Abstract:
A forehead support for a respiratory mask is disclosed. A forehead pad is connected to the shell of a respiratory mask by two support legs providing increased stability over forehead supports of the prior art. A threaded piece connects one support leg to the shell of the respiratory mask such that turning the threaded piece causes the support leg continuously to move toward or away from the respiratory mask.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application claims the benefit of provisional application Ser. No. 60/717,126 filed Sep. 14, 2005, which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention relates to a system for supporting a respiratory mask used to supply a breathable gas to a wearer. More specifically, it relates to a forehead support for both nasal and full-face respiratory masks (hereinafter, collectively, “masks”or, separately, a “mask”).  
       BACKGROUND INFORMATION  
       [0003]     A number of relatively common breathing disorders are treated by delivering pressurized, breathable gas to a patient&#39;s airways. This is customarily done through the use of a mask.  
         [0004]     A mask is normally held in place over a patient&#39;s nose or face by one or more straps. The straps encircle the patient&#39;s head and are adjusted to create a gas tight seal between the mask and the patient&#39;s face.  
         [0005]     In use, the mask may push too strongly on the soft tissue surrounding the patient&#39;s nose or face. Also, the mask may, during extended use, move relative to the patient&#39;s nose or face breaking the gas tight seal or becoming uncomfortable.  
         [0006]     The prior art includes examples of a forehead support for a mask to prevent the mask from pushing too strongly on a patient&#39;s nose or face and to provide a point of contact between the mask and the patient&#39;s head, thereby reducing unwanted movement of the mask.  
         [0007]     For example, U.S. Pat. No. 6,679,261 discloses an adjustable forehead support for a facial mask that utilizes a dual-arm system wherein the angle between the arms can be altered between predetermined positions to alter the angle of the mask relative to the patient&#39;s head.  
         [0008]     Another example is disclosed in U.S. Pat. No. 6,532,961, in which a T-shaped forehead support is pivotally mounted to a facial mask so that it moves about an axis substantially parallel to the upper cross portion of the T-shaped support. The forehead support is selectively lockable at one of a number of predetermined angular positions.  
         [0009]     It is an object of the present invention to provide an alternative form of forehead support for a mask that provides increased stability for the mask relative to a patient&#39;s face.  
         [0010]     It is a further object of the present invention to provide a form of forehead support wherein the position of the forehead support is continuously adjustable.  
         [0011]     It is yet a further object of the present invention to provide a form of forehead support wherein the piece of the forehead support that contacts a patient&#39;s head more readily adjusts to the relative location of the patient&#39;s forehead.  
       SUMMARY OF THE INVENTION  
       [0012]     The present invention is a forehead support for a respiratory mask. In a preferred embodiment, a forehead pad is pivotally connected to one end of a cross-piece, providing a more readily adjustable contact with a patient&#39;s forehead than forehead supports of the prior art. The cross piece is, in tern, pivotally connected to the ends of two support legs of uneven length. The other ends of the support legs are pivotally connected to the shell of the respiratory mask. The two support legs provide increased stability for the forehead support compared to forehead supports of the prior art.  
         [0013]     The preferred embodiment also includes a means for adjusting the position of the forehead support relative to the respiratory mask. These means take the form of a threaded piece, one end of which is inserted in a thread hole in one of the support legs such that turning the threaded piece causes the support leg to move toward or away from the respiratory mask. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein:  
         [0015]      FIG. 1  is a front view (side away from a patient&#39;s face) of a preferred embodiment of the present invention;  
         [0016]      FIG. 2  is a rear view (side toward a patient&#39;s face) of the preferred embodiment of the present invention shown in  FIG. 1 ;  
         [0017]      FIG. 3  is a side view of the preferred embodiment of the present invention shown in  FIG. 1 ;  
         [0018]      FIG. 4  is a more detailed side view of the preferred embodiment of the present invention shown in  FIG. 3 ; and  
         [0019]      FIG. 5  is a side view of an alternative preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]      FIG. 1  shows a preferred embodiment of a forehead support for a respiratory mask according to the present invention. A respiratory mask  10  is connected to a forehead support  20 . The mask  10  includes a mask shell  11  and a mask cushion  12  for contacting a patient&#39;s face. The mask shell  11  includes a connector  13  for connecting to a supply of breathable gas. The mask  10  also includes slotted connectors  14  that can be used to connect ends of a lower head strap (not shown) to the mask  10 . The connectors  14  are shown here as slotted to accept the ends of the strap. The connectors  14  may employ other means of connection, including Velcro and magnets, known to those skilled in the art.  
         [0021]      FIGS. 2 and 3  show the forehead support  20  of the present invention in more detail. It comprises a forehead pad  21  with a substantially flat face  22  that contacts a wearer&#39;s forehead. The shape of the face  22  is a “lima bean” shape in this embodiment. The forehead pad  21  is pivotally connected to the first end  23  of a cross piece  24 . The second end  25  of the cross piece  24  is pivotally connected to the first end  26  of a first support leg  27 . The first end  28  of a second support leg  29 , which is shorter than the first support leg  27 , is connected to a mid-point  30  of the cross-piece  24 , which mid-point  30  is between the first end  23  and the second end  25 , but need not be midway between them. The second end  31  of the first support leg  27  is pivotally connected to the mask shell  11 , and the second end  32  of the second support leg  29  is pivotally connected to the mask shell  11 . The cross piece  24  and the support legs  27 ,  29  in this embodiment are all substantially in one plane. The axes of the pivotal connections described above are all substantially orthogonal to this plane. The two support legs  27 ,  29  are employed to increase the stability of the forehead pad  21  relative to the mask  11 .  
         [0022]     The first support leg  27  includes connectors  33  that can be used to connect ends of an upper head strap (not shown) to the first support leg  27 . The connectors  33  are shown here as slotted to accept the ends of the strap. The connectors  33  may employ other means of connection, including Velcro and magnets, known to those skilled in the art. Alternatively, in another embodiment, the second support leg  29  may include the connectors.  
         [0023]     The system for supporting a mask of the present invention also includes a means for continuously adjusting the position of the forehead support  20 . As shown in  FIG. 4  for the first embodiment, the first end  40  of a threaded piece  41  is attached to the mask shell  11  so that the threaded piece  41  can be turned freely by the knob  42 , or other means to turn the threaded piece  41 , attached to a mid point  44  of the threaded piece  41 , which mid-point  44  is between the first end  40  and the second end  44 , but need not be midway between them. The second end  44  of threaded piece  41  is inserted into a threaded hole  45  in the first support leg  27  so that turning the threaded piece  41  causes it continuously to move the first support leg  27  toward or away from the mask  10 , thereby moving the first end  23  of the cross piece  24  toward or away from the mask shell  11  and the forehead  50  of a wearer. Alternatively, in another embodiment, (not shown), the second end of the threshold piece is inserted into a threaded hole in the second support leg.  
         [0024]     The movement of the first end  26  of the first support leg  27  causes the cross piece  24  to rotate around both the point at which first support leg  26  is pivotally attached to it and the point at which the second support leg  29  is pivotally attached to it. This in turn causes the first end  23  of the cross piece  24  to trace an elliptical path. In another embodiment (not shown), if the forehead pad is connected to the first end of the cross-piece so that the forehead pad does not pivot, it will “roll” over the patient&#39;s forehead as it travels the elliptical path. In the preferred embodiment of  FIG. 4 , because the forehead pad  21  is pivotally connected to the first end  23  of the cross-piece  24 , the face  22  of the forehead pad always maintains the same flat contact with the wearer&#39;s forehead  50  increasing the stability of the mask  10  relative to the wearer&#39;s face.  
         [0025]     Referring again to  FIGS. 3 and 4 , the forehead pad  21  may be formed from a number of materials including foam or silicone and may be one pad or multiple pads joined together. The forehead pad  21  may also include a frame to hold said pad or pads. The cross piece  24 , first support leg  27 , and second support leg  29  are preferably made of plastics, but other similar materials known to those skilled in the art may be used. The threshold piece  41  and knob  42  it are preferably made of brass or stainless steel, but other similar materials known to those skilled in the art may be used.  
         [0026]      FIG. 5  shows a second embodiment of the forehead support of the present invention that is substantially similar to the first embodiment described above except that in this embodiment, the first support leg  61  and the second support leg  62  are equal length. Turning the threaded piece  41  again causes first end  63  of the first support leg  61  to move toward or away from the mask shell  11 , thereby moving the forehead pad  21  toward or away from the wearer&#39;s forehead  50 . However, when the support legs  61  and  62  are equal length, the cross piece  24  does not rotate. It moves both horizontally and vertically without rotation. This motion may further increase the stability of the mask  10  relative to the wearer&#39;s face.  
         [0027]     While the principles of the invention have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention.