WO2014094008A2

WO2014094008A2 - Ear protection device

Info

Publication number: WO2014094008A2
Application number: PCT/AT2013/000202
Authority: WO
Inventors: Marko POGLITSCH
Original assignee: Poglitsch Marko
Priority date: 2012-12-19
Filing date: 2013-12-18
Publication date: 2014-06-26
Also published as: WO2014094008A3

Abstract

The present invention provides a device for protecting the ear canal and/or the eardrum of a user from physical contact with the ambient liquid medium when submerging in said medium. The device comprises (a) an earpiece being sized and dimensioned for tightly fitting the outer ear canal of the user, said earpiece being formed with a channel (8) having an inner opening (7) and an outer opening (6), said inner opening facing the eardrum (3) of the user and said outer opening facing the outside wherein in the space between the inner opening (7) and the ear drum (3), the volume of a permanent void (V_PV) is defined; and (b) an external open void being tightly fitted to said earpiece, wherein the ambient liquid medium enters said external open void through one or more outer openings (10), wherein at least a part of the inner surface (12) of said external open void is in direct contact with the ambient liquid medium.

Description

EAR PROTECTION DEVICE

FIELD OF THE INVENTION

This invention relates to underwater diving equipment that keep harmful foreign objects from contacting the ear canal and ear drum of a user when he or she is positioned at or below the surface of fresh water saltwater or any other liquid medium that is likely transport unwanted foreign matter into an ear. The present invention is reusable and provides protection of a user's ear from barotraumas and infection when the user is subjected to pressure increases up to 7-fold compared to surface ambient pressure. This makes the present invention ideal for use by those engaging in surface and subsurface marine construction and maintenance as well as use by sport divers. Commercial divers pile drivers hull scrapers and others often work in shallow water without any type of ear protection against water or fluid carried infection causing contaminants even though their work environment repeatedly places their ear drums and ear canals at risk for exposure to unhealthy substances such as mud barnacles oil hydraulic fluid creosote organic materials plant and animal life bacteria and other debris. Sport divers also place themselves at risk for ear disorders every time they dive and snorkel without ear protection in water that contains infection causing debris and bacteria an occurrence that appears to be increasing concern in recreational waters.

The present invention more particularly relates to devices for prevention of ear infections without interfering with the equalization of pressure between the diver's middle and outer ear and for preventing the outer ear from the entry of water and while diving.

BACKGROUND OF THE INVENTION

The human ear is made up of three sections commonly designated the outer ear the middle ear and the inner ear (Figure 1). The outer ear (1) includes the portion of the ear from the eardrum (3) outward to the ear opening (5), which is typically around 25 mm long (ECL, Ear Canal Length) in adult humans, with an average diameter of 7 mm (ECT), Ear Canal Diameter). The inner ear includes the cochlea and the three semi circular canals (not shown). The middle ear (2) is that portion of the ear between the eardrum and the inner ear. The middle ear is connected to the mouth cavity not shown through the eustachian tube (4) whose main function is to equalize the pressure between the middle ear and the mouth cavity, which is typically at the ambient pressure. Thus under normal conditions whenever the ambient pressure changes, the pressure in the outer ear and the pressure in the mouth cavity change as there do not exist physical barriers preventing pressure equilibration.

The rise in pressure in the mouth cavity brings about a concomitant rise in the middle ear by an equalizing flow of air from the mouth cavity to the middle ear through the eustachian tubes and therefore prevents a pressure difference across the eardrum, which causes discomfort and pain and might result in the rupture of the eardrum. The pressure equalization is particularly important for divers since the ambient pressure changes dramatically and rapidly as the diver lowers himself beneath the water surface or rises toward the water surface.

Equalization is impossible if the transmission of pressure between the outer surface of the eardrum and the ambient or between the inner surface of the eardrum and the mouth cavity is blocked. The transmission of pressure might be blocked by objects including earplugs or by secretions or swelling of surrounding tissues, which usually occur as a result of ear infections. Different pressures in the outer ear and the middle ear lead to a physical irritation of the eardrum causing symptoms that vary from discomfort to great pain and could in some cases lead to the rupture of the eardrum. A rupture of the eardrum is especially dangerous when descending, as water can enter the middle and the ear possibly leading to a loss of orientation and severe vertigo.

When descending, the ambient air being present in the outer ear at the surface (Example 1, Condition 1) is compressed as the ambient pressure increases strongly with depth leading to a pressure of about 5000 mbar (approximately 5 atmospheres) at a depth of 40 meters (Example 1 , Condition 2). At a depth of 40 meters (Figure 2), the air in the outer ear (RA, Residual Air) is already compressed to one fifth of the initial volume meaning that a significant amount of water (W, Water) (four fifth of the outer ear volume) entered the outer ear. The physical properties of the ear canal also provide that the water distributes evenly inside the ear and gets in contact with the eardrum, which can also occur at depths below 40 meters if the head is turned to one side and the bubble of residual air (RA) escapes the ear during water enters. The entry of water into the outer ear during diving is considered to be the major cause of diving associated ear problems being associated with discomfort, pain and ear infections. Under normal conditions, the outer ear is humidified and protected from infections by secreted earwax. This layer of earwax is essential to keep the sensitive skin inside the outer ear smooth and intact, allowing it to act as an efficient barrier against microorganisms possibly causing painful infections that might be associated with a block of ambient pressure transmission to the eardrum. Especially during repetitive dives, this protective layer is significantly disturbed or even removed, which resulted in attempts to reconstitute this protective layer with artificial substances being administered as eardrops suggested for the prevention of ear infection with limited success.

Especially diving activities in tropical regions are associated with an increased risk of ear infections. After diving, residual water usually remains in the outer ear leading to inorganic and organic remnants upon drying. Tropical seawater usually contains a significant amount of salt, bacteria and little animals (plankton), which remain in the outer ear when residual water dries after diving. These remnants represent a source of nutrients for microbial growth and together with their associated micro-flora they establish an infectious environment significantly increasing the risk of ear infections. Furthermore, repetitive cycles of wet and dry periods as well as the presence of salt in seawater lead to the physical irritation of the skin in the outer ear that are thought to cause skin erosions enabling infectious bacteria to cross the skin barrier and enter the tissue. Consequently several approaches were initiated to prevent water from entering the ear while permitting a functional process of equalization.

US Pat No 4,896,380 discloses a facemask, which is equipped with a pair of tubes. Each tube features an earplug at its far end. Each of the earplugs can be plugged into the ear canal and air from the facemask is able to reach the outer ear through the tube in order to equalize the pressure across the eardrum. A disadvantage of such a system is that the air pressure from the mask is transferred directly to the outer ear. The inside of a dive mask is divided from the surrounding water by physical barriers, which do not allow sufficient equalization automatically. During descending, the mask is pushed toward the face of the user and the air inside the mask is compressed due to increasing water pressure. It is necessary to equalize a diving mask during descending by inflating air through the nose actively in order to avoid a pressure difference between the mask and the exterior. According to US Pat No 4,896,380 the pressure difference between mask and exterior could be also present between outer and middle ear, representing a pressure difference across the eardrum leading to discomfort, pain and even discomfort as a consequence of the rupture of the eardrum of the user. US Pat No 2,488,235 also discloses an underwater facemask equipped with a pair of tubes. Each tube communicates at its far end with a substantially semi spherical ear cup which covers the user's ear. The ear cup is tightly fitted to the head of the user. The pressure inside the ear cups is equal to the pressure inside the mask leading to the similar problems and risks regarding possible pressure differences across the eardrum described for US Pat No 4,896,380.

US Pat No 5,483,975 teaches a device for facilitating the equalization of pressure across the eardrum of a user which typically includes a facemask configured to fit over at least the eyes and nose of the user. The device further includes a strap for securing the facemask to the face of the user. The strap when secured to the head of the user defines a single air space which includes ear portions overlying the user's ears and a connecting portion overlying the sides and back of the user's head and connecting the ear portions. Finally the device includes a tube for supplying air to the air space. One end of the tube is connected to the air space while the other end of the tube is connected to a source of pressurized air such as the facemask the air supply controller or the air supply mouthpiece. A disadvantage of such a device is that the strap is traditionally used for tightly securing the mask to the user's face such that it becomes water impermeable. Such device requires also adjustments of the ear portions such that they fit the position of the ears of a specific user. A mechanism for adjusting the position of the ear portions and for further tightly securing the mask to the users face requires both front and rear adjustments However due to the function of the strap as a single air space providing a rear adjustment is not feasible.

The above described prior art devices do solve some of the problems associated with diving however they call for replacing existing diving masks.

Us Pat No 5,865,183 suggests a solution for the problem described above, which separates the ear compartment used in the previously described devices from the mask piece. The ear compartment is constituted by an inflatable bag being in fluid communication with the exterior and is tightly fitted to an earplug. The inflatable bag serves as an air reservoir that feeds air into the outer ear through a hole in the earplug during diving and therefore avoids the entrance of water into the outer ear. The disadvantage of this device is that it is essential to fill the inflatable bag with sufficient air before diving. As there is no physical barrier between the inflatable and the outer ear of the user, air might escape the filled bag during positioning of the earplugs. This could particularly happen if the inflatable bags are attached to the straps, which are used to position the mask of the user as the mask has to be positioned before inserting the earplugs. If the inflatable bags would not be properly filled with air before diving, this would cause a fail in fluid communication and therefore prevents proper equalization. Under these conditions, the inflatable bag would loose its equalizing function completely, while blocking the outer ear canal resulting to a threatening pressure difference across the eardrum.

US Pat No 4,406,282 teaches an earplug for use underwater which includes a tubular vessel of soft flexible material adapted for insertion into the ear canal. A disadvantage of such a device concerns the difficulty to insert the tubular vessel of soft flexible material into the ear canal. Additional disadvantage concerns the limited change in pressure, which may be achieved in the outer ear using such a device.

US Pat No 7,185,655B suggests the use of an earplug with a flexible protrusion that extends into the outer part of the ear canal therefore allowing equilibration during diving. However, the protrusion might be easily blocked from extending into the ear canal by sticky earwax again leading to discomfort due to pressure differences across the eardrum. Furthermore, the residual air volume inside the ear canal is just 20% at a depth of 40m, which would require a very deep entry of the protrusion into the ear of the user again causing discomfort.

Although some of the inventions described above note that it is beneficial to decrease the rate of pressure change in the outer ear to make equalization more comfortable, there is a risk of harmful pressure differences across the eardrum associated with such strategies of ear protection, as the pressure in the outer ear is usually lower than the pressure in the middle ear, which is equal to ambient pressure via the eustachian tube. Reviewing the inventions summarized above, it becomes obvious that there is a strong need for an efficient way of protecting water from entering the ear of a diver while still transducing the ambient pressure to the eardrum without providing physical barriers changing this pressure significantly.

Many inventions in the field of diving try to prevent water from entering the ear canal by means like covering the ears of a user with cups that are vented during diving with the help of an air supply tube attached to the mask or the regulator of a diver. Another invention suggests the connection of the diving mask to the ears directly with an earpiece. Such devices represent risks in regard to pressure conditions that might rapidly change due to variations in the air supply. In contrast, there are also inventions suggesting the use of a closed inflatable bag in combination with an earpiece being tightly connected to the ear canal, which basically might work. However, there is a significant risk of misuse, as the inflatable bag has to be inflated before diving unless causing eardrum damage. Furthermore, all these devices are attached or tightly associated with the diving mask, which means that taking off the diving mask, which is necessary under certain conditions like diving courses, results in a fail of the ear protection as the earplugs have to be removed simultaneously. The present invention provides a device overcoming these disadvantages.

BRIEF DESCIPTION OF THE INVENTION

The present invention provides a device for protecting the ear canal and/or the eardrum of a user from physical contact with the ambient liquid medium when submerging in said medium. The device comprises (a) an earpiece being sized and dimensioned for tightly fitting the outer ear canal of the user, said earpiece being formed with a channel (8) having an inner opening (7) and an outer opening (6), said inner opening facing the eardrum (3) of the user and said outer opening facing the outside wherein in the space between the inner opening (7) and the ear drum (3), the volume of a permanent void (Vpv) is defined; and (b) an external open void being tightly fitted to said earpiece, wherein the ambient liquid medium enters said external open void through one or more outer openings (10), wherein at least a part of the inner surface (12) of said external open void is in direct contact with the ambient liquid medium.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1: Schematic representation of the human ear on the surface at sea level (1000 mbar) showing the outer ear, the middle ear, the eardrum and the Eustachian tube.

Figure 2: Schematic representation of the human ear under water at a depth of 40 meters showing the outer ear, the middle ear, the eardrum and the Eustachian tube. Water (W) enters the ear canal due to the compression of the air initially present to a much lover volume of residual air (RA). Figure 3: Schematic representation of the earpiece being comprised of an outer opening (6), an inner opening (7) and a channel (8) spanning from the inner to the outer opening of the earpiece.

Figure 4: Schematic representation of the tube used for constructing the device with D being the inner diameter of the tube.

Figure 5: Schematic representation of the earpiece connected to the tube via an L-shaped connection piece (13) with tight seals (14) at the interfaces to the adjacent tubes.

Figure 6: Schematic representation showing the fit of the device into the ear canal of the user with (15) being the contact zone between the device and the ear canal skin that might be sealed with the help of a sealing mass. Vpv indicates the volume of the permanent void formed between the earpiece of the device and the eardrum of the user.

Figure 7: Schematic representation of the device illustrating the tube length and tight fit to the earpiece.

Figure 8: Schematic representation of a functional prototype of the device during a dive showing the water plug present in a tube shaped external open void forming a connected compartment of compressed air spanning parts of the device and the permanent void between the earpiece of the device and the eardrum. During a dive, water freely enters the tube according to the ambient pressure.

Figure 9: Schematic representation of a functional prototype with an external open void consisting of multiple parallel and converging tubes forming a more complex external open void. The tubes converge into a single compartment or tube or junction piece (24) and two earpieces are attached to this compartment. During a dive, water freely enters the tubes as a result of increasing ambient pressure while the air inside the device and the ear canal is compressed.

Figure 10: Schematic representation of a functional prototype, which consists of two separate external open voids each being attached to one ear of the user via an earpiece. Each external open void consists of multiple parallel and converging tubes forming a more complex external open void. During a dive, water freely enters the tubes as a result of increasing ambient pressure while the air inside the device and the ear canal is compressed.

Figure 11: Schematic representation of a functional prototype of the device suitable for communication and/or music entertainment purposes. Speaker units (SU) and electronic devices (ED) are integrated for communication or music entertainment purposes and are shown in the representations at one possible integration site. The figure shows a sound and/or signal transmission suitable version of the device shown in Figure 9.

Figure 12: The figure shows a schematic representation of a sound and/or signal transmission suitable version of the device based on the construction form shown in shown in Figure 10. ED: Electronic device; SU: Speaker unit

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a device for protecting the ear canal and/or the eardrum of a user from physical contact with the ambient liquid medium when submerging in said medium, comprising

(a) an earpiece being sized and dimensioned for tightly fitting the outer ear canal of the user, said earpiece being formed with a channel (8) having an inner opening (7) and an outer opening (6), said inner opening facing the eardrum (3) of the user and said outer opening facing the outside wherein in the space between the inner opening (7) and the ear drum (3), the volume of a permanent void (VPV) is defined; and

(b) an external open void being tightly fitted to said earpiece, wherein the ambient liquid medium enters said external open void through one or more outer openings (10), wherein at least a part of the inner surface (12) of said external open void is in direct contact with the ambient liquid medium.

In contrast to previous inventions, this invention provides no physical barrier between the ambient liquid medium and the eardrum. The device serves as a reservoir of air, which is barrier free and thus, in direct communication with the ambient fluid. Thereby, water is prevented from entering the ear when the air inside the ear is compressed due to an increase in ambient pressure.

In an embodiment of the present invention the ambient medium can enter said external open void through said one or more outer openings (10) allowing the flow of liquids and gases in and/or through said external open void, being tightly fitted to said earpiece, wherein at least a part of the inner surface (12) of said external open void is in direct contact with the ambient liquid medium entering the external open void through the one or more outer openings (10). The present invention comprises an earpiece (Figure 3, 16), which is tightly fitted to the outer ear of the user so that water is prevented from entering the ear between the skin of the ear canal and the outer surface of the earpiece (9). The earpiece possesses an outer opening (6) facing the exterior and an inner opening (7) facing the eardrum. The inner and the outer opening are connected via a channel (8), which is easily permeable for air.

There are many materials suitable for providing the properties required for the present invention. Desired properties include plasticity, stability and durability with a clear focus on achieving a tight fit and prevent water from entering the ear canal beside the earplug. In an embodiment of the present invention said earpiece is made entirely or in part of a material selected from the group consisting of plastic, rubber, silicon, synthetic polymer, natural polymer, ceramics, metals and metal alloys. Additional effort might be required to completely prevent ambient liquid medium from entering the ear canal via the interface (15) between said earpiece and the ear canal. In another embodiment of the present invention a tight fit of said earpiece to the outer ear is achieved by applying a sealing mass onto said earpiece. The sealing mass used might be a wax, gel, or grease or any other kind of sealing mass, which is non-toxic when applied to the skin. The outer opening of said earpiece is tightly connected a void. In another embodiment of the present invention said external open void is of tubular geometry either entirely or in part. The tube (Figure 4) might be of any thinkable cross- sectional geometry including but not limited to circular, elliptic, triangular, square shaped or polygonal.

In another embodiment of the present invention the parts of the inner surface (12) of the external open void being in direct contact with the ambient liquid medium are not a capillary system. According to the present invention, the parts of the external open void being in direct contact with the ambient liquid medium do not support capillary motion of the ambient liquid medium in at least a part of the external open void. Capillary action or capillary motion is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity and/or pressure. If the diameter of a tube or narrow space is sufficiently small, then the combination of surface tension of a liquid medium and adhesive forces between the liquid and the container act to move the liquid against gravity and other external forces. Therefore, material properties of the container (e.g. hydrophobicity, distance between container walls, surface structures...) in combination with the properties of the ambient liquid medium (e.g. salt water, fresh water, water containing sediments) define the capillary potential of a selected combination. Capillary motion in at least a part of the external open void would result in capillary movement of ambient liquid medium towards the direction of the eardrum, leading to difference between ambient pressure and the pressure acting on the eardrum of the user, that might cause pain and eardrum damages.

Ref . : http://en.wikipedia.org/wiki/Capillary action

According to the present invention a capillary system is any combination of an ambient liquid medium with any part of the external open void being in direct contact with said ambient liquid medium via its inner surface, resulting in a capillary movement of said liquid ambient medium in said part of the external open void exceeding 2mm, 4mm, 6mm, 8mm, 10mm, 20mm or 40mm.

The connection between the earpiece and the external open void might be established by any means, included but not limited to gluing, melting, sticking, plugging, fusing, inserting linear and/or L-shaped (13) tube connection pieces, provided that the connection remains freely permeable for air and provided that water is prevented from entering the void or the channel at the site of connection (14). The void is freely accessible for the ambient medium via one or more outer openings (10). The void with one or more outer openings ("external open void") is freely accessible by water or other ambient liquid media. In another embodiment of the present invention said external open void is made entirely or in part of a material selected from the group consisting of plastic, rubber, silicon, synthetic polymer, natural polymer, ceramics, metals and metal alloys. In another embodiment of the present invention the inner surface (12) of said external open void is water repelling and/or dirt repelling. In another embodiment of the present invention the inner surface (12) of said external open void is impregnated with substances possessing anti-microbial and/or dirt repelling and/or water repelling activity. This helps to avoid a contamination of the outer part of the device with bacteria. The present invention uses the ambient liquid medium as a direct mean of pressure transmission to the eardrum of the user. The ambient medium might be saltwater or freshwater containing variable amounts of various impurities and particles. The water including these impurities and particles will enter the device, which results in highly specified requirements regarding the material, which builds up said external open void. The void or tube wall (11) might be made of any material including plastics, artificial polymers, rubbers, silicon based polymers, metals, metal alloys and ceramics and might be built in any thinkable geometric shape. The inner surface of the external open void or tube (12) might be coated or impregnated with one or more further material layers, and/or nanostructures and/or substances providing certain desired physical properties to the inner surface of the external open void. Such properties might include hydrophobicity, antimicrobial activity and dirt-repelling function. Such layers might include PTFE (Polytetraflourethylen, Teflon) thin layers or metal (preferably copper and/or silver and/or titanium) containing impregnations.

An example for an anti-microbial impregnation can be found on:

http://www.oxititan.com/what-is-oxititan/oxititan-as-an-antimicrobial/

Another possibility known to prevent the adhesion of dirt to surfaces while increasing their hydrophobicity is to change the nanostructure of the surface and/or apply certain materials. The Lotus-Effect is a well-known water and dirt-repelling effect found on certain plant leaves. Ref.: http://en.wikipedia.org/wiki/Lotus effect

Some nanotechnologists have developed treatments, coatings, paints, roof tiles, fabrics and other surfaces that can stay dry and clean themselves in the same way as the lotus leaf. This can usually be achieved using special fluorochemical or silicone treatments on structured surfaces or with compositions containing micro-scale particulates. Super-hydrophobic coatings comprising Teflon microparticles have been used on medical diagnostic slides for over 30 years. It is possible to achieve such effects by using combinations of polyethylene glycol with glucose and sucrose (or any insoluble particulate) in conjunction with a hydrophobic substance.

Surprisingly it turned out that hydrophobicity of the inner surface of the external open void or tube used in the present invention is essential for the proper function of the invented device as the depth and therefore the ambient pressure decreases and increases during a dive meaning that water enters and exits the external open void. It turned out to be important that the water flows in and out through the one or more outer openings (10) of the external open void or tube in a controlled way meaning that no residual water drops remain inside the tube, independent of the orientation in three dimensional space the tube is positioned at the time of water entry and exit due to pressure change. In another embodiment of the present invention said flow of liquid ambient medium through and/or into said external open void occurs as a plug flow independent of the orientation of said external open void in the three-dimensional space. Said plug-flow is facilitated by using hydrophobic materials or coatings for building up the inner surface of said external open void. In another embodiment of the invention the ambient liquid medium entering said tube forms a convex meniscus at the interface to the gas phase (23), which is observed independent of the orientation of said tube in the three-dimensional space. The convex meniscus is an indicator for low adhesive forces between the inner surface of the tube and the liquid medium, reflecting the water repelling properties of the inner tube surface. Ref.:

http://www.tutorvista.conVcontent/physics/physics-iii/solids-and-fluids/shape-meniscus.php#

The device according to present invention has to be tightly fitted to the ear canal of the user (Figure 6) to avoid water fro entering the device through ways other than the outer opening (10) of said tube. This might also be achieved by applying a wax and/or other sealing masses onto the outer side of the earpiece (9) or into the ear canal prior the insertion of the earpiece. The Device should be positioned in the ear of the user in a way that the seal between earpiece and the ear canal (15) is impermeable to water and that a permanent void (PV) is defined between the plane of the inner opening of the earpiece and the ear drum, which volume is calculated by Equation 5 below.

In case of using a tubular external open void, the diameter of the tube (D) is preferably selected in a dimension that allows water to flow inside the tube in a plug flow, which is provided by the surface tension of water in combination with the appropriate hydrophobic properties of the tube wall. In one embodiment of the present invention, a silicon tube of a diameter of 3 mm was used to build one prototype and to perform initial experiments. In another embodiment of the present invention said tubular external open void has a diameter of 1 to 6 mm, preferably 2 to 4 mm, most preferably 3 mm. In another embodiment of the present invention said external open void has a cross-sectional area of 0.8 to 30 square millimetres, preferably 3 to 13 square millimetres most preferably 7 square millimetres. In another embodiment, the device is suitable for diving to a depth of up to 10, 20, 30 and/or 40 m.

The required length (TL) of the tube (Figure 7) and therefore its volume defines the capacity of the device to prevent water from entering the ear when ambient pressure changes under water. The higher the pressure ratio p₂/pi between depth (pi) and shallow (p₂) the longer the tube must be in order to provide enough volume at p₂ to compensate for the air compression in the outer ear (see Table 1). The theoretical volume of water entering the ear canal reflecting the air compression in the ear canal can be calculated based on average values for the diameter and length of the ear canal. Individual differences are common regarding the ear canal dimension, especially in case of children, which requires fitting the tube length to different ear canal dimensions.

According to the differences observed in ear canal architecture, in another embodiment of the present invention the volume between the one or more outer openings (10) of said external open void and the inner opening of the earpiece (7) is at least equal to the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3). Said embodiment might be used for diving to a depth of up to 10 m. In another embodiment of the present invention the volume between the one or more outer openings (10) of said external open void and the inner opening of the earpiece (7) is at least two-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3). Said embodiment might be used for diving to a depth of up to 20 m. In another embodiment of the present invention the volume between the one or more outer openings (10) of said external open void and the inner opening of the earpiece (7) is at least three-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3). Said embodiment might be used for diving to a depth of up to 30 m. In another embodiment of the present invention the volume between the one or more outer openings (10) of said external open void and the inner opening of the earpiece (7) is at least four-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3). Said embodiment might be used for diving to a depth of up to 40 m.

The different external open void or tube volumes and tube lengths that might me needed for alternative applications of the present invention can easily be determined by a person skilled in the art based on the guidance provided in the present invention. According to different requirements like diving depths or ear canal volumes, the device might require adaptions in the construction as described herein or as determined by the skilled person. In another embodiment of the present invention one ore more of said devices are attached to the body of the user via a carrier and/or a piece of equipment. As shown in Figure 8, the device can be constructed as a collar band combining two devices to protect both ears simultaneously from water entry. Alternatively, the device might be constructed as a hearing aid especially for shallower depths, were shorter tubes are required. Therefore, the external open void or tube might be stored in a water permeable case behind the ear of a user with a second shorter tube running from behind the ear to the opening of the ear canal, where the earpiece is inserted.

In another embodiment of the present invention the external open void is built up by two or more subunits being tightly connected to each other via tubes and/or adapter pieces. These subunits might be of any geometric shape. In another embodiment of the present invention the required volume of the external open void (Vov) might be achieved by using more than one tube being arranged in parallel building up the external open void (Figure 9, 10, 11, 12). Said tubes might converge in a junction piece (24) providing further attachment sites for tubes leading to one or more earpieces. All tubes are tightly connected to the junction piece whereas a watertight seal might be achieved by applying sealing mass before attaching the tubes. The use of two or more tubes converging in a single compartment and/or tube introduces a further degree of redundancy into the device, which can increase safety. The higher number of outer openings decreases the risk of occlusion of the outer opening during diving. The use of shorter tubes further allows a more compact design of the device. The parallel use of two or more tubes leads also to a decrease in the flow resistance for water through the device allowing the reduction of the tube diameter.

Alternatively, the device might be integrated into a dive, swim or surf hood or might be designed as two independent devices while one is attached to each ear of the user via any fixing mechanism. Integrating the device into a hood is a special advantage when diving in cold water. Most of the body heat is lost via the head, which makes it favorable to protect the head from cold water by wearing a hood. The device can be integrated in such a hood in a way that the outer opening of the device is in contact with the ambient fluid while the earpiece is worn below the hood. The modular composition of the device allows change individual modules like earpieces and connection tubes and would also allow switching to different tube lengths or materials if desired or necessary. In another embodiment of the present invention said external open void entirely or in part is used to transmit acoustic signals to the ear of the user. For that purpose, a certain module containing a speaker might be integrated into the device, which could be used for underwater communication if combined with a suitable speech converting and signal transmitting system. One or more speaker units (SU) and/or one or more electronic devices (ED) might be integrated into the device via any kind of connection piece (25) that allows the transmission of sound produced by the speaker into the external open void or tube (Figure 11 and 12). Preferably, speaker units are attached to any part of the external open void, which remains dry during diving and might be attached via a T- or Y- shaped tube connector (25) to the external open void near the ear of the user. Recording and transmitting speech and noses under water might be achieved with a throat- microphone in combination with a suitable electromagnetic or other underwater compatible transmission system.

Further Embodiments:

1. A device for protecting the ear canal and/or the eardrum of a user from physical contact with the ambient liquid medium when submerging in said medium, comprising

(a) an ear piece being sized and dimensioned for tightly fitting the outer ear canal of the user, said ear piece being formed with a channel (8) having an inner opening (7) and an outer opening (6), said inner opening facing the eardrum (3) of the user and said outer opening facing the outside wherein in the space between the inner opening (7) and the ear drum (3), the volume of a permanent void (V_PV) is defined; and

(b) a tube allowing the flow of liquids and gases through said tube, being tightly fitted to said ear peace via said outer opening (6), wherein said tube allows a rapid fluid communication between said permanent void and the ambient medium mediated by a flow of liquid ambient medium and/or gas through the tube, wherein at least a part of the inner surface of said tube (12) is in direct contact with the liquid ambient medium.

2. The device of embodiment 1, wherein said ear piece is made of a material selected from the group consisting of plastic, rubber, silicon, synthetic polymer, natural polymer, ceramics, metals and metal alloys.

3. The device of embodiment 1 or 2, wherein a tight fit of said earpiece to the outer ear is achieved by applying a sealing mass onto said earpiece.

4. The device of any of the preceding embodiments, wherein said tube is made entirely or in part of a material selected from the group consisting of plastic, rubber, silicon, synthetic polymer, natural polymer, ceramics, metals and metal alloys.

5. The device of any of the preceding embodiments, wherein the inner surface of said tube (12) is water and/or dirt repelling. The device of any of the preceding embodiments, wherein the inner surface of said tube (12) is impregnated with substances possessing anti-microbial activity. The device of any of the preceding embodiments, wherein the volume of the tube between the open end of the tube (10) and the inner opening of the earpiece (7) is at least equal to the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3). The device of any of the preceding embodiments, wherein the volume of the tube between the open end of the tube ( 10) and the inner opening of the earpiece (7) is at least two-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3). The device of any of the preceding embodiments, wherein the volume of the tube between the open end of the tube (10) and the inner opening of the earpiece (7) is at least three-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3). The device of any of the preceding embodiments, wherein the volume of the tube between the open end of the tube (10) and the inner opening of the earpiece (7) is at least four-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3). The device of any of the preceding embodiments, wherein the ambient liquid medium entering said tube forms a convex meniscus at the interface to the gas phase (23), which is observed independent of the orientation of said tube in the three-dimensional space. The device of any of the preceding embodiments, wherein one ore more of said devices are attached to a carrier that might be fixed to the equipment or body of a user. The device of any of the preceding embodiments, wherein said tube is built up by two or more subunits being tightly connected to each other via tubes and/or adapter pieces. 14. The device of any of the preceding embodiments, wherein said tube is used to transmit acoustic signals to the ear of the user.

15. The device of any of the preceding embodiments, wherein said tube has a diameter of 1 to 6 mm, preferably 2 to 4 mm, most preferably 3 mm.

Example 1: Air compression in the ear canal at a depth of 40 meters

The properties of gases can be described by following simplified equation: p*V = n*R*T (Equation 1)

Wherein p is the actual pressure of a gas, V is the volume, n is the amount of the gas in moles, T is the temperature in Kelvin and R is the gas constant. The volume of a certain amount of gas (n=T) is dependent on ambient pressure and temperature. When a certain amount of gas is subjected to different pressures (Condition 1 : Surface and Condition 2: 40 meters water depth) at a constant temperature (T1=T2=T), Equation 1 delivers one equation for each condition:

Condition 1 : pi*Vi = R*T

Condition 2: p₂*V₂ = R*T

or combined:

pi x Vi = p2 x V₂ (Equation 2)

The ambient pressure at sea level is around 1000 mbar (Condition 1 : Figure 1), slightly varying with the weather conditions. The pressure at 40 meters is calculated by adding the ambient pressure at the surface to the pressure applied by a water column of 40 meters, which is approximately 4000 mbar (without considering the salt content of seawater). Therefore the pressure at 40 meters depth is calculated to be 5000 mbar (Condition 2: Figure 2).

Equation 2 can be transformed to deliver the pressure ratio based volume compression factor Vi V₂ where Vi is the volume of the gas under pressure pi (Condition 1) and V₂ is the volume of the gas under pressure p₂ (Condition 2): V] V₂ = p₂/pi (Equation 3)

Therefore, the pressure based volume compression factor for the conditions given in Example 1 is:

Vi / V₂ = 5000 / 1000

or

V₂ = V, / 5

or

V₂ = 0.2*V,

Which means that the initial volume (Vi) was compressed to the volume V₂, which is 20% of Vi (Residual Air, RA). At greater depths, the water is usually colder, reaching temperatures as low as 4°C (277K). If the temperature at the surface is for example 30°C (303K), which occurs frequently especially in tropical regions the temperature can not be considered to be constant, which was assumed to get to Equation 2 above.

Calculation of the volume V₂ with the temperatures being Ti and T₂ for Example 1 delivers: V₂ = pi/p₂ * Vi * T₂/Ti (Equation 4)

V₂ = 1000/5000 * Vi * 277/303 V₂ = 0.2 * Vi * 0.91

Therefore, the compression factor caused on a certain amount of gas by a temperature difference of 26°K is 0.91. 1 other words, a temperature difference of 26°K leads to a further compression of 9% due to the lower temperature, meaning that the tube length would have to be adapted accordingly. However, in the practical setting, the device will be dimensioned to provide safety buffer, which might exceed 10% by far.

Example 2: Tube Length (TL) Calculation The total air volume that is compressed during a dive when wearing the device can be divided into two main compartments: The permanent void (PV), which is the space between the inner opening of the earpiece (7) and the eardrum (3) and the external open void (OV), which is the space between the inner opening of the eaipiece (7) and the one or more outer openings of the device (10). Dividing the total volume of the device by the volume of the permanent void (PV), defines the compression factor that can be compensated by this individual device. In addition to ambient pressure, the temperature affects the volume of a gas. As the temperature in the depth is usually lower than in shallow waters, the temperature difference between the surface and the depth must be considered when calculating the tube length, as a longer tube is required compared to the tube length calculation for isotherm conditions.

The ratio between the total air volume (Vov + Vpy) and the volume of the permanent void (V_PV) determines the maximal pressure ratio (p2/pl) and therefore diving depth down to which the ears of the user are protected from water entry. Based on a tubular architecture of the external open void, the required tube length for different diving depths can be easily calculated (see example). In addition to ambient pressure, the temperature affects the volume of a gas. As the temperature in the depth is usually lower than in shallow waters, the temperature difference between the surface and the depth can be considered when calculating the tube length, as a longer tube is required compared to the tube length calculation for isotherm conditions.

The intermediate length and diameter of an adult ear canal is 25 mm and 7 mm respectively (Wikipedia: http://en.wikipedia.org/wiki/Ear_canal). When assuming a tubular architecture of the ear canal and assuming that the protrusion of the earpiece into the outer ear is 10 mm, the volume of the defined permanent void (Vpy) calculates as follows:

Vpy = r²*Pi*Lp_V (Equation 5)

While Lpv = 25 - 10 = 15 mm

Therefore, the Vpv calculates to V_PV = 0.577 ml

Therefore, a dive from the surface to 40 meters depth assuming a constant temperature would mean that this volume of air being present in the ear canal on the surface, would be compressed to 20%, which would be 0.1 15 ml (see Figure 1 and 2). The difference between the two volume values accounts for 0.462 ml, which represents the amount of water that would enter the ear canal without protection. Therefore, it is required that 0.462 ml of compressed air (at 40 meters / 5000 mbar) should be provided by the invention to keep the ear dry. Calculating back to surface ambient pressure gives the required reservoir volume of 2.309 ml at 1000 mbar ambient pressure (Sea level). This volume corresponds to a tube length of 327 mm (r = 1.5mm). In case that the temperature at the surface (Tl) and the temperature of the water (T2) are different, a correction factor for the tube length might be applied.

Vpv Depth p-Ratio Minimal Tube Minimal Tube Length [mm]

[mm3] fm] [p2/pl] Volume |mni3| (for D = 3 mm)

577 10 2 577 82

577 20 3 1 155 163

577 30 4 1732 245

577 40 5 2309 327

577 50 6 2886 408

577 60 7 3464 490

Table 1: Calculation of Minimal Tube Length (TL) (3 mm diameter tube)

Table 1 shows the correlation between the pressure ratio (p₂/pi) and the minimal tube volume required for diving to the indicated depth at a certain volume for the permanent void (Vpy = 577 mm3). Based on the minimal tube volume, the length of the tube is calculated for an inner diameter of the tube of 3 mm. The indicated length of the tube is associated with a maximal pressure range in which the device prevents water from entering the ear. However, a device suitable for the use across a pressure ratio of 7 can of course be used for shallower dives including snorkeling, which is usually done between sea level and a depth of 10 meters.

The length of the required tubes is considerably high, as a volume up to 3.5 ml of air needs to find space in the tube before diving down up to 60 meters starting at sea level. The diameter of the tube is limited by the surface tension of the liquid medium and the properties of the inner surface of the tube. A plug flow has to be maintained in order to avoid the liquid medium from freely flowing around in the device. Instead, liquid movement is only desired in response to pressure changes, which can be achieved only by a proper combination of tube hydrophobicity, an aqueous fluid and an appropriate tube diameter. A schematic representation of a device prototype using a tube as the external open void is shown in Figure 8: The device is built up in different modules, which are tightly connected (14) to each other. The earpiece (16), which is made of silicone, rubber, wax or any other mass suitable for sealing the ear of a user, is connected to a connection tube (17) via an reshaped connection piece (13). The connection tube itself is again tightly fitted to an L-shaped connection piece, which is attached to a winded tube extension (19), which is attached to a piece of tissue suitable for attachment to the body of the user with the ears of the user being reachable by both earpieces of the device. In case of a collar (as shown in Figure 8) any kind of closing mechanism (21, 22) might be used to suit the device to the collar size (CS) of the user. Wearing the device around the neck represents a great advantage for the user, as the device does not interfere with mask straps or caps. The mask cannot only be easily removed above but also under water, which is necessary especially during diving courses. Removing the mask does not result in a failing of the ear protection.

When ambient pressure under water rises during a dive, ambient water enters the external open void through one or more outer openings (10) according to the compression of the air inside the device and inside the ear canal. The open end of the tube might be protected from entering particles by a piece of tissue or a grid, which does not block the flow of water or gas into or out of the tube. The higher the ambient pressure increases, the further the water plug (23) travels along the tube in the direction of the earpiece. A given tube length and diameter define a tube volume, which is the space between the outer opening (10) of the tube and the inner opening of the earpiece (7). The volume defined by the space between the one or more outer openings (10) and the eardrum (3) is the total volume of compressible air in the system at the surface, which can be determined for external open voids with any geometry. The pressure and volume compression calculations shown in Example 2 and Table 1 are applicable for external open voids of any geometry provided that the volume of the external open void and the volume of the permanent void can be determined or estimated.

Claims

(a) an earpiece being sized and dimensioned for tightly fitting the outer ear canal of the user, said earpiece being formed with a channel (8) having an inner opening (7) and an outer opening (6), said inner opening facing the eardrum (3) of the user and said outer opening facing the outside wherein in the space between the inner opening (7) and the ear drum (3), the volume of a permanent void (V ) is defined; and

2. The device of to claim 1, wherein the ambient medium can enter said external open void through said one or more outer openings (10) allowing the flow of liquids and gases in and/or through said external open void, being tightly fitted to said earpiece, wherein at least a part of the inner surface (12) of said external open void is in direct contact with the ambient liquid medium entering the external open void through the one or more outer openings (10).

3. The device of any of the preceding claims, wherein said earpiece is made entirely or in part of a material selected from the group consisting of plastic, rubber, silicon, synthetic polymer, natural polymer, ceramics, metals and metal alloys.

4. The device of any of the preceding claims, wherein a tight fit of said earpiece to the outer ear is achieved by applying a sealing mass onto said earpiece.

5. The device of any of the preceding claims, wherein said external open void is made entirely or in part of a material selected from the group consisting of plastic, rubber, silicon, synthetic polymer, natural polymer, ceramics, metals and metal alloys.

6. The device of any of the preceding claims, wherein the inner surface (12) of said external open void is water repelling and/or dirt repelling.

7. The device of any of the preceding claims, wherein the inner surface (12) of said external open void is impregnated with substances possessing anti-microbial and/or dirt repelling and/or water repelling activity.

8. The device of any of the preceding claims, wherein the volume between the one or more outer openings (10) of said external open void and the inner opening of the earpiece (7) is at least equal to the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3).

9. The device of any of the preceding claims, wherein the volume between the one or more outer openings (10) of said external open void and the inner opening of the earpiece (7) is at least two-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3).

10. The device of any of the preceding claims, wherein the volume between the one or more outer openings (10) of said external open void and the inner opening of the earpiece (7) is at least three-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3).

11. The device of any of the preceding claims, wherein the volume between the one or more outer openings (10) of said external open void and the inner opening of the earpiece (7) is at least four-fold the volume of the permanent void between the inner opening of the earpiece (7) and the eardrum (3).

12. The device of any of the preceding claims, wherein said external open void is of tubular geometry either entirely or in part.

13. The device of any of the preceding claims, wherein the parts of the inner surface (12) of the external open void being in direct contact with the ambient liquid medium are not a capillary system.

14. The device of any of the preceding claims, wherein one ore more of said devices are attached to the body of the user via a carrier and/or a piece of equipment.

15. The device of any of the preceding claims, wherein said external open void is built up by two or more subunits being tightly connected to each other via tubes and/or adapter pieces.

16. The device of any of the preceding claims, wherein said external open void entirely or in part is used to transmit acoustic signals to the ear of the user.

17. The device of any of the preceding claims, wherein said external open void has a cross- sectional surface of 0.8 to 30 square millimetres, preferably 3 to 13 square millimetres most preferably 7 square millimetres.