Abstract:
Method and devices intended to be used at sensing of breathing of a man or an animal in order to with a breathing sensor securely sense the breathing regardless of whether it occurs through the nose or mouth. A device ( 1 ) conducts breathing air flows to and from the nose as well as the mouth past a position ( 5 ), at which the sensor is located. In one embodiment the device is tubular and has two orifices ( 2, 3 ) for location at the nose and mouth respectively, as well as a third orifice ( 5 ) onto which a sensor may be fastened by snap action.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is the national stage application of international application PCT/SE98/01404 filed on Jul. 20, 1998, which designated the United States of America. 
    
    
     FIELD OF THE INVENTION 
     The present invention refers to a method and assisting devices intended to be used to sense the breathing of a man or an animal. 
     With “to sense breathing” in this document is referred primarily to achieve a signal which to a substantial extent follows the breathing air flow. 
     BACKGROUND OF THE INVENTION 
     In connection to utilization of an equipment to sense breathing according to the international patent application WO 94/16620 a breathing sensor should be placed so that it is located in the breathing air flow at exhaling as well as inhaling. This is exemplified in the application by a retainer that is applied in a nostril. 
     SUMMARY OF THE INVENTION 
     A problem that is solved by the present invention, is by means of a breathing sensor to reliably sense the breathing regardless of whether it occurs through the nose or mouth. Another problem that is solved is to securely hold the breathing sensor in its position and simply be able to apply and remove the same. Moreover it should be possible to move the sensor from one patient to another without a risk of transmisson of infection. A further problem that is solved is to give small influence on normal breathing. These and other problems are solved by a method and devices according to the following patent claims. 
     In the first place thus a device is used that conducts breathing air flows to and from the nose as well as the mouth past a position at which the sensor is placed so that breathing detection may take place irrespective of how breathing occurs. 
     In a first embodiment a tubular device is used that is fixed between and with an end orifice at each of the nose and mouth and a third orifice of the sensor placed on the tubular device. This embodiment includes three main parts: the tubular device, a fastening plate for the tubular device and a sensor retainer which can be fastened to the device by snap action. A second embodiment is constituted mainly by a convexly rounded part intended to be fastened above the nose and mouth together with the first embodiment and formed such that it captures the breathing air flows and leads them to the orifice of the sensor. The tubular as well as the convexly rounded part are designed such that they do not constitute any obstruction for normal breathing. A variant of the convexly rounded part is provided to be able to be used together with a nasal canula. The sensor retainer according to the invention can also be used for patients that have been intubated, whereby a special intermediate part with a connection tube piece for the sensor retainer is used. 
     In a third embodiment, the tubular device is externally shaped with a flattened portion which is provided with adhesive means so that a special fixing plate is not required to fasten the tubular device to the upper lip. This embodiment can also be designed to be directly fastened to a nasal canula without requirement of the convexly rounded part according to the second embodiment. 
     The devices according to the invention not only may be used with an equipment of the type mentioned above that utilizes a fibre end in the breathing air flow, but also together with other breathing sensors intended to be placed in breathing air flow, for example such being based on temperature sensing. 
     Devices that utilize hoses to conduct air flows from nose and mouth respectively to a common breathing sensor are known through WO 9641571 A (FIG. 8 a , claims 1-10) and WO 9705824 Al (FIG. 5). Moreover, devices with several sensors for sensing mouth and nose breathing are known through the above references, as well as U.S. Pat. No. 5,069,222 A and U.S. Pat. No. 5,413,111 A. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described in greater detail in connection to the drawing. 
     FIGS. 1A,  1 B and  1 C shows a tubular device according to a first embodiment of the invention in which FIG. 1A shows a frontal view, FIG. 1B shows a section A—A according to FIG. 1A, and FIG. 1C shows a lateral view with a nose ring mounted. 
     FIG. 2 in three views shows a retainer of a device according to FIG. 1, where FIG. 2A shows a frontal view, FIG. 2B shows a view from below and FIG. 2C shows a lateral view. 
     FIG. 3 shows in three partial figures a second embodiment of a retainer similar to that of FIG.  2 . FIG. 3A thus shows a frontal view, FIG. 3B a view from below while FIG. 3C shows how the retainer can be made from a material strip. 
     FIG. 4 in three views and two sections shows a fibre retainer intended to be releasably fastened to the device according to FIG.  1 . FIGS. 4A,  4 D and  4 E thus shows three partial views, while FIG.  4 B and FIG. 4C show sections according to B—B and A—A in FIG. 4A respectively. 
     FIG. 5 in three partial views, FIGS. 5A,  5 B and  5 C shows a second embodiment in the form of a convexly rounded part which can be used with the devices according to FIGS. 1-4. 
     FIG. 6 in two views, from the front according to FIG.  6 A and laterally according to FIG. 6B, shows a second embodiment of the convexly rounded part according to FIG. 5, intended to be used with a nasal camula. 
     FIG. 7 shows an intermediate piece with a connection pipe intended to be used at intubation. FIG. 7A shows the intermediate piece from one side and FIG. 7B shows a section A—A according to. FIG.  7 A. 
     FIGS. 8A,  8 B and  8 C shows a third embodiment of the invention corresponding to the tubular device  1  in FIGS. 1A,  1 B and  1 C, where FIG. 8A shows a frontal view, FIG. 8B shows section A—A according to FIG. 8A, and FIG. 8C shows a lateral view with a nose ring mounted. 
     FIGS. 9A,  9 B, and  9 C shows a modified version for a nasal canula of the device according to FIGS. 8A,  8 B and  8 C with corresponding partial views. FIG. 9D shows a section B—B according to FIG.  9 A. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The embodiment of the invention according to FIGS. 1A-C consists of a tubular part  1  with a first end orifice  2  and a second end orifice  3  and a channel interconnecting the orifices. At the first end orifice  2  the tube is cut mainly perpendicularly. In proximity to the first end orifice  2  the tubular part  1  is angled about 70 degrees so that the first end orifice can be directed inwards towards air channels in the nose when it is placed in a nostril. A sealing ring  4  of slow elastic foam plastic is arranged on the tubular part  1  at the first end orifice  2  (FIG.  1 C). The other end orifice  3  of the tubular part  1  is also open a portion along the longitudinal direction of the tubular portion and it is this opening that is intended to be placed over the mouth when the device is used. 
     A tube piece  5  which is connected to the inner channel of the tubular part  1  is located on the tubular part so that there is formed almost a straight line for an airflow from the first end orifice  2  to the tube connector  5 , which thus exhibits a third end orifice. This dimensioning has proven to give good breathing detection at nasal as well as oral breathing. The pipe connector  5  at its end is provided with a groove  6  in order to faciliate fastening of a sensor part by snap action. 
     A retainer in the shape of a plate  7  with a tube part  10  (FIG. 2) is intended to keep the tubular part  1  in place by threading this through the tube part  10  and the plate  7  is adhered to the upper lip. The plate  7  is also provided with holes  8 , 9  so that the device if necessary can be fixed by means of a rubber string or the like round the head. In addition the plate  7  is provided with an adhering layer  11 . 
     In an alternative embodiment of the retainer according to FIGS. 3 ( 3 A,  3 B,  3 C) this consists of a strip  12  according to FIG.  3 C. The strip  12  is provided with a cross shaped groove  13  and two opposite grooves  14  so that one of the ends of the strip  12  may be threaded through the cross shaped groove  13  until the opposite grooves  14  come into engagement with the groove  13  and tube part  10  and the plate  7  is formed by the strip  12 . 
     As indicated in FIGS. 2 and 3 the retainers may be provided with recesses  15  on the tubular part  10 , whereby the recesses  15  are adapted to receive the tube connector  5  thereon. As an alternative to the retainers according to FIGS. 2 and 3 the tubular part  1  may be provided with a fastening plate. 
     The fibre retainer according to FIG. 4 is intended to protect the end of an optical fibre which constitutes the breathing sensor, and faciliate its location on the assisting devices according to invention. The fibre retainer  30  is. shown in three projections in FIGS. 4A,  4 D and  4 E and in two sectional views according to B—B in FIG.  4 B and A—A in FIG. 4C respectively. It consists of a longish part  31  which at one end has a substantially cylindric air duct  32  passing through. A channel  34  runs through the longish part  31  and mainly perpendicularly versus the air duct  32  adapted for an optical fibre (not shown), which in a mounted state is retained in the fibre retainer so that the fibre end is located centrally in the air duct  32 . The fibre channel  34  is provided with an expanded portion  35  with a diameter corresponding to the protection cover of the fibre. One end of the air duct  32  is funnel-shaped widened and provided with a groove  36  so that a flange  37  is formed. The flange  37  is adapted to be received in the groove  6  so that the fibre retainer can be snapped onto the connecting tube  5 . The longish portion of the fibre retainer  31  is flattened and is provided with opposite grip surfaces  37  and  38  as well as a protrusion  39  in order to faciliate its fastening and removal. In those cases where the invention is used together with sensors other than optical fibers only the fibre retainer needs to be modified and adapted to the sensor type in question. 
     The device according to FIGS. 5A,  5 B and  5 C is constituted by a convexly rounded part  45  of a thin material of substantially uniform thickness, intended to be placed above parts of nose and mouth of a patient and is used together with devices according to FIGS. 1-4. The convexly rounded part  45  is provided with holes  46 ,  47  so that it can be fastened around the head by means of a rubber string or the like. It has a dome-shaped, somewhat unsymmetrical form with a convex portion  49  seen in section from outside and a somewhat concave portion  48 . It is shaped such that its position can be tested out for the individual patient with either the convex or the concave portion directed upwards against the nose, in order to achieve the best possible respiratory detection by means of the device according to FIG. 1 by nasal breathing as well as oral breathing. The reason why a convexly rounded portion  45  sometimes is required is that certain patients especially by oral breathing have a weak and uneven breathing air flow. 
     The device according to FIGS. 6A and 6B constitutes an alternative to the embodiment according to FIGS. 5 A-C. In the first place it is intended to be used with a nasal canula  50  which is used to supply oxygen to both nostrils. It mainly consists of a convexly rounded device  51  provided with two holes  52  so that it can be threaded over the nasal canula and held in place under the nose by this. Thus the convexly rounded device  51  can serve as a retainer for a tubular device  1  according to FIG. 1 or placed above a separately retained tubular device  1 . The convexly rounded device  51  then captures the breathing flow at nasal breathing and leads it to the the upper orifice  2  while the lower orifice  3  normally is held in place in front of the mouth and captures the breathing air flow by oral breathing. 
     The intermediate piece  70  according to FIGS. 7A and 7B is provided with a through channel  71  which can be coupled to a tracheal tube and is provided with a connection tube  72  with a cross channel  73  similar to the tube connecting piece  5 . By intubated patients the intermediate piece  70  can be used with the fibre retainer  30  instead of the tubular device  1 , whereby a reliable detection of the breathing may be carried out. 
     In the embodiment according to FIGS. 8A,  8 B and  8 C the tubular device  1  shown in FIGS. 1A,  1 B and  1 C is replaced by an adapter device  81  which has an essentially similar inner channel between the first end orifice  2  and the second end orifice  3  as the tubular device  1 , but externally has a longish flattened portion along the second end orifice  3  and the main portion of the inner channel. The longish flattened portion, which constitutes the main portion of the adapter device  81 , is designed with a waist of grip surfaces in order to faciliate application, and above the other, longish end orifice  3  is provided with a dome-shaped portion, on which a cushion  82  of resilient material e.g. foam plastic has been applied, outwards provided with an adhesion means  83  with a covering protection film  84 . Through this design the adapter device  81  can be fastened directly on the upper lip after tearing off the protection film  84  and no further retainer is required. 
     In the adapter device  81  the connection tube  5  is arranged in a straight line with the air flow from the first end orifice  2 , while the channel from the second end orifice  3  forms an angle of about 70 degrees with the connection tube  5 . The sealing ring  4  in this case is constituted by ring-shaped flanges of resilient material. The cross-sectional areas of the air channels from the end orifices  2  and  3  and in the connection tube  5  are adapted to give detectable breathing air flow through the connection tube  5  regardless if nasal or oral breathing occurs when the first end orifice  2  is located in or at a nostril and the second end orifice  3  outside the mouth of a measuring object. 
     FIGS. 9A,  9 B,  9 C and  9 D shows how the device according to FIGS. 8A,  8 B and  8 C may be modified to be used in connection with a nasal canula  50 . The main portion of the adapter device  91  has thus been formed with a tongue  92  which can be threaded over and hung on the nasal canula and replace one of its orifices, which has been removed. Oxygen via the nasal canula is then supplied via one of the nostrils while breathing measurement may be performed by the adapter device  91  in the other nostril. In order to allow an air flow large enough at oral breathing from the second end orifice  3  to reach the connection tube  5 , the intermediate air channel  93  at the tongue  92  has been given an oblong cross section, see FIG.  9 D. As in the adapter device  81  in this case the tongue  92  has been provided with a pad  82  with adhesion means  83  and a protection film  84 . 
     Other designs are also possible within the scope of the following patent claims.