Respirator mask

Abstract

A mask for supplying gas under pressure to an airway of a human including: a flexible manifold shell, being made of a flexible material, the manifold including means for connection to a gas delivery pipe. There are at least two side walls which are at least partially formed by portions of the manifold shell; a flexible face contacting element defining an orifice to accommodate the nose of the human; a first connecting strap having a first end connected to the mask and a second end connectable to a mask retaining strap; and a second connecting strap having a first end connected to the mask and a second end connectable to the mask retaining strap. The first strap and the second strap engage respective side walls of the mask for distributing opposing distortional forces to a substantial portion of the respective side walls when the mask is in use. The connection of the straps to the mask allow forces exerted by the first and second straps are capable of deforming the manifold at least along X and Y axes to create a variety of different mask / orifice shapes. The manifold of the mask has a manifold height and a centroid. The first and second straps engage the mask along a connecting length thereby joining the first and second straps to respective side walls of the mask so that an axis through the centroid normal to the Y axis, intersects with at least part of each strap.

Description

FIELD OF THE INVENTION[0001]This invention relates to a mask, in particular to a mask for supplying gases, typically air or oxygen, to the airways (nose or no and mouth) of humans. Such masks are often referred to as “respirator masks”. Such masks are particularly suited to applying continuous positive airway pressure (CPA) to patients for treatment of sleep apnoea, however the invention is not in any way limited to masks for that use only. More particularly the invention relates to a face mask including straps which terminate in webs which engage opposing walls of the mask and which have a contact length which transfers in use loadings applied to the straps through to the mask allowing the mask to displace on a users face in an X, Y or Z direction and without breaking a seal created between a face contacting part of the mask and the mask.BACKGROUND OF THE INVENTION[0002]In general, conventional respirator masks consist of a face contacting part which defines an orifice and which fi...

AI Technical Summary

Benefits of technology

[0013]In a broad aspect, the present invention provides a mask which has a flexible manifold and face-contacting components which can be distorted into different shapes to suit differing facial contours when applying tensile forces to the mask, typically by means of a straps and a harness. The nature of the connection between the straps and the mask is such that loadings applied to the mask via the straps are distributed so that distortions of the mask under load will not compromise the required air seal between the users face and the face contacting part of the mask.

Problems solved by technology

In some cases, patients find them uncomfortable.

In particular, the relatively thicker sections of the face contacting part can cause discomfort when pressed against a patient's face at the pressures required to create a gas tight seal.

This is a particular problem where high therapeutic gas pressures are required.

In other cases, such masks do not fit properly, for example where the mask is too narrow in the X-Y plane for the patient's nose.

Often, the bulky rigid manifold and relatively high attachment points of the harness cause a patient's line of vision to be impaired and this can cause a degree of claustrophobia in some patients.

An additional problem arises from the use of rigid materials in mask construction, particularly for the manifold.

When a patient wearing a mask having a rigid manifold turns in bed and contacts an object such as a pillow, reaction forces from the pillow tend to push the manifold laterally and lift the face contacting part from the patient's face thereby breaking the gas tight seal and causing an air leak which prevents optimum therapy being delivered to the patient.

Hard plastic components may also cause pain or discomfort if they are pushed hard against a patient's skin during sleep.

The use of hard components also makes it difficult for a patient to sleep on their stomach, because pressure on the manifold tends to result in air leakage or patient discomfort.

Such masks can be difficult for some patients to dismantle and clean.

In addition parts can become broken or lost.

A mask made from many parts is typically more expensive to produce than a mask having fewer parts, due to increased moulding costs for the many different parts, and assembly and inventory costs.

A further problem with existing conventional masks is that a substantial number of patients leak gas from their mouth during positive gas pressure therapy.

However one of the problems with these masks for some patients is that they do not succeed in fully preventing gas leakage from the patient's mouth.

Often gas leakage is preceded by stretching and ballooning of the patient's cheeks, which tends to substantially change the facial contours adjacent the face sealing portion of the masks.

This significant facial deformation has the effect of breaking the gas tight seal around the mask, since the face contacting portion of the mask presents a relatively rigid sealing surface incapable of adapting to such large changes in facial contours.

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