US20090248155A1

US20090248155A1 - Transcutaneous magnetic bone conduction device

Info

Publication number: US20090248155A1
Application number: US12/168,636
Authority: US
Inventors: John Parker
Original assignee: Cochlear Ltd
Current assignee: Cochlear Ltd
Priority date: 2008-03-31
Filing date: 2008-07-07
Publication date: 2009-10-01
Also published as: US8154173B2; EP2269386A4; WO2009121115A9; US9602931B2; US20090248023A1; WO2009124038A1; US20090247811A1; US8433081B2; US20090247814A1; WO2009124036A3; WO2009121115A1; WO2009121114A9; WO2009121111A1; EP2272260A4; US8216287B2; US20090245554A1; US8731205B2; WO2009121118A9; WO2009124010A3; US20090247810A1

Abstract

A bone conduction device for enhancing the hearing of a recipient, comprising: a sound input element configured to receive an acoustic sound signal; an electronics module configured generate an electrical signal representing the acoustic sound signal; a transducer configured to generate mechanical forces representing the electrical signal for deliver to the recipient's skull; one or more external components mechanically coupled to the transducer and configured to transfer the mechanical forces; and one or more implanted components magnetically coupled to the one or more external components and configured to receive the mechanical forces from the external components.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Patent Application 61/041,185; filed Mar. 31, 2008, which is hereby incorporated by reference herein.

BACKGROUND

1. Field of the Invention
The present invention is generally directed to a bone conduction device, and more particularly, to a transcutaneous magnetic bone conduction device
2. Related Art
Hearing loss, which may be due to many different causes, is generally of two types, conductive or sensorineural. In many people who are profoundly deaf, the reason for their deafness is sensorineural hearing loss. This type of hearing loss is due to absence, destruction, or damage to the hairs that transduce acoustic signals into nerve impulses in the cochlea. Various prosthetic hearing implants have been developed to provide individuals who suffer from sensorineural hearing loss with the ability to perceive sound. One type of prosthetic implant, referred to as a cochlear implant, uses an electrode array implanted in the cochlea. More specifically, an electrical stimulus is provided via the electrode array directly to the cochlea nerve, thereby inducing a hearing sensation in the implant recipient.
Conductive hearing loss occurs when the normal mechanical pathways, which conduct sound to hairs in the cochlea, are impeded. This problem may arise from damage to the ossicular chain to ear canal. However, individuals who suffer from conductive hearing loss frequently still have some form of residual hearing because the hairs in the cochlea are often undamaged. For this reason, individuals who suffer from conductive hearing loss are typically not candidates for a cochlear implant, because insertion of the electrode array into a cochlea may result in the severe damage or destruction of the most of the hair cells within the cochlea.
Sufferers of conductive hearing loss typically receive an acoustic hearing aid. Hearing aids receive ambient sound in the outer ear, amplify the sound, and direct the amplified sound into the ear canal. The amplified sound reaches the cochlea and causes motion of the cochlea fluid, thereby stimulating the hairs in the cochlea.
An alternative to a normal air conduction aid is a bone conduction hearing aid which incorporates a hearing aid which drives a vibrator which is pushed against the skull via a mechanism. Such mechanisms include glasses and wire hoops. These devices are uncomfortable to wear and for some recipients are incapable of producing sufficient gain.
Unfortunately, hearing aids do not benefit all individuals who suffer from conductive hearing loss. For example, some individuals are prone to chronic inflammation or infection of the ear canal and cannot wear hearing aids. Other individuals have malformed or absent outer ear and/or ear canals as a result of a birth defect, or as a result of common medical conditions such as Treacher Collins syndrome or Microtia. Hearing aids are also typically unsuitable for individuals who suffer from single-sided deafness (i.e., total hearing loss only in one ear) or individuals who suffer from mixed hearing losses (i.e., combinations of sensorineural and conductive hearing loss).
Those individuals who cannot benefit from hearing aids may benefit from hearing prostheses that are implanted into the skull bone. Such hearing prostheses direct vibrations into the bone, so that the vibrations are conducted into the cochlea and result in stimulation of the hairs in the cochlea. This type of prosthesis is typically referred to as a bone conduction device.
Bone conduction devices function by converting a received sound into a mechanical vibration representative of the received sound. This vibration is then transferred to the bone structure of the skull, causing vibration of the recipient's skull and serves to stimulate the cochlea hairs, thereby inducing a hearing sensation in the recipient.

SUMMARY

According to one aspect of the present invention, there is provided a bone conduction device for enhancing the hearing of a recipient, comprising: a sound input element configured to receive an acoustic sound signal; an electronics module configured generate an electrical signal representing the acoustic sound signal; a transducer configured to generate mechanical forces representing the electrical signal for deliver to the recipient's skull; one or more external components mechanically coupled to the transducer and configured to transfer the mechanical forces; and one or more implanted components magnetically coupled to the one or more external components and configured to receive the mechanical forces from the external components.
According to another aspect of the present invention, there is provided a method for rehabilitating the hearing of a recipient with a bone conduction device having one or more external components and one or more implanted components, comprising: receiving an electrical signal representative of an acoustic sound signal; generating mechanical forces representative of the received electrical signal; forming a magnetic coupling between the bone conduction device and the recipient's skull; and delivering the mechanical forces to the recipient's skull via the magnetic coupling.
According to yet another aspect of the present invention, there is provided a bone conduction device for enhancing the hearing of a recipient having one or more external components and one or more implanted components, comprising: means for receiving an electrical signal representative of an acoustic sound signal; means for generating mechanical forces representative of the received electrical signal; means for forming a magnetic coupling between the bone conduction device and the recipient's skull; and means for delivering the mechanical forces to the recipient's skull via the magnetic coupling.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present invention are described herein with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a transcutaneous bone conduction provided to a recipient according to one embodiment of the present invention;

FIG. 2A is a high-level functional block diagram of a transcutaneous bone conduction device according to one embodiment of the present invention, such as the device of FIG. 1;

FIG. 2B is a detailed functional block diagram of the transcutaneous bone conduction device illustrated in FIG. 2A;

FIG. 3 is a flowchart illustrating the conversion of an input sound into skull vibration in a transcutaneous bone conduction device according to one embodiment of the present invention;

FIG. 4 is a perspective view of a transcutaneous bone conduction device according to a further embodiment of the present invention;

FIG. 5A is a perspective side view of a transcutaneous bone conduction device according to another embodiment of the present invention;

FIG. 5B is an isometric view of the device shown in FIG. 5A;

FIG. 5C is a cross-sectional view of the device of FIG. 5B;

FIG. 6 is a perspective side view of a transcutaneous bone conduction device according to yet another embodiment of the present invention; and

FIG. 7 is a perspective side view of a transcutaneous bone conduction device according to a further embodiment of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention are generally directed to a bone conduction device for converting a received acoustic sound signal into a mechanical force delivered transcutaneously via a recipient's skull to the recipient's hearing organs. The bone conduction device includes a sound input component, such as microphone, to receive the acoustic sound signal, an electronics module configured to generate an electrical signal representing the acoustic sound signal, and a piezoelectric transducer to convert the electrical signal into a mechanical force for delivery to the recipient's skull. In certain embodiments of the present invention, the transducer is connected to one or several magnets or metal components which are magnetically coupled to magnets implanted between the recipient's bone and skin. In other embodiments of the present invention, one or several metal components, which are connected to the transducer, are magnetically coupled to corresponding magnets that are implanted between the recipient's bone and skin. The magnets or metal components connected to the transducer are connected such that force generated by the transducer is mechanically communicated to the connected magnets or metal components, which in turn magnetically communicate the generate force or portions thereof to the implanted one or several magnets or metal components. The piezoelectric transducer has a piezoelectric element that deforms in response to application of the electrical signal thereto. The transducer has an output stroke that exceeds the deformation of the piezoelectric element.
The output stroke of the transducer (sometimes referred to herein as the “transducer stroke”) is utilized to generate a mechanical force that may be provided to the recipient's skull. The sound perceived by a recipient is dependent, in part, upon the magnitude of mechanical force generated by the transducer. In some bone conduction devices, the magnitude of the mechanical force may be limited by the available transducer stroke. These limitations may cause distortion in the sound signal perceived by the recipient or limit the population of recipient's that may benefit from the device. For example, in certain embodiments, limited transducer stroke results in insufficient gain to adequately represent a received acoustic sound signal for all individuals. This insufficient gain may cause a signal to be clipped or otherwise distorted.
As noted, the piezoelectric transducer comprises a piezoelectric element. The piezoelectric element converts an electrical signal applied thereto into a mechanical deformation (i.e. expansion or contraction) of the element. The amount of deformation of a piezoelectric element in response to an applied electrical signal depends on material properties of the element, orientation of the electric field with respect to the polarization direction of the element, geometry of the element, etc.
The deformation of the piezoelectric element may also be characterized by the free stroke and blocked force of the element. The free stroke of a piezoelectric element refers to the magnitude of deformation induced in the element when a given voltage is applied thereto. Blocked force refers to the force that must be applied to the piezoelectric element to stop all deformation at the given voltage. Generally speaking, piezoelectric elements have a high blocked force, but a low free stroke. In other words, when a voltage is applied to the element, the element will can output a high force, but will only a small stroke.
As noted, bone conduction devices generate a mechanical force that is delivered to the skull, thereby causing motion of the cochlea fluid and a hearing perception by the recipient. In some piezoelectric transducers, the maximum available transducer stroke is equivalent to the free stroke of the piezoelectric element. As such, some bone conduction devices utilizing these types of piezoelectric transducer have a limited transducer stroke and corresponding limits on the magnitude of the mechanical force that may be provided to the skull.
FIG. 1 is a perspective view of embodiments of a bone conduction device 100 in which embodiments of the present invention may be advantageously implemented. In a fully functional human hearing anatomy, outer ear 105 comprises an auricle 105 and an ear canal 106. A sound wave or acoustic pressure 107 is collected by auricle 105 and channeled into and through ear canal 106. Disposed across the distal end of ear canal 106 is a tympanic membrane 104 which vibrates in response to acoustic wave 107. This vibration is coupled to oval window or fenestra ovalis 110 through three bones of middle ear 102, collectively referred to as the ossicles 111 and comprising the malleus 112, the incus 113 and the stapes 114. Bones 112, 113 and 114 of middle ear 102 serve to filter and amplify acoustic wave 107, causing oval window 110 to articulate, or vibrate. Such vibration sets up waves of fluid motion within cochlea 115. Such fluid motion, in turn, activates tiny hair cells (not shown) that line the inside of cochlea 115. Activation of the hair cells causes appropriate nerve impulses to be transferred through the spiral ganglion cells and auditory nerve 116 to the brain (not shown), where they are perceived as sound.
FIG. 1 also illustrates the positioning of bone conduction device 100 relative to outer ear 101, middle ear 102 and inner ear 103 of a recipient of device 100. As shown, bone conduction device 100 may be positioned behind outer ear 101 of the recipient.
In the embodiments illustrated in FIG. 1, bone conduction device 100 comprises a housing 125 having a microphone (not shown) positioned therein or thereon. Housing 125 is coupled to the body of the recipient via coupling 140 and implanted magnet 162. As described below, bone conduction device 100 may comprise a sound processor, a transducer, transducer drive components and/or various other electronic circuits/devices.
In accordance with embodiments of the present invention, an anchor system (not shown) may be implanted in the recipient. As described below, the anchor system may be fixed to bone 136. In various embodiments, the anchor system may be implanted under skin 132 within muscle 134 and/or fat 128. In certain embodiments, a coupling 140 attaches device 100 to the anchor system.
A functional block diagram of one embodiment of bone conduction 100, referred to as bone conduction device 200, is shown in FIG. 2A. In the illustrated embodiment, a sound 207 is received by a sound input element 202. In some embodiments, sound input element 202 is a microphone configured to receive sound 207, and to convert sound 207 into an electrical signal 222. As described below, in other embodiments sound 207 may received by sound input element 202 as an electrical signal.
As shown in FIG. 2A, electrical signal 222 is output by sound input element 202 to an electronics module 204. Electronics module 204 is configured to convert electrical signal 222 into an adjusted electrical signal 224. As described below in more detail, electronics module 204 may include a sound processor, control electronics, transducer drive components, and a variety of other elements.
As shown in FIG. 2A, transducer 206 receives adjusted electrical signal 224 and generates a mechanical output force that is delivered to the skull of the recipient via coupling 140, shown in FIG. 2A as anchor system 208, that is coupled to bone conduction device 200. Delivery of this output force causes one or more of motion or vibration of the recipient's skull, thereby activating the hair cells in the cochlea via cochlea fluid motion.
FIG. 2A also illustrates a power module 210. Power module 210 provides electrical power to one or more components of bone conduction device 200. For ease of illustration, power module 210 has been shown connected only to interface module 212 and electronics module 204. However, it should be appreciated that power module 210 may be used to supply power to any electrically powered circuits/components of bone conduction device 200.
Bone conduction device 200 further includes an interface module 212 that allows the recipient to interact with device 200. For example, interface module 212 may allow the recipient to adjust the volume, alter the speech processing strategies, power on/off the device, etc. Interface module 212 communicates with electronics module 204 via signal line 228.
In the embodiment illustrated in FIG. 2A, sound pickup device 202, electronics module 204, transducer 206, power module 210 and interface module 212 have all been shown as integrated in a single housing, referred to as housing 225. However, it should be appreciated that in certain embodiments of the present invention, one or more of the illustrated components may be housed in separate or different housings. Similarly, it should also be appreciated that in such embodiments, direct connections between the various modules and devices are not necessary and that the components may communicate, for example, via wireless connections.
In embodiments of the present invention, transducer 206 may be one of many types and configurations of transducers, now known or later developed. In one embodiment of the present invention, transducer 206 may comprise a piezoelectric element which is configured to deform in response to the application of electrical signal 224. Piezoelectric elements that may be used in embodiments of the present invention may comprise, for example, piezoelectric crystals, piezoelectric ceramics, or some other material exhibiting a deformation in response to an applied electrical signal. Exemplary piezoelectric crystals include quartz (SiO2), Berlinite (AlPO4), Gallium orthophosphate (GaPO4) and Tourmaline. Exemplary piezoelectric ceramics include barium titanate (BaTiO30), lead zirconium titanate (PZT), or zirconium (Zr).
Some piezoelectric materials, such as lead zircoium titanate and PZT, are polarized materials. When an electric field is applied across these materials, the polarized molecules align themselves with the electric field, resulting in induced dipoles within the molecular or crystal structure of the material. This alignment of molecules causes the deformation of the material.
In other embodiments of the present invention, other types of transducers may be used. For example, various motors configured to operate in response to electrical signal 224 may be used.
In one embodiment of the present invention, transducer 206 generates an output force that causes movement of the cochlea fluid so that a sound may be perceived by the recipient. The output force may result in mechanical vibration of the recipient's skull, or in physical movement of the skull about the neck of the recipient. As noted above, in certain embodiments, bone conduction device 300 delivers the output force to the skull of the recipient via an anchor system 208. In one embodiment of the present invention, anchor system 208 comprises one or more external magnets 260 which magnetically couples to one or more implanted magnets 262, as illustrated in FIG. 2B. In the embodiment illustrated in FIG. 2A, external magnets 260 are configured to be attached to housing 225. As such, in this embodiment, vibration from transducer 206 is provided to external magnets 260 through housing 225.
In certain embodiments of the present invention, electronics module 204 includes a printed circuit board (PCB) to electrically connect and mechanically support the components of electronics module 204. Sound input element 202 may comprise one or more microphones (not shown) and is attached to the PCB.
FIG. 2B provides a more detailed view of bone conduction device 200 of FIG. 2A. In the illustrated embodiment, electronics module 204 comprises a sound processor 240, transducer drive components 242 and control electronics 246. As explained above, in certain embodiments sound input element 202 comprises a microphone configured to convert a received acoustic signal into electrical signal 222. In other embodiments, as detailed below, sound input element 202 receives sound 207 as an electrical signal.
In embodiments of the present invention, electrical signal 222 is output from sound input element 202 to sound processor 240. Sound processor 240 uses one or more of a plurality of techniques to selectively process, amplify and/or filter electrical signal 222 to generate a processed signal 224A. In certain embodiments, sound processor 240 may comprise substantially the same sound processor as is used in an air conduction hearing aid. In further embodiments, sound processor 240 comprises a digital signal processor.
Processed signal 224A is provided to transducer drive components 242. Transducer drive components 242 output a drive signal 224B, to transducer 206. Based on drive signal 224B, transducer 206 provides the output force to the skull of the recipient.
For ease of description the electrical signal supplied by transducer drive components 242 to transducer 206 has been referred to as drive signal 224B. However, it should be appreciated that processed signal 224B may comprise an unmodified version of processed signal 224A.
As noted above, transducer 206 generates an output force to the skull of the recipient via anchor system 208. As shown in FIG. 2B, in one embodiment of the present invention, anchor system 208 comprises an external magnet 260 which magnetically couples to an implanted magnet 262. External magnet 260 may be attached to one or more of transducer 206 or housing 225. For example, in certain embodiments, external magnet 260 is attached to transducer 206 and vibration is received directly therefrom. In other embodiments, external magnet 260 is attached to housing 225 and vibration is applied from transducer 206 through housing 225 to external magnet 260. According to one embodiment of the present invention in which coupling 140 comprises external magnet 260, the vibration received by external magnet 260 from transducer 206 causes external magnet 260 to vibrate. Since, according to this embodiment of the present invention, external magnet 260 is magnetically coupled to implanted magnet 262, the magnetic forces coupling external magnet 260 and implanted magnet 262 vibrates accordingly. The vibration, communicated from external magnet 260 to implanted magnet 262 magnetically, is then transferred from implanted magnet 262 to the recipient's bone 136.
As noted above, a recipient may control various functions of the device via interface module 212. Interface module 212 includes one or more components that allow the recipient to provide inputs to, or receive information from, elements of bone conduction device 200.
As shown, control electronics 246 may be connected to one or more of interface module 212, sound pickup device 202, sound processor 240 and/or transducer drive components 242. In embodiments of the present invention, based on inputs received at interface module 212, control electronics 246 may provide instructions to, or request information from, other components of bone conduction device 200. In certain embodiments, in the absence of user inputs, control electronics 246 control the operation of bone conduction device 200.
FIG. 3 illustrates the conversion of an input acoustic sound signal into a mechanical force for delivery to the recipient's skull in accordance with embodiments of bone conduction device 200. At block 302, bone conduction device 200 receives an acoustic sound signal. In certain embodiments, the acoustic sound signal is received via microphones. In other embodiments, the input sound is received via an electrical input. In still other embodiments, a telecoil integrated in, or connected to, bone conduction device 200 may be used to receive the acoustic sound signal.
At block 304, the acoustic sound signal received by bone conduction device 200 is processed by the speech processor in electronics module 204. As explained above, the speech processor may be similar to speech processors used in acoustic hearing aids. In such embodiments, speech processor may selectively amplify, filter and/or modify acoustic sound signal. For example, speech processor may be used to eliminate background or other unwanted noise signals received by bone conduction device 200.
At block 306, the processed sound signal is provided to transducer 206 as an electrical signal. At block 308, transducer 206 converts the electrical signal into a mechanical force configured to be delivered to the recipient's skull via anchor system 208 so as to illicit a hearing perception of the acoustic sound signal.
FIG. 4 illustrates one embodiment of the present invention in which anchor system 208 comprises a single external magnet 408. External magnet 408 magnetically couples with implanted magnet 462 and delivers the mechanical force 470 from transducer module 406 to the recipient's skull 136. As will be appreciated by persons having skill in the art, implanted magnet 462 is attached to recipient's skull 136 in a variety of ways. For example, implanted magnet 462 may be bonded to recipient's skull 136 using one or more adhesive compounds. Also, for example, implanted magnet 462 may be attached by bonding or other means to an osseointegrative mesh or other structure which is configured to integrate with the recipient's skull bone over a period of time. Furthermore, in other embodiments of the present invention, implanted magnet 462 may be sutured into place, where the suture provides an interference pressure upon implanted magnet 462 against the recipient's skull. Alternatively, implanted magnet 462 may have structural features which are designed or may additionally be used by a suture to hold implanted magnet 462 against the recipient's skull. It is also to be understood that as implanted magnet 462 is positioned between the recipient's tissue 132, 128, 134 and the recipient's skull 136, the compression between the recipient's tissue and skull may be the primary mechanism used to keep implanted magnet 162 is a fixed position.
Also, it is to be understood that in certain embodiments of the present invention, recipient's skull may be modified (not shown) to create a bed sized according to the circumferential dimensions of implanted magnet 462, where the bed has a depth to at least partially or completely receive the full thickness of implanted magnet 462. Additionally, as will be described later in conjunction with the embodiment illustrated in FIG. 7, implanted magnet 462 may be bonded or otherwise attached to a plate which is itself attached to recipient's bone using, for example, screws which enter recipient's bone to fix the plate to the bone. Although FIG. 4 illustrates speech processor 404 as being in a separate housing from transducer 406, it is to be understood that transducer 406 and speech processor 404 may be housed in a single housing such as housing 125 as illustrated in FIG. 1.
In FIG. 4, mechanical force 470 is produced by transducer 406 as a force that is directed in a perpendicular manner with respect to recipient's skull 136. However, it is to be understood that in other embodiments of the present invention, mechanical force 470 may be produced by transducer 406 in a non-perpendicular manner, for example, parallel to the surface of recipient's bone 136. It should be understood that the various directions or projections of mechanical forces generated and delivered via the magnetic coupling described above to recipient's bone 136 are considered a part of the present invention.
FIG. 5A illustrates another embodiment of the bone conduction device 100 of FIG. 1, referred to as bone conduction device 500. In this embodiment, two external magnets 508A and 508B (referred to collectively as external magnets 508) are attached to housing 525. In this embodiment of the present invention, the transducer module (not shown) in housing 525 generates a mechanical force which is transferred via housing 525 to external magnets 508. External magnets 508 are magnetically coupled to implanted magnets 562A and 562B (referred to collectively as implanted magnets 562). As illustrated in FIG. 5A, perpendicular force 570A is transmitted from external magnet 508A to implanted magnet 562A and perpendicular force 570B is transmitted from external magnet 508B to implanted magnet 562B. Implanted magnets 562 in turn transmit the received perpendicular force to recipient's skull 136 in a manner as described above. Implanted magnets 562 may be attached to or bonded to recipient's skull 136 as described above in conjunction with FIG. 4.
Although FIGS. 5A, 5B and 5C depict bone conduction device 500 as having two external and implanted magnets 508, 562, it is to be understood that device 500 may comprise a larger number or configuration of magnets. Furthermore, it is to be understood that implanted magnets 562 may be attached to one another such that only a subset of implanted magnets 562 may be fixed to recipient's skull 136 in such a way that the fixed implant magnet provides fixation for the other implanted magnets 562. Similarly, it is to be understood that in other embodiments of the present invention, external magnets 508 may be attached or otherwise connected to each other, for example on a shared plate or base which is itself attached or coupled to transducer 525.
FIG. 5B shows a perspective view of one embodiment of the present invention, demonstrating one configuration in which external magnets 508 are arranged to magnetically couple to implanted magnets (not shown). A cross-section of FIG. 5B is shown as FIG. 5C, which also illustrates external magnets 508 and housing 525. In the embodiment illustrated in FIGS. 5B and 5C, the various other components of bone conduction device 500 is contained in housing 525, including the transducer which transmits mechanical force to housing 525 such that external magnets 508 receives and transmits that force to implant magnets (not shown).
FIG. 6 illustrates another embodiment of the bone conduction device 500 of FIG. 5A, referred to as bone conduction device 600. As in the embodiment illustrated in FIG. 5A, in this embodiment, two external magnets 608A and 608B (referred to collectively as external magnets 608) are attached to housing 625. In this embodiment of the present invention, the transducer module (not shown) in housing 625 generates a mechanical force substantially parallel to the surface of recipient's skull 136 which is transferred via housing 625 to external magnets 608. External magnets 608 are magnetically coupled to implanted magnets 662A and 662B (referred to collectively as implanted magnets 662). As illustrated in FIG. 6, parallel force 670A is transmitted from external magnet 608A to implanted magnet 662A, and parallel force 670B is transmitted from external magnet 608B to implanted magnet 662B. Implanted magnets 662 in turn transmit the received parallel force to recipient's skull 136 in a manner as described above.
As noted previously, according to embodiments of the present invention, the implanted magnets may be fixed to the recipient's skull in various ways. For example, in the embodiment illustrated in FIG. 7, bone conduction device 700 comprises housing 725 comprising a transducer (not shown) among other device components. External magnets 708A and 708B (collectively referred to as external magnets 708) are attached to housing 725 and receive the mechanical forces generated by transducer via the surface of housing 725. External magnets 708 are magnetically coupled to implanted magnets 762A and 672B collectively referred to as implanted magnets 762) and transmit the mechanical forces received to implant magnets 762 as magnetic forces 770A and 770B (collectively referred to as magnetic forces 770). In the illustrated embodiment, the forces generated by the transducer (not shown) in housing 725 are directed in parallel with respect to the surface of the recipient's skull 136. Therefore, external magnets 708 are caused to correspondingly move in parallel to the recipient's skull, which results in the magnetic forces 770 moving in parallel with respect to recipient's skull 136.
Implanted magnets 762 are attached to plate 780, which is fixed to recipient's skull 136 using fixation screws 782A and 782B (collectively referred to as screws 782). In the embodiment illustrated in FIG. 7, even though magnetic forces 770 are directed only to implanted magnets 762 and not to plate 780, because implanted magnets 762 are attached to plate 780, magnetic forces 770 are transferred from implanted magnets 762 to plate 780 and then to recipient's skull 136.
Although embodiments of the present invention have been described above where the one or more external magnets couple to one or more implanted magnets, it is to be understood that an iron-based metal may be used in place of either the external or implanted magnets so long as the magnetic coupling between the magnet and metal is of sufficient strength to enable adequate transfer of the mechanical forces generated by the transducer.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. All patents and publications discussed herein are incorporated in their entirety by reference thereto.

Claims

1. A bone conduction device for enhancing the hearing of a recipient, comprising:

a sound input element configured to receive an acoustic sound signal;

an electronics module configured generate an electrical signal representing said acoustic sound signal;

a transducer configured to generate mechanical forces representing said electrical signal for deliver to the recipient's skull;

one or more external components mechanically coupled to said transducer and configured to transfer said mechanical forces; and

one or more implanted components magnetically coupled to said one or more external components and configured to receive said mechanical forces from said external components.

2. The device of claim 1, wherein said external components and said implanted components each comprise magnets.

3. The device of claim 1, wherein said only one of said external components and said implanted components comprise magnets.

4. The device of claim 1, wherein each of said one or more implanted component is configured to be inserted into the recipient's skull in one or more corresponding beds formed in the skull and configured to accommodate said implanted components.

5. The device of claim 1, wherein said one or more implanted components are fixedly attached to the recipient's skull.

6. The device of claim 5, wherein said one or more implanted components are bonded to the recipient's skull.

7. The device of claim 5, wherein said one or more implanted components are attached to one or more plates fixed to the recipient's skull.

8. The device of claim 5, wherein said one or more implanted components are fixed by one or more screws to the recipient's skull.

9. The device of claim 5, wherein said one or more implanted components are fixed to an osseointegrative mesh which is configured to integrate with the recipient's skull.

10. The device of claim 1, wherein said mechanical force is generated by said transducer in parallel with respect to the surface of the recipient's skull.

11. The device of claim 1, wherein said mechanical force is generated by said transducer perpendicular to the surface of the recipient's skull.

12. A method for rehabilitating the hearing of a recipient with a bone conduction device having one or more external components and one or more implanted components, comprising:

receiving an electrical signal representative of an acoustic sound signal;

generating mechanical forces representative of the received electrical signal;

forming a magnetic coupling between the bone conduction device and the recipient's skull; and

delivering said mechanical forces to the recipient's skull via the magnetic coupling.

13. The method of claim 12, wherein the magnetic coupling is formed using one or more implanted magnets.

14. The method of claim 12, wherein the magnetic coupling is formed using one or more external magnets.

15. The method of claim 12, further comprising:

forming a bed in the recipient's skull in which the implanted components are configured to be positioned.

16. The method of claim 12, further comprising:

attaching the one or more implanted components to the recipient's skull.

17. The method of claim 16, wherein said one or more implanted components are attached by bonding to the recipient's skull.

18. The method of claim 16, wherein said one or more implanted components are attached to one or more plates fixed to the recipient's skull.

19. The method of claim 16, wherein said one or more implanted components are attached by one or more screws to the recipient's skull.

20. The method of claim 16, wherein said one or more implanted components are fixed to an osseointegrative mesh which is configured to attach to recipient's skull by osseointegration over time.

21. A bone conduction device for enhancing the hearing of a recipient having one or more external components and one or more implanted components, comprising:

means for receiving an electrical signal representative of an acoustic sound signal;

means for generating mechanical forces representative of the received electrical signal;

means for forming a magnetic coupling between the bone conduction device and the recipient's skull; and

means for delivering said mechanical forces to the recipient's skull via the magnetic coupling.

22. The method of claim 21, further comprising:

means for receiving the implanted components in the recipient's skull.

23. The method of claim 21, further comprising:

means for attaching the one or more implanted components to the recipient's skull.