Abstract:
Disclosed is a respiratory mask comprising a mask body and an articulated connection piece that can be connected to a respiratory tube. On the mask body, at least one exhalation gap is located in the vicinity of a connection that holds the articulated connection piece. Preferably, the exhalation gap terminates in an umbrella-shaped outflow channel that runs away from the patient. Preferably, at least two components of the respiratory mask are interconnected without play.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of U.S. patent application Ser. No. 11/883,822, the entire disclosure of which is expressly incorporated by reference herein, which is a National Stage of International Patent Application PCT/DE2005/001535, filed Sep. 1, 2005, which claims priority under 35 U.S.C. §119 of German patent application 10 2004 043 208.2, filed Sep. 3, 2004. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention concerns a respiratory mask with a mask body and an articulated connector that can be connected with a respiratory hose. 
         [0004]    2. Description of the Related Art 
         [0005]    Respiratory masks are used, for example, in connection with ventilators to carry respiratory gas to the patient and to help carry away exhaled respiratory gas. The respiratory mask is typically connected with the ventilator by the respiratory hose. 
         [0006]    A disadvantage of previously known respiratory masks is that the exhalation of the patient through the mask body and the respiratory hose causes an acoustic effect that is unpleasant for the patient and persons in the vicinity. In addition, the exhaled stream of air produces a cool draft that brushes along the patient&#39;s skin. 
         [0007]    The objective of the present invention is to create a comfortable design of a respiratory mask that largely eliminates these unpleasant effects on the patient by the exhaled air. 
         [0008]    In accordance with the invention, the solution to this problem is characterized by the fact that at least one exhalation gap is located in the vicinity of the mask body, preferably in the vicinity of a connection on the mask body that receives the articulated connector. 
       SUMMARY OF THE INVENTION 
       [0009]    The respiratory mask of the invention, which is to be understood not only as a single part but rather as an element of a complete ventilator, comprises a mask body and an articulated connector that can be connected with a respiratory hose, such that at least one exhalation gap is located in the vicinity of the transition between the articulated connector and a connection on the mask body that receives the articulated connector. In particular, the arrangement of the exhalation gap between the mask body and the connector keeps the noise level low compared to other positions in which it could be arranged. In this position of the exhalation gap, CO.sub.2 is also washed out especially effectively. Moreover, it is precisely in the area of transition between the mask body and the connector that it is possible to provide a large gap length, which is acoustically especially advantageous compared, for example, to holes and short slots. 
         [0010]    The one or more exhalation gaps are preferably bounded by two outflow surfaces each. 
         [0011]    The articulated connector is advantageously designed as a ball-and-socket joint and is supported on individual points, especially on two points, in a ball cage of the receiving connection. In this way, there is a slight amount of bearing friction, and easy mobility of the attached respiratory hose is guaranteed. Tolerances can also be compensated in a simple way. 
         [0012]    In another advantageous embodiment of the respiratory mask, the one or more respiratory gaps are bounded by the outflow surfaces, such that they are located adjacent to at least one spacing element and in this regard are play-free or can even be provided with pretensioning relative to each other. This prevents the occurrence of undesired vibrations and resonances due to escaping air when play is present, for especially in an exhalation gap in a ball-and-socket joint, a large gap length is obtained. Under certain circumstances, this could prove acoustically unfavorable if moving parts are present in the gap. 
         [0013]    In addition, the exhalation gap between two outflow surfaces can be produced largely tolerance-free if the surfaces forming the gap are pressed against each other by a pretensioning force, thus eliminating any play between them, and the height of the gap is adjusted by spacing elements between the surfaces. In a design of this type, the height of the gap depends, apart from the shape and positional tolerances of the surfaces that form the gap, only on the tolerance of the height of a rib used as a spacing element. Since typical rib heights in exhalation gaps are 0.1-0.5 mm, gap tolerances of ±0.005 mm or less can be produced with a high degree of process reliability. Consequently, flow and sound emissions can be maintained within very narrow limits. 
         [0014]    The mask body and the connector are preferably joined with a mechanical coding system. This has the advantage of preventing incorrect attachment of the mask body and connector to each other and of preventing an incorrect combination of a connector with a mask body. 
         [0015]    It is advantageous for the body of the mask and the connector to be attached to each other by a retaining ring with a locking device, for example, a bayonet catch. The retaining ring also serves to fix the exhalation gaps, for example, by pretensioning the outflow surfaces of the respiratory mask and complementary outflow surfaces on the retaining ring against each other. 
         [0016]    In another advantageous embodiment of the respiratory mask, the outflow surfaces form an outflow channel, which carries away the respiratory gas flow at an angle of 10-45°, especially 20-30° and especially preferably about 25° to a plane arranged frontally with respect to the face of the patient. In this way, the exhaled air is carried away from the patient in a basically umbrella-shaped path and is not unpleasantly perceived by the patient. 
         [0017]    In addition, the outflow channel can be designed in such a way that it prevents the flow of exhaled air from moving in the general direction of the patient&#39;s eyes, since a draft of air towards the eyes is felt as especially unpleasant. 
         [0018]    Furthermore, the respiratory mask can be designed in such a way that surfaces of the mask that bound the outflow channel are made of hard plastic, and surfaces of elements of the respiratory mask that are handled are made of soft plastic. In this way, on the one hand, the flow of respiratory gas is reliably carried away, and, on the other hand, the ease of handling and operating the respiratory mask is improved. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention is explained below with reference to the examples illustrated in the figures. 
           [0020]      FIG. 1  shows a perspective view of a respiratory mask designed as a nasal mask. 
           [0021]      FIG. 2  shows a view of the inside of the mask, as seen from the rear of  FIG. 1 . 
           [0022]      FIG. 3  shows a view of the outside of the mask, as seen from the front of  FIG. 1 . 
           [0023]      FIG. 4  shows a perspective view of the body of the mask in  FIG. 1 . 
           [0024]      FIG. 5  shows a side view of the body of the mask. 
           [0025]      FIG. 6  shows a cross section through the plane of symmetry of the body of the mask. 
           [0026]      FIG. 7  shows a view of the retaining ring from the rear. 
           [0027]      FIG. 8  shows a view of the retaining ring from the front. 
           [0028]      FIG. 9  shows a perspective view of the retaining ring. 
           [0029]      FIG. 10  shows a side view of the retaining ring. 
           [0030]      FIG. 11  shows a cross-sectional view of the retaining ring from  FIG. 10 . 
           [0031]      FIG. 12  shows a perspective view of the body of the mask. 
           [0032]      FIG. 13  shows a partial view of an enlarged cross section through the body of the mask in the vicinity of the ball-and-socket joint. 
           [0033]      FIG. 14  shows an enlarged view of the detail XIV in  FIG. 13 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]      FIG. 1  shows a respiratory mask that is designed as a nasal mask. The body  1  of the mask is made of a relatively strong material. The mask has a protruding edge  2 , which rests against the face of a patient (not shown) and provides the necessary seal. An angled connector  3  connects the body  1  of the mask with a rotatably supported sleeve  4 , which is used to attach a respiratory gas hose (not shown). To guarantee secure positioning of the respiratory mask on the patient&#39;s head, a forehead support  5  is used. The connector  3  and the mask body  1  are connected with each other by a ball-and-socket joint  18 . 
         [0035]      FIG. 2  shows the interior of the nasal mask from  FIG. 1  in a direction of view from the inside towards a receptacle for the ball-and-socket joint  18 , which is not shown in this drawing. Two pressure measurement connectors  9  are located in the upper area. Flow openings  7  lead to exhalation gaps  14  (not shown in this drawing). The flow openings  7  are bounded by flow guide structures  8 , which are designed in such a way that they cause the respiratory gas flow to converge and to be guided into the exhalation gaps  14 . The flow guide structures  8  are preferably designed in such a way that the respiratory gas flow is guided in funnel-like fashion into the exhalation gaps  14 . The flow guide structures  8  in the upper region block the flow of respiratory gas in the direction of the patient&#39;s eyes. Inclined surfaces  6  are provided to facilitate the insertion of bayonet teeth  26  of a ball cage  24 , which is not shown in this drawing. 
         [0036]      FIG. 3  shows the view of the outside of the mask from  FIG. 1 , as seen from the front of the mask. An outflow surface  10  is formed as a ring. A retaining ring  31 , which is not shown in this drawing, can be mounted and locked in place with the aid of ribs  11  and a catch  12 . 
         [0037]      FIG. 4  shows a perspective view of the body of the nasal mask. A centering ring  13  is provided for mounting the retaining ring. Exhalation gaps  14  are located on the sides of the centering ring  13  and open towards the outflow surface  10 . The centering ring  13  has recesses  15  that act as a mechanical coding system to prevent incorrect mounting of the retaining ring. 
         [0038]      FIG. 5  shows a side view of the body of the mask. The mask body  1 , the centering ring  13 , and the catch  12  are especially apparent in this view. 
         [0039]      FIG. 6  shows a cross section through the body of the mask from  FIG. 5 . The respiratory gas flow  17  moves along the flow guide structure  8  and into the exhalation gap  14 . The flow guide structure  8  is preferably designed in such a way that the respiratory gas flow is guided in funnel-like fashion into the exhalation gap  14 . The exhalation gap is bounded by the flow guide surface  16 . In the exhalation gap, the respiratory gas flow is deflected at least once on the flow guide surface  16 . Deflection of the respiratory gas flow can take place only in the exhalation gap  14 , only in the area of transition of the mask body  1  into the exhalation gap  14 , or combined in both areas. 
         [0040]    The respiratory gas flow moves from inside the respiratory mask to outside the mask along the flow guide surface  16 . After leaving the exhalation gap  14 , which is the narrowest point, the respiratory gas flow leaves the respiratory mask in a fan-shaped flow path along the extended outflow surface  10 . In this regard, the respiratory gas flow leaves the exhalation gap  14  at an angle alpha, which is preferably 10-45° to the vertical in  FIG. 6 . This vertical plane coincides with a plane that runs frontally to the face of a patient (not shown here). 
         [0041]      FIG. 7  shows a top view of a retaining ring  31  from the rear. It has a width d of less than 7 mm, as indicated by a double arrow. Spacer ribs  25  allow the retaining ring  31  to be mounted on the mask body  1  in the vicinity of the outflow surface  10  without play and with pretension. In the assembled state, the exhalation gap  14  is bounded by outflow surfaces  28  on the retaining ring  31  and the outflow surface  10  on the body  1  of the mask. A tab  20  on the retaining ring  31  is the complement to the catch  12  on the body  1  of the mask, so that additional securing of the retaining ring  31  on the body  1  of the mask is ensured. A surface segment  19  that rests on the outflow surface  10  in the assembled state guarantees that no air can flow off in the direction of the patient&#39;s eyes. Slots  29  between the elements of the ball cage  24  allow easy assembly. 
         [0042]      FIG. 8  shows a view of the retaining ring  31  from the front. The inner region of the retaining ring  31  is made of a hard material  23 , and the outer region is made of a soft material  22 . Nubs  21  improve the grip. 
         [0043]      FIG. 9  shows the retaining ring  31  in a rear perspective view. This viewing direction reveals the receptacle  30  for the web of the centering ring  13 . 
         [0044]      FIG. 10  shows a side view of the retaining ring  31  and provides a view of the bayonet teeth  26 . 
         [0045]      FIG. 11  shows a cross-sectional view of the retaining ring  31  from  FIG. 10 . 
         [0046]    The functions of the individual components illustrated in  FIG. 9  to  FIG. 11  will be explained again in detail later in connection with a description of the assembly and disassembly of the individual components for the specific purpose of further clarifying the mechanical significance and functionality of the individual components. 
         [0047]    The perspective view in  FIG. 12  again illustrates the mask body  1  after removal of the forehead support  5 , which is not shown in  FIG. 12 . In the transition region between the outflow surface  10  and the centering ring  13 , especially the location of the exhalation gap  14  is once again evident. The exhalation gaps  14  have essentially rectangular cross-sectional shapes, and their longitudinal axes extend in the circumferential direction of the outflow surface  10 . The individual exhalation gaps  14  are separated from each other by spacing elements  32 . The spacing elements  32  bring about a mechanical connection between the centering ring  13  and the other material of the body  1  of the mask. 
         [0048]    The exhalation gaps  14  are preferably arranged in such a way that they extend in a region of the centering ring  13  that faces the outflow surface  10 . In this way, the respiratory gas emerging from the exhalation gaps  14  is guided directly into the area of the outflow surface  10 . After leaving  t he exhalation gaps  14 , the respiratory gas flow is deflected on the wide and extended outflow surfaces  10 ,  28  and flows diffusely and quietly into the surrounding environment through the outflow channel defined by the outflow surfaces. 
         [0049]      FIG. 13  shows an enlarged partial cross-sectional view in the area of transition between the ball-and-socket joint  18  and the retaining ring  31  held by the mask body  1 . An arched course of the ball cage  24  is especially evident. The ball cage  24  extends concavely with a stronger curvature than a convexly shaped outer surface of the ball-and-socket joint  18 . In this way, the ball-and-socket joint  18  is acted upon only along two guide lines, guide points  33 ,  34 , or along linear segments of the ball cage  24 . This makes it possible to compensate any production tolerances that may be present in the vicinity of the surfaces of the ball-and-socket joint  18  and/or the ball cage  24 , since there is no surface guidance of the components on each other. Spring tensioning of the ball-and-socket joint  18  inside the ball cage  24  is preferably provided, so that secure support of the ball-and-socket joint  18  along the guide lines  33 ,  34  is guaranteed. 
         [0050]      FIG. 14  shows an enlarged section of the passage of the respiratory gas flow through the exhalation gap  14  along the flow guide surface  16  to the surrounding environment see  FIG. 6 . The respiratory gas flow  17  enters the exhalation gap  14 , for example, in funnel-like fashion. The exhalation gap is bounded by the flow guide surface  16 . In the exhalation gap, the respiratory gas flow is deflected at least once on the flow guide surface  16 . The respiratory gas flow is guided from the inside of the respiratory mask to the outside along the flow guide surface  16 . During the passage of the respiratory gas flow through the exhalation gap  14  along the flow guide surface  16  to the surrounding environment, the respiratory gas flow is deflected at an angle beta (β), which is preferably arranged 1-15° to a vertical line  38 . This vertical line stands essentially at an angle of 90° perpendicularly to the plane formed by the parts of the body of the mask that bound the exhalation gap. During the passage of the respiratory gas flow through the exhalation gap  14  along the flow guide surface  16  to the surrounding environment, it is especially preferred for the respiratory gas flow to be deflected at an angle beta (β) arranged 2-7° to a vertical line  38 . 
         [0051]    To provide further explanation of the function of the individual components, we shall now explain the assembly of the individual parts, starting from their unassembled state. This assembly can also be easily managed by the patient himself. In a first step, the mask body  1 , which is made of the harder material, and the protruding edge  2  of the mask are fitted together. To this end, the protruding edge  2  of the mask has a U-shaped profile that is not evident in the drawings. This U-shaped profile is pushed onto an edge of the body  1  of the mask. In the area of the point of contact between the protruding edge of the mask and the body of the mask, there is at least one undercut and at least one projection complementary to the undercut. The undercut is preferably located in the area of the softer component. The interaction of the undercut and projection in the assembled state provides a secure connection. 
         [0052]    In the next assembly step, for example, a shaft  35  of the forehead support  2  can be inserted in a mounting support  36  of the mask body  1  and secured by means of at least one fastening device  37 . However, the assembly of the forehead support  5  can also be carried out at any other desired point of the assembly operation. 
         [0053]    In another assembly step, the retaining ring  31  is pushed onto the connector  3 , starting from the sleeve  4 , and is positioned in the area of the ball-and-socket joint  18 . As the retaining ring  31  is being pushed onto the connector  3 , it has an orientation such that, after the placement operation has been completed, the bayonet teeth  26  point in the direction away from the sleeve  4 , and the ball-and-socket joint  18  is partially enclosed by the ball cage  24  of the retaining ring  31 . 
         [0054]    In a final assembly step, the retaining ring  31  is positioned, together with the connector  3 , in the vicinity of the centering ring  13  of the body  1  of the mask. Due to the asymmetrical arrangement of the ribs  11  along the periphery, as shown, for example, in  FIG. 3 , and the corresponding arrangement of the bayonet teeth  26 , the bayonet teeth  26  can be inserted in the recesses  37  between the ribs  11  only in a single predetermined position. This creates a mechanical coding system. 
         [0055]    After the bayonet teeth  26  have been inserted in the recesses  37  between the ribs  11 , the retaining ring  31  is twisted relative to the body  1  of the mask in such a way that the catch  12  is engaged. The catch  12  is preferably designed as a projection of the retaining ring  31  that engages a corresponding recess in the mask body  1 . In principle, however, the device can also be constructed in the opposite way. Elastic engagement of the catch  12  is assisted if the retaining ring  31  is made of a relatively soft material, so that the likewise soft projection of the retaining ring  31  can be inserted in the recess of the mask body  1  and can also be twisted back out again. 
         [0056]    After the retaining ring  31  has been twisted relative to the mask body  1 , the assembly operation is complete. The final position of the retaining ring  31  is predetermined by a lateral stop of the bayonet teeth  26  on the ribs  11 . In addition, the bayonet teeth  26  engage behind the ribs  11 , so that the total unit is also able to withstand tensile loads. The respiratory mask is disassembled in the reverse order of assembly described above. 
         [0057]    As a result of the design of the retaining ring  31 , it can be mounted on the mask body  1  without play and, if necessary, with pretensioning. Consequently, the width of the exhalation gap or gaps  14  now depends only on the tolerance of the height of the spacer ribs  25 . The exhalation gap  14  is thus realized in a way that is extremely uniform and largely independent of tolerance. This in turn means that the discharge of the respiratory gas through the exhalation gap  14  is extremely constant and thus that the sound emissions produced by this discharge are likewise extremely constant. 
         [0058]    The design of the retaining ring  31  allows the ball-and-socket joint  18  to be inserted in the elastic ball cage  24  of the retaining ring  31  and allows the ball cage  24  to enclose the ball-and-socket joint  18  at least partially. The ball-and-socket joint  18  is secured in the ball cage  24  by inserting the centering ring  13  in the receptacle  30  present in the retaining ring  31 . As a result, the elastic elements of the ball cage  24  are bounded on one side by the ball-and-socket joint  18  and on the other side by the centering ring  13 . In the assembled state, the ball-and-socket joint is secured in the area of the mask in this way. The mobility of the ball-and-socket joint, on the one hand, and the seal relative to the respiratory gas in the area between the ball-and-socket and-socket joint and the ball cage, on the other hand, are determined by the exact dimensioning and narrow tolerances.