Patent Publication Number: US-2018049915-A1

Title: Forced air temperature regulating pad with chest warming feature

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 14/574,722 filed on Dec. 18, 2014, which application claims priority to U.S. Provisional Application No. 61/918,668 filed on Dec. 20, 2013. This application also claims priority to U.S. Provisional Application No. 62/409,794 filed Oct. 18, 2016. 
    
    
     BACKGROUND 
     Hypothermia is a recognized common occurrence for patients during surgery. Patients who develop hypothermia are at a greater risk for complications, including a greater chance of heart problems, high rates of infection, increase blood loss and prolonged recovery. To counter this, medical personnel may cover the patient with blankets. Blankets are typically bulky, frequently unravel, and may fall off the patient during pre-surgery, surgery, post-surgery, or transport. Additionally, blankets may pose a safety risk and may interfere with the doctor or other personnel&#39;s ability to care for the patient. The use of forced warm air blankets or pads is known in the art; however, there are several downfalls. For example, these types of devices typically infuse predetermined high-temperature air through a bladder or pad to maintain the patient&#39;s body temperature in the normal range. The technology often utilizes a double layer or bladder type blanket made of a thin air proof bottom material in a perforated top layer. Warm air is forced into the bladder such that warm air is allowed to escape the perforated top layer and come in contact with the patient&#39;s skin area that is exposed to the blanket or pad. The shortcomings of this technology is that the tiny air jets coming out from the double layer blanket or pad can generate are relatively turbulent and, therefore, can cause the excitement of dust contained in or adjacent to the blanket or pad. This turbulent and potentially dusty air can compromise the otherwise engineered and sterile airflow created in the operating room. There are concerns, though not proven, of increased infection associated with the use of forced warm air technology using the traditional double layer or bladder technology as a result of the dust problem. 
     In addition, traditional under-body temperature regulating pads do not have the ability to directly warm (or cool) the portion of the patient&#39;s body that is not in contact with the underlying pad. For example, if the patient is laying supine on his or her back, the anterior of the body is not in direct contact with the underlying pad and, therefore, the chest, torso, legs and the like can only be warmed (or cooled) from the pad through indirect airflow. 
     Accordingly, the present disclosure is directed to a temperature regulating pad or blanket that has reduced turbulence of air coming exiting the blanket or pad to the patient. The temperature regulating pad or blanket is configured to generate an even air distribution (whether warm or cool) through the blanket toward the patient. Additionally, the temperature regulating pad or blanket includes a slot such that the pad can be folded over on top of the patient&#39;s upper body or lower body regions to provide additional warming capability directly to the exposed surface of the body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of the temperature regulating pad. 
         FIG. 2  is a cross-sectional view of one embodiment of the temperature regulating pad. 
         FIG. 3  is a top view of the middle layer of the temperature regulating pad, showing the construction thereof 
         FIG. 4  is a perspective view of one embodiment of the temperature regulating pad in an inflated state with forced warm air passing therethrough. 
         FIG. 5  is a cross-sectional view of one embodiment of the temperature regulating pad in an inflated state with forced warm air passing therethrough. 
         FIG. 6  is a perspective view of another embodiment of the temperature regulating pad with the chest flap feature. 
         FIG. 7A  is a perspective view demonstrating a patient disposed on the temperature regulating pad shown in  FIG. 6  with the chest flap feature un-deployed. 
         FIG. 7B  is a perspective view demonstrating a patient disposed on the temperature regulating pad shown in  FIG. 6  with the chest flap feature deployed. 
         FIG. 8A  is a view of one embodiment of the temperature regulating pad in an inflated state in use with a patient on surgical table, demonstrating the flow of warm air. 
         FIG. 8B  is another view of one embodiment of the temperature regulating pad in an inflated state in use with a patient on surgical table, demonstrating the flow of warm air. 
         FIG. 8C  is yet another view of one embodiment of the temperature regulating pad in an inflated state in use with a patient on surgical table, demonstrating the flow of warm air. 
         FIG. 9  is a perspective view of one embodiment of the temperature regulating pad in an inflated state in use with a patient on surgical table and attached to a warm air source. 
     
    
    
     DETAILED DESCRIPTION 
     Shown in  FIG. 1  is temperature regulating pad  1  generally configured as a planar element having a top layer  10 , a middle layer  11 , and a bottom layer  12 . Temperature regulating pad  1  is shown at least partially transparent in  FIG. 1  whereby a plurality of seal lines  14  attaching middle layer  11  to bottom layer  12  can be seen. Air inlet  13  may also be provided, in some embodiments, along the bottom edge  15  of the temperature regulating pad  1 . Other locations for the air inlet  13  are suitable, for example on a side edge or the top edge of the pad  1  or other such location that will permit unobstructed flow of forced air. The temperature regulating pad  1  may be configured as a standalone device to be placed on a stretcher, surgical table, bed, or other support surface. Alternatively, the temperature regulating pad  1  may be configured to be inserted into a sheet or pocket provided, for example, in the patient positioning device described in Applicant&#39;s patient positioning device invention described in U.S. application Ser. No. 14/340,611, U.S. application Ser. No. 13/359,734 and U.S. Pat. No. 8,661,580. 
       FIG. 2  shows a cross-section of the temperature regulating pad  1 . As shown, middle layer  11  is disposed between bottom layer  12  and top layer  10 . This construction divides the temperature regulating pad  1  into an upper airspace  21  delimited by the top layer  10  and middle layer  11 , and a lower airspace  22  delimited by the middle layer  11  in the bottom layer  12 . An external airspace  23  is located about and above top layer  10  and generally defines the area in which forced air is communicated to a patient resting on the temperature regulating pad  1 . In some embodiments, a plurality of seal lines  14  attach the middle layer  11  to the bottom layer  12  at spaced apart intervals across the width of the temperature regulating pad  1 . Referring back to  FIG. 1 , seal lines  14  are also disposed along the length of the pad  1  in spaced-apart fashion. In some embodiments, seal lines  14  are disposed in a matrix formation with respect to the surface of the temperature regulating pad  1 . Air inlet  13  shown in  FIG. 1  is located to be in flow communication with and introduce air into the lower airspace  22  and, therefore, is disposed between the middle layer  11  and bottom layer  12 , in some cases along the bottom edge  15  thereof although other positions around the exterior perimeter of the temperature regulating pad  1  may be equally suitable. 
     In some embodiments, bottom layer  12  comprises a low friction nylon material and is substantially impermeable to air and is waterproof In some embodiments, the middle layer  11  comprises a thin plastic sheet of which at least a portion of is perforated to include a plurality of apertures  111 . In some embodiments the apertures  111  are dispersed evenly along at least a portion of the surface area of the middle layer  11 . In some embodiments, the top layer  10  comprises an air-permeable, breathable but waterproof material, such as polypropylene, which will allow air to pass through from the upper airspace  21  to the external airspace  23  in order to warn a patient disposed on the temperature regulating pad  1 . 
       FIG. 3  is a top view of an embodiment of the middle layer  11  showing the construction thereof In some embodiments, middle layer  11  includes a perforated center section  30  comprising the aforementioned perforated surface of the middle layer  11 , which is surrounded by an impermeable border  31 . As shown, the perforated center section  30  includes the plurality of apertures  111  disposed therethrough. The impermeable border  31  reinforces the construction of the temperature regulating pad  1  and also assures that air is forced up through the perforated center section  30  and does not get trapped at the terminal sides of the temperature regulating pad  1 . The width of the impermeable border  31  can vary depending on the desired construction; however, it should be sufficiently wide such as to generally cause the majority of introduced air to pass through the perforated center section  30 , rather than to get trapped at the edges of the temperature regulating pad  1 . 
     In some embodiments, the impermeable border  31  has a substantial transverse thickness relative to the overall width and length of the pad  1  such that the border  31  comprises a substantial portion of the surface area of the middle layer  11 . In some embodiments, the thickness is substantially wider than an ordinary seal line. In some embodiments, the width of the perforated center section is approximately half of the entire width of the pad, with the impermeable border comprising the remaining width, at least with respect to the middle layer  11 . 
     In other embodiments, the width of the perforated center section is approximately two-thirds of the width of the pad, with the impermeable border comprising the remaining width, at least with respect to the middle layer  11 . As noted, the relatively wide impermeable border  31  assures that air is forced through the center section  30  to the body mass of the patient and prevents air from being trapped, wasted, or lost at the terminal sides of the pad  1  where such air would otherwise provide no appreciable airflow at or toward the patient resting thereon.  FIGS. 4 and 5  depict the temperature regulating pad  1  in an inflated or action state. 
       FIGS. 6, 7A, and 7B  demonstrate another embodiment of the temperature regulating pad  1  having a chest warming feature. The pad  1  includes a slot  80  provided through the three layers of the pad  1 , namely the air-permeable top layer  10 , a perforated middle layer  11 , and the bottom layer  12 . In some embodiments, the slot  80  is generally U-shaped or C-shaped although other shapes can be implemented provided the structure and functionality of the resultant construction remains intact. In some embodiments, the slot  80  is integrated into the construction of the pad and the internal edges of the pad delimiting the side walls of the slot  80  are sealed and otherwise constructed in accordance with and without departing from the general structure of the pad  1  as described elsewhere herein. 
     With reference to  FIGS. 7A and 7B , with the slot  80  positioned substantially toward one end of the pad  1 , the slot  80  delimits a portion of the pad  1  shown as upper flap  81 . This flap is initially located at or about the head and shoulder area of a target patient resting on the pad  1 . The flap  81  will comprise substantially the same geometry as the slot  80 . For example, in  FIG. 7A  the slot  80  is a substantially squared off U-shape. As will be apparent, the shape and size of the slot  80  is designed to conform to the relative anatomy of the patient so that the flap  81  can move over and around the patient while also leaving sufficient surface area of the pad  1  to accommodate the patient&#39;s body. In some embodiments, the width of the slot is at least half of the entire width of the pad  1  and, in some embodiments, is greater than half of the entire width of the pad  1 . In some embodiments, the width of the slot  80  is at least as wide as the perforated center section  30  of the middle layer  11  shown in  FIG. 3 . It is appreciated that the location of the slot  80  can be varied in order to provide a flap  81  of various sizes and locations. As such, the depicted example shows the flap  81  positioned at the top of the pad  1  to provide an upper body warming feature. However, the flap  81  could be as well position toward the bottom of the pad to provide a lower body warming feature. Accordingly, reference herein to the flap  81  being a “chest warming feature” is merely illustrative as it indicates the most likely practical application but it certainly is not the only practical application. 
     The slot  80  releases the structure of the pad  1  to provide a means by which the flap  81  is foldable so that the flap can be folded over a portion of the pad  1  and such that the top layer  10  of the pad  1  is brought in contact with the exposed portion of the patient for supplemental temperature control. In the case where the patient is laying on his or her back, the anterior portion of the body is exposed and without the flap  81  could only otherwise be warmed (or cooled) by indirectly airflow from the pad  1 . More specifically, as shown in  FIGS. 7A and 7B , in some embodiments the flap  81  is configured move from a first, un-deployed position wherein the flap  81  is substantially aligned to the rest of the top surface of the pad  1  to a second, deployed position wherein the flap  81  is rotated upward and folded over toward the center of the pad  1  such that the flap  81  (and the portion of the top layer  10  thereof) rests on the torso area of a target patient resting on the pad  1 . The arrows in  FIG. 7B  indicate the general direction of the folding action. To facilitate the folding action, in some embodiments the pad  1  includes transverse fold lines  82  comprising seal lines extending from each of terminal ends of the slot  80  to the respective outer edges of the pad  1 . The fold lines  82  delimit a point of inflection or apex where the folding will occur and will allow the flap  81  to fold over with ease and precision. In some embodiments, the fold lines  82  comprise seal lines that draw together and attach the three layers of the pad  1 , like the other seal lines described herein. 
     In some embodiments the flap  81  is configured to rest on anterior chest and torso area of the patient in order to provide temperature control, i.e. warming or cooling, capability directly to the critical core area of the patient that would not otherwise receive direct airflow from the underlying pad  1 . As noted above, the location of the slot  80  and thus the flap  81  can be varied depending on where directly warming (or cooling) is desired. Likewise, the pad  1  depicted in the figures could simply be inverted if one desires to warm the lower body. Heated (or cooled) air circulates through the pad  1 , including through the flap  81  and exits through the flap  81  through the portion of the top layer  10  thereof, which top layer  10  is in contact with the patient. Accordingly, the flap  81  supplements the warming (or cooling) that is already provided by the under-body portion of the pad  1  by bringing the forced air directly over the chest and torso area of the patient. 
       FIGS. 8A-8C  show various stages of the inflated state of the temperature regulating pad  1  from an end view in use with a patient  40  resting on an underlying support surface  50 . Here it can be seen more closely how flap  81  is configured to rotate upward such that it folds over, in this example, clear of the head of the patient and resting on the chest and upper torso area of the patient. 
       FIG. 9  shows a perspective view of the temperature regulating pad  1  in use in conjunction with a forced air source  60 . Air from an external source  60  is provided into lower airspace  22  through air inlet  13  at the bottom edge of the temperature regulating pad  1 . In some embodiments, air inlet  13  is configured to receive a hose or tubing from a forced air machine such as a compressor or the like that provides an air source  60 . As air is forced through air inlet  13 , the temperature regulating pad  1  at least partially inflates forming channels  121  disposed lengthwise in lower airspace  22  which are delimited by the plurality of seal lines  14  attaching the middle layer  11  to the bottom layer  12  ( FIG. 8A ). In some embodiments this causes middle layer  11  to expand upward with respect to bottom layer  12  such that the channels  121  form a substantially cylindrical or semi-cylindrical profile as shown in  FIG. 5 . As these channels are formed, a pressure differential is created and air proceeds from lower airspace  22  through apertures  111  of middle layer  11  and into upper airspace  21  ( FIG. 8B ). The air continues through the air-permeable breathable surface of the top layer  10  and into the external airspace  23  surrounding the patient  40  ( FIG. 8C ). 
     Accordingly, with a patient  40  disposed on top of top layer  10  as air is forced through the temperature regulating pad  1 , air exits through the top layer to surround the patient to increase and/or maintain the patient&#39;s body temperature. Also shown is the flap  81  deployed and rest on the chest of the patient providing supplemental temperature control for the upper torso area that would not otherwise be in direct contact with the underlying pad  1 . As shown in  FIG. 4 , air will flow through the channels  121  up and through the top layer  10  in an upward and outward direction toward the patient. 
     Also as shown in  FIGS. 8A-8C , an optional oversheet  70  may be provided which at least partially surrounds the patient  40  and the external airspace  23 . In some embodiments, the oversheet  70  may comprise a thin plastic or polypropylene material and may include adhesive portions and/or an adhesive border to secure the oversheet  70  to the sides or bottom of the underlying support surface  50 . 
     With the air initially forced into lower airspace  22 , the air pressure inside lower airspace  22  is greater than the pressure inside upper airspace  21 . The air pressure inside upper airspace  21  is greater than that of external airspace  23 . Thus, a pressure gradient or differential is created with higher pressure lower airspace  22  as compared to that of the external airspace  23 . As the air enters inlet  13  and into lower airspace  22 , channels  121  and then the air flows through the apertures  111  of the middle layer  11  and into upper airspace  21 . Due to the pressure differential, the air then moves through the permeable top layer  10  into the external airspace  23 . The air exiting the top layer  10  is at a much lower pressure and velocity in the air exiting from the lower airspace  22  to the upper airspace  21  through middle layer  11 . Accordingly, the turbulence of the air exiting through top layer  10  is less than the turbulence of the air exiting through middle layer  11 . Thus, the air exiting top layer  10  toward the patient is much less turbulent than the air exiting the middle layer  11 . The temperature regulating pad  1 , therefore, is effective in reducing the air turbulence around the patient thereby minimizing the production and movement of dust in the operating room while still adequately maintaining or increasing the body temperature of the patient. In that sense, any residual dust inside the pad  1  from manufacturing or storage is less likely to be pushed through and out of the pad  1  and into the surgical environment. In some embodiments, therefore, the top layer  10  is air-permeable to function as an air filter to permit the flow of air out but prevent or significantly limit the flow of dust and other particulates. 
       FIG. 9  shows an embodiment of the temperature regulating pad  1  showing the various airspaces with an exemplary patient  40  disposed thereon and subjected to the air flow that the pad  1  herein provides, including the flap  81  which provides temperature regulation to the chest area. 
     The temperature of air provided through the pad  1  can vary as needed although in many instances relatively warm air will be desired in order to maintain the patient&#39;s body temperature during a procedure such as surgery. In some embodiments, the forced air is relatively warm, between 22 and 43 degrees Celsius, in order to regulate the patient&#39;s body temperature toward the desired 36-37 degrees Celsius range and to otherwise prevent or alleviate hypothermia. In other embodiments, the forced air may be relatively cool, between 18 and 22 degrees Celsius, in order to reduce the patient&#39;s body temperature in the case of hyperthermia, pyrexia (fever), or other scenarios where it is desirous to reduce the patient&#39;s body temperature. 
     As noted above, certain materials may be selected for each of the top layer  10 , middle layer  11 , and bottom layer  12  to promote the functionality of the pad  1 . For example, the top layer  10  may comprise a comfortable material such as polypropylene that is air permeable and breathable to permit air to pass through but prevents or limits the passage of dust or other particulates. In some embodiments, the top layer  10  is permeable to air but prevents or substantially reduces the passage of dust or other particulate, in effect acting as an air filter. The middle layer in some embodiments comprises a thin plastic that includes the aforementioned apertures  111  and also permits for seal lines to be created between it and the bottom layer  12 , which seal lines  14  may be constructed by heat sealing or other known construction methodology. In some embodiments bottom layer  12  comprises an impermeable low friction material such as nylon to facilitate movement of a patient with respect to an underlying support surface. It is appreciated and understood that the temperature regulating pad  1  is generally suitable for regulating the temperature of a patient and need not necessarily be used with warm air. In certain applications, the pad  1  could be equally used with forced cool air and would function substantially as explained and described herein. 
     The temperature regulating pad  1 , in some embodiments comprises an air-permeable polypropylene top layer  10 , a perforated plastic middle layer  11 , and an impermeable low friction nylon bottom layer  12 . The perforated middle layer  11  is disposed between the top layer  10  and the bottom layer  12  and is at least partially attached to the bottom layer by a plurality of spaced apart seal lines  14 . The top layer  10  and the perforated middle layer  11  delimit an upper airspace  21 . The perforated middle layer  11  and the bottom layer  12  delimit a lower airspace  22 . Forced air of a desired temperature is received into the lower airspace  22  and flows from the lower airspace  22  into the upper airspace  21  through the perforated middle layer  11 . The forced air exits the air-permeable top layer  10  into an external airspace  23  about said top layer  10  to regulate the temperature of a patient  40  resting on the pad. The air exiting the air-permeable top layer  10  into the external airspace  23  is less turbulent than the air flowing from the lower airspace  22  to the upper airspace  21  to limit the excitement of dust and particulate in and around the area surrounding the pad. 
     While specific embodiments have been described in detail in the foregoing detailed description and illustrated in the accompanying drawings, those with ordinary skill in the art will appreciate that various modifications and alternatives to those details could be developed in light of the overall teaching of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims in any and all equivalents thereof