WO2023017046A1

WO2023017046A1 - Devices, systems and methods for inducing temperature changes in the inner ear and/or labyrinth

Info

Publication number: WO2023017046A1
Application number: PCT/EP2022/072369
Authority: WO
Inventors: Dominik PÉUS
Original assignee: Peus Dominik
Priority date: 2021-08-10
Filing date: 2022-08-09
Publication date: 2023-02-16

Abstract

An ear device for inducing temperature changes in the inner ear and/or labyrinth of a subject is disclosed. The device comprises an at least partially flexible earcanal piece configured for at least partial insertion into an ear canal of the subject, the ear canal having a first turn, a second turn, an ear canal isthmus and an ear canal wall, the earcanal piece comprising a body and a contact portion, and a thermoelectrical element. The earcanal piece is configured such that, when inserted in the ear canal, a contact surface of the contact portion contacts a target portion of the ear canal wall distal of the ear canal isthmus and the second turn of the ear canal and proximal to the tympanic membrane for transferring thermal energy between the target portion and the ear device via the contact surface.

Description

Devices, systems and methods for inducing temperature changes in the inner ear and/or labyrinth

The present invention relates to devices, systems and methods for inducing temperature changes in the inner ear and/or labyrinth of a subject, e.g. a patient.

A variety of applications for inducing temperature changes in the ear canal of a patient are known. For example, US 2010/0198318 Al relates to cranial nerve stimulation, i.a. in order to treat migraine. For diagnosis and treatment of deficiencies related to balance disturbances it is known to induce temperature changes in the ear canal by introducing water that has an elevated or reduced temperature as compared to the natural body core temperature of a subject. However, known devices and techniques suffer from various drawbacks. For example, water-based temperature induction requires professional equipment that is usually expensive and large in size and thus not suitable for at home use by a patient. Known devices that resemble ear plugs are usually restricted to reaching only the outer part of the ear canal, i.e. those regions of the ear canal that are proximal of the second turn of the ear canal and therefore far away from the labyrinth. Two physical phenomena limit inducing temperature changes of the inner ear. First, the air in the ear canal distal of the ear plug in the outer part of the ear canal acts as a thermal insulator because of the low thermal conductivity of air (0,026 W/(m-K), and second the body of the living subject acts as a heat exchanger. The blood circulation transports the applicated heat or cooling and is quite effective in stabilizing the body core temperature of 37° C. A further difficulty is the S-shaped longitudinal course of the external ear canal with the narrowest anatomical width (isthmus) located approximately midway between the opening of the ear canal and the ear drum. The isthmus is often referred to as having the shape of an hourglass. As generally known in the art, the isthmus is the border or transition zone between the cartilage covered portion of the ear canal and the bony part of the ear canal.

It is therefore an object of the present invention to provide devices, systems and methods for inducing temperature changes in the inner ear and/or labyrinth with broad and flexible applications. In particular, the present invention overcomes at least some of the drawbacks of the prior art techniques.

According to a first aspect, the present invention relates to an ear device for inducing temperature changes in the inner ear and/or labyrinth of a subject, comprising an at least partially flexible earcanal piece configured for at least partial insertion into an ear canal of the subject. The ear canal has an ear canal wall. The ear canal may have a first turn, a second turn and an ear canal isthmus.- Additionally or alternatively the ear canal may have a bony part. The earcanal piece comprises a body and a contact portion, and a thermoelectrical element. The earcanal piece is configured such that, when inserted in the ear canal, a contact surface of the contact portion contacts a target portion of the ear canal wall distal of the ear canal isthmus and the second turn of the ear canal and proximal to the tympanic membrane for transferring thermal energy between the target portion and the ear device via the contact surface. Alternatively or additionally, the earcanal piece is configured such that, when inserted in the ear canal, the contact surface of the contact portion contacts the target portion of the ear canal wall in the bony part of the ear canal and proximal to the tympanic membrane for transferring thermal energy between the target portion and the ear device via the contact surface. The contact portion is expandable from a collapsed state to an expanded state, wherein in the collapsed state the contact portion, and particularly its width, is configured for passing the second turn and the isthmus, and wherein in the expanded state the contact portion, and particularly its width, is configured such that the contact surface contacts the target portion of the ear canal wall for transferring thermal energy between the target portion and the ear device via the contact surface. The thermoelectrical element is thermally connected to the contact surface and configured for regulating a temperature of the contact surface. Preferably, a ratio of the width of the contact portion in the expanded state to the width of the contact portion in the collapsed state is at least 1.2 to 2.

The subject may be a human subject or an animal subject.

The terms "proximal" and "distal" are used as generally known in the art, e.g. following the ear canal, "distal" is closer to the ear drum as compared to "proximal" and "proximal".

The thermoelectrical element may be an electronic device that is configured for heating and/or cooling. For example, the thermoelectrical element may be a Peltier element. As the thermoeletrical element is thermally connected to the contact surface and configured for regulating a temperature of the contact surface, the ear device is configured for inducing temperature changes in the inner ear and/or labyrinth of the subject via changing the temperature of the contact surface. The temperature of the contact surface is transmitted to the target portion of the ear canal wall and further to the bony and membranous labyrinth of the subject, particularly the lateral (also called horizontal), superior (also called anterior) and posterior semicircular canals, the canal ampullae, the utricle and saccule, the cochlea including, the organ of Corti, the stria vascularis, as well as the vestibular and cochlear (spiral) ganglions, the meatal, the labyrinthine, and mastoidal segment of the facial nerve and the vestibulocochlear nerve.

"Thermally connected" and/or "thermal connection" refers to a connection that facilitates transfer of a thermal energy as compared to a material that at least partially or entirely surrounds the thermal connection. For example, in a device having a metal wire surrounded by another material with a lower thermal conductivity than the metal wire, the metal wire provides a thermal connection. Particularly, a thermal connection may have a high or at least higher thermal conductivity than the surrounding material, as further detailed below.

As the earcanal piece is configured such that, when inserted in the ear canal, a contact surface of the contact portion contacts a target portion of the ear canal wall distal of the isthmus and/or in the bony part of the ear canal, the device and related systems and methods do not rely on the presence of water or other artificially introduced fluids in the ear canal. The transfer of thermal energy may occur in the absence of any artificially introduced fluid, particularly water.

The term "width" defines a lateral or transverse dimension that is relevant for passing a narrow portion of the ear canal. For example, the width may be the largest diameter of a cross section that is taken perpendicularly or at an angle to the longitudinal extension and/or axis of the device (e.g., perpendicularly or at an angle to the longitudinal extension of the device at the second turn and/or at the isthmus). The measurement of the width may be made along a largest diametrical extent of the earcanal piece and/or along a largest or smallest diametrical extent of the ear canal, depending on the context, i.e. depending on the limiting dimension. The longitudinal axis of the device may be defined as a curve extending from a proximal end (e.g. outer end) of the device that is to be located proximate the auricular concha to a second end (e.g. inner end) of the device that is to be located proximate the tympanic membrane. For example, when calculating the ratio of the width of the contact portion in the expanded state to the width of the contact portion in the collapsed state, one may take the largest diametrical extent in the expanded state divided by the largest diametrical extent in the collapsed state.

The width of the ear canal and of the isthmus may vary from subject to subject. Typical dimensions of the isthmus are: The average craniocaudal width is 9 mm (with a typical range of 5.4 mm - 16.5 mm across the population) and the average width in a transverse plane (i.e. the small diameter of the isthmus oval) is about 5.7 mm (with a typical range of 2.4 - 9.6 mm across the population). Typical dimensions of the ear canal aperture are: Typically, the aperture has a craniocaudal width of about 5.4-17.5 mm. The typical width in a body's transverse plane at the outer aperture is about 3.3-11.9 mm. The longitudinal ear canal lengths are between 23-28 mm on average for men whereas females have ear canal lengths of typically 21-26 mm.

The terms "collapsed state" and "expanded state" are to be seen relative to one another. This means that the collapsed state is collapsed as compared to the expanded state and the expanded state is expanded as compared to the collapsed state. Particularly, a width of the contact portion may be smaller in the collapsed state than in the expanded state. The expanded state may refer to a state that corresponds to maximal expansion or to an intermediate expansion, i.e. when further expansion would be possible for the device, e.g. if no restrictions (such as the ear canal) were present. The collapsed state may correspond to a maximally collapsed state or to an intermediate collapsed state, i.e. collapsing further may, as regards the device, be possible. In the expanded state the earcanal piece and particularly the contact portion may have a width in the transverse body plane of at least 5 to 6 mm, preferably 6 to 9 mm, at most 9 to 16.5 mm. In the collapsed state the earcanal piece and particularly the contact portion may have a width in the transversal body plane of at least 2 mm to 4 mm, preferably 4 to 6 mm, at most 10 mm. In the collapsed state the earcanal piece and particularly the contact portion may have a craniocaudal width of at least 4.1 mm to 5 mm, preferably 5 to 8 mm, at most 11 mm. Thus, it may be configured for passing the isthmus when in the collapsed state, and contact the target portion when in the expanded state.

The thermoelectrical element may be configured for providing a temperature of the contact surface above the subject's natural body core temperature. Preferably, the thermoelectrical element, as such, is configured to provide a temperature of about 44 °C to about 48 °C. Additionally or alternatively, the thermoelectrical element may be configured to provide a temperature of the contact surface below the subject's natural body core temperature, preferably a temperature of about 10 °C to about 30 °C. The subject's natural body core temperature may be 37°C.

As the contact surface contacts the ear canal at the target portion, a temperature of the ear canal at the target portion may be regulated via regulating the temperature of the contact surface.

The thermoelectrical element may be configured for providing a subject's body temperature at the target portion above the subject's natural body core temperature, preferably a temperature of about 44 °C to 48 °C, and/or a subject's body temperature at the target portion below the subject's natural body core temperature, preferably a temperature of about 10 °C to 30 °C. The subject's natural body core temperature may be 37°C.

The contact surface may have a high thermal conductivity, in particular a higher thermal conductivity than remaining portions of the ear device contacting the ear canal. "High thermal conductivity" may be defined as a thermal conductivity of at least 50 W/m*K, at least 100 W/mK, at least 200 W/m*K, or at least 300 W/m*K. For example, the contact surface may comprise one or a combination of the following materials: copper, gold, silver, aluminum, steel, nickel, titanium, different alloys, polymers with additives, or graphene for enhancing thermal conductivity. The remaining portions of the ear device contacting the ear canal may comprise one or a combination of the following materials: one or more types of polymers, e.g., polyethylene terephthalate (PET), polyether ether ketone (PEEK), thermoplastic elastomer (TPE) one or more types of silicones, ceramics, or graphene. Any combination of materials for the contact surface and the remaining portions of the ear device contacting the ear canal mentioned herein are contemplated, particularly the following combinations (the components "spring(s)" and "earcanal piece body core" will be defined further below): aluminum for contact surface, spring(s) and earcanal piece body core and TPE for the remaining portions; steel for the contact surface and spring(s), aluminum for the earcanal piece body core and silicone for the remaining portions; steel for the contact surface, nitinol for the spring(s) and flexible parts of the earcanal piece body core and PEEK for the remaining portions. The earcanal piece body core may be made of a combination of materials like in heat pipes which are two-phase heat dissipation devices. A high thermal conductivity of the contact surface as compared to the remaining portions of the ear device contacting the ear canal supports a targeted transport of thermal energy between the contact surface of the earcanal piece and the target portion of the ear canal. This may result in a reduction of unintended transport of thermal energy to and from other regions of the ear canal than the target portion and other parts of the ear device. This may not only increase the precision of heating or cooling of the target portion but may also result in a reduction of energy consumption for regulating the temperature, i.e. heating and/or cooling.

The target portion may comprise a posterior surface of the ear canal, preferably a posterior surface of the ear canal close to the tympanic membrane in the bony part of the ear canal. The ear canal piece of the present invention is configured to pass the narrowest portion of the ear canal (i.e., the isthmus) and subsequently contact the target portion in a region of the ear canal that is wider than the isthmus. This may be achieved in any possible way. Thereby, the target portion close to the tympanic membrane and distal of the isthmus may be reached.

The contact portion may be self-fitting. In particular, the contact portion may be configured to adjust one or more of its dimensions to the target portion of the ear canal. Generally, if something is self-fitting, it may be configured to adjust one or more of its dimensions. For example, if A is self-fitting to B, A may be configured to adjust one or more of its dimensions to B. The adjustment may be provided upon initiation by the subject and/or another person and/or a controller. Alternatively, the adjustment may occur in a fully automatic manner.

For example, the contact portion may comprise a shape memory material, such as Nitinol or a shape memory polymer, and adjust to the intended dimensions upon a temperature change. Such temperature change may be induced by the natural temperature of the ear canal and/or by providing a specific temperature at the contact surface via the thermoelectrical element as described above. Additionally or alternatively, the contact portion may comprise an elastic and/or spongy material that may expand to a size that is suitable for contacting the target portion. The contact portion may generally be self-expanding.

The earcanal piece may comprise a portion configured for being located at the isthmus of the ear canal, wherein an uncompressed maximum width of this portion is configured to be equal to or smaller than the narrowest width of the ear canal at the isthmus. The isthmus is the narrowest portion of the ear canal. In this manner, unnecessary pressure by the ear canal piece on the ear canal wall at the isthmus may be reduced. This is particularly advantageous for long-term applications. Again, the width of the ear canal is defined as the width that is relevant for the passage of the earcanal piece. The narrowest width of the ear canal at the isthmus may be defined as the smallest diameter of the ear canal in a cross section that is perpendicular or at an angle to the longitudinal direction and/or axis of the ear canal at the isthmus. The longitudinal axis of the ear canal may be defined as a curve extending in the center of the ear canal along a longitudinal direction of the ear canal (i.e., from its opening at the auricular concha to the tympanic membrane).

Alternatively, the earcanal piece may comprise a portion configured for being located at the isthmus of the ear canal, wherein the portion is configured to be collapsible to a width that is equal to or smaller than the narrowest width of the ear canal at the isthmus. This is advantageous in cases in which the earcanal piece is non-customized, for example in cases in which the earcanal piece is to be used with several different subjects. It is particularly suitable for short-term applications.

The portion configured for being located at the isthmus may be expandable from the collapsed state to an expanded state, wherein a ratio of the portion's maximum width in the expanded state to the portion's minimum width in the collapsed state is 1.2

A maximum width of the contact portion may be at least 2 times, preferably at least 3 times, a maximum width of the portion configured for being located at the isthmus of the ear canal.

The contact portion may have a shape that fits or essentially fits with the target portion of the ear canal. For example, the contact portion may have the shape of a cone , the shape of a truncated cone, a spherical shape, a truncated spherical and/or a cylindrical shape with a round or oval cross-section. The shape may also be a "double" cone or a double truncated cone, i.e. two cones or truncated cones that are connected to each other at their (wider) base. The shape may be cylindrical with a cone shaped end. An axis, preferably a central axis, of such cone(s) that extends from the basis to the apex, may be configured to essentially extend along the ear canal. It is also contemplated that the contact portion is custom fit.

The contact portion may be collapsible from the expanded state to the collapsed state for and/or upon passing the second turn and/or the isthmus of the ear canal. In cases in which the contact portion has a width in the expanded state that is larger than the narrowest width of the isthmus, such collapsible contact portion facilitates passage of the contact portion past the isthmus during insertion of the ear device into the ear canal. The contact portion may comprise one or more springs biased to press the contact surface radially outward against the target portion of the ear canal wall. This may allow to enhance the contact between the contact surface and the target portion. In addition, such springs may be configured to be provided in a collapsed configuration that facilitates passing the isthmus, if required.

The contact portion preferably comprises a hydrogel, optionally a shape-memory hydrogel, and/or silicone. Such hydrogel may ease insertion of the ear canal piece into the ear canal. Moreover, it may help in optimizing the shape and/or position of the contact surface. The hydrogel may have self-fitting properties, i.e. may be self-fitting as described above. This may also have the advantage of enhancing the contact of the contact portion and the target portion, particularly of the contact surface and the target portion.

Enhancing the contact in turn may result in an improvement of transport of thermal energy from the contact surface to the target portion and vice versa.

The individual components of the device may be arranged in any suitable way.

For example, the thermoelectrical element may be located in a tip portion of the earcanal piece. "Tip portion of the earcanal piece" refers to a portion of the earcanal piece that is close to the contact portion. For example, the thermoelectrical element may be located more inward in the ear canal than (i.e., distal of) the first turn, the second turn or the isthmus when the earcanal piece is inserted into the ear canal.

The thermoelectrical element may alternatively be configured to be located exterior to the ear canal, wherein the thermoelectrical element is thermally coupled to the contact portion and/or the contact surface via a thermal conduit, the thermal conduit preferably having a high thermal conductivity identical or different from the thermal conductivity of the contact surface and configured for transporting thermal energy between the contact portion and the thermoelectrical element.

"High thermal conductivity" in this context refers to the thermal conductivity of materials that a person skilled in the art would select if transportation of thermal energy is intended. "Low thermal conductivity" refers to the thermal conductivity of materials that a person skilled in the art would select if transport of thermal energy is not intended, i.e. if thermal insulation is required. High thermal conductivity may refer to a thermal conductivity of at least 1 W/m*K, at least 5 W/m*K, more preferably at least 10 W/m*K, more preferably at least 30 W/m*K, more preferably at least 50 W/m*K, more preferably at least 80 W/m*K and more preferably at least 100 W/m*K. A low thermal conductivity may refer to a thermal conductivity of 1 W/m*K or less, preferably 0,8 W/m*K or less, more preferably 0,5 W/m*K or less, more preferably 0,3 W/m*K or less, and more preferably 0,2 W/m*K or less.

The thermoelectric element may produce waste heat in the case of intended cooling of the contact surface/target portion or waste cooling in the case of intended heating of the contact surface/target portion. Having the thermoelectric element located exterior to the ear canal may support dissipation of waste heat and/or waste cooling. If the thermoelectric element is located in the tip portion of the earcanal piece, waste heat may be dissipated to the exterior (i.e. out of the ear canal) via a thermal waste conduit. All features mentioned with respect to the thermal conduit also apply mutatis mutandis to the thermal waste conduit.

The thermal conduit may have a high thermal conductivity, preferably a thermal conductivity of at least 5 W/m*K, more preferably at least 10 W/m*K, at least 100 W/m*K or at least 200 W/m*K, along the entire path from the thermoelectrical element to the contact surface. The thermal conduit may extend at least partially through the body. The body may have a surface with a low thermal conductivity, preferably a thermal conductivity of 1 W/m*K or less, whereby the body is configured to thermally insulate the thermal conduit. The body may surround the thermal conduit at least partially or entirely along most of the conduit's length.

The contact portion may comprise a sponge and/or fabric structure, preferably made from metal, silicone, polyester and/or polyamine. The contact portion may also be a sponge and/or fabric structure, preferably made from metal, silicone, polyester and/or polyamine. The sponge and/or fabric structure may comprise, particularly be coated and/or wetted with a gel, preferably a gel as described herein. The sponge and/or fabric structure may be flexible and/or elastic, for example in order to increase the adaptability to the target portion.

The thermal conduit may have any suitable shape.

The thermal conduit may have a round, an oval and/or a polygonal, preferably a triangular, square, pentagonal, hexagonal or heptagonal, cross section. Any combination of such shapes is also contemplated. However, the cross-section may also have an irregular shape. The shape of the conduit may accommodate the shape of the earcanal piece and particularly of the contact portion.

The contact portion may comprise two or more springs. For each spring the contact surface may comprise a corresponding contact surface section. The contact surface sections may be individually movable. Each spring may be biased to press the corresponding contact surface section radially outwardly against the target portion of the ear canal wall. For example, the thermal conduit may have a distal portion with a polygonal cross section, the polygonal cross section having N sides and N corners. The contact portion may comprise N springs and N corresponding contact surface sections. One spring may be coupled to the thermal conduit on each of the N sides.

Alternatively or additionally, the thermal conduit may have a distal portion with an oval, preferably a round, cross section, the cross section having N circumferential segments, and wherein the contact portion comprises N springs and N corresponding contact surface sections, with one spring and the corresponding contact surface section being coupled to each circumferential segment.

The one or more springs are may be cantilever springs and/or z-springs. Other suitable spring types are compression springs, coil springs, miniature leaf-springs, etc. An earcanal piece may comprise different types of springs, for example any combination of the spring types mentioned herein.

In some embodiments, when the earcanal piece is properly inserted into and adapted to the ear canal, the springs, the contact surface and the thermal conduit may leave some space of the ear canal unoccupied. This space may be air-filled. Alternatively, the space around the springs and the thermal conduit may comprise, preferably be filled with, a compressible and/or elastic foam configured to stabilize the springs. This may also limit entangling with ear canal hairs, thus reducing the amount of teared out ear canal hairs. This may also protect the ear drum by a soft layer between the tip of the ear canal piece and the ear drum.

The ear device may further comprise one or more sensors configured to monitor the temperature of the contact surface and/or the ear canal wall. For example, the one or more sensors may be integral with and/or coupled to the thermoelectrical element. The ear device may also comprise the sensors as elements that are separate from the thermoelectrical element. The latter is particularly suitable for embodiments with the thermoelectrical element located exterior to the ear canal.

The ear device, and particularly its components, may be configured for different applications in terms of duration. Embodiments may be specifically adapted for short-term applications and/or for long-term applications.

Particularly, the ear device may be configured for warming and/or cooling for at least 5 min, preferably at least 10 min, more preferably at least 20 min, more preferably at least 30 min, more preferably at least 60 min, most preferably at least 90 min. The longer the application, the more important is a proper overall heat balance, i.e. a proper dissipation of waste heat and/ waste cooling.

The ear device may comprise a conchal bowl portion configured to be worn in and/or at the conchal bowl and comprising the thermoelectric element. In this context, the dissipation of waste heat and/or waste cooling via the surrounding air may be sufficient in certain applications, for example with short durations and/or moderate heating and/or cooling.

The ear device, however, may also comprise a passive and/or an active, external cooling unit.

The external cooling unit may be thermally coupled to the thermoelectric element and support the dissipation of waste heat. A passive external cooling unit may be a device with a large surface area as compared to its volume, for example a heat sink with lamellae.

The external active cooling unit may be any suitable device and/or comprise any suitable device. For example, the external cooling unit may include water cooling, forced air cooling (e.g. with a ventilator), or cooling with any other suitable cooling fluid.

The ear device may comprise a suitable power source, e.g. a battery. Alternatively or additionally, the ear device may comprise a connector for connection to an external power source such as a power grid, a power generator, and/or an external battery. Connection may occur directly, for example a direct connection to the power grid via a respective plug, or indirectly via intermediate devices, such as controllers and the like.

According to a further aspect, the present invention relates to a system for inducing temperature changes in the inner ear and/or labyrinth of a subject, the system comprising a controller and a first ear device as described herein, the first ear device being operatively connected to the controller. The controller is configured for controlling the first ear device.

The system may further comprise a second ear device as described herein, the second ear device being operatively connected to the controller, wherein the controller is configured for controlling the second ear device.

The system may be configured for automated and/or semi-automated usage of the ear device(s).

The controller may be configured to control the first and second ear devices simultaneously. In the system, the earcanal piece of the first ear device may be configured for at least partial insertion into a first ear canal of a subject and the earcanal piece of the second ear device may be configured for at least partial insertion into the second ear canal of the subject.

The system may further comprise a holder configured to be worn on the subject's head and configured to be mechanically coupled to and support the ear device(s). This may increase the comfort of the subject when wearing the ear device(s). For example, the holder may support a part of the weight of the ear device(s), particularly external portions of the ear device(s), such as an external cooling unit, thus reducing the load on the ear and/or ear canal of the subject.

The system and particularly the controller and/or the earcanal pieces may be adapted to perform specific heating and/or cooling procedures. In other words, the controller may be configured to control the temperature at the contact surface by providing electric energy to the thermoelectric element. The thermoelectric element is configured to convert the electric energy to (directly or indirectly) induce a temperature change at the contact surface.

In the system, the earcanal pieces of the first and second ear devices may be configured to cool and/or heat a posterior surface of the first and second ear canals of the subject proximate the ear drum, respectively. Preferably, the system is configured for controlling the first and second ear devices via the controller while the subject is in supine position with an elevated head, preferably at 10° to 50°, more preferably 20° to 40°, most preferably about 30°, as measured relative to a horizontal plane.

The controller may be configured to control the ear devices according to the following steps, in the order in which the steps are stated below: a) Warming of the first ear canal of the subject, preferably for a period of 15 to 120 s. b) Stopping the warming of step a) and pausing, preferably for at least 60 s, at least 120 s, most preferably at least 300 s. c) Warming of the second ear canal of the subject, preferably for a period of 15 to 120 s. d) Stopping the warming of step c) and pausing, preferably for at least 60 s, at least 120 s, most preferably at least 300 s. e) Cooling one of the first and second ear canals, preferably for 15 to 120 s; f) stopping the cooling step e) and pausing, preferably for at least 60 s, at least 120 s, most preferably at least 300 s. g) Cooling the other one of the first and second ear canals, preferably for 15 to 120 s.

While the controller controls the ear devices in this manner, the subject is preferably in supine position with an elevated head, preferably at 10° to 50°, more preferably 20° to 40°, most preferably about 30°, as measured relative to a horizontal plane.

Alternatively or additionally, the controller may be configured to control the ear devices according to the following steps, in the stated order: a) Warming of the first ear canal and simultaneous cooling of the second ear canal of the subject, preferably for a period of 15 to 120 s. b) Stopping the warming and cooling of step a) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min. c) Warming of the second ear canal and simultaneous cooling of the first ear canal of the subject, preferably for a period of 15 to 120 s; d) Stopping the warming and cooling of step c) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min.

While the controller controls the ear devices in this manner, the subject is preferably in supine position with an elevated head, preferably at 10°-50°, more preferably 20°-40°, most preferably 30°, as measured relative to a horizontal line.

Alternatively or additionally, the controller may be configured to control the ear device according to the following steps, in the stated order: a) Simultaneous warming of the first ear canal and the second ear canal of the subject, preferably for a period of 15 to 120 s. b) Stopping the warming of step a) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min. c) Simultaneous cooling of the first and second ear canals of the subject, preferably for a period of 15 to 120 s. d) Stopping the cooling of step c) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min.

While the controller controls the ear devices in this manner, the subject is preferably in supine position with an elevated head, preferably at 10° to 50°, more preferably 20° to 40°, most preferably about 30°, as measure relative to a horizontal line. The skilled person will appreciate that in the method steps stated above, warming or cooling the first and second ear canals is performed by controlling the first and second ear devices accordingly. In other words, where reference is made above to warming or cooling the first and/or second ear canals for certain periods of time, this is equivalent to controlling the first and/or second ear devices, respectively, to heat or cool for the stated time periods.

The system may further comprise an eye-tracking system, such as eye tracking goggles, preferably video-oculography goggles and/or virtual reality goggles. The controller may be operably connected to the eye-tracking system. The eye tracking system may be configured to record eye movement of the subject during stimulation, i.e. during heating and/or cooling of the target portion, and optionally at least 60 s or at least 120 s after the warming steps and/or the cooling steps. The system may be configured for correlating the recording of the eye movement with the thermal stimulation of the subject.

Any suitable recording mode may be used. For example, recording of eye movement of the subject may start shortly before and/or with the start of the stimulation and continue until the end of the stimulation, optionally until at least 60 s or at least 120 s after the last stimulation step. Alternatively, recording of the eye movement may be interrupted between individual stimulation steps. In this case, recording of the eye movement may start shortly before or with the start of each individual stimulation step (i.e. step A), step B), step C), step D), etc.) and stop with, shortly after, preferably 120 s after, the end of each individual stimulation step.

Eye tracking goggles as mentioned herein are known in the art. Specific examples are the ICS Impulse from Natus, or the VisualEyes 515 from Interacoustics.

The system may be configured to determine nystagmus and to adapt the steps upon determination of robust nystagmus. The system may be configured to determine nystagmus automatically. The system may be configured to adapt the steps upon determination of robust nystagmus automatically. Alternatively and/or additionally, the system may be configured to allow a user (e.g., the subject, a physician or nurse) to adapt the steps upon determination of robust nystagmus.

The system may be configured to stop an ongoing warming and/or cooling step upon determination of robust nystagmus and to proceed with the next step. The system may be configured to do this automatically, i.e. to automatically determine robust nystagmus, to automatically stop an ongoing warming and/or cooling step upon determination of robust nystagmus and to automatically proceed with the next step. Alternatively and/or additionally, the system may be configured to allow a user to influence the automatic procedure. For example, a user may be allowed to set threshold parameters, e.g. for determination of robust nystagmus. Alternatively and/or additionally, the system may be configured to allow a user, e.g. a physician, to perform each of the above-mentioned steps manually, namely only one of these steps, two of these steps or all three steps.

The ear device and/or the system may be configured for one of or a combination of the following: i. Therapeutic localized cryotherapy for the prevention of the loss of residual hearing during Cochlear Implant (Cl) surgeries. ii. Therapeutic localized cryotherapy, particularly in infectious diseases, otitis media, otitis media with complications, e.g. inner ear damage and/or purulent labyrinthitis, otitis externa, and Herpes zoster oticus. iii. Therapeutic localized cryotherapy for the facial nerve and vestibulo-cochlear nerve in Ramsay-Hunt-Syndrome and Bell paresis. iv. Rherapeutic localized cryotherapy for the prevention of ototoxic hearing loss, e.g. cisplatin chemotherapy or aminoglycoside antibiotic treatment. v. Ear blast injury, acoustic shock. vi. Noise-induced deafness, noise-induced hearing loss (NIHL) blast injury, acoustic shock. vii. Hearing impairment, sudden sensorineural hearing loss (SSHL), sudden deafness.

For example, the ear device and/or the system may be configurated for localized cryotherapy, in particular the application of hypothermia over the external ear canal, ear canal skin, the periost and the spongeous and labyrinthic bones of the lateral skull base towards the sensitive sensory and neural tissues of the inner ear (organ of corti and hair cells of the cochlea, maculae of the utricle, saccule and semicircular canals).

The earcanal piece may accommodate the anatomy, and particularly the angled anatomy of the ear canal. The feature "self-fitting" as mentioned above also refers to this aspect.

The earcanal piece may comprise a distal portion with a first longitudinal axis and a middle portion with a second longitudinal axis, the distal portion being configured to be arranged distal of the second turn of the ear canal and the middle portion being configured to be arranged proximal of the distal portion and proximal of the second turn of the ear canal, wherein the first longitudinal axis and the second longitudinal axis are configured to form an angle of at least 110° to at least 170° (view from front, coronalplane), and an angle of at least 130° to at least 175° (view from top, transverse plane) when inserted in the ear canal as intended. The first and second longitudinal axis may be provided by straight lines.

The earcanal piece may comprise a proximal portion with a third longitudinal axis, the proximal portion being configured to be arranged proximal of the first turn of the ear canal and the middle portion, wherein the third longitudinal axis and the second longitudinal axis are configured to form an angle of at least 110° to at least 170° (view from front, coronal plane), and an angle of at least 150° to at least 180° (view from top, transverse plane) when inserted in the ear canal as intended.

The ear device may comprise a housing, the housing being configured to be arranged outside of the ear canal and comprising a surface configured to be oriented towards the ear canal, wherein the third longitudinal axis and the surface of the housing are configured to form an angle of at least 70° to at least 100° (view from front, coronal plane), and an angle of at least 40° to at least 70° (view from top, transverse plane) hen the earcanal piece is inserted in the ear canal as intended.

Accommodating the angled anatomy of the human ear canal may be achieved by any suitable means. For example, the ear canal piece may be sufficiently flexible to follow the longitudinal shape of the ear canal, i.e. the first and second turns, when being inserted into the ear canal of a subject. This longitudinal flexibility may arise from the flexibility of the material(s) of the ear canal piece. The flexibility of the ear canal piece may also be achieved by mechanical means. For example, the ear canal piece may comprise the distal portion, the middle portion and the proximal portion, wherein the distal portion is connected to the middle portion via a joint and/or hinge, and/or wherein the middle portion is connected to the proximal portion via a joint and/or hinge.

The hinge or hinges may be implemented in any suitable configuration. For example, the hinge(s)/joint(s) may comprise a material with a higher flexibility than the proximal, middle and distal portions. The flexibility of the hinge(s)/joint(s) may also result from the geometry of these portions. For example, the hinges/joints may comprise a smaller width as compared to the proximal, middle and distal sections, thus enabling flexing of the hinges/joints. The hinges/joints may also comprise one or more mechanical components, e.g. pins and knuckles.

Herein, "flexible"/"flexibility" may particularly mean "elastic"/"elasticity". For example, the earcanal piece, and particularly the body, may be sufficiently elastic to follow the longitudinal shape of the ear canal, i.e. the first and second turns, when being inserted into the ear canal of a subject. The body may have a natural conformation, i.e. a conformation the body has when no forces act on it. The natural conformation may be adapted to the shape of the ear canal of a subject in advance. The natural conformation may also be suitable to fit a large number of subjects. The body may be configured to be driven out of its natural conformation when being inserted into the ear canal, thus being able to pass the windings of the ear canal. In other words, the ear canal wall restricts the space for the earcanal piece and thus the earcanal wall elastically deforms the earcanal piece upon insertion into the ear canal. However, when the earcanal piece is at its intended position in the ear canal, the earcanal piece may return to its natural conformation. This may allow for a relatively painless insertion procedure and/or a relatively painless final position of the earcanal piece.

The earcanal piece may comprise a channel, the channel extending from a distal end and/or portion of the ear canal piece to a proximal portion and/or end of the ear canal piece, wherein the channel is configured for allowing ventilation and/or transmission of sound. The channel may provide several advantages. The channel may enable ventilation of the ear drum when the earcanal piece is in the ear canal of the subject. Moreover, it may support discharge of air close to the ear drum during the insertion process of the earcanal piece, thus supporting a proper fit of the earcanal piece. Moreover, it may support sound transmission from outside and/or from the ear device(s) itself/themselves. For example, the ear device(s) may comprise a loudspeaker that is configured for providing music and/or instructions from an investigator/physician and/or the control unit to the subject.

The housing of the ear device may comprise the cooling unit, the thermoelectric element, the loudspeaker and/or a temperature sensor. The housing may comprise one or more indicators that indicate an operation mode. For example, the housing may comprise a red light configured for being illuminated during heating and a blue light configured for being illuminated during cooling.

The earcanal piece may comprise a body core, i.e. an inner portion, that is surrounded by a body shell, i.e. an outer portion. Body core and body shell may be configured to essentially define the overall mechanical properties of the earcanal piece body. The self-fitting and/or self-expanding properties of the earcanal piece may result from the body core and the body shell comprising different materials and/or structures. For example, the body core may be more flexible than the body shell, or vice versa. The less flexible part may provide for sufficient stability for insertion of the earcanal piece into the ear canal, while the more flexible part may provide for self-fitting properties. The more flexible part, e.g. in the case of the shell being the more flexible part, may comprise a gel as described herein. As already mentioned above, "flexible" may mean "elastic". The body core and body shell having different materials and/or structures may, additionally or alternatively, contribute to and/or form the hinges/joints of the ear canal piece, i.e. contribute to the longitudinal flexibility. For example, the less flexible material may have a reduced thickness at the hinges/joints, thus enabling the proximal, middle and distal portions to accommodate the turns of the ear canal.

The body core may comprise, optionally be, the thermal conduit and/or the thermal waste conduit. Remaining portions of the body, particularly the body shell, may be configured to, at least partially, thermally insulate the thermal conduit and/or the thermal waste conduit.

The following aspects are preferred embodiments of the invention:

1. An ear device for inducing temperature changes in the inner ear and/or labyrinth of a subject, comprising: a thermoelectrical element; and an at least partially flexible earcanal piece comprising a body and a contact portion, the earcanal piece being configured for at least partial insertion into an ear canal of the subject, the ear canal having an ear canal wall, the earcanal piece being configured such that, when inserted in the ear canal, a contact surface of the contact portion contacts a target portion of the ear canal wall proximal to the tympanic membrane, and

- distal of the ear canal isthmus and the second turn of the ear canal, and/or in the bony part of the ear canal, for transferring thermal energy between the target portion and the ear device via the contact surface; wherein the contact portion is expandable from a collapsed state to an expanded state, wherein in the expanded state the contact portion, preferably its width, is configured such that the contact surface contacts the target portion of the ear canal wall for transferring thermal energy between the target portion and the ear device via the contact surface; wherein the thermoelectrical element is thermally connected to the contact surface and configured for regulating a temperature of the contact surface; and optionally wherein in the collapsed state the contact portion, and preferably its width, is configured for passing the second turn and the isthmus, and/or for reaching the bony part of the ear canal wall. The ear device of the previous aspect, wherein a ratio of the width of the contact portion in the expanded state to the width of the contact portion in the collapsed state is at least 1.2, preferably at least 2. An ear device for inducing temperature changes in the inner ear and/or labyrinth of a subject, comprising: an at least partially flexible earcanal piece configured for at least partial insertion into an ear canal of the subject, the ear canal having a first turn, a second turn, an ear canal isthmus and an ear canal wall, the earcanal piece comprising a body and a contact portion; and a thermoelectrical element; the earcanal piece being configured such that, when inserted in the ear canal, a contact surface of the contact portion contacts a target portion of the ear canal wall distal of the ear canal isthmus and the second turn of the ear canal and proximal to the tympanic membrane for transferring thermal energy between the target portion and the ear device via the contact surface; wherein the contact portion is expandable from a collapsed state to an expanded state, wherein in the collapsed state the contact portion, and preferably its width, is configured for passing the second turn and the isthmus, and wherein in the expanded state the contact portion, and preferably its width, is configured such that the contact surface contacts the target portion of the ear canal wall for transferring thermal energy between the target portion and the ear device via the contact surface, wherein a ratio of the width of the contact portion in the expanded state to the width of the contact portion in the collapsed state is at least 1.2, preferably at least 2; and wherein the thermoelectrical element is thermally connected to the contact surface and configured for regulating a temperature of the contact surface. The ear device of any one of the preceding aspects, wherein the thermoelectrical element is configured for providing a temperature of the contact surface above the natural subject's body core temperature, preferably an absolute temperature of about 44 °C to about 48 °C, and/or a temperature of the contact surface below the natural subject's body core temperature, preferably an absolute temperature of about 10 °C to about 30 °C. The ear device of any one of the preceding aspects, wherein the thermoelectrical element is configured for providing a subject's body temperature at the target portion above the natural subject's body core temperature, preferably an absolute temperature of about 44 °C to 48 °C, and/or a subject's body temperature at the target portion below the natural subject's body core temperature, preferably an absolute temperature of about 10 °C to 30 °C. 6. The ear device of any one of the preceding aspects, wherein the contact surface has a high thermal conductivity, in particular a higher thermal conductivity than remaining portions of the ear device contacting the ear canal.

7. The ear device of any one of the preceding aspects, wherein the contact portion is self-fitting.

8. The ear device of the previous aspect, wherein the contact portion is self-expanding.

9. The ear device of any one of the preceding aspects, wherein the earcanal piece comprises a portion configured for being located at the isthmus of the ear canal, wherein an uncompressed maximum width of this portion is configured to be equal to or smaller than the narrowest width of the ear canal at the isthmus.

10. The ear device of any one of aspects 1-8, wherein the earcanal piece comprises a portion configured for being located at the isthmus of the ear canal, wherein the portion is configured to be collapsible to a minimum width that is equal to or smaller than the narrowest width of the ear canal at the isthmus.

11. The ear device of aspect 10, wherein the portion configured for being located at the isthmus is expandable from the collapsed state to an expanded state, wherein a ratio of the portion's maximum width in the expanded state to the portion's minimum width in the collapsed state is 1.2-2 .

12. The ear device according to any of the three preceding aspects, wherein a maximum width of the contact portion is at least 1.1 times, preferably at least 1.2 times or at least 1.3 times or at least 1.5 times, a maximum width of the portion configured for being located at the isthmus of the ear canal.

13. The ear device of any one of the preceding aspects, wherein the contact portion has a cone shape, a truncated cone shape, a spherical shape, a truncated spherical shape, a cylindrical shape, or a cylindrical shape with a cone shaped end.

14. The ear device of any one of the preceding aspects, wherein the contact portion is collapsible from the expanded state to the collapsed state for and/or upon passing the second turn and/or the isthmus of the ear canal.

15. The ear device of any one of the preceding aspects, wherein the contact portion comprises one or more springs, biased to press the contact surface radially outwardly against the target portion of the ear canal wall.

16. The ear device of any one of the preceding aspects, wherein the contact portion comprises a hydrogel, optionally a shape-memory hydrogel, and/or silicone.

17. The ear device of any one of the preceding aspects, wherein the thermoelectrical element is located in a tip portion of the earcanal piece.

18. The ear device of any one of aspects 1-16, wherein the thermoelectrical element is configured to be located exterior to the ear canal, wherein the thermoelectrical element is thermally coupled to the contact portion and/or the contact surface via a thermal conduit, the thermal conduit preferably having a high thermal conductivity identical or different from the thermal conductivity of the contact surface and configured fortransporting thermal energy between the contact portion and the thermoelectrical element.

19. The ear device of aspect 18, wherein the thermal conduit has a thermal conductivity of at least 5 W/m*K, more preferably a thermal conductivity of at least 10 W/m*K, along the entire path from the thermoelectrical element to the contact surface.

20. The ear device of one of the previous two aspects, wherein the thermal conduit extends at least partially through the body; and the body has a surface with a lower thermal conductivity than the thermal conduit, preferably a thermal conductivity of 1 W/m*K or less; whereby the body is configured to thermally insulate the thermal conduit.

21. The ear device of any one of the preceding aspects, wherein the contact portion comprises a sponge and/or fabric structure, preferably made from metal, silicone, polyester and/or polyamine.

22. The ear device of any one of aspects 18-21, wherein the thermal conduit has a round, an oval and/or a polygonal, preferably a triangular, square, pentagonal, hexagonal or heptagonal cross section.

23. The ear device of any one of aspects 15-22, wherein the contact portion comprises two or more springs, and wherein for each spring the contact surface comprises a corresponding contact surface section, wherein the contact surface sections are individually movable and wherein each spring is biased to press the corresponding contact surface section radially outwardly against the target portion of the ear canal wall, optionally wherein a space around the springs and/or the thermal conduit may comprise, preferably be filled with, a compressible and/or elastic foam configured to stabilize the thin springs and limit entangling with ear canal hairs and protect the ear drum.

24. The ear device of the previous aspect, wherein the thermal conduit has a distal portion with a polygonal cross section , the polygonal cross section having N sides and N corners, and wherein the contact portion comprises N springs and N corresponding contact surface sections, with one spring and the corresponding contact surface section being located on each side.

25. The ear device of any one of aspects 15-24, wherein the one or more springs are cantilever springs and/or z-springs.

26. The ear device of any one of the preceding aspects, wherein the target portion comprises a posterior surface of the ear canal, preferably a posterior surface of the ear canal close to the tympanic membrane in the bony part of the ear canal.

27. The ear device of any one of the preceding aspects, further comprising one or more sensors configured to monitor the temperature of the contact surface and/or the ear canal wall. 28. The ear device of any one of the preceding aspects, configured for warming and/or cooling for at least 5 min, preferably at least 10 min, more preferably at least 20 min, more preferably at least 30 min, more preferably at least 60 min, most preferably at least 90 min.

29. The ear device of any one of aspects 18-28, wherein the ear device comprises a conchal bowl portion configured to be worn in the conchal bowl and comprising the thermoelectric element.

30. The ear device of any one of aspects 18-29, wherein the ear device comprises a passive and/or an active, external cooling unit.

31. A system for inducing temperature changes in the inner ear and/or labyrinth of a subject, comprising a controller; and a first ear device according to any one of the preceding aspects, the first ear device being operatively connected to the controller; wherein the controller is configured for controlling the first ear device.

32. The system of the previous aspect, further comprising - a second ear device according to any one of aspects 1-30, the second ear device being operatively connected to the controller, wherein the controller is configured for controlling the second ear device.

33. The system of the previous aspect, wherein the controller is configured to control the first and second ear devices simultaneously.

34. The system according to one of the two previous aspects, wherein the earcanal piece of the first ear device is configured for at least partial insertion into a first ear canal of a subject and the earcanal piece of the second ear device is configured for at least partial insertion into the second ear canal of the subject.

35. The system according to any one of aspects 31 to 34, comprising a holder configured to be worn on the subject's head and configured to be coupled to and support the ear device(s).

36. The system according to any one of the previous two aspects, wherein the earcanal pieces of the first and second ear devices are configured to cool and/or heat a posterior surface of the first and second ear canals of the subject proximate the ear drum, respectively; and wherein the controller is configured to control the ear devices according to the following steps in this order: a) warming of the first ear canal of the subject, preferably for a period of 15-120 s; b) stopping the warming step a) and pausing, preferably for at least 2 min, more preferably at least 5 min, most preferably at least 10 min c) warming of the second ear canal of the subject, preferably for a period of 15-120 s; d) stopping the warming step c) and pausing, preferably for at least 2 min, more preferably at least 5 min, most preferably at least 10 min e) cooling one of the first and second ear canals, preferably for 15-120 s; f) stopping the cooling step e) and pausing, preferably 2 min, more preferably at least 5 min, most preferably at least 10 min; cooling the other one of the first and second ear canals, preferably for 15-120 s: wherein the subject is preferably in supine position with an elevated head, preferably at 10°-50°, more preferably 20°-40°, most preferably 30°, as measured relative to a horizontal line. The system according to aspect 34 or 35, wherein the earcanal pieces of the first and second ear devices are configured to cool and/or heat the posterior surface of the first and second ear canals of the subject proximate the ear drum, respectively; and wherein the controller is configured to control the ear devices according to the following steps in this order: a) warming of the first ear canal and simultaneous cooling of the second ear canal of the subject, preferably for a period of 15-120 s; b) stopping the warming and cooling step a) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min; c) warming of the second ear canal and simultaneous cooling of the first ear canal of the subject, preferably for a period of 15-120 s; d) stopping the warming and cooling step c) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min; wherein the subject is preferably in supine position with an elevated head, preferably at 10°-50°, more preferably 20°-40°, most preferably 30°, as measured relative to a horizontal line. The system according to clam 34 or 35, wherein the earcanal pieces of the first and second ear devices are configured to cool and/or heat the posterior surface close to the tympanic membrane, respectively; the controller being configured to control the ear device according to the following steps in this order: a) simultaneous warming of the first ear canal and the second ear canal of the subject, preferably for a period of 15-120 s; b) stopping the warming step a) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min; c) simultaneous cooling of the first and second ear canals of the subject, preferably for a period of 15-120 s; d) stopping the cooling step c) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min; wherein the subject is preferably in supine position with an elevated head, preferably at 10°-50°, more preferably 20°-40°, most preferably 30°, as measure relative to a horizontal line. The system according to any one of aspects 31-38, wherein the controller is operably connected to an eye-tracking system, preferably eye tracking goggles, more preferably video-oculography goggles and/or virtual reality goggles; and wherein the eye tracking system is configured to record eye movement of the subject during stimulation and optionally to continue for at least 120 s or longer after the warming steps and/or the cooling steps. The system according to the previous aspect, wherein the system is configured to determine nystagmus and to adapt the steps upon determination of robust nystagmus. The system according to the previous aspect, wherein the system is configured to stop an ongoing warming and/or cooling upon determination of robust nystagmus and to proceed with the next step. The ear device or system according to any one of the preceding aspects, the system configured for one of or a combination of the following: i. therapeutic localized cryotherapy for the prevention of the loss of residual hearing during Cochlear Implant (Cl) surgeries; ii. therapeutic localized cryotherapy, particularly in infectious diseases, otitis media, otitis media with complications, e.g. inner ear damage and/or purulent labyrinthitis, otitis externa, and Herpes zoster oticus; iii. therapeutic localized cryotherapy for the facial nerve and vestibulo-cochlear nerve in Ramsay-Hunt-Syndrome and Bell paresis; iv. therapeutic localized cryotherapy for the prevention of ototoxic hearing loss, e.g. cisplatin chemotherapy or aminoglycoside antibiotic treatment; v. ear blast injury, acoustic shock; vi. noise-induced deafness, noise-induced hearing loss (NIHL) blast injury, acoustic shock; vii. hearing impairment, sudden sensorineural hearing loss (SSHL), sudden deafness. The ear device or system according to any one of the preceding aspects, wherein the earcanal piece accommodates the angled anatomy of the ear canal. The ear device or system according to the previous aspect, wherein the earcanal piece comprises a distal portion with a first longitudinal axis and a middle portion with a second longitudinal axis, the distal portion being configured to be arranged distal of the second turn of the ear canal and the middle portion being configured to be arranged proximal of the distal portion and distal of the first turn of the ear canal, wherein the first longitudinal axis and the second longitudinal axis are configured to form an angle of at least 110° to at most 170° (view from front, coronal plane), and an angle of at least 130° to at most 175° (view from top, transverse plane) when inserted in the ear canal as intended. The ear device or system according to one of the previous two aspects, wherein the earcanal piece comprises a proximal portion with a third longitudinal axis, the proximal portion being configured to be arranged proximal of the first turn of the ear canal and the middle portion, wherein the third longitudinal axis and the second longitudinal axis are configured to form an angle of at least 110° to at most 170° (view from front, coronal plane), and an angle of at least 150° to at most 180° (view from top, transverse plane) when inserted in the ear canal as intended. The ear device or system according to the previous aspect as depending from aspect 42, wherein the distal portion is connected to the middle portion via a joint and/or hinge, and wherein the middle portion is connected to the proximal portion via a joint and/or hinge. The ear device or system according to any one of the preceding aspects, wherein the earcanal piece comprises a channel, the channel extending from a distal end and/or portion of the ear canal piece to a proximal portion and/or end of the ear canal piece, wherein the channel is configured for allowing ventilation and/or transmission of sound. The ear device or system according to any one of the preceding aspects, wherein the ear device comprises a loudspeaker. The ear device or system according to any one of the preceding aspects, wherein the ear device comprises a housing, the housing comprising one or a combination of: the thermoelectric element, the loudspeaker, the one or more temperature sensor, one or more indicators that indicate an operation mode such as a red light configured for being illuminated during heating and a blue light configured for being illuminated during cooling. The ear device or system according to any one of the preceding aspects, wherein the contact portion comprises an inflatable balloon. The ear device or system according to any one of the preceding aspects, wherein the at least partially flexible earcanal piece is at least partially elastic. The ear device or system according to any one of the preceding aspects, wherein the earcanal piece/s has/have a width in the transverse body plane of at least 2 mm to 4 mm, preferably 4 to 6 mm, at most 10 mm in the collapsed state, and/or wherein the earcanal piece has a width in the transverse body plane of at least 5 mm to 6 mm, preferably 6 to 9 mm, and/or at most 16.5 mm in the expanded state. The ear device or system according to any one of the preceding aspects, wherein the ear device is configured for transferring thermal energy between the target portion and the ear device via the contact surface in the absence of a fluid, such as water, flushing the ear canal/s. 54. The ear device or system according to any one of the preceding aspects, wherein the natural subject's body core temperature is 37°C.

In the following, specific embodiments of the invention will be described with reference to the Figures. These specific embodiments are not to be understood in a limiting way and features that are described in the context of one embodiment may be combined with features that are described in the context of another embodiment. The figures are of schematic nature and not necessarily drawn to scale.

Figure 1 schematically shows the anatomy of a human ear.

Figure 2 schematically shows features according to the present invention (cross sectional view).

Figure 3 schematically shows variations of the features of Figure 2 (cross sectional view).

Figure 4 schematically shows further variations of the features of Figure 2 (cross sectional view).

Figures 5a and 5b schematically illustrate angles between longitudinal axes extending through portions of an earcanal piece of a device according to the present invention.

Figure 6 schematically illustrates a device according to the present invention having an earcanal piece with a coating provided thereon.

Figure 7 schematically illustrates a device according to the present invention having an earcanal piece with an air channel extending therethrough.

Figure 8 schematically shows an exploded view of a housing of an ear device according to the present invention.

Figures 9a and 9b schematically illustrate a further variation of a contact portion of the devices according to any of the previous figures.

Figure 10 schematically illustrates the device of Figures 9a and 9b in the ear canal of a user and the mode of operation.

Figure 11 provides a more detailed schematic view of the contact portion of the device according to Figures 9 and 10.

Figure 12 schematically illustrates a system according to the present invention. Figure 1 shows the anatomy of a right human ear 1. Figure 1 shows a schematic ear 1 with ear canal 2, inner ear with the semicircular canals 3 and conchal bowl 4, the first turn 6 of the ear canal 2 and the second turn 8 of the ear canal 2. The second turn 8 of the ear canal 2 is often also referred to as a bend. The ear canal 2 is defined by the ear canal wall 10. Moreover, Figure 1 shows the isthmus 12, which is the narrowest part of the ear canal 2, in other words the bottle neck, as well as the ear drum 14, which is also called tympanic membrane 14. A target portion 112 for cooling and/or heating as targeted in the context of the present invention is also shown. The inner portion of the ear canal 2 is the bony part of the ear canal 2. It is located between the isthmus 12 and the ear drum 14. The cartilage part of the ear canal 2 is located proximal to the isthmus 12.

Figure 2 shows an ear device 100 according to the present invention. It comprises an at least partially flexible earcanal piece 102 configured for at least partial insertion into an ear canal 2 of a subject. The earcanal piece 102 comprises a body 104 and a contact portion 106. The ear device 100 comprises a thermoelectrical element 108. The earcanal piece 102 is configured such that, when inserted in the ear canal 2, a contact surface 110 of the contact portion 106 contacts a target portion 112 of the ear canal wall 10 distal of the ear canal isthmus 12 and the second turn 8 of the ear canal 2 and proximal to the tympanic membrane 14 for transferring thermal energy between the target portion 112 and the ear device 100 via the contact surface 110. The contact surface 110 may, additionally or alternatively, contact the target portion 112 of the ear canal wall 10 in the bony part of the ear canal 2 and proximal to the tympanic membrane 14 for transferring thermal energy between the target portion 112 and the ear device 100 via the contact surface 110

The contact portion 106 is expandable from a collapsed state to an expanded state, wherein in the collapsed state the contact portion 106, and particularly its width W, is configured for passing the second turn 8 and the isthmus 12, and wherein in the expanded state the contact portion 106, and particularly its width W, is configured such that the contact surface 110 contacts the target portion 112 of the ear canal wall 10 for transferring thermal energy between the target portion 112 and the ear device 100 via the contact surface 110.

A ratio of the width W of the contact portion 106 in the expanded state to the width W of the contact portion 106 in the collapsed state is at least 1.2, preferably at least 2.

The thermoelectrical element 108 is thermally connected to the contact surface 110 and configured for regulating a temperature of the contact surface 110.

As shown in Figure 2, the earcanal piece 102 may comprise a body core 104a and a body shell 104b. As indicated in Figure 2, in addition to a distal portion 114, the earcanal piece 102 may comprise a middle portion 116 and a proximal portion 118, with a distal hinge 120 connecting the distal and the middle portions 114, 116 and a proximal hinge 122 connecting the middle portion 116 and the proximal portion 118. As shown, the hinges 120, 122 may be formed of body core portions with an increased flexibility as compared to other portions of the body core 104a. Thus, a longitudinal flexibility of the earcanal piece 102 is provided that allows the earcanal piece 102 to accommodate the turns 6, 8 of the ear canal 2.

As shown in Figure 3, the hinges 120, 122 may alternatively or additionally be formed of body shell portions with an increased flexibility as compared to other portions of the body shell 104b.

As shown in Figure 4, the hinges 120, 122 may alternatively or additionally be formed of body shell portions with a reduced width as compared to other portions of the body shell 104b. The hinges 120, 122 may alternatively or additionally be formed of body core portions with a reduced width as compared to other portions of the body core 104a (not shown). Any alternative hinge/joint 120, 122, particularly as mentioned herein, is possible. It is preferred to reduce the width of the less flexible material for the hinges/joints.

Any combination of the features mentioned with respect to Figures 2 to 4 is possible. For example, the distal hinge 120 may comprise a body core portion with an increased flexibility as compared to other portions of the body core 104a, while the proximal hinge 122 may comprise a body shell portion with an increased flexibility as compared to other portions of the body shell 104b, or vice versa.

The body core 104a may be made from a material that is less flexible than the material forming the body shell 104b. The body core 104a may thereby provide the necessary stability for insertion of the earcanal piece 102 into the ear canal 2. The body shell 104b may be self-fitting, and particularly self-expanding. In a preferred embodiment, the body shell 104b comprises a shape memory material, e.g. a hydrogel. Prior to insertion of the earcanal piece 102 into the ear canal 2, the width of the earcanal piece (including the body core and the body shell) may be sufficiently small to permit insertion of the earcanal piece 102 into the ear canal 2, and particularly to allow for the distal portion 114 to pass the isthmus 12. The earcanal piece 102 and particularly the body shell 104b may be configured to adapt, at least partially, to the shape of the ear canal and optionally to the shape of the target portion 112. The respective change in shape may occur, e.g., upon the temperature change from room temperature (or a cooler, i.e. a refrigerated temperature) to the natural temperature of the ear canal 2. Additionally or alternatively, the change in shape may occur upon heating to a certain threshold temperature as known in the art. Any other trigger is contemplated. In an alternate embodiment, the body core 104a may comprise a more flexible material than the body shell 104b and the features described above and particularly with Figures 2-4 apply mutatis mutandis. For example, the body shell 104b may provide for the necessary stability for insertion of the earcanal piece 102 into the ear canal 2.

Having different flexibilities of body shell 104b and body core 104a may contribute to the possibilities of setting the mechanical properties of the body.

As already mentioned above, "flexible"/"flexibility" may mean "elastic"/"elasticity". Particularly, the earcanal piece 102 may be elastic and have a natural conformation. The natural conformation may correspond to the, particularly longitudinal, shape of the ear canal 2 of a subject and/or a group of subjects. For example, in the natural state of the earcanal piece 102, the proximal, middle and distal portions 118, 116, 114 may assume angles relative to each other as described below. Due to the elasticity of the earcanal piece 102, the earcanal piece 102 may be configured to be deformed during insertion into the ear canal 2 and to resume its natural state when in its final position. This may contribute to a comfortable feeling during the insertion procedure and during wearing for the subject.

Figures 5a and 5b show a front view and a top view of an ear device for the right ear 100, respectively.

Figure 5a illustrates angle aC between the distal portion 114, preferably its longitudinal axis 114a, and the middle portion 116, preferably its longitudinal axis 116a, in a coronal plane, i.e. perpendicular to the chest-back-axis, as well as angle PC between the middle portion 116, preferably its longitudinal axis 116a, and the proximal portion 118, preferably its longitudinal axis 118a, in the coronal plane, and angle yC between the proximal portion 118, preferably its longitudinal axis 118a, and a housing 124 in the coronal plane. aC, PC and yC are defined as the angles in the coronal plane (view from front) with aC being located below the earcanal piece 102, and PC and yC being located above the ear canal piece 102. This is also shown in Fig. 5a. For example, aC may be at least 110°, preferably 150°, at most 170°. PC may be at least 110°, preferably 150°, at most 170°. yC may be at least 70°, preferably 90°, at most 100°. In the cases of aC and PC "angle between X and Y" may mean "angle between the longitudinal axis of X and the longitudinal axis of Y".

Figure 5b illustrates angle aT between the distal portion 114 and the middle portion 116 in a transverse plane, i.e. perpendicular to the head-feet-axis, as well as angle PT between the middle portion 116 and the proximal portion 118 in the transverse plane, and angle yT between the proximal portion 118 and a housing 124 in the transverse plane. aT, PT and yT are defined as the angles in the transverse plane of the earcanal piece 102 as shown in Fig. 5b, i.e. in this view aT is below the earcanal piece 102, PT is above the earcanal piece 102 and yT is below the earcanal piece 102. Preferably, the angles are again defined between the longitudinal axes 114a, 116a and 118a of the distal portionll4, the middle portion 116 and the proximal portion 118, respectively. For example, aT may be at least 150°, preferably 170° , at most 180°. PT may be at least 130°, preferably 160° at most 175°. yT may be at least 40°, preferably 60°, at most 70°. In the cases of aT and PT "angle between X and Y" may mean "angle between the longitudinal axis of X and the longitudinal axis of Y".

As shown in Figures 6 and 7, the earcanal piece 102 may comprise an additional coating 125, which may facilitate insertion of the earcanal piece 102 into the ear canal. The coating 125 may be provided on said body shell 104b.

As shown in Figure 7, the ear device 100 may comprise a channel 126. The channel 126 may extend from a distal end 128 of the ear canal piece 102 to a proximal end 130 of the ear canal piece 102. The channel 126 may be configured for allowing ventilation and/or transmission of sound through the earcanal piece 102. The channel 126 may enable ventilation of the ear drum, and/or support discharge of air close to the ear drum during the insertion process, and/or it may support sound transmission from outside and/or from the ear device(s) itself/themselves. As shown, the ear device(s) may comprise a loudspeaker 132 that is configured for providing music and/or instructions from an investigator/physician and/or the control unit to the subject.

As shown in Figure 8, the ear device 100 may comprise the thermoelectrical element 108 located in housing 124, the housing 124 being configured to remain outside the ear canal. The housing 124 may comprise a cooling unit, e.g. a heat sink 134, the thermoelectrical element 108, the loudspeaker 132 and/or a temperature sensor 136. The housing 124 may comprise one or more indicators 138 that indicate an operation mode. For example, the housing may comprise a red light configured for being illuminated during heating and a blue light configured for being illuminated during cooling. The housing 124 may comprise a cover plate 190 configured for connection with the earcanal piece. Such connection may be permanent or reversible. A reversible connection may be useful in that it enables an exchange of the earcanal piece, e.g. for different subjects, while the housing remains the same and may be reused, thus avoiding unnecessary waste. Furthermore, a temperature sensor 133 may be provided in the housing, e.g. proximate the thermoelectrical element 108 to assess the temperature of the thermoelectrical element 108.

Figures 9a and 9b show an embodiment of the ear device 100 with an exemplary earcanal piece 102 in front and top view, respectively. The ear device is shown with the housing 124 and distal, middle and proximal portions 114, 116, 118 as described above. As shown in Figures 9a and 9b, the distal portion 114 may comprise a contact portion 106 with springs 140 that are biased to push the contact surface 110 radially outward. The contact surface 110 may be divided into several portions 110a that are movable independently from one another. As shown in Figure 10, this improves the adaptability to the target portion 112. The springs may be configured to allow a compression of the contact portion 106 to a collapsed state upon and for passing the isthmus 12 and for expansion to an expanded state when having passed the isthmus 12.

Any suitable specific implementation of the spring(s) 140 and contact surface 110/contact surface portions 110a is contemplated. Figures 2 and 3 show two embodiments. As shown in figs. 2 and 3, the spring(s) 140 may have various shapes, be e.g. circular/cylindrical springs and/or leaf springs (Fig. 2). As shown in fig. 3, the spring(s) 140 may have a straight shape. The number of shown contact surface portions 110a and springs is only exemplary and may be selected as appropriate, e.g. according to the size of the ear canal 2 and/or target portion 112. These features of the contact portion 110 may be combined with features that are shown in other figures and/or without the other features shown in Figs. 2 and 3. In other words, the features of the contact portion 110 shown in Figs. 2 and 3 are independent of the remaining features of these Figures. Vice versa, the other features shown in figs. 2 and 3 are independent of the shown features of the shown contact portions.

As shown in Fig. 4, the contact portion 110 of any ear device 100 according to the present invention, i.e. independently of the other features mentioned in fig. 4, may comprise a balloon. The balloon may be inflatable with a fluid, particularly a liquid, e.g. air or water. The ear device may comprise respective conduits for filling and emptying the balloon. In an empty state, the balloon may adapt a collapsed state and have a size that is suitable for passing the isthmus 12. In an at least partially filled state, the balloon may adapt to the shape of the target size.

As also shown in Figure 10, the exterior portions of the ear device, i.e. the housing 124, may be configured to be coupled to a holder 142 configured to be worn on the subject's head, for example on the pinna as shown, and/or over the top and/or crown of the head. The holder 124 may be configured to support the ear device 100. The holder may also be configured to be coupled to two ear devices 100, wherein one ear device 100 is configured for insertion into the right ear of the subject and the other ear device 100 is configured for insertion into the left ear of the subject. The box in Fig. 10, which shows a detailed view, illustrates a mode of operation. The contact surface 110, here the several contact surface portions 110a, are pressed onto the target region 112, i.e. the ear canal wall close to the ear drum and close to the semicircular canals 3. The arrows indicate the heat flux through the portions of the ear device 114, via the thermoconductive springs 140 to the contact surface 110/ several contact surface portions 110a.

As also shown in Figure 10, the ear device 100 may be connected to external devices and/or power via any suitable means, e.g. one or more cables 150.

Figure 11 shows the contact portion 106 of Figure 10 (in the embodiment with springs) in more detail. As shown, the springs 140 may be z-springs, but any other type of springs 140 is contemplated. The earcanal piece 102 may comprise a thermal conduit 144, which may have a polygonal cross-section, particularly a cross-section with six sides 146 and six corners 148. The contact surface 110 may be separated into several portions 110a, which may correspond to the sides 146 of the thermal conduit. Moreover, the contact surface 110 may also be divided into contact surface portions 110a in a longitudinal direction. The contact surface portions 110a may also have convex-shaped surfaces. In some embodiments, when the earcanal piece 102 is properly inserted into and adapted to the ear canal, the springs 140, the contact surface 110 and the thermal conduit 144 may leave some space 150 of the ear canal unoccupied. This space 150 may be air-filled. Alternatively, the space 150 around the springs 140 and the thermal conduit 144 may comprise, preferably be filled with, a compressible and/or elastic foam configured to stabilize the thin springs and limit entangling with ear canal hairs, thus reducing the amount of teared out ear canal hairs and protecting the ear drum. Examples of such a foam are: polyvinyl chloride (PVC), polyurethane (PU), thermoplastic elastomer (TPE) and/or silicone foam.

As illustrated by Figure 12, the present invention also relates to a system 200 for inducing temperature changes in the inner ear and/or labyrinth of a patient/subject. The system may comprise a first ear device 100a as described above. As shown in Figure 12, the system may comprise a controller 202. The first ear device 100a may be operatively connected to the controller 202. The controller 202 may be configured for controlling the first ear device 100a. The system 200 may further comprise a second ear device 100b as described herein, the second ear device 100b being operatively connected to the controller 202, wherein the controller 202 is configured for controlling the second ear device 100b. In Figure 12, the first ear device 100a is shown to be inserted into a right ear 1R of the subject and the second ear device 100b is shown to be inserted into a left ear IL of the subject. However, the arrangement may be vice versa. As shown, the ear devices 100a, 100b may be connected to the controller 202 via one or more cables 150. Alternatively or additionally, operative connection to the controller 202 may also be/occur via cable-free connections, e.g. electro-magnetic waves, e.g. Bluetooth and the like. Respective electronic components, e.g. transducers, may be comprised in the ear device(s) 100 and the controller 202. The controller 202 may be any suitable device, e.g. a computer, and may comprise a user interface 204. The user interface may be configured for receiving input from a user and/or for providing output to the user. The user interface may therefore comprise an input interface, e.g. a keyboard, a mouse and/or a joystick, and an output interface, e.g. a monitor.

The cable(s) 150 may also serve as connection(s) to an external power source (not shown), e.g. the power grid. Alternatively or additionally, the ear device(s) 100 may comprise internal power source(s) such as batteries (not shown).

The system 200 may be configured to perform heating and/or cooling of the contact surface(s) 110 of the ear device(s) 100 and thus the target portion(s)112 in the ear(s) 1.

As shown in Figure 12, the system 200 may comprise an eye-tracking system 206, preferably eye tracking goggles 206, more preferably video-oculography goggles and/or virtual reality goggles. The eye tracking system 206 may be configured to record eye movement of the subject during stimulation, i.e. heating and/or cooling of the target portion(s) 112, as described in detail above.

The system 200 may be configured for automated and/or semi-automated usage of the ear device(s) 100 as discussed above.

Claims

Claims An ear device for inducing temperature changes in the inner ear and/or labyrinth of a subject, comprising: an at least partially flexible earcanal piece configured for at least partial insertion into an ear canal of the subject, the ear canal having a first turn, a second turn, an ear canal isthmus and an ear canal wall, the earcanal piece comprising a body and a contact portion; and a thermoelectrical element; the earcanal piece being configured such that, when inserted in the ear canal, a contact surface of the contact portion contacts a target portion of the ear canal wall distal of the ear canal isthmus and the second turn of the ear canal and proximal to the tympanic membrane for transferring thermal energy between the target portion and the ear device via the contact surface; wherein the contact portion is expandable from a collapsed state to an expanded state, wherein in the collapsed state the contact portion, and particularly its width, is configured for passing the second turn and the isthmus, and wherein in the expanded state the contact portion, and particularly its width, is configured such that the contact surface contacts the target portion of the ear canal wall for transferring thermal energy between the target portion and the ear device via the contact surface, wherein a ratio of the width of the contact portion in the expanded state to the width of the contact portion in the collapsed state is at least 1.2, preferably at least 2; and wherein the thermoelectrical element is thermally connected to the contact surface and configured for regulating a temperature of the contact surface; wherein the target portion preferably comprises a posterior surface of the ear canal, preferably a posterior surface of the ear canal close to the tympanic membrane in the bony part of the ear canal. The ear device of claim 1, wherein the thermoelectrical element is configured for providing a temperature of the contact surface above the natural subject's body core temperature of 37°C, preferably an absolute temperature of about 44 °C to about 48 °C, and/or a temperature of the contact surface below the natural subject's body core temperature of 37°C, preferably an absolute temperature of about 10 °C to about 30 °C. The ear device of claim 1 or 2, wherein the thermoelectrical element is configured for providing a subject's body temperature at the target portion above the natural subject's body core temperature of 37°C, preferably an absolute temperature of about 44 °C to 48 °C, and/or a subject's body temperature at the target portion below the natural subject's body core temperature of 37°C, preferably an absolute temperature of about 10 °C to 30 °C.

33 The ear device of any one of the preceding claims, wherein the contact portion is selffitting, optionally wherein the contact portion is self-expanding. The ear device of any one of the preceding claims, wherein the earcanal piece comprises a portion configured for being located at the isthmus of the ear canal, wherein an uncompressed maximum width of this portion is configured to be equal to or smaller than the narrowest width of the ear canal at the isthmus; or wherein the earcanal piece comprises a portion configured for being located at the isthmus of the ear canal, wherein the portion is configured to be collapsible to a minimum width that is equal to or smaller than the narrowest width of the ear canal at the isthmus. The ear device of any one of the preceding claims, wherein the contact portion has a cone shape, a truncated cone shape, a spherical shape, a truncated spherical shape, a cylindrical shape, or a cylindrical shape with a cone shaped end. The ear device of any one of the preceding claims, wherein the contact portion is collapsible from the expanded state to the collapsed state for and/or upon passing the second turn and/or the isthmus of the ear canal. The ear device of any one of claims 1-7, wherein the thermoelectrical element is configured to be located exterior to the ear canal, wherein the thermoelectrical element is thermally coupled to the contact portion and/or the contact surface via a thermal conduit, the thermal conduit having a high thermal conductivity identical or different from the thermal conductivity of the contact surface and configured for transporting thermal energy between the contact portion and the thermoelectrical element. The ear device of any one of the preceding claims, wherein the contact portion comprises a sponge and/or fabric structure, preferably made from metal, silicone, polyester and/or polyamine. The ear device of any one of the preceding claims, configured for warming and/or cooling for at least 5 min, preferably at least 10 min, more preferably at least 20 min, more preferably at least 30 min, more preferably at least 60 min, most preferably at least 90 min. A system for inducing temperature changes in the inner ear and/or labyrinth of a subject, comprising a controller; and a first ear device according to any one of the preceding claims, the first ear device being operatively connected to the controller; wherein the controller is configured for controlling the first ear device. The system of the previous claim, further comprising a second ear device according to any one of claims 1-10, the second ear device being operatively connected to the controller, wherein the controller is configured for controlling the second ear device.

34 The system according to the previous claim, wherein the earcanal piece of the first ear device is configured for at least partial insertion into a first ear canal of a subject and the earcanal piece of the second ear device is configured for at least partial insertion into the second ear canal of the subject; wherein the earcanal pieces of the first and second ear devices are configured to cool and/or heat a posterior surface of the first and second ear canals of the subject proximate the ear drum, respectively; and wherein the controller is configured to control the ear devices according to the following steps a)-g) in this order: a) warming of the first ear canal of the subject, preferably for a period of 15-120 s; b) stopping the warming step a) and pausing, preferably for at least 2 min, more preferably at least 5 min, most preferably 10 min; c) warming of the second ear canal of the subject, preferably for a period of 15-120 s; d) stopping the warming step c) and pausing, preferably for at least 2min, more preferably at least 5min, most preferably 10 min; e) cooling one of the first and second ear canals, preferably for 15-120 s; f) stopping the cooling step e) and pausing, preferably for 2 min, more preferably at least 5 min, most preferably 10 min; cooling the other one of the first and second ear canals, preferably for 15-120 s; and/or wherein the controller is configured to control the ear devices according to the following steps a)-d) in this order: a) warming of the first ear canal and simultaneous cooling of the second ear canal of the subject, preferably for a period of 15-120 s; b) stopping the warming and cooling step a) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min; c) warming of the second ear canal and simultaneous cooling of the first ear canal of the subject, preferably for a period of 15-120 s; d) stopping the warming and cooling step c) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min; and/or wherein the controller is configured to control the ear devices according to the following steps a)-d) in this order: a) simultaneous warming of the first ear canal and the second ear canal of the subject, preferably for a period of 15-120 s; b) stopping the warming step a) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min; c) simultaneous cooling of the first and second ear canals of the subject, preferably for a period of 15-120 s; d) stopping the cooling step c) and pausing, preferably for at least 2 minutes, more preferably at least 5 min, most preferably at least 10 min; wherein for all steps the subject is preferably in supine position with an elevated head, preferably at 10°-50°, more preferably 20°-40°, most preferably 30°, as measured relative to a horizontal line. The system according to any one of claims 11, 12 or 13, wherein the controller is operably connected to an eye-tracking system, preferably eye tracking goggles, more preferably video-oculargraphy goggles and/or virtual reality goggles; and wherein the eye tracking system is configured to record eye movement of the subject during stimulation and optionally at least 120 s after the warming steps and/or the cooling steps, wherein the system is optionally configured to determine nystagmus and to adapt the steps upon determination of robust nystagmus, for example wherein the system is configured to stop an ongoing warming and/or cooling upon determination of robust nystagmus and to proceed with the next step. The ear device or system according to any one of the preceding claims, wherein the earcanal piece accommodates the angled anatomy of the ear canal.