Abstract:
The present invention is a breathing mask that is fully adjustable so as to enable a comfortable and leak proof seal around a patient&#39;s face. The mask includes a frame, a cushion, a hose connector, a strap, connector, a strap, and a headgear. The present invention ensures both comfort and effectiveness by enabling a full adjustment of various components such as the angle of the strap relative to the face mask and the adjustment of the size of the headgear. Furthermore, the present invention also allows for the free rotation of certain elements in order to maintain a sufficient seal without increasing the pressure applied to the patient.

Description:
RELATED APPLICATIONS 
     This application claims benefit of U.S. Provisional Application No. 60/576,520, filed Jun. 3, 2004, and incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a breathing mask for use in the treatment of respiratory conditions and in assisted respiration. More particularly, the present invention relates to a nasal mask for use in the treatment of sleep breathing disorders. 
     BACKGROUND OF THE INVENTION 
     Breathing masks are commonly used for the delivery of gases to patients suffering from respiratory distress or from a respiratory ailment. These masks are connected to a gas source, and are used to form a relatively leak-proof seal around a patient&#39;s face. This seal enables the patient to breathe directly from the gas source or to maintain a particular airway pressure. Breathing masks are especially integral when the patient is being treated with a specific concentration of a particular gas or if the respiratory parameters of the patient are being monitored. Such applications include, the mechanical ventilation of patients and continuous positive airway pressure (CPAP) treatments for obstructive breathing disorders. 
     There are a variety of known breathing masks in the art. These masks typically include a frame which connects to a hose from a gas source, a cushion that connects to the frame and which creates a seal around a patient&#39;s face, and a strap for keeping the mask in place. While most known masks work for their intended purpose, many are unable to maintain a solid seal without having to apply a large amount of pressure on the patient&#39;s face. Because of the contours of the face, there is typically a tradeoff between the effectiveness of the seal and comfort during use. If a breathing mask applies too much pressure on the patient, the mask can cause discomfort or even create facial sores. For patients who require the use of a breathing mask during sleep, the discomfort of using the prior art masks may even prevent them from obtaining sleep. 
     In the treatment of obstructed sleep breathing, a nasal breathing mask is worn during sleep while CPAP treatments are applied. CPAP treatments provide a continuous positive pressure into the patients airway so that the airway is not allowed to collapse upon itself, enabling the patient to breathe easier during sleep. If the nasal breathing mask leaks, an insufficient amount of pressure is generated in the airway and the patient airway may collapse upon itself causing apnea, and other forms of sleep breathing disorders. Also, patient movement during sleep may cause the mask to displace forming additional leaks. The prior art masks remedy this situation by requiring a tighter fit between the patient and the mask. 
     However, it is also vital that the patient be able to sleep with the mask in place, so comfort is also imperative. By applying the mask too tightly, the patient is not able to sleep with the mask on or skin lesions may appear. Consequently, there is a need for a breathing mask which is able to accommodate the contours of the human face without requiring an excessive amount of pressure to ensure a seal around the patients face. 
     SUMMARY 
     The present invention is a breathing mask that maintains a relatively leak free seal around a patient&#39;s face without resorting to the application of excess pressure on the patient&#39;s face. The present invention accomplishes this by making the masks fully adjustable, and by enabling the hose to rotate around the mask so that the hose is generally prevented from knocking the mask out of position. The subject mask includes a frame, a cushion coupled to the frame, and a connector for connecting a headgear to the frame. A hose connects the mask to a gas source. 
     In one embodiment, the frame cooperates with the cushion to define an air proof chamber surrounding the patients face. An aperture extends through the frame in order to allow gas to pass therethrough. A lip circumferentially surrounds the aperture and forms a quick connect interface with the hose connector. The frame also includes interfacing surfaces located on opposite longitudinal ends of the frame. These interfacing surfaces form a quick connect interface with the strap connector 
     In one embodiment, a strap connector is used to couple the strap to the frame. The strap connector includes overlaying first plate and second plates. The first plate includes a tongue portion and a cantilevered clip portion which mate with the interfacing surfaces located on the frame. A pivot arm connects the first plate to the second plate, and enables the second plate to pivot relative to the first plate. The second plate includes locking arms which connect to the strap. The rotation of the second plate with respect to the first plate enables the patient to change the angle of the strap relative to the frame. Also, the length of the strap is adjusted by changing the position of the locking arms relative to the strap. 
     In one embodiment, the strap is coupled to a head gear. The headgear can be comprised of two separate C-shaped strips of material which interlock with the other along its longitudinal end. The size of the headgear is adjusted by reducing or lengthening the overlapping portions of the strips. In an alternative embodiment, the headgear includes a pair of base portions which are connected together by a headstrap. The headstrap is adjustable to accommodate varying head sizes, and may comprise two separate pieces with a fastener (such as a hook in loop fastener) connecting the two. A strap arm rotatably extends from each base portion. A neck strap extends between the two strap arms. The strap arm interlocks with the base portion in order to fix the position of the neck strap relative to the patient. 
     In one embodiment, a hose connector  14  includes a lip portion which is sized to be insertable within the aperture on the frame. A retaining ring couples the hose connector to the frame, while still allowing the hose connector and the hose to rotate freely about the frame. This reduces the ability of the hose to push the mask out of position 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       For the purpose of facilitating an understanding of the invention, there is illustrated the accompanying drawings, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated. 
         FIG. 1  an exploded view of one embodiment of the present invention. 
         FIG. 2   a  is a front view of one embodiment of a frame. 
         FIG. 2   b  is a sectional of the mask of  FIG. 2   a  taken along lines B-B. 
         FIG. 2   c  is a sectional view of the mask of  FIG. 2   a  taken along lines A-A. 
         FIG. 2   d  is an overhead view of the mask of  FIG. 2   a.    
         FIG. 2   e  is a side view of the mask of  FIG. 2   a.    
         FIGS. 3   a - g  are sectional views of different embodies of a cushion. 
         FIG. 4   a  is side view of one embodiment of the present invention. 
         FIG. 4   b  is an exploded view of one embodiment of a strap connector. 
         FIG. 4   c  is a side, exploded view of the strap connector of  4   b.    
         FIG. 5   a  is an exploded view of one embodiment of a neck strap arm. 
         FIG. 5   b  is an exploded view of a second embodiment of a neck strap arm. 
         FIG. 5   c - d  are sequential views of the operating configuration of one embodiment of a headgear. 
         FIG. 5   e  is a sequential view of the embodiment of the release mechanism of  FIG. 5   b  for a neck strap arm. 
         FIG. 6   a - b  are exploded views of one embodiment of the present invention. 
         FIG. 7  is a perspective view of one embodiment of the present invention. 
         FIG. 8  is a sectional view of the embodiment of  FIG. 7 . 
         FIG. 9  is a perspective view of an alternative embodiment of the present invention. 
         FIG. 10  is a perspective view of one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to a breathing mask for the delivery of gas from a gas source to a patient. For the purpose of explanation only, the present invention is described with respect to an embodiment which is adapted for nasal ventilation (nasal mask). One skilled in the art can readily ascertain that the present invention is easily adapted to accommodate a number of different breathing mask applications. 
     As shown in  FIG. 1 , in one embodiment, the present invention is a nasal breathing mask  8 , sized and configured to form a seal around a patient&#39;s nose. The mask  8  includes a frame  10 , a cushion  12 , a hose connector  14 , a strap connector  16 , a strap  18 , and a headgear  20 . A hose  22  connects the mask  8  to a gas source (not shown). The present invention maintains a relatively leak free seal around a patient&#39;s face without resorting to the application of excess pressure on the patient&#39;s face and the frame is designed to resist displacement by the hose  22 . This makes the mask  8  ideal for use in the application of CPAP to patients and for administering manual ventilation to unconscious patients. 
     As shown in  FIGS. 1 and 2   a - e , in one embodiment, the frame  10  in cooperation with the cushion defines a chamber  28  around the patient&#39;s nose. An aperture  23  enables gas to pass from the hose  22  through the frame and in to the patient&#39;s nose. A lip  24  circumferentially surrounds the aperture  23  and is sized and shaped to pneumatically interface with the hose connector  14 . The frame also includes interfacing surfaces  26  located on opposite longitudinal ends of the frame  10 . The interfacing surfaces  26  include structures which enable the frame to form a quick-release couple with the strap connector  16 . 
     As shown in  FIG. 1 , in one embodiment, the cushion  12  connects to the frame  14  and maintains a relatively air tight seal around a nose. The cushion  12  is sized and configured to allow some mask movement without breaking its seal with the face. The cushion is made from a resilient material such as a silicone elastomer. 
       FIGS. 3   a - f  disclose a number of different embodiments of cushion which can be used with the present invention.  FIGS. 3   a - b  discloses variations of a double wall design of cushion with a first membrane  30  overlaying a second membrane  32 . Both the first and second membranes are curved inwardly.  FIG. 3   c  discloses a triple wall design with a third inwardly curved membrane.  FIGS. 3   d - g  are variations of a single wall design having a single inwardly curving membrane  30 . All the cushions  12 , have resilient, inwardly curving flexible membranes which are compressed during use. The cushions  12  may also include air filled pockets or any other cushion designs which are known in the art. 
     As shown in  FIGS. 4   a - c , in one embodiment, a strap connector  16  couples the strap  18  to the frame  10 . The strap connector  16  includes a first plate  40  and a second plate  42 . The first plate  40  includes a tongue portion  44  and a cantilevered clip portion  46 . The tongue portion  44  and the clip portion  46  mate with the interfacing surface  26  located on the frame  10 . A pivot arm  48  extends from the first plate  40  and is received by the second plate  42 , coupling the two, and enabling the second plate  42  to pivot relative to the first plate. Opposing interlocking surfaces  50 ,  52  are located on the first  40  and second plate  42  respectively. The interlocking surfaces fix the position of the second plate  42  relative to the first plate  40 , thereby setting the angle of the strap  18  relative to the frame  10 . 
     In one embodiment, the second plate  42  includes locking arms  54  which couple to the strap  18 . The locking arms  54  engage apertures  41  which are positioned longitudinally along the strap  18 . The rotation of the second plate  42  with respect to the first plate  40  determines the angle of the strap relative to the frame  10 . Consequently, the present invention enables the strap to be adjusted lengthwise and angularly in order to establish a secure but comfortable fit with the frame  10 . 
     As shown in  FIG. 1 , in one embodiment, the strap  18  is coupled to a headgear  20  via a connector  95  which is coupled to the headgear by a pivot  98 . This enables the headgear  20  to rotate relative to strap  18 , allowing the patient to optimize the positioning of the headgear  20 . The headgear  20  is comprised of two separate C-shaped strips  97  of material which interlock with each other. The size of the headgear  20  is adjusted by reducing or lengthening the overlapping portions of the strips  97 . 
     In an alternative embodiment, shown in  FIGS. 5   c - d , the strap  18  is integrated into the headgear  60 . The headgear  60  includes a pair of base portions  61  which are connected together by a headstrap  62 . The headstrap  62  is adjustable to accommodate varying head sizes, and may comprise two separate pieces with a fastener (such as a hook in loop fastener) connecting the two. The strap  18  extends from the base portion  61 . A strap arm  63  extends from each base portion  61 . A neck strap  64  extends between the two strap arms  63 . Each strap arm  63  interlocks with the base portion  61  in order to fix the position of the neck strap  64  relative to the patients head. As shown in  FIGS. 5   c - d , the strap arms are first positioned to be adjacent the headstrap  62 . The headgear  60  is then placed on a patient&#39;s head and the strap arms  63  rotate downward to optimally position the neck strap  64  relative to the patient&#39;s neck. 
     The locking mechanism for the strap arms  63  may include known ratcheting structures. One such example, as shown in  5   a , involves the use of knock out spacers  66  located on the strap arms  63  and interlocking flanges  68  located on the base portion  61 . In this embodiment, the flanges  68  interlock with the knock out spacers  66  to fix the angle of the strap arm  63 . A release button  70 , pushes the interlocking flanges  68  downward and disengages them from the knock out spacers  66 . 
     In an alternative embodiment as shown in  FIGS. 5   b  and  5   e , the rotating strap arm  63  interlocks to the base portion  61  through a triple plate mechanism. A base plate  72  is secured to the base portion  61 , and the base portion  61  is coupled to the middle plate  74 . A raised surface  76  on the middle plate engages the strap arm  63  and locks the -strap arm  63  in place. A release button  78  disengages the raised surface  76  from the strap arm  63 , and allows the strap arm  63  to rotate freely about the base portion  61 . This enables the neck strap to be positioned optimally with respect to a patient&#39;s neck. 
     As shown in  FIGS. 6   a - b , in one embodiment, hose connector  14  connects to the frame  10  on a side opposite the cushion  12 . The connector  14  includes a lip portion  80  which is sized to be insertable within the lip  24  and aperture  22  of the frame  10 . A retaining flange  82  encircles the lip portion  80 . A complementary retaining flange  84  is located on the lip of the frame  10  and it engages its counterpart on the hose connector  14  to locate the lip portion  80  within the aperture  22 . A retaining ring  86  couples the hose connector  14  to the frame  10 , while still allowing the hose connector  14  to rotate freely about the frame. Other known means for maintaining a rotatable connection between the hose  22  and the frame  10  may be incorporated into the present invention. The ability of the hose to rotate deflects pressure applied by the hose to the frame. This significantly reduces the ability of the hose  22  to push the mask of off the patient&#39;s face or to cause the mask to break its seal. 
     As shown in  FIGS. 7-9 , in an alternative embodiment of the present invention, retractable pads  90  and  92  are used to support the cushion in the area that would contact the bridge of the nose. The pads  90  and  92  are located beneath the cushion and may be saddle shaped to accommodate the bridge of the nose. Additional pads  96  may also be included to support other areas of the cushion. 
     The pads  90 ,  92 ,  96  extend from or retract into the frame  10 . The pad  90 ,  92 ,  96  are coupled to a stem  98 , and the stem  98  is in geared communication with a wheel  100 . Rotation of the wheel  100 , translates the stem  98  causing it to extend from or retract into the frame  10 . The pad  90 ,  92 ,  96  move in unison with the stem  98 . 
     In another alternative embodiment shown in  FIG. 10 , the present invention is supplemented with physiological sensors to enable the monitoring of a patients physiological parameters during sleep. A monitoring band  110  is connected between the two base portions  61 . The monitoring band  110  is positionable so that the sensors attached thereto are able to be optimally positioned. These sensors can include electroencephalogram (EEG), electromyogram (EMG), oximetry, and electrocardiogram (ECG). Furthermore, physiological sensors can be implemented in the strap  18 . A thermistor  112  can also be connected to the frame  10  to detect air leaks and mouth breathing. 
     While the subject invention has been described with reference to several embodiments thereof, those skilled in the art will recognize various changes that may be made without departing from the spirit and scope of the claimed invention. Accordingly, this invention is not limited to what is shown in the drawings and described in the specification. Any numbering or ordering of elements in the following claims is merely for convenience and is not intended to suggest that the ordering of the elements of the claims has any particular significance.