Abstract:
An apparatus for warming a person includes an inflatable cover having two inlet ports and a plug removably received in one of the ports. With the plug received in the one port, the cover can be inflated by way of the port without the plug.

Description:
PRIORITY  
       [0001]     This is a divisional of U.S. patent application Ser. No. 09/815,877, which is a continuation of U.S. patent application Ser. No. 09/496,599, filed Feb. 2, 2000, now U.S. Pat. No. 6,228,107, which is a continuation of U.S. patent application Ser. No. 09/368,206, filed Aug. 4, 1999, now U.S. Pat. No. 6,241,755, which is a continuation of U.S. patent application Ser. No. 08/624,101, now U.S. Pat. No. 5,997,572. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to devices for warming a patient during a medical procedure, and more particularly, to an apparatus for restricting air flow through an inlet port in an inflatable thermal blanket used to warm a patient during a medical procedure.  
         [0004]     2. Description of the Related Art  
         [0005]     Hypothermia, a condition in which a person&#39;s body temperature drops below normal, presents serious potential consequences to a patient. Studies have shown that hypothermia occurs in nearly 75 percent of all patients who undergo surgical procedures. Based on recent numbers, this means that 14 million patients a year in the United States alone suffer from hypothermia during surgical procedures. Hypothermia during surgery may be caused by anesthesia, air conditioning within the operating room, infusion of cold blood, LV solutions, and/or irrigation fluids, in addition to other factors.  
         [0006]     One well known method for reducing hypothermia during surgical procedures is to place an inflatable thermal blanket over a patient during a surgical procedure. The thermal blanket is inflated with a warmed airstream, exhausting warmed inflating air onto the patient. An inflatable thermal blanket was first disclosed in U.S. Pat. No. 4,572,188 assigned to Arizant Healthcare Inc., the assignee of the present application. U.S. Pat. No. 5,405,371, also assigned to Arizant Healthcare Inc., is directed to an inflatable thermal blanket that extends transversely across the arms and chest of a patient&#39;s body, and is for use during surgery at or below the patient&#39;s chest. These patents disclosed an airstream inlet: In later products, the airstream inlet port comprises a cardboard structure adhesively attached to the surface of the thermal blanket. A hole provided through the inlet port is sized to accept the end or nozzle of an inflation hose. In some thermal blankets, a plurality of inlet ports is provided to allow an inflation hose to be attached at any one of a plurality of locations on the blanket. When an operator inserts the inflation hose into an inlet port, the port is closed about the hose. The surface material of the thermal blanket which coincides with the inlet port is either removed or perforated in order to allow a warmed airstream to pass from the hose through the port to the interior of the thermal blanket. The warmed airstream enters the thermal blanket and is forced out a plurality of small exhaust holes in the lower surface of the thermal blanket. Typically, the user perforates or removes that portion of the thermal blanket which covers an inlet port only when that port is to be used. Accordingly, each of the unused inlet ports remains sealed until after the first use.  
         [0007]     One problem with this design is that if the operator decides in the middle of the procedure to move the inflation hose from one inlet port to another, the first port must be resealed or otherwise closed in order to prevent air from exiting through that port instead of through the holes on the lower surface of the blanket, as intended. A number of means have been used to reseal or close an inlet port after removal of an inflation hose. However, none of these means are completely satisfactory. For example, tape has been used to seal an open port, but is generally a nuisance to apply. The prior art suggests many other means and modes for sealing or closing an open port, including: adhesive strips, double sided tape, snaps, zippers, folding flaps, Ziplock®-type seal, hook and loop fastener strips, folding wire, or plastic bars. Each of these methods has a number of drawbacks. The method is either relatively costly, or it is inconvenient, requiring a great deal of attention or time of an operator, possibly during critical moments. Such methods and means require accommodation in manufacture of a thermal blanket, increasing production costs and decreasing manufacturability.  
         [0008]     Accordingly, it would be desirable to provide a method and apparatus for closing inlet ports in an inflatable thermal blanket such that the port may be opened and closed conveniently and repeatedly.  
       SUMMARY OF THE INVENTION  
       [0009]     An apparatus to warm a person includes an inflatable cover that can be disposed on a portion of the person&#39;s body. Two inlet ports are provided in the inflatable cover and a plug is removably received in at least one port of the two ports. The plug may have a planar central body and a plurality of extensions that are coplanar with the central body and which extend from the central body, at least two of which are receivable in the one port.  
         [0010]     Alternatively, the plug includes a flange, a substantially vertical ring-like wall receivable in the one port, and at least two protuberances which extend from the substantially vertical ring-like wall to resist removal of the plug from the one port.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is an illustration of the preferred embodiment of the present invention  
         [0012]      FIG. 2  is an illustration of the preferred embodiment of the present invention immediately before insertion into an inlet port.  
         [0013]      FIG. 3  is an illustration of the preferred embodiment of the present invention after insertion into an inlet port.  
         [0014]      FIG. 4  is an illustration of an alternative embodiment of the present invention.  
         [0015]      FIG. 5  is an illustration of the alternative embodiment of  FIG. 4  immediately before insertion into an inlet port.  
         [0016]      FIG. 6  is an illustration of the alternative embodiment of  FIG. 4  after insertion into an inlet port.  
         [0017]      FIG. 7   a  is an illustration of an embodiment of the invention having a distal end of an appendage tilted up ward.  
         [0018]      FIG. 7   b  is a side view of the embodiment of  FIG. 7   a.    
         [0019]      FIG. 8   a - 8   e  illustrates a number of alternative embodiments of the invention having varied appendages.  
         [0020]      FIG. 9   a  is an illustration of an embodiment of the invention having protuberances.  
         [0021]      FIG. 9   b  is a side view of an embodiment of the invention having retractable protuberances.  
         [0022]      FIG. 10  is a side view of the embodiment of  FIG. 9   a.    
         [0023]      FIG. 11  is an illustration of the embodiment of  FIG. 9   a  suspended over a port.  
         [0024]      FIG. 12  is an illustration of the embodiment of  FIG. 9   a  inserted in the port.  
         [0025]      FIG. 13  is an illustration of an embodiment having threads.  
         [0026]      FIG. 14  is an illustration of the embodiment of  FIG. 13  after insertion in the port.  
         [0027]      FIG. 15  illustrates the present invention in use with a conventional upper body inflatable thermal blanket.  
         [0028]      FIG. 16  shows the present invention in use with a lower body inflatable thermal blanket. 
     
    
       [0029]     Like reference numbers and designations in the various drawings refer to like elements.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]     Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than as limitations on the present invention.  
         [0000]     Overview  
         [0031]     The present invention is a plug for removably closing an inlet port of an inflatable thermal blanket. One preferred embodiment of the present invention is shown in  FIGS. 1-3 . As shown  FIG. 1 , the plug has a central body  102  that is essential circular and has a diameter equal to that of an inlet port with which the invention is to be used. Extending preferably radially outward from the central body  102  are a plurality of extensions  103 . In this embodiment of the present invention, an even number of opposing extensions are provided, as shown in  FIGS. 1-8 . These extensions  103  may be substantially curved, or rounded, like the leaves of a 4-leaf clover. Alternatively, the extensions may be generally pointed, as shown in  FIGS. 4-6 . Preferably four extensions  103  are provided. However, fewer than four extensions may be provided or, as shown in  FIG. 4 , more than four extensions  403  may be provided. The number of extensions is generally unrelated to the shape of each of the extensions. In accordance with the preferred invention, the plug is made of a generally flexible, resilient sheet of material, such as plastic or a wood pulp product, such as paper or cardboard. Preferably, the material is rigid enough to allow bending along a central axis through the center of the plug in predominantly one direction at a time. The material is preferably die-cut into the desired shape. Alternatively, the material may be stamped, extruded, molded or otherwise formed into the desired shape.  
         [0032]     In accordance with one method of the present invention, the plug is bent such that outer edges of opposing extensions may be inserted into an inlet port  201  (see  FIG. 2 ). The inlet port is typically a circular hole through a rectangular sheet  203  of cardboard. The sheet has a first (or, outer) surface  204 , and a second (or, inner) surface indicated by reference numeral  206 . Slits  205  about the perimeter of the port  201  allow the port to accommodate an end or nozzle of an inflation hose (not shown) which is slightly larger in outside diameter than the inner diameter of the port. As shown in  FIGS. 3 and 6 , when the plug  100  is released, the plug flattens across and substantially, if not entirely closes the port  201 . The plug is retained in the port by the extensions that engage the second (or, inner) surface of the sheet  203 . Preferably an equal number of extensions  103 ,  403  are placed inside the port  201  as remain outside the port although this is not vital to the practice of the invention.  
         [0033]     In an alternative embodiment of the present invention shown in  FIGS. 7   a  and  7   b,  the distal end of one or more of the extensions may be formed at an angle to allow the plug  700  to be more easily removed from the port  201 . Similarly, the distal end  705  of one or more extensions  703  may be formed at a slight angle downward to allow the present invention to be more easily inserted into a port  201 . It will be clear to those of ordinary skill in the art, that a number of alternative shapes may be used, as shown in  FIGS. 8   a - 8   e.    FIG. 8a  shows the present invention formed as a cross. Accordingly, each of the extensions  801  are essentially rectangular. As shown in  FIG. 8   b,  the present invention has extensions  803  which are notched at the distal end  805 . As shown in  FIG. 8   b,  the width of each extension  803  is less than the diameter of a central circular body  809  divided by the square root of 2. Accordingly, a portion  807  of the perimeter of the central circular body  809  forms a part of the perimeter of the plug  800 .  FIG. 8   c  illustrates an embodiment of the present invention in which four generally triangular shaped extensions  811  are provided.  FIG. 8d  illustrates an embodiment in which four relatively smaller generally triangular extensions  813  are provided.  FIG. 8   e  illustrates an embodiment of the present invention in which extensions  815  are generally rectangular having rounded distal ends  817 . It will be clear to those skilled in the art that numerous other shapes and configurations are possible. Those illustrated in  FIGS. 1 through 8  are merely provided as exemplars.  
         [0034]      FIG. 9   a  illustrates yet another embodiment of the present invention. The plug  900  in  FIG. 9   a  may be vacuum-formed from a sheet of plastic. The plug  900  preferably has a flange  901  which is larger in diameter than inlet port  201  with which the plug  900  is to be used. The flange prevents the plug  900  from passing completely though the port  201 . The invention has a generally vertical ring-like surface wall  903  that press fits into the inlet port  201 . Accordingly, the diameter of the surface wall  903  is essentially equal of to the diameter of the port  201  with which the plug  900  is to be used. The flange  901  preferably has a tab  905  which extends therefrom. The tab  905  provides the user with a handle to grasp when removing the plug  900  from a port  201 .  
         [0035]     Protruding from the wall  903  are a plurality of protuberances  907  which extend radially outward from the wall  903 . Each protuberance  907  has an upper and lower slope  909 ,  911 , respectively. The upper and lower slopes  909 ,  911  allow the plug  900  to be inserted and removed relatively easily, while resisting removal of the plug  900  from the port  201 , such that the plug  900  is retained under normal conditions but may be easily removed when desired.  
         [0036]     In accordance with one embodiment of the present invention, the flange  901  is sufficiently thick to allow the user to comfortably grasp the plug  900  when the plug  900  is filly inserted into an insertion port  201 . For example, in one embodiment, the flange  901  is approximately 0.25 inches thick.  
         [0037]     In one embodiment of the present invention shown in  FIG. 9   b  the protuberances  907  are retractable, and retract along the path indicated by arrow  913 . When force is applied against the protuberance  907 , an arm  915  flexes. A slit  917  frees the arm  915  from the wall  903  and allows the protuberance  907  to retract.  FIG. 11  shows the plug  900  suspended above the port  201  prior to insertion into the port.  FIG. 12  illustrates the plug  900  after insertion into the port  201 .  
         [0038]      FIG. 13  illustrates yet another alternative embodiment to the present invention. The plug  1300  is preferably molded from plastic. The plug  1300  is retained in the port  201  by spiral groves  13  molded/etched into the edges of the plug  1300  to form threads  1303 . The plug  1300  may be screwed into the port  201  and later unscrewed from the port  201 . The plug  1300  preferably has a flange  1301  which is larger than the port  201 . The body  1305  of the plug  1300  preferably has a diameter which is equal to or slightly larger than the diameter of the port  201 .  FIG. 14  is an illustration of the plug  1300  after insertion into a port  201 . Only the flange  1301  is visible in  FIG. 14 .  
         [0039]      FIG. 15  illustrates the inlet port plug  100  in use with a conventional upper body inflatable thermal blanket  1501 .  FIG. 16  shows the inlet port plug  100  in use with a lower body inflatable thermal blanket  1601 . The inlet port plug may generally be used with these and other inflatable thermal blankets.  
       SUMMARY  
       [0040]     A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the plugs shown in  FIGS. 1-6  may be fabricated from any generally resilient sheet of material.  
         [0041]     Furthermore, the nature of the material which defines the inlet port is not critical to the present invention. Accordingly, the sheet which forms the inlet port may be cardboard, plastic metal, ceramic, or any other material. Still further, the protuberances  907  shown in  FIGS. 9   a - 12  may form a single continuous ring about the ring-like vertical wall  903 . Still further yet, the angle of the lower and upper slope  909 ,  911  of the embodiment of the present invention shown in  FIGS. 9   a - 12 , may differ substantially from one another. Also, the plug  900  shown in  FIGS. 9   a - 12  may be formed without the tab  905 , and the flange may be formed at an angle other than 90° with the vertical wall  903 .  
         [0042]     Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiment, but only by the scope of the appended claims.