US20100281619A1

US20100281619A1 - Air mattress system with inflatable limb chamber

Info

Publication number: US20100281619A1
Application number: US12/437,987
Authority: US
Inventors: David B. Beck; Jules A. deGreef; Corey Welch
Original assignee: R AND D PRODUCTS LLC
Current assignee: R AND D PRODUCTS LLC
Priority date: 2009-05-08
Filing date: 2009-05-08
Publication date: 2010-11-11

Abstract

A system and method for controlling the flow of fluid for an inflatable mattress having multiple, non-interconnected inflatable chambers and a moveable inflatable limb elevation chamber. Each inflatable chamber can be selectively inflated and deflated to vary the pressure exerted from the mattress surface to selected areas of a human body, thereby preventing the formation of decubitus ulcers. The limb elevation chamber may also be selectively inflated and deflated as well being positioned at any desired portion of the inflatable mattress in order to raise one or more human limbs off the surface of the mattress.

Description

BACKGROUND OF THE INVENTION

1. The Field of the Invention
The present invention relates generally to inflatable mattress systems and, more specifically, to an inflatable mattress system having a limb elevation chamber for positioning on a mattress having multiple, fluidly unconnected chambers that are selectively inflatable and deflatable.
2. The Relevant Technology
There is a belief that pressure sores or bedsore may develop when a bed-ridden person does not move for extended periods of time. That is, immobile people (e.g., unconscious, comatose, paralyzed, or in a some other form of vegetative state) typically do not move or are unable to move for extended periods of time (e.g., days, weeks). Immobile people who are bed ridden may remain essentially in the same location on the bed fostering the development of bedsores.
Bedsores are visually disfiguring, are generally regarded as painful, and are typically debilitating. In some cases they are believed to lead to other maladies or medical complications, including bone and blood infections and infectious arthritis. Bedsores can lead to the development of penetrating holes below the sore that burrow into bone. Bedsores are believed to lead to scar carcinoma, a form of cancer that develops in scar tissue. To reduce the incidence of bedsores in, for example, rest homes, attending staff are typically charged with the task of moving immobile people. That is, the immobile people are rolled on their beds from time to time for the purpose of a varying or changing the parts of the body of the immobile persons that are in contact with the support surface to reduce the risk of developing bedsores. Typically, moving immobile people is difficult because the immobile person is not able to assist. In turn, it is believed that the attending staff from time to time suffer injury (e.g., pulled muscles, hernia) associated with the task of moving the immobile people. Bedsores are a risk for people/patients in hospitals, nursing homes, and even in their own home when involved with a home health care treatment protocol under home care.
It is presently understood that bedsores generally form at points of pressure, where the weight of the patient's body presses the skin against the firm surface of the bed. The skin's blood supply is believed to be interrupted or reduced by the pressure in turn causing injury to skin cells. Unless the pressure is periodically relieved to allow full blood flow to the pressed areas of the skin, the skin cells in the area may develop ulcerations. The ulcerations can grow into notable bedsores some in excess of the area of a quarter or half dollar.
Inflatable mattresses have been proposed for use by or with immobile people. Many in the past are believed to be difficult to operate, expensive, and unreliable. An inflatable mattress that varies the pressure in separate cells under different parts of the body and that accurately and promptly operates to maintain the pressure and then vary it in accordance with individual or preprogrammed instructions is disclosed in U.S. Pat. No. 7,219,380 B2 (Beck). However, it is believed that use of the inflatable bed disclosed by Beck does not fully resolve the incidence of bedsores in the limbs including particularly the legs.
To reduce the incidence of bedsores, various limb elevation products (like pillows) have been used to reduce the incidence of bedsores. However, nothing in the art is known to cause the limbs—e.g., ankles, arms and lower legs—to be periodically raised and lowered relative to the surface of a support surface including the surface of an inflatable mattress.

BRIEF SUMMARY OF THE INVENTION

An inflatable mattress system includes a plurality of inflatable chambers assembled to define a support surface to support an occupant having at least one limb (e.g., arm or leg). Each of the inflatable chambers has at least one wall member forming an interior volume. It may also have multiple wall members. That is, each inflatable chamber may be in the shape of a cube or parallelepiped and in turn will have 6 sides. It may share a common side or wall with its adjacent inflatable chamber. Each wall member is made from a flexible material (e.g., plastic) selected to retain fluid. Each of the plurality of inflatable chambers has a chamber connector for fluid communication with the interior of the chamber. At least one wall member of each inflatable chamber is deflectable between a first inflated position and a second inflated position different from said first inflated position. That is, each chamber may be inflated to a selected level of inflation. Upon placement of a user or immobile person to the mattress, at least some of the chambers will deflect from the first inflated position to a second inflated position.
A plurality of deflectable resistors are attached to each of the inflatable chambers and preferably to a deflectable wall member of each chamber. Each of the deflectable resistors predictably varies its electrical resistance upon deflection from a first configuration to a second configuration. Each of the plurality of deflectable resistors deflects between its first configuration and its second configuration upon movement of said its wall member between its first inflated position and its second inflated position to generate a deflection signal upon application of electrical power to said deflectable resistors. The deflection of the resistors is thus reflective of said inflatable chamber movement.
The inflatable mattress system preferably includes an inflatable limb elevation chamber configured for positioning on said support surface to support a limb of the occupant or user such as an immobile person. The inflatable limb elevation chamber includes at least one elevation chamber wall member defining an elevation chamber interior volume. The elevation chamber wall member is made from a suitable flexible material selected to retain fluid. The elevation chamber wall member is deflectable between a first inflated elevation chamber position and a second inflated elevation chamber position different from the first inflated elevation chamber position. In effect, the occupant's limb or limbs are positioned on the limb elevation chamber causing the wall member to move or to depress. The elevation chamber has an elevation chamber connector positioned through the elevation chamber wall member for fluid communication between a source of fluid and the elevation chamber interior volume.
A fluid source is provided for supplying a fluid under pressure into each interior volume of the plurality of inflatable chambers and into said elevation chamber interior volume. The fluid source may be a source of compressed air that is readily available or a suitable pump or compressor provided to supply the compressed air. A first conduit means is connected to each of the chamber connectors and to elevation chamber connector for communicating fluid to and from the interior volume and the elevation chamber interior volume. A second conduit means is connected to a fluid source for communicating fluid to and from said fluid source.
The inflatable mattress system all has a discharge means for communicating fluid away from the interior volume of each inflatable chamber and the elevation chamber interior volume. A valve is connected to the first conduit means, the second conduit means and the discharge means. The valve is operable between a first position in which the valve places the first conduit means in communication with the second conduit means for supplying fluid from the fluid source to the interior volume of the inflatable chambers and the elevation chamber interior volume and a second position in which the valve places the first conduit means in fluid communication with the discharge means.
The inflatable mattress system also includes a controller connected to each of the plurality of deflectable resistors for supplying an electrical signal thereto and for receiving a deflection signal therefrom. The controller is preferably a microprocessor or equivalent and is configured to generate operating commands for operating the valve between its first position and its second position. The controller is connected to the valve which is of the type that it is electrically controllable (e.g., motor driven, solenoid) to supply said operating commands to the valve to cause it to move between its positions.
In preferred or alternate configurations, the limb elevation chamber is removable from the support surface. The controller includes a processor having a set of instructions for receiving the deflection signals and deriving an amount of desired inflatable chamber movement and for calculating the desired fluid pressure for specific inflatable chambers and then generating a signal for placing the valve in its first position and its second position.
In alternate configurations, the inflatable limb elevation chamber may have a plurality of chambers each separate from the other. Each chamber has a deflectable resistor attached to its respective elevation chamber wall member to operate as the other deflectable resistors.
The inflatable limb elevation chamber may be in multiple geometric shapes but is preferably in the shape of half a cylinder. The limb elevation chamber also preferably has means for attaching or for securing said elevation chamber to said support surface and more particularly the mattress. The securing means is desirably a hook and pile fastener arrangement. Alternately, the limb elevation chamber may extend substantially the width of the support surface with straps extending from opposite ends which may be sized to extend under the support surface to be held by the weight of the occupant on the support surface.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only presently preferred embodiments of the invention and are therefore not to be considered limiting of the scope of the claims presented herein. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 depicts in perspective a hospital bed having an inflatable mattress system positioned thereon with an inflatable limb chamber of the present invention;

FIG. 2 is an exploded perspective view with a cut away surface of one form of inflatable mattress of the invention;

FIG. 2A is a partial side view of an alternate arrangement of inflatable chambers useful in an inflatable mattress system of the present invention;

FIG. 3A shows in perspective an alternate arrangement of an inflatable mattress of the invention using several different sized inflatable chambers;

FIG. 3B is a perspective view of a limb elevation chamber of the present invention;

FIG. 4 is a front view of an alternate limb inflatable chamber of an inflatable mattress of the invention;

FIG. 5 illustrates a bottom view of the limb inflatable chamber of FIG. 4;

FIG. 6 is a top view of the limb inflatable chamber of FIG. 4;

FIGS. 7A and 7B are block diagrams illustrating the electrical and mechanical elements of the inflatable mattress system and limb elevation chamber of the present invention; and

FIG. 8 is an exploded perspective view of an alternate form of a mattress for use in the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments to illustrate and describe the features of the present inventions. The various exemplary embodiments have an air mattress system 11 which can be used with a conventional spring mattress, a separate base or support or positioned on a frame of a medical bed. The system 11 includes a mattress of the type having multiple, separate or isolated chambers that can be selectively inflated and deflated to increase and decrease the pressure exerted from various points of the mattress surface on a human body 10 having a torso 10A and lower extremities 10B and 10C when positioned on the mattress. A separate inflatable chamber 25 is now provided. It is inflated and deflated to raise and lower the limbs or extremities 10B and 10C of a person 10 on the mattress 20.
Referring to FIG. 1, an inflatable mattress system 11 includes a hospital bed 12 having a typical hospital bed frame 15 with an inflatable mattress 20 positioned on and supported by the bed frame 15. The inflatable mattress system 11 includes the inflatable mattress 20 plus related components for inflating and deflating the mattress 20 such as a separate chassis 19 that includes suitable controls 14 to operate the inflatable mattress 20 plus a source 13 of air under pressure (e.g., a compressor or an available hospital source) and suitable valves not illustrated to effect inflation and deflation of the chambers in the mattress 20 (as discussed hereinafter) and a separate limb elevation chamber 25 through suitable tube bundle 17 as desired.
It should be noted that the air has been stated to be the material or fluid used to inflate the chambers 50A-E (FIG. 2) of the inflatable mattress 20 as well as the limb elevation chamber 25. Of course other suitable fluids can be used including nitrogen gas or any other suitable and available gas. Inert gases such as argon may also be used. Various liquids may also be used, but are less desirable because a leak can be more difficult to deal with than the leak of a gas and in particular a harmless gas. Room air or compressed air is presently preferred as the desired fluid because it is available and inexpensive. Compressed and filtered air and nitrogen is sometimes available in a hospital setting. If the air or other gas is not dehydrated, the chassis may include one or more dehydrating devices for any gas that may be used including air. A drying tower with desiccant is presently contemplated to dry the air.
In the embodiment of FIG. 1, the inflatable mattress 20 is shown positioned on the hospital bed frame 15. Of course, those skilled in the art will recognize the inflatable mattress 20 may be positioned on or used with any suitable support structure including conventional bed frames, inner spring arrangements or structures, and various coil or leaf spring structures. Indeed, it may be positioned on a flat board or otherwise positioned on any structure of sufficient strength to support the inflatable mattress 20 with a user 10 positioned thereon with a suitable safety margin to accommodate visitors who may sit on the bed 12.
In FIG. 1, the hospital bed frame 15 is shown to include an undercarriage 16A, a foot board 16B, and various hand rails 18A, 18B, 18C and 18D. The hand rails 18A-D are all typically operable or movable between a stored position such as shown for hand rail 18C and a raised position such as seen for hand rails 18A, 18B and 18D. In the raised position, the handrails 18A, 18B, 18C and 18D function to retain a person on the mattress 20. The hospital bed 12, and more specifically the inflatable mattress 20 as here shown, is configured with an upper portion 20A, a middle portion 20B, and a lower portion 20C. The hospital bed 12 has means (e.g., an electric motor connected to a suitable gearing arrangements) positioned in a housing 16C which is operable to raise and lower at least the upper portion 20A relative to the lower portion 20C so that an occupant 10 can achieve different orientations of the occupant's body. For example, FIG. 1 shows the upper portion 20A positioned at an angle 22 relative to the flat axis 21 which is essentially or effectively horizontal to show that the upper portion 20A can be raised to elevate or raise the occupant's torso 10A above the flat axis 21 and in turn above the lower extremities 10B and 10C of the occupant 10 oriented over the lower portion 20C.
The lower portion 20C typically has means associated with it so that it also may be elevated relative to the flat axis or horizontal 21 in a manner similar to the upper portion 20A. However, it may also be rigid. No matter how the lower portion 20C is oriented, the lower extremities 10B and 10C would remain in contact with the support surface 20D for occupants who are incapable of moving their extremities thereby increasing the risk of bedsores if required to remain in or on the bed 12 for extended periods of time.
In FIG. 1, a separate limb chamber 25 is positioned on the support surface 20D by any suitable means. It may be simply positioned by someone under the limbs 10B and 10C of an occupant 10. An alternate chamber 25A is shown positioned proximate the ankles to elevate the lower limbs 10B and 10C a suitable distance 23 (e.g., about 2 to about 4 inches) so they are spaced away from the support surface 20D. In turn, air can pass under and about the extremities 10B and 10C to reduce the risk of bedsores. The limb chamber 25 or 25A also may be removably or fixedly attached to the support surface 20D by any means desired including, various configurations of snaps, Velcro® hook and pile fasteners, glue or even by plastic welding. While the limb chamber 25 may be attached to the support surface 20D, typical bed sheets may not comfortably fit over it. Thus in some applications it will be preferred to have the limb chamber 25 or 25A unattached so that attending personnel can position the inflatable support 25 on top of the typical sheet (or similar bed covering) placed over and/or on the support surface 20D in a desired location. When not attached, the limb chamber 25 and chamber 25A may have a tube 28 and 28A respectively connected for transmitting or communicating air or fluid in and out for inflation and deflation. The tubes 28 and 28A are preferably run under the inflatable mattress 20 for incorporation into the bundle of tubes 17 extending from the mattress 20 to the chassis 19. If the limb chamber 25 is attached to the support surface 20D, the tube 28 may extend through the mattress 20 or be secured tightly to the exterior of the mattress 20 (not shown).
The inflatable chamber 25 is here shown to have a width 26 which is shown to be less than the width 27 of the support surface 20D. The width 26 is any width suitable to extend under both limbs 10B and 10C of an occupant 10 or user when the limbs 10B and 10C are positioned generally in alignment as shown in FIG. 1. It is contemplated that in preferred embodiments, the width 26 will be at least half the width 27 of the support surface 20D and preferably about two thirds to three fourths the width 27 of the support surface 20D. The inflatable chamber 25 may even extend the full width 27 of the support surface 20D.
Referring now to FIG. 2, the inflatable mattress 20 is illustrated having a chamber portion 50 that fits into and is positioned within a housing portion 40. FIG. 2 also illustrates a bottom or support 30 that functions much like an inner spring for use in bed arrangements in which the mattress system is separately supported and not moveable as the mattress system 11 in FIG. 1.
Chamber portion 50 seen in FIG. 2 is a matrix of inflatable chambers such as representative chambers 50A-E. The size and shape of selected chambers can vary. For example fewer chambers are needed in the upper portion 20A of a bed like bed 20. As stated, the chamber portion 50 is positioned within a separate housing portion or base 40 that may be positioned. The base 40 may be positioned on top of the bottom or support 30 or on top of the frame 15 and more specifically the housing 16C.
As constructed, the mattress 20 is a parallelepiped which is also generally rectangular in projection and sized in height 40H, in length 40I and in width 27 to fit on or in a suitable bed support like support 30 or on a bed frame like the housing 16C (FIG. 1). Thus, a mattress may be sized to fit into or on other conventional bed frames. Double, queen size and king size versions are contemplated. The mattress for larger versions may have one base 40 sized to accommodate two separate sets of chambers 50 in a side by side relationship.
The container or base 40 of the mattress 20 of FIGS. 1 and 2 has an upper surface 40B that may be, and in this embodiment is, the same as the surface of the mattress 20D. The base 40 also has a bottom surface 40E and sides 40F, 40G, 40J and 40K. The bottom surface 40E and sides 40F, 40G, 40J and 40K are each made of a material that selected to be flexible and have suitable wearing characteristics to resist punctures, is cleanable, and relatively strong. A wide variety of synthetic products including plastic (e.g., polypropylene) or plastic-like materials may be used to fabricate the base 40. In some cases, the mattress 20 may have padding for comfort and insulation as discussed more fully hereinafter.
In FIG. 2, the base 40 is shown having a lid 45 which is discussed more fully below. The bottom surface 40E and the sides 40F and 40G may be made of a thicker or more durable material in relation to the upper surface so the mattress is able to maintain a reasonable degree of rigidity when inflated. However, the upper and lower surfaces 40D and 40E as well as the sides 40F and 40G may be made of the same material.
As seen in FIG. 2, the bottom or support 30 depicted is a generally rectangular structure having opposite side walls 31 and 32 and opposite ends 33 and 34. It is here shown to have four separate compartments 46, 47, 48 and 49 separated by compartment dividers 35, 36, 37 which extend between the lower surface 39A and the upper surface 39B to provide structural support to the side walls 31 and 32 as well as support for the upper surface 39B (shown in cut-away). The bottom or support 30 functions to support the base 40 with the chambers 50 in the base and a user 10 positioned thereon. The surface 39B and preferably the bottom surface 39A extends between the sides 31 and 31 and the ends 33 and 34. The number of compartments 46-49 in the bottom or support 30 may vary. The compartments 46-49 may be filled with any suitable material to provide the rigid support desired. Latex, coil springs, leaf springs, spring lattice structures and even liquid or air chambers may be used to provide the desired rigidity and support.
In some embodiments, the cover 45 may function as the upper surface 40B. It would then be configured to be securely fastened to the side walls 40F, 40G, 40J and 40K and more specifically to the upper rim 41 of the side walls. 40F, 40G, 40J and 40K by any suitable means such as a zipper. For example, the adjoining edges may be formed with a zipper like arrangement much like that found on Zip-Lock® bags. If one edge like edge 43 remains zipped, the edge then function much like a hinge so the cover or lid 45 may be removed. Of course the cover 45 is not rigid as shown with a plastic like material of construction. The chamber has a suitable aperture like aperture 40A to allow tubes from each chamber such as chambers 50A-E to be assembled into a tube bundle 17 to pass through aperture 40A in the bottom 40E for further connection to the chassis 19 of the controller 14 for supplying and removing fluid (e.g., air) for the purpose of inflation and deflation.
In other configurations, the lid 45 may be made from a fabric such as Lycra®. If the side wall 43 of chamber 40 is formed with a rib along an edge 43A, conventional sewing stitches may be used to secure removable lid 45 to the rib at the edge 43A. Removable lid 45 is then secured to side walls upper edge 41 with suitable fasteners that can include buttons, snaps, interactive hook and pile fasteners (e.g., Velcro® fasteners) as well as other forms of zippers. Virtually any suitable mechanism to associate the cover 45 to the chamber 40 may be used to effect a mechanical association.
While the chambers 50 shown in FIG. 2 are shaped essentially like a brick, they may be in any suitable configuration or shape desired. For example, the chambers maybe cube like or even cylindrical in shape. Optional and solid (e.g., neoprene) material 50A may be used to space selected chambers 50B and 50C in any suitable or desired pattern. As shown in FIG. 2A, the chambers in one or more or all of the sections 20A, 20B and 20C may be formed in a thin wafer like form. That is one or more chambers like chambers 50D and 50E may be stacked one on top of the other. Alternately, a non inflatable portion 50G may be positioned between inflatable chambers 50F and 50H. In other words, the chambers may be assembled in a large number of configurations to meet any desired support configuration.
In the illustrated embodiment, the mattress system 11 is sized or depicted as an approximate single or twin mattress for use in a typical hospital bed. However, any mattress size (e.g. king, queen, or full) may be manufactured using the inflatable multi-cell design described herein without departing from the intended scope and spirit of the invention.
The hospital bed mattress 20 of FIGS. 1 and 2 functionally may be viewed as having the three portions or sections 20A, 20B and 20C as hereinbefore noted. In use, the gluteus maximus of the user would be positioned in and supported by the middle portion 20B. The back of the user would be supported by the upper portion 20A, and the user's lower extremities 10B and 10C (e.g., legs, thighs and feet) would be supported by the lower portion 20C.
In use, it is possible that one or more chambers of the matrix 50, such as chambers 50 A-E may be damaged and start to leak. In that event, it is desirable that coverings be removable, such as cover 45, so that one may access a chamber and be able to effect a repairs (e.g., affix a suitable patch). Thus, any of the plurality of inflatable chambers 50 within inflatable mattress system 20 may be easily replaced or repaired.
Referring now to FIG. 3A, an alternate chamber arrangement 100 comparable to chambers 50 is depicted. The chamber arrangement 100 is sized to fit within a base like base 40; and it has multiple cells or inflatable chambers of differing sizes arranged in an advantageous manner to minimize the occurrence of bedsores in a patient. Specifically, the chamber arrangement 100 includes a group of elongated inflatable chambers 120, 121, 122 positioned to support the head of an occupant 10 when the occupant is positioned normally on the chamber arrangement 100. The elongated inflatable chambers 120, 121, 122 are each rectangular in shape and sized to extend the width 123 of the chamber arrangement 100. In alternate configurations, the chambers 120, 121 and 122 may extend a distance 124A and 124B from the centerline 124D of the mattress selected to provide suitable support for the head with an associated portion 124C not typically associated with supporting a patient made of a suitable flexible material like neoprene.
The chamber arrangement 100 of FIG. 3A also has a plurality of large inflatable chambers here shown to be chambers 111, 112 and 113. They are located so that when an occupant is positioned on the chamber arrangement 100, the occupant's shoulders are positioned to be supported by chambers 111, 112 and 113. A larger chamber is shown because more support is typically desired for the user from the neck area down toward the middle of the back. At the same time, this area is not typically prone to the incidence of bedsores.
In FIG. 3A, the middle of the chamber arrangement 100 is shown with large brick- like chambers 106, 107, 108 and 109 surrounding a matrix of 9 cube-like interior chambers 125-133. The matrix of chambers 125-133 is positioned to support the small of the back and the gluteus maximus of the occupant like occupant or patient 10 when positioned normally on the chamber arrangement 100 with his or her head proximate chambers 120-122. The risk of bedsores by an essentially chronically immobile occupant over a longer period of time is typically higher in this region. In turn the support can be varied by inflating and deflating selected chambers of the matrix of chambers 125-133 to vary the supporting locations to avoid the creation of bedsores at various supported locations. The larger outer chambers 106-109 do not typically provide support to torso of the occupant. Rather they will typically be supporting the arms and hands which weigh less and which have less skin or surface in contact with the chamber arrangement 100 and thus do not typically experience bedsores.
The chamber arrangement 100 of FIG. 3A next has a series of larger chambers 134, 135 and 136 which will be proximate the thighs of a chronically immobile user positioned normally on the chamber arrangement 100. The skeletal configuration of the thighs keeps them suspended. That is the weight of the thighs are borne more by the hips and the knees than by the mattress. Thus the incidence of bedsores is typically minimal in the region of the thighs.
The lower portion of the chamber arrangement 100 in FIG. 3A has a matrix of smaller chambers 137-142 positioned to support the feet and some portion of the lower leg or calf area. These chambers 137-142 are inflated and deflated in different patterns or configurations to vary the support to the feet and lower calves to reduce the incidence of bedsores. Inasmuch as the feet are typically positioned close to the centerline 124D of the bed, the outer chambers 104 and 105 are larger and may be about twice the size of the a chambers 137-142 of the matrix.
Selective inflation and deflation of the illustrated small inflatable chambers provides a variation of the pressure at points of contact between the mattress surface and the body (skin) at the most common places for the development of bedsores on a bed-ridden individual. It is believed that the change in location may impact on blood flow to the skin and also allow ventilation. The system operates so that the pressure in the small chambers varies from, for example, about 1.0 to 1.1 pounds per square inch (psi). While representing less than a 10% change in pressure, the result structurally is notable. The other larger chambers 104-109, 134-136 and 111-113 are located adjacent the group of small inflatable chambers but typically are not supporting the body of a chronically immobile person.
In a preferred embodiment, the inflatable chambers are sized and placed according to the average weight and size of a typical human body. In other configurations, inflatable chambers may be larger sized to accommodate the weight of a very large person or smaller sized to accommodate the weight of a baby or child. Preferably, elongated inflatable chambers 120, 121, 122 are sized in a range of approximately 36.0 inches by 3.7 inches to 37 inches by 4.7 inches, and are preferably 36.5 inches by 4.2 inches. Large inflatable chambers, 111, 112, 113 are sized in a range of approximately 13.0 inches by 11.3 inches to 14.0 inches by 12.3 inches, and are preferably 12.5 inches by 12.8 inches. Small inflatable chambers 137-142 are sized in a range of approximately 8.3 inches by 6.4 inches to 9.3 inches by 7.4 inches, and are preferably 8.8 inches by 6.9 inches. Inflatable chambers 125-133 are sized in a range of approximately 13.0 inches by 6.4 inches to 14.0 inches by 7.4 inches, and are preferably 12.5 inches by 6.9 inches. Preferably, elongated inflatable chambers, large inflatable chambers, small inflatable chambers and medium inflatable chambers are approximately 3.0 inches in height 143.
The inflatable chambers illustrated in FIG. 3A are not fluidly connected, so each inflatable chamber may be individually inflated and deflated. In some configurations, each chamber is separate and removable from the others. In such an arrangement the individual chambers are easily removable; and thus one may replace an inoperative or defective chamber.
It has been found that in some instances, bedsores are more easily generated on the heels of a user as well as along the back of the calves. To help reduce the incidence of bedsores a separate chamber positioned to elevate the feet and calves of the chronically immobile occupant has been found useful.
FIG. 3B illustrates one embodiment of a limb elevation chamber 25 useful to elevate the feet and calves of a chronically immobile occupant. Elevation chamber 25 has a top surface 26, a bottom surface 27, a right support strap 28 and a left support strap 29. In the illustrated embodiment, elevation chamber 25 is shown as substantially rectangular in projection with an accurate top surface 26. It in effect looks like half of a cylinder. However, elevation chambers 25 of varying shapes such as circular, spherical, cylindrical, toroidal, ovular, triangular, and other shape that is desired so long as it may be positioned to elevate the feet and calves of the chronically immobile occupant. It is also contemplated that a limb elevation chamber 25 can be formed to have multiple separately inflatable and deflatable compartments 26A, 26B and 26C. Each compartment 26A, 26B and 26C will have its own separate connector such as connector 31A (as hereinafter described) to receive and supply fluid for selective inflation and deflation.
In one embodiment, bottom surface 27 is approximately 12 inches wide 27A and 35 inches long 27B. The curved or semicircular top surface 26 has a height of about 3 to 5 inches and preferably about 4 inches high 26A. The height 26A is selected so that the chamber 25 will elevate the feet and calves or other limb of the chronically immobile occupant sufficiently to allow the blood flow to be normal and some air to circulate to reduce the incidence of bedsores. The enumerated dimensions are provided as illustrative, and should not be limiting, as other dimensions may be used as desired.
In operation, the bottom surface 27 of the chamber 25 lies flat on the surface of a mattress like mattress 20 with the straps 29A and 29B extending over and along the sides (e.g., sides 33 and 34 in FIG. 1). The top surface 26 supports one or possibly several body parts of a patient. For example, an individual's ankles, calves or thighs may be placed on top surface 26 so as to elevate the feet and lower legs or calves and keep them from contact or substantial contact with the associated mattress. In another embodiment, the chamber may be positioned to elevate an individual's arm so as to elevate the hand, forearm and elbow from the surface of the mattress system 20.
Support straps 29A and 29B are sized to extend and run vertically along the edges of mattress 20 to secure elevation chamber 25 to the surface of a mattress like mattress 20. In one embodiment, straps 29A and 29B are substantially as long as the depth of the mattress and are affixed to the sides of the mattress. For example, straps 29A and 29B are approximately 5 inches long and 12 inches wide, although straps of other lengths and widths are contemplated and fall within the scope of the invention. In another embodiment, the inside walls 29E and 29F of straps 29A and 29B are surfaced with one part 29G (see FIG. 1) of Velcro® hook and pile fasteners 29C and 29D positioned to interact with a suitable hook or pile portion affixed to the sheet or similar bed covering wrapped about the mattress such as mattress 20. The part 29G is affixed to a sheet or similar bed covering to have a length 29H that allows the user to secure the limb chamber 25 along the length or axis 21 of the mattress 20. That is, the straps 29A and 29B with hook and pile fasteners function as a securing means for removably coupling the straps 29A and 29B and in turn the chamber 25 to the mattress 20 of a system like system 11. In addition to Velcro® connectors, other securing means may be used to either fixedly attach or removably attach straps 29A and 29B to the sides of mattress system 20. For example, straps 29A and 29B may be long enough to wrap around the underside of mattress system 20 and attach to each other or be held in place by the weight of the mattress 20. Alternately, the straps 29A and 29B may include a malleable metal piece that can bend about the mattress or that can clamp or grip the mattress. Alternately, the straps 29A and 29B can be secured using a button arrangement, a snap arrangement, hooks or the like. It is presently contemplated that a straps 29A and 29B are preferably made of a suitable plastic or cloth with a length so they can be tucked under and between the mattress 20 and the support thereunder 16C (FIG. 1).
Elevation chamber 25 is constructed of any substantially non-porous, flexible material. For example, elevation chamber 25 may be manufactured of a vinyl material, the thickness of the material falling within a range from about 0.015 inches to about 0.04 inches, and preferably, is 0.02 inches. Any similar material may be used. A suitable material should be sealable to create an interior volume in the interior of the elevation chamber 25, such that a fluid may be introduced to inflate the cell. In one preferred embodiment, one surface of the inflatable chamber is constructed of the non-porous, flexible material. However, one or more of the surfaces may be manufactured of the flexible material and the remaining surfaces may be manufactured of a different material.
The top surface 26 is relatively smooth and adapted to support at least a portion of the weight of an individual (e.g., weight of one or both legs) positioned on the surface of the elevation chamber 25. The bottom surface 27 or the top surface 26 has a chamber connector 31A that either introduces fluid into or releases fluid from the inflatable chamber located interior to elevation chamber 25. Chamber connector 31A is positioned on any surface of elevation chamber 25 but is preferably located on the bottom surface 27 or on a sidewall 31B or 31C. It is configured to connect to a conduit means for communicating fluid to and from the interior volume 27A. In the illustrated embodiment, chamber connector 31A is an aperture with a fitting formed in the bottom of elevation chamber 25. However, chamber connector 31A may be any element suitable for fluidly communicating between the interior volume of elevation chamber 25 and any element that supplies, releases or measures fluid such as, for example, the chassis 19 of controller 14 (FIG. 1). Suitable barb connectors and bayonet connectors may also be used and positioned in an suitable indentation formed in the bottom 27.
In one embodiment, a deflectable resistor 31D is secured to a surface of elevation chamber 25 to detect the presence or absence of a pressure point, such as a patient's weight, on the chamber. In a preferred embodiment, deflectable resistor 31D is secured to the top surface 26. Details of deflectable sensor 31D are further described in U.S. Pat. No. 5,583,476 (Langford). With a voltage applied to the deflectable sensor 31D, the deflectable sensor 31D can supply a signal reflecting the deflection of the surface 26 caused by the users limbs such as limbs 10B and 10C. The degree of deflection can reflect inflation as well as the location of the supported extremities. Elevation chamber 25 may not have a deflectable sensor secured to any surface, in which case elevation chamber 25 is simply inflated and deflated manually.
FIGS. 4, 5, and 6 illustrate, respectively, a front view, a bottom view and a top view of an alternate inflatable chamber 140. Inflatable chamber 140 has a top surface 151 and a bottom surface 152. In the illustrated embodiment, inflatable chamber 140 is a half cylinder and is substantially rectangular in projection. However, inflatable chambers of varying shapes such as circular, spherical, cylindrical, toroidal, ovular, triangular, and other shapes could be used as well for specific applications.
Inflatable chamber 140 is constructed of any substantially non-porous, flexible material. For example, inflatable chamber 140 may be manufactured of a vinyl material. The thickness of the vinyl material is typically within a range from about 0.015 inches to about 0.04 inches, and preferably, is about 0.02 inches. Any similar material may be used so long as it is suitable for the formation of a fluid retaining chamber. Thus a fluid (e.g., air, nitrogen) may be introduced to inflate the chamber 140 and is sealed so that the fluid does not escape. In one preferred embodiment, the outer or upper surface 151 of the inflatable chamber 140 is constructed of the non-porous, flexible material. However, at least the bottom surface 152 of the inflatable chamber 140 may be manufactured of the a different material that is not porous and rigid. The bottom surface 152 may be a solid in some applications.
The top surface 151 is relatively smooth and adapted to support at least a portion of the weight of an individual positioned on the surface of the inflatable mattress system 120 of FIG. 3A. The bottom surface 152 has a chamber connector 155 that either introduces fluid into or releases fluid from the interior volume of inflatable chamber 140. Chamber connector 155 is positioned on any surface of inflatable chamber 140 and is configured to connect to a conduit for communicating fluid to and from the interior volume of inflatable chamber 140. In the illustrated embodiment, chamber connector 155 is an aperture with a barb connector 156 sealingly fitted into the aperture. The barb connector 156 is sized to receive a conduit for connection to the a chassis like chassis 19. A separate hose clamp may be positioned over the conduit proximate the barb to effect a secure mechanical connection. The chamber connector 155 is preferably positioned in a recess in the bottom surface 152 so that the fluid chamber 140 may rest essentially flat on the surface of the mattress like surface 20D. The chamber connector 155 may be any other device or structure to connect with a conduit and suitable for fluidly communicating between the interior volume of inflatable chamber 140 and any element that supplies, releases or measures fluid such as, for example, a valve, a connector, a PVC or metal conduit, a female or male adapter or a liquid tight flexible conduit and fitting.
A deflectable sensor 150, such as a deflectable resistor, is secured to a surface of inflatable chamber 140 to detect the level of deflection of the surface 151 and in turn the degree of inflation of the chamber 140. It may also be used in some applications to sense the presence or absence of a pressure point that may be caused by the presence of a user's extremities. In a preferred embodiment, deflectable resistor 150 is secured to the top surface 151. Deflectable resistor 150 consists of a substrate with an electrical conductor thereon that predictably changes in electrical conductivity as it is bent. The change in the inflatable chamber 140 from a first configuration, i.e. a first inflated position, to a second configuration, i.e. a second inflated position, varies the resistance of the deflectable resistor 150 from a first resistance to a second resistance in a predictable way. At any time, the resistance is measured by applying an electrical signal such as a voltage or a current to the deflectable resistor 150. An electrical connection or connections is made to deflectable resistor 150 to capture the deflection information so as to determine the amount of bending or movement that occurs on top surface 151 between a first inflated position and a second inflated position of the inflation chamber 140, referred to herein as a deflection signal that is reflective of the movement of the inflation chamber 140.
A suitable deflectable resistor for purposes of detecting a pressure point on the surface of inflatable chamber 140 is a Bend Sensor® detector manufactured by Flex Point Sensor System, Inc. of Draper, Salt Lake County, Utah. It is also described in U.S. Pat. Nos. 5,157,372 and 5,583,476, the disclosures of which is hereby incorporated by reference for all purposes. Deflectable resistor 150 is affixed to the surface of inflatable chamber 140 by any suitable means such as glue. It is preferably is affixed by a pressure sensitive adhesive that adheres to top surface 151 without affecting the integrity of the material used to manufacture deflectable resistor 150.
Referring now to FIG. 7A, a block diagram illustrating the electrical and mechanical elements for controlling the operation of the inflatable mattress system of the present invention is shown. In the illustrated embodiment, a controller 200 comparable to controller 14 (FIG. 1) is communicatively coupled to a processor 205 which operate together to provide for the selective introduction, discharge and measurement of a fluid within the inflatable chambers 220, 225, 230 and an elevation chamber 280 based upon a deflection signal received from the deflectable resistors 235, 240, 245 and 285. Although three inflatable chambers 220, 225, 230 and one elevation chamber 280 are illustrated and described with respect to FIG. 7A, any lesser or greater number of inflatable chambers and elevation chambers may be used depending upon the particular needs of the desired inflatable mattress system.
In the particular device illustrated, controller 200 is comprised of valve controller 275, fluid controller 265 and reading device 270. In alternate embodiments, controller 200 may be a mechanical or electrical device that incorporates the functions and operations of valve controller 275, fluid controller 265 and reading device 270 in either a single device or multiple devices. Valve controller 275 controls the operation of valve assembly 215 by sending a series of signals to the valve assembly 215 to operate to supply fluid from source 212 to the chambers 220, 225, 230 and 280 one at a time or in a suitable combination based on the particular chambers involved. In this embodiment, the valve 215 performs various mechanical operations, such as selecting one or more particular inflatable chambers for inflation, deflation or measurement. Fluid controller 265 controls the pressure and duration of the flow of fluid from fluid source 212 (comparable to source 13, FIG. 1) to any one of the inflatable chambers 220, 225, 230 and elevation chamber 280 by providing a signal to fluid source 212 to initiate the introduction of fluid to inflate a selected inflatable chamber. Reading device 270 receives a deflection signal from deflectable resistors 235, 240, 245, 285 and operates to determine the location and amount of an individual's weight that is located on inflatable chambers 220, 225, 230 and elevation chamber 280.
In a preferred embodiment, controller 200 is provided with a processor 205 that includes a programmable integrated circuit such as M30262 manufactured by Renesas. However, any suitable programmable integrated circuit may be used to supply operating commands that control the operation of valve assembly 215 and fluid source 212, as well as receive deflection measurements from the surface of inflatable chambers 220, 225, 230 and elevation chamber 280, as well as pressure measurements from within the respective interior volume of inflatable chambers 220, 225, 230 and elevation chamber 280. For example, processor 205 may include or be embodied in an application specific integrated circuit.
Controller 200 is also coupled to valve assembly 215 through a pressure sensor 255 for reading the pressure within inflatable chambers 220, 225, 230 and elevation chamber 280. Pressure sensor 255 is typically a pressure transducer capable of measuring the amount of pressure within an inflatable chamber when such as request is issued by either controller 200 or processor 205. However, any suitable pressure measuring device may be used. In operation, controller 200 is instructed to retrieve a pressure reading within a particular inflatable chamber, for example, inflatable chamber 220. Valve assembly 215, via information from valve controller 275, selects inflatable chamber 220 for a reading. Once chamber 220 is chosen, the pressure reading is taken by pressure sensor 255 and relayed to processor 205 via controller 200.
Processor 205 preferably comprises any computer processor capable of executing a series of instructions. It is configured to access data from controller 200 and issue commands to controller 200. For example, processor 205 may contain instructions for selecting certain inflatable chambers for inflation or deflation based on deflection information received from deflectable resistors 235, 240, 245, 285. Processor 205 may also contain instructions for randomly selecting inflatable chambers 220, 225, 230 and elevation chamber 280 for inflation and deflation in a particular pattern that provides varying pressure points on the skin of an individual's body, thereby preventing the formation of bedsores.
In the illustrated embodiment, fluid source 212 is a pump 210 which supplies fluid via a fluid passage or conduit to valve assembly 215 through a check valve 260 and a three-way valve 250. Three-way valve 250 allows fluid source 212 to introduce fluid into inflatable chambers 220, 225, 230 and elevation chamber 280 through valve assembly 215. In addition, three-way valve 250 is coupled to the atmosphere through a fluid discharge outlet such that fluid may be removed from inflatable chambers 220, 225, 230 and elevation chamber 280 through valve assembly 215. Check valve 260 preferably has a crack pressure of 0.15 psi, which prevents back flow through to the fluid source 212. Fluid source 212 a pump 210 that draws air from the atmosphere and is sized to provide at least ½ to 2 pounds per square inch of pressure in inflatable chambers 220, 225, 230, and elevation chamber 280. The pump may be a 112 VAC model # DDL15B-121, 23 L/m linear diaphragm pump manufactured by Gast that outputs approximately 5 pounds per square inch of pressure. However, any suitable pump may be used that is sized in accordance with the particular requirements of the inflatable mattress system.
Valve assembly 215 is fluidly coupled to inflatable chambers 220, 225, 230 and elevation chamber 280. In operation and with reference to an operating command received from controller 200, valve assembly 215 selects a particular inflatable chamber (or a plurality of chambers) for inflation or deflation. In inflation mode, valve assembly 215 operates to introduce fluid from fluid source 212 through pump 210 into a selected inflatable chamber. In deflation mode, valve assembly 215 releases fluid into the atmosphere from a selected inflatable chamber using three-way valve 250 as a fluid discharge outlet. Valve assembly 215 may be any suitable element for selectively supplying fluid from a fluid source 212 or communicating fluid away from a mattress system. One particular embodiment of a valve assembly 215 is described in greater detail with reference to FIGS. 8-15.
FIG. 7B illustrates another embodiment of the electrical and mechanical controls of an inflatable mattress system. In this embodiment, limb elevation chamber 290 does not have a deflector resistor secured thereto. Therefore, elevation chamber 290 is inflated and deflated manually. That is, the controller 200 is operated to cause the valve 215 to supply inflation fluid to the elevation chamber 290 and to remove inflation fluid by venting it.
In another embodiment, controller 200 determines the presence of an elevation chamber 25, 280 by querying for an electrical signal from a deflector sensor 31, 285 communicatively coupled to an input on reading device 270 reserved for an elevation chamber 25, 280. If an electrical signal is received by controller 200 from the deflector sensor 31, 285, controller 200 determines that an elevation chamber 25, 280 is present. The controller 205 communicates the presence, or lack thereof, of the elevation chamber 25, 280 to the processor 205, with the processor 205 acting in accordance with its programming instructions.
For an inflatable chamber selection operation, controller 200 establishes that a particular inflatable chamber is to be selected. Processor 205 may instruct controller 200 to select a particular chamber, or cell, or controller 200 may select a particular cell on its own. Controller 200 issues an operating command or signal to valve assembly 215 to a select a particular inflatable chamber, for example inflatable chamber 230. First valve plate 300 rotates relative to second valve plate 305 until aperture 350 or aperture 355 aligns with the outlet aperture 365 corresponding to inflatable chamber 230. Typically, an inflate operation, deflate operation and/or measurement operation follows a selection operation.
For an inflatable chamber inflation operation, controller 200 establishes that selected inflatable chamber 230 is to be filled with fluid. Processor 205 may instruct controller 200 to inflate the selected cell or the instruction may come from controller 200. In the embodiment illustrated in FIG. 7A, fluid controller 265 of controller 200 sends an operating command or signal to fluid source 212 instructing the source to supply fluid into inflatable chamber 230 at a particular strength for a particular duration. Controller 200 also sends an operating command to three-way valve 250 that an inflate operation is about to occur. In response to the signals, three-way valve 250 is placed into the inflate position and fluid flows from fluid source 212 through check valve 260, three way valve 250 and into valve 215.
For an inflatable chamber deflation operation, controller 200 establishes that fluid is to be removed from selected inflatable chamber, or cell, 230. As stated previously for an inflate operation, processor 205 may instruct controller 200 to deflate the selected cell or the instruction may come from controller 200. Controller 200 sends an operating command or signal to three-way valve 250 that a deflate operation is about to occur. In response to the operating command from controller 200, three-way valve 250 is placed into the deflate position, thereby creating a fluid path from valve assembly 215 to the environment to release the fluid.
Controller 200 also receives measurement information regarding the deflection of deflectable resistors 235, 240, 245, 285 located on elevation chamber 280 and inflatable chambers, or cells, 220, 225, 230 respectively. Reading device 270 located within controller 205 is coupled to deflectable resistors 235, 240, 245, 285. At prescribed periods of time, reading device 270 receives deflection signals from deflectable resistors 235, 240, 245, 285. For example, if an individual's body is resting on elevation chamber 280 or inflatable chambers 220, 225, 230, the deflectable resistors 235, 240, 245, 285 sense a certain amount of deflection on one or more of the inflatable chambers 220, 225, 230, and elevation chamber 280. In response, a deflection signal representative of the deflection is transmitted from deflectable resistors 235, 240, 245, 285 to the reading device 270 in controller 200. Reading device 270 then transmits the deflection signals to processor 205, which acts in accordance with its programming instructions to prepare output information for display and to supply operation signals to inflate and deflate in accordance with a preselected desired configuration to support the user 10 on a mattress like mattress 20.
Processor 205 uses the deflection information from deflectable resistors 235, 240, 245, 280 in a variety of ways. For example, the deflection signals sent by the deflectable resistors 235, 240, 245, 280 provides processor 205 with information regarding the position of a human body on elevation chamber 280 and inflatable chambers 220, 225, 230. Processor 205 may then instruct controller 205 to alter the pressure within the interior volumes of elevation chamber 280 and/or inflatable chambers 220, 225, 230 at prescribed intervals to vary the pressure exerted from the surface of the inflatable chambers 220, 225, 230 and elevation chamber 280 on the skin of the individual, thereby reducing the formation of bedsores.
A suitable configuration for valve 215 is fully described and disclosed in U.S. Pat. No. 7,219,380 B2 (Beck) the disclosure of which is hereby incorporated by this reference.
FIG. 8 is an illustration depicting an alternate configuration of a mattress 400. A base 402 is formed with two opposite ends 404 and 406 and two opposite sides 408 and 410. Although the base is shown as a rigid structure, it is preferably made of a suitable material such as vinyl or any other material that is easy to keep clean, and is thick enough to protect the in inflatable chamber member 416 from, for example, accidental punctures, wear and tear. The material is also water resistant to keep fluids from entering and creating mold. The opposite ends 404 and 406 and the sides 408 and 410 of the base 402 define a volume 412 sized to receive therein a bottom foam insert 414 and an inflatable chamber member 416. A cover 418 is shown separate from a zipper member 420. However, the edge 422 of the cover 418 in use is sewn to and along the upper edge 424 of the zipper member 420. The lower edge 426 of the zipper member is sewn to or attached by any suitable means to the edge 428. The zipper 430 of the zipper member 420 extends around the perimeter of the zipper member 420 so that the cover 422 may be removed to access the inflatable chamber member 416 and the bottom foam insert 414. A separate foam insert (not shown) may be placed between the cover 418 and inflatable chamber member 416. The top 418 is here shown as a planar or smooth surface typically made of a synthetic material from a family of available plastics but preferably a biaxial stretchable material like Lycra®. A biaxial stretchable material is preferred because it will deform in both transversely and lengthwise when a user is positioned thereon thereby minimizing the deformation of other chambers and in turn false readings suggesting deflection of other chambers. The material for the top 418 is also one that is susceptible to cleaning with a damp or wet cloth and one that can withstand strong cleaning agents of the type used in a typical hospital or medical care facility. The top 418 may be made in other physical configurations as desired including a “pillow top” variety.
At one end of the illustrated mattress 400 in FIG. 8, the end chamber 432 is sized to be about half the height 434 of the inflatable chamber member 414. In the space 436 under the end chamber 432, a control structure 438 is positioned. The sides 406, 408 and 410 may be adjusted so that the side 406 extends upward toward the end chamber 432 and reward along the bottom 433 of the end chamber to form a notch to receive the control structure 438. That is, the control structure 438 is preferably positioned outside the base 402 so that head from the components in the control structure 438 is not retained within the control structure 438 itself and also the enclosure formed by the base 402 and the top 418 when zipped together. The control structure 438 is shown in exploded view with an enclosure or housing 440 sized to receive a valve structure 442 with a microprocessor board 444 assembled with a plurality of assembly screws 446. The valve structure 442 is connected to a source of air or other fluid (not shown) and configured to direct the air or other fluid to the separate chambers like chamber 432 in the inflatable chamber member 416 via suitable conduits like conduit 448 that extend to selected the chambers in the inflatable chamber member 416 through suitable apertures (not shown) in the wall 406 of the base 402. A hand operator 450 is shown with optional controls 452 (e.g., touch pad) connected by a suitable conductor 454 to the microprocessor 444 to set or select programs that operate the valve structure 442 and direct air or other fluid toward or away from the several chambers of the inflatable chamber member 416. The valve structure 442 is a an assembly of one or more solenoid valves which are operated or activated by electrical signals supplied by the microprocessor incorporated into the board 444. The control structure 438 may contain suitable vents and even a suitable fan (not shown) to remove heat from within the control structure 438. A suitable power supply will also be positioned within the control structure 438 to receive 115 Volt power readily available at a wall plug to the desired power level to operate the solenoid valves 442, the fan if used, and the microprocessor board 444.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. An inflatable mattress system comprising:

a plurality of inflatable chambers assembled to define a support surface to support an occupant having at least one limb, each of said inflatable chambers having at least one wall member forming an interior volume, said wall member being made from a flexible material selected to retain fluid, each of said plurality of inflatable chambers having a chamber connector for fluid communication with said interior volume, said at least one wall member being deflectable between a first inflated position and a second inflated position different from said first inflated position;

a plurality of deflectable resistors each of which predictably varies its electrical resistance upon deflection from a first configuration to a second configuration, each of said plurality of deflectable resistors being attached to said at least one wall member of an inflatable chamber of said plurality of inflatable chambers to deflect between said first configuration and said second configuration upon movement of said at least one wall member between said first inflated position and said second inflated position to generate a deflection signal upon application of electrical power to said deflectable resistors reflective of said inflatable chamber movement;

an inflatable limb elevation chamber configured for positioning on said support surface to support a limb of said occupant, said inflatable limb elevation chamber including at least one elevation chamber wall member having an elevation chamber interior volume, said elevation chamber wall member being made from a flexible material selected to retain fluid, said at least one elevation chamber wall member being deflectable between a first inflated elevation chamber position and a second inflated elevation chamber position different from said first inflated elevation chamber position, said elevation chamber having an elevation chamber connector for fluid communication with said elevation chamber interior volume;

a fluid source for supplying a fluid under pressure into each interior volume of said plurality of inflatable chambers and into said elevation chamber interior volume;

a first conduit means connected to each of said chamber connectors and said elevation chamber connector for communicating fluid to and from said interior volume and said elevation chamber interior volume;

a second conduit means connected to said fluid source for communicating fluid to and from said fluid source;

a discharge means for communicating fluid away from said interior volume and said elevation chamber interior volume;

a valve connected to said first conduit means, said second conduit means and said discharge means, said valve being operable among a first position in which said valve places said first conduit means in communication with said second conduit means for supplying fluid from said fluid source to said interior volume and said elevation chamber interior volume, a second position in which said valve places said first conduit means in fluid communication with said discharge means, and a third position in which said first conduit means is inhibited from communicating fluid to and from said interior volume and said elevation chamber interior volume; and

a controller connected to each of said plurality of deflectable resistors for supplying an electrical signal thereto and for receiving said deflection signal therefrom, said controller being configured to generate operating commands for operating said valve among said first position, said second position and said third position, said controller being connected to said valve to supply said operating commands to said valve.

2. The limb elevation chamber of claim 1, wherein said elevation chamber is removable from said support surface.

3. The inflatable mattress of claim 1, wherein said controller includes a processor having a set of instructions for receiving said deflection signals and deriving an amount of said inflatable chamber movement and directing said controller to deliver said operating commands for placing said valve in said first position, said second position, and said third position.

4. The inflatable mattress of claim 3, wherein said controller further comprises a valve controller, communicatively coupled to said processor and said valve, said valve controller configured to receive an operating command to select at least one of said plurality of inflatable chambers and said elevation chamber in response to a command from said processor.

5. The inflatable mattress of claim 4, wherein said controller further comprises a reading device, communicatively coupled to said processor and said plurality of deflectable resistors, said reading device configured for receiving said deflection signal and transmitting said deflection signal to said processor.

6. The inflatable mattress of claim 5, wherein said controller further comprises a fluid controller, communicatively coupled to said processor and said fluid source, said fluid controller configured for actuating said fluid source in response to an operating command from said processor.

7. The inflatable mattress of claim 1, in which said inflatable limb elevation chamber has at least one elevation chamber deflectable resistor that predictably varies its electrical resistance upon deflection from a first elevation chamber configuration to a second elevation chamber configuration when an electrical signal is applied thereto, said elevation chamber deflectable resistor being attached to said at least one elevation chamber wall member of said elevation chamber to deflect therewith upon movement of said at least one elevation chamber wall member between said first inflated elevation chamber position and said second inflated elevation chamber position for generating an elevation chamber deflection signal reflective of said elevation chamber movement, said elevation chamber deflectable resistor connected to said controller for supplying an electrical signal thereto and for receiving said elevation chamber deflection signal therefrom.

8. An inflatable mattress system comprising:

a plurality of inflatable chambers assembled to define a support surface having a width and a central axis, said support surface being sized to support an occupant having at least one limb, each of said inflatable chambers having at least one wall member forming an interior volume, said wall member being made from a flexible material selected to retain fluid, each of said plurality of inflatable chambers having a chamber connector for fluid communication with said interior volume, said at least one wall member being deflectable between a first inflated position and a second inflated position different from said first inflated position;

a plurality of deflectable resistors each of which predictably varies its electrical resistance upon deflection from a first configuration to a second configuration, each of said plurality of deflectable resistors being attached to said at least one wall member of an inflatable chamber of said plurality of inflatable chambers to deflect from said first configuration to said second configuration upon movement of said at least one wall member between said first position and said second position to generate a deflection signal reflective of said inflatable chamber movement upon application of electrical power to said deflectable resistors;

an inflatable limb elevation chamber configured for positioning on said support surface to support a limb of said occupant, said elevation chamber including at least one elevation chamber wall member forming an elevation chamber interior volume, said elevation chamber wall member being made from a flexible material selected to retain fluid, said at least one elevation chamber wall member being deflectable between a first inflated elevation chamber position and a second inflated elevation chamber position different from said first inflated elevation chamber position, said elevation chamber having an elevation chamber connector for fluid communication with said elevation chamber interior volume, and said elevation chamber being sized to extend substantially normal to said central axis for positioning proximate the feet of the occupant;

a first conduit means connected to said chamber connector and said elevation chamber connector for communicating fluid to and from said interior volume and said elevation chamber interior volume;

a valve connected to said first conduit means, said second conduit means and said discharge means, said valve being operable among a first position in which said valve places said first conduit means in communication with said second conduit means for supplying fluid from said fluid source to said interior volume and said elevation chamber interior volume, a second position in which said valve places said first conduit means in fluid communication with said discharge means; and

a controller connected to each of said plurality deflectable resistors for supplying an electrical signal thereto and for receiving said deflection signal therefrom, said controller being configured to generate operating commands for operating said valve between said first position and said second position said controller being connected to said valve to supply said operating commands to said valve.

9. The inflatable mattress system of claim 8 wherein said limb elevation chamber has a support surface that is arcuate.

10. The inflatable mattress system of claim 8 wherein said limb elevation chamber has means for securing said elevation chamber to said support surface.

11. The inflatable mattress system of claim 10 wherein said means for securing is a member on hook and pile fastener

12. The inflatable mattress system of claim 8 wherein said limb elevation chamber has multiple compartments.

13. The inflatable mattress system of claim 8 wherein said limb elevation chamber extends substantially the width of said support surface.

14. An inflatable limb elevation chamber configured for positioning on a support surface to support a limb of an immobile person on said support surface, said support surface having a width and an axis, said inflatable elevation chamber comprising:

an elevation chamber wall member forming an elevation chamber interior volume, said elevation chamber wall member being made from a flexible material selected to retain fluid, said at least one elevation chamber wall member being deflectable between a first inflated elevation chamber position and a second inflated elevation chamber position different from said first inflated elevation chamber position said elevation chamber being sized to extend substantially normal to said central axis for positioning under the limb of the immobile person thereon;

an elevation chamber connector positioned in a chamber wall for fluid communication with said elevation chamber interior volume and connectable to a source of fluid and a vent to vent fluid from said elevation chamber.

15. The inflatable limb elevation chamber of claim 14 wherein said elevation chamber interior volume has multiple interior chambers with an elevation chamber connector positioned for fluid communication with each of said multiple interior chambers.

16. The inflatable limb elevation chamber of claim 14 wherein said elevation chamber wall member has a deflectable resistor positioned thereon which predictably varies its electrical resistance upon deflection of said elevation chamber wall member from a first configuration to a second configuration to generate a deflection signal reflective of said deflection upon application of electrical power to said deflectable resistor.

17. The inflatable limb elevation chamber of claim 14 wherein said inflatable limb elevation chamber has opposite ends with said elevation chamber wall attached thereto and extending therebetween.

18. The inflatable limb elevation chamber of claim 17 further including a strap extending from each of said opposite ends.

19. The inflatable limb elevation chamber of claim 18 further including securing means attached to each of said straps to secure said inflatable limb elevation chamber to said support surface.

20. The inflatable limb elevation chamber of claim 18 wherein each of said straps is sized to extend from its respective opposite end under said support surface.

21. The inflatable limb elevation chamber of claim 19 wherein said securing means includes one of hook or pile member of a hook and pile fastener affixed to each of said straps and the other of said hook or pile member affixed to said support surface.