Abstract:
A larynx mask ( 1 ) includes a cover plate ( 12 ) having a peripheral cull ( 13 ) adjoining thereon and is provided with a tube insertion connector ( 11 ) at the proximal end, while the tip ( 4 ) has a special design at the distal end. The cover plate  12  ends in the region of the tip on the cuff, or even before that, and the esophageal passage ( 18 ) runs as an open channel ( 20 ) over a constricted region ( 13 ′) of the cuff ( 13 ). Said channel preferably includes a widening ( 22 ) and is delimited on both sides by reinforcement means ( 21 ), which are preferably formed by reinforcing walls ( 21 ′) or additionally as reinforcing ribs ( 21 ″). Said design of the lead-through of the esophageal passage results in a considerable reinforcement of the proximal tip of the larynx mask and therefore counteracts possible kinking of the tip ( 4 ).

Description:
This application is the US national phase entry of International Patent Application no. PCT/CH2009/000373, filed Nov. 20, 2009, which claims priority to Swiss patent application no. 1859/08 filed Nov. 27, 2008. 
     FIELD OF THE INVENTION 
     The present invention relates to a larynx mask, suitable for insertion through the middle of the pharynx via the epiglottis, comprising a cover plate with a tube insertion connector, a respiration lumen opening and an oesophageal passage as well as an inflatable cuff peripherally surrounding the cover plate on the ventral side. 
     BACKGROUND 
     Larynx masks are supplied with supraglottic tubes which are inserted into the pharynx of a patient to keep the airways open and to ventilate the patient. By means of the supraglottic tube a larynx mask is inserted through the middle of the pharynx via the epiglottis into the lower pharynx and positioned behind or around the larynx. Such larynx masks are used to ventilate a patient while he/she is anaesthetised. They also allow the introduction of tubes, probes, optical instruments and other instruments into the airways. More and more frequently such larynx masks have oesophageal access. This allows the introduction of probes into the oesophagus and the stomach in order to remove gastric juices and other fluids as well as air from the stomach. In anaesthetised patients emptying of the stomach is intended to prevent the stomach contents flowing back into the upper respiratory tract and being aspirated into the unprotected airways (windpipe, bronchi and lungs). A further advantage of an oesophageal access is the removal of passively or actively regurgitated stomach contents from the upper oesophagus to outside, which thereby represents limited, and thus inadequate, aspiration protection. However, these larynx masks do not allow the removal of fluids from the pharynx. 
     A large number of different larynx masks are known on the market. A typical example is set out in U.S. Pat. No. 5,878,745. This shows a gastro-laryngeal mask in which the supraglottic tube is a pipe through which several tubes can be fed. These tubes have lumens which are used for ventilation and for an oesophageal access. 
     Inserting a larynx mask is not always easy. Larynx marks with a relatively rigid supraglottic tube can be introduced more easily, whereby their rigidity prevents adaptation of the position of the larynx mask to the anatomical conditions. Insertion into the pharyngeal cavity by means of a relatively rigid supraglottic tube can result in injury, and positioning in the pharyngeal cavity is not always reliable. 
     Highly flexible larynx masks with corresponding highly flexible supraglottic tubes allow better positioning in the larynx but are more difficult and therefore occasionally more traumatic to insert and more difficult to position in the pharynx. Accordingly, it often happens that when inserting such highly flexible larynx masks the distal end of the larynx mask, known as the tip, is bent over. This means that reliable sealing of the larynx mask is no longer present. To remedy this problem a more rigid material can be resorted to, whereby, however, the advantages of the highly flexible materials are lost. The result is traumatic effects in the central pharyngeal cavity. Even with a slightly increased air pressure in the cuff this problem cannot always reliably be solved. In the larynx masks known today, the oesophageal passage always passes through the cuff. This complicates the entire manufacturing of the larynx mask. If kinking or even just slightly greater bending of the tip of the larynx mask occurs the oesophageal passage is mostly then no longer free and an instrument or a tube can no longer be passed through. 
     A number of larynx masks with an oesophageal passage are known. The oesophageal passage ends in an oesophageal outlet on the extreme distal end of the larynx mask. The oesophageal passage now has to pass through the circumferential sealing area of the larynx mask. If a larynx mask is a version without an inflatable cuff, as set out in documents EP 1 875 937 or GB 2 404 863, this is relatively unproblematic as the larynx mask is overall designed much more rigidly and in practice kinking of the tip does not constitute a relevant problem. 
     Considerably more complex is the situation in the case of larynx masks with an inflatable cuff. On the one hand due to the thin wall of the cuff the tip of the larynx mask is very flexible and therefore susceptible to kinking, and on the other hand passing the oesophageal passage through the cuff is very problematic. This problem of passing through the cuff is solved by WO 2006/125 986 with a complex four-part larynx mask and a separate tube as the oesophageal passage which can subsequently be pushed through the cover plate and the tracheal tube. 
     A similar design in disclosed in US 2004/0020491. Additionally here the passed through separate tube of the oesophageal passage is sealed with a separate cuff. 
     Although the solution with a separate tube as the oesophageal passage reinforces the larynx mask overall, so that the risk of kinking of the tip is reduced, it makes the entire design larger and less manageable. This also applies to the solution in accordance with U.S. Pat. No. 5,878,745. 
     Finally a larynx mask is known from US 2003/0037790 with an inflatable cuff whereby where the closed oesophageal passage is passed enclosed over the cuff and the outlet lies at the proximal end of the tip on the other side of the inflatable cuff. The closed course, with multiple bends, makes use of the oesophageal passage for instrumentation practically impossible. 
     SUMMARY 
     It is therefore the aim of the present invention to improve a larynx mask in such a way that when using a highly flexible material said problems no longer occur, or their occurrence is greatly reduced, and also allow regurgitated food and liquids to pass into the dorsal pharynx. In addition improved use of the oesophageal passage for instrumentation should be made possible. 
     This aim is achieved by a larynx mask suitable for insertion through the middle of the pharynx via the epiglottis, comprising a cover plate with a tube insertion connector, a respiration lumen opening and an oesophageal passage as well as an inflatable cuff peripherally surrounding the cover plate on the ventral side, whereby the cover plate extends proximally over the cuff, wherein the oesophageal passage emerges at the proximal end of the cover plate on the dorsal side and is passed over the cuff as an open channel, whereby reinforcing means acting on both sides of this channel and in the axial direction of the channel are present which counteract possible kinking of the proximal tip of the larynx mask. 
     Other advantageous embodiments are set out in the dependent claims and their relevance and action mechanism are explained in the following description with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings show two preferred variants of the subject matter of the invention, with  FIGS. 1 to 7  showing a first embodiment and  FIGS. 8 to 10  showing a second embodiment. 
         FIG. 1  shows a perspective overall view of the larynx mask in accordance with the invention with a connected supraglottic tube with a connecting connection. 
         FIG. 2  shows a ventral distal view of the larynx mask and 
         FIG. 3  again shows a perspective view, but seen from the dorsal proximal side. 
         FIG. 4  shows a diametric longitudinal section through the larynx mask in which 
         FIG. 5  is a vertical section through the larynx mask in the area close to the tube insertion connection looking towards the distal end, and 
         FIG. 6  shows an approximately central cross-section looking towards the proximal end, while 
         FIG. 7  again shows a vertical section close to the distal end of the cover plate looking towards the distal end. 
         FIG. 8  shows a second embodiment of the larynx mask with a view towards the dorsal side, while 
         FIG. 9  shows a vertical section through the larynx mask in the area of its top. Finally 
         FIG. 10  again shows a perspective view of the second embodiment of the larynx mask. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1 , the larynx mask  1  with a connected supraglottic tube  2  can be seen, whereas at the other end a connecting connector  3  is attached. To connect the larynx mask  1  with the supraglottic tube  2 , the larynx mask has a tube insertion connector  11  at the distal end. 
     This tube insertion connector  11  is connected in one piece to the directly adjoining cover plate  12 , on which, again in one piece, an inflatable collar, known as the cuff  13  is formed and completely surrounds the cover plate  12  on its ventral periphery. The supraglottic tube  2  can contain two tubes or as here can preferably be provided with two separate lumens. One lumen is used as a respiration lumen, while the other lumen is designed as an instrument or oesophageal lumen. In between a third lumen may be present by means of which the bends of the supraglottic tube can be changed by means of appropriate tension and pressure means arranged therein. However, in  FIG. 1  the supraglottic tube is shown in a straight initial position. The adjustability or change in the bend of the supraglottic tube  2  can be affected by turning an adjusting ring  31 . Projecting from the connecting connector  3  is an oesophageal inlet connector  32  and a respiration inlet connector  33 . With regard to the features of larynx mask  1 , reference is made to the following figures. 
     In  FIG. 2  the larynx mask  1  is shown perspectively in a view from ventral-distal. Here the tube insertion connector  11  can be recognised and the inside can be partially seen so that a partial view into the oesophageal passage  18  is evident. In all the figures the larynx mask  1  is shown as it comes out of an appropriate plastic injection mould. Here, the inner edge of the cuff  13  is not yet connected to an internal circumferential adhesive wall  16 . Although an adhesive wall  16  is mentioned here, the connection of the edge of the cuff  13  to the adhesive wall  16  can not only take place through adhesion but also through welding. More particularly, ultrasonic welding could be considered here. Through the elasticity of the material the shape of the cuff  13  is practically the same as if it were already filled with air. For supplying the filling air into the cuff  13 , a ventilation connection  15  that opens directly into the cuff  13  is provided under the tube insertion connector  11 , as can most clearly be seen in the vertical section in  FIG. 4 . 
     Within the cover plate  12 , in the area close to the tube insertion connector  11  the respiration lumen is initially still completely closed in cross-section as is the lumen of the oesophageal passage  18 . Accordingly the respiration lumen is designated  17 ′. The vertical section in accordance with  FIG. 5  is shown looking towards the tip  4  and/or the distal end of the larynx mask. Accordingly, when looking into the oesophageal passage  18  the oesophageal outlet  14  can be seen. 
     Running from proximal to distal the respiration lumen  17 ′ continuously opens and thus forms the respiration lumen opening  17  and communicates with the sealed respiration chamber  19  lying underneath it which is delimited by the cuff  13 . In  FIG. 6  the vertical section is shown looking towards the proximal end, so that here free passage of respiration lumen  17 ′ to its outlet in the tube insertion connector  11  can be seen, while the respiration lumen opening  17  can also be seen.  FIG. 7  again shows a vertical section, relatively close to the distal end and/or close to the tip  4  of the larynx mask  1 , again looking towards the distal end. Again clearly visible are the adhesive wall  16  and the corresponding adhesive edge  16 ′ on the cuff  13 , which is here not yet connected to the adhesive wall  16 . 
     The oesophageal passage  18  running laterally ventrally next to the respiration lumen opening  17  helps on the one hand to reinforce the larynx mask in the axial direction in order to prevent or reduce kinking in the middle area of the mask, and on the other hand the oesophageal passage  18  on the ventral side helps to keep the epiglottis away from the respiration lumen opening  17 . 
     Preferably the larynx mask also has a proximally closed sack-like lumen between the oesophageal passage  18  and respiration lumen  17 ′ and respiration lumen opening  17  which allows the use of a longitudinal reinforcing element. 
     The distal end of the larynx mask  1  forms its tip  4 . In the area of the tip  4  which forms part of the cover plate  12 , the oesophageal passage  18  which runs closed through the cover plate  12  opens into oesophageal outlet  14 . The oesophageal passage  18  then passes over cuff  15  as a dorsally open channel  20 . The cross-section of this channel  20  is shown here as a half-cylinder. Correspondingly the cuff  13  is reduced in cross-section in the area of the tip  4  as the cover plate  12  runs deeper here in the ventral direction. The reduced cross-section area of the cuff  13  is designated  13 ′. In principle the cross-section of the cuff can be reduced to zero in this area so that the cuff is discontinuous in the area of the tip. However, the shown solution is preferred due to the better seal to the epiglottis. In principle the delimiting walls to the cuff  13  can run directly adjacent on the semi-cylindrical open channel  20 . The delimiting walls are in principle designed as reinforcing means  21  for the cover plate  12 . Irrespective of whether these walls are or are not reinforced or thickened in cross-section, they only work as a reinforcement through their direction perpendicular to the possible direction of kinking. This also applies if these walls are arranged directly adjacent to the open channel  20 . 
     Preferably, however, these reinforcing walls  21 ′ are applied as reinforcing means  21  opposite the open channel  20  with its channel base  24  laterally offset. This lateral offsetting forms a channel widening  22  in the form of intermediate bases. Although it would also be possible to reinforce these intermediate bases with appropriate material thickening this has little effect in the sense of preventing kinking of the tip  4 . 
     Through the offsetting of the reinforcing walls  21 ′, laterally in the transition area of the cover plate  12  to the cuff  13 , at the proximal end of this widened area an escape point  23  is practically formed on both sides. If in the event of regurgitation of the stomach contents these cannot be taken up by the oesophageal passage alone within a sufficient period of time, at the dorsal escape points  23  these stomach contents can also escape dorsally of the cuff into the pharynx, without the risk of the material entering the respiration area ventrally through the cuff. In addition, pharyngeal fluid can accumulate in the area of the open channel  20  which can be removed through the oesophageal passage directly or by way of suction with a tube. 
     In a further preferred embodiment the reinforcing walls  21 ′ can extend proximally along the dorsal inner side of the cuff only in the cuff tip area, so that the escape of stomach contents dorsally is even more efficient and not only the cuff tip but also the proximal cuff are protected against kinking. 
     In another preferred embodiment the oesophageal outlet  13  can be even further to proximal, so that the open channels  22 ,  24  are not only limited to passing over the cuff tip. This allows even more efficient escaping of regurgitated stomach contents to dorsal in the pharynx and easier removal by suction of collected pharyngeal secretion. This widened suction opening is designated  25  and is added as a broken line in  FIG. 1 . 
     The widened channel also has the advantage that an instrument or a probe or an optical device that is passed through the oesophageal passage can take on the required curvature early on in order to be introduced as required into the oesophagus. If an oesophageal passage is passed through the cuff, as is the case in the best known solutions in the prior art, the outlet point in the ventral direction is moved further to ventral and, accordingly, in certain circumstances the required handling ability may be made more difficult. 
     With the reduced cuff tip with an open channel, a wedge-shaping of the larynx mask in the upper oesophageal inlet is deliberately dispensed with. In addition to the above advantages this also has the benefit that the naso-oesophageal or naso-gastric access allows appropriate instrumentation or the insertion of temporary or permanent tubes. 
     As an additional possibility of reinforcing the tip  4  of the larynx mask  1  another solution is shown in  FIGS. 8 to 10 . As the oesophageal passage does not run exactly centrically in the longitudinal direction, its extension, namely the open channel  20 , also does not run centrically but slightly from lateral to towards the center. The channel widening  22  can also be seen in the solution shown here. In addition, here, on the channel widening  22 , which here is also in the form of a thickened wall section, reinforcing ribs  21 ″ running parallel to the wall  21 ′ are additionally applied on the channel widening  22  between the first reinforcing means of the reinforcing walls  21 ′. This achieves optimum reinforcement against the kinking effect. Nevertheless it is still ensured that stomach contents can escape. 
     The larynx mask in accordance with the invention therefore on the one hand provides greater security for the anaesthetist against possible kinking of the tip  4  of the larynx mask as a result of which he can work more quickly and reliably, and at the same time provides improved access to the oesophagus thanks to the oesophageal outlet  14  which is in the proximal direction earlier, thereby achieving greater mobility of the instruments, tubes or optical system being passed through the oesophageal passage. 
     LIST OF REFERENCE NUMBERS 
     
         
           1 . Larynx mask 
           2 . Supraglottic tube 
           3 . Connecting connector 
           4 . Tip of a larynx mask 
           11 . Tube insertion connector 
           12 . Cover plate 
           13 . Cuff 
           13 ′. Cuff in the area of the tip 
           14 . Oesophageal outlet 
           15 . Ventilation connection of the cuff 
           16 . Adhesive wall 
           16 ′. Adhesive edge 
           17 . Respiration lumen opening 
           17 ′. Respiration lumen 
           18 . Oesophageal passage 
           19 . Sealed respiration chamber 
           20 . Open channel 
           21 . Reinforcing means 
           21 ′. Reinforcing walls 
           21 ″ Reinforcing ribs 
           22 . Channel enlargement 
           23 . Escape points 
           24 . Base of the channel 
           25 . Widened suction opening 
           31 . Adjusting ring 
           32 . Oesophageal inlet connector 
           33 . Respiration inlet connector