Abstract:
A back strap for a patient interface device having a headgear component including a first strap member and a second strap member attached to the first strap member and structured to wraparound a back of the patient&#39;s head. The back strap member includes a first portion having a first attachment mechanism structured to couple the first portion to the second strap member, a connecting portion extending from the first portion, and a second portion having a second attachment mechanism structured to couple the second portion to at least one of the first strap member, a patient sealing assembly, or skin, hair, neck or clothing of the patient in a manner wherein the back strap member is configured to hold the second strap member and prevent it from riding up on a head of the patient during use.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application claims the priority benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/902,406 filed on Nov. 11, 2013, the contents of which are herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention pertains to patient interface devices structured to deliver a flow of breathing gas to a patient, and, in particular, to patient interface devices employing a headgear component having a modular back strap to improve performance. 
         [0004]    2. Description of the Related Art 
         [0005]    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 into the patient&#39;s 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 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. 
         [0006]    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 sealing cushion on the face of the patient. The mask component may be, without limitation, a nasal mask that covers the patient&#39;s nose, a nasal/oral mask that covers the patient&#39;s nose and mouth, a nasal cushion that rests beneath the patient&#39;s nose (such as a “pillows” style nasal cushion having nasal prongs that are received within the patient&#39;s nares or a “cradle” style nasal cushion that rests beneath and covers the patient&#39;s nares), 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. 
         [0007]    It is known to maintain such devices on the face of a wearer by a headgear having one or more straps adapted to fit over/around the patient&#39;s head. One popular patient interface device  2  is shown in  FIGS. 1 and 2 . As seen in  FIGS. 1 and 2 , patient interface device  2  includes a nasal mask  4  for providing a seal and delivering a breathing gas to the patient&#39;s airway, and a headgear apparatus  6  for securing patient interface device  2  to the patient&#39;s head. Headgear apparatus  6  includes a first strap  8  that extends from nasal mask  4  at the patient&#39;s nose to the crown of the patient&#39;s head and a second strap  10  which attaches to first strap  8  above the ear and wraps around the back of the patient&#39;s head/neck. 
         [0008]    Patient interface devices like patient interface device  2  are extremely appealing to patients due to their minimal size and straps. Because of this, patients will very often initially choose a device of this type, but will experience problems with second strap  10  riding up on the back of the head while they are asleep. Such riding often results in patient interface device  2 , and in particular nasal mask  4 , becoming dislodged from the face as shown in  FIG. 2 . In many cases, the patient will then request a new patient interface device with a different headgear configuration. This costs the supplier a new patient interface device and requires someone, such as a respiratory therapist, to take time to fit the patient with a completely different device. 
         [0009]    In addition, the forces applied to nasal mask  4  by this type of headgear apparatus may be less than optimal because nasal cushions such as nasal cushion  4  typically work better when the forces applied to the nose bridge and upper lip can be adjusted independently to achieve proper cushion orientation with respect to the face. Having another strap for the mask  4  is adventitious not only for the initial adjustment, but it also aids in helping stabilize the mask while the patient is sleeping. Without the addition of a stabilization strap the mask could become dislodged during sleep thus causing interruptions to therapy delivery. 
       SUMMARY OF THE INVENTION 
       [0010]    In one embodiment, a back strap is provided for a patient interface device having a headgear component including a first strap member and a second strap member attached to the first strap member and structured to wrap around a back of the patient&#39;s head. The back strap member includes a first portion having a first attachment mechanism structured to couple the first portion to the second strap member, a connecting portion extending from the first portion, and a second portion having a second attachment mechanism structured to couple the second portion to at least one of the first strap member, a patient sealing assembly (the faceplate or cushion thereof) or the skin, hair, neck or clothing of the patient in a manner wherein the back strap member is configured to hold the second strap member and prevent it from riding up on a head of the patient during use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIGS. 1 and 2  are schematic diagrams of a prior art patient interface device including a prior art headgear; 
           [0012]      FIGS. 3 and 4  are schematic diagrams of a system adapted to provide a regimen of respiratory therapy to a patient according to one exemplary embodiment; 
           [0013]      FIG. 5  is a front elevational view of a back strap member according to the exemplary embodiment forming a part of a patient interface device of the system of  FIGS. 3 and 4 ; 
           [0014]      FIG. 6  is a schematic diagram of a system adapted to provide a regimen of respiratory therapy to a patient according to an alternative exemplary embodiment 
           [0015]      FIGS. 7 and 8  are schematic diagrams of a system adapted to provide a regimen of respiratory therapy to a patient according to another alternative exemplary embodiment; 
           [0016]      FIG. 9  is a front elevational view of a back strap member according to another exemplary embodiment forming a part of a patient interface device of the system of  FIGS. 7 and 8 ; 
           [0017]      FIGS. 10 and 11  are schematic diagrams of a system adapted to provide a regimen of respiratory therapy to a patient according to yet another alternative exemplary embodiment; 
           [0018]      FIG. 12  is a front elevational view and  FIG. 13  is a rear elevational view of a back strap member according to another exemplary embodiment forming a part of a patient interface device of the system of  FIGS. 10 and 11 ; 
           [0019]      FIGS. 14 and 15  are schematic diagrams of a system adapted to provide a regimen of respiratory therapy to a patient according to still another alternative exemplary embodiment; 
           [0020]      FIG. 16  is a front elevational view of a back strap member according to another exemplary embodiment forming a part of a patient interface device of the system of  FIGS. 14 and 15 ; and 
           [0021]      FIG. 17  is a schematic diagram of a system adapted to provide a regimen of respiratory therapy to a patient according to an alternative exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0022]    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. 
         [0023]    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). 
         [0024]    As used herein, the term “textile” shall mean a material consisting of a network of interlaced or otherwise entangled natural or artificial fibers made by, for example and without limitation, weaving, knitting, spreading, crocheting, or bonding (e.g., by chemical, mechanical, heat or solvent treatment) the fibers to form the network, and may include, for example, and without limitation, woven and nonwoven fabric materials. 
         [0025]    As used herein, the term “foam” shall mean a substance that is formed by trapping pockets of gas or compressible particles in a solid material, and may include closed-cell foams wherein the gas forms discrete pockets each completely surrounded by the solid material, and open-cell foams, wherein the gas pockets connect with each other. 
         [0026]    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. 
         [0027]    A system  12  adapted to provide a regimen of respiratory therapy to a patient according to one exemplary embodiment is generally shown in  FIGS. 3 and 4 . System  12  includes a pressure generating device  14 , a delivery conduit  16 , and a patient interface device  18  having a fluid coupling conduit  20 . Pressure generating device  14  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. Delivery conduit  16  is structured to communicate the flow of breathing gas from pressure generating device  14  to patient interface device  18  through fluid coupling conduit  20 , which in the illustrated embodiment is an elbow connector. Delivery conduit  16  and patient interface device  18  are often collectively referred to as a patient circuit. 
         [0028]    In the exemplary embodiment, patient interface device  18  includes a patient sealing assembly  22 , which in the illustrated embodiment is a nasal mask. However, other types of patient sealing assemblies, such as, without limitation, a nasal/oral mask, a nasal cushion, or a full face mask, which facilitate the delivery of the flow of breathing gas to the airway of a patient, may be substituted for patient sealing assembly  22  while remaining within the scope of the present invention. Patient sealing assembly  22  includes a cushion member  24  coupled to a faceplate member  26 . In the illustrated embodiment, cushion member  24  is defined from a unitary piece of soft, flexible, cushiony, elastomeric material, such as, without limitation, silicone, an appropriately soft thermoplastic elastomer, a closed cell foam, or any combination of such materials. Also in the illustrated embodiment, faceplate member  26  is made of a rigid or semi-rigid material, such as, without limitation, an injection molded thermoplastic or silicone. An opening in faceplate member  26 , to which fluid coupling conduit  20  is coupled, allows the flow of breathing gas from pressure generating device  14  to be communicated to an interior space defined by cushion member  24 , and then to the airway of a patient. 
         [0029]    Patient interface device  18  also includes a headgear component  28  for securing patient interface device  18  to the patient&#39;s head. Headgear component  28  includes a first strap member  30  that extends from each side of faceplate member  26  at the patient&#39;s nose to the crown of the patient&#39;s head and a second strap member  32  which attaches to first strap member  30  above the ear and wraps around the back of the patient&#39;s head/neck. In one exemplary embodiment, first strap member  30  is made of a semi-rigid material such as, without limitation, silicone or another suitable polymer. In an alternative exemplary embodiment, first strap member  30  is made of a more flexible material, such as, without limitation, a foam laminate material that includes: (i) a middle foam layer made of, for example, a resiliently stretchable open-celled polyurethane foam, (ii) an outer textile layer made of, for example, a resiliently stretchable loop fabric, such as a blend of nylon and spandex, and (iii) an inner textile layer made of, for example, a resiliently stretchable wicking fabric, such as a blend of polyester and spandex. 
         [0030]    Also in the exemplary embodiment, second strap member  32  is made of a foam laminate material as just described and attaches to first strap member  30  by a hook and loop fastening system provided thereon. In particular, each end of second strap member  32  may be threaded through respective looped portions  34  provided on opposites sides of first strap member  30  and then be bent back on itself in order to adhere the hook fastener portion to the loop fastener portion and thereby adjustably connect second strap member  32  to first strap member  30 . It will be understood that the described hook and loop fastening arrangement is meant to be exemplary only, and that other selectively adjustable fastening arrangements, such as snaps, buttons, adhesive, etc., are also possible within the scope of the present invention. 
         [0031]    In addition, headgear component  28  further includes a back strap member  36  that, as seen in  FIGS. 3 and 4 , is structured to run under the ears of the patient from each end of first strap member  30  and connect to second strap member  32  at the back of the head/neck.  FIG. 5  is a front elevational view of back strap member  36  according to the exemplary embodiment. As seen in  FIG. 5 , back strap member  36  includes a central portion  38  having a tab member  40  extending therefrom. The front surface of tab member  40  is provided with a hook pad  42 . Back strap member  36  also includes first and second side strap members  44 A and  44 B that extend from opposite sides of central portion  38 . In the exemplary embodiment, first and second side strap members  44 A and  44 B each have an arcuate shape. The front surface of each of first and second side strap members  44 A and  44 B is provided with a respective hook pad  46 A,  46 B. 
         [0032]    In the exemplary embodiment, back strap member  36  is made of a foam laminate material as described elsewhere herein. It will be understood, however, that this is meant to be exemplary only and that other materials may also be used, such as fabric, silicone (or another rubber-like material), a thermoplastic, or some combination thereof. 
         [0033]    In operation, back strap member  36  is attached to and made part of headgear component  28  by threading tab member  40  under second strap member  32  and then bending tab member  40  back on itself in order to adhere hook pad  42  to a loop fastener portion provided on the front surface thereof, which in the exemplary embodiment is provided by the outer textile layer of the foam laminate (e.g., a resiliently stretchable loop fabric). First and second side strap members  44 A and  44 B are then each threaded under an end of first strap member  30  adjacent patient sealing assembly  22  and then bent back on itself in order to adhere hook pad  46 A,  46 B to a loop fastener portion provided on the front surface thereof, which in the exemplary embodiment is provided by the outer textile layer of the foam laminate (e.g., a resiliently stretchable loop fabric). When so attached, back strap member  36  will hold second strap member  32  in place and prevent it from moving/riding up on the back of the head while the patient sleeps. In addition, it will be understood that the described hook and loop fastening arrangement is meant to be exemplary only, and that other selectively adjustable fastening arrangements, such as snaps, buttons, adhesive, etc., are also possible within the scope of the present invention. 
         [0034]      FIG. 17  is a schematic diagram of an alternative system  12 ′ adapted to provide a regimen of respiratory therapy to a patient that is similar to system  12 . System  12 ′, however, employs an alternative headgear component  28 ′ wherein second strap member  32  has a slit  33  provided therein through which tab member  40  may be threaded as shown in  FIG. 17 . A main benefit of having slit  33  is that it will prevent movement of tab member  40  across the back of the head. 
         [0035]      FIG. 6  is a schematic diagram of a system  48  adapted to provide a regimen of respiratory therapy to a patient according to an alternative exemplary embodiment. System  48  is similar to system  12 , and like components are labeled with like reference numerals. However, as seen in  FIG. 6 , system  48  includes an alternative patient interface device  50  wherein first and second side strap members  44 A and  44 B of back strap member  36 , rather than being threaded under an end of first strap member  30 , are instead directly attached to respective loop member  52  provided on and extending from faceplate member  26  (or, alternatively, cushion member  24 ). This configuration is advantageous since it provides additional sealing forces to the cushion member  24 . 
         [0036]      FIGS. 7 and 8  are side and rear schematic diagrams of a system  54  adapted to provide a regimen of respiratory therapy to a patient according to a further alternative exemplary embodiment. System  54  is similar to system  12 , and like components are labeled with like reference numerals. However, system  54  includes an alternative patient interface device  56  that employs an alternative headgear component  58 . As seen in  FIGS. 7 and 8 , headgear component  58  is similar to headgear component  28  as it includes first strap member  30  and second strap member  32 . However, headgear component  58  includes an alternative back strap member  60  described below to hold second strap member  32  in place and prevent it from moving/riding up on the back of the head while the patient sleeps. 
         [0037]      FIG. 9  is a front elevational view of back strap member  60  according to the exemplary embodiment. Back strap member  60  includes a top attaching portion  62 , a bottom attaching portion  64  and a connecting portion  66  provided in between top attaching portion  62  and bottom attaching portion  64 . In the exemplary embodiment, back strap member  60  is made of a foam laminate material as described elsewhere herein. It will be understood, however, that this is meant to be exemplary only and that other materials may also be used, such as fabric, silicone (or another rubber-like material), a thermoplastic, or some combination thereof. In addition, as seen in  FIG. 9 , the front surface of top attaching portion  62  is provided with a hook pad  68 , and the front surface of bottom attaching portion  64  is provided with an adhesive pad  70  made of an adhesive material such as silicone gel or polyurethane gel. 
         [0038]    In operation, back strap member  60  is attached to and made part of headgear component  58  by coupling hook pad  68  to a loop fastener portion provided on second strap member  32 , which in the exemplary embodiment is provided by the outer textile layer of the foam laminate (e.g., a resiliently stretchable loop fabric). It will be understood, however, that the described hook and loop fastening arrangement is meant to be exemplary only, and that other selectively adjustable fastening arrangements, such as snaps, buttons, adhesive, etc., are also possible within the scope of the present invention. Adhesive pad  70  is then releasably attached to the hair, skin and/or clothing of the patient as shown in  FIGS. 7 and 8 . When so attached, back strap member  60  will hold second strap member  32  in place and prevent it from moving/riding up on the back of the head while the patient sleeps. 
         [0039]      FIGS. 10 and 11  are side and rear schematic diagrams of a system  72  adapted to provide a regimen of respiratory therapy to a patient according to still a further alternative exemplary embodiment. System  72  is similar to system  12 , and like components are labeled with like reference numerals. However, system  72  includes an alternative patient interface device  74  that employs another alternative headgear component  76 . As seen in  FIGS. 10 and 11 , headgear component  76  is similar to headgear component  28  as it includes first strap member  30  and second strap member  32 . However, headgear component  76 , includes an alternative back strap member  78  described below to hold second strap member  32  in place and prevent it from moving/riding up on the back of the head while the patient sleeps. 
         [0040]      FIG. 12  is a front elevational view and  FIG. 13  is a rear elevational view of back strap member  78  according to the exemplary embodiment. Back strap member  78  includes a top attaching portion  80 , a bottom attaching portion  82 , and a connecting portion  84  provided in between top attaching portion  80  and bottom attaching portion  82 . In the exemplary embodiment, back strap member  78  is made of a foam laminate material as described elsewhere herein. It will be understood, however, that this is meant to be exemplary only and that other materials may also be used, such as fabric, silicone (or another rubber-like material), a thermoplastic, or some combination thereof. In addition, as seen in  FIG. 12 , the front surface of top attaching portion  80  is provided with a hook pad  86 , and the rear surface of bottom attaching portion  82  is provided with a hook pad  88 . 
         [0041]    Headgear component  76  further includes a clip member  90  having a biased portion  92  structured to be selectively connected to the patient&#39;s clothing, and a looped portion  94  extending from biased portion  92 . 
         [0042]    In operation, back strap member  78  is attached to and made part of headgear component  76  by coupling hook pad  86  to a loop fastener portion provided on second strap member  32 , which in the exemplary embodiment is provided by the outer textile layer of the foam laminate (e.g., a resiliently stretchable loop fabric). Bottom attaching portion  82  is then inserted through looped portion and bent back on itself as shown in  FIGS. 7 and 8  to attach hook pad  88  to a loop fastener portion provided on the surface thereof. When so attached, back strap member  78  will hold second strap member  32  in place and prevent it from moving/riding up on the back of the head while the patient sleeps. Further, it will be understood that the described hook and loop fastening arrangement is meant to be exemplary only, and that other selectively adjustable fastening arrangements, such as snaps, buttons, adhesive, etc., are also possible within the scope of the present invention. 
         [0043]      FIGS. 14 and 15  are side and rear schematic diagrams of a system  90  adapted to provide a regimen of respiratory therapy to a patient according to another further alternative exemplary embodiment. System  90  is similar to system  12 , and like components are labeled with like reference numerals. However, system  90  includes yet another alternative patient interface device  92  that employs yet another alternative headgear component  90 . As seen in  FIGS. 14 and 15 , headgear component  94  is similar to headgear component  28  as it includes first strap member  30  and second strap member  32 . However, headgear component  94  includes another alternative back strap member  96  described below to hold second strap member  32  in place and prevent it from moving/riding up on the back of the head while the patient sleeps. 
         [0044]      FIG. 16  is a front elevational view of back strap member  96  according to the exemplary embodiment. Back strap member  96  includes a top attaching portion  98 , bottom attaching straps  100 A and  100 B, and a connecting portion  102  provided in between top attaching portion  98  and bottom attaching straps  100 A and  100 B. In the exemplary embodiment, back strap member  96  is made of a foam laminate material as described elsewhere herein. It will be understood, however, that this is meant to be exemplary only and that other materials may also be used, such as fabric, silicone (or another rubber-like material), a thermoplastic, or some combination thereof. In addition, as seen in  FIG. 16 , the front surface of top attaching portion  98  is provided with a hook pad  104 , and the end of the front surface of bottom attaching strap  100 B is provided with a hook pad  106 . 
         [0045]    In operation, back strap member  96  is attached to and made part of headgear component  94  by coupling hook pad  98  to a loop fastener portion provided on second strap member  32 , which in the exemplary embodiment is provided by the outer textile layer of the foam laminate (e.g., a resiliently stretchable loop fabric). Bottom attaching straps  100 A and  100 B are then wrapped around the neck of the patient as shown in  FIGS. 14 and 15  and hook pad  106  is attached to a loop fastener portion of bottom attaching strap  100 A, which in the exemplary embodiment is provided by the outer textile layer of the foam laminate (e.g., a resiliently stretchable loop fabric). When so attached, back strap member  96  will hold second strap member  32  in place and prevent it from moving/riding up on the back of the head while the patient sleeps. It will be understood that the described hook and loop fastening arrangement is meant to be exemplary only, and that other selectively adjustable fastening arrangements, such as snaps, buttons, adhesive, etc., are also possible within the scope of the present invention. 
         [0046]    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. 
         [0047]    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.