CN1735439A - Masks and their components - Google Patents

Abstract

A comfortable low leak mask assembly for a non-invasive positive pressure gas supply (NIPPV) is provided that may improve patient compliance and/or therapeutic action. The mask system includes: headgear having a strap that is substantially non-stretchable and/or that can be fine-tuned; and/or a mask and/or cushion that includes various components to improve/customize sealing and/or fit at selected locations on the patient's face.

Description

Masks and their components

technical field

The present invention generally relates to whole face masks for use in non-invasive positive air pressure devices (NIPPA), continuous positive airway pressure devices (CPAP) and air delivery devices.

Background technique

Delivery of positive pressure breathable gas from a gas supply to a patient requires some kind of interface between the machine and the patient. A tube placed in the trachea is often used as the patient interface for invasive gas delivery. For non-invasive air delivery, some form of mask is used as the patient interface.

Masks typically include a chamber with a nose-receiving cavity formed by an outer shell or frame. The mask also typically includes a portion for comfortable contact with the face, such as a cushion, which is secured to the outer shell or the edge of the frame. The mask is usually held in place on the patient's face by headgear, such as a set of elastic straps. Improving the comfort of a mask, especially when the mask is worn for several hours, continues to challenge mask designers.

Unless the mask is customized for each user, most of the devices of the mask are a compromise design because the face shapes are very different. One mask design may work well with the nose shape of a small subset of patient populations (eg, high nasal bridge), but not well fit another segment of the population with differently shaped noses (eg, low nasal bridge). Designing a mask to seal well over the bridge of the nose is particularly difficult since this area of the face is particularly sensitive.

Creases in the mask cushion may cause discomfort to the patient's face during long-term wear. Also despite the use of the cushion, the edges of the mask frame can still be felt through the cushion, creating an uncomfortable surface against the patient's face, especially when the cushion is compressed.

In some cases, masks suitably include ventilation apertures which, among other things, allow a controlled leak out of the mask in order to prevent _CO2 buildup within the mask. Inadvertent or unintentional mask leaks also exist, for example, at the junction between the mask and the patient's skin. The use of masks that create low or zero unintentional leaks can improve the operation of advanced control algorithms in air delivery devices, particularly those that respond to respiratory flow signals.

During sleep, the patient may move. In addition, the shape of the patient's head may change during sleep due to, for example, swelling. Although the mask fits the patient well at the beginning of fitting, the mask subsequently does not fit well because of this movement during the night. Prior art masks typically include elastic headgear straps that can be shortened or lengthened, or reconfigured over the head, to return the mask to a comfortable, low-leakage position.

The maintenance pressure provided by the air supply device can be varied during treatment. Some continuous positive airway pressure (CPAP) devices create an initial ramp from low pressure to therapeutic pressure. Other CPAP devices can automatically adjust the pressure as dictated by the airflow range. Other devices can vary the maintenance pressure during the patient's breathing cycle, for example providing a higher maintenance pressure during inhalation and a lower maintenance pressure during exhalation. Elastic headgear straps must be configured to accommodate this maintenance pressure. If the elastic is configured for high pressures, there is a danger that the elastic will become too tight for comfort at low pressures.

Contents of the invention

It is an aspect of the present invention to provide a comfortable low leakage mask for use in non-invasive air delivery devices which overcomes the limitations of prior art masks.

In another aspect, it is desirable to provide a mask system having one or more of the following features, each of which contributes to improved patient compliance and/or treatment: headgear comprising substantially non-retractable and/or Or straps that can be finely adjusted; and/or masks and/or cushions that include various features to enhance/improve the seal, and/or conform to selected locations on the patient's face.

In the following description, the following anatomical terms are used:

Cranial: In the direction of the vector from the feet to the head and beyond. The nose is on the cephalic side of the lips and chin.

Caudal: In the direction of the vector from head to feet and beyond these parts.

Front: In the direction of the vector from the rear of the body to the front of the body and beyond. The nose is in front of the ears and the mask is in front of the nose.

Rear: In the direction of the vector pointing from the front of the body to the rear of the body. The ears are at the back of the nose.

The crown plane, a plane parallel to the plane containing the vertices of the head, feet, and shoulders. The band that goes around the top of the head from the left ear to the right ear is called the coronal band.

Front-to-back plane: A plane parallel to the plane passing through the head, feet, posterior spine, and tip of the nose.

Nautical: Associated with (the muscles of) the back of the neck.

Occipital: Pertaining to the bony prominence where the muscles of the back of the neck enter the back of the base of the skull.

External auditory canal: ear hole.

kgf: kilogram force.

Zygomatic process: the roughly half-almond-sized protrusion of the zygomatic bone (strictly speaking, it is the main body of the zygomatic process).

Inner corner of the eye: The point where the upper and lower eyelids meet near the bridge of the nose.

These and other aspects of the preferred embodiments are described in detail below, or may be apparent from the description.

Description of drawings

The illustrated embodiments are described in detail below with reference to the accompanying drawings, in which like numbers represent like parts, these drawings are:

1-5 illustrate a first embodiment of the present invention;

5A and 5B illustrate another embodiment of the present invention;

Figures 5C-5H illustrate another embodiment of the present invention with fine-tuning and quick-release capabilities;

Figures 6-15A illustrate the mechanism and principle of changing the tension of the belt according to the air pressure delivered to the patient;

16-35 illustrate another embodiment of the present invention;

Figures 36-40B illustrate an embodiment of the invention in which the sides of a patient's nose can be effectively sealed;

Figures 41-53 illustrate another embodiment of the present invention showing a frame/cushion that enhances the seal along the sides of the patient's nose;

Figures 53A-53G illustrate another embodiment of a frame in which fins are formed to support the cushion;

Figure 53H shows an additional embodiment of the invention in which the frame includes a gasket;

Figure 53I shows an exploded perspective view of another embodiment of the present invention;

Figures 53J-53P illustrate yet another embodiment of the invention in which a frame supports an inflatable cushion;

54A-54C are rear, side and bottom plan views, respectively, showing a prior art ACLAIM cushion in exploded view;

Figure 54D is a cross-sectional view of the prior art ACLAIM cushion shown in Figures 54A-54C;

55A-55C are a rear view, a bottom plan view and a side view, respectively, showing a cushion assembly of a first embodiment of the present invention;

Figure 55D is a cross-sectional view of the cushion assembly of the first embodiment of the present invention;

56-56F are rear view, top plan view, bottom plan view, side view, rear perspective view and front perspective view, respectively, of the flexible member of the cushion assembly of the first embodiment of the present invention;

57-57C are graphs showing the mechanical properties of the first embodiment of the present invention, the MIRAGE® cushion and the ACLAIM cushion, respectively;

58 is a cross-sectional view of a cushion assembly of a second embodiment of the present invention;

59A-59E are respectively a front view, a rear view, a side view, a front perspective view and a rear perspective view of the flexible part of the cushion assembly according to the second embodiment of the present invention;

60A-60D are graphs showing the mechanical properties of the first and second embodiment of the cushion assembly, the MIRAGE® cushion, and the ACLAIM cushion respectively, and comparing the mechanical properties of the three cushions;

Fig. 61 is a graph showing the operation of the cushion assembly under pressure according to the first and second embodiments of the present invention;

62 is a perspective view of a cushion assembly according to a third embodiment of the present invention;

63A-63E are respectively the front view, rear view, side view, front perspective view and rear perspective view of the flexible part of the cushion assembly according to the third embodiment of the present invention;

64A-64E are respectively the front view, rear view, side view, front perspective view and rear perspective view of the cushion assembly holder of the third embodiment of the present invention;

65 is a cross-sectional view of a cushion assembly according to a fourth embodiment of the present invention;

66 is a cross-sectional view of a cushion assembly according to a fifth embodiment of the present invention;

67 is a cross-sectional view of a cushion assembly according to a sixth embodiment of the present invention;

Figures 68 and 69 illustrate an embodiment of the invention in which the stiffness of the cushion can be selectively varied;

Figures 70-79 illustrate other embodiments of the cushion of the present invention;

Figure 80 shows a cross-sectional view of yet another embodiment of the present invention;

Figure 81 is a relaxation curve for a foam suitable for use as a flexible member in all embodiments of the present invention.

Detailed ways

The following detailed description of the invention includes disclosure of many different components suitable for use in various embodiments of mask assemblies. It should be understood that any component described for one embodiment may be used with one or more components of another embodiment.

Headgear

A. Non-retractable belt

1-5 illustrate one embodiment of a mask system including a mask assembly 15 and a headgear assembly 20 . As shown in FIG. 1 , headgear assembly 20 includes a plurality of straps constructed and arranged to substantially surround a patient's head. These straps are attached to the mask assembly 15 so that the mask assembly 15 can be secured relative to the patient's face. As an example only, mask assembly 15 is shown to illustrate the use of headgear assembly 20 . The mask assembly 15 may be replaced with any suitable respiratory mask, as would be apparent to one of ordinary skill.

To secure the mask assembly 15 in place, the headgear assembly 20 utilizes front and rear straps 25 and horizontal straps 30 . The horizontal belt 30 is arranged substantially horizontally and wraps around the patient's head. Each end 31 of each horizontal strap 30 is connected to the mask assembly 15 . In the following detailed description, the arrangement between the horizontal belt 30 and the mask assembly 15 is explained. The horizontal band 30 preferably passes right under each ear and through the neck muscles into the padded area at the base of the skull, generally indicated at 36 in FIG. 2 .

The rear end 40 of the anterior-posterior strap 25 is generally located at the terminus of the horizontal strap 30, thereby being positioned in the mid-posterior region of the patient's head. As shown in FIG. 1 , the width of the anterior-posterior strip 25 in the posterior region of the patient's head is relatively wide, for example about twice the width of the remainder of the anterior-posterior nuchal section 25 . This increased surface level is advantageous because it helps prevent the band from pinching into the fatty or soft back of the patient's head when pressure changes or band tension changes. Of course, the strap 25 should not be so wide and/or so thick that it becomes uncomfortable. The strap is preferably made of a cool material such as BREATHOPRENE ^(TM) .

Anterior-posterior strap 25 extends from horizontal strap 30, e.g., from rear end 40f, over the apex of the skull, generally indicated at 45, and generally medially across the forehead of the patient's head, generally indicated at 50 (see FIG. 2) . The front-to-back strap 25 has a front end 55 that is attached to the mask assembly 15, as described in detail below.

The headgear assembly 20 preferably includes a pair of crown straps 35 connecting the front and rear straps and the horizontal straps 25 and 30 . The upper end 60 of each coronal band 35 is connected to the anterior-posterior band 25 near the apex 45 of the patient's head, from which each coronal band 35 protrudes, for example, from the upper end 60, laterally and inferiorly across the head, and from each The lower end 65 of the coronal band 35 is connected to the horizontal band 30 directly in front of and directly below the ears.

Each lower end 65 of the coronal strap 35 is attached to the horizontal strap 30 by sewing and/or adhesives. Alternatively, the horizontal strap 30 may be connected to both the coronal strap 35 and/or the anterior-posterior strap 25 with one or more buckle members that are adjustable between one or more strap portions. Alternatively, one or more straps of headgear assembly 20 may be formed from a single piece of material.

To maintain the safety and comfort of the mask assembly 15, the straps of the headgear assembly 20 are preferably formed to be substantially non-retractable. In other words, with some flexibility, however the straps preferably do not stretch significantly. These bands are sufficiently flexible or rigid that they retain their shape. Contemplated materials for the strap include polyvinyl chloride (PVC), leather, polypropylene, or polyurethane. Of course, other materials may also be used. For example, other materials deemed suitable may be strong cloth straps. These straps may also be considered lined with felt material for increased patient comfort. Other variations include perforations or eyelets to allow heat dissipation through the straps.

B. Belt fine-tuning

1. The first embodiment

Referring to FIG. 1 , headgear assembly 20 is preferably attached to mask assembly 15 in such a manner that the position of mask assembly 15 relative to the straps of headgear assembly 20 can be adjusted. The mask assembly 15 includes a frame assembly 70 , a patient-interfacing or patient-contacting cushion 75 , and a cushion support 80 interposed between the frame assembly 70 and the cushion 75 . Cushion support 80 includes holes (not shown) through which pressurized air may be delivered to the pressurization chamber of mask assembly 70, the pressurized air being delivered to the patient's airway. Typically the elbow 85 is loosely connected to the bore of the cushion support 80 . The swivel elbow includes a quick release connection 86 that connects to an air delivery tube (not shown), which in turn connects to air delivery means such as an air supply (not shown).

The frame assembly 70 includes a chassis 95 (best shown in FIG. 3 ) having one or more transverse members 100 . The transverse member 100 supports a cantilever extension 90 which in turn is connected to the front end 55 of the front and rear straps 25 . The front end 55 of the front and rear straps 25 has a threaded part 105 which passes through a receiving hole 91 formed by the extension part 90, as best seen in FIGS. 1 and 2 . The nut 110 can be turned on the threaded portion 105 so that the distance between the extension member 90 and the patient's forehead 50 can be adjusted. Thus, the tension of the straps can be fine-tuned, especially when the front-to-rear straps 25 are made of substantially non-stretchable material, as described above.

FIG. 3 shows a front view of mask assembly 10 . As can be seen in FIG. 3 , chassis 95 includes a plurality of fingers 115 extending from chassis 95 . The lowermost finger members 115 on each side of the chassis 95 include apertures 120 configured to receive threaded members 105 protruding from each end of the horizontal strap 30 . Nut 110 may be threaded to threaded portion 105 so that the distance between mask assembly 15 and the patient's face may be fine-tuned. Thus, the strips can be tensioned with a high degree of accuracy so that for a given pressure range of about 2 to 40 cm of water column height, just the right amount of force is applied to the face.

As clearly shown in Figures 3 and 4, the threaded portion 105 is substantially rectangular in cross-section, comprising two relatively flat sides and two sides with threaded portions. The shape of the holes 91 and 120 is complementary to the shape of the threaded portion 105 . For example, the holes 91 and 102 have a generally rectangular shape, whereby when the nut 110 is adjusted, the threaded portion can be prevented from rotating. Although not shown, the end of the threaded portion 105 also includes a feature with an oblong hole to help prevent the threaded portion 105 from turning.

FIG. 4 is a side view showing more clearly the connection between the various horizontal straps 30 and the frame assembly 70 . Additionally, FIG. 4 shows that each finger portion 115 is movably, eg rotatably, connected to the lateral portions 96 and 97 of the chassis 95 . In this particular example, the top two fingers 115 are connected to a crossbar 125 , while the bottom two fingers 115 are connected to a similar crossbar 130 . The two top fingers and the two bottom fingers on each side of the chassis can thus move in unison, which is advantageous from the point of view of force distribution. It should be considered, however, that each finger is movable independently relative to the transverse members 96 and 97 of the chassis 95 .

In this embodiment, the threaded portion 105 protruding from the end 31 of each horizontal band 30 passes through receiving holes 120 formed in the lower two finger portions 115 . In this way, any slack in the horizontal strap 30 will be taken up when the nut 110 is tightened. When all the slack has been taken up, further tightening of the nut 110 will cause the right hand lower two fingers 115 to rotate clockwise relative to the cushion support 80 (viewed from above). The lower two sections on the left hand side, will turn counterclockwise when viewed from above. Cushion support 80 is deformable at least at side portion 82 proximate finger portion 115 . Due to this deformation, the side portion 82 can apply a force to a corresponding portion in the cushion 75, compressing the sides of the patient's nose.

As shown in FIG. 4, the cushion 75 and the flexible or deformable cushion support 80 may be integrated, for example, with fingers 115, to better match various facial contours. There is a compromise between making the cushion support very soft for a better fit to the face and very soft causing the mask internal volume to change excessively with each inhalation (e.g. greater than 20 ml) which makes measuring Trendy volumes are difficult. Conventional silicone rubber of about 1-3 mm thickness is suitable.

5 is a rear view showing the mask assembly 15 in which the upper two finger portions 115 on the left side of the patient's face can be pushed against one side portion 82 of the cushion support 80 by hand. The force of the upper two finger-shaped parts 115 acting on the cushion side part 82 can deform the cushion 75 so that it can push against the side of the nose, thereby accepting noses of different shapes and enhancing the sealing performance of the cushion 75 .

In Figures 1-5, the tension of the straps and the deformability of the sides 82 of the support 80 together allow the fingers to rotate and simultaneously push, thereby compressing the sides of the nose and a portion of the patient's face. Therefore, it is possible to adapt to irregularly shaped faces with independent rotation. This also helps distribute force evenly across the face, thereby loosening areas of high contact force.

Figure 5 shows the result of increasing the tension of the top strip (not shown), which increase in tension results in compression of the patient's nasal bridge area. This is particularly useful for dual pressure treatments, so that at low pressures only low forces are applied and at high pressures high forces are applied, which helps to improve comfort and sealing. Fabricating the headgear from a non-elastic material helps prevent "pistoning" of the mask on the face, ie, lifting off the face at high pressure and/or entering the face at low pressure during dual pressure therapy.

In the embodiment shown in FIGS. 1-5 , two upper fingers formed on respective lateral portions 96 and 97 of chassis 95 are shown attached to either strap member of headgear assembly 20 . However, the positioning of such upper belt portions may be as shown by imaginary lines 135 and 140 in FIG. 2 . Specifically, the imaginary line 135 represents a state where the upper band is partially connected to the middle of the coronal band 35 . Imaginary line 140 represents the state where the upper strap portion is connected to the horizontal straps 30 on each side of the headgear.

2. The second embodiment

Figures 5A and 5B illustrate another embodiment of the present invention, in which the horizontal strap 30 includes a first connecting portion C1 which is selectively connectable to a second connecting portion C2. This second connection portion C2 is fixed to the lower strap LS and the upper strap US. The upper and lower straps LS, US can be tensioned to the extent that they press against the lateral portion 82 of the frame 70, whereby an inward force can be exerted on the cushion 75 to laterally seal the sides of the patient's nose. The upper and lower straps LS and US are adjustably secured to the frame 70 (as indicated by the arrows) so that the area where the inward force acts can be better positioned. In this embodiment, the side portions 82 of the support 80 are made of a deformable material, while the apex is more rigid.

3. The third embodiment

Figures 5C-5H illustrate yet another embodiment of the present invention in which an adjustment mechanism allows for coarse and fine adjustment of the headgear tension. FIG. 5C shows the entire mask assembly including a mask frame 800 with an elbow 805 including an anti-asphyxia valve 810 . A quick release fastener 815 is configured so that the patient can easily remove the headgear as described in U.S. Patent Application No. 10/235,846, filed September 6, 2002, which is incorporated herein by reference in its entirety middle. Figure 5D shows the quick release mechanism in a partially open position, while Figure 5E shows the quick release mechanism fully open.

Strap 820 includes a pair of strap ends 820A and 820B for retaining the mask assembly on the patient's head. One of the strap ends such as 820B can be connected to one end of the mask frame in a fixed position by, for example, slot 821, thereby avoiding changes in the length of the strap 820, which can occur during repeated removal and replacement of the mask assembly. Variation in length. The other strap end 820A is configured and constructed to be adjustable. Of course, both ends of strap 820 are adjustable. Strap 820 is bent so that strap end 820B passes through slot 821 to form a loop that may be secured with rivets 822 or other fasteners.

Adjustment assembly 825 may be configured to adjust strap 820 . Specifically, as shown in FIG. 5F, the adjustment assembly includes a generally rectangular prism 830 having a strap receiving slot 835 extending through its entire length. The slot has an opening 840 shown on the end face of the prism. The prism has an upper portion 836, a lower portion 837 and a screw 845, as best shown in Figure 5G. The upper and lower portions 836 and 837 can adopt a first position suitable for coarse adjustment of the strap length, in which the strap end 820A can be pulled through the length of the slot 835 . In the second position, suitable for fine adjustment, the upper and lower sections 836 , 837 will join together such that the screw 845 contacts the strap end 820A, thereby preventing the strap from passing through the slot 835 . The screw 845, when turned, will move the strap end 820A, thereby tensioning or loosening the headgear. The upper and lower parts 836 , 837 are translatable through the slots and pin members 841 , 842 to move the screw 845 into and out of contact with the slot 835 . The screw 845 has an end extending the length of the prism 835 with a first gear portion 850 . As shown in Figure 5H, the first gear portion 850 in turn engages the second gear portion 855 at a right angle. The second gear portion 855 has a cylindrical button 860 secured thereto. Turning the cylindrical knob 860 turns the second gear portion 855 , thereby driving the first gear portion 850 , thereby driving the screw 845 . Depending on the direction of rotation, the strap is either pulled out or pushed into the slot, whereby the length of the strap can be fine-tuned.

C. Inflatable bladder - air bag and occipital pneumatic cushion

1. The first embodiment

Referring to FIG. 1 , there is shown a headgear 20 which includes a specially shaped inflatable bladder which will be referred to as an "air bag" 145 disposed along, for example, the front and back of the headgear 20 towards the belt 25 . The air bag 145 is configured to apply a relatively constant strap force to the patient's face over the entire range of mask pressures. The gas bag 145 is an active component that uses gas to do work, thereby pulling the mask to the face at relatively high pressure. The gas bag 145 communicates with the pressure in the mask through a small-diameter silicone tube 150, which is connected to the mask assembly 15 or near the gas inlet and outlet of the assembly. In this example, the tube 850 is disposed on the elbow 845, and the belt tension on the front and rear belt 25 is at least partially established by the air source pressure through the air bag 145. This tension can make the belt more tense/faster at higher pressures. More displacement, and less tension in the belt and/or less displacement at lower pressures.

While an air bag 145 is shown as the preferred embodiment, other mechanisms may be used to obtain belt tension/displacement changes, including electrical and mechanical systems. As the mask pressure increases, the increased air bag pressure inflates the air bag to a more spherical shape, thereby shortening it front and rear, thereby putting rearward traction on the cantilever arms 90, thereby making the mask more securely pressed against the face.

As a first approximation, the rearwardly directed force produced by the bag or arm 90 is proportional to mask pressure. When the nut 110 is tightened, its proportionality constant is larger, so that the air bag can be more easily elongated under a certain mask pressure. Thus, the air bag 145 can be seen as a kind of self-compensating mechanism, if the mechanism is adjusted so that at one pressure the mask seals, the mask will seal at all pressures and will always equalize the air pressure in the mask.

When the pressure increases by ΔP, the gas bag will expand by ΔV, thereby doing work ΔVΔP, thereby resisting the action of the force, and pulling the connection point 91 on the cantilever 90 backward for a certain distance.

Although air pockets 145 are formed only on the top belt, additional air pockets may be formed on the remaining belts, including the horizontal belt 30 . In this embodiment, however, no air pockets 145 are added to the lower belt, since the natural course of the patient's jaw and lower lip forms an undulating shape, which somewhat approximates the effect of the pockets 145, thereby providing Within the operating pressure range, good movement develops in this area. In other words, the sealing mechanism at the top of the mask is different from the overall rear sealing mechanism at the bottom of the mask. For the bottom of the mask, mask designers can rely on the patient's lower lip and jaw for compression, while at the top of the mask, a different mechanism is used because the facial structure in the nose bridge area is bony and stiff.

2. Details of air bag

Having described the air bag 145 in a general sense, the description below with reference to FIGS. 6-15A further details the more specific principles of the air bag.

The gas bag 145 is a rectangular parallelepiped thin-walled tube made of rubber such as silicone rubber, which can be crimped along the two sides and then closed at the non-corrugated ends. The non-creased closed end is inserted into the headgear of the mask assembly 15, such as the front-to-back strap 25. Figures 6 and 7 show the air bag 145 in a relaxed state, where there is substantially no pressure or no pressure at all, such as during a patient exhalation, while Figures 8 and 9 show the air bag 145 at therapeutic pressure, such as during a patient inhalation . For dual air pressure devices, the patient is exposed to a relatively high pressure during inhalation and a lower pressure during exhalation, inflating the air bag 145 to pressure p will cause the air bag 145 to shorten or widen, Thus the head strap 25 will be pulled tighter.

It is assumed below that the bag 145 is slack in the longitudinal direction and rigid in the transverse direction so that it can maintain the above-mentioned flat-topped transverse portion under all pressures. This can be done by, for example, laterally bonding rigid rods to the top and bottom surfaces, or molding the top and bottom surfaces with transverse ridges, and/or using internal tie wires between the left and right retractable walls , to get this flat top horizontal section. In fact, the basic concepts and the following descriptions are loosened roughly without such elaboration.

In the example of FIG. 10, the air bag 145 has a width W and an inflated height 2h. The retractable sides are assumed to exert negligible force and are not included in the calculations. The force on the belt is f. In FIG. 10 , the gas bag 145 is cut in half transversely, and a pair of rigid plates, one of which is indicated at 155 , are secured at this cut. The two plates are connected by a rigid rod 160 . The force on the rigid rod 160 is also f.

Assume that the axial surface tension (force/unit length) on the top strip is t. Since the assembly does not change over time, the total force of the forces acting on the visible plate 155 must be zero. These forces include a force 2tW acting on the left, a force 2pWh acting on the right and a force f acting on the rigid rod 160 on the right:

2tW＝f+2pWh (1)

If for p > 0, there is no surface tension on the strip, then the top and bottom surfaces of the gas pocket 145 will together form a cylinder (θ = π/2). When the belt 25 is under tension, the surface will become an incompletely symmetrical sector of two cylinders of radius r, as shown in the cross-section of FIG. 11 .

The line where the two surfaces intersect the belt is in equilibrium, ie there is no net force acting on it. Since the surface of the air pocket 145 beyond the connection point is irrelevant, the whole beyond the connection point can be replaced by a remaining cylinder of radius r.

[0093] The cross-section of the top or bottom surface is an arc of a circle having a radius r and an angle 2Θ subtending the center.

According to simple geometry, the angle between the top or bottom surface of the gas bag 145 and the extension line of the strip is also θ, as shown in FIG. 12 . Since the net force at the connection is zero, we get:

f＝2Wt cos(θ)

As can be clearly seen from Fig. 12, another constraint equation is:

h＝r(1-cos(θ))

Finally, if the air bag 145 has a leveled length L (distance between strips), the circumference of the arc is:

L＝2rθ

So there are four simultaneous equations, five unknowns p, h, t, f and θ, and two constants W and L. The solution of f is:

f＝pWLcos(θ)/θ (0<θ<π/2) (5)

[0097] Note the following characteristics:

(i) If the air bag is flattened, that is, θ→0, any positive pressure will produce infinite force;

(ii) If θ = π/2, ie the air pocket is cylindrical, then f is zero for all p. Neglecting the properties of the telescoping sides, W and L play the same role in force generation. Doubling either will double the force.

[0098] The force generated varies with the length of the air bag 145. It can be seen from Figure 11 that the distance x between the two ends of the air bag is determined by the following equation:

x＝2rsin(θ)

Substituting r in equation (4) gives:

x＝Lsin(θ)/θ

Notice again:

f=pWLcos(θ)/θ

List Table 1 using the above equation. The second row of Table 1 shows the air bag length "x" as a percentage of the fixed length L for various angles Θ (see Figure 11). The third row shows the resulting force "f" (see Figure 10) expressed as a percentage of the product of pressure p, width W and fixed length L.

Table 1 θ (degrees) x/L=sin(θ)/θ f/pWL=cos(θ)/θ 0 1.00 Unlimited 10 0.995 5.64 20 0.980 2.69 30 0.955 1.65 40 0.921 1.10 50 0.878 0.737 60 0.827 0.478 70 0.769 0.280 80 0.705 0.124 90 0.637 0.000

Figure 13 plots the force f (expressed as a percentage of pLW) as a function of the length x (expressed as a percentage of a fixed length L).

Differential equations (5) and (7) for angle θ get:

df/d＝-pWL[sin(θ)/θ+cos(θ)/θ ² ] (5a)

dx/dθ＝L[cos(θ)/θ-sin(θ)/ ^θ2 ] (7a)

Dividing (5a) by (7a) (for 0 < θ = π/2) gives:

df/dx＝pW[cos(θ)/θ+sin(θ)]/[sin(θ)/θ-cos(θ)] (8a)

In the limit of θ→0 (empty air pocket), the denominator becomes 1 and the numerator becomes infinite, so the spring has infinite positive stiffness. For a fully air-filled bag (θ=π/4), the stiffness is positive 4pw/π). Table 2 adds the stiffness from the previous table.

Table 2 θ (degrees) Distance between bands (maximum percentage) Generated force (coefficient of pWL) Stiffness (coefficient of Pw) 0 1.00 Unlimited Unlimited 10 0.995 5.64 592 20 0.980 2.69 78 30 0.955 1.65 25 40 0.921 1.10 11 50 0.878 0.737 6.2 60 0.827 0.478 3.9 70 0.769 0.280 2.8 80 0.705 0.124 2.1 90 0.637 0.000 1.57

example

The actual air bag has:

W=5cm=0.05m;

L=6cm=0.06m;

p=20cmH ₂ O=1960N/m ² to 2000N/m ² .

If the air bag 145 is partially inflated and held between two rigid supports, the tension in the belt increases linearly with pressure.

For any given geometry, the resulting force is proportional to the fixed length and extension of the air pocket.

For any given pressure, when the bag is at its rest length, the force developed is infinite and then drops off very quickly.

As an example, a 6cm long × 5cm wide gas bag connected to a pressure of 20cmH ₂ O generates a force of about 0.633kgf when it is shortened by 0.5cm, and a force of about 0.300kgf when it is shortened by 1.0cm. When it is shortened by 1.5cm, Generates a force of about 138g.

A consequence of this strong dependence of force on length is that tightening the headband with screws will allow any required force to be produced for a given pressure.

The mask assembly 15 is held by two straps 25 and 30 at three points on the face. The mask assembly 15 is configured as an isosceles triangle with a base of 12 cm and a height of 12 cm, and the two smaller triangles formed in the bottom corners with a height of 2 cm and a base of 2 cm are removed. Thus, the total area of the mask is 70 cm ² .

At a pressure of _20cmH2O , the air pressure will exert a force of 140Og, while at a pressure of _5cmH2O , a force of only 35Og will be exerted. It can be assumed that a force 30% higher than this, or 1820g, needs to be applied in order to seal.

Referring to Figure 15, assume that 1) the centroid C is located 4.5 cm above the bottom of the mask, or 7.5 cm below the top; 2) the bottom strap is attached approximately 3.5 cm above the bottom of the mask, or 1 cm below the centroid 3) The top band is connected to a long rod about 15cm above the centroid.

Since the connection of the bottom strap is about 15 times closer to the centroid than the connection of the top strap, the bottom strap bears 15/16 of the load, leaving only 100 g of force to be supported by the top strap.

There is a 6cm long x 5cm wide air bag on the top strap. The gas bag is connected to the mask with a tube 105 . When its length is reduced to 4.35 cm, the gas bag will generate a force of 100 g under 20 cm _H2O pressure. Under this length and pressure, the stiffness of the air bag is 0.232kg force/cm.

Assume that the air pack 145 is in series with an extensible headgear strap having a spring rate of E _STRAP . The free ends of the extensible bag and air bag are fixed. The rebound rate of the total system will be the rebound rate of the headgear plus the rebound rate of the air bag.

For example, assume a 5 cm wide by 6 cm long air bag is installed in series with a washable conventional ResMed(R) headband with a spring rate of 10 cm/kgf. The gas bag was 4.35 cm long at 20 cm _H2O pressure and applied a force of 0.1 kg, as previously described.

Under this condition, the spring constant of the air bag is 0.232kgf/cm, so its rebound rate is 4.3cm/kg. The total system therefore has a (local) spring rate of 14.3 cm/kg. The rebound rate of the entire system is controlled by the traditional belt.

As another example, starting from a 5 cm wide by 6 cm long gas bag, the pressure is 20 cm _H2O . Therefore, the length is still x ₀ =4.35 cm and the resulting force f ₀ =100 g. The bag is still in series with a strap with a spring rate of 0.1 kg/cm, ie a strap with spring constant _Kstrap = 10 kg/cm, the next step is to determine what happens when the pressure drops to 5 _cmH2O .

The equation for the force produced by the extensible band versus the length x of the air bag is:

fstrap＝f ₀ -Kstrap(xx ₀ )

Plotting this relationship on a graph of the forces produced by the air pocket at pressures of 20 _cmH2O and 5 _cmH2O , we obtain Figure 15A.

The headgear will contract such that the air bag stretches from 4.35cm to about 4.8cm, and instead of reducing the tension of the strap from 0.1kg to 0.05kg as required, it is reduced to only about 0.55kg.

The undesired strap tension supported by the bridge of the nose was 75g without the air bag. A properly adjusted air bag can usually reduce this force to zero with essentially inflexible or rigid headgear. But for very deep headbands, the unwanted strap tension is 45g, or a little more than half that without the air bag.

2. The second embodiment

16-35 illustrate another embodiment of the present invention.

A mask and headgear assembly, generally indicated at 410, is shown in Figures 16-18, shown as worn on a model head. The mask and headgear assembly 410 includes a mask assembly 412 , headgear 414 and an inflatable bladder in the form of an occipital pneumatic cushion 416 attached to the headgear 414 to allow adjustment of the headgear 414 joints.

The mask assembly 412 includes a mask body assembly 418 and a mask frame 436 (described in more detail below) which acts as a support or "skeleton" for the mask body assembly. The mask body assembly 418 is generally triangular in shape when viewed from the front, as shown in FIG. 27 .

In one preferred form, the mask body assembly includes a face-contacting portion 420 and a body portion 422 . The face-contacting portion 420 of the mask body assembly 418 is designed to provide a fine fit without causing pain, discomfort, or trauma to the skin. In particular, the face-contacting portion 420 is designed to seal around the bony portion of the nose. To avoid skin damage, it is best if no part of the face-contacting portion 420 exerts an average pressure on the face greater than the average facial capillary blood pressure (typically about 20 mmHg pressure).

In general, the face-contacting portion 420 is generally shaped to press against the sides of the nasal bone (on top of the nasal cartilage) at the level of the inner corner of the eye. Contacting face portion 420 forms an inwardly facing seal on either side of the bridge of the nose. However, the face-contacting portion 420 is designed not to press tightly against the wings of the nose, either by applying pressure directly to the cartilage, or indirectly to nearby soft components. Additionally, the contacting facial portion 420 preferably does not contact the eyes, eyelashes, or the tear duct mechanism in the inner corner of the eye.

The face-contacting part 420 of the mask body assembly 418 includes several major profiled parts, which can be seen in FIGS. 27-31. A notch 424 is formed to receive the bridge of the nose (nose root). Protrusion 426 is formed to match the frontal protrusion of the upper frontal bone. A second notch 428 is formed to receive the cheek (ie, the upper frontal process of the cheekbone). In addition, a second protrusion 430 is formed to closely fit the lower cheek and a third notch 431 is formed to receive the arch of the mandible.

In a preferred form the contact face portion 420 is made of polyurethane foam covered with a silicone "skin" or sheet. It is best if the silicone rubber material is the softest (least hard) material that can be made and has no sticky or peeling properties. Typically the outer layer of silicone rubber is bonded to the foam with an adhesive to prevent wrinkling of the outer layer relative to the foam.

Body portion 422 of mask body assembly 418 supports elbow 430, anti-asphyxia valve and vent tube. This body portion allows for relatively arbitrary deformation or bending of the mask body assembly 418 relative to the frame 436 of the mask assembly 412 and also serves as a positioning and restraining mechanism to prevent the frame from slipping out. The mask body assembly 418 is shown in the plan view of FIG. 33A and the cross-sectional view of FIG. 33B. In a preferred form, the body portion 422 is made of silicone rubber and molded with the contact mask portion 420, and adjoins the mask contact portion 422 .

The mask assembly 412 includes a compression plate or frame 436 that applies the force of the headgear to the cushion. As best shown in FIG. 21 , the frame is generally triangular in shape and includes a bottom portion 438 , side portions 440 and a top portion 442 . The frame 436 is elastically flexible so that the frame 436 can wrap around the upper and lower forehead and nose of the patient. The bottom portion 438 and top portion 422 of the frame 436 are generally fabricated to be softer than the relatively stiff side portions 440 . The top and bottom portions 442 and 438 define a longitudinal axis L about which the frame 436 is resiliently bendable, as shown in FIGS. 32 and 35 . This resilient flexing of the frame 436 allows the mask assembly 412 to more accurately fit a wide variety of facial shapes. For example, the same face assembly 412 can be used on a patient with an elongated face (so-called crocodile face) as well as a patient with a flat, wide face (so-called panda face).

The bottom portion 438 of the frame 436 is generally "C"-shaped or crescent-shaped, and the top portion 442 is generally flying-spear or chevron-shaped.

The soft top portion 442 and bottom portion 438 can be fabricated from a 1 mm thick polypropylene sheet approximately 2 cm wide. Each side portion 440 may be fabricated from a pair of aluminum sheets of the same shape, 100 mm x 20 mm x 1 mm. The frame 436 may be riveted together with four rivets, or may be held together by other known methods such as gluing.

In FIG. 32 , frame 436 shown alone includes fork brackets 444 attached to each side portion 440 . Each bracket 444 is fabricated from aluminum or other substantially rigid material. Along the length of the side portion 440 are a number of holes 446 adapted to receive bolts, thereby securing the bracket 444 . The angle of the bracket 444 relative to the side portion 440 can be adjusted by loosening the bolts, adjusting the angle and tightening the bolts. The position of the bracket 444 can be adjusted along the side portions by securing bolts in different holes. The two brackets 444 are not necessarily mounted at the same relative position along the side portion 440 . In this way, any asymmetry in the patient's face can be slightly corrected for. A bracket 444 is secured to each side portion. The bracket 444 is adapted to receive and engage the nut 448 of the threaded rod 450 of the mask 414 .

Additionally, frame 436 includes wedge-shaped pads. In use, the cushion is operatively secured between the side portions 440 and/or top portion 442 of the mask body assembly 418 and the face contacting portion 420 . The pad is about 1-2 cm thick at the top, tapering off to zero about halfway through the mask. In addition, the thickness of the wedge gradually decreases to zero from the outside to the inside. The wedge is generally made of an incompressible material. The wedge applies additional force to the top of the mask body assembly 418, thereby facilitating the seal. Additionally, the wedge compresses the mask body assembly 418 on both sides of the nasal bone, applying greater pressure on the outer edge of the mask body assembly 418 than the inner edge.

The headgear 414 includes a strap assembly 452 , an occipital pneumatic cushion 416 or other sensitive adjustable tensioning components, and a pair of threaded rods 450 connected to the mask assembly 412 . In general, mask 414 is constructed and arranged such that a force vector from mask assembly 412 to headgear 414 originating at the aerodynamic center of mask assembly 412 should pass through the midpoint between the left and right inner ear canals.

As best shown in FIGS. 22 and 32 , the strap assembly 452 includes a lower occipital strap 456 , a coronal strap 458 and a pair and pairs of ears 460 . In this embodiment, the straps 456, 458, 460 are the ends of an integral headgear assembly. However, in other embodiments of the invention, these straps may be a single strap selectively joined together in place. The straps 456, 458, 460 may be made of soft, generally non-stretchable plastic such as 1mm polypropylene sheets optionally covered on one or both sides with a layer of foam, felt or other upholstery material to increase the Comfort, since these are formed of a soft, non-stretchable material, the straps 56, 58, 60 can conform to the shape of the patient's head, but the straps typically do not elongate more than 1-2mm when subjected to a 2kgf tension.

The lower occipital band 456 passes under the occiput but over the neck muscles and is about 4 cm wide. The crown strap 458 goes over the crown of the patient's head. Ear piece 460 is configured to partially or completely surround the ear. The ear pieces 460 may be formed from an oval-shaped material with a width of about 2 cm and lined with felt that can contact the skin. The felt should extend slightly beyond the oval ring to prevent snagging in the base of the ear.

Extending from tabs 460 are a pair of rigid screws 450 . In one embodiment, the screw is made of a 5 mm threaded nylon rod. The rods 450 are configured so that they are operatively proximate to the external auditory canal and protrude forward in an approximately horizontal plane. A cylindrical nut or hand wheel 468 is provided which is threaded along each rod 450 and movable along the length of each rod. Each nut or handwheel 468 is adapted to releasably engage a bracket 444 attached to the mask frame 436 as shown in FIGS. 16 , 17 , 19 and 20 . The rod 450 is connected to the ear piece 460 of the headgear 414 using a swivel connection 470 as shown in FIGS. 19 , 23 and 24 . (The first and second positions of the rotational connection 470 are shown in Figures 24 and 25, respectively). In this way, the relative angular position of the rod 450 can be adjusted. The tension on the frame 436 and headgear 414 can be precisely adjusted by moving the nut 468 along the threaded rod. This arrangement also forms a quick release. Because frame 436 includes soft bottom portion 438 and top portion 442, as they are adjusted for a better fit for the patient, the frame will flex in accordance with the position of nut 468 on rod 450.

Inflatable occipital air cushion 416 is in force-transmitting relationship with straps 456, 458, 460 and is operatively positioned beneath strap assembly 452 and behind the head, generally in the occipital region. This occipital air cushion can be inflated and deflated. In one embodiment, as shown in FIG. 23 , the occipital air cushion 416 is connected to the air supply tube 462 of the mask assembly 412 through a tube 414 . In this way, the air pressure in the occipital cushion 416 is the same as the air pressure in the mask assembly 412 . As the pressure of the mask assembly 412 increases, the occipital air cushion 416 inflates, which causes a simultaneous increase in headgear tension and prevents the mask assembly 412 from coming off the face, causing air leakage. This dampens movement of the mask assembly 412 during different mask pressures.

The occipital air cushion 416 is designed to have a sufficiently large area (A _bladder ) so that when combined with the air pressure (P _bladder ) in the occipital air cushion 416, the air cushion will counteract head action on the harness straps 456, 458, 460 (ie, the forces acting on the bags 456, 458, 460 caused by the pressure in the mask assembly 412). In general, the area of the occipital air cushion 416 should be made sufficiently large to provide a force that exceeds the force induced by the mask, which is the product of the mask design area (A _mask ) and the mask pressure (P _mask ). therefore:

A _bladder × P _bladder = ∑ force applied to the belt

in addition,

A _bladder ×P _bladder ＞A _mask ×P _mask

In one preferred form, the occipital air cushion 416 is approximately 11 cm x 16 cm, with a wall thickness between approximately 1.5 mm and 2.5 mm, for a total deflated thickness of 3 to 5 mm.

In the embodiments described above, the pressure in the occipital air cushion 416 increases as the mask pressure increases. However, in other embodiments of the invention, parameters other than mask pressure may be used to control the inflation and deflation of the occipital air cushion 416 . For example, a sensor may detect an air leak in the mask assembly 412 by, for example, continuously monitoring the flow in an air source connected to the mask assembly 412 and the low-pass filter to find the amount of airflow leaks. When the air leak is determined to be large, the occipital pneumatic cushion 416 will be inflated. Conversely, when the air leak is determined to be relatively low, the occipital cushion can be deflated. Controlling the pressure of the occipital pneumatic cushion 416 with an air leak detection sensor can keep the wearer 414 at a minimum tension. This tension can also keep the mask 412 sealed against the face and help to reduce the discomfort of the user. , damaged skin, and other problems inherent in overtensioned headgear.

Additionally, it may be desirable to employ more than one occipital air cushion 416 on the headgear 414, and if more than one occipital air cushion 416 is employed, the occipital air cushion 416 may be placed in several locations around the headgear 414. Additionally, each of the plurality of occipital air mattresses 416 may be inflated and deflated independently of each other. In this way, asymmetries in the patient's face can be more easily compensated, since tension can be applied locally and only where necessary in the headgear 414 . The plurality of pillow dynamic air cushions 416 may thus be inflated or deflated as the pressure in the mask assembly increases or decreases respectively, or the pneumatic cushions may be inflated and deflated by sensing and control systems that are Working based on measured air leakage.

In another embodiment of the present invention, shape memory alloy (SMI) wire such as MIUSCLE WIRES® (Mondo-Tronics, Inc, San Rafael, CA, USA) can be used as a more sensitive tension member, which alloy wire is time shrinkage. (Typically, the contraction response to running a battery is due to the heating of the wire as a result of passing current through it.) If this type of component is used to achieve sensitive tension adjustment, a separate controller would need to be configured to allow the wire to be connected to the mask. Contraction synchronized with pressure increase.

Other suitable sensitive tensioning components include servo motors and "artificial muscles" formed from biomimetic materials.

D. Algorithm

The occipital air cushion 416 according to the embodiment shown in FIG. 16 is, for example, initially inflated to a predetermined tension. In one embodiment, a method of sealingly securing a mask to a patient's face comprises: disposing an occipital air cushion against the back of the head and/or neck; passing one or more straps over or through the occipital air cushion, or forming As part of the air cushion, these strips extend forward and are connected to the mask; the occipital air cushion is inflated with a pressure P _bladder which is an affine function of the mask pressure P _misk

P _bladder ＝P ₀ +A _mask P _mask

Where P ₀ is the positive pressure, large enough to make the mask seal at the lowest predetermined use pressure, A _mask is the posterior contact area between the occipital air cushion and the belt and the forward contact area between the occipital air cushion and the front back of the head smaller area.

In these embodiments, the method of using the pressure-inflated occipital air cushion as an affine function of the mask pressure comprises: measuring the mask pressure with a pressure transducer to generate a signal proportional to the mask pressure; applying the signal to an amplifier with adjustable gain and offset; Add the output of the amplifier to a voltage-controllable pressure source; use the gas in the pressure source to inflate the occipital air cushion; adjust the deviation so that the mask can achieve sealing at the minimum required pressure; adjust the gain so that the mask can achieve sealing at the highest required pressure.

In these embodiments, if the signal V _pt from the pressure sensor is V _pt =K _pt P _mask , the controllable pressure source generates pressure P _c =K _c V _c , the projected area of the contact area between the mask and the face in the backward direction is A _mask , the projected area of the belt and the occipital pneumatic cushion in the forward direction is A _bladder , and the force required to achieve sealing at zero pressure is F ₀ , then the amplifier outputs the following output voltage:

V _out ＝F ₀ /A _bladder +A _mask /A _bladder K _c /K _pt V _in

In some embodiments, inflating the occipital air cushion with pressure as an affine function of mask pressure includes: connecting the mask through a first hose to a first cylinder including a first piston, which in turn is connected to a second cylinder through a connecting rod. The second piston in the two cylinders, the second cylinder is connected to the occipital air cushion through the second flexible pipe; the above-mentioned connecting rod is biased to inflate the occipital air cushion enough to make the mask seal at the minimum predetermined use pressure.

In some embodiments, springs and/or weights are used to create the biasing force.

The means for sealing the mask to the patient's face includes: a first set of stretchable straps leading from the back of the head to the mask, the straps being tensioned so that the mask seals at the lowest intended use pressure. On the face; a second set of non-retractable straps, which still extend forward from the back of the head to the mask and rest on top of the first set of straps; Between the second set of belts, the above-mentioned occipital air cushion is in pneumatic communication with the air in the mask.

In operation, a first set of stretchable straps provides a fixed constant force independent of mask pressure, while a pneumatic cushion acting through a second set of straps provides a force that varies linearly with mask pressure. These two forces add together to form a force that is an affine function of the mask pressure. When the forward projected area of the smaller one of the contact area of the occipital air cushion with the back of the head and the contact area of the occipital air cushion with the second set of belts is the same as the rear projected area of the mask contacting the face area, it is close to the optimal configuration .

In another embodiment, the means for sealingly maintaining the mask on the patient's face comprises: a set of rigid straps extending forwardly from the back of the head to the mask; an elastic occipital cushion having a non-zero internal separation distance between the front and rear walls at internal atmospheric pressure; a hose connecting the occipital cushion to the mask.

The occipital air cushion can be conveniently made of an elastic material such as silicone rubber, latex or polyurethane, the air cushion can be filled with a resilient material, or one or more internal or external springs can be used to adjust the elasticity of the air cushion. The material is, for example, silicone rubber foam, latex foam, polyurethane foam and/or PVC foam. A comfortable innerspring can be formed with a second resilient inner occipital air cushion, which is smaller than the outer occipital air cushion, filled and sealed with air and/or fluid.

Under the internal atmospheric pressure, the distance between the front and rear walls of the occipital air cushion is preferably about 2-4 cm, preferably 3 cm, so as to allow the neck to move within an appropriate range without excessively increasing or reducing the belt force, and in the As mask pressure increases, considerable pressure is allowed on components at the back of the head (hair, skin, fat, muscles) and on the mask cushion and facial tissues.

The total stiffness of the occiput pneumatic pad wall and any foam filling or spring is preferably such that it develops a force that is about 1.5 cm below the untensioned length when the belt is tensioned to about medium , sufficient for the mask to achieve a seal at all predetermined pressures. Typically this force is around 200-600g, depending on the characteristics and fit of the mask.

As the tension in the straps increases at higher mask pressures, the mask cushion and the tissues at the back of the head will be compressed. This will cause the occipital cushion to expand, since the occipital cushion is preferably purposely constructed to be rigid and has been compressed by a tension band below its relaxed length in order to achieve the force F ₀ required to seal at any low pressure, So as the occipital cushion expands, the elasticity of the occipital cushion will provide less and less force. This loss of primary spring recoil should be compensated with an occipital pneumatic cushion having an area A _bladder which is greater than the area A _mask of the mask _.

When pressure is applied to the occipital pneumatic cushion, and forwardly on the back of the head and backwardly on the strap, a portion of the pad's flat, lateral portion will contact the strap, while the curved portions on either side of the strap will not. The belt. Only the area in contact with the belt, specifically the forward projected area of that area, will produce useful belt tension. In fact, for a face mask of a typical size for an adult, for example, an air bladder with a left and right dimension of about 17 cm, a top and bottom dimension of about 11.5 cm and a thickness of 3 cm is suitable. The left and right dimensions of the projected area in contact with the belt are about 15cm, and the upper and lower dimensions are about 10cm, so the effect of the air bladder is similar to that of a ^piston with an area of 150cm. Of course these are merely examples that vary according to preference and/or application.

frame

A. Adjustable frame

1. The first embodiment

FIG. 36 shows an embodiment of the invention comprising a frame 170 having a patient interface in the form of a cushion 172 . The frame 170 is supported on the patient's head by a plurality of straps 180 made of substantially non-stretchable material, as described above. Each strap 180 includes a threaded portion at its end adapted to receive a nut 185 so that the patient can adjust the tension of the strap. Curved strips 175 of substantially rigid material are disposed on frame 170 .

An adjustment mechanism 176 is configured to increase the adjustability of the frame 170 . Specifically, adjustment mechanism 176 includes an adjustment screw 190 that is rotatable to translate wedge 195 . The wedge is movable along an imaginary axis 196 aligned with the uppermost headband 180 disposed on the apex of the frame 170 . Turning the adjustment screw 190 translates the wedge 195 against the inner surface of the flex band 175 . In another configuration shown in FIG. 36A , the wedge 195 is configured to engage the outer surface of the curved strap 175 . In both cases, if the wedge 195 moves upward toward the top of the frame 170, the top surface 197 of the wedge 195 will hit either the inner or outer surface of the curved strap 175, which will cause the frame to rotate substantially An axis parallel to or coincident with the imaginary axis 196 is curved.

This bending will cause the side portions of the frame 170 to push against the sides of the cushion 172, thereby applying a compressive force to the sides of the patient's nose. Adjustability is created on the lower portion of the frame 170 so that the mask can be easily fitted to different types of nose features. This adjustability can of course also be provided along the top or middle of the frame. This adjustability may allow the patient to adjust the desired contact force under certain pressure. The frame can deform, rotate or bend to accommodate changes in pressure so that the force on the face is substantially constant.

2. The second embodiment

Figure 37 shows an embodiment similar to that shown in Figure 36, but including additional features. For example, FIG. 37 shows a bore 200 surrounded by an annular member such as an iron ring 210 . As shown in FIG. 38 , the aperture is adapted to receive a connector 215 , similar to an elbow, comprising a first ferrule 220 adapted to magnetically attach to ferrule 210 of frame 170 . The connecting member 215 includes a second iron ring 225 suitable for magnetically connecting the rotating member 230 via a magnetic ring 235 formed on the rotating member 230 .

Figure 38 shows more details of the cushion structure. Specifically, the cushion 172 includes a bottom member 240 such as foam and a film 245 such as silicone rubber, the former being disposed inside the frame 170 and the latter being supported by the bottom portion 240 .

In Fig. 37, the distance between the top surface 197 of the wedge 195 and the inner surface of the curved strip 175 is exaggerated so that the various components can be easily seen.

FIG. 39 shows details of adjustment screw 190 , wedge 195 and frame 170 . Specifically, the adjustment screw 190 includes a threaded portion 250 and a disc-shaped portion 255 formed on opposite ends of the adjustment knob 260 of the adjustment screw 190 . The frame 170 includes a transverse slot 260 adapted to receive the disk portion 255 . The frame 170 has a longitudinal slot 265 adapted to receive the threaded portion 250 of the adjustment screw 190 . The frame includes an additional front slot 270 for receiving a lower body portion 275 of wedge 195 . The frame 170 includes an extension 271 having an upstanding member 272 spaced from a bottom edge 273 of the frame 170 . The upright member 272 includes a threaded support portion 274 . Wedge 195 includes a slot 280 that engages an inner side wall member 285 forming longitudinal slot 265 . The wedge 195 includes a partially threaded portion 290 . The partially threaded portion 290 is adapted to engage with the threaded portion 250 .

To assemble the adjustment mechanism, the threaded portion 250 and the disc member 255 are inserted into the longitudinal slot 265 and the transverse slot 260, respectively. The partially threaded portion 290 of the wedge 195 is then lowered onto the top of the threaded portion 250 so that the body portion 275 is first positioned between the upright member 272 and the inner end of the inner wall member 285 near the bottom end 273 of the frame 170 . The slot 280 is then guided so that it slides along the wall member 285 . The wedge 195 will thus move back and forth in the groove 295 of the frame 170 as the knob 260 is turned. The two extreme positions of wedge 195 are shown in Figures 40A and 40B, respectively.

Figures 41-53 illustrate other embodiments that may apply pressure along lateral sides of the patient's face/nose. Since it is equivalent to the embodiment shown in Figs. 36-40B, like parts are given like numbers. Each of these embodiments allows for more adjustment control and easier adaptation to changes in the appearance of patients with different nose shapes.

3. The third embodiment

In the embodiment shown in Figure 4, the knob 190 is operatively connected to a rack, preferably a pair of racks 191, which are movable in opposite directions when the knob 190 is turned. The distal end 193 of the rack 191 engages a side portion of the frame, for example, the frame includes a camming surface that increases in thickness as the distal end 193 moves laterally outward, thereby allowing the frame to bend, deform, and deform about an imaginary vertical axis. and/or rotate, thereby increasing pressure on both sides of the patient's face/nose.

4. The fourth embodiment

In the embodiment shown in Figures 42A and 42B, the membrane helps seal small air leaks, so exact adjustment is not critical. Additionally, the embodiment shown in Figures 42A and 42B substantially eliminates lift from the lower jaw. Figures 42A and 42B also include additional points of adjustment whereby the fit of the mask to the patient can be further fine tuned. For example, each knob 190 is operatively connected to a portion 197 disposed on the cushion 172 .

5. Fifth Embodiment

In FIGS. 43A and 43B, the frame 170 is semi-rigid and the cushion 172 is mounted on the flexible member 300. The elastic action of member 300 to the cushion will help seal the sides of the patient's nose as tension in the strap is increased. For example, frame 170 is a fairly stiff spring compared to the stiffness of flexible member 300 . Thus, a patient with a crocodile face can rely on the rigidity of the flexible member 300, while a patient with a panda face can rely on the flexible member 300 lying flat against the frame 170, which is flexible but stiffer than the flexible member 300 rigidity. This embodiment is not shown to include an adjustment knob, but this embodiment can be used as such.

6. The sixth embodiment

In the embodiment shown in Figures 44A-44C, turning the adjustment knob 190 causes the screw camming surface 194 to engage a protrusion 196 on the cushion support, thereby compressing the cushion inwardly against the patient's nose.

7. The seventh embodiment

Figures 45, 46A and 46B illustrate yet another embodiment of the present invention, the frame includes wing portions 305 which are rotatable relative to the frame 170 . In principle this embodiment is similar to the embodiment shown in FIG. 1 in which the fingers 115 are arranged to rotate relative to the chassis 95 . Figure 46A is an exploded view of the embodiment shown in Figure 45, and Figure 46B is an assembled view of the embodiment shown in Figure 45. This embodiment, like the others, allows the sides of the cushion to more easily fit a variety of patients with different nose shapes. This embodiment can also automatically conform to facial contours because the straps 180 are attached to each side wing portion 305 of the frame 170 . Lifting of the mask/cushion from the cheeks can be reduced and a more even cushion pressure can be achieved on the face. This embodiment, like many of the other embodiments described above, can also replace the upholstery, or use removable upholstery.

8. Eighth embodiment

Figures 45A and 45B show yet another embodiment, similar to that shown in Figure 45, in which the wing portions 305 can be hinged in a number of predetermined positions by means of a snap action or escapement. FIG. 45B is a partially exploded view including tongue 306 disposed between two hinged portions on wing portion 305 . The frame 170 includes a plurality of slots 307 adapted to receive the tongue 306, thereby being adjustable to a plurality of discrete positions.

Figures 47 and 48 illustrate the position of the flap portion 305 gradually sealing against the patient's nose N as the tension of the strap is increased.

9. Ninth Embodiment

49 and 50 illustrate another embodiment of an adjustment mechanism that allows the wing portions to move, for example rotate, relative to the chassis or central frame of the mask assembly. The adjustment mechanism includes a plurality of holes 312 which can receive pins arranged on flanges 313 of the wing portions 305 . The hinge part 311 can be a hinge, a pin or a combined pin, etc.

10. Tenth embodiment

Figure 51 is an exploded perspective view showing a mask assembly 510 in accordance with another embodiment of the present invention. The mask assembly 510 has two main parts, a semi-rigid mask chassis 512 and a cushion/subframe 514, the two parts 512 and 514 are separate but can be loosened or fixed as described above. In general, mask chassis 512 is constructed and arranged to attach to mask headgear (not shown in FIG. 51 ), while cushion/subframe 514 is configured to provide a comfortable seal with the patient's face. The mask chassis 512 and cushion/subframe 514 have mating components such that the cushion/subframe can move relative to the mask chassis 512, or deform, to provide a small amount of adjustment in fitting the mask assembly 510 to the user's face.

In the following description, certain directional terms such as "top", "bottom", "left" and "right" will be used. Unless otherwise indicated, the use of these directional terms is relative to the coordinate system of the respective drawing.

Cushion/subframe 514 includes cushion portion 516 and subframe portion 518 . The two parts 516 and 518 are fixedly connected. The cushion/sub-frame 514 is sized to function as an oral mask, nasal mask, oral-nose mask, or any other type of mask that is or is compatible with the patient's treatment protocol.

The subframe portion 518 is triangular or prismatic and has an interior volume large enough to receive the upper facial organs over which the cushion/subframe plus 514 is designed to form a seal (e.g., nose, nose-mouth, etc.) . The auxiliary frame portion 518 is open on both sides. On the outside of the auxiliary frame 518, a connector 520 is arranged, which is connected to a pipe of an air source. On the inside, the subframe portion 518 is flared and opens into a flange 522 to which the upholstered portion 516 is attached. Subframe portion 518 is fabricated from a flexible or semi-flexible material such as polypropylene.

Cushion portion 516 is generally a soft conforming member which may be, for example, a silicone rubber film, a foam material (polyurethane foam) encapsulated in a plastic film, or a deformable sealed bag filled with air or other gas. The cushion portion may be molded (ie, melted) onto the sub-frame portion 18, secured with an adhesive, or secured with suitable attachment means.

Subframe portion 518 also includes components constructed and arranged to couple cushion/subframe 514 to mask chassis 512 . At the top and bottom of the subframe section, on the subframe section surface outside the patient, are attachment members 524 adapted to be inserted into corresponding receiving holes 526 on the mask chassis 512 to secure the cushion/subframe 514 to the mask Component 512. Connecting member 524 is constructed and arranged to deflect inwardly when inserted into receiving aperture 526 , thereby forming a snap-fit securement between cushion/subframe 514 and mask chassis 512 . Although connecting member 524 is shown in FIG. 51 , the connection between cushion/subframe 514 and mask chassis 512 may be any other type of suitable connection. The subframe portion 518 also includes a projection 528 having several surfaces that cooperates with an adjustment wheel 530 in a manner described below.

The mask chassis 512 is generally a triangular panel of semi-rigid material that can be molded with the cushion/subframe 514 . The mask chassis 512 provides connection receptacles 532 for respective ends of mask elements 534 . On the mask chassis 512, two connection sockets 532 are arranged, and one socket is arranged on each of the left and right edges of the mask chassis 512. However, as many connection receptacles 532 may be provided, arranged around the mask chassis 512, if desired, depending on the number and location of the mask straps or strap ends. In Fig. 51, the connection socket 532 and the mask headgear 534 are shown as releasable snap-fit connections. However, the connection socket 532 may be any type of conventional connection component. The top edge 540 of the mask chassis 512 generally includes attachment features to the front and rear straps or strap portions of the mask headgear. Depending on the configuration of the front-to-rear straps or strap ends, the attachment features on the top edge 540 may be attachment sockets 532 or other attachment features.

The mask chassis 512 includes a central hole 536 configured and dimensioned to receive the protruding central portion 518 of the cushion/subframe 514 so that the connector 520 can be connected through the central hole 536 of the mask chassis 512 to a suitable air supply tube . Adjacent to the center hole 536 , on the left and right sides of the mask chassis 512 , are adjustment wheel securing portions 542 . The position of the adjustment wheel 542 generally corresponds to the position of the protrusion 528 on the cushion/sub-frame 514 . Each adjustment wheel mounting location 542 protrudes relative to the surrounding surface of the mask chassis 512 and includes a hole such as a threaded hole 544 .

The operation and interrelationship of the adjustment wheel 530, adjustment wheel securing portion 542, and protrusion 528 are best shown in FIGS. 52 and 53, which are schematic cross-sectional views showing the connected mask chassis 512 and cushion in the engaged position. /Part of auxiliary frame 514 showing adjustment wheel 530 which fits in adjustment wheel fixed portion 542 and engages protrusion 528 on auxiliary frame 518 . The adjustment wheel 530 includes a threaded rod or rivet 546 which is secured at one end in a user-twisted head 548 to form a thumbscrew and whose other end is attached or disposed in a hole 544 . A thinner or thinner portion of the wheel 530 is in contact with the protrusion 528 in FIG. 52 . Thus, the cushion/subframe 514 is in a substantially undeformed state that is not affected by the mask chassis. The undeformed state of the cushion/sub-frame 514 may or may not form a good seal with the user's skin because of gaps or insufficient sealing pressure.

To adjust cushion/subframe 514 relative to skin 550 , the user can turn adjustment wheel 530 so that the thicker portion of adjustment wheel 530 moves toward protrusion 528 and contacts 528 . As soon as the thicker portion contacts the protrusion 528, the subframe portion 514 flexes, thereby moving the cushion 516 toward, or closer to, the patient's skin, thereby allowing adjustment of the sealing pressure and/or adjustment of the fit. 53 shows adjustment wheel 530 in a position where it bends cushion/sub-frame 514 towards the skin, thereby eliminating gaps and/or improving the fit/seal between skin 550 and cushion portion 516.

In addition to the adjustment mechanism described above, certain portions of the mask chassis 512 may be locally weakened so that the mask chassis 512 may bend slightly to accommodate various facial shapes. For example, partially weaken the strength of the mask chassis 512 along the line W, so that the mask chassis 512 can be bent. The mask chassis 512 can be made more rigid than the subframe by either using a different material, such as polycarbonate, or constructing a different geometry, such as adding reinforcing ribs, or adding constraints, such as with a headgear tools, or a combination of these methods.

Figure 51 shows an embodiment of the invention in which the mask chassis 512 and cushion/subframe 514 are separate components and the movement of the cushion/subframe 514 relative to the mask chassis 512 is primarily caused by bending. In other embodiments of the invention, however, positioning features are included in the mask chassis and/or the cushion/subframe to allow movement of the cushion/subframe relative to the mask chassis. Additionally, the mask chassis and cushion/subframe may not be formed as separable or separable components, as described in other embodiments.

B. Ribs

1. The first embodiment

Figures 53A-53G illustrate two closely related embodiments of the present invention. Various embodiments are constructed and arranged to help improve the lateral seal force on both sides of the nose. These embodiments are particularly useful on the bridge of the nose. But it can also be used in other areas such as near the nose and lower part of the mouth.

53A-53C illustrate an embodiment in which the frame has a generally triangular shape, in this case configured to support a full face mask cushion, although the frame is suitable for use as a nose cushion s frame. The frame 600 may include other shapes such as generally circular, trapezoidal, or any shape that interfaces with a predetermined area of the patient.

The frame 600 includes a pair of side members 605, each side member including a connector interface 610 having at least one aperture, preferably a plurality of apertures 615. Each aperture 615 is configured to receive an end of a headgear, preferably the aforementioned substantially non-retractable headgear strap. The headgear strap can be connected to any of the holes 615 . In addition, these holes are formed on the sidewall 617 of the connector interface 610 .

As shown in Figures 53B and 53C, the patient's face facing surface 616 includes a pair of ribs 620 which are configured to lie just outside on either side of the patient's nose in use. As shown in FIG. 53B, the ribs 620 are disposed on the bridge region of the patient's nose, but the ribs 620 may also extend along a greater or entire portion of the sides of the patient's nose. The ribs 620 are configured to fit in corresponding grooves or grooves formed on the face cushion (not shown) or on the outside of the cushion. Each rib includes one or more holes 625, which assist in forming a latch between the rib and the cushion and also reduce weight.

In use, the ribs 620 provide a degree of lateral support, helping to maintain a good seal on both sides of the patient. For example, when the tension of the straps is increased, typical pads will tend to undulate sideways outward, thereby increasing the likelihood of compromising the seal or comfort of the cushion. Forming the ribs 620 also helps prevent the cushion from corrugating outwardly, thereby helping to maintain a seal against the sides of the nose.

The frame is configured to be flexible so as to be able to rotate about axis A, bend or deform. Thus, when the headgear is tensioned, the frame 600 can move about axis A, thereby causing the ribs to move inwardly, compressing the sides of the patient's nose. Additionally or alternatively, upon bending, turning or deforming the mask sides, as shown by the arrows in Figure 53C, the top portion 601 of the frame 600 will bend, turn or deform towards the patient's nasal bridge area, as shown by the arrows in Figure 53B shown. In the starting position, the top portion 601 is bent away from the patient's face. Therefore, adjusting the side straps can enhance the seal in the nose bridge area, thereby eliminating the need for the top strap.

As the mask deforms about the primary vertical axis A, the frame tends to straighten along the secondary horizontal axis B. This causes the top end 601 of the frame 600 to move closer to the face so that the cushion presses against the bridge of the nose.

This effect is primarily due to the fact that when the frame is bent about one axis, the parts of the frame that have been bent about the other axis will experience greater strain. So, to minimize the strain in the material, it will straighten the inherent bend to a location of lower strain energy. Straightening the natural curve will bring that part of the mask closer to the face as it leaves the face.

It can be seen that by changing the bending position and orientation of unrelated planes, any desired portion of the frame can be moved toward or away from the frame as satisfactorily as bending the frame in a known plane.

Alternatively or additionally, frame 600 includes one or more lines of reduced strength 630 , such as hinge lines of hinges, such as hinge lines of hinges formed on the top and/or bottom of frame 600 . This weakened wire 600 will allow the frame 600 to move about the axis A more easily.

2. The second embodiment

Figures 53D and 53E are very similar to the embodiment shown in Figures 53A-53C. The main difference is that the connector interface 610 among Figures 53D and 53D includes only one hole 615 for receiving the end of a headgear strap, and the hole 615 includes a slot 617 sized to allow the relative alignment of the straps. The thinner part slides into it, but does not allow the adjustment nut on the strap to pass through. Additionally, as shown in Figure 53E, the ribs 620 do not include holes, unlike the embodiment shown in Figures 53A-C.

Figure 53F shows the frame 600 shown in Figures 53D-E in an operative position resting on a model of a patient's head. Cushion C and elbows are already mounted on frame 600. Figure 53G is a cross-sectional view of the frame.

C. Frame with gasket

FIG. 53H shows another embodiment of the present invention, in this embodiment, the frame 640 is fitted with a gasket 645 . The gasket extends along the bottom 650 of the frame 640 and is disposed under the buckle 655 and at least a portion of the headgear strap 656 disposed on each side 660 of the frame 640 . The gasket 645, which can be made of gel and/or foam, thus provides another level of comfort by preventing possible friction of the clip 655 and/or strap 656 against the patient's jaw.

D. Frame with studs

FIG. 531 shows a first frame member 661 and a second frame member 662 that supports a facial interface member, such as a cushion 663 . The first frame part 661 includes a main opening 664 and a number of first holes 665 . The second frame part 662 includes a plurality of second holes 666 aligned with the holes 665 of the first frame part 661 . The second frame part 662 includes a protrusion 667 configured to be inserted into the main opening 665 of the first frame part 661 .

A number of pegs 668 are disposed between the first and second frame members 661 and 662 . Each peg 668 includes a first end 669 and a second end 670 . The first end is inserted into the first hole 665 and the second end 670 fits in the second hole 666 . Each peg 668 has a spacer or stop 671 . Each peg 668 has a length “L” selected such that its depth relative to the interior of the cushion 663 can be adjusted. For example, the illustrated pegs 668 are of various lengths such that the second end 670 can be threaded through the second hole 666 to a depth into the cushion 663 that is specific to the facial appearance of the patient. As shown, the pegs are secured by a press fit to hold the frames 661, 662 and/or the cushion 643 in place, or the pegs 668 may comprise other structures to secure the cushions or frame components, such as including inverted Hook or side groove.

E. Inflatable Cushion

Figures 53J-53P illustrate an embodiment of the invention in which a frame 170 supports a cushion 172, such as silicone rubber and/or foam. Frame 170 includes one or more headgear attachment locations 171 arranged around the periphery of frame 170 . Cushion 172 includes an inflatable bladder 173 disposed in the nasal bridge region of the patient's nose. The bladder is shown as a single component embedded in the cushion 172, but the bladder may comprise several separate components configured in discrete portions of the cushion 172 at desired locations. For example, the bladder may comprise two bladders disposed on each side of the cushion but not including the apex of the cushion. The one or each air bladder 173 communicates with a material source such as an air source or a gel source, so as to adjust the volume of the air bladder 173 . The or each bladder is configured to reduce or lower the distance between the associated cushion/frame portion and the patient's face. For example, Figures 53L-53P show that the distance of the nasal bridge area gradually decreases as the frame 170 is pressed against the sides. Figures 53L-53P show that the change in shape on either side of the cushion is asymmetrical, although the cushion and/or bladder 173 preferably changes shape in a symmetrical manner, depending on whether the appearance of the patient's nose is symmetrical or asymmetrical .

It is also possible to form the cushion 172 in such a way that when the pressure increases, the ripples of the cushions on both sides are minimized. For example, the outer side wall of the cushion (the side wall away from the patient's nose) can be made of relatively thick wall components so that it is relatively unaffected by pressure increases, thereby reducing the chance of the outer wall corrugating with pressure increases. possibility. Conversely, the inner walls of the cushion (the walls near the patient's nose) may be constructed of relatively thin gauge wall members that allow the walls to bend against the patient's nose, thereby enhancing the seal.

Upholstered

As used in this instruction, the terms "rear" and "rear" refer to the side of the cushion assembly that is adapted to contact the patient's face, while the terms "in front" and "anterior" refer to the side of the cushion assembly that is in contact with the patient's face. That side of the mask shell or main body. As used herein, the term "mask" refers to both nasal masks and full face masks.

54A-54C are an exploded rear view, side view and bottom plan view, respectively, of another known mask, the ACLAIM nasal mask manufactured by Fisher & Paykel (F&P). The ACLAIM nasal mask includes a rigid frame or shell 50 and a cushion assembly including a thin silicone rubber membrane 10 and a foam backing ring 30 that form a seal. The housing 50 includes a channel 51 formed by an inner wall 52 . In use, the foam backing 30 is partially disposed in the groove 51 and extends rearwardly (ie, closer to the patient's face). The membrane 10 is secured to the edge of the housing 50 by a tongue and groove mechanism 60 (FIG. 54D). The foam grommet 30 acts as a support.

As used throughout this specification, the term "ACLAIM upholstery" refers to the upholstery assembly shown in Figures 54A-54D.

A problem with some prior art cushions such as ACLAIM cushions is that these cushions tend to collapse under high pressure, causing the face to easily contact the edge of the frame. This is uncomfortable for the patient and causes indentation or pain on his face.

Referring to Figures 55A-55D, a cushion assembly 100 according to a first embodiment of the present invention includes a silicone rubber membrane 110 and a lower cushion (U/C) 120 similar to that of a MIRAGE(R) cushion. The membrane 110 and the underlying cushion 120 are supported by the underlying cushion flange 140 . The membrane 110 and lower flange 120 may be formed as a single piece with the underlying cushion flange 140 . The membrane 110, lower cushion 120 and lower cushion flange 140 may be made of silicone rubber and may be formed as separate components, or as a single component. Although not shown in the figures, the cushion flange, membrane, and underlying cushion are generally triangular in shape, with the nose bridge area, cheek area, or upper lip area (in the case of a nose mask), or with the chin area (in the case of a full face mask). situation) to match the facial contours of the wearer. As shown in FIG. 55 , the membrane 110 is generally the same shape as the underlying cushion 120 and surrounds the underlying cushion 120 .

Cushion assembly 100 includes a flexible member 130 between membrane 110 and underlying cushion 120 . In a preferred embodiment, the flexible member is a foam insert. Referring to FIG. 55D , the flexible member 130 is disposed between the membrane and the underlying cushion 120 . The flexible member 130 is supported by the underlying cushion 120 and withstands the initial moderate compression of the cushion assembly 100 . A flexible member according to a first embodiment of the present invention is shown in Figures 56A-56F.

The flexible part 130 is an insert made of a soft compressible elastic material such as polyurethane foam. The flexible component 130 can also be made of soft silicone rubber, the hardness of which is, for example, Shore A20 or lower. The flexible member 130 may also be a thermoplastic flexible member.

The flexible member 130 acts like a spring with an initial low spring constant. Except for the flexible member 130, the lower cushion 120 exhibits a relatively stiff spring constant characteristic. In the first embodiment, the corresponding functions of the various layers are: (i) the membrane 110 forms a seal between its outer surface and the patient's face; (ii) the flexible member 130 acts as a compliant layer, thereby preventing premature deflation of the membrane 110. Collapsing on the underlying cushion 120; (iii) the cushion flange of the cushion assembly 100 acts as a support layer, preventing excessive movement of the membrane 110 relative to the face, thereby preventing the face from contacting the frame, the main body of the mask or the shell, Or conversely, the face is prevented from moving relative to the membrane 110, breaking the seal.

The flexible member 130 is shaped along the cavity between the membrane 110 and the underlying cushion 120 of the cushion assembly 100 . The gap of the flexible member 130 to the membrane inner surface 115 is such that the membrane 110 can still corrugate outwardly, sealing against the patient's face.

Figures 57A-57C illustrate the mechanical properties of the cushion assembly 100 (Figure 57A) and compare them to those of the MIRAGE(R) cushion (Figure 57B) and the ACLAIM cushion (Figure 57C). The y-axis represents the relative cushion height h/ho, which is 1 when the cushion assembly 100 is at its original height ho. If the cushion assembly 100 is compressed to half its original height, the relative cushion height is 0.5. The x-axis represents the pressure F acting on the cushion assembly 100 . The force F may be a resultant force acting on the cushion assembly 100 applied between the mask shell and the patient's face.

See Figures 58 and 59A-59F. The cushion assembly 200 of the second embodiment of the present invention includes a membrane 210 , a flexible lower cushion, a flexible member 230 and a lower cushion flange 240 . The membrane 210 and the underlying cushion 220 may form a single part with the underlying cushion flange 240 . The bottom cushion flange 240 is secured to the mask frame or shell 250 at its rear edge. In a preferred embodiment, the flexible member 230 is a foam insert. The flexible component 230 can also be made of silicon rubber.

60A-60C illustrate the mechanical characteristics of the second embodiment of the cushion assembly 200, the MIRAGE(R) cushion and the ACLAIM cushion, respectively, of the present invention. Figure 60D shows a comparison of three cushions in one coordinate system. The y-axis represents the relative cushion height h/ho, while the x-axis represents the pressure F acting on the cushion. The pressure is expressed as a percentage of the maximum pressure acting on the cushion component.

Referring to FIG. 60A, in the initial region corresponding primarily to the membrane 210, a pressure of about 20% of the maximum force is applied, and the cushion height decreases to about 95%. At a second region corresponding to the flexible member 230 of the cushion assembly 200, the compression increases from 95% to 80% when a pressure of about 60% of the maximum force is applied. In the third region corresponding to the lower cushion 220, the force is increased to 100% of the maximum pressure, compressing the cushion assembly 200 only slightly.

Figure 60B shows the mechanical properties of the MIRAGE(R) cushion. Applying a compressive force of about 50% of the maximum pressure in the area corresponding to the membrane resulted in a compression of about 75%, further increasing the compressive force resulted in only a slight decrease in the relative height of the cushion corresponding to the compression of the underlying cushion.

Figure 60C shows the mechanical properties of the ACLAIM cushion assembly, starting compression of about 90% can be achieved relatively easily with relatively little force. Subsequent further increases in pressure resulted in that application of about 30% of the maximum pressure would cause significant compression of the foam insert. Applying pressure above about 30% of the maximum pressure produces little or no compression on the ACLAIM cushion assembly because the foam insert is fully compressed on the mask shell.

Figure 60B shows a comparison of the first three curves in one coordinate system.

Fig. 61 is a schematic diagram showing the functions of the cushion assemblies 100, 200 of the first and second embodiments by comparing the flexible members 130, 230 and the lower cushions 120, 220 to springs, respectively. The spring constant of the flexible member members 130 , 230 is smaller than the spring constant of the underlying cushions 120 and 220 . As shown in Figure 61, the flexible members 130, 230 act as soft springs that initially absorb the pressure of the cushion assembly. The flexible member 130, 230 enhances the flexible feel of the cushion assembly 100, 200 and increases the conformity of the cushion assembly 100, 200 to the patient's surface, thereby improving the seal and reducing or eliminating air leakage.

As the pressure on the cushion assemblies 100 and 200 increases, the more rigid underlying cushions 120, 220 will begin to compress. The lower cushion 120, 220 reduces or eliminates the possibility of the patient's face contacting the mask shell.

Referring to FIG. 62 , an upholstery assembly 300 according to a third embodiment of the present invention includes a membrane 310 extending from an underlying upholstery flange 340 . The rear end of the bottom cushion flange 340 is secured to the mask shell 350 . A flexible member 330 is disposed between the membrane 310 and the underlying cushion flange 340 . The flexible member 330 of this embodiment is generally taller or deeper than the first and second embodiment flexible members. The flexible member 330 in this embodiment is made of one material. The cushion flange 340 does not include the underlying cushion. In this embodiment, the membrane 310 achieves the primary seal and is supported by a flexible member 330 which distributes the pressure in various locations resulting in a more comfortable mask system.

Additional views of the flexible member 330 are shown in FIGS. 63A-63E . In this embodiment, the flexible member 330 includes a plurality of portions 331, 332, 334, 335 with different properties (force-deformation properties). As shown in Figure 63B, which shows the rear side of flexible member 330, portions 333 and 334 may be placed in the nasal bridge area of the mask. The portions 333 and 334 are of the same size and shape, but have different spring constants (ie, stiffness) to accommodate differences in the size and shape of individual patient faces. It should be noted that portions 331, 332, 333 and 334 have different sizes, shapes and spring constants in order to accommodate differences in the size and shape of individual patient faces. It should also be noted that any number of sections may be used.

The flexible member 330 is supported by a rigid cage 335 . The holder 335 holds the flexible member 330 when the cushion assembly 300 and the mask are assembled. The flexible member 330 and cage 355 can be combined together as a subassembly. The cage 355 also includes an extension with an elbow securing clip 360 . The elbow pipe fixing fixture 360 fixes the elbow pipe 370 required for air supply from the air source. Figures 64A-64E show additional views of the cage.

Referring to FIG. 65, a cushion assembly 400 according to a fourth embodiment of the present invention includes two-layer or three-layer components. The first layer consists of upholstered flanges 440 . The front side of the cushion flange 440 is adapted to attach to the shell of a mask. The second layer consists of a flexible member 430 attached to a cushion flange 440 . The flexible member 430 defines the shape of the cushion and forms the face contacting member. The flexible part 430 has a third layer consisting of a surface layer 460 .

The first layer (upholstered flange 440) is a rigid layer of urethane rubber (no foam). The second layer (flexible member 430) is made of urethane foam or soft silicone rubber. The third layer (skin layer 460) consists of a silicone rubber skin. The thickness of the surface layer 460 is preferably 0.2-0.6mm, and the thickness is either uniform, or varies according to the load, or according to the degree of deformation required.

Referring to FIG. 66, a cushion assembly 500 according to a fifth embodiment of the present invention includes two-layer or three-layer components. The first layer consists of upholstered flanges 540 . The front side of the cushion flange is adapted to attach to the shell of the mask. The cushion flange 540 includes a support portion 545 extending from the front side to the rear side. The support portion is flexible and acts like an underlying cushion. The second layer consists of a flexible member 530 which is attached to the cushion flange 540 and surrounds the support portion 545 . The flexible member 530 defines the shape of the cushion and forms the part that contacts the face. The flexible part 530 has a third layer consisting of a surface layer 560 .

The first layer (upholstered flange 540) is rigid urethane rubber (no foam). The second is made of urethane foam or soft silicone rubber. The third layer (skin layer 560) consists of a silicone rubber skin layer having a uniform or varying thickness as described above.

In use, the flexible member 530 begins to compress when it contacts the wearer's face and applies pressure. As the pressure increases, the flexible member 530 is further compressed until it is completely pressed against the supporting portion 545 . Further application of pressure will result in compression of support portion 545 . The flexible member 530 and the support portion thus act as two springs in a manner similar to that shown in FIG. 61 .

Referring to FIG. 67, a cushion assembly 600 according to a sixth embodiment of the present invention includes a first layer and a second layer. The first layer consists of a cushion flange 640, the front side of which is bonded to the mask shell. The second layer consists of a flexible member 630 attached to a cushion flange 640 . The flexible part 430 defines the shape of the cushion and constitutes the part that contacts the face.

The first layer (upholstered flange 640) is a rigid polyurethane rubber (no foam) layer. The second layer (flexible member 630 ) is made of foam, and includes a first portion 631 with relatively low rigidity and a second portion 632 with relatively high rigidity. Using foam materials of different densities to form the flexible member, different rigidities can be obtained, as shown by the oppositely spaced points in the first and second portions 631 and 632 . The flexible part 630 is a single part with different densities, or several parts with different densities. Although the flexible member 630 is shown in FIG. 67 as having two different stiffnesses (densities), it should be appreciated that the flexible member 630 may have more than two stiffnesses (density). As shown in FIG. 67 , the second portion 632 includes a region 632a that extends beyond the cushion flange 640 , thereby preventing the wearer's face from pressing against the cushion flange 640 .

In use, the first portion 631 of the flexible member 630 begins to compress upon contact with the wearer's face and upon application of pressure. As the pressure increases, the first portion 631 is fully compressed while the second portion 632 begins to compress. Since the second portion 632 is harder than the first portion 631 , the relative height of the cushion assembly 600 is lowered in the second region 632 less than the first region 631 by applying pressure.

Although not shown in FIG. 67, it should be appreciated that cushion assembly 600 may have a third layer, such as a skin layer.

68 and 69 show another embodiment of the present invention. The foam cushion 700 is fixed on the frame 705 . The frame includes holes 710 through support rods 715 . The hole 710 and the support rod 715 are threadedly engaged with each other so that the position of the head portion 720 of the rod 715 can be moved, as indicated by the double arrow. As shown in FIG. 69, the frame 705 has an adjustment knob 725 to allow the rod 715 to move. Although frame 705 is shown to include only one adjustment rod 715, multiple such adjustment rods may be provided. Adjusting the position of the rod 715 can change the configuration of the cushion within a given pressure range.

70-79 are cross-sectional views showing other foam cushion embodiments of the present invention.

In FIGS. 70 and 71 , the interior of the foam cushion 729 includes a spring member 730 . The amount of cushion material over spring member 730 may vary depending on the position of the cushion relative to the patient's face. For example, in problematic or sensitive sealing areas, the cushion can be deformed so that the spring member 730 can be embedded deeper in the cushion, whereby the cushion itself can be used to achieve a seal with the problematic or sensitive area, while the spring member The effect, if any, is not too great. One advantage is that the spring member 730 is fully embedded and invisible, so it feels simple to look at, which may affect the patient's compliance with the treatment.

72 includes a cushion 732 made of foam and a stretchable membrane 734, preferably made of silicone rubber, disposed on the inner surface of the cushion 732. The stretch film 734 easily conforms to the patient's face. FIG. 73 is a device with a membrane 736 on the outside of a support 732 .

FIG. 74 is a device in which a cushion 732 has a channel 738 communicating with a chamber 740 disposed within the interior of the cushion 732 . This channel 738 communicates with a source of compressed air or other substance, such as a source of gel, so that the stiffness characteristics of the cushion can be varied.

Figures 75A, 75B and 79 show different cross-sections that create at least two spring rates when the cushion is compressed. In FIGS. 77 and 78 , the cushion 732 includes at least three spring rates during compression, and in FIG. 77 the cushion 732 includes three layers L1 , L2 and L3 , each layer having a different spring rate. 78 has a first spring rate when the head portion 747 is pressed into the groove 748, a second spring rate when the central portion 749 is pressed into the second groove 75, and a second spring rate when entering the bottom portion 753. has a third spring stiffness coefficient.

[00242] FIG. 76 shows a cushion 732 with indentations 756 that help maintain a seal between the cushion and the patient's surface, for example, by suction.

An advantage of a foam insert as a flexible component is that foam is more easily compressed than silicone rubber, so the cushion assembly of the present invention comprising a foam insert can more evenly distribute the forces of the headgear.

The advantage of silicone rubber as a flexible part is that it is easy to clean and is more biocompatible with the patient. It should be noted that in the above embodiments the individual components, namely the membrane, the flexible member and the cushion flange act as a kind of mechanical spring. The above-mentioned embodiments can be combined, for example, the flexible parts of the first and second embodiments can have a plurality of regions with different rigidities (density), or each part of the flexible part of the second embodiment can have a plurality of regions with different rigidities (density) . The desired level of comfort can be achieved using various combinations of the above described membranes, flexible members and cushioned flanges.

The flexible part can be made of viscoelastic foam with constant density or with variable density to achieve the desired effect. The flexible part can also be produced from an open-cell or closed foam material with constant density or with multiple densities. The flexible member may or may not be covered with a skin.

A mask assembly including a cushion assembly according to one embodiment of the present invention may employ a four-strap mask similar to that of the ULTRAMIRAGE ^™ mask system manufactured by Res Med Limited.

A mask assembly including a cushion assembly according to an embodiment of the present invention may employ a headgear buckle as described in US Patent No. 6,374,826, the disclosure of which is incorporated herein by reference.

An advantage of the mask system cushion assembly of the present invention is increased user comfort. For those who require a lot of belt tension to achieve a seal, this may be due to the force being evenly distributed. The flexible member also helps to maintain the shape of the membrane and maintain an effective seal during the night when the user is involuntary.

Other advantages of the cushion assembly of the present invention include ease and low cost of manufacture. The cushion assembly of the present invention is less complex than prior art cushions such as the ACLAIM cushion, which is a three-part cushion that requires assembly prior to being secured to the mask.

Yet another advantage of the present invention is that the flexible member causes less membrane distortion, which allows the physician/clinician to install the mask in less time and achieve a more reliable seal.

A further advantage of the present invention is that a more stable seal can be achieved by placing a flexible member under the membrane. The flexible member also has less variation in leakage velocity between the face and cushion due to reduced movement of the mask. In this way, the treatment provided by the dual pressure machine is improved.

In order to provide the correct force, the flexible part should have the proper force-displacement characteristics, this requirement is that the part should be soft enough to initially bend to match the facial organs, but should not be pressurized by the rigid part due to the padded flange, It is completely compressed, making the user uncomfortable.

In some of the embodiments described above, the cushion is disposed on the frame with an adhesive, and in another embodiment shown in FIG. 80, the cushion is secured to the frame with mechanical fasteners. In the example of FIG. 80 , a mask assembly 900 includes a body portion 902 and a cushion 904 secured thereto, the cushion 904 including a polyneoprene cushion 906 covered with a continuous membrane 908 of silicone rubber, for example. The flexible portion 910 is arranged along the outer periphery of the main body portion 902 for the reasons described above. The main body portion 902 and the membrane 908 are formed from a single piece in this example. The membrane 908 includes an inner peripheral shoulder 912 and an outer peripheral shoulder 914 that engages a surface 916 of the flexible frame 910 and wraps around the edges of the flexible frame 910 . Alternatively, the peripheral shoulder can be said to contain a groove that receives the outer edge of the flexible frame 910 . Likewise, the inner peripheral shoulder includes a groove that receives the inner peripheral edge of the flexible frame 910 . In other words, part 908 can be snapped onto the edge of frame 910 .

Snapping the edge of the pad to the frame eliminates the need for bonding the neoprene pad to the frame, although this bonding is used between the neoprene pad and the silicone rubber membrane. This configuration provides excellent integrity of the assembly, creates a more secure bond between all components, and eliminates the problems associated with chemical compatibility between the neoprene cushion and nylon frame that require bonding.

The mask assembly is strong enough to withstand the forces exerted by extreme conditions, making it more reliable and safer for the patient. Membrane 908 provides a sealed air path with low air leakage.

Figure 81 shows relaxation curves for foam materials used in flexible parts of the present invention.

The following table lists exemplary properties of foam materials suitable for use in flexible parts of all embodiments of the present invention: characteristic value density 0.1752(g/cm ² ) at 25% CLD 1.054(N/cm ² ) At 65% CLD 3.375(N/cm ² ) Sag coefficient 3.20 IHF 4.36 Recovery rate% 57

The following definitions are taken from prior publications, but the above tables showing properties are in units of measurement other than those used for the above definitions.

Density is the weight per unit volume of foam, expressed below in pounds per foot ³ (pcF), but above in g/cm ³ . Typical densities of flexible polyether urethane foams range between 1-4 pcf. This density is not a measure of stiffness, unlike latex rubber foam. Higher density foams generally have better quality and performance for a given load bearing requirement.

Compression load deflection (CLD) (compression load defletion) is also a measure of bearing load, generally expressed as pounds per inch ² (psi) under a certain percentage of deformation. In this test, the entire sample is compressed, and the measured value is the same as Foam thickness is irrelevant as long as the thickness does not exceed the length and width. CLD is used to indicate the hardness of some specialty foams and some semi-flexible foam hardness specifications. These values can also be used to determine the change in load bearing capacity under various humidity or heat aging conditions.

Indentation load deflection (ILD) under load (indenation load deflection) is a measure of load bearing capacity expressed as pounds load/50 ⁱⁿ² at a given foam percent deflection. To obtain this value, a 50 inch square disc (a) is pushed into the top surface of the foam, stopped at a given state of deformation, and the load or scale is read. For example, a 25% ILD of 30 means that a 30-pound load is required to compress a 4-inch thick foam board to 3-inch thickness, and the greater the load, the stiffer the foam will be. In this test, the size of the foam sample is larger than the size of the circular plate, typically 15 by 15 inches for flat sheets of foam.

In some specifications, other plate configurations and dimensions are used to define the ILD. ILD, sometimes called RMA (Rubber Manufacturing Association), is derived from the same measurement for latex foam. The recommended procedures for characterizing flexible foam specifications are: USU (Urethane Slab Uncored); USC (Urethane Slab Cored); UMU (Urethane Molded Uncored); UMC (Urethane Molded Cored). The value following this code indicates 25% ILD, for example USU-30 refers to a centerless planar foam material with a 25% ILD of 30, when the measured value is affected by the original thickness of the foam material, the original thickness of the foam material must be shown. (See BASF Wyandotte Technical Advisory, "Effect of Foam Thickness on ILD".)

The sag factor is the ratio of 65% ILD to 25% ILD, indicating the quality of the cushion. Higher values indicate resistance to bottoming out. Foams with low sag coefficients typically "bottom out" and perform poorly. Other terms for this coefficient are SAG coefficient and SAG modulus.

Initial Factor of Hardness (IFH) is the ratio of 25% ILD to 5% ILD. This coefficient determines the surface feel. Flexible or soft-surfaced foams have higher values, while stiff-surfaced foams have lower values. Another term for initial stiffness factor is comfort factor.

When measuring ILD, it is common to read values at 25% deflection, 65% deflection, and back to 25% deflection after the load is removed. The initial 25% deformation value divided by the return to this 25% deformation value when the load is removed is the recovery, expressed as %. For cushioning, a higher recovery rate is required, while for vibration absorption, a low recovery rate is required. Foams with low recovery rates are sometimes referred to as "non-resilient".

Indentation residual gauge load (ERGL) is another measure of load carrying capacity expressed as inches of a certain load. The same 50 square inch circular plate was used to measure the ILD, but the plate was loaded with a certain load. Normal loads are 25 lbs, 50 lbs or 75 lbs. IRGL values are expressed in inches. The original thickness of the foam must be known in order for the resulting value to be meaningful. This metric is often used to specify automotive foam specifications. There is no readily available correlation between ILD and IRGL measurements.

Guide factor is the ratio of 25% ILD to density, a term used to determine the relative stiffness of foams of different densities. The closer the densities are, the better the comparison. When the densities are different, the foam with the highest Guide factor has a cost advantage. But the performance is not necessarily good. Another term for Grid factor is normalized ILD.

Indentation modulus (IM) is the load required to produce 1% indentation within the range of 20% ILD and 40% ILD. The slope of this line depends on the ability of the cell foam wall to resist bending.

Resilience is a measure of the elasticity or resilience of a foam. In this test, a steel ball is dropped on the foam and the rebound is expressed as a percent resilience, and like recovery, the required value depends on the application. Resilience can be misleading for very soft foams, because under the action of the ball, the foam will contact the floor. Thus, even though the foam is "flexible" or elastic, very low resilience values are obtained. Ball bounce is another term for this property.

Tensile strength is a measure of the amount of stress required to stretch a foam material to break and is expressed in pounds per ^inch2 (psi) Tensile strength is used as a quality control and a common test is in heat aging Thereafter, changes in tensile strength were measured.

Elongation is generally measured at the same time as tensile strength is measured. Stretch is a measure of the amount of elongation that a foam can stretch before it breaks, expressed as a percentage of the original length.

Tear strength is a measure of the force required to continue tearing a foam after it has begun to crack or break, expressed in pounds per linear inch (pli, or more commonly, pi). This property is important in determining the suitability of foam materials in applications requiring the material to be sewn, nailed or "hog-ringed".

Compression set is a measure of the deformation of a foam after it is held in compression under controlled conditions of time and temperature. Standard conditions are 22 hours at 158. In this test, foam is compressed to a given thickness expressed as a percentage of its original thickness. Compression set is most commonly expressed as a percentage of initial compression.

Fatigue is a measure of the loss of load bearing capacity under simulated conditions of use, generally expressed as a percentage load loss. The two most common fatigue tests are static fatigue testing and roller shear fatigue testing.

In a static fatigue test, the foam is compressed to 25% of its original thickness at room temperature for 17 hours and the ILD loss will be calculated, expressed as a percentage of the original value.

In the roller shear fatigue test, a roller longer than the width of the foam is rolled back and forth over the foam. The roller is mounted in a laterally movable position to apply shear force. The test method differs when a constant deformation set point or constant roll weight is applied. Follow the instructions of the test method to calculate the loss of ILD or IRGL.

Air flow is a measure of the porosity, or openness, of the foam and is expressed in cubic feet of air per minute (cfm). Use a vacuum to draw air through the foam as described in the ASTM method, or use the device, "BWC Portable Air Flow Measurement Device" and "BWC Portable Air Flow Measurement Modified Device," as described in the BASF Wyandotte Technical Advisories report, using Air is blown through the foam.

There are many other foam properties and test methods. Many of these have been developed for the particular aspects considered. Additional definitions of terms and descriptions of test methods can be found in ASTM Standard Methods D-1564 and D-2406 in the Specifications for Specialty Foam Materials section.

While the invention has been described in terms of presently most suitable preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments, but on the contrary, the invention includes modifications and equivalent arrangements within the spirit and scope of the invention.

Claims (33)

1. A mask assembly of a positive pressure air supply device, comprising: a mask body assembly constructed and arranged to sealingly contact at least a portion of the patient's face, thereby providing pressurized breathing gas to the patient; a mask frame connected to the mask cushion, the mask frame having one or more receiving parts for receiving the joining portion with the securing mechanism; Headset, including: one or more straps, each of the one or more straps having a strap securing mechanism constructed and arranged to engage a receiving member of the mask frame; A flexible tensioning member is attached to the one or more straps to automatically adjust the tension of the one or more straps based on the pressure of breathing gas supplied to the patient. 2. The mask assembly of claim 1, wherein the one or more straps are substantially non-retractable. 3. The mask assembly according to any one of claims 1 and 2, wherein the flexible tensioning member is an inflatable bladder, such as an occipital cushion or air bag, connected to the one or multiple bands. 4. The mask assembly of claim 3, wherein the inflatable bladder is inflatable with a portion of the pressurized breathing gas delivered to the mask assembly. 5. The mask assembly of any one of claims 3 and 4, wherein the pressure in the inflatable bladder increases as the pressure of breathing gas delivered to the patient increases. 6. The mask assembly according to any one of claims 3-5, further comprising a conduit having two ends, a first end adapted to be connected to a breathing gas conduit, a second end adapted to be connected to an inflatable bladder, Gas communication is thereby established with the breathing gas conduit. 7. A method of controlling strap tension in a non-invasive positive pressure supplied air mask: connecting the flexible tensioning element to the straps of the mask; The flexible tensioning member automatically increases the tension of the strap as the pressure of the breathing gas delivered to the patient increases. 8. The method of claim 7, wherein the flexible tensioning member is an inflatable bladder, such as an occipital cushion or air bag. 9. The method of claim 8, wherein causing the flexible tensioning member to automatically increase the tension of the strap includes automatically inflating the inflatable bladder when the pressure of breathing gas delivered to the patient increases. 10. A substantially non-retractable headgear assembly constructed and arranged to be connected to a face mask of a positive pressure air supply, the headgear comprising: one or more substantially non-retractable straps; An inflatable bladder, such as an occipital cushion or bladder, is in force-transmitting relationship with one or more straps. 11. A mask assembly for a non-invasive positive pressure air delivery device, comprising: a mask frame having substantially rigid side sections connected by a soft bottom and a soft top; a mask body assembly connected to the mask frame and movable relative to the frame; Headgear constructed and arranged to be releasably connected to a mask frame, the headgear including a flexible tensioning member in force-transmitting relationship with the frame, the flexible tensioning member configured to be adapted to freely Automatically adjust the tension of the headgear. 12. The face mask assembly of claim 11, wherein the flexible tensioning member is an inflatable bladder, such as an occipital cushion or air bag. 13. A mask assembly for a non-invasive positive pressure air supply device, adapted to be placed on a patient's face, comprising: a mask frame having substantially rigid side portions joined by soft bottom portions and top portions, the top and bottom portions defining a longitudinal axis; A mask body assembly connected to the mask frame; mask cushion, connected to the mask body; headgear comprising at least one strap constructed and arranged to be positioned along the side of the head in use; Wherein the mask frame is elastically deformable around the patient's face about the longitudinal axis so as to adapt to the configuration of the patient's face and is secured to at least one strap. 14. A method of sealingly maintaining a mask on a patient's face, comprising: Place the occipital air cushion over part of the head and/or neck; Passing the strap over the air cushion, the strap stretches forward and attaches to the mask; Inflate the cushion with a pressure P _bladder that is an affine function of the mask pressure P _mask : P _bladder ＝P ₀ +A _mask P _mask In the formula, _P0 is the positive pressure, which is large enough to make the mask seal at the lowest operating pressure, and A _mask is the contact area between the air cushion and the belt at the rear and the contact area between the air cushion and the back of the head at the front The smaller of the contact areas. 15. The method of claim 14, wherein the air cushion is inflated with a pressure that is an affine function of mask pressure, the method comprising the steps of: The mask pressure is measured with a pressure sensor, which generates a signal proportional to the mask pressure; Apply this signal to an amplifier with adjustable gain and offset; Applying the output of the amplifier to a voltage-controllable pressure source; inflating said air cushion with gas from said pressure source; Adjust the above deviation so that the cushion can achieve sealing under the minimum required pressure; The above gains are adjusted so that the mask can achieve a seal at the highest required pressure. 16. The method according to any one of claims 14 and 15, characterized in that the controllable pressure source produces a pressure P _c =K _c V if the signal V _pt of the pressure sensor is V _pt =K _pt P _{mask c} . The projected area of the contact area between the mask and the face in the rear direction is A _mask , the projected area of the contact area between the belt and the back surface of the air cushion in the front direction is A _bladder , and the force required to achieve sealing when the pressure is zero is F ₀ , then The amplifier produces an output voltage: V _out ＝F ₀ /A _bladder +A _mask /A _bladder K _c /K _pt V _in 17. The method of any one of claims 14-16, wherein the air cushion is inflated with a pressure that is an affine function of mask pressure, the method comprising the steps of: The mask is connected by a first hose to a first cylinder comprising a first piston which in turn is connected by a connecting rod to a second piston in a second cylinder which is connected by a second hose to the The air cushion biases the above-mentioned connecting rod to inflate the above-mentioned air cushion sufficiently so that the mask can achieve sealing under the minimum predetermined use pressure. 18. A device for sealingly maintaining a mask on a patient's face, comprising: a first set of extensible straps extending forwardly from the back of the head to the mask, tensioning said straps sufficiently to maintain said mask sealingly against the face at minimum use pressure; a second set of non-retractable straps, still extending forward from the back of the head to the mask, the second set of straps being positioned above the first set of straps; An inflatable occipital air cushion is placed on the back of the head between the first and second sets of straps, the air cushion being in fluid communication with the air in the mask. 19. A mask assembly for applying a non-invasive positive pressure air supply to a patient, comprising: a frame comprising a main body including at least one aperture shaped to receive delivery of pressurized breathable gas, said frame including at least one selected portion attached to the main body, said selected portion being positioned relative to the main body Adjustable; Cushion, mounted on a frame, configured to form an interface with a patient, upon application of positive pressure, said cushion exerts a force against the patient which can be determined according to 1) at a given value of said positive pressure The position of the selected frame portion relative to the body; and/or 2) a change in the positive pressure, is adjusted. 20. The mask assembly according to claim 19, further comprising at least one headgear connecting portion configured on the frame portion, the frame portion can be moved according to the tension of the headgear belt, so that when in use , which can adjust the force acting on the sides of the patient's nose and/or face. 21. The mask assembly of claim 19, wherein the frame includes an adjustment mechanism comprising at least one, preferably a plurality of, spaced apart adjustment knobs that can be adjusted to vary the distance between the main body and the frame portion. relative position. 22. The mask assembly of claim 19, wherein the selected frame portion includes a flexible member that supports the cushion. 23. The mask assembly of claim 19, wherein the main body and selected frame portion are formed as two separate components that are interconnected. 24. The mask assembly of claim 19, wherein the main body and the selected portion are movable by a cam mechanism. 25. The mask assembly of claim 19, wherein the cushion includes at least one component therein that is inflatable so that the effective stiffness and/or effective fit with the patient can be adjusted. 26. The mask assembly of claim 25, wherein the inflatable member is configured to selectively adjust the size of the nasal bridge region of the cushion. 27. The mask assembly of claim 19, wherein the selected frame portions include respective frame side portions of the frame fabricated from a flexible material. 28. The mask assembly of claim 19, wherein the cushion includes at least one component that provides multiple coefficients of stiffness to the cushion as the applied force varies. 30. A mask cushion assembly for treating sleep irregular breathing, the cushion assembly comprising: a cushion flange of relatively rigid material comprising a first side adapted to be attached to the mask body and a rear side opposite the first side; a lower layer of cushion, connected to the cushion flange and extending toward the rear side, the lower layer of cushion has a first rigidity; a membrane attached to the cushion flange and extending toward the rear side, the membrane having a shape substantially matching the shape of the underlying cushion and surrounding the underlying cushion, the membrane having a second stiffness less than the first stiffness, the membrane being suitable for Designed to fit the wearer's face and, when attached, form a seal between the mask and the wearer's face; A flexible member is disposed between the underlying pad and the membrane, the flexible member has at least a third stiffness that is greater than the second stiffness and less than the first stiffness. 31. The cushion assembly of claim 30, wherein the flexible member is formed of multiple parts. 32. The cushion assembly as claimed in any one of claims 30 and 31, wherein the flexible member is composed of foam material and the flexible member is composed of silicone rubber. 33. A mask software component for treating sleep irregular breathing, the cushion component comprising: a cushion flange made of a relatively rigid material, the cushion flange comprising a first side adapted to be attached to the mask assembly body and a rear side opposite the first side; a membrane attached to the cushion flange and extending toward the rear side, the membrane having a first stiffness, the membrane being adapted to contact the patient's face and upon contact, form a seal between the mask and the wearer's face; a flexible member disposed between the membrane and the cushion flange, the flexible member having a second stiffness at least greater than the first stiffness; The cage is in contact with a flexible member supported by it, which is disposed between the cushion flange and the cage. 34. A mask cushion assembly for treating sleep irregular breathing, the cushion comprising: a first layer comprising a front side adapted to be attached to the body of the cushion and a rear side opposite the first side; The second layer, connected to the first layer and extending from the front side to the rear side of the first layer, defines the shape of the cushion and is adapted to contact the wearer's face, and when in contact, between the mask and the wearer. Forms a seal between the user's face and is compressed when force is applied to the cushion assembly.

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