Abstract:
A pressurized air delivery device, system and method provide respiratory assistance to individuals, particularly infant humans. The device having nasal conduits or prongs which are in fluid communication with respective supply conduits separately supply each nasal conduit with a breathable gas such as air or oxygen. The size of the nasal conduits or prongs may be chosen according to the size of the individual&#39;s nares and the spacing between nasal conduits or prongs may be adjustable.

Description:
FIELD OF THE INVENTION 
       [0001]    THIS INVENTION relates to delivery of continuous positive airway pressure to an individual, such as an infant, to thereby provide respiratory assistance. 
       BACKGROUND 
       [0002]    Newborn, infants particularly those born premature often have a need for respiratory support, ranging from increased ambient oxygen, through continuous positive airways pressure (CPAP) and endotracheal ventilation to, rarely, extracorporeal membrane oxygenation (ECMO). Infants born before 30 weeks of completed gestation almost invariably need a period of CPAP or ventilation to survive. 
         [0003]    The commonest reason for premature newborn infants to require respiratory support is due to a lack of surfactant, a protein which helps to keep the smallest of the lungs air spaces open. Treatment for this disease process has consisted of CPAP since it was realised in the mid 1970&#39;s that CPAP treatment greatly improved infants rates of survival. 
         [0004]    Whilst replacement of surfactant via an endotracheal tube has been available in Australia since the early 1990&#39;s, this requires infants to be intubated and ventilated. However intubation and ventilation, itself, can damage infants&#39; lungs and there has been a shift in the last 5-10 years towards CPAP, both as a modality of support post extubation and a primary support in its own right, for the majority of infants with respiratory distress. 
         [0005]    CPAP may be delivered via a multitude of machine—patient interfaces. The best devices utilise “short binasal” prongs designed to snugly fit into the nares of infants, thereby allowing the pressure to be delivered to the infant whilst minimising the resistance of the device to the infants&#39; work of breathing. 
         [0006]    Current “short binasal” prongs are designed with a connection between the two prongs which insert into the infants nose. This connection may cause pressure an the nasal septum, which in extreme cases can lead to necrosis and require plastic surgery to correct. This problem is exacerbated by the mechanism by which these prongs are fixed to the infants head and face by means of hats, bonnets or headbands and the relatively bulky tubing and prongs in use. 
         [0007]    Although the currently available devices come in a variety of sizes, both for prong size and separation between the prongs, each prong set is typically of a fixed prong size and separation. 
         [0008]    Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application. 
       SUMMARY 
       [0009]    The invention is broadly directed to providing respiratory assistance to an individual, typically an infant, by way of a device, system and/or method that delivers pressurized air to the nares of the individual, to alleviate one or more of the aforementioned deficiencies of the prior art. 
         [0010]    In one aspect, the invention provides a pressurized air delivery device for providing respiratory assistance to an individual, said device comprising a plurality of nasal conduits in fluid communication with respective supply conduits connectable to a source of pressurized, breathable gas. 
         [0011]    In another aspect, the invention provides a pressurized air delivery system for providing respiratory assistance to an individual, said system comprising a plurality of flexible nasal conduits in fluid communication with respective supply conduits connected to a source of pressurized, breathable gas. 
         [0012]    In yet another aspect, the invention provides a method of providing respiratory assistance to an individual, said method including the step of delivering pressurized air to the nose of said individual through a plurality of nasal conduits in fluid communication with respective supply conduits connected to a source of pressurized, breathable gas. 
         [0013]    Preferably, according to the aforementioned aspects, the individual is an infant human. 
         [0014]    Suitably, continuous positive airway pressure is delivered to an individual by way of a plurality of conduits respectively locatable in the nares of an individual, without engaging, bearing against or otherwise contacting the nasal septum. Advantageously, continuous positive airway pressure is delivered to the individual without providing a hat, bonnet, headband or other separate means for attachment to the individual. 
         [0015]    In a preferred embodiment, the nasal conduits are of a size adapted to fit the nares of the individual. In a particularly preferred embodiment the nasal conduits are interchangeable in size. 
         [0016]    Preferably the nasal conduits are formed of a material that is more rigid than the supply conduits. 
         [0017]    In certain embodiments, the nasal conduits may each comprise an inlet and an outlet, said outlet facilitating exhaust of exhaled gas to atmosphere. 
         [0018]    Preferably, the nasal conduits further comprise respective valves to control oxygen flow to the user. 
         [0019]    Suitably, the device and/or system further comprises a spacer to maintain a desired spacing or distance between the nasal conduits. 
         [0020]    Preferably, the spacer is adjustable in order to select a desired spacing or distance between the nasal conduits. 
         [0021]    In one preferred embodiment, said respective nasal prongs are maintained at a desired distance apart by an adjustable spacer that comprises a sliding rod or a band that comprises teeth or serrations. Typically, the adjustable spacer comprises an adjustment member, such as a lever, ratchet, turnbuckle, or cam, although without limitation thereto. 
         [0022]    In a particularly preferred embodiment, the spaces comprises a band comprising teeth, ridges or serrations releasably engageable by a cam or lever. 
         [0023]    Throughout this specification, unless the context requires otherwise, the words “comprise”, “comprises” and “comprising” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    A preferred embodiment of the invention will now be described by way of example only, with reference to the accompanying figures in which: 
           [0025]      FIG. 1  shows an embodiment where nasal prongs being held at a desired distance apart by rare earth magnets; 
           [0026]      FIG. 2  shows an embodiment where nasal prongs are held at a desired distance apart by a ratchet mechanism; 
           [0027]      FIG. 3  shows an embodiment where nasal prongs are held at a desired distance apart by a turnbuckle system; 
           [0028]      FIG. 4  shows an embodiment where nasal prongs are spaced apart by a sliding rod mechanism; 
           [0029]      FIG. 5  shows side and top views of different sized nasal prongs spaced apart by a sliding rod mechanism; 
           [0030]      FIG. 6  shows side and top views of different sized prongs spaced apart by a sliding locking flat band mechanism; 
           [0031]      FIG. 7  shows nasal prongs spaced apart by a sliding locking flat band mechanism that is adjustable by a cam mechanism; 
           [0032]      FIG. 8  shows an example of the attachment of nasal prongs to an air supply conduit; and 
           [0033]      FIG. 9  shows a nasal prong comprising and inlet and outlet for exhalation. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Referring to  FIG. 1 , device  10  comprises respective nasal conduits  20 A,  20 B in fluid communication with respective air and/or oxygen supply conduits  30 A,  30 B. Nasal conduits  20 A,  20 B respectively comprise arms  21 A,  21 B normal to air supply conduits  30 A,  30 B and elbows  22 A,  22 B which respectively terminate in nasal prongs  23 A,  23 B. Preferably nasal conduits  20 A,  20 B are formed of a material that is more rigid (e.g. polymethylmethacrylate or polycarbonate) than the supply conduits which are of a relatively flexible tubing material (e.g. polyurethane). 
         [0035]    In use, air and/or oxygen supply conduits  30 A,  30 B are connected to a source of pressurized air, oxygen or other gas suitable for assisting human respiration (not shown). The direction of pressurized air flow from the source is indicated by solid arrows. 
         [0036]    According to this embodiment, spacer  40  comprises magnetic poles  41 A,  41 B on bridge  42 , which respectively interact with magnetic poles  24 A,  24 B on nasal prongs  23 A,  23 B to maintain nasal prongs  23 A,  23 B at a desired separation. Typically, although not exclusively, magnetic poles  41 A,  41 B,  24 A and  24 B are produced by rare earth magnets (e.g. lanthanides such as neodymium or samarium, although without limitation thereto) located on the outside of the nares. 
         [0037]    Referring to an embodiment shown in  FIG. 2 , device  110  comprises spacer  140  comprising adjustable ratchet  142  which maintains nasal prongs  123 A,  123 B at a desired separation. 
         [0038]    An embodiment shown in  FIG. 3  shows nasal prongs  223 A,  223 B adjustably movable (indicated by solid horizontal arrows) to a desired distance apart by spacer  240  comprising turnbuckle  243  that is adjustable by winding wheel  244  in either direction (indicated by solid arrows). 
         [0039]    In another embodiment of device  310  shown in  FIG. 4 , nasal prongs  323 A,  323 B are held at a desired distance apart by spacer  340  that is adjustable by way of sliding rod mechanism  345  that is adjustable by pushing button  346  to release sliding rod  347  and thereby finding the correct distance between nasal prongs  323 A,  323 B. 
         [0040]    Referring now to  FIG. 5 , an embodiment of device  410  is shown similar to that shown in  FIG. 4 , wherein nasal prongs  423 A,  423 B are of reduced diameter compared to those in  FIG. 4 , demonstrating that nasal prongs  23 A,  23 B may be of varying, interchangeable sizes. 
         [0041]      FIG. 6  shows an embodiment where nasal prongs  523 A,  523 B are held at a desired distance apart by spacer  540  comprising slidable band  548  that comprises teeth, serrations or ridges  1548  releasably engageable by lever  549 . Lever  549  engages teeth, serrations or ridges  1548  of flat band  548  to releasably maintain the desired distance between prongs  523 A,  523 B and thereby allow adjustment of the spacing between prongs  523 A,  523 B. Preferably, slidable band  548  is located underneath arms  521 A,  521 B of nasal conduits  520 A,  520 B (relative to an individual&#39;s nares) to maximize the distance between slidable band  548  and the individual&#39;s nasal septum. This should eliminate or at least minimize any potential contact between slidable flat band  548  and the individual&#39;s nasal septum. 
         [0042]    In an embodiment shown in  FIG. 7 , nasal prongs  623 A,  623 B are held at an appropriate distance apart by spacer  640  comprising slidable t band  648  that comprises teeth, serrations or ridges  1648  releasably engageable by cam  650 . Cam  650  releasably engages teeth, serrations or ridges  1648  of slidable band  648  to releasably maintain the desired distance between prongs  623 A,  623 B and thereby allow adjustment of the spacing between prongs  623 A,  623 B. As in the embodiment described in  FIG. 6 , slidable band  648  is ideally located underneath arms  621 A,  621 B of nasal conduits  620 A,  620 B (relative to an individual&#39;s nares) to maximize the distance between slidable band  648  and the individual&#39;s nasal septum. 
         [0043]    It should also be appreciated that slidable band  540 ,  640  is shown as a “flat” band in  FIGS. 6 and 7 . However, in certain embodiments slidable band  540 ,  640  may be curved to facilitate a more comfortable fit on the individual. 
         [0044]      FIG. 8  shows an example of one way in which nasal conduit  720 A is attached to air supply conduit  730 A. In this example, arm  721 A is pushed onto air supply conduit  730 A and barbs  770 A,  770 B are employed to hold arm  721 A in place on air supply conduit  730 A. 
         [0045]    Referring to  FIG. 9 , there is shown an embodiment wherein device  810  comprises nasal prong  823  having inlet  870  and outlet  880 , which each operate as “one-way” valves. Inlet  870  comprises leaflet  871  which moves between open position  872  and closed position  873  to enable a one-way flow of air to the nares. Outlet  880  comprises leaflet  881  which moves between closed position  882  and open position  883  to enable a one-way flow of exhaled gas from the nares to atmosphere via aperture  884 . Screen  890  may also be provided to prevent accidental inhalation of leaflets  871  and/or  881 . 
         [0046]    It will be appreciated the present invention provides continuous positive airway pressure to an individual, typically an infant human, without engaging or otherwise contacting the nasal septum in a manner that causes irritation or discomfort to the user. Air, oxygen or other breathable gas is supplied via separate air supply conduits and nasal conduits, rather than via a common air supply conduit into separate nasal conduits. This eliminates the portion of the common air supply conduit that contacts and irritates the nasal septum. Furthermore, the nasal prongs may be provided in a variety of interchangeably different sizes to suit the size of the nares of the user, which also assists the objective of reducing the level of irritation and discomfort. 
         [0047]    Another advantage of the present invention is that the device needs limited fixation, (even just a piece of tape may suffice) rather than the bonnets, hats, head-bands etc. required with prior art devices. Furthermore, many prior art devices require significant nursing expertise to attach and supervise in use. The present invention can be fitted and supervised by any person familiar with standard nasal cannulae. 
         [0048]    In summary, the present invention provides improved nasal septal protection, ease of attachment, ease of nursing care, reduced weight and bulk, the ability to adapt nasal conduit size to different nare sizes (sometimes if a child has been nasally intubated, one nare is larger than the other), and variable separation between respective conduits. 
         [0049]    Throughout this specification, the aim has been to describe the preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.