GB2390979A

GB2390979A - Noise damping mask

Info

Publication number: GB2390979A
Application number: GB0315507A
Authority: GB
Inventors: Joseph Anthony Griffiths
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-07-12
Filing date: 2003-07-02
Publication date: 2004-01-28
Also published as: GB0315507D0

Abstract

An oro-nasal mask (4) moulded from a natural or synthetic rubber material having an inside surface coated with a damping material (8) to reduce vibration in the mask and thereby suppress noise and interference generated during breathing in hoses connected to the mask which could be sensed by a microphone (6) when mounted in the mask. The noise damping material may be a natural or synthetic rubber or polyurethane having a Shore Hardness in the range of 5-50.

Description

- 1 Noise Damping Mask 2390979 this invention relates to an improved oro-

nasal mask for fitting to an oxygen mask or a respirator which incorporates means to suppress "noise" generated s during breathing which can interfere with a microphone mounted therein.

Oxygen masks or respirators generally include an oro-nasal mask which makes a seal with the wearer's face and the breathable gas is supplied to the interior of the oro-nasal mask. A microphone is usually mounted in the oro-nasal mask to lo enable the wearer to make radio contact with other people. The flexible moulded oro-nasal mask has an inwardly directed flexible lip which surrounds the wearer's nose and mouth to make the seal with their face and includes a valving arrangement allowing the breathable gas to be drawn in to the mask by the wearer and exhalate to be expelled therefrom. The microphone is normally Is mounted in the front of the oro-nasal mask directly opposite the wearer's mouth.

Because of its construction and particularly due to the fact that the microphone is mounted directly in the moulded oro-nasal mask, "noise" caused: 20 (a) by vibrations generated during breathing; (b) by vibrations transmitted into the mask through the walls of the breathing hoses connected thereto; (c) by vibration generated and caused by the oxygen delivery system, is picked up by the microphone and can interfere with the ability of the wearer to 2s communicate by radio with other people and is therefore highly undesirable.

It is an object of the present invention therefore to provide an oronasal mask for use with an oxygen mask or respirator which overcomes or substantially reduces these problems.

According to the invention, there is provided an oro-nasal mask moulded from flexible material such as a natural or synthetic rubber material wherein the mask

- 2 has an inside surface coated with a material to dampen any vibrations created during breathing in the mask or hoses connected thereto and thereby suppress any "noise" and interference generated thereby which could be sensed by a microphone when mounted therein.

s Preferably the damping material is substantially softer than the material from which the mask is moulded. The damping material can extend over the whole of the interior of the mask or alternatively, it can be provided only in the most strategic locations within the mask.

Preferably the damping material is polymer based natural or synthetic rubber which can be bonded to the interior of the mask or fixed/restraint system.

A preferred embodiment of the invention will now be described, by way of 15 example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic view showing an oro-nasal mask in position on a wearer's face; and Figure 2 is a cross section through the oro-nasal mask of the invention shown in 20 Figure 1.

Referring to the drawings there is shown in Figure 1 a respirator comprising a rigid outer shell 1 moulded from a rigid plastics material. The rigid shell I incorporates a transparent window 2 to allow the wearer to see out. A flexible 2s hood 3 is attached to the rigid shell 1 in known manner.

An oro-nasal mask 4 moulded from a flexible material such as a natural or synthetic rubber is attached at 1A to the inside face of the rigid outer shell 1.

The mask 4 has a peripheral edge 5 which makes a seal with the wearer's face. A do microphone 6 is mounted in the rigid shell I and protrudes through into the interior of the oro-nasal mask 4. An inlet hose 7 supplies breathable gas to the

- 3 interior of the oro-nasal mask and exhalate is expelled therefrom via an outlet hose (not shown).

It can be seen from the arrangement shown in Figures 1 and 2 of the drawings s that the microphone 6 is mounted not only in the rigid outer shell 1 but also in the oro-nasal mask 5. As a result, when the wearer inhales breathable gas from a gas supply (not shown) via the inlet hose 7, which tends to transmit noise from the gas supply or from outside noise. The same happens when the wearer breathes out via the outlet hose (not shown). The vibrations are picked up by lo the microphone 6 thereby creating interference which can impede the wearer's ability to communicate with other people through the microphone 6.

In order to reduce these interfering vibrations, it can be seen from Figure 2 that the interior surface of the oro-nasal mask 4 is coated with a damping material 8 Is which is much softer than the material from which the oro-nasal mask 4 is moulded. The materials currently used to mould the oro-nasal mask are much too hard to damp the vibrations which is why the additional soft damping coating 8 is added in accordance with the invention. The coating 8 can be applied to the whole of the interior surface of the oro-nasal mask 4 as illustrated 20 or alternatively can be strategically localised to cover only part of the interior of the mask e. g. the area around the microphone 6.

The preferred material for the coating 8 is polymer based natural or synthetic rubber or polyurethane, and can have a Shore hardness value in the range of 5 2s 50, but more preferably in the range of 15 - 30. The coating material 8 is preferably applied to the interior of the oro-nasal mask 4 by a bonding process or by known mechanical fixings.

Claims

- 4 Claims

1. An oro-nasal mask moulded from flexible material wherein the mask has an inside surface coated with a damping material to dampen any vibrations s created in the mask or hoses connected thereto during breathing and thereby suppress "noise" and interference generated during breathing which could be sensed by a microphone when mounted therein.

2. A mask as claimed in claim 1 wherein the damping material is substantially lo softer than the material from which the mask is moulded.

3. A mask as claimed in claim 1 or claim 2 wherein substantially the whole of the interior of the mask is coated with said damping material.

Is

4. A mask as claimed in claim 1 or claim 2 wherein only the part of the interior surface of the mask is coated with the damping material.

5. A mask as claimed in any preceding claim wherein the damping material is bonded on or mechanically fixed to the interior surface of the mask by a twin ^?0 shot moulding process.

6. A mask as claimed in any preceding claim wherein the damping material is synthetic polymer.

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7. mask as claimed in any preceding claim wherein the damping material has a Shore hardness value in the range of 5 - 50

8. A mask as claimed in any of claims 1 - 6 wherein the damping material has a Shore hardness value in the range of 15 - 30.