Abstract:
The present invention provides a body support assembly comprising a layer having a passage, a pump positioned to create a flow of fluid through the passage, a sensor that detects a parameter and produces a signal, and a controller coupled to the sensor and programmed to control the flow of fluid based on the signal. Preferably, the layer comprises visco-elastic foam. In one embodiment, the parameter corresponds with a firmness of the layer (e.g., a temperature of the layer). A heat exchanger can be used to alter (e.g., heat or cool) a temperature of the fluid. The present invention further provides a method of controlling a firmness of a body support comprising sensing a sensed value of a parameter (e.g., temperature) of the body support, establishing a desired value of the parameter, comparing the sensed parameter to the desired value, and adjusting the parameter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 13,141,558, filed Aug. 17, 2011 which claims priority to U.S. Provisional Patent App. No. 61/139,971, filed Dec. 22, 2008, the entire contents of which are herein incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    Visco-elastic foam is sometimes used to form mattresses and other body supports, has the ability to conform to a user&#39;s body, and can provide pressure relief for the user&#39;s body. Many types of visco-elastic foam have a glass transition temperature at least partially within the range of temperatures at which a room can be or is likely to be maintained (e.g., 10-30.degree. C.). Therefore, for such visco-elastic foams, the temperature of the visco-elastic foam at least partially determines the firmness of the body support. As the temperature of the body support&#39;s environment increases (such as by an increase in room temperature and/or by transmission of heat to the body support from a user&#39;s body), the firmness of the body support can be reduced. Alternatively, as the temperature of the body support&#39;s environment decreases (such as by a decrease in room temperature and/or reduction in the amount of heat provided to the body support by a user), the firmness of the body support can be increased. 
         [0003]    A particularly desirable feature for many body supports is the ability to adjust the hardness of the body support. However, the ability to control the firmness of body supports comprising visco-elastic foam has heretofore been limited. Body supports comprising visco-elastic foam having a hardness that can be adjusted by a user would be welcome additions to the art. 
       SUMMARY 
       [0004]    The present invention provides a body support assembly comprising a layer (e.g., first and second layers) having a passage (e.g., between the first and second layers), a pump positioned to create a flow of fluid through the passage, a sensor that detects a parameter and produces a signal, and a controller coupled to the sensor and programmed to control the flow of fluid based on the signal. Preferably, the layer comprises visco-elastic foam. In one embodiment, the parameter corresponds with a firmness of the layer (e.g., a temperature of the layer). 
         [0005]    If desired, the body support assembly can further include a heat exchanger for altering (e.g., heating or cooling) a temperature of the fluid. Preferably, the body support has at least two areas, and each area has a sensor and a passage through which fluid can flow, and the controller can control the fluid through each passage to separately control the parameter of the different areas. In one embodiment, the body support assembly further includes a user interface coupled to the controller and adapted to select a desired parameter of the body support assembly. 
         [0006]    The present invention further provides a method of controlling a firmness of a body support. The method includes sensing a sensed value of a parameter (e.g., temperature) of the body support (the parameter corresponding with the firmness of the body support), establishing a desired value of the parameter, comparing the sensed parameter to the desired value, and adjusting the parameter such that the sensed value moves toward the desired value. In one embodiment, the body support assembly further includes a user interface, and establishing comprises entering a desired firmness into the user interface. Preferably, establishing further includes determining the desired value based on the desired firmness. 
         [0007]    In another embodiment, adjusting comprises changing a temperature of the body support. For example, changing a temperature of the body support can include changing a temperature of a fluid moving through the body support. 
         [0008]    In some embodiments, the present invention provides a body support comprising visco-elastic foam, a fluid system including a conduit in heat-transfer relationship with the visco-elastic foam, a heat exchanger in fluid communication with the conduit, and a pump operable to pump a fluid through the at least one conduit and heat exchanger to transfer heat to or from the visco-elastic foam. The body support can also include one or more sensors positioned to measure the temperature of the visco-elastic polyurethane foam in one or more locations in or on the body support, and a controller coupled to the fluid system and sensor(s) to receive the temperatures detected by the sensor(s) and to change the operation of the pump (i.e., change the pump speed and/or turn the pump on or off) and/or heat exchanger (i.e., heating or cooling the fluid passing through the heat exchanger) based upon the temperatures detected by the sensor(s). In this manner, the firmness of the body support can be adjusted in response to pumping the heated or cooled fluid through the conduit and conducting thermal energy either to or from the visco-elastic foam. 
         [0009]    Other aspects of the present invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a plan sectional view of a mattress according to an embodiment of the present invention. 
           [0011]      FIG. 2  is a sectional view of the mattress in  FIG. 1 . 
           [0012]      FIG. 3  is a schematic diagram of the mattress illustrated in  FIG. 1 , showing a controller in communication with a fluid system and a sensor of the mattress. 
       
    
    
       [0013]    Before any embodiments of the present invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Also, terms such as “first”, “second”, and “third” are used herein and in the appended claims for purposes of description and are not intended to indicate or imply relative importance or significance unless otherwise specified. The term “first” does not necessarily refer to the top most layer, rather, it refers to the first of a plurality, without indicating a particular location or position. 
         [0014]    The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
       DETAILED DESCRIPTION 
       [0015]      FIGS. 1-3  illustrate a body support  10  according to an embodiment of the present invention. In the illustrated embodiment, the body support  10  is a mattress. The illustrated body support  10  includes two layers of foam: a first layer  14  and a second layer  18  positioned above the first layer  14 . In the illustrated embodiment, the first layer  14  comprises foam, such as a latex foam, reticulated or non-reticulated non-visco-elastic foam or visco-elastic foam (sometimes referred to as “memory foam” or “low resilience foam”), any polyurethane high-resilience (HR) foam, any expanded polymer (e.g., expanded ethylene vinyl acetate, polypropylene, polystyrene, or polyethylene), and the like, whereas the second layer  18  comprises reticulated or non-reticulated visco-elastic foam. 
         [0016]    As described above, visco-elastic foam has unique low-resilience, slow-recovery, body-containing, and pressure distributing properties that are inherently attractive for use in a wide variety of body support applications, including mattresses such as that shown in  FIGS. 1-3 . The visco-elastic foam described herein (e.g., whether for use in the first layer  14  or second layer  18  of the illustrated embodiment) has a hardness of at least about 20 N and no greater than about 80 N for desirable softness and body-conforming qualities. In other embodiments, the visco-elastic foam has a hardness of at least about 30 N and no greater than about 70 N for this purpose. In still other embodiments, a viscoelastic foam hardness of at least about 40 N and no greater than about 60 N is utilized. Unless otherwise specified, the hardness of a material referred to herein is measured by exerting pressure from a plate against a sample of the material to a compression of 40% of an original thickness of the material at approximately room temperature (e.g., 21-23 Degrees Celsius), wherein the 40% compression is held for a set period of time, following the International Organization of Standardization (ISO) 2439 hardness measuring standard. 
         [0017]    The visco-elastic foam described herein can also have a density providing a relatively high degree of material durability. The density of the visco-elastic foam can also impact other characteristics of the foam, such as the manner in which the visco-elastic foam responds to pressure, and the feel of the foam. In some embodiments, the visco-elastic foam has a density of no less than about 30 kg/m.sup.3 and no greater than about 150 kg/m.sup.3. In other embodiments, a visco-elastic foam having a density of at least about 40 kg/m.sup.3 and no greater than about 135 kg/m.sup.3 is utilized. In still other embodiments, visco-elastic foam having a density of at least about 50 kg/m.sup.3 and no greater than about 120 kg/m.sup.3 is utilized. 
         [0018]    The visco-elastic foam used in the various body support embodiments described and/or illustrated herein can be reticulated or non-reticulated visco-elastic foam. In this regard, reticulated visco-elastic foam has characteristics that are also well suited for use in the body support  10 , including the enhanced ability to permit fluid movement through the reticulated visco-elastic foam, thereby providing enhanced air and/or heat movement within, through, and away from the reticulated visco-elastic foam. Reticulated foam (visco-elastic or otherwise) is a cellular foam structure in which the cells of the foam are essentially skeletal. In other words, the cells of the reticulated foam are each defined by a plurality of apertured windows surrounded by cell struts. The cell windows of reticulated foam can be entirely gone (leaving only the cell struts) or substantially gone. In some embodiments, the foam is considered “reticulated” if at least 50% of the windows of the cells are missing (i.e., windows having apertures therethrough, or windows that are completely missing and therefore leaving only the cell struts). Such structures can be created by destruction or other removal of cell window material, or preventing the complete formation of cell windows during the manufacturing process of the foam. 
         [0019]    With continued reference to the illustrated embodiment of  FIGS. 1-3 , the second layer  18  of visco-elastic foam can be positioned above the first layer  14  without being secured thereto. However, in other embodiments, the first and second layers  14 ,  18  are secured to one another by adhesive or cohesive bonding material, by being bonded together during formation of the first and second layers  14 ,  18 , by tape, hook and loop fastener material, conventional fasteners, stitches extending at least partially though the first and second layers  14 ,  18 , or in any other suitable manner. In some embodiments, the body support  10  is constructed of fewer or more than two layers of visco-elastic foam. 
         [0020]    With reference to  FIGS. 1 and 2 , each of the first and second layers  14 ,  18  can be substantially flat bodies having substantially planar top and bottom surfaces  26 ,  30 ,  34 ,  38 . However, in other embodiments, one or more of the top and bottom surfaces  26 ,  30 ,  34 ,  38  of either or both first and second layers  14 ,  18  can be non-planar, including without limitation surfaces having ribs, bumps, and other protrusions of any shape and size, surfaces having grooves and other apertures that extend partially or fully through the respective layer  14 ,  18 , and the like. Also, depending at least in part upon the application of the body support  10  (i.e., the product defined by the body support  10  or in which the body support  10  is employed), either or both of the first and second layers  14 ,  18  can have shapes that are not flat. By way of example only, either or both layers  14 ,  18  can be generally wedge-shaped, can have a concave or convex cross-sectional shape, can have a combination of convex and concave shapes, can have a stepped, faceted, or other shape, can have a complex or irregular shape, and/or can have any other shape desired. 
         [0021]    One of the properties of visco-elastic foam is glass transition, The glass transition temperature of visco-elastic foam can impact the degree of firmness of the body support  10  (e.g., by changing the firmness of the second layer  18 , and also by changing the firmness of the first layer  14  and other layers in those embodiments in which the first layer  14  and any other layers comprise visco-elastic foam). In some embodiments of the present invention, the glass transition temperature of the visco-elastic foam falls at least partially within the range of about 10.degree. C. and about 30.degree. C. In the illustrated embodiment, the second layer  18  changes in firmness through a range of temperatures of the second layer  18 . The firmness of the body support  10  can thereby be adjusted by changing the temperature of the second layer  18 . In other words, the body support  10  has a variable firmness that is controlled by the temperature of the visco-elastic foam in the second layer  18  (and in any other layer of the body support  10  comprising visco-elastic foam, in some embodiments). 
         [0022]    As shown in  FIGS. 1 and 2 , the body support  10  includes a fluid system  42  utilizing a fluid to heat and/or cool the visco-elastic foam within the body support  10 . The fluid system  42  can include a conduit  46  (described in greater detail below), and a pump  50  for moving fluid within the conduit  46 . In some embodiments, the fluid is water. In other embodiments, fluids selected for use in the fluid system  42  include other fluids having relatively high heating and cooling capabilities, such as anti-freeze fluid, glycol, oil, and any combination thereof (whether used in conjunction with water or otherwise). 
         [0023]    The conduit  46  extends through the body support  10  in a manner in which the conduit  46  extends across all areas of the body support  10  to enable fluid within the conduit  46  to cool or heat the visco-elastic foam within the body support  10 . Any conduit shape and configuration can be used for this purpose. By way of example, the conduit shape and configuration in the illustrated embodiment is substantially serpentine, such that portions of the conduit  46 A are substantially straight, extend across the body support  10 , and are joined to one another at opposite ends by other portions  46 B of the conduit  46  that can be bent, curved, or otherwise shaped for this purpose. The conduit  46  can be any type of hose, tube, pipe, or other structure capable of conveying fluid through the body support  10 . Also, the conduit can be made of a thermally-conducting material, such as copper, stainless steel, aluminum, and other metal, thermally conductive polymer, and the like). 
         [0024]    In some embodiments, the conduit  46  is defined by a single continuous element (e.g., pipe, tube, hose), whereas in other embodiments, the conduit  46  is defined by multiple elements connected together in any manner. Although a single serpentine run of the conduit  46  is shown in  FIGS. 2 and 3 , the conduit  46  can extend in a number of other manners, some of which define two or more different flow paths for fluid through the body support  10 . For example, the conduit  46  can define a serpentine shape through the body support extending in a pattern oriented at 90.degree. to that shown in  FIG. 1 , can define a grid within the body support  10 , and the like. In any of the embodiments described and/or illustrated herein, the conduit  46  can include one or more manifolds from which multiple portions of the conduit  46  extend to define multiple discrete or non-discrete flow paths for the fluid. For example, the conduit  46  can comprise two manifolds (e.g., inlet and outlet) connected together by parallel runs of the conduit  46  extending between and fluidly connecting the manifolds in a single-pass or multiple-pass flow configuration. One or more baffles in either or both manifolds or in other locations in the conduit  46  can be used to define the number of passes the fluid must make between the manifolds. 
         [0025]    With reference now to  FIG. 2  of the illustrated embodiment, the conduit  46  of the fluid system  42  is positioned between the first and second layers  14 ,  18  such that the conduit  46  rests against and indents the surfaces  26 ,  38  of the first and second layers  14 ,  18 , respectively. Alternatively, the facing surfaces  26 ,  38  of the first and/or second layers  14 ,  18  can be shaped to at least partially receive the conduit  46 , such as by having channels shaped and dimensioned to receive the conduit  46 . In either case, the first and second layers  14 ,  18  can cooperate to surround the cross-sectional shape of the conduit  46 . In some embodiments, the conduit  46  is recessed within the second visco-elastic foam layer  18  to a greater extent than the first layer  14 , or is only recessed within the second visco-elastic foam layer  18 . Such a relationship between the conduit  46  and the second visco-elastic foam layer  18  can enhance the ability of the conduit  46  to heat or cool the second visco-elastic foam layer  18 , thereby enhancing the ability of the conduit  46  to change the firmness of the second visco-elastic foam layer  18 . 
         [0026]    With reference now to  FIGS. 1 and 3 , the conduit  46  is coupled to and fluidly communicates with the pump  50  such that the conduit  46  and the pump  50  form a closed fluid circuit. In the illustrated embodiment, the pump  50  is positioned outside of the layers  14 ,  18  of the body support  10 . However, in other embodiments, the pump  50  can be recessed within or received completely within either or both of the layers  14 ,  18  (e.g., received within a recess in the lower surface  30  or side surface of the first layer  14 ). 
         [0027]    In the illustrated embodiment, the pump  50  is connected to a heat exchanger  52  that heats or cools the fluid moved by the pump  50  to increase and decrease, respectively, the temperature of the second layer  18 . Fluid can be heated by the heat exchanger  52  in any number of manners, including without limitation by one or more electric heating elements. Alternatively, fluid can be cooled by the heat exchanger  52  by a fan directing cooling airflow past a number of heat exchanger tubes through which the fluid is moved, by Peltier cooling elements, and the like. Embodiments of the body support  10  can be capable only of heating the fluid pumped by the pump  50 , capable only of cooling the fluid pumped by the pump  50 , or can be capable of both heating and cooling the fluid pumped by the pump  50  (i.e., the embodiment of  FIGS. 1-3 ). 
         [0028]    With continued reference to  FIGS. 1-3 , when the temperature of the fluid is greater than the temperature of the second layer  18 , thermal energy is conducted from the fluid, through the conduit  46  and to the second layer  18  to increase the temperature and decrease the firmness of the second layer  18 . Similarly, when the temperature of the fluid is less than the temperature of the second layer  18 , thermal energy is conducted from the second layer  18 , through the conduit  46  and to the fluid to decrease the temperature and increase the firmness of the second layer  18 . In other words, by increasing and decreasing the temperature of the second layer  18 , the fluid system  42  decreases and increases, respectively, the degree of firmness of the body support  10 . 
         [0029]    The pump  50  can be powered by, for example, a portable power source, such as a battery (not shown), or by any other power source (e.g., household or building electric power circuit). The battery can be separate from the pump  50  and heat exchanger  52 , or can be included in the same housing or frame as the pump  50  and/or heat exchanger  52 . In this regard, the battery can be embedded into any portion of the body support  10 , if desired. 
         [0030]    As shown in  FIG. 3 , the body support  10  of the illustrated embodiment also includes a sensor  54  and a controller  58  in communication with the sensor  54 . The controller  58  can be powered by the same power source as the fluid system  42  or any other power source. The controller  58  in the illustrated embodiment is also coupled to the pump  50  and heat exchanger  52 . In some embodiments, a single sensor  54  is used; although in other embodiments, the body support  10  can include multiple sensors  54 . The sensor(s) can be positioned on or in the body support  10  to enable measurement of the temperature (and therefore the firmness) of the visco-elastic, foam of the body support  10 . For example, one or more sensors  54  can be located on the top surface  34  of the second layer  18  or can be recessed within or embedded beneath the top surface  34  of the second layer  18  at any location along the length and width of the body support  10 . In this manner, the sensor(s)  54  can detect the temperature of the second layer  18  at such locations, and can provide such temperature information to the controller  58 . In these and other embodiments, one or more sensor(s)  54  are positioned outside of the body support  10  and instead detect the temperature of the environment around the body support  10  (thereby indirectly enabling an estimate to be made of the temperature of the second layer  18  or of any other layer of the body support  10 ). 
         [0031]    As just described, the sensor(s)  54  in the illustrated embodiment are positioned to sense the temperature of the second layer  18 , and can provide that information to the controller  58 . In some embodiments, one or more additional sensors (not shown) can be used to sense, for example, pressure, movement, moisture, or other parameters to be provided to the controller  58 . Temperature or other data can be transmitted from the sensor(s)  54  to the controller  58  via a hardwired connection, or via a wireless connection (in which case the sensor(s)  54  can each be connected to one or more suitable transmitters, and the controller  58  can be connected to a suitable receiver for receiving the sensor data). 
         [0032]    In some embodiments, the controller  58  is embedded into the body support  10 , away from the resting position of the user&#39;s body upon the body support  10 , and can share the same housing or frame as the pump  50 , battery, and/or heat exchanger  52  (whether embedded within the body support  10  as described above, or otherwise). For example, the controller  58  can be located within a recess in the first layer  14 , such as in a side surface of the first layer  14 . 
         [0033]    The controller  58  can be a programmable or non-programmable microprocessor capable of receiving temperature data from the sensor(s)  54  of the body support  10 , processing the temperature data, and responding by changing operation of the pump  50  and/or heat exchanger  52 . The controller  58  can be electrically coupled to a user interface (not shown) having one or more user-manipulatable controls, such as buttons, dials, switches, a touch screen, and the like. These controls can enable a user of the body support  10  to input desired firmness settings and/or commands to change operation of the pump  50  and/or heat exchangers  52 , and in some embodiments can display body support information to the user (e.g., body support firmness, body support temperature, and the like). 
         [0034]    The user interface can he on a housing shared with the pump  50 , heat exchangers  52 , and/or controller  58 , or can be on another housing separate from the pump  50 , heat exchangers  52 , and/or controller  58 . For example, the user interface can be defined on a hand-held remote in communication with the controller  58  via a wired connection (e.g., tether) or via a wireless connection (using suitable transmitters and receivers coupled to the controller  58  and user interface). 
         [0035]    The controller  58  can receive inputs from a user via the user interface to adjust the firmness of the body support  10  (by changing the temperature of the visco-elastic foam of the body support  10 ). This adjustment can be made by the controller speeding or slowing operation of the pump, by stopping or starting the pump, by providing more or less electrical energy to electric heating and/or cooling elements of the heat exchanger  52 , by increasing or decreasing the speed of a fan cooling the heat exchanger  52 , by turning such a fan on or off, and the like (depending at least in part upon the type of heat exchanger used to heat and/or cool the fluid pumped through the body support  10 ). 
         [0036]    With continued reference to the illustrated embodiment, a user can adjust or tune the temperature of the visco-elastic foam in the body support  10  to a degree that is proportional to a desired mattress firmness. In operation, the sensor(s)  54  sense the temperature of the body support  10  (e.g., the visco-elastic foam layer  18 ), and provides the sensed temperature to the controller  58 . The controller can compare the sensed temperature to a preferred or desired temperature for the body support  10  (e.g., the second layer  18 ) input by the user. The controller  58  can thereafter automatically adjust the temperature of the body support  10  by controlling the pump  50 , heat exchanger  52 , or fan as described above until the measured temperature is the same as the desired temperature. For example, if the measured temperature is cooler than the desired temperature, then the controller  58  can increase the amount of heating (thermal) energy delivered by the heat exchanger  52  to the fluid being pumped. The heated fluid is pumped through the conduit  46 , and the thermal energy in the fluid is conducted through the conduit  46  to the visco-elastic foam layer  18 . As another example, if the measured temperature is warmer than the desired temperature, then the controller  58  can decrease the amount of heating (thermal) energy delivered by the heat exchanger  52  to the fluid being pumped, or can cool the fluid. The fluid is pumped through the conduit  46 , and the thermal energy in the visco-elastic foam is conducted through the conduit  46  to the fluid to decrease the temperature of the visco-elastic foam layer  18 . 
         [0037]    In some embodiments, the fluid system  42  is automatically activated (i.e., the pump  50  and/or heat exchanger  52  is turned on or is placed in a state in which it can be activated by the controller  58 ) when a user is sensed to have rested upon the body support  10 , such as by a pressure sensor as described above. Alternatively, the fluid system  42  can be activated by the user via the user interface described above. In any case, if the temperature sensed by the sensor(s)  54  indicate that the firmness of the body support is too high or too low, the controller  58  can automatically adjust the pump  50  and/or heat exchanger  52  accordingly (as also described above) to provide heat to or draw heat away from the body support  10  in order to lower or raise the firmness of the visco-elastic foam, respectively. In some embodiments, the controller  58  can be programmed to activate the fluid system  42  at a particular time of day, thereby readying the body support  10  for the user in advance of use. 
         [0038]    In some embodiments, the controller  58  can determine when the programmed parameter (e.g., layer temperature, corresponding to layer firmness) has been reached based on data received from the sensor(s)  54 . Furthermore, the controller  58  can automatically change operation of the fluid system  42  (e.g., turning the pump off, turning off the heat exchanger  52 , and the like) in response to reaching the programmed, desired and/or preferred parameter. 
         [0039]    In some embodiments, the controller  58  can regulate the temperature of one or more visco-elastic foam layers for multiple users (i.e., multiple temperature settings) and/or can regulate the temperature of one or more areas of a visco-elastic foam layer for the same user. For example, the body support  10  can be a mattress having two adjacent areas upon which two users can respectively lie. One of the two areas can be programmed to a particular firmness, While the other area can be programmed to a different firmness. In such embodiments, two different conduits  46  can extend through or otherwise be in heat exchange relationship with visco-elastic foam in the two different areas of the body support  10 , and can be provided with fluid at different temperatures. In this regard, the two different conduits  46  can define separate or substantially separate closed fluid circuits, each of which operate in any of the same manners described above in connection with the embodiment of  FIGS. 1-3  (i.e., with dedicated sensor(s)  54 ). Alternatively, the two different conduits  46  can share the same fluid, which can be independently moved through the respective conduits  46  for cooling and/or heating using the same pump  50  (with appropriate switching valve(s) in fluid communication therewith and under control of the controller  58 ) or using dedicated pumps  50 . In any case, fluid flowing to each of the two different areas of the body support  10  can be independently heated and/or cooled using dedicated heat exchangers  52  separately controlled by the controller  58 . 
         [0040]    The features of the system described above for independently heating and/or cooling different areas of a body support  10  on which two different users lie apply equally to the control of two or more different areas of a body support  10  for the same user (e.g., head, torso, and leg areas of the body support  10 ). In such cases, any number of different areas of the body support  10  can have dedicated conduits  46  for moving fluid under different temperatures (i.e., heated, cooled and/or pumped independently with respect to the fluids in the other conduits  46 ) through the different body support areas. 
         [0041]    In some embodiments, the fluid system  42  is removable from the body support  10 . Also, in some embodiments, multiple layers of conduits  46  passing through the same or different layers of visco-elastic foam in the body support  10  can be utilized to increase and/or decrease the temperature and resulting firmness of one or more layers of visco-elastic foam at different depths of the body support  10 . 
         [0042]    In the illustrated embodiment of  FIGS. 1-3 , the conduit  46  of the body support  10  is located between two layers  14 ,  18  of the body support  10 , and can be recessed within either layer  14 ,  18  as desired. In other embodiments, the conduit  46  can be partially or entirely embedded within a layer of the body support  10 , such as entirely or partially within the visco-elastic second layer  18  of the illustrated body support  10 . In such embodiments, the layer (e.g., layer  18 ) can be molded (e.g., injection molded, spray molded, and the like) as a single layer, with the conduit  46  embedded in the molded layer during manufacture. 
         [0043]    The body support  10  illustrated in  FIGS. 1-3  is presented in the form of a mattress. However, it will be appreciated that the features of the body support  10  described above are applicable to any other type of body support having any size and shape. By way of example only any of the features described above are equally applicable to mattress toppers, overlays, futons, sleeper sofas, seat cushions, seat backs, and any other element used to support or cushion any part or all of a human or animal body. Accordingly, as used herein, the term “body support” is intended to refer to any and all of such elements (in addition to mattresses). 
         [0044]    Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention described. 
         [0045]    Various features and advantages of the invention are set forth in the following claims.