Abstract:
The invention relates to an applicator for a nasal cannula, comprising a body ( 11 ) enclosing a hollow space ( 22 ). The applicator further comprises tube connections ( 20, 21 ) for supplying a respirable gas into the hollow space ( 22 ). The applicator further comprises prongs ( 18, 19 ) for administering the respirable gas into the nostrils of a person. A valve ( 15, 16, 17, 38, 42 ) is located in a wall of the body ( 11 ) so that respirable gas can flow from the outside through the valve into the hollow space ( 22 ), but not in the reverse direction. The invention further relates to an applicator having a top of sealing cones ( 23, 24 ), wherein the sealing cones ( 23, 24 ) may be provided with rim-shaped sealing lips on their side facing away from the body ( 11 ), which produce a tight seal with the inner wall of the respective nostril.

Description:
FIELD OF THE INVENTION 
       [0001]    The field of the invention relates to applicators for nasal cannulae of the type defined in the preambles of the independent patent claims. 
         [0002]    The invention relates to the field of nasal cannulae, which are used for pneumatically splinting the respiratory tract. 
       DISCUSSION OF RELATED ART 
       [0003]    In the CPAP therapy (Continuous Positive Airway Pressure Therapy) a patient is supplied via a nose mask with a continuous positive airway pressure relative to the ambient air pressure. This positive airway pressure, if chosen appropriately, ensures that the upper respiratory tract remains completely opened during the whole night, so that no obstructive respiratory disorders occur. One also talks about pneumatically splinting the respiratory tract. The necessary positive airway pressure depends, inter alia, on the sleep phase and the position of the body of the sleeping person. In order to limit the positive airway pressure, which is perceived as unpleasant, to the necessary amount a therapy apparatus (AutoCPAP) is disclosed in WO 02/083221 A2, which adjusts the positive airway pressure automatically, thereby adapting it to the sleep phase and the position of the body. 
         [0004]    In order to facilitate the breathing, moreover, BiPAP apparatus and multilevel apparatus have been developed. These apparatus have the property to support the patient&#39;s breathing by reducing the positive airway pressure as he is exhaling and by increasing the positive airway pressure again as he is inhaling. That is, these apparatus work with at least two pressure levels. Such apparatus are known, for instance, from DE 691 32 030 T2 and WO 02/26283 A2. 
         [0005]    Furthermore, oxygen nasal cannulae for the oxygen treatment are known from the prior art. By means of the oxygen nasal cannula air at an increased oxygen partial pressure (&gt;210 mbar) or pure oxygen is administered into the patient&#39;s nose. An oxygen treatment is carried out, for instance, in case of an acute or chronic hypoxemia resulting from a respiratory or cardiovascular disorder (myocardial infarction, shock) or certain intoxications caused, for instance, by carbon monoxide, carbon dioxide, coal gas or smoke. 
         [0006]    The use of oxygen nasal cannulae in an anti-snore apparatus is known from WO 02/062413 A2. In this context oxygen nasal cannulae are designated as nasal cannulae. WO 02/062413 A2 further discloses nasal cannulae having integrated jet pumps, which are illustrated in FIGS. 4 and 5 of 02/062413 A2. 
         [0007]    US 2003/0079749 A1 and WO 2006/072231 A2 describe nasal cannulae whose nose pieces have rounded edges. The air sweeps past these edges, thereby largely avoiding hissing and whistling noises. 
         [0008]    FR 2 827 778 discloses an apparatus which is designated as a monolithic part and resembles the nose part of a nasal cannula. The apparatus serves to support a patient&#39;s respiration without or with insufficient spontaneous respiration through the nostrils. The dimensions are adapted to premature infants. Distal, tubular elements project into the nostrils. Foamed discs around the tubular elements serve as a resilient stop. In another embodiment the tubular elements are placed in two dome-shaped sleeves which are connected by a bridge on the side of the sleeves facing away from the nose. Two ducts are supplied with a respirable gas in parallel. A capillary tube serves as a pressure probe. At the beginning of an inspiration phase a supply device receives through the capillary tube a pressure drop and can supply the patient with a continuous or pulse-shaped jet of respirable gas. After an inspiration phase the supply device is instructed by the pressure transmitted through the capillary tube to stop the gas supply. Thus, the patient is able to freely exhale. 
       SUMMARY OF THE INVENTION 
       [0009]    It is the object of the invention to provide improved applicators for nasal cannulae. 
         [0010]    This object is achieved with the teaching of the independent claims. 
         [0011]    Preferred embodiments of the invention are defined in the dependent claims. 
         [0012]    A valve in a wall of the body of the applicator, with the valve allowing gas only from the ambiance to flow into the body of the applicator, has the surprising advantage that the user is not exposed to the risk of suffocating if the connected compressor is defective. 
         [0013]    A top slipped over the prongs can adapt the outer shape of the prongs in a surprisingly simple fashion to the inner shape of the nostrils of a patient. Thus, merely the small, relatively simply shaped top has a patient-specific shape, and not the large nasal cannula whose shape is relatively complicated. Hence, greater quantities of the nasal cannula and, thus, a reduction of costs are achieved. 
         [0014]    A bridge between the two sealing cones of the top on their side facing the body ( 11 ) prevents a single sealing cone from getting lost. Furthermore, in a surprisingly simple fashion, the sealing cones are prevented from turning out of position on the prongs. Finally, the bridge also prevents the top from unintentionally getting pulled off from the prongs. 
         [0015]    Rim-shaped sealing lips on the side of the sealing cones facing away from the body of the applicator produce a comfortable tight connection with the inner wall of the respective nostril. 
         [0016]    As the sealing cones are partially hollow between an inner part and an outer cone so as to allow a gas flow between the inner part ( 31 ,  32 ) and the respective outer cone ( 33 ,  34 ) parallel to the inner part ( 31 ,  32 ), the additional air resistance in the nostril is kept small by the applicator. 
         [0017]    It is an advantage of the membrane-loaded outlets on the body-sided end of the outer cones that the user does not inhale again the exhaled, used air. Moreover, the choice of the rigidity of the shim-shaped membranes allows an adjustment of the positive airway pressure produced by the applicator, which facilitates the control of the connected compressor. 
         [0018]    The collar on the nose-sided end of the prongs advantageously prevents the top from unintentionally getting pulled off. 
         [0019]    The cover permits a simple mounting of the flexible membrane. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    A preferred embodiment of the invention with reference to the accompanying drawings shall be explained in more detail below. In the drawings: 
           [0021]      FIG. 1  shows a front view of an applicator according to the invention; 
           [0022]      FIG. 2  shows a top view of an applicator according to the invention; 
           [0023]      FIG. 3  shows a rear view of an applicator according to the invention; 
           [0024]      FIG. 4  shows a bottom view of an applicator according to the invention; 
           [0025]      FIG. 5  shows the front view of  FIG. 1  without top and cover; 
           [0026]      FIG. 6  shows the bottom view of  FIG. 4  without top and cover; and 
           [0027]      FIG. 7  shows the bottom view of  FIG. 6  without membranes. 
       
    
    
     LIST OF REFERENCE NUMBERS 
       [0000]    
       
           1  applicator 
           11  body 
           12  top 
           13 ,  14  membrane 
           15  cover 
           16 ,  17  membrane 
           18 ,  19  prong 
           20 ,  21  tube connection 
           22  hollow space 
           23 ,  24  sealing cone 
           25 ,  26 ,  27 ,  28  sealing lip 
           29  bridge 
           30  rib 
           31 ,  32  inner cylinder 
           33 ,  34  outer cone 
           35 ,  36  collar 
           37  oblong hole 
           38  aperture 
           39  groove 
           40 ,  41  frusto-conical prolongation 
           42  braces 
       
     
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0049]      FIG. 1  shows a front view of the applicator  1  according to the invention. The applicator  1  is mainly formed of a body  11  that is connected to a compressor by two tube connections  20 ,  21  via a non-illustrated tube loop. The body  11  has two prongs  18 ,  19  over which a top  12  has been slipped. The top  12  is substantially comprised of two sealing cones  23 ,  24 . Synonyms or equivalents of a compressor are a pump, a compressed air source, a supply device or a blower. In  FIG. 1  substantially only the collars  35 ,  36  of the prongs  18 ,  19  can be seen. The prongs  18 ,  19  without the sealing cones  23 ,  24  are shown in  FIG. 5 . 
         [0050]    The sealing cones according to  FIG. 1  are adapted to the inner shape of the nostrils of a user at the top, i.e. on their nose-sided end away from the body. The sealing cones are, in fact, slightly smaller than the openings of the user&#39;s nostrils. This small gap is bridged and sealed by sealing lips  25 ,  26 ,  27  and  28 . The sealing lips  25 ,  26 ,  27  and  28  themselves have approximately the shape of a circumferential surface of a very flat cone. This means that they extend from the inward top to the outward bottom. As a result of this shape the sealing cones can be easily introduced into the nose and represent a small resistance to prevent the applicator from slipping out of the nose. 
         [0051]    The sealing cones  23 ,  24  are connected to each other on their lower end, which is away from the nose and close to the body, by a bridge  29  in order to prevent the sealing cones  23 ,  24  from being pulled off from the prongs  18 ,  19  too easily and to prevent the sealing cones  23 ,  24  from being turned out of position relative to the body  11  and the user&#39;s nostrils. 
         [0052]    On the side of the body  11  opposite the prongs  18 , 19  the body  11  is provided with an oblong hole  37 , which is easy to recognize in  FIGS. 6 and 7 . The oblong hole  37  is sealed by a cover  15  which forms two valves together with the membranes  16 ,  17  (see  FIG. 4 ). The cover has a circumferential groove  39  on its outer edge, which engages with the wall of body  11  that limits the oblong hole  37 . Hence, the cover  15  is clamped relative to the wall of body  11  and seals the oblong hole  37  in a gas-tight manner. 
         [0053]    The body  11  encloses a hollow space  22 . Especially the inner surfaces of the body  11  do not have any sharp edges. Rather are all edges rounded off so as to minimize flow noises. As the wall of the body  11  has approximately the same thickness these rounded portions can also be seen on the outside of body  11 . 
         [0054]      FIG. 2  shows a top view of an applicator according to the invention. It can be recognized that the sealing cones  23 ,  24  are comprised of outer cones  33  and  34 , inner cylinders  31  and  32  and ribs  30  mechanically connecting the outer cones  33 ,  34  to the inner cylinders  31 ,  32 . The outer surfaces of the prongs  18 ,  19  are approximately cylindrical and define a fit with the inner surfaces of the inner cylinders  31 ,  32 . 
         [0055]    In operation respirable gas compressed by a compressor flows from the tube connections  20 ,  21  through the hollow space  22  through the prongs  18 ,  19  into the nose of a user. Vice versa, exhaled air flows through the sealing cones  23 ,  24 , i.e. between the inner cylinders  31 ,  32  and the outer cones  33 ,  34  past the ribs  30 , through slightly downwardly bent membranes  13  and  14  to the outside. This means that the user practically no longer inhales any exhaled air. 
         [0056]    As shown in  FIG. 1 , the outer cones  33 ,  34  end slightly above the body  11 , while the inner cylinders  31 ,  32  come up to the body  11 . The openings between the inner cylinders  31 ,  32  and the outer cones  33 ,  34  are sealed by the membranes  13 ,  14 . However, if there is a certain positive airway pressure between the inner cylinders  31 ,  32  and the outer cones  33 ,  34 , as is the case during exhaling, the membranes  13 ,  14  are bent slightly downwardly so that exhaled air can escape to the atmosphere. The administered positive airway pressure can be adjusted by means of the hardness of the membranes  13 ,  14  and the size of the membranes  13 ,  14  together with the size of the body-sided outlets of the sealing cones  23 ,  24 . The inner cylinders  31 ,  32  have at least one step which presses the membranes  13 ,  14  against the outer cones  33 ,  34 . In another embodiment the inner cylinders  31 ,  32  may also be provided with grooves which fix the vertical positions of the membranes relative to the outer cones  33 ,  34 . 
         [0057]      FIG. 3  shows a rear view of an applicator according to the invention. 
         [0058]      FIG. 4  shows a bottom view of an applicator according to the invention. In this view one can recognize the two valves in the cover  15 . The cover  15  has two round cavities each partially closed by a cross. Between the braces  42  of the cross four approximately quadrant-shaped apertures  38  remain in the cover  15 . The apertures  38  are sealed from inside by the flexible membranes  16 ,  17  so that air can enter the hollow space  22  from the outside, while it cannot escape from inside out of the hollow space  22  through the apertures  38  to the outside.  FIG. 6  shows the same view as  FIG. 4 , however, without illustrating the cover  15 , so that the membranes  16 ,  17  seem to float in the air. The two valves allow a user to inhale even if no respirable gas is supplied through the tube connections  20 ,  21  in the event of a failure of the compressor. 
         [0059]    The two membranes  16 ,  17  each have a frusto-conical prolongation  40  and  41  in the center which projects towards the viewer in  FIGS. 4 and 6 . The frusto-conical prolongations are connected to the actual membranes by cylindrical sections. The cylindrical sections have a diameter smaller than the largest diameters of the frusto-conical prolongations, so that a groove is defined between each frusto-conical prolongation and the respective membrane. This groove rests in a central hole in the braces  42  of the crosses in the cavities of the cover  15 . 
         [0060]      FIG. 5  shows a view similar to that of  FIG. 1 , however, without illustrating the top  12  with the sealing cones  23 ,  24  and the cover  15 . That is, the cylindrical prongs  18 ,  19 , the collars  35 ,  36  as well as the membranes  13 ,  14  are easier to recognize. On the bottom side, the frusto-conical prolongations  40 ,  41  of the membranes  16 ,  17  project out of the oblong hole  37 . 
         [0061]      FIG. 7  shows a view similar to that of  FIG. 6 , however, without illustrating the membranes  16  and  17 . In this view, the oblong hole  37  allows a sight through the hollow space  22  to the inside of the rounded junctions between the prongs  18 ,  19  and the rest of the body  11 . On the inside the radius of the rounded portion is approximately as large as the inner diameter of the prongs  18 ,  19 . One can see in  FIG. 5  that the radius of this rounded portion on the outside is approximately half as large as on the inside. That is because the wall thickness in the region of the prongs  18 ,  19  is approximately half the size as in the rest of the body  11 . 
         [0062]    In can be recognized in  FIGS. 2 ,  4 ,  6  and  7  that the body is substantially broader than the tube connections  20 ,  21 . Apart from the purpose of providing space for the cover  15  and the valves located in the cover  15  this measure also has the purpose of reducing the flow velocity of the gas in the junction region between the prongs  18 ,  19  and the body  11  by enlarging the cross-section, thereby reducing flow noises. 
         [0063]    The invention was explained in more detail by means of preferred embodiments above. A person skilled in the art will appreciate, however, that various alterations and modifications may be made without departing from the spirit of the invention. Therefore, the scope of protection will be defined by the following claims and their equivalents.