Abstract:
An apparatus is disclosed for selectively adjusting the firmness of various surface regions of a mattress, including regions providing lumbar, thoracic, and pelvic support to a user. The mattress comprises a plurality of removable tubes filled with a variety of materials, which tubes are inflatable and deflatable by a compressor operating in accordance with the programming of a user. The user is supported on the mattress by, inter alia, the removable, subsurface, tubing which is pressurized by its hybrid material-air contents.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to mattresses, and more particularly relates to mattresses comprised of air-inflatable zones mattresses comprising foams, bladders, gels, visco foams and the like. 
         [0003]    2. Description of the Related Art 
         [0004]    Air mattresses and airbeds are well-known to those of skill in the art. Both air mattresses and airbeds are inflated to support the weight of one or more users with pressurized air, and are usually made from reinforced urethane plastic, vinyl, rubber and the like. Air mattresses are inflated manually by blowing through a valve, or through use of a foot pump, an electric pump, and the like. 
         [0005]    Like spring mattresses, as users lay for long periods of time upon traditional air mattresses, irregularly shaped portions of their bodies bear greater amounts of body weight than otherly shaped portions of their bodies, causing discomfort and potentially causing bedsores, particularly with respect to patients who are permanently bedridden and for whom bedsores can pose life-threatening risks. 
         [0006]    Memory foam mattresses are usually made of viscoelastic polyurethane foam, and are also well-known to those of skill in the art. Memory foam mattresses vary in density and thickness, but have an open cell structure that moulds to the body shape of a user laying upon them. Memory foam has the ability to mould beneath its users&#39; bodies and to relieve uncomfortable pressure points on the users&#39; bodies which are agitated by other types of mattresses, including spring and air mattresses. Thus, memory foam mattresses have been known to reduce the severity of bedsores caused by continued use of other types of mattresses. 
         [0007]    However, even memory foam mattresses cause pressure on certain points on users&#39; bodies more than others. Traditional memory foam mattresses provide users with no means of reducing the pressure, density, or indentation force deflection (IFD) rating (a measurement of the property of firmness) of particularized regions of the mattress used by users for lumbar, thoracic, or clavicle support. 
         [0008]    Many users of memory foam mattresses, like all mattresses, find after time that they wish to adjust even uniformly applied mattress pressure to relieve certain areas of their bodies during sleep. Users become fatigued and discomforted by pressure applied constantly to any portion of their bodies. 
         [0009]    Mattresses currently available in the industry provide no effective means of temporarily altering the density or IFD ratings of particularized regions of a single mattress. 
       SUMMARY OF THE INVENTION 
       [0010]    From the foregoing discussion, it should be apparent that a need exists for a selectively inflatable mattress. Beneficially, such an apparatus would overcome many of the difficulties with prior art by providing a means to selectively inflate and deflate various regions of a foam mattress in order to achieve greater pressure relief and comfort. 
         [0011]    The present invention has been developed in response to the state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available mattresses. Accordingly, the present invention teaches an apparatus for selectively adjusting the firmness of various surface regions of a mattress, including regions providing lumbar, thoracic, and pelvic support to a user. The present invention has been developed to provide an inflatable air mattress comprising a mattress body defining a plurality of cylindrical or other shaped cavities, the mattress body having longitudinal ends and lateral sides defining a perimeter thereof, the mattress body comprising a top surface and a bottom surface, the top surface being comprised of one of: viscoelastic polyurethane foam, foam, gel, fabric, feathers, and other relatively soft and otherwise conformable materials. 
         [0012]    The mattress body further comprises a plurality of inflatable tubes with impermeable and flexible exterior surfaces, the inflatable tubes insertably and removably positioned within the plurality of cylindrical or other shaped cavities. The inflatable tubes have hollow cores interiorly isolated atmospherically from ambient air and filled with one of: permeable, viscoelastic polyurethane foam, foam, and/or other permeable materials. The inflatable tubes are pneumatically connected with flexible hosing to one or more air compressors; and one or more air compressors connected with the flexible hosing to the inflatable tubes. 
         [0013]    In some embodiments, the plurality of cavities run laterally through, and across the width of, the mattress body. In other embodiments, the plurality of cavities run longitudinally through, and across the length of, the mattress body. In still further embodiments, the plurality of cylindrical and/or other shaped tubes are in fluid connection with one another. 
         [0014]    In some embodiments, the one or more air compressors are housed within the headboard of a bed. In other embodiments, the one or more of the plurality of tubes are positioned in a lengthwise orientation in the mattress body that is orthogonal to the lengthwise orientation of one or more of the plurality of tubes. 
         [0015]    In still further embodiments, the one or more of the inflatable tubes are cubical in shape, comprising four elongated, planar sides. The volume of one or more of the inflatable tubes may vary from the volume of one or more of the inflatable tubes in some embodiments. 
         [0016]    The one or more air compressors may be configured to automatically perform one or more of the following functions: inflate each of the inflatable tubes to an equal pressure after an irregularly shaped object is laid upon the mattress body; inflate each inflatable tube to a pressure preselected for that inflatable tube, the pressure varying from one inflatable tube to another; deflate each inflatable tube to a pressure preselected for that inflatable tube, the pressure varying from one inflatable tube to another; randomly alternate the pressure of each inflatable tube at predefined intervals throughout a preselected period of time; and cyclically alternate the pressure of each inflatable tube at predefined intervals throughout a preselected period of time in accordance with a predetermined schedule. 
         [0017]    The mattress body, in some embodiments, may alternatively comprise a first set of inflatable tubes with impermeable and flexible exterior surfaces, the first set of inflatable tubes insertably and removably positioned within the plurality of elongated cavities, the first set of inflatable tubes having hollow cores interiorly isolated atmospherically from ambient air and filled with one of: permeable, viscoelastic polyurethane foam, foam, polymer gel, silicone gel, and other permeable material. 
         [0018]    The first set of inflatable tubes may be pneumatically connected with flexible hosing to one or more air compressors, wherein the first set of inflatable tubes laterally traverse only the left lateral side of the mattress body. 
         [0019]    The mattress body may also comprise a second set of inflatable tubes with impermeable and flexible exterior surfaces, the second set of inflatable tubes insertabley and removabley positioned within the plurality of elongated cavities, having hollow cores interiorly isolated atmospherically from ambient air and filled with one of: permeable, viscoelastic polyurethane foam, foam, polymer gel, silicone gel, and other permeable material. 
         [0020]    The second set of inflatable tubes are pneumatically connected with flexible hosing to one or more air compressors, and laterally traverse only the right lateral side of the mattress body. In this embodiment, one or more air compressors connected with the flexible hosing to the first set of inflatable tubes; and one or more air compressors connected with the flexible hosing to the second set of inflatable tubes. 
         [0021]    In some embodiments, the inflatable tubes and the second set of inflatable tubes are cubical in shape, comprising four elongated, planar sides. 
         [0022]    In other embodiments, the inflatable mattress comprises a rectangular upper mattress body having longitudinal ends and lateral sides defining a perimeter thereof; an inflatable air bladder disposed underneath the upper mattress body which confronts and is connected to the upper mattress body; a central mattress body disposed between the inflatable air bladder and a lower mattress body, connected to the upper mattress body and the lower mattress body, the central mattress body defining a plurality of cylindrical cavities, the central mattress body comprising one of: viscoelastic polyurethane foam, foam, polymer gel, silicone gel, and other permeable material. 
         [0023]    In still further embodiments, the inflatable mattress comprises a lower mattress body disposed beneath the upper mattress body and confronting the bottom of said central mattress body. 
         [0024]    These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
           [0026]      FIG. 1A  is perspective view of a selectively inflatable mattress in accordance with the present invention; 
           [0027]      FIG. 1B  is perspective view of another embodiment of a selectively inflatable mattress in accordance with the present invention; 
           [0028]      FIG. 2A  is a perspective view of inflatable tubes in accordance with the present invention; 
           [0029]      FIG. 2B  is a perspective view of hoses and inflatable tubes in accordance with the present invention; 
           [0030]      FIG. 3A  is cross-sectional top elevation view of a selectively inflatable mattress in accordance with the present invention; 
           [0031]      FIG. 3B  is cross-sectional top elevation view of another embodiment of a selectively inflatable mattress in accordance with the present invention; 
           [0032]      FIG. 3C  is cross-sectional top elevation view of another embodiment of a selectively inflatable mattress in accordance with the present invention; 
           [0033]      FIG. 4A  is cross-sectional side view of a selectively inflatable mattress in accordance with the present invention; 
           [0034]      FIG. 4B  is cross-sectional side view of another embodiment of a selectively inflatable mattress in accordance with the present invention; 
           [0035]      FIG. 4C  is cross-sectional side view of another embodiment of a selectively inflatable mattress in accordance with the present invention; and 
           [0036]      FIG. 5  is an elevated perspective view of another embodiment of a selectively inflatable mattress in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0037]    Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
         [0038]    Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
         [0039]    The schematic flow chart diagrams that follow are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. 
         [0040]      FIG. 1A  is perspective view of a selectively inflatable mattress  100  in accordance with the present invention. The selectively inflatable mattress  100  comprises a mattress body  102 , a tube  104   a,  a tube  104   b,  a tube  104   c,  a tube  104   d,  a tube  104   e,  a tube  104   f,  a tube  104   g,  a tube  104   h,  a tube  104   i,  and a headboard  106 . 
         [0041]    The mattress body  102  comprises a top longitudinal end adjacent to the headboard  106 , a bottom longitudinal end oppose the top longitudinal end, and left and right lateral sides further described below in relation to  FIG. 3C . 
         [0042]    The mattress body  102 , in the preferred embodiment, is generally rectangular in shape. In alternative embodiments, the mattress body  102  may be circular, triangular, and the like. 
         [0043]    The mattress body  102  may be formed, wholly or partially, of viscoelastic polyurethane foam, foam, polymer gel, silicone gel, and/or other materials well-known to those of skill in the art and commonly used in the manufacture of mattresses. 
         [0044]    The dimensions of the mattress may vary across differing embodiments from only ten inches to more than ten feet. The mattress body  102  may conform to the dimensions of commonly denominated mattresses, including twin, full, queen, king, California king, and the like. The density, thickness, and firmness of the mattress body  102  may vary greatly from one embodiment to another, as measured by standards well-known to those of skill in the art, including indentation force deflection (IFD) rating, a measure of firmness. 
         [0045]    In the shown embodiment, the mattress body  102  forms and defines nine (9) elongated, cylindrical cavities running from one lateral side to another of the mattress body  102 . These cavities are hollow, and filled in the shown embodiment by insertable tubes  104   a - i.    
         [0046]    The tubes  104   a - i  are inflatable, and made of impermeable and flexible materials well-known to those of skill in the art. The tubes  104   a - i  are insertable and removable into the elongated cavities formed by the mattress body  102 . The hollow insides of tubes  104   a - i  are isolated atmospherically from the ambient air surrounding the mattress body  102 , and filled, in the preferred embodiment, with one of permeable, viscoelastic polyurethane foam (“memory foam”), foam, polymer gel, silicone gel, and bed springs. 
         [0047]    In the preferred embodiment, the tubes  104   a - i  are filled with foam and/or memory foam, and the mattress body  102  comprises foam and/or memory foam. In the preferred embodiment, the cell structure of the foam and/or memory foam filling the tubes  104   a - i  is more open than the cell structure of the foam and/or memory foam comprised by the mattress body  102 , thus, in the preferred embodiment, the density of the foam and/or memory foam comprised by the tubes  104   a - i  is less dense than that of the mattress body  102 . 
         [0048]    The tubes  104   a - i  and cavities, in the shown embodiment, laterally traverse the mattress body  102 . In various embodiments of the present invention, the tubes  104   a - i  traverse the mattress body  102  longitudinally rather than laterally. In still further embodiments of the present invention, the tubes  104   a - i  traverse the mattress body  102  across non-adjacent paths. 
         [0049]    The tubes  104   a - i  are positioned in close enough proximity to the surface of the mattress body  102  so as to affect, change, influence and/or impart value to the IFD ratings of the surface of the mattress body  102 . 
         [0050]      FIG. 1B  is perspective view of another embodiment of a selectively inflatable mattress  150  in accordance with the present invention. The selectively inflatable mattress  150  comprises a mattress body  102 , a tube  104   a,  a tube  104   b,  a tube  104   c,  a tube  104   d,  a tube  104   e,  a tube  104   f,  a tube  104   g,  a tube  104   h,  a tube  104   i,  a headboard  106 , a hose  152   a,  a hose  152   b,  a hose  152   c,  a hose  152   d,  a hose  152   e,  a hose  152   f,  a hose  152   g,  a hose  152   h,  a hose  152   i,  and a compressor  154 . 
         [0051]    The mattress body  102  and tubes  104   a - i  are substantially described above in relation to  FIG. 1A . 
         [0052]    The hoses  152   a - i , or hosing  152   a - i , in the shown embodiment, comprise flexible or rigid air hosing well-known to those of skill in the art, including flexible nylon, polyethylene or PVC hosing. The hoses  152   a - i  interconnect the tubes  104   a - i  and the one or more compressors  154 . 
         [0053]    The tubes  104   a - i  are pneumatically connected with flexible hosing  152   a - i  to one or more air compressors  154  which can be activated by a user to inflate or deflate one or more of the tubes  104   a - i . In some embodiments of the present invention, the one or more air compressors  154  are embedded and enclosed in the headboard  106 . 
         [0054]    In various embodiments of the present invention, the one or more compressors  154  are configured to automatically inflate each of the inflatable tubes to an equal pressure after an irregularly shaped object is laid upon the mattress body. In other embodiments, the compressors  154  are configured to inflate each inflatable tube  104   a - i  to a pressure preselected for that inflatable tube  104 , the pressure varying from one inflatable tube  104  to another, thus imparting preselected firmness to the region of the mattress body  102  overlaying the tube  104 . 
         [0055]    In other embodiments of the present invention, the compressors  154  are configured to automatically deflate each of the tubes  104   a - i  to a pressure preselected for that inflatable tube  104 , the pressure varying from one inflatable tube to another. 
         [0056]    In still further embodiments of the present invention, the compressor  154  is configured to randomly alternate the pressure of each inflatable tube at predefined intervals throughout a preselected period of time; and/or to cyclically alternate the pressure of each inflatable tube at predefined intervals throughout a preselected period of time in accordance with a predetermined schedule. Thus, the present invention provides means of randomly decreasing pressure from various portions of the sleeping human body. 
         [0057]      FIG. 2A  is a perspective view of inflatable tubes in accordance with the present invention. The selectively inflatable mattress  200  comprises tubes  104   a - i.    
         [0058]    The tubes  104   a - i  are substantially described above in relation to  FIGS. 1A-1B . 
         [0059]      FIG. 2A  shows the tubes  104   a - i  as they are positioned within the mattress body  102  in one embodiment of the present invention. In alternative embodiments of the present invention, the tubes  104   a - i  may be irregularly shaped, rather than cylindrical. In still further embodiments, a second set of tubes  104   j - r  may underlay the tubes  104   a -in the mattress body. In some embodiments, the mattress body  102  may comprise multiple rows of tubes  104 , which each row comprises a plurality of tubes  104  oriented in parallel or perpendicular directions with respect to one another. 
         [0060]      FIG. 2B  is a perspective view of hoses and inflatable tubes in accordance with the present invention. The selectively inflatable mattress  250  comprises tubes  104   a - i , and hoses  152   a - i.    
         [0061]    The tubes  104   a - i  and hoses  152   a - i  are substantially described above in relation to  FIGS. 1A-2B . 
         [0062]    In the shown embodiment, the hoses  152   a - i  are coupled to the longitudinal ends of the tubes  104   a - i . In other embodiments of the present invention, the hoses  152   a - i  are connected to the tubes  104   a - i  at intermediate points along the longitudinal axis of the tubes  104   a - i . The hoses  152   a - i , in some embodiments, collectively or individually, split, funnel or fork into one to one hundred secondary hoses, which themselves may be connected to compressors  154 . 
         [0063]      FIG. 3A  is cross-sectional top elevation view of a selectively inflatable mattress in accordance with the present invention. The selectively inflatable mattress  300  comprises a mattress body  102 , and tubes  104   a - r.    
         [0064]    The mattress body  102 , tubes  104   a - r  are substantially described above in relation to  FIGS. 1A-2B . 
         [0065]    The mattress  300  in the shown embodiment comprises two sets of tubes  104 . The first set of tubes  104 , consisting in this embodiment of tubes  104   a - i , laterally traverse only the left lateral side of the mattress body  102 , and are designed to support a mattress user resting on the left side of the mattress body  102 . 
         [0066]    The second set of tubes  104 , consisting in this embodiment of tubes  104   j - r , laterally traverse only the left lateral side of the mattress body  102 , and are designed to support a mattress user resting on the left side of the mattress body  102 . 
         [0067]    The tubes  104   a - i  are connected to a first compressor  154 , while the tubes  104   j - r  are connected to a second compressor  154 . The compressors  154  in this embodiment may be separately configured to perform the functions and operations substantially described above in relation to  FIGS. 1A-2B . 
         [0068]      FIG. 3B  is cross-sectional top elevation view of another embodiment of a selectively inflatable mattress  330  in accordance with the present invention. The selectively inflatable mattress  330  comprises a mattress body  102 , tubes  104   a - i , and hoses  152 - e - i.    
         [0069]    The mattress body  102 , tubes  104   a - i , and hoses  152   e - i  are substantially described above in relation to  FIG. 1A-3A . 
         [0070]    In the shown embodiment, the hoses  152   a - i  travel to the compressor  154  through the mattress body  102 , and are internal to the mattress body  102 . In alternative embodiments, the hoses  152   a - i  are external to the mattress body  102 . In other embodiments, rigid pipe, rather than flexible hoses  152 , interconnect the tubes  104  and compressor  154 . 
         [0071]      FIG. 3C  is cross-sectional top elevation view of another embodiment of a selectively inflatable mattress  360  in accordance with the present invention. The selectively inflatable mattress  360  comprises a mattress body  102 , tubes  104   a - q , a top longitudinal end  362 , a bottom longitudinal end  364 , a left lateral side  366 , and a right lateral side  368 . 
         [0072]    The mattress body  102 , and tubes  104   a - q  are substantially described above in relation to  FIGS. 1A-3C . 
         [0073]    The top longitudinal end  362 , bottom longitudinal end  364 , left lateral side  366 , and right lateral side  368  are also described above in relation to  FIGS. 1A-3C , and shown here for explanatory purposes. 
         [0074]    As shown, in various embodiments of the present invention, the mattress body  102  comprises more than nine tubes  104 . The tubes  104   a - q  in the shown embodiment are of equal volume and diameter, but in various embodiments of the present invention the tubes  104   a - q  may comprise varying volumes and/or diameters. 
         [0075]      FIG. 4A  is cross-sectional side view of a selectively inflatable mattress  400  in accordance with the present invention. The selectively inflatable mattress  400  comprises a mattress body  102 , a tube  104 , and a bladder  402 . 
         [0076]    The mattress body  102  and tube  104  are substantially described above in relation to  FIGS. 1A-3C . 
         [0077]    The mattress body  102  in the shown embodiment comprises a bladder  402 . The bladder  402  comprises an inflatable and deflatable bag that is substantially impermeable to air, made from materials well-known to those of skill in the art. 
         [0078]    The bladder  402  can be filled with and pressurized with ambient air, or other gases, including helium, nitrous oxide, carbon dioxide, and the like. The bladder  402 , like the tubes  104 , is interconnected with a compressor  154  configured to inflate or deflate the bladder in accordance with the instructions of a use. 
         [0079]    The bladder  402  sits above the tubes  104  on the vertical axis within the mattress body, and may span the width and length of the mattress body in some embodiments across the x-axis. In other embodiments, the bladder  402  sites below the tubes  402  and/or spans only a portion of the width and length of the mattress body  102 . 
         [0080]    The bladder  402  provides additional firmness to a region of the surface of the mattress body  102  that overlaps regions of the mattress body  102  whose firmness is substantially affected by the pressure of the tubes  104 . 
         [0081]    The bladder  402  may be positioned to provide lumbar support or thoracic support to users resting on the mattress  400 . 
         [0082]    In some embodiments of the present invention, the bladder  402 , when inflated, changes the contour and shape of a portion of the surface of the mattress body  102 , thus serving as a pillow, back rest, or foot elevator to a user of the mattress  400 . 
         [0083]      FIG. 4B  is cross-sectional side view of another embodiment of a selectively inflatable mattress  430  in accordance with the present invention. The selectively inflatable mattress  430  comprises a mattress body  102 , and tubes  104   a - h.    
         [0084]    The mattress body  102 , and tubes  104   a - h  are substantially described above in relation to  FIGS. 1A-4A . 
         [0085]    The mattress body  102  in the shown embodiment consists of eight tubes  104   a - h  rather than nine tubes  104 . The number of tubes comprised in the mattress body  102  varies, as do their shapes. 
         [0086]      FIG. 4C  is cross-sectional side view of another embodiment of a selectively inflatable mattress  460  in accordance with the present invention. The selectively inflatable mattress  460  comprises a mattress body  102 , and tubes  104   a - h.    
         [0087]    The mattress body  102 , and tubes  104   a - h  are substantially described above in relation to  FIGS. 1A-4B . 
         [0088]    In the shown embodiment, the tubes  104   a - h  are cubic in shape, rather than cylindrical, thus affecting a sharper, more defined surface area of the mattress body  102 . 
         [0089]      FIG. 5  is an elevated perspective view of another embodiment of a selectively inflatable mattress  500  in accordance with the present invention. The selectively inflatable mattress  500  comprises a mattress body  102 , a tube  104 , a bladder  402 , a lower mat  502 , and an upper mat  506 . 
         [0090]    The mattress body  102 , tube  104 , and bladder  402  are substantially described above in relation to  FIGS. 1A-4C . 
         [0091]    The lower mat  502 , and upper mat  506 , are made, in the shown embodiment of, of silicone gel. In other embodiments, the mats  502 ,  506  may comprise other materials, including memory foam and/or bed springs. The mats  502 ,  506  overlay and underlay the mattress body  102  respectively. 
         [0092]    The mats  502 ,  506  may comprise, in various embodiments, viscoelastic gel well-known to those of skill in the art, and may vary in thickness from one millimeter to more than four feet. 
         [0093]    In various embodiments of the present invention, the mats  502 ,  506  are added to the surface of the mattress body  102  to eliminate bedsores and change pressure points agitating a user in the mats&#39;  502 ,  506  absence. 
         [0094]    In various embodiments, the bladder  402  is connected to the upper mat  506 , and deforms the upper mat&#39;s  506  planar surface when the bladder  402  is inflated. 
         [0095]    The mats  502 ,  506  may be inflatable, or comprise bed springs and/or memory foam in various embodiments. The mats  502 ,  506  may be removable, and/or coupled to the mattress body  102  with Velcro® or through other means well-known to those of skill in the art. 
         [0096]    The mattress body  102  in the shown embodiment comprises only a single tube  104 , which is ovally-shaped on its cross-section. In various embodiments, the mattress  500  comprises a single tube  104  running laterally or longitudinally across through the mattress body  102 . The ovally-shaped tube  104  provides more firmness to a more defined region of the mattress body  102  surface as the top surface of the tube  104  drops off more suddenly towards its edges than does the top surface of cylindrically-shaped tubes  104 . Thus, the present invention teaches a means of sharpening the affected region of the surface of the mattress body  102 . 
         [0097]    In various embodiments, the mattress  500  may be configured to allow a user to add or remove mats  502 ,  506  from the surface of the mattress body  102 , thus affecting the vertical proximity of the tube  104  to the mattress body surface  102 , and thus further sharpening the edges of the region affected by the pressure of the tube  104 . 
         [0098]    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.