WO2009090396A1

WO2009090396A1 - An ear protection device

Info

Publication number: WO2009090396A1
Application number: PCT/GB2009/000117
Authority: WO
Inventors: Ian Bailey; Robert Morse
Original assignee: Aerbuddies Ltd
Priority date: 2008-01-17
Filing date: 2009-01-16
Publication date: 2009-07-23
Also published as: GB2445480B; GB2445480A; GB0800893D0

Abstract

An ear protection device (10) comprises a body (12) arranged to be placed on, in or around an ear of a user. The body (12) has a formation arranged to close off at least part of the external auditory canal. The body (12) retains means (18) to increase locally the relative humidity within the external auditory canal. In another aspect of the invention, a ear protection device (10) comprises a body (12) which is arranged to be placed on, in or around an ear of a user with a formation arranged to close off at least part of the external auditory canal and including a source of water at or around ambient temperature (Fig.7).

Description

AN EAR PROTECTION DEVICE

The invention relates to an ear protection device intended to lessen the instance and/or ameliorate the effects of otic barotrauma, particularly although not exclusively, for use in pressurised aircraft.

Many passengers feel discomfort or pain in their ears when flying, particularly during the descent of the aircraft. The ear pain primarily results from a pressure difference between the outer and middle ear. Fig.l shows a schematic sectional view of the auditory system. When the ear is working normally, the Eustachian tube A which connects the middle ear B to the back of the nose (not shown), equalises the pressure between the middle ear B and the outer ear C. When the Eustachian tube A is blocked, for example through congestion due to a head cold, the pressure in the middle ear can differ to that in the outer ear. In pressurised aircraft, for example passenger aircraft, which cruise at altitudes typically from 30,000-35,000 feet, the cabin is pressurised to an equivalent of an altitude of 7,000-8,000 feet. Generally during take-off and the main part of the flight the pressure in the middle ear has an opportunity to equalise relative to the cabin pressure gradually. However, during descent if the Eustachian tube does not open fully the middle ear remains at a relatively low pressure relative to the pressure in the cabin which increases above the ambient pressure once the aeroplane has descended below (7,000-8,000 feet. Because aircraft tend to descent quite rapidly to make the best use of fuel, the change in cabin pressure once the aircraft has descended below 7,000 feet can be quite rapid, not allowing time for the middle ear pressure to equalise. In particular, if the Eustachian tube is blocked, a substantial pressure difference can exist across the tympanic membrane D (the ear drum) that separates the outer and middle ears. That pressure difference can lead to a painful retraction of the tympanic membrane, the pain generally being caused by rupture of the small blood vessels in the ear. The condition and symptoms are generally referred to as "otic barotrauma". In severe cases, the ear drum can be perforated possibly leading to permanent ear damage.

The anatomy of the Eustachian tube in infants and young children is different from adults. The Eustachian tubes runs more horizontally from the middle ear to the nose rather than the downward sloping tube that is seen in adults. It is believed that the horizontal course of the Eustachian tube can make infants and young children more prone to middle ear infections and therefore more prone to otic barotrauma. Research published in the report "Point Prevalence of Barotitus in Children and Adults after Flight and effect of Auto-Inflation" in the journal Aviation, Space and Environmental Medicine, 69 45-49 (1998) by Stangerup, Tjemstrom, Klokker, Harcourt and Stokholm found that otoscopic signs of ear damage from flying were found in 10% of adults and 22% of children. The report also found that the prevalence of negative middle ear pressure of more than lOhPa after landing was 20% in adults and 40% in children. A survey commissioned by Deafness Research UK in 2006 found that ear pain was the most commonly reported minor medical problem experienced while flying.

There are several recognised methods for treating the effects of otic barotrauma. The first, and most common, is called the Valsalva manoeuvre which involves pinching the nose whilst forcibly exhaling through the nostrils. This manoeuvre is effective in around half of adults but it is less effective in children and it can be difficult to explain how to perform that manoeuvre to children, especially when they are distressed. Also, the manoeuvre can cause damage to the tympanic membrane as the tympanic membrane snaps back as the pressure in the middle and outer ears is forcibly equalised.

The second method is to treat nasal congestion with a decongestant. There is published anecdotal evidence that such pharmaceuticals may relieve the instances and effects of otic barotraumas but not in all cases. In their report "Otic Barotrauma from Air Travel" J Laryngol. Otol., 119, 366 to 370 (2005) Mirza and Richardson reported that in three randomised control trials, one trial showed that oral pseudoephedrme decongestant reduced the pain of barotraumas whilst the second found that the oral pseudoephedrme did not decrease the pain of barotraumas in children and a third showed that a nasal decongestant taken 30 minutes before descent produced no statistically significant reduction in symptoms of barotraumas in adults with recurrent ear pain during air travel. Stangerup (1998) found that nearly three-quarters of adults and nearly 70% of children who are unable to equalise pressure using the Valsalva manoeuvre could improve or normalise their middle ear pressure by using nasal balloon inflation. One such nasal balloon is marketed as OTOVENT ™ and is intended to provide a controlled back pressure to open the Eustachian tube. However, as this involves inserting a tube into the nose and blowing up a balloon by blowing out through the nose and blocking one nostril, this is not a dignified procedure. Moreover, it is difficult to ask a distressed child to use the device in the circumstances of a flight and these products are not widely available.

There are also several earplugs on the market commonly referred to as pressure equalising earplugs that profess to reduce the instances of otic barotrauma. Generally the earplugs have a small hole through them that is blocked by a ceramic material of low porosity. The intention is that the earplug partially blocks the outer ear and enables a slower equalisation in pressure between the gap between the earplug and the cabin. On insertion of the earplug, the gap behind the earplug and the cabin will be the same pressure and on descent the pressure behind the gap equalises more slowly so that that pressure is more similar to the pressure in the middle ear than it would have been without the earplug. However, the report "Pressure - Equalising earplugs do not prevent barotrauma on descent from 8,000ft cabin altitude" in Aviation, Space and Environmental Medicine, 76, 1079 to 1082 (2005), Messrs Klokker, Vesterhauge and Jansen found that earplugs did not reduce the instances of barotrauma. However, various patents have been published relating to those devices including US Patent Nos.5467784, 5755234, 5819745, Australian Patent No.713512, New Zealand Patent No.319879, Russian Patent No.2177769 and Israel Patent No.124467.

Finally, one remedy promoted anecdotally by cabin attendants is to place a napkin in a paper cup and to soak the napkin with boiling water, then placing the cup over the ear. There does not appear to be any scientific literature relating to this method but anecdotally the method appears reasonably successful. All the written reports concern the use of a moistened napkin with boiling or very hot water. This may be due to the corollary from the traditional steam decongestant treatment for a head cold. One of the problems reported with the aforementioned method is that cabin staff are often unwilling to provide a passenger with boiling water intended to be placed near the ear due to the risk of burning and the possible consequent liability of a suit for damages.

The inventors of the present invention have surprisingly found that the above remedy is effective with cool water. It is postulated that the effects of otic barotrauma are heightened by stifihess of the tympanic membrane due to dehydration. In-flight cabin relative humidity falls on long distance high altitude flights to between 10-15% and can be low as 5%, indeed the air source is at less than 1% and the additional humidity comes from the occupants. This humidity is less than half that found in the worlds hot deserts and is a fifth of the level required for optimum comfort. The effect of in-flight dehydration on the skin, eyes and digestive system is well reported. However, it is believed that the tympanic membrane is particularly sensitive to humidity and that the drying of the tympanic membrane over the course of a long flight combined with rapid descent may explain why the effects of otic barotrauma appear to be more prevalent on landing than on take-off.

It is an object of the invention to provide an improved ear protection device.

According to a first aspect of the invention there is provided an ear protection device comprising a body which is arranged to be placed on, in or around an ear of a user, the body having a formation arranged to seal off the part of the external auditory canal between the tympanic membrane and the formation in a substantially airtight manner, the body retaining means to increase locally the relative humidity within the sealed off part of the external auditory canal.

In that way, the external surface of the tympanic membrane is exposed to an elevated level of humidity which reduces the drying effect of the low humidity cabin air and, it is believed, lessens the instances of or ameliorates the effects of otic barotrauma. In informal tests using an absorbent material and water at ambient temperature placed over the ear during descent, the effects of relief, particularly on young children were observed to be almost instantaneous. In an experiment using a tympanometer to measure the stiffness of the tympanic membrane, the middle ear pressure and the outer ear volume, it was observed that the activation of a dehumidifier in a sound proof booth reduced the compliance of the tympanic membrane and that the application of a cup with a moist paper towel applied to the ear produced a corresponding increase in the compliance of the tympanic membrane within minutes.

The means to increase locally relative humidity in the internal auditory canal (the humidity increasing means) preferably comprises means for exposing the external auditory canal to a source of hydrating fluid, such as water, most preferably at or around ambient temperature.

The source of hydrating fluid may be a water reservoir. The water reservoir may be arranged within the body. The water reservoir may be refillable.

The source of hydrating fluid may comprise an absorbent material soaked in water. For example a sponge, a textile or an open cell foamed material may be used. Again, the absorbent material may be refillable with water. Alternatively, the absorbent material may be received in a replaceable cartridge which is retained by the body in a replaceable fashion. In that way when the water in the absorbent material is used the cartridge can be replaced with a fresh cartridge of absorbent material. Still further, the source of hydrating fluid may be a gel or other such material.

The aforementioned reservoir or absorbent material may be closed off by means of removable film so as to retain the water in the reservoir or absorbent material until required for use. Alternatively, the reservoir or absorbent material may be closed off by means of a cap, most preferably effecting a water tight seal of the reservoir or absorbent material.

Still further, the source of hydrating fluid may comprise a spray mechanism or atomiser mechanism from a water reservoir. The body is preferably arranged to be placed in the ear of a user. In such a case, the body may comprise a relatively rigid main body and at least one relatively soft outwardly extending peripheral flange. Where the body is arranged to be placed in the ear, the humidity increasing means preferably comprises a formation in one end of the device which receives an absorbent material. The end may be closed off by a removable film or cap as described above, until desired to be used.

Alternatively, the body may be arranged to be placed on the ear and in such a case the body comprises the features described above where the body is arranged to be placed in the ear with the addition of a mounting formation arranged to extend around the outer ear so as to further secure the ear protection device on the ear.

In a still further embodiment the ear protection device has a body which is arranged to be placed around the ear of the user, hi such a case, the formation arranged to close off at least part of the external auditory canal comprises a formation which extends around the pinna of the ear so as to close off the whole outer ear. Alternatively, the formation may be arranged to abut against the surface of the pinna around the entrance to the external auditory canal.

The closing off of at least part of the external auditory canal may constitute providing an airtight seal of the external auditory canal. Alternatively, it may comprise providing a water tight seal. However, the term encompasses any restriction of air flow into and out of the external auditory canal that is sufficient to enable the relative humidity of that area to be increased by the humidity increasing means so as to have the aforementioned hydrating effect on the tympanic membrane.

According to another aspect of the invention there is provided an ear protection device comprising a body which is arranged to be placed on, in or around an ear of a user, the body having a formation arranged to close off at least part of the external auditory canal and the device including a source of water at or around ambient temperature, the source of water being closed off by means of a removable seal, film or cap. Ear protection devices in accordance with the invention will now be described in detail by way of example and with reference to the accompanying drawings, in which:-

Fig.1 is a schematic sectional view through a human auditory system,

Fig.2 is a schematic sectional view through an ear protection device according to the present invention,

Fig.3 is a view of the ear protection device of Fig.1 looking in the direction of arrow III-III,

Fig.4 is a schematic sectional view of the ear protection device of Figs.2 and 3 shown in place on an ear of the user,

Fig.5 is a schematic illustration of a set of headphones incorporatirig the device ofFigs.2-4,

Fig.6 is a side elevation of an alternative ear protection device in accordance with the invention.

Fig.7 is a sectional view taken through the ear protection device of Fig.6 in the direction of arrows VI-VL,

Fig.8 is a view similar to Fig.4 but shows the ear protection device of Figs.6 and 7.

In Figs.2-5 an around the ear protection device (EPD) 10 is shown.

The EPD 10 comprises a cup-like body 12 having a circular base 14 and a cylindrical side wall 16 extending away from the base 14. An absorbent material pad 18 is adhered, for example glued to the base 14 within the cylindrical side wall 16.

The end of the cylindrical side wall 16 that is spaced from the base 14 carries soft annular seal member 20. By soft we mean soft relative to the cup-like body 12.

The cup-like body 12 is closed off by means of a film material closure 22 which is adhered to the annular seal 20. It is preferred that the closure of the body by means of the film closure and the annular seal 20 is an hermetic seal. The absorbent pad 18 may be pre-soaked with water or alternatively the pad can have water applied to it once the film is removed. The film closure has two effects. Firstly, where the absorbent pad is pre-soaked it retains the moisture within the body and prevents the pad from drying out. Secondly, it keeps the interior of the cup including the absorbent pad in a sterile condition.

Fig.4 shows the EPD of Figs.2 and 3 in place over the ear of the user in schematic form.

Li Fig.4 it can be seen that the film closure 22 has been removed from the body 12 and the open end of the body 12 has been placed over the opening to the exterior auditory canal C. The annular seal 20 is pressed against the side of the head of the user or against the pinna part of the ear so as to close off the whole of the exterior auditory canal and it can be seen in Fig.4 that the absorbent pad 18 is exposed to the exterior auditory canal C. It can also be seen that the tympanic membrane D (or ear drum) is pressed inwardly towards the middle ear B. This illustrates the situation where the exterior cabin pressure is higher than the pressure in the middle ear cavity B. Consequently, the force of air pressure in the exterior auditory canal C will push the tympanic membrane D inwardly. By exposing the absorbent pad 18 to the exterior auditory canal C and closing off the canal by means of the seal 20, the relative humidity in the exterior auditory canal is elevated. That in turn can reduce the effects of dehydration on the tympanic membrane D and, correspondingly, reduce the instance of otic barotrauma or ameliorate its effects. In Fig.5 the EPD 10 forms part of a set of headphones 24. Those headphones may have additional functionality, for example they may have speakers for connection to media devices or the entertainment system of an aircraft. Moreover, the headphones may comprise a noise cancelling function.

Although we have shown the absorbent pad merely adhered to the base of the body 12, the pad may be installed in the cartridge which can be removably retained in the body, m particular, the cartridge may be clipped to the base or may be screwed to the base by means of a screw-threaded connection, hi an alternative embodiment of this arrangement the pad is retained in a cartridge which is screwed to the outside of the base of the body so that the cartridge can be removed and replenished with water or the pad replaced whilst still wearing the headphones.

In Figs.6 and 7 an in-the-ear EPD 110 is shown. The in-the-ear EPD 110 comprises an elongate body 112 formed in two parts best shown in Fig.7. In Fig.7 the body 112 comprises a handle part 114 made of a hard plastics material and an ear plug part 116.

The handle part is rigidly secured to the ear plug part so that the ear plug part 116 extends from one end of the handle part 114. The ear plug part 116 comprises an elongate shaft with a blind bore 118 formed longitudinally therein extending from the end opposite the handle part 114.

Extending radially outwardly from the shaft are three peripheral skirts 120, 122, 124 of soft plastics material. The first skirt 120 extends radially outwardly from the tip of the shaft 117 and then bends back towards the handle part 114. The second radially extending skirt 122 has a larger diameter than the first radially extending skirt.

The second radially extending skirt extends from a point spaced towards the handle

114 from the tip of the shaft 117. Finally, the third radially extending skirt has a larger diameter from the second radially extending skirt The third radially extending skirt extends from a point approximately midway along the shaft 117 from the handle

114 to the tip of the shaft. The blind bore 118 is closed off by means of a foil closure 126 which is glued to the tip of the shaft 117. The foil closure preferably hermetically seals of the bore 118. An absorbent foam cylinder 128 is located in the bore 118 and is soaked with water.

Fig.8 illustrates the in-the-ear ear protection device 110 of Figs.6 and 7 when inserted into the external auditory canal C an on ear of the user. The skirts 120, 122, 124 effect a closure by sealing off the external auditory canal C. The provision of three cascading progressing increasing diameters of skirts 120, 122, 124 accommodates varying ear canal sizes and also provides supplementary sealing to accommodate the taper of the ear canal.

Prior to insertion the film 126 is removed so as to expose the moistened absorbent cylinder 128 to atmosphere. The in-the-ear EPD 110 is then inserted into the external auditory canals leaving the part 114 of the body 112 exposed to facilitate ready removal of the EPD from the ear canal. By sealing off the ear canal from the outside atmosphere and by exposing the sealed off ear canal C to the moisture in the absorbent cylinder 128, the effects of dehydration of the tympanic membrane D are reduced which, it is believed, lessens the instance of otic barotrauma and ameliorates its effects.

The ear plug can be removed from the ear canal and the absorbent pad refreshed with clean water if required.

Alternatively, although not shown, the absorbent pad could be replaced by a cartridge containing an absorbent pad, which cartridge can be replaced with further cartridges when the moisture in one cartridge is exhausted. Although we describe a flanged insert, the insert can be as simple as a bung with an included reservoir or sponge.

Because of the near immediate effect of the application of a higher relative humidity to the external auditory canal up on ear pain, the devices shown in Figs.2-8 only need to be used as pain occurs, for example when the aircraft descends below the U equivalent cabin pressure altitude. In other words, once the cabin pressure is set to the ambient air pressure rather than the notional 8,000fl pressure for high altitude travel. In that way only a small amount of water is required to be aπranged in the absorbent pads for the ameliorating effect to last for the relevant period of descent.

Although the humidity increasing means has been described as an absorbent pad soaked with water, either of the devices could contain a water reservoir and some means for exposing the external auditory canal to that water reservoir. For example, a small spray or atomiser may be integrated into the entire device.

Also, the device shown in Figs.6-8 can be further secured on the ear by connection to an over-the-ear fixing. Still further, a securing to the ear can be in the manner of a clip such as is found in various hands-free mobile telephone communication devices.

Although the above focuses on barotraumas during descent, both above described embodiments are effective at treating air pain due to pressure to any point in a flight.

Both of the above devices can be made from or include a material incorporating an additive with antibacterial properties, such as that marketed under the brand MICROBAN ™. Also, both devices could be equipped with either active or passive acoustic control features. For example the around-the-ear device could be incorporated into a noise-cancelling headset. The in-the-ear device could include special features of shape to reduce noise passing down the ear canal.

Claims

1. An ear protection device comprising a body which is arranged to be placed on, in or around an ear of a user, the body having a formation arranged to seal off the part of the external auditory canal between the tympanic membrane and the formation in a substantially airtight manner, the body retaining means to increase locally the relative humidity within the sealed off part of the external auditory canal.

2. An ear protection device according to claim 1 in which the humidity increasing means comprises means for exposing the external canal to a source of water.

3. An ear protection device according to claim 2 in which the water in the source of water is at or around ambient temperature.

4. An ear protection device according to claim 2 or 3 in which the source of water is a water reservoir.

5. An ear protection device according to claim 4 in which the water reservoir is arranged within the body.

6. An ear protection device in accordance with claim 4 or 5 in which the water reservoir is refillable.

7. An ear protection device according to claim 2 in which the source of water comprises an absorbent material soaked in water.

8. An ear protection device accordirig to claim 7 in which the absorbent material comprises a sponge, textile or an open cell foamed material.

9. An ear protection device according to claim 7 or 8 in which the absorbent material can be replenished with water.

10. An ear protection device according to claim 7 or 8 in which the absorbent material is received in a replaceable cartridge, retained by the body in a replaceable fashion.

11. An ear protection device according to any of claims 2 to 10 in which the reservoir or absorbent material is closed off by means of a removable film so as to retain the water in the reservoir or absorbent material.

12. An ear protection device according to any of claims 2 to 10 in which the reservoir or absorbent material is closed off by means of a cap.

13. An ear protection device according to claim 12 in which the cap effects a watertight seal of the reservoir or absorbent material.

14. An ear protection device according to claim 2 in which the source of water comprises a spray mechanism or atomiser mechanism connected to a water reservoir.

15. An ear protection device according to any proceeding claim in which the body is arranged to be placed in the ear of a user.

16. An ear protection device according to claim 15 in which the body comprises a relatively rigid main body and at least one relatively soft outwardly extending peripheral flange.

17. An ear protection device according to claim 15 or 16 in which the humidity increasing means comprises a formation in one end of the device which receives an absorbent material.

18. An ear protection device according to claim 17 in which the end is closed off by a removable film or cap.

19. An ear protection device according to any of claims 1 to 14 in which the body is arranged to be placed on the ear, the body comprising a relatively rigid main body and at least one relatively soft outwardly extending peripheral flange together with a mounting formation arranged to extend around the outer ear so as to further secure the ear protection device on the ear.

20. An ear protection device according to any of claims 1 to 14 in which the ear protection device has a body which is arranged to be placed around the ear of the user.

21. An ear protection device according to claim 20 in which the formation arranged to close off at least part of the external auditory canal comprises a formation which extends around the pinna of the ear so as to close off the whole outer ear.

22. An ear protection device according to claim 20 in which the formation arranged to close off at least part of the external auditory canal is arranged to abut against the surface of the pinna around the ear.

23. An ear protection device comprising a body which is arranged to be placed on, in or around an ear of a user, the body having the formation arranged to close off at least part of the external auditory canal and the device including a source of water at or around ambient temperature, the source of water being closed off by means of a removable seal, film or cap.

24. An ear protection device according to claim 23, in which the source of water is an absorbent material soaked in water.

25. An ear protection device according to claim 24 Ln which the absorbent material comprises or is part of a replaceable cartridge.

26. An ear protection device according to any one of claims 23 to 25 in which the source of water is closed off by means of a removable cap and the cap is replaceable on the device.