 create the local high pressure spots which could lead to

18 bedsores and other similar ulcerations. In engineering

19 terminology, the compressive modulus of honeycomb constructed in accordance with the present invention, is 21 less over the plateau region 93 than the compressive 22 modulus of typical foam or gel seat cushions.
23 Pressure relief by itself is not sufficient to make 24 a satisfactory wheelchair seating cushion because stability must also exist. The best pressure relief 26 system is ineffective if during maneuvers or motions the 27 user tips or slides off the seating area of the cushion.
28 Fig. 9 depicts the self-aligning and supporting 29 characteristic of honeycomb panels of the present invention. A user profile 96 is illustrated as being 31 disposed onto a seat cushion 97 constructed from a 32 honeycomb panel of the present invention. As depicted at 33 98, in response to the user load, the honeycomb cells tend 34 to align themselves in a buttressing manner with the applied load, even as the load shifts. This effect can be 36 enhanced by selecting a softer honeycomb for the topmost 37 layer of the cushion, in effect creating a buttressed 38 pocket for the lateral portions of the thighs and 39 buttocks. In addition, the anisotropic flexing WO 95/00052 ~ .PCT/1JS94/07129 1 characteristics of a single and double walled honeycomb 2 provide enhanced stability (i.e. greater shear modulus) in 3 the direction of the double walls. Depending on the needs 4 and activity level of the user, this orientation can be changed to provide the most effective support. For a 6 typical user (this would be support in the fore and aft 7 orientation to help prevent slumping or sliding off the 8 cushion.
9 Another principal benefit of the honeycomb cushion characterized by the present invention is the ability to 11 tailor it (e. g. varying materials, varying cell 12 configuration and size, etc.) to create the desired 13 cushioning and stabilizing characteristics. The honeycomb 14 panel may be tailored either by adding other components, e.g. fluids, or by not introducing elements such as 16 fluids, foam, or other elements which add costs and reduce 17 durability. As an example, one or more layers of the 18 honeycomb cushion can contain perforated cells walls, 19 which in effect creates a configuration that breathes like an open cell foam but without the foam's porosity and 21 resultant susceptibility to absorbing liquids. A
22 perforated cell honeycomb can provide performance benefits 23 such as quicker recovery from loading and a lower modulus 24 with greater displacement capability than the same configuration in enclosed cell honeycomb. In conjunction 26 with the inflation device and valve arrangement, as 27 illustrated in Fag. 6, the perforated cell cushion with 28 sealed edges can be pressurized to increase the air 29 cushion effect in situations where this is beneficial.
Note that a perforated honeycomb air cushion is much more 31 shear resistant, thus more stable, than an equivalent 32 conventional air cushion.
33 Compression set resistance and resistance to repeated 34 loadings, i.e. good material memory, are also important benefits of a seat cushion having honeycomb of the present 36 invention. The compressive resistance and recovery of 37 both honeycombs and foams comes from bending of the °'strut 38 elements" which comprise their geometries. These strut 39 elements are more uniform in honeycomb than foam. Because WO 95/0005a 1 of this greater uniformity, the compression set resistance 2 and recovery is greater in honeycomb than in foam. In 3 addition, closed cell (faced) honeycomb has the additional 4 resilience afforded by the integral trapped air creating an air spring. Comparison testing of honeycomb and foam 6 configurations used for seating applications in which 7 comparable samples were loaded daily for 16 hours on and 8 8 .hours off, revealed 1.5 to 2.0 percent compression set 9 for the foams compared to less than 1 percent for honeycombed seating cushions of the present invention.
11 Also, the honeycomb seating cushions of the present 12 invention are light weight and require low maintenance.
13 Weight is an important factor during transfer operations 14 of the wheelchair into and out of a vehicle. Low maintenance and ease of cleaning are important because a 16 wheelchair cushion cannot necessarily be quickly replaced 17 if incontinence or an accidental spill wets the cushion.
18 Honeycomb panels of the present invention typically have 19 solid facing sheets which act as washable barriers that will not absorb water like foam cushions. Nor are 21 honeycomb panels susceptible to puncturing like some of 22 the gel- filled cushions currently available.
23 Referring now to Fig. l0A through 10E wherein are 24 depicted cross sectional views of an improved cushion in accordance with the present invention. Fig. l0A depicts 26 ~ a single flexible honeycomb panel 100 encased within a 27 vinyl or similar covering 102. The panel 100 is 28 constructed in accordance with the referenced U. S. patents 29 and includes a non-perforated core 104, and facing sheets 103 and 105. Although a single unperforated cell wall 31 honeycomb panel is illustrated it will be appreciated that 32 in the alternative a single perforated core honeycomb 33 panel may be used as an alternative embodiment.
34 In an alternate embodiment not shown, the panel 100 could be removed from the covering 102 and either or both 36 of the facing sheets 103 and 105 perforated in a 37 predetermined pattern. The area of the perforations could 38 be varied depending on the specific requirements of the 39 user. For example, if a particular user needed greater 1 cushioning for a certain region of his body, the facing 2 sheets for the cushion area supporting this body region 3 could be perforated. In this manner, the cushion 4 apparatus can be individually customized to a user's specific needs. Perforating the cushion in a 6 predetermined manner to accommodate specific user 7 requirements can be utilized for any embodiment of the 8 present invention.
9 Referring to Fig. lOB which illustrates two perforated core honeycomb panels 104 and 106 encased 11 within the covering 102, it should be noted that honeycomb 12 panel 104 is of different size cell construction than 13 honeycomb panel 106, panel 106 having larger cell walls as 14 illustrated in the figure. Further, although an embodiment with two different honeycomb panels has been 16 illustrated it is possible to construct the cushion with 17 two equally sized honeycomb panels. Alternately, 18 different types of honeycomb panels may be mixed according 19 to the supporting properties desired. For example, panels having different core designs (i.e., cell size, 21 configuration, or materials) may be used. Also, a non-22 perforated cell wall honeycomb panel may be configured 23 with a perforated cell wall honeycomb panel and vice 24 versa. In addition, two or more layers of honeycomb panels may be stacked in accordance with the descriptions 26 referenced earlier in our prior U.S. patents.
27 Referring to Fig. lOC which depicts an improved 28 cushion having a pressurized honeycomb panel 110 encased 29 within the covering 102. As described earlier, the pressurized honeycomb panel 110 is comprised of a 31 perforated honeycomb core 112, encased within a non-32 perforated facing sheet covering 114, that is in 33 communication with a pump subsystem 116, via a conduit .
34 118. In this manner, the pressurized honeycomb panel 110 may be alternatingly pressurized to vary the support 36 characteristics of the honeycomb core 112 contained 37 within.
38 Referring to Fig. lOD which illustrates a multi-layer 39 cushion having a plurality of honeycomb panels contained WO 95/00052, PCT/US94/07129 1 within a covering 102. In this particular embodiment, the 2 pressurized honeycomb panel 110 is attached to a non-3 perforated core honeycomb panel 120. Alternately, two 4 pressurized honeycomb panels could be used with each panel system having different properties, i.e. different 6 materials and/or cell configurations and sizes. In 7 addition, each individual panel could have different 8 stiffnesses in different areas. For example, a stiffer 9 area would be placed in a forward area where the user's l0 leas and thighs are supported, and a softer area placed 11 beneath the buttocks area. This can be accomplished by 12 constructing the panels with more than one cell 13 configuration. In another embodiment not depicted in the 14 figure, the panel 120 could have perforated cells walls rather than non-perforated cell walls as illustrated.
16 Finally, although two honeycomb panels are depicted, more 17 than two panels could be employed, and the arrangement of 18 panels could have a pressurized panel disposed between 19 non-pressurized panels or a non-pressurized panel disposed between two pressurized panels.
21 Fig. l0E illustrates a multi-layer apparatus 164 22 having a two-layer panel subsystem 166 disposed onto a 23 pump subsystem 168. The panel subsystem 166 includes 24 pressurized honeycomb panels 170 and 172. Each panel has perforated cell walls 176, 178 and facing sheets 170a and 26 170b, 172a and 172b. Each facing sheet has a plurality of 27 perforations 176a and 176b, and 178a and 178b. The two 28 panels 170 and 172 are covered by a permeable covering 174 29 that permits the passage of fluid (e.g. air) from the panels 170 and 172. The pump subsystem 168 includes a 31 base plate 180 having a channel 182 formed therein so that 32 the channel can be communicatively coupled, via a conduit 33 168, to a pump or fan device 188. A plurality of exhaust 34 ports 184 are formed in a surface 181 of the base plate 180 and intersect with the channel 182. The pump device 36 188 is also communicatively coupled to a fluid source (not 37 shown) via an input conduit 189.
38 Fluid (e.g. air) is drawn from the fluid source, in 39 the direction indicated by the arrow 190, by the pump

-20-1 device 188. Fluid is passed through the conduit 186 into 2 the channel 182 and out through the ports 184 of the base 3 plate 180. The fluid passes through the contacting 4 permeable covering 174 and into the panel 172, via the perforations 178b in the facing sheet 172b. The fluid 6 passes from the panel 172 to the panel 170 via the 7 perforations 178, 178a, and 176b. Finally, the fluid 8 exits the panel 170, via the perforations 176 and 176a, 9 out through the permeable covering 174. The fluid exiting from the apparatus cools and comforts a user sitting 11 thereon.
12 It will be appreciated that only one panel or even 13 additional panels may be utilized to maximize the comfort 14 and support for a particular user. Also, a perforated covering may be used in lieu of the permeable covering 16 174. Further, the pump device 188 may draw from a variety 17 of fluid sources other than the ambient environment.
18 Although not illustrated, an alternate pump subsystem 19 may include a pump device communicatively coupled to a porous conduit. The conduit being similarly disposed as

21 the base plate 180 or, in the alternative, the conduit

22 could be disposed underneath the uppermost panel (e. g.

23 between panels 170 and 172) for supplying cooling air

24 through panel 172 to the user.
Fig. 11 illustrates a partially broken view of yet 26 another alternative embodiment of an improved cushion 122.
27 The cushion 122 includes a honeycomb core 126, facing 28 sheets 128 and 129, a foam pad 130, all encased within a 29 covering 124. As more clearly illustrated in Fig. 12, the honeycomb core 126 is disposed on top of the foam 130.
31 Although a non-perforated honeycomb core is illustrated, 32 a perforated cell wall honeycomb core could be utilized, 33 or alternatively a pressurized honeycomb panel system 34 could be utilized. Fig. 13 illustrates still another embodiment of the seat cushion 122 wherein a plurality of .
36 cavities 132 and 134 are disposed on the surface of the 37 seat cushion 122. Within each cavity a separate honeycomb 38 core insert 136 is placed. The particular inserts 39 illustrated in Fig. 13 are non-perforated cell wall WO 95100052 _, ,, PCT/I1S94/07129 1 honeycomb core inserts with top and bottom facing sheets 2 138, 140. In the alternative, the core inserts 136 could 3 be constructed from perforated cell wall honeycomb panels . 4 or pressurized honeycomb panels. Although only two core inserts have been illustrated in the figure, a plurality 6 of core inserts could be installed on numerous locations 7 on the surface of the cushion to vary the support 8 characteristics of the cushion to conform to the 9 individual needs of the wheelchair user. Thus, core inserts of varying stability and stiffness could be 11 interchanged to individually tailor the support and 12 pressure relief characteristics of the cushion. Although 13 not illustrated, in a multi-layer cushion apparatus, the 14 core inserts could be removable from any of the panels (i.e. in a three layer apparatus, the core insert could be 16 removable from the second panel).
17 A logical extension of the anatomical support cushion . 18 described above is a pad used for supporting the buttocks, 19 shoulders, head, and other parts of the anatomy of a reclining or sitting user. Fig. 14 is a perspective view 21 of a bed 142 supported on a standard hospital bed frame 22 144, the bed 142 having carrying straps 146 disposed at 23 numerous location around its periphery. The bed 142 of 24 the present invention is not limited to use in a hospital environment but may be used in other human care facilities 26 (e.g. nursing, convalescent, retirement homes, etc.) or 27 other environments.
28 Fig. 15 depicts an enlarged perspective view of the 29 bed 142 illustrated in Fig. 14, but with the carrying straps 146 omitted for clarity. The bed 142 includes a 31 mattress 150 with a mattress pad 148 dispose thereon and 32 which covers the entire mattress 150. It will be . 33 appreciated, however, that the mattress pad 148 could be 34 sized such that it covers only a portion or discrete portions of the mattress 150. As illustrated in the 36 cutaway portion, the mattress pad 148 includes a honeycomb 37 core panel 152 having a facing sheet 154 and a facing 38 sheet 160 (not shown). The honeycomb core panel 152 can 39 be configured in ways different than the type illustrated, 1 i.e. perforated cell walls, unfaced honeycomb core, etc.
2 Fig. 16 is a cross-sectional view taken along the 3 line 16-16 of Fig. 15, and depicts the construction of the 4 mattress pad 148 and mattress 150. The mattress 150 includes a foam core 152 encased within a mattress 6 covering 154. The mattress pad 148 includes the honeycomb 7 core panel 152, facing sheets 154 and 160, and a pad 8 covering 162 encasing the panel 152 and facing sheets 154 9 and 160.
Fig. 17 is a perspective view of a contoured seat 11 cushion 200 which is an alternate embodiment of the seat 12 cushion 12 depicted in Fig. 1. Seat cushions, fabricated 13 from at least one panel of flexible thermoplastic 14 elastomeric honeycomb and having a planar or non-contoured surface engagable with a body surface (e. g., thighs, 16 buttocks) of a user, provide pressure relief, stability, 17 durability and washability. However, a planar engagable 18 surface does not provide as much positioning and posture 19 control of the user as does a non-planar or contoured engagable surface.
21 The contoured seat cushion 200 includes an upper 22 layer 206, an intermediate layer 208, and a bottom layer 23 210. Each layer is fabricated from thermoplastic 24 elastomeric honeycomb in the manner described above, and the construction of each of the cells of the honeycomb 26 panels of the layers is also as described above. Each 27 cell wall of each layer has an upper extremity and a lower 28 extremity (best seen in Fig. 18-21). The intermediate 29 layer 208 is sandwiched between the layers 206 and 210 and is attached to the lower extremity 252 and the upper 31 extremity 258 of the upper layer 206 and the bottom layer 32 210, respectively.
33 In addition, a surface 205 formed by the upper 34 extremities 250 of the cell walls of the upper layer 206 has been sculpted or shaped to provide the distinctive -36 illustrated contoured features depicted in Fig. 17. The 37 directional terminology adapted for the cushion 200 is 38 also illustrated in Fig. 17. A direction 201 is WO 95/00052 " PCT/US94/07129 1 designated as "left", a direction 202 is "right", 2 direction 203 is "rear", and a direction 204 is '°front".
3 A central rear portion of the surface 205 of the 4 cushion 200 has been formed with a coccyx cutout depression region 212 which prevents pressure buildup on 6 a sensitive coccyx (i.e. tailbone) which cannot take as 7 much pressure as other areas of the user's body. An 8 ischial dishing depression region 214 is formed forward of 9 the cutout region 212. The ischials are a pair of bones forming the dorso-posterior portion of the pelvis; the 11 interior part of the human pelvis upon which the body 12 rests during sitting. A trochanter shelf is a slightly 13 concave region formed in the surface 205. One shelf is 14 disposed to the left (shelf region 218) and one shelf is disposed to the right (shelf region 216) of the ischial 16 dishing region 214. The trochanter is a projection on the 17 proximal end of the femur.
18 An adductor shelf region 228 is an upwardly curved 19 region formed on the surface 205 and is disposed along the center line of the seat cushion 200 and spaced generally 21 equidistant from the left and the right edges of the 22 cushion 200. A left abductor region 220 is an upwardly 23 curved region formed on the surface 205 and disposed to 24 the left of the region 228. Similarly, a right abductor region 222 is formed on the surface 205 to the right of 26 the region 228. Leg troughs 224, 226 are formed on the 27 surface 205 and flank the region 228 on the left and the 28 right sides, respectively. Posturing or positioning 29 prablems include abduction or adduction of the legs (the legs are either too far apart or too close together).
31 The ischial dishing region 214, the abductor regions 32 220, 222, and the adductor region 228 perform positioning 33 or posture control of a user of the contoured wheelchair 34 seat cushion 200. The abductors and adductors are essentially side bolsters and a pommel, respectively, 36 designed to prevent the user's legs from sliding around 37 and prevent the user's knees from banging together. The 38 dishing region 214 allows the ischials of the user to 39 engage the surface 205 of the cushion 200 without 1 restriction and sink into a natural, anatomic position 2 thereby alleviating the tendency for posterior tilt, or 3 slouching of the pelvis. The rear dishing in the back is 4 designed to evenly support the user's pelvis so that it remains upright and straight. This provides a stable 6 foundation and a greater balance for the user who has 7 limited or no use of his lower truck muscles.
8 The ischial dishing region 214 and the abductor 9 regions 220, 222 and adductor region 228 also provide for increased stability for the user of the seat cushion. As 11 described above, seat stability is particularly critical 12 for wheelchair users. A cushion which provides a stable 13 seating platform enhances the user's ability to wheel and 14 turn the wheelchair by grasping the wheels, to get in and out of the chair, and to perform other dynamic movements.
16 A cushion which provokes non-stability or a fear of 17 falling from the chair will inhibit the user's range of 18 movement. Thus, the dishing region 214 and the adductor 19 region 228 and abductor regions 220, 222 provide the lateral support that is needed for the user under dynamic 21 conditions.
22 As described above, the nature of a thermoplastic 23 elastomeric flexible honeycomb panel is that it enhances 24 the pressure relief capability of the cushion. This pressure relief capability is further enhanced by 26 contouring or shaping the surface 205 that is engageable 27 with the body surface of the wheelchair user. For 28 example, the ischial dishing region 214 increases the 29 contact area with the buttocks and upper thighs of the user. Since the user's weight is distributed over a 31 larger area, the cushion material undergoes less 32 deflection to conform to the body, therefore, the 33 resistive force is less. This translates into reduced 34 pressures over a wider contact area. The coccyx cutout region 212 prevents pressure build up on the sensitive 36 tailbone which cannot take as much pressure as other 37 areas. Also, the shelf regions 216, 218 cradle the 38 trochanters (the bony protuberances extending from the 39 upper part of the femur) for added support which relieves WO 95/00057 '~ . PCT/LTS94107129

-25-1 pressure from the ischials. Further, the shaped leg 2 troughs 224, 226 increase the contact area with the user's 3 thighs thereby distributing the user's weight over a 4 larger area and more evenly distributing the pressure on the cushion.
6 In addition, using an elastomeric flexible material 7 avoids hammocking. Hammocking is defined as a suspension 8 of the bony prominences of the user on the surface of the 9 cushion preventing total conformation of the cushion to the user's body, thereby preventing complete pressure 11 equalization. Using an elastomeric material allows the 12 upper or contact surface 205 of the cushion to stretch in 13 response to pressure from the bony prominences of the 14 user, thereby distributing the pressure over a larger area.
16 Also, the wheelchair cushion 200 is extremely 17 durable. Because of the existing contour, the material in 18 the cushion experiences less compressive deflection and 19 fatigue, while remaining resilient longer.
However, it should be noted that the cells of the 21 honeycomb panel of the cushion 200 could be oriented as 22 shown by the cells in the region 230 or as shown by the 23 cells in the region 240. That is, the double wall 24 portions 234 of the cells in the region 234 may be aligned in the front-rear direction. Alternately, the double wall

26 portions 244 of the cells in the region 240 may be aligned

27 in the left - right direction. In either case, the walls

28 241 or 231 of each of the cells are perforated with

29 perforations 241, 242 or 232. Perforating the cell walls of the cells of each of the layers 206, 208, 210 enables 31 the seat cushion 200 to be lightweight and washable, and 32 also permits cooling air to pass beneath the user thereby 33 providing a comfortable seating surface. In addition, the 34 open or bare faced honeycomb layers allow moisture to drain through the cushion thereby keeping the uppermost 36 layer 206, i.e. the layer engagable with the skin of the 37 user, dry.
38 Fig. 18 is a partial sectional view of a contoured 39 seat cushion 201 having a generally similar construction 1 to the cushion 200 (Fig. 17). The cushion 201 includes 2 the upper layer 206 having an upper extremity 250 and a 3 lower extremity 252. A contoured or non-planar surface is 4 formed by the upper extremity 250 of the cells of the upper layer 206. In contrast, the upper extremity 254 and 6 the lower extremity 252 of the intermediate layer 208 is 7 planar. Similarly, the upper extremity 258 and the lower 8 extremity 260 of the bottom layer is planar. The figure, 9 the upper extremity 254 of the layer 208 is attached to the lower extremity 252 of the upper layer 206.
11 Similarly, the upper extremity 258 of the bottom layer 210 12 is attached to the lower extremity 254 of the intermediate 13 layer 208. The three layers 206, 208, 210 are encased 14 within, but not bonded or attached to, a stretchable, breathable and permeable casing 209, thereby permitting 16 the attached layers 206, 208, 210 to be removed and washed 17 and cleaned apart from the casing 209. The casing 209 may 18 be formed with vents (not shown) to enhance its 19 breathability and permeability. It should be noted that wetness or moisture (from user incontinence or otherwise) 21 drains through the cushion, via the unfaced layers 206, 22 208, 210, and the permeable casing 209, to keep moisture 23 away from the user's skin.
24 Fig. 19 is a partial sectional view of a contoured seat cushion 203, which is generally similar to cushion 26 200 (Fig. 17) The upper extremity 254 of the intermediate 27 layer 208 forms a non-planer or contoured surface. The 28 upper extremity 254 is attached to the lower extremity 252 29 of the upper layer 206 thereby causing the upper extremity 250 of the upper layer 206 to be disposed in a non-planer 31 or contoured manner. Thus, a body portion of the user 32 will engage a contoured or non-planer surface. It will be 33 appreciated, that the bottom layer 210 could have a 34 contoured upper extremity 258 in addition to or in lieu of the extremity 254. Alternately, the lower extremities of 36 either the intermediate layer 208 or the bottom Layer 210 37 could be contoured thereby causing the upper extremity 250 38 of the upper layer 206 to be non-planar.

WO 95/00052, 1 Fig. 20 is another embodiment 207 of the contoured 2 seat cushion illustrated in Fig. 17. In this embodiment 3 three bolstering or reinforcing regions 264, 266, and 268 4 are formed in the intermediate layer 208. In the regions 264, 266, 268, as compared to the other portions of the . 6 cushion 207, the cell size may be reduced, or the 7 thermoplastic material comprising the cell walls may be 8 made from a stiffer material (e.g. higher durometer) or, 9 the cell walls may be constructed from ribbons having greater thickness. The effect is to provide a stiffer 11 region for supporting the upper layer 206. In this 12 manner, for example, if the regions between the 13 reinforcing regions were constructed of a less stiff or 14 more flexible material, then the user and his bony prominences would sink between the reinforcing regions 16 which would perform the same functions as a upwardly 17 contoured bolster 220, 222 or other similar device. Also, 18 the cells in the bolster regions are less prone to 19 collapse or roll over as the user leans to one side. It will be appreciated as an alternate to the illustrated 21 embodiment, the reinforcing regions could be placed in 22 either the upper or the bottom layers.
23 Fig. 21. is a sectional view of yet another embodiment 24 of the contoured seat cushion in Fig. 17. In this embodiment, a thermoplastic elastomeric facing sheet is 26 disposed between the upper and the intermediate layers 27 206, 208. The facing sheet 270 is formed with a plurality 28 of perforations 272 to allow air and fluid to flow from 29 one layer to the other. For example, cooling air can flow from the bottom layer to the upper layer and ultimately to 31 the user. It will be appreciated, that the facing sheet 32 could be disposed between the intermediate and the lower 33 layers.
34 It will also be appreciated that the cell walls of any of the layers of any of the embodiments 201, 203, 207 36 could be unperforated.
37 Although preferred, and alternate embodiments of the 38 present invention have been disclosed above, it will be 39 appreciated that numerous alterations and modifications 1 thereof will no doubt become apparent to those skilled in 2 the art after having read the above disclosures. For 3 example, the anatomical support cushions may be configured 4 in any appropriate shape, with multiple panels and with various combinations of perforated and non-perforated core 6 panels, and with core walls and/or face sheet perforations .
7 the number and/or hole size of which are tailored to 8 achieve desired damping characteristics. It is therefore 9 intended that the following claims may be interpreted as covering all such alterations and modif ications as fall 11 within the true spirit and scope of the invention.

Claims (18)

CLAIMS:

1. In an anatomical support apparatus having a frame for supporting said apparatus, an outer envelope, and a resilient inner body encased within said envelope, both said inner body and said envelope being supported by said frame, an improved resilient inner body, comprising:
a first panel including a first honeycomb core formed of undulated strips of resilient thermoplastic material, thermal compression bonded together to form cell walls defining a plurality of contiguous regularly shaped cells, the opposite extremities of said cell walls forming first and second core faces on opposite sides of said first core, at least some of said cell walls having perforations therein; and means tending to said first core in its expanded cellular configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user of said apparatus and including a first facing sheet bonded to said first face and a second facing sheet bonded to said second face, said first facing sheet and said second facing sheet of said first panel being sealingly joined together about the perimeter of said core to provide a chamber enveloping said first core; and means fluid-communicatively coupled to said first panel for selectively adding fluid to or subtracting fluid from said chamber, said fluid flowing into said cells and through the perforations of said walls to change certain characteristics of said first panel.

2. In an anatomical support apparatus, an improved resilient inner body as recited in claim 1, wherein said means tending to maintain includes:
a planarizing thermal compression deformation of said first face of said first core formed by upper extremities of said cell walls.

3. An improved resilient inner body as recited in claim 2, wherein said means tending to maintain includes:
a planarizing thermal compression deformation of said second face of said first core formed by lower extremities of said cell walls.

4. In ananatomical support apparatus, an improved resilient inner body as recited in claim 1, further including:
at least one other panel affixed to said first panel and including a second honeycomb core formed of undulated strips of resilient thermoplastic material, thermal compression bonded together to form cell walls defining a plurality of contiguous regularly shaped cells; and means for maintaining said second core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user of said apparatus.

An improved seat cushion comprising:
a first panel including a honeycomb core formed of resilient thermoplastic and including cell walls defining a plurality of contiguous regularly shaped cells, at least some of said cell walls of said first panel having perforations therein, the extremities of said cell walls defining first and second core faces;
means for maintaining said core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user of said apparatus, and including a first facing sheet of said resilient material bonded to said first core face and a second facing sheet of said resilient material bonded to said second core face, said first and second facing sheets of said first panel being sealingly jointed together about the perimeter of said core to provide a chamber; and mean fluid-communicatively coupled to said first panel for selectively adding fluid to or subtracting fluid from said chamber, said fluid flowing through the perforations of said walls to change certain characteristics of said first panel.

6. An improved seat cushion as recited in claim 5 further including:
at least one other panel affixed to said first panel and including a second honeycomb core formed of resilient thermoplastic material and including cell walls defining a plurality of contiguous regularly shaped cells;
means for maintaining said second core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user.

7. An improved mattress pad comprising:
a first panel including a first honeycomb core formed of resilient thermoplastic material and including cell walls defining a plurality of contiguous regularly shaped cells, the opposite extremities of which form first and second core faces on opposite sides of said first core, at least some of said cell walls of said first panel have perforations therein;
means tending to maintain said first core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user, and including a first facing sheet bonded to said first face and a second facing sheet bonded to said second face, said first facing sheet and said second facing sheet of said first panel being sealingly joined together about the perimeter of said core to provide a sealed chamber envelope said first core;
and means fluid-communicatively coupled to said first panel for selectively adding fluid to or subtracting fluid from said sealed chamber, said fluid flowing into said cells and through the perforations of said walls to change certain characteristics of said first panel.

8. An improved mattress pad as recited in claim 7 and further including:
at least one other panel affixed to said first panel, including a second honeycomb core formed of resilient thermoplastic material and including cell walls defining a plurality of contiguous regularly shaped cells;
means tending to maintain said second core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user.

9. In an anatomical support apparatus having a supporting frame, a perforated outer envelope, and a resilient inner body encased within said envelope, both said inner body and said envelope being supported by said frame, an improved resilient inner body, comprising:
a first panel including a first honeycomb core formed of resilient thermoplastic material and including cell walls defining a plurality of contiguous regularly shaped cells, the opposite extremities of said cell walls forming first and second core faces on opposite sides of said first core; and means tending to maintain said first core in its expanded cellular configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user of said apparatus, and including at least a first facing sheet bonded to said first face and a second facing sheet of material bonded to said second face, said first facing sheet and said second facing sheet of said first panel being perforated and joined together about the perimeter of said core to provide a chamber enveloping said first core; and means fluid-communicatively coupled to said first panel for adding fluid to said chamber, said fluid flowing through said perforations of said walls and at least one of said first and second facing sheets.

10. In an anatomical apparatus, an improved resilient inner body as recited in claim 9, further including:
at least one other panel affixed to said first panel and including a second honeycomb core formed of undulated strips of resilient thermoplastic material, thermal compression bonded together to form cell walls defining a plurality of contiguous regularly shaped cells; and means for maintaining said second core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user of said apparatus.

11. An improved seat cushion comprising:
a first panel including a honeycomb core formed of resilient thermoplastic material and including cell walls defining a plurality of contiguous, regularly shaped cells, at least some of said cell walls panel having perforations therein, the extremities of said cell walls defining first and second core faces;
means for maintaining said core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user, and including a perforated first facing sheet of said resilient thermoplastic material bonded to said first core face and a second facing sheet of said resilient thermoplastic material bonded to said second core face, said first and second facing sheets being sealingly joined together about the perimeter of said core to provide a chamber; and means fluid-communicatively coupled to said first panel for adding fluid to said chamber, said fluid flowing through said perforations of said walls and said first facing sheet.

12. An improvise seat cushion as recited in claim 11, and further comprising an outer envelope that is perforated, and wherein said first facing sheet and said second facing sheet of said first panel are perforated and are joined together about the perimeter of said first core.

13. An improved seat cushion as recited in claim 12, and further including:
at least one other panel affixed to said first panel and including another honeycomb core formed of resilient thermoplastic material and including cell walls defining a plurality of contiguous regularly shaped cells;
and means tending to maintain said core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user.

14. An improved mattress pad comprising:
a first panel including a first honeycomb core formed of undulated strips of resilient thermoplastic material, thermal compression bonded together to form cell walls defining a plurality of contiguous regularly shaped cells, the opposite extremities of which form first and second core faces on opposite sides of said first core, at least some of said cells of said first panel have perforations therein;
means tending to maintain said first core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user, and including a first facing sheet bonded to said first face and a second facing sheet bonded to said second face, at least one of said first and second facing sheets being perforated, said first facing sheet and said second facing sheet of said first panel being joined together about the perimeter of said core to provide a chamber enveloping said first core; and means fluid-communicatively coupled to said first panel for adding fluid to said chamber, said fluid flowing through said perforations of said walls are at least one of said first and second facing sheets.

15. An improved mattress pad as recited in claim 14 and further including:
at least one other panel affixed to said first panel and including a second honeycomb core formed of undulated strips of resilient thermoplastic material, thermal compression bonded together to form cell walls defining a plurality of contiguous regularly shaped cells; and means tending to maintain said second core in its expanded.
configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user.

16. An improved seat cushion, comprising:
(a) at least one contoured substrate including i) a first honeycomb core formed of resilient thermoplastic material and including cell walls defining a plurality of contiguous regularly shaped cells, at least some of said cell walls of said contoured substrate having perforations therein, the extremities of said cell walls defining first and second core faces, at least one of said extremities forming a contoured surface; and ii) means for maintaining said first honeycomb core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user of said cushion, and including a first facing sheet of said resilient material bonded to said first core face and a second facing sheet of said resilient material bonded to said second core face, said first and second facing sheets of said contoured substrate being sealingly joined together about the perimeter of said core to provide a first chamber;
(b) at least one planar substrate attached to one of said extremities of said first honeycomb core, said planar substrate having (i) a second honeycomb core formed of resilient thermoplastic material and including cell walls defining a plurality of contiguous regularly shaped cells, at least some of said cell walls of said planar substrate having perforations therein, the extremities of said cell walls defining third and fourth core faces, each of said extremities forming a planar surface; and ii) means for maintaining said second honeycomb core in its expanded configuration so that it will anisotropically flex to stabilize and spread any load applied thereto by a user of said cushion, and including a third facing sheet of said resilient material bonded to said third core face and a fourth facing sheet of said resilient material bonded to said fourth core face, said third and fourth facing sheets of said planar substrate being sealingly joined together about the perimeter of said core to provide a second chamber; and (c) means fluid-communicatively coupled to said contoured surface for selectively adding fluid to or subtracting fluid from said first chamber, said fluid flowing into said cells and through the perforations of said walls to change certain characteristics of said contoured surface, and means fluid-communicatively coupled to said planar surface for selectively adding fluid to or subtracting fluid from said second chamber, said fluid flowing into said cells and through the perforations of said walls to change certain characteristics of said planar surface.
whereby predetermined prominences of said user's body are received in said contours formed in said contoured surface.

17. An improved seat cushion as recited in claim 16, wherein said means for maintaining of each said first and said second honeycomb cores includes:
(a) a planarizing thermal compression deformation of a first face of said core formed by an upper extremity of said cell walls.

18. An improved seat cushion as recited in claim 17, wherein said means for maintaining of each said first and said second honeycomb cores includes:

(a) a planarizing thermal compression deformation of a second face of said core formed by a lower extremity of said cell walls.