AU750450B2 - Respiratory mask - Google Patents

Description

WO 00/35525 PCT/AU99/01091 RESPIRATORY

MASK

This invention relates to medical apparatus. More particularly although not exclusively it discloses an improved respiratory mask to assist persons suffering from Obstructive Sleep Apnea and other respiratory conditions or needs which require a positive pressure airway supply system.

Obstructive Sleep Apnea is the collapse of the airway during sleep. This prevents air from entering the lungs and causes breathing to temporarily stop. The result is a disrupted sleep pattern, daytime fatigue and general reduction in the well being of the sufferer. It has been estimated about 4% of middle aged men and about 2% of middle aged women have Obstructive Sleep Apnea. One method of treating the condition is the application of a continuous positive pressure to the airway during sleep. This serves to hold the airway open and enables normal breathing. The apparatus required for this treatment includes a pressurised air supply and a mask, which seals over the user's nose. Existing masks however are limited in facial contact area and thus tend to be unstable. If force is applied to one side through contact with a pillow during sleep for example, the mask can be dislodged and the air seal broken. Further, existing masks typically comprise a triangular box encompassing the wearer's nose. This box has a relatively large dead air space containing a percentage of previously exhaled air. The box also protrudes well out from the face to clear the end of the nose and this severely restricts the user's vision, in particular looking down.

Existing devices also use rather cumbersome and complicated system of fastening straps, which pass through slots in the mask and are adjusted to fit the user's face. Cleaning of these masks necessitates removal of the straps and subsequent refitting and adjustment of them before re-use, Consequently many user's neglect to regularly clean their mask.

It is therefore an object of this invention to ameliorate the aforementioned disadvantages and accordingly a respiratory mask is disclosed for use in the treatment of Obstructive Sleep Apnea or other ailments and uses where positive airway pressure is required.

SUBSTITUTE SHEET (RULE 26) PCT/AU99/01091 Received 18 July 2000 -2- The disclosed respiratory mask invention overcomes the problems associated with comfort, leakage of air and noise of wearers of respiratory masks. This invention may be worn by people who suffer from Obstructive Sleep Apnea or other respiratory conditions, or by any person who requires a positive airway supply system.

The disclosed respiratory mask invention comprises of a semi ridged and semi soft silicone type material, which is moulded on a mould taken from an exact impression of the wearers face. The invention as worn, covers and is in contact with and including both cheeks, eyebrows forehead, upper lip, the entire nose including the nose bridge and tubular protrusions into each nostril. Another version of this disclosed respiratory mask is all of the above, with additional configuration which is a built-in chin strap. The said chin strap is an extension of the cheek covers, which encloses and encapsulates the entire chin area and the mouth is left accessible through a suitably shaped orifice allowing the wearer to have normal speech and normal mouth breathing.

The respiratory mask invention has tubular nostril protrusion which are exactly moulded to the shape of the wearers nostrils. The respiratory mask invention has large cheek covers which allows the wearer to sleep on their side without dislodging the mask as the mask becomes sandwiched between the pillow and the wearer's cheek. The respiratory mask invention has a cavity, which is an exact reproduction of the nose and around the same area are located slightly raised ridges, which tend to slightly depress the wearer's face to increase sealing. A unique concept of this respiratory mask invention places a gas transfer box inside the mask parameters but it is separated from the facial tissue by a wall, therefore providing greater wearer comfort as it is quieter for the wearer and their sleeping partner. The only exit ports from the gas transfer box are guided directly into the nostrils of the wearer. The respiratory mask invention is held on the face by means of a suitable skull cap with straps, and the mask and straps are connected by suitably shaped rings which enables quick connection and disconnection on or off the face of the wearer. This also facilitates easy cleaning. The respiratory mask invention has a reinforcing metal or other rigid material bar bars which is moulded over and along the ridge of the nose section. The inside of this respiratory mask, that is the side in contact with the facial tissue, has a frosted type finish and this helps with ventilation for the wearer. The respiratory mask invention may also have concave shaped dimples, which also add extra ventilation for the wearer. These dimples may include holes and this is again extra ventilation particularly for wearers who perspire more than normal. The respiratory mask has suitably placed eye orifices cut into it. These allow full vision for the arer and also the wearer is able to wear their optical glasses.

AMIEDE'L SHEET

IPEA/AU

WO 00/35525 PCT/AU99/01091 3 DESCRIPTION OF THE DRAWINGS Two currently preferred embodiments of this invention will now be described with reference to the attached representations in which Figure 1 shows a perspective view from the front of a respiratory mask according to this invention.

Figure 2 is a perspective view of the mask of figure1 from the frosted facial contact side.

Figure 3 shows the mask of figure 1 fitted to a wearer's face. (head strap or skull cap not shown) Figure 4 shows assembly of the mask including the triangular and rectangular shaped rings.

Figure 5 shows a perspective view of a second form of the mask.

Referring to figure 1 to 4 the mask is preferably moulded from a silicon type material.

It may comprise a face plate with portions 1, 2, and 3 which closely follow the contours and covers the wearer's cheeks, nose, forehead and define apertures 3A for the eyes. In order to achieve a suitably close fit the mask would be custom formed to the individual wearer's face using a suitable moulding technique. A U shaped strip 4 of metal or other rigid material may also be moulded into the nose portion 2 to further ensure a gas tight fit in this area. In accordance with this invention the gas intake box 5 is located directly under the of the wearer's nose and adjacent to the upper lip. This substantially reduces the forward protrusion of the mask as compared with conventional prior art devices in which the intake box covers and extends out forward of the nose. This novel construction also enables the dead air space enclosed by the intake box to be reduced to about 30cc. Typical prior art devices have a dead air space of about 120cc. As will be appreciated this smaller dead air space reduces the volume of stale air re-breathed by the wearer and also the amount of condensation which accumulates in the mask. The novel position of the intake box 5 according to this invention also dramatically reduces the obstruction to vision present with some prior art masks.

As mentioned earlier some prior art masks protrude out further and sit higher on the wearer's face. In accordance with another aspect of the invention as best shown in figure I the intake box 5 is isolated from the wearer's nose by a wall 6 so that any condensation or mucus forming in the box during use is collected inside pockets 7 away WO 00/35525 PCT/AU99/01091 4 from the wearer's face. Orifices 8 extend through this wall and become the tubular nostril protrusions and they are moulded to the shape of the wearer's nostrils. They allow pressurised gas supplied to the intake box through aperture 9 to be freely breathed in by the wearer. Additional sealing means are preferably also provided in the form of a series of ridges. 10 is a small ridge formed on the outside of the nostril protrusion which improves gas sealing. 11 are ridges formed inside the mask area which surrounds the nostril and nose area. These ridges 11 press against the wearer's face to further minimise gas leakage.

Preferably the mask may also include a transverse fastening bar 12 which extends through the mask under the intake box. The ends of the bars are grooved to receive a removable triangular shaped fastening ring or the like 15 which is connected to any suitable form of head strap or skull cap (not shown). A hook 13 may also be moulded into the upper forehead portion 3 of the mask to receive one rectangular shaped ring or the like 16. (mostly obscured by the head straps) With this embodiment dimples 14 may also be moulded into the mask to increase ventilation and improve wearer comfort. Holes (not shown) may also be drilled into these dimples to better aerate the mask, whilst being worn.

A second embodiment of this invention is shown in figure 5. The main components that correspond in function to those of figures 1 to 3 are marked by the same numerals but with the addition of an accent With this example a chin strap 17 is formed below the gas intake box This additional fitting is necessary with some wearers to keep the mouth closed and to maintain airway pressure during sleep.

It will thus be appreciated that this invention at least in the form of the embodiments described provide a novel and useful improvement to respiratory masks for sufferers of Obstructive Sleep Apnea and other respiratory conditions and by any person requiring positive airway supply systems. Clearly however the disclosed invention as described could have alterations, substitutions and modifications performed by a person skilled in the art, without departing from the intended scope as defined in the appended claims.

Claims (9)

1. A respiratory mask which comprises of areas of semi ridged and semi soft silicone type material, which is moulded on a mould taken from an exact impression of the wearer's face and it covers and is in contact with and including both cheeks, eyebrows, forehead, upper lip, the entire nose including the nose bridge and tubular protrusions into each nostril, with an additional configuration which is a built-in chin strap that is an extension of the cheek covers, which encloses and encapsulates the entire chin area, whilst the mouth is left accessible through a suitably shaped orifice allowing the wearer to have normal speech and normal mouth breathing.

2. The respiratory mask of claim 1 has tubular nostril protrusions that are a true internal shape of the expanded nostrils of the wearer's nose.

3. The respiratory mask of claim 1 has large cheek covers that are the shape of the wearer's cheeks and allow the wearer to sleep on either side, so the cheek covers are then pressed between the pillow and the wearer's cheeks maintaining mask positioning and stability.

4. The respiratory mask of claim 1 has a nose cavity, being the negative of the wearers nose from whom the impression was taken, and this cavity helps maintain the mask's position as it fits over and is in full contact with the nose so no air gap or space exists between them, also at least one or multiple raised ridges up to 1.0mm high and wide radiating from, and including the nostril protrusions and these said ridges depress the wearer's facial tissue for additional sealing to resist any pressurised gas leakage when being worn. The respiratory mask of claim 1 includes a gas/ air transfer box/ chamber located over the mouth region, though not enclosing the mouth and this said box is enclosed and doesn't contact any facial tissue except for the two exit ports, which are the two tubular nostril protrusions and also the said transfer box has an orifice to accept the gas/ air hose/ fitting, as well as having two moisture traps either side of the nostrils which accommodate any build up of moisture or mucus from pressurised gas/ air and exhaled gas/ air and the said transfer box doubles as a mixing chamber/ expansion chamber and may include a reinforcing rib inside the said box constructed at, and between the nostrils and the flat angular box section opposite the nostril region, and also the inside surface of the said transfer box may have a frosted type finish which aids in a further reduction of sound being transmitted to the wearer.

PCT/AU99/01091 Received 18 July 2000 -6-

6. The respiratory mask of claim 1 is held on the wearer's face, from whom the impression is taken, by three mounting fastening points and two of these fastening points are at either end of a transverse fastening bar, which extends through the mask under the intake/transfer box/ chamber and the ends of the said bar are grooved to receive a removable triangular shaped fastening ring or the like which is connected to any suitable form of head strap or skull cap not shown and these two lower straps lie over the lower section of the cheek covers and assist in the mask's mounting stability whist the third fastening point is an in built hook moulded into the upper forehead portion of the mask to receive a square shaped fastening ring or the like, which in turn retains one strap over the head and two straps around the head from any suitable form of head strap or skull cap not shown and this moulded hook is so placed in the middle of the forehead to allow two of the three head straps to just sit on the outside of the mask's forehead virtually without tension to the wearer's face and these two straps also retain the forehead section of the mask in place, and third and centre strap applies a small amount of upward tension, which in turn is applied to the tubular nostril protrusions hence maintaing additional light weight sealing on the raised ridge which is moulded around the wearer's nostril area.

7. The respiratory mask of claim 1 contains a reinforcing metal or other rigid material bar bars custom made to suit each individual mask, moulded into and inside the mask moulding and the metal or other rigid material bar bars is suitably positioned over and along the ridge of the nose section.

8. The respiratory mask of claim 1 has a frosted like finish on the side contacting the facial tissue and this finish aids in skin ventilation and wearer comfort, while the outer side of the mask is finished in a smooth finish.

9. The respiratory mask of claim 1 has suitably placed eye orifices cut into it, large enough to allow the wearer full vision. The respiratory mask of claim 1 may be fitted with concave shaped dimples i depressions and these said dimples may include holes to better aerate the mask for greater wearer's comfort. COLLIN ANDERSON 15th JULY 2000 AMIEAIEEIAU IPEAIAVa