Abstract:
A portable device for administering a gas. The device can supply at least one nostril of a user with at least part of a gas. The device includes at least one gas distribution nozzle and a support, with which the at least one gas distribution nozzle is supported or held in position on the face of the user. The at least one gas distribution nozzle is held along at least part of the outer wall or surface of the nose or cheeks of the user, when the device is positioned on the head or the face of the user. The at least one nozzle is outside the user&#39;s nostrils.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a device for administering a gas or a gaseous mixture, in particular oxygen, via the nasal route to a user, such as a patient, a sportsman or an airline pilot, for example. 
     As is known, in the medical field, devices for respiratory assistance generally comprise a generator of highly concentrated oxygen and nose tubes. 
     The generator can be either a cylinder containing oxygen of cryogenic and/or pharmaceutical quality, or an oxygen concentrator, such as a device with PSA (pressure swing adsorption) cycles, with which oxygen, having a purity of greater than 90%, can be produced from air. 
     On leaving the generator, the oxygen circulates through tubes having a length generally of about one to three meters, and is injected through a nozzle consisting of two small tubes of 10 to 12 mm in length, which are inserted into the nostrils so that the oxygen is inhaled by the patient. 
     In patients suffering from respiratory insufficiency, these small tubes have to be inserted into their nostrils for periods varying between 12 and 24 hours a day, depending on the severity of their condition. 
     However, the small tubes sometimes cause wounds or irritations on the inner nasal walls and these, under the added effect of the injection of highly concentrated oxygen (≧90%) and the high speed of ejection of the gas, may become very painful. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is therefore to solve the problem of effective administration of oxygen to a user, such as a patient, in particular a patient with serious respiratory insufficiency, which administration of oxygen does not damage the inner walls or nasal cavities of this user or patient, even when the latter has to be supplied with oxygen for long periods of time, which can be up to 24 hours a day. 
     The solution afforded by the present invention is therefore a portable device for administering a gas, which device can supply at least one nostril of a user with at least part of a gas, comprising at least one gas distribution nozzle and support means with which at least said gas distribution nozzle can be supported and/or held in position close to or in contact with the face of the user and along at least part of the outer wall or surface of the face situated near the nasal region of said user, when the device is positioned on the head and/or the face of said user. 
     The invention also relates to a portable device for administering a gas, which device can supply at least one nostril of a user with at least part of a gas, comprising at least one gas distribution nozzle and support means with which at least said gas distribution nozzle can be supported and/or held in position close to or in contact with the face of the user and along at least part of the outer nasal wall or surface of said user, when the device is positioned on the head and/or the face of said user. 
     Moreover, the invention also relates to a portable device for administering a gas, which device can supply at least one nostril of a user with at least part of a gas, comprising at least one gas distribution nozzle and support means with which at least said gas distribution nozzle can be supported and/or held in position close to or in contact with the face of the user and along at least part of the wall or surface of at least one of the cheeks of the user and close to the nasal region of said user, when the device is positioned on the head and/or the face of said user. 
     Depending on circumstances, the device according to the invention can comprise one or more of the following characteristics: 
     At least one gas distribution nozzle is directed toward at least one nostril of the user and is positioned outside said at least one nostril, when the device is positioned on the head and/or the face of the user. In other words, according to the invention, the gas distribution nozzle or nozzles do not engage, even partially, in the user&#39;s nostrils. To put it another way, these nozzles are positioned in immediate proximity to the nostrils, that is to say to the nasal region, either on the cheeks, or on the longitudinal sides of the nose, and the gas flow delivered via the nozzles thus travels, at least temporarily and/or locally, outside said nostrils before passing into them upon inhalation of the gas by the user. 
     It additionally comprises gas-directing means with which the gas can be directed to at least said distribution nozzle, said gas-directing means preferably comprising at least one gas channel. 
     The gas-directing means comprise at least one supple or flexible channel, preferably at least one channel made of polymer. 
     It comprises at least two gas distribution nozzles, said distribution nozzles preferably being arranged in such a way as to be positioned on either side of the nose of the user, along the outer wall of the nose. 
     The gas-directing means comprise at least one multiple gas channel formed by an outer conduit and at least one inner conduit. 
     The gas-directing means comprise at least one multiple gas channel formed by an outer channel and at least one inner channel which are concentric. 
     The support means are chosen from the group consisting of glasses or half-glasses, devices in the shape of an artificial nose, headbands, and pince-nez devices. 
     The nozzle or nozzles have a diameter or a width of between 0.2 mm and 25 mm, preferably of between 0.4 mm and 13 mm. 
     The nozzle or nozzles have a gas outlet end of cylindrical, oval or flattened shape, preferably a flattened outlet end. 
     Furthermore, the invention also relates to a method for administering a gas or a gaseous mixture to a user via the nasal route, in which: 
     (a) said gas or gaseous mixture is directed to at least one gas distribution nozzle situated close to or in contact with the face of the user and arranged along at least part of the outer wall or surface of the face situated near the nasal region of said user, in particular along at least part of the outer nasal wall or along at least part of the wall or surface of at least one of the cheeks of the user and close to the nasal region of said user; and 
     (b) at least one flow of said gas or gaseous mixture is delivered by means of said at least one distribution nozzle in the direction of at least one of the nostrils of the user, said flow of gas sweeping across at least part of the outer surface or wall of the face of the user, in particular at least part of the outer surface or wall of the nose or at least one of the cheeks of the user. 
     The gas or gaseous mixture is preferably oxygen or a gas containing oxygen. 
     The speed of the gas or gaseous mixture delivered via the distribution nozzle is advantageously between 0.1 m/s and 10 m/s, preferably lower than about 5 m/s. 
     The gaseous flow is preferably delivered via at least two distribution nozzles. 
     In addition, the invention also relates to equipment for administration of gas by inhalation, usable in particular in the medical field, comprising at least one gas source connected to at least one device according to the invention, means for regulating the gas flow rate preferably being arranged between said gas source and said device. 
     In particular, it additionally comprises gas humidification means arranged between the means for regulating the gas flow rate and the nozzle or nozzles. 
     The gas source is advantageously a gas container, preferably a gas cylinder, or an oxygen concentrator apparatus with which it is possible to produce oxygen, or a gas rich in oxygen, from air. 
     Indeed, while respecting the characteristics in terms of the flow rate and concentration of oxygen inhaled by a patient, the injection system according to the invention avoids any injury to the patient and most certainly affords a considerable improvement to the known devices and systems. 
     This is because the known administration devices traditionally comprise a system of injection nozzles with which it is possible to direct the jet of oxygen into the nostril or nostrils and, consequently, to control the flow of oxygen passing into the patient&#39;s airways. 
     The nozzles are usually tubes arranged inside the nostrils. 
     In order to avoid the abovementioned injuries inside the nasal cavity, it is possible to contemplate injecting the oxygen through nozzles placed outside the nostrils. 
     However, it is known that a jet of gas has a tendency to dissipate into the air as it travels, which fact leads to a decrease in its average speed and prevents it from reaching its target, either partially or completely. 
     Thus, a jet of oxygen injected into the air using a nozzle of any given shape can fully reach its “target”, that is to say a nostril, only if it satisfies the conditions of being very fine, of always having a high speed, and of being injected very close to the nostril. 
     This can therefore only be achieved with a very fine nozzle placed at the entry to the nostril, in accordance with the known prior art. 
     The jet of oxygen, whose speed is necessarily high in order to reach the target, can rebound off the nasal walls if the nozzle is poorly oriented, resulting in a loss of oxygen and especially in poor control of the quantity inhaled. 
     In any event, the sensation of inhaling a jet of gas injected at high speed directly into the nostrils is very unpleasant. 
     This, however, does not happen with the device according to the invention. 
     In fact, the studies carried out by the inventors show that, by virtue of the device according to the invention, it is possible to apply a jet of gas along a convex wall constituted, for example, by the outer wall of the nostril or nostrils, in such a way that it follows this wall as far as the inside of the nostril and can be inhaled by the user or, according to another example, along the outer wall or surface of the cheek situated in proximity to the nostril or nostrils. 
     To do this, the characteristics of the jet must be within a very precise range, particularly in terms of speed and dimensions. 
     Consequently, the inventors of the present invention have shown that a parietal jet of oxygen injected, for example, along the nose (and not directly inside the nostrils), can, if it is properly oriented and if its characteristics conform with the curvatures of the nose, reach the nostrils in its entirety and be inhaled by the patient or user. 
     Such a solution makes it possible, at one and the same time, to avoid introducing tubes into the nostrils and to control the flow rate of oxygen inhaled by the patient or user, thereby effectively solving the problem set out above. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will now be better understood on the basis of an illustrative embodiment and the attached figures, which are given by way of example and are nonlimiting. 
     FIG. 1 shows a gas administration device according to a first embodiment; 
     FIG. 2 is a graph showing percent of oxygen inhaled by a user as a function of the speed of injection of the oxygen; 
     FIG. 3 shows a gas administration device according to a second embodiment; 
     FIG. 4 shows a gas administration device according to a third embodiment; 
     FIG. 5 shows a gas administration device according to a fourth embodiment; 
     FIG. 6 shows oxygen therapy equipment according to the invention; 
     FIG. 7 shows a first nozzle embodiment including gas supply channels; and 
     FIG. 8 shows a second nozzle embodiment including gas supply channels. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 and 3 through  5  are sketches showing a gas administration device according to the invention, comprising two nozzles  1  for injecting oxygen to a user  2 . 
     As can be seen, the nozzles  1  are arranged along the outer wall  4  of the nose of the user  2 , and on either side thereof, that is to say on each side of the bridge of the nose, and they are held in position there by suitable support means, such as one or more straps or a headband  5 ′ (FIG.  5 ), a structure or a frame which can be positioned on the user&#39;s head, a device in the form of glasses  5 ″ (FIG. 1) or half-glasses (FIGS. 3 and 4) bearing on the ears and/or the nose of the user  2 , or similar. 
     According to another embodiment (not shown), the nozzle can also be made integral with a device of the “false nose” type, that is to say an artificial nose substituting either at least the lower part of the outer wall or surface of the nose, that is to say the region situated at the end of the nose near the nostrils, or at least the upper part of the outer wall or surface of the nose, that is to say the region situated at the root of the nose and between the eyes, so as to make it possible, in both cases, to standardize the characteristics and orientation of the nozzle or nozzles regardless of the shape of the patient&#39;s nose. 
     The false nose can incorporate the nozzles, that is to say these can be fixed to this false nose or made integral in the actual structure thereof, directly by casting for example. 
     The oxygen injected, substantially from the top downward, travels along the outer wall  4  of the nose before passing inside the nose via the nostrils  3 . 
     In order to check the effectiveness of the device according to the invention, a study was carried out to determine the conditions for achieving complete control of the quantity of oxygen inhaled. 
     To do this: 
     The face of the user was simulated using a mask reproducing a human face; 
     The nostrils of the mask were fitted with tubes connected to a pump and an oxygen analyzer, making it possible both to simulate the user&#39;s breathing and to establish the quantity of oxygen actually inhaled; 
     An injection nozzle was placed at different positions on the nose in order to determine the necessary precision of positioning and its influence on the quantity of oxygen inhaled; 
     A Maintaining a constant rate of breathing, namely a rate simulating the rate of human breathing during the inhalation phase, that is to say approximately 24 l/min. The injection rate was modified over time and different nozzle dimensions were tested in order to detemine the range of functioning (dimensions, speed) within which all the injected oxygen is inhaled; 
     Finally, a ventilator placed at varying distances from the mask made it possible to study the attachment and the control of the jet of oxygen under external atmospheric conditions (presence of wind). 
     The results obtained show that it is possible to effectively control the flow rate of inhaled oxygen when the speed of the gas is maintained at less than 10 m/s, preferably less than about 5 m/s. 
     Above this level, some of the injected oxygen is not inhaled by the patient. 
     Nevertheless, in all cases the greater part of the injected oxygen is inhaled by the patient. 
     An important observation concerns the presence or absence of wind. 
     Thus, in the absence of a ventilator simulating the wind, the position of the injection nozzle on the nose has only a very slight influence on the performance of the system. 
     By contrast, in the presence of wind (of the order of several m/s), that is to say a ventilator placed at 1.50 meters, for example, control is poor if the nozzle is placed at the top of the nose (at the level of the supports of the glasses type). However, if the nozzle is placed at the lower part of the nose, control is perfect up to about 5 m/s. 
     FIG. 2, attached, shows clearly the percentage of oxygen inhaled by the user, simulated by the pump/oxygen analyzer system, as a function of the speed of injection of the oxygen for the different configurations represented in FIGS. 3 an  4 : 
     Reference: corresponds to the percentage of oxygen obtained when the injection of oxygen is effected inside the actual inhalation tube. This reference corresponds to an inhalation of  100 % of the injected oxygen; 
     Top of nose: the injection nozzle is placed at the top part of the nose, at the position where supports of the glasses type are normally situated (FIG.  4 ); 
     Bottom of nose: the injection nozzle is placed at the bottom part of the nose, at the site of the curvature of the vertical wall of the nose (FIG.  3 ); 
     V+Top of nose: the injection nozzle is placed at the top part of the nose in the presence of a ventilator placed at about 1.50 meters; 
     V+Bottom of nose: the injection nozzle is placed at the bottom part of the nose in the presence of a ventilator placed at about 1.50 meters. 
     FIG. 2 confirms that it is possible to effectively control the flow rate of oxygen inhaled by the patient when the nozzle is placed at the bottom part of the nose, even in the presence of a strong wind. 
     The nozzle is the same for all these configurations, that is to say a nozzle of flattened shape, the height of its outlet slit being 0.4 mm and its width about 1.25 cm. The flow rate corresponding to about 5 m/s (the limit speed for complete control) is 1.5 l/min for each nozzle. The trials on other slit heights are similar and the limit speed always appears to be situated toward about 5 m/s. 
     This last observation is important since it implies that the results presented can be obtained with very different flow rates, the speed of the injected oxygen being the important parameter in this system, on condition that the injected jet remains sufficiently fine to behave as a parietal jet. 
     Thus, with a nozzle slit of 0.8 mm in height and about 1.25 cm in width, complete control of oxygen inhaled by the user was achieved up to a flow rate of about 3 l/min for each nozzle and for a limit speed of about 5 m/s. 
     FIG. 6 for its part shows oxygen therapy equipment according to the invention, comprising a gas source which can be: either a gaseous oxygen cylinder  110 , a generator of oxygen-enriched air, that is to say an oxygen concentrator  120 , or a container holding liquid oxygen  130 . 
     This gas source is connected by way of a gas channel  11  to a device according to the invention, as shown in FIGS. 1 and 3 through  5 . 
     It will be seen from FIG. 6 that pressureregulating means, such as a gas pressure reducer  12 , and means for regulating the gas flow rate, such as a flow rate selector  16 , are arranged between the oxygen source and the device according to the invention. 
     In addition, one will also note the possible presence, on line  11 , of a bacteriological filter  15  and of a gas humidifier  13  situated between the gas pressure reducer  12  and the device  50  with nozzles  1  according to the invention. 
     In addition, FIG. 7 shows a diagrammatic representation of a particular embodiment of the invention, according to which the gas distribution nozzle  1  is supplied with two gases of a different nature and/or composition which are directed along a multiple channel  20  formed, for example, by an outer conduit  21  and an inner conduit  22 , in such a way as to allow different gases to be administered to the user. 
     FIG. 8 is similar to FIG. 7, except that in this case the nozzle  1  is supplied with gas via a multiple channel  20  formed by an outer conduit  21  and several inner conduits  22  and  23  which are juxtaposed and/or concentric. 
     The invention is particularly suitable for the medical field, but it can also be used for other purposes, for example in sports or aeronautics, when a sportsman or an airline pilot may temporarily require oxygen assistance.