Abstract:
A heat exchange assembly includes a heat exchanger panel upon which a person is supportable. The heat exchanger panel includes at least two interconnected layers of polymer material and at least one channel defined between the layers through which a heat exchange fluid may be circulated. The assembly further includes a heat pump operable to circulate the heat exchange fluid through the channel.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to heat exchange devices, and more particularly to infant warmers. 
       BACKGROUND OF THE INVENTION 
       [0002]    Infant warmers are commonly used in hospitals to maintain an infant at a proper temperature. Conventional infant warmers often employ a radiant heater or lamp that radiates infrared heat energy upon the infant. A temperature sensor is typically placed on the infant to provide control feedback to the radiant heater. This type of conventional infant warmer has several drawbacks. Because the heater is positioned above the infant, it can obstruct access to the infant. In addition, if the temperature sensor is forgotten or improperly positioned, the heater may overheat the infant. 
       SUMMARY OF THE INVENTION 
       [0003]    The invention provides, in one aspect, a heat exchange assembly including a heat exchanger panel upon which a person is supportable. The heat exchanger panel includes at least two interconnected layers of polymer material and at least one channel defined between the layers through which a heat exchange fluid may be circulated. The heat exchange assembly further includes a heat pump operable to circulate the heat exchange fluid through the channel. 
         [0004]    The invention provides, in another aspect, a heat exchanger panel upon which a person is supportable. The heat exchanger panel includes at least two interconnected layers of polymer material and at least one channel defined between the layers through which a heat exchange fluid may be circulated to heat or cool the person. 
         [0005]    Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a perspective view of an infant warmer in accordance with an embodiment of the invention. 
           [0007]      FIG. 2  is an exploded view of a portion of the infant warmer of  FIG. 1 , illustrating a heat exchanger panel. 
           [0008]      FIG. 3  is a perspective view of the heat exchanger panel of  FIG. 2  in communication with a heat pump of the infant warmer of  FIG. 1 . 
           [0009]      FIG. 4  is an exploded view of the heat exchanger panel of  FIG. 2 . 
           [0010]      FIG. 5  is an enlarged perspective view of a portion of the heat exchanger panel of  FIG. 2 . 
       
    
    
       [0011]    Before any embodiments of the 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. 
       DETAILED DESCRIPTION 
       [0012]      FIG. 1  illustrates an infant warmer  10  including a base  14 , a support portion  18 , and a warming platform  22  coupled to the support portion  18 . In the illustrated embodiment, the warming platform  22  is cantilevered from the support portion  18  so that the warming platform  22  can be positioned over a hospital bed, for example. In other embodiments, the warming platform  22  can be supported in any other suitable fashion. Two rear wheels  26  and a recessed front caster  28  are coupled to the base  14  to facilitate maneuvering the infant warmer  10 . 
         [0013]    With reference to  FIG. 2 , the warming platform  22  includes a housing  30  and a heat exchanger panel  34 , on which a person or infant is supportable, supported by the housing  30 . Best illustrated in  FIG. 5 , the heat exchanger panel  34  is made of first and second interconnected sheets  38 ,  42  of a heat-shrinkable polymer material. The interconnected sheets  38 ,  42  may define a self-corrugating polymer panel such as those described in U.S. Patent Application Publication Nos. 2014/0087145, 2014/0087146, and 2014/0087147, the entire contents of all of which are incorporated herein by reference. 
         [0014]    Before assembling the heat exchanger panel  34 , each of the sheets  38 ,  42  is uniaxially stretched to impart direction or orientation in the polymer chains. The sheets  38 ,  42  are oriented so that the stretched direction of the first sheet  38  is generally perpendicular to the stretched direction of the second sheet  42 . A radio frequency (RF) or other suitable welding process is used to create weld spots  46  that permanently bond the sheets  38 ,  42  at evenly-spaced intervals. The sheets  38 ,  42  are then heated, causing them to shrink along orthogonal axes. This creates undulations  50  in each of the sheets  38 ,  42  between adjacent weld spots  46 . 
         [0015]    With continued reference to  FIG. 5 , the undulations  50  in the first sheet  38  define a first plurality of channels  54  extending in a first direction  58 , and the undulations  50  in the second sheet  42  define a second plurality of channels  66  extending in a second direction  70  that is orthogonal to the first direction  58 . In the illustrated embodiment, the first and second channels  54 ,  66  are separated in a third direction  78 , orthogonal to the first and second directions  58 ,  70 , by a third sheet  82 . Unlike the first and second sheets  38 ,  42 , the third sheet  82  is not uniaxially stretched and therefore remains generally flat during the heat shrinking process described above. 
         [0016]    With reference to  FIG. 3 , the infant warmer  10  includes a digitally controlled heat pump  86  for circulating a heat exchange fluid (e.g., water) throughout the heat exchanger panel  34 , thereby warming the heat exchanger panel  34  to a desired temperature set point. In the illustrated embodiment, the temperature set point may be between about 97.7 and about 99.5 degrees Fahrenheit (i.e. the body temperature of an infant). In other embodiments, the temperature set point may be any desired temperature below the glass transition temperature of the polymer sheets  38 ,  42 ,  82  and within the performance capabilities of the heat pump  86 . In some embodiments, the heat pump  86  may be configured to remove heat from the heat exchanger panel  34  to provide a cooling effect. 
         [0017]    Referring to  FIGS. 3-5 , the heat pump  86  fluidly communicates with the heat exchanger panel  34  via a supply line  90  and a return line  94  ( FIG. 3 ). The supply line  90  and the return line  94  communicate with the respective first and second pluralities of channels  54 ,  66  to route the heat exchange fluid through the panel  34 . In the illustrated embodiment, the supply line  90  feeds into a frame  98  surrounding the heat exchanger panel  34 . 
         [0018]    Once inside the frame  98 , the fluid enters a first  66   a  of the channels  66  and flows through the channel  66   a  in the direction of arrow  70  ( FIG. 5 ). The fluid is prevented from entering the adjacent channels  66  by a gasket  102   a  ( FIG. 4 ) that seals against an interior of the frame  98 . Accordingly, all of the supplied fluid enters the first channel  66   a.  When the fluid reaches the end of the panel  34  opposite the supply line  90 , it exits the first channel  66   a  and enters the open end of a second channel  66   b  adjacent the first channel  66   a,  generally following the flow path illustrated by arrow  71  in  FIG. 5 . A gasket  102   b  seals against the interior of the frame  98  to prevent the fluid from flowing beyond the entrance to the second channel  66   b.  Upon entering the second channel  66   b,  the fluid flows in the direction of arrow  72 . The fluid continues to flow through the remaining channels  66  in series, encountering additional gaskets  102  such that the fluid flows back and forth through the channels  66  to create a serpentine flow pattern. Plugs  104  cooperate with the undulations  58  between adjacent channels  66  to prevent the fluid from leaking out of the heat exchanger panel  34 . 
         [0019]    Once the fluid exits the last of the channels  66 , it is directed into a first  54   a  ( FIG. 5 ) of the channels  54  by a gasket  102   c  ( FIG. 4 ) such that the fluid flows through the channel  54   a  in the direction of arrow  58  ( FIG. 5 ). When the fluid reaches the end of the panel  34 , it exits the first channel  54   a  and enters the open end of a second channel  54   b  adjacent the first channel  54   a,  generally following the flow path illustrated by arrow  59  in  FIG. 5 . A gasket  102   d  seals against the interior of the frame  98  to prevent the fluid from flowing beyond the entrance to the second channel  54   b.  Upon entering the second channel  54   b,  the fluid flows in the direction of arrow  60 . The fluid continues to flow through the remaining channels  54  in series, encountering additional gaskets  102  such that the fluid flows back and forth through the channels  54  to create a serpentine flow pattern. The fluid is ultimately drawn out of the panel  34  through the return line  94  ( FIG. 3 ). 
         [0020]    In other embodiments, the heat exchanger panel  34  may be configured to have any other fluid flow pattern. For example, the frame  98  may function as a manifold to supply the heat exchange fluid to each of the channels  66  in parallel. Because the second channels  66  are orthogonal to the first channels  54 , the flow of supply and return fluid forms a crossing pattern. 
         [0021]    With reference again to  FIG. 2 , the illustrated infant warmer  10  includes a comfort layer or pad  106  positioned on top of the heat exchanger panel  34  to provide a relatively soft and compliant surface on which to support the infant. The pad  106  can be made of a thermally conductive fabric or foam to allow heat transfer between the infant and the heat exchanger panel  34 . One or more sensors  110  may be incorporated in the pad for detecting the temperature of the infant supported thereon. This temperature data can be provided to the heat pump  86  for varying the temperature of the circulated heated fluid in accordance with the desired temperature set point. 
         [0022]    In operation, an infant to be warmed is placed on the pad  106  on top of the heat exchanger panel  34 . The heat pump  86  is then activated to begin supplying heated fluid (e.g., water) to the heat exchanger panel  34 . The heated fluid is pumped through the supply line  90  and circulates through the channels  66 ,  54 . Heat is transferred from the heated fluid flowing through the panel  34 , through the pad  106 , and to the infant. The fluid loses heat during this process and returns to the heat pump  86  through the return line  94  to be reheated. The one or more sensors  110  in the pad provide feedback to the heat pump  86  in order to reliably heat the infant to the desired temperature set point. 
         [0023]    Although the heat exchanger panel  34  is described herein as part of an infant warmer  10 , the heat exchanger panel  34  may be adapted for a variety of other applications. For example, the heat exchanger panel  34  may be incorporated into a mattress, automotive seat cushion, or any other application where controlled heating or cooling is desired. 
         [0024]    Various features of the invention are set forth in the following claims.