Patent Application
20100281619
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.
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.
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:
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
It should be noted that the air has been stated to be the material or fluid used to inflate the chambers 50A-E (
In the embodiment of
In
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
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
Referring now to
Chamber portion 50 seen in
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 (
The container or base 40 of the mattress 20 of
In
As seen in
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
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
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
The chamber arrangement 100 of
In
The chamber arrangement 100 of
The lower portion of the chamber arrangement 100 in
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
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.
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
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
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 (
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.
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
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
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,
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
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
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.
At one end of the illustrated mattress 400 in
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.
