Patent Publication Number: US-2013228173-A1

Title: Patient interface device with quick release mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application claims the priority benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/416,317 filed on Nov. 23, 2010, the contents of which are herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to respiratory therapy systems, such as non-invasive ventilation and pressure support systems, and, in particular, to a patient interface device for a respiratory therapy system that includes a quick release mechanism that allows the headgear component of the patient interface device to be quickly and easily loosened and tightened. 
     2. Description of the Related Art 
     There are numerous situations where it is necessary or desirable to deliver a flow of breathing gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in their esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver positive airway pressure (PAP) therapy to treat certain medical disorders, the most notable of which is obstructive sleep apnea (OSA). Known PAP therapies include continuous positive airway pressure (CPAP), wherein a constant positive pressure is provided to the airway of the patient in order to splint open the patient&#39;s airway, and variable airway pressure, wherein the pressure provided to the airway of the patient is varied with the patient&#39;s respiratory cycle. Such therapies are typically provided to the patient at night while the patient is sleeping. 
     Non-invasive ventilation and pressure support therapies as just described involve the placement of a patient interface device, including a mask component having a soft, flexible cushion, on the face of a patient. The mask component may be, without limitation, a nasal mask that covers the patient&#39;s nose, a nasal cannula having nasal prongs that are received within the patient&#39;s nares, a nasal/oral mask that covers the nose and mouth, or a full face mask that covers the patient&#39;s face. Such patient interface devices may also employ other patient contacting components, such as forehead supports, cheek pads and chin pads. The patient interface device is connected to a gas delivery tube or conduit and interfaces the ventilator or pressure support device with the airway of the patient, so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient. 
     It is known to maintain such patient interface devices on the face of a wearer by means of a headgear component having one or more straps adapted to fit over/around the patient&#39;s head and attached to the mask using removable mask connectors. Such headgear components provide a means for adjustment of the patient interface device for various head shapes and allow a user to easily don or remove the patient interface device. Despite the presence of the removable mask connectors, many patients pull mask component of their patient interface device forward to remove it, stretching the headgear in the process component. Although there are undoubtedly many reasons that people do this, they do it despite having headgear connectors available for easy release or disengagement from the mask shell. The stretching of the headgear often adversely affect the fit and/or adjustment of the patient interface device, and thus is problematic and undesirable. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a patient interface device that overcomes the shortcomings of conventional patient interface device. This object is achieved according to one embodiment of the present invention by providing a patient interface device that includes a cushion, a shell coupled to the cushion, a headgear having a first strap and a second strap, and a release mechanism coupled to the shell. The release mechanism includes a first cord coupled to the first strap and a second cord coupled to the second strap. The release mechanism is selectively moveable between a closed position and an open position. 
     In another embodiment, a method of using a patient interface device is provided that includes donning the patient interface device, wherein the patient interface device includes a cushion, a shell coupled to the cushion, a headgear having a first strap and a second strap, and a release mechanism coupled to the shell. The release mechanism includes a first cord coupled to the first strap and a second cord coupled to the second strap. The release mechanism is selectively moveable between a closed position and an open position. The method also includes adjusting a size of the headgear to a suitable size while the release mechanism is in the closed position and while the patient interface device is being worn, and placing the release mechanism into the open position and removing the patient interface device without further adjusting the size of the headgear. 
     In still another embodiment, a method of using a patient interface device is provided that includes choosing a particular non-adjustable headgear from among a plurality of differently sized non-adjustable headgears. The particular non-adjustable headgear includes a first strap and a second strap. The method further includes assembling the patient interface device by coupling the particular non-adjustable headgear to an assembly including a cushion, a shell coupled to the cushion, and a release mechanism coupled to the shell. The release mechanism includes a first cord coupled to the first strap and a second cord coupled to the second strap. The release mechanism is selectively moveable between a closed position and an open position. The method also includes donning the patient interface device while the release mechanism is in the open position, placing the release mechanism into the closed position, providing a breathing gas to the patient interface device while the patient interface device is being worn, placing the release mechanism into the open position and removing the patient interface device. 
     These and other objects, features, and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1-6  are schematic diagrams (showing front and isometric views) of a system adapted to provide a regimen of respiratory therapy to a patient according to one exemplary embodiment of the present invention in various stages of operation; 
         FIGS. 7 and 8  are front and rear plan views, respectively, of a first interlocking member forming a part of a quick release mechanism of the system of  FIGS. 1-6 ; 
         FIGS. 9 and 10  are front and rear plan views, respectively, of a second interlocking member forming a part of a quick release mechanism of the system of  FIGS. 1-6 ; 
         FIG. 11  is a schematic diagram of a system adapted to provide a regimen of respiratory therapy to a patient according to an alternative exemplary embodiment of the present invention; and 
         FIG. 12  is a schematic diagram of a system adapted to provide a regimen of respiratory therapy to a patient according to an alternative exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     As used herein, the singular form of “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. As used herein, the statement that two or more parts or components are “coupled” shall mean that the parts are joined or operate together either directly or indirectly, i.e., through one or more intermediate parts or components, so long as a link occurs. As used herein, “directly coupled” means that two elements are directly in contact with each other. As used herein, “fixedly coupled” or “fixed” means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other. 
     As used herein, the word “unitary” means a component is created as a single piece or unit. That is, a component that includes pieces that are created separately and then coupled together as a unit is not a “unitary” component or body. As employed herein, the statement that two or more parts or components “engage” one another shall mean that the parts exert a force against one another either directly or through one or more intermediate parts or components. As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality). 
     Directional phrases used herein, such as, for example and without limitation, top, bottom, left, right, upper, lower, front, back, and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein. 
     A system  2  adapted to provide a regimen of respiratory therapy to a patient according to one exemplary embodiment is generally shown in  FIGS. 1-6  in various stages of operation. System  2  includes a pressure generating device  4 , a patient circuit  6 , a patient interface device  8 , and an elbow conduit  10  having an exhaust port  12  provided therein. Although system  2  is discussed as including pressure generating device  4 , patient circuit  6 , patient interface device  8 , and elbow conduit  10 , it is contemplated that other systems may be employed while remaining within the scope of the present invention. For example, and without limitation, a system in which pressure generating device  4  is coupled to a patient interface device having an integrated exhaust port assembly is contemplated. 
     Pressure generating device  4  is structured to generate a flow of breathing gas and may include, without limitation, ventilators, constant pressure support devices (such as a continuous positive airway pressure device, or CPAP device), variable pressure devices (e.g., BiPAP®, Bi-Flex®, or C-Flex™ devices manufactured and distributed by Philips Respironics of Murrysville, Pa.), and auto-titration pressure support devices. Patient circuit  6  is structured to communicate the flow of breathing gas from pressure generating device  4  to patient interface device  8 . Patient interface  8  is typically a nasal or nasal/oral mask structured to be placed on and/or over the face of a patient. Any type of patient interface device  8 , however, which facilitates the delivery of the flow of breathing gas to, and the removal of a flow of exhalation gas from, the airway of such a patient may be used while remaining within the scope of the present invention. 
     In the illustrated embodiment, patient interface  8  includes a cushion  16 , a rigid shell  18 , and a forehead support  20 . Patient interface  8  also includes a headgear component  22  for securing patient interface device  8  to the patient&#39;s head. Headgear component  22  includes upper headgear straps  24 A,  24 B attached to shell  18  through slots  26 A,  26 B provided on opposite sides of forehead support  20 . Headgear component  22  also includes lower headgear straps  28 A,  28 B that are moveably coupled to opposite sides of the lower portion of shell  18  in the manner described in greater detail elsewhere herein as part of the quick release mechanism of the present invention. An opening in shell  18  to which elbow conduit  10  is coupled allows the flow of breathing gas from pressure generating device  4  to be communicated to an interior space defined by shell  18  and cushion  16 , and then, to the airway of a patient. The opening in shell  18  also allows the flow of exhalation gas (from the airway of such a patient) to be communicated to exhaust port  12  of elbow conduit  10  in the current embodiment. 
     Patient interface device  8  also includes a quick release mechanism  30  that allows headgear component  22  to be quickly and easily loosened and tightened to facilitate of donning and removal of patient interface device  8 . In the exemplary embodiment, quick release mechanism  30  allows headgear component  22  to be loosened and tightened by a patient with as little as one hand and eliminates the need for the removable headgear connectors that are present in many current patient interface devices. 
     Quick release mechanism  30  includes a first interlocking member  32 A and a second interlocking member  32 B. As seen in  FIGS. 7 and 8 , in the exemplary embodiment, first interlocking member  32 A is an elongated member that includes a circular base portion  34 A defining an aperture  36 A. An arm  38 A extends from base portion  34 A. A distal end  40 A of first interlocking member  32 A includes a protruding portion  42 A having a hole  44 A provided therein. The rear side of distal end  40 A ( FIG. 8 ) also includes a pin  46 . As seen in  FIGS. 9 and 10 , in the exemplary embodiment, second interlocking member  32 B is an elongated member that includes a circular base portion  34 B defining an aperture  36 B. An arm  38 B extends from base portion  34 B. A distal end  40 B of second interlocking member  32 B includes a protruding portion  42 B having a hole  44 B provided therein. The front side of distal end  40 B also includes a lead in feature  48  including a ramp  50  leading to a hole  52 . Together, pin  46  and lead in feature  48  including ramp  50 , and hole  52  provide a pin and pivot arrangement for selectively interlocking first interlocking member  32 A and second interlocking member  32 B as described in greater detail elsewhere herein. 
     As seen in  FIGS. 1-6 , first interlocking member  32 A and second interlocking member  32 B are rotatably mounted on shell  18  by first inserting a cylindrical coupling member or hub that protrudes from the surface of shell  18  and which is structured to be fluidly coupled to elbow conduit  10  through aperture  36 B of second interlocking member  32 B. The hub is then inserted through aperture  36 A of first interlocking member  32 A. When this is done, first interlocking member  32 A will rest on top of second interlocking member  32 B, and both first interlocking member  32 A and second interlocking member  32 B will be able to rotate freely about the longitudinal axis of the hub. The significance of this free rotation is explained below. 
     Elbow conduit  10  is then coupled to the hub by a friction fit and, in the illustrated embodiment, both first interlocking member  32 A and second interlocking member  32 B are held in place and kept form falling off by a flange  19  attached to elbow conduit  10 . In an alternative embodiment, the cylindrical hub includes four longitudinal slits around it outer circumference which enables the diameter thereof to be temporarily decreased by a compressive force so that the first interlocking member  32 A and second interlocking member  32 B can be slipped onto the hub. Thereafter, when the compressive force is removed, the hub will expand and the first interlocking member  32 A and second interlocking member  32 B will be prevented from falling off while still being able to rotate. Elbow conduit  10  in this embodiment may be provided with a similar split hub that is inserted into the shell hub and expands to hold it in place. Elbow conduit  10  may also be held in place by a split washer on the internal side of shell  18 . 
     Furthermore, in the exemplary embodiment, quick release mechanism  30  also includes a cord  54 A and a ring  56 A and cord  54 B and ring  56 B. As seen in  FIGS. 1-6 , the end of lower headgear strap  28 A is inserted through and coupled to ring  56 A. In addition, in the exemplary embodiment, a first end  60 A of cord  54 A is coupled to ring  56 A. Cord  54 A is then inserted through a hole  62 A provided on a first side of shell  18  (from the back of shell  18  toward the front of shell  18 ), passed upwardly along the front of shell  18 , inserted through hole  44 A of first interlocking member  32 A, passed downwardly along the front of shell  18 , and inserted back through a hole  63 A (from the front of shell  18  toward the back of shell  18 ). A second end  64 A of cord  54 A opposite first end  60 A is then attached to shell  18  at a location adjacent hole  63 A. Similarly, as seen in  FIGS. 1-3 , the end of lower headgear strap  28 B is inserted through and coupled to ring  56 B. In addition, in the exemplary embodiment, a first end  60 B of cord  54 B is coupled to ring  56 B. 
     Cord  54 B is then inserted through a hole  62 B provided on a second side of shell  18  (from the back of shell  18  toward the front of shell  18 ), passed upwardly along the front of shell  18 , inserted through hole  44 B of second interlocking member  32 B, passed downwardly along the front of shell  18 , and inserted back through a hole  63 B (from the front of shell  18  toward the back of shell  18 ). A second end  64 B of cord  54 B opposite first end  60 B is then attached to shell  18  at a location adjacent hole  63 B. Once these steps are performed, construction of quick release mechanism  30  is complete. 
     In an alternative embodiment, rather than cords  54 A,  54 B extending downwardly along the front of shell  18  and being inserted back through a holes  63 A,  63 B as in the illustrated embodiment, they are fixedly attached to distal ends  40 A,  40 B after being passed upwardly along the front of shell  18 . 
     In the exemplary, illustrated embodiment, cords  54 A,  54 B are inelastic, having essentially a fixed length. In an alternative embodiment, cords  54 A,  54 B may be elastic. 
     In operation, quick release mechanism  30  has two primary operating conditions/positions: (i) closed, and (ii) open. In the closed position, shown in  FIGS. 1  and  4 , first interlocking member  32 A and second interlocking member  32 B are vertically oriented and are interlocked to one another through operation of the pin and pivot arrangement described elsewhere herein. More specifically, in the closed position, pin  46  of first interlocking member  32 A is received within hole  52  after having been lead to hole  52  by ramp  50 . As shown in  FIG. 4 , in the closed position, the terminal end of each lower strap  28 A,  28 B is positioned no more than some predetermined minimum distance from shell  18 , and as a result a maximum tension is applied to cords  54 A,  54 B, which pulls lower headgear straps  28 A,  28 B to provide a maximum tension thereto and thus provide a snug fit for the patient. The closed position is the position that quick release mechanism  30  is to be in when patient interface device  8  is to be used for respiratory therapy. 
     To get to the open position, first interlocking member  32 A and second interlocking member  32 B are released from one another by disengaging the pin and pivot arrangement. In the exemplary embodiment, the patient is able to do so by pulling on distal end  40 A of first interlocking member  32 A (which is longer than second interlocking member  32 B), which releases pin  46  from hole  52 . Once released from one another, first interlocking member  32 A and second interlocking member  32 B are rotated downwardly as shown in  FIGS. 2 and 5  to the fully open position shown in  FIGS. 3 and 6 . In the exemplary, non-limiting embodiment, first interlocking member  32 A and second interlocking member  32 B are horizontally oriented in the fully open position. 
     As shown in  FIGS. 3 and 6 , in the fully open position, the tension on both cords  54 A,  54 B and on lower headgear straps  28 A,  28 B is released as a result of a portion of the length of cords  54 A,  54 B effectively being added to the length of lower headgear straps  28 A,  28 B. In the open position, the terminal end of each lower strap  28 A,  28 B is free to move beyond the predetermined minimum distance from shell  18 . The patient may then freely and easily remove patient interface device  8  without pulling on shell  18  or stretching headgear  22 . When the patient needs to don patient interface device  8  for therapy, the patient may place patient interface device  8  on his or her head with quick release mechanism  30  in the open position, position cushion  16  over his or her mouth and/or nose as appropriate, and then move quick release mechanism  30  to the closed position by rotating the first interlocking member  32 A and second interlocking member  32 B upwardly and interlocking them. When this is done, the lower headgear straps  28 A,  28 B will be pulled tight and headgear  22  will apply an appropriate, predetermined tension for an appropriate fit. 
     In the embodiment shown in  FIGS. 1-6 , the size of headgear component  22  is adjustable. In particular, the length of upper headgear straps  24 A,  24 B and lower headgear straps  28 A,  28 B is adjustable by any of a number of known methods. In the illustrated embodiment, headgear straps  24 A,  24 B and lower headgear straps  28 A,  28 B employ a hook and loop fastener system for this purpose wherein the exterior of each of the includes a loop fastener portion, and a corresponding hook fastener portion is provided on the exterior of each of end portions the straps. The strap may then be threaded through the associated ring or loop ( 26 ,  56 ) and then bent back on itself to adhere the hook fastener portion to the loop fastener portion when the desired length is achieved. Other suitable adjustment mechanisms such as, without limitation, a buckle arrangement commonly found on the straps of brassiere or a shoulder bag that allows the length of a strap to be adjusted may also be used. In this embodiment, the patient, a technician, or a patient and a technician together will preselect a suitable tension and fit for the patient interface device  8  while the quick release mechanism  30  is in the closed position ( FIGS. 1 and 4 ) by adjusting upper headgear straps  24 A,  24 B and/or lower headgear straps  28 A,  28 B. Once this suitable tension and fit is determined, thereafter the patient need not alter headgear component  22 , and instead may remove and don patient interface device  8  solely through operation of quick release mechanism  30 . 
       FIGS. 11 and 12  show systems  2 ′ and  2 ″, respectively, adapted to provide a regimen of respiratory therapy to a patient according to alternative embodiments of the present invention that include headgear components that are not freely adjustable (i.e., while lower headgear straps thereof may or may not stretch to an extent due to the material of which they are made, they are not provided with a mechanism that allows their length to be selectively adjusted). Systems  2 ′ and  2 ″ include many of the same components as system  2  described above, and thus like components are labeled with like reference numerals. Most notably, systems  2 ′ and  2 ″ each include a quick release mechanism  30  essentially as described elsewhere herein. 
     Referring to  FIG. 11 , system  2 ′ includes a patient interface  8 ′ having a headgear component  22 ′ for securing patient interface device  8 ′ to the patient&#39;s head. Headgear component  22 ′ includes upper headgear straps  24 A′,  24 B′, lower headgear strap  28 A′ and a similar opposite lower headgear strap that is not shown, all of which are not freely adjustable in length as described above. Button elements  66 A and  66 B, each including a including a shaft and a cap, are provided are opposite sides of forehead support  20 . A clip element  68 A having a slot  70 A and an arm  72 A having an orifice  74 A is attached to the end of upper headgear strap  24 A′. Clip element  68 A is made of a flexible material such that the portion thereof defining orifice  74 A is structured to deform to pass over the cap of button element  66 A and revert substantially to its original shape around and adjacent the shaft of button element  66 A in order to connect clip element  68 A to button element  66 A and thus upper headgear strap  24 A′ to forehead support  20 . Operation of clip element  68 B to couple to button element  66 A and thus connect upper headgear strap  24 B′ to forehead support  20  is similar. 
     Also referring to  FIG. 11 , first end  60 A of cord  54 A is connected to a headgear connector member  76 A having a button element  78 A including a shaft  80  and a cap  82 . A clip element  84 A having a slot  86 A and an arm  88 A having an orifice  90 A is attached to the end of lower headgear strap  28 A′. Clip element  84 A is made of a flexible material such that the portion thereof defining orifice  90 A is structured to deform to pass over cap  82  of button element  78 A and revert substantially to its original shape around and adjacent  80  shaft of button element  78 A in order to connect clip element  84 A to button element  78 A and thus lower headgear strap  28 A′ to headgear connector member  76 A and cord  54 A. A similar headgear connector member and clip element are provided for connecting the other, opposite lower headgear strap to cord  54 B. 
     Referring to  FIG. 12 , system  2 ″ includes a patient interface  8 ″ having a headgear component  22 ″ for securing patient interface device  8 ″ to the patient&#39;s head. Headgear component  22 ″ includes upper headgear straps  24 A″,  24 B″, lower headgear strap  28 A″ and a similar opposite lower headgear strap that is not shown, all of which are not freely adjustable in length as described above. Socket elements  92 A and  92 B are provided are opposite sides of forehead support  20 . A clip element  94 A having a slot  96 A and ball  98 A is attached to the end of upper headgear strap  24 A″. Ball  98 A is structured to be received within socket element  92 A in order to connect clip element  94 A, and thus upper headgear strap  24 A″, to forehead support  20 . Operation of clip element  94 B to couple to button element  66 A and thus connect upper headgear strap  24 B″ to forehead support  20  is similar. 
     Also referring to  FIG. 12 , first end  60 A of cord  54 A is connected to a headgear connector member  100 A having a socket element  102 A. A clip element  104 A having a slot  106 A and ball  108 A is attached to the end of lower headgear strap  28 A″. Ball  108 A is structured to be received within socket element  102 A in order to connect clip element  104 A to socket element  102 A and thus lower headgear strap  28 A″ to headgear connector member  100 A and cord  54 A. A similar headgear connector member and clip element are provided for connecting the other, opposite lower headgear strap to cord  54 B. 
     In the embodiments of  FIGS. 11 and 12 , a technician, or a patient and a technician together will preselect a suitable tension and fit for the patient interface device  8 ′,  8 ″ while the quick release mechanism  30  is in the closed position by selecting an appropriately sized headgear component  22 ′,  22 ″ from a number of differently sized non-adjustable headgear components  22 ′,  22 ″. Patients altering the size of a headgear determined to be appropriate for a patient by a technician can be problematic, as the altered size may adversely affect therapy. Thus, this embodiment is advantageous in that, once the size is selected, it cannot be altered by the patient. 
     It can be further appreciated that the present invention provides a mechanism that facilitates the removal and reattachment of a patient interface device while reducing the likelihood of stretching of the headgear component in the process. 
     In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” or “including” does not exclude the presence of elements or steps other than those listed in a claim. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. In any device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain elements are recited in mutually different dependent claims does not indicate that these elements cannot be used in combination. 
     Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.