U.S. patent application number 12/168636 was filed with the patent office on 2009-10-01 for transcutaneous magnetic bone conduction device.
This patent application is currently assigned to COCHLEAR LIMITED. Invention is credited to John Parker.
Application Number | 20090248155 12/168636 |
Document ID | / |
Family ID | 41117259 |
Filed Date | 2009-10-01 |
United States Patent
Application |
20090248155 |
Kind Code |
A1 |
Parker; John |
October 1, 2009 |
TRANSCUTANEOUS MAGNETIC BONE CONDUCTION DEVICE
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.
Inventors: |
Parker; John; (Roseville,
AU) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ LLP
1875 EYE STREET, N.W., SUITE 1100
WASHINGTON
DC
20006
US
|
Assignee: |
COCHLEAR LIMITED
Lane Cove
AU
|
Family ID: |
41117259 |
Appl. No.: |
12/168636 |
Filed: |
July 7, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61041185 |
Mar 31, 2008 |
|
|
|
Current U.S.
Class: |
623/10 ;
381/326 |
Current CPC
Class: |
A61M 2210/0662 20130101;
H04R 25/00 20130101; H04R 25/70 20130101; Y10T 29/49572 20150115;
A61M 2205/05 20130101; H04R 2460/13 20130101; H04R 25/606 20130101;
A61M 5/14276 20130101 |
Class at
Publication: |
623/10 ;
381/326 |
International
Class: |
A61F 2/18 20060101
A61F002/18; H04R 25/00 20060101 H04R025/00 |
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.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] 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
[0002] 1. Field of the Invention
[0003] The present invention is generally directed to a bone
conduction device, and more particularly, to a transcutaneous
magnetic bone conduction device
[0004] 2. Related Art
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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).
[0010] 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.
[0011] 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
[0012] 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.
[0013] 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.
[0014] 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
[0015] Illustrative embodiments of the present invention are
described herein with reference to the accompanying drawings, in
which:
[0016] FIG. 1 is a perspective view of a transcutaneous bone
conduction provided to a recipient according to one embodiment of
the present invention;
[0017] 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;
[0018] FIG. 2B is a detailed functional block diagram of the
transcutaneous bone conduction device illustrated in FIG. 2A;
[0019] 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;
[0020] FIG. 4 is a perspective view of a transcutaneous bone
conduction device according to a further embodiment of the present
invention;
[0021] FIG. 5A is a perspective side view of a transcutaneous bone
conduction device according to another embodiment of the present
invention;
[0022] FIG. 5B is an isometric view of the device shown in FIG.
5A;
[0023] FIG. 5C is a cross-sectional view of the device of FIG.
5B;
[0024] FIG. 6 is a perspective side view of a transcutaneous bone
conduction device according to yet another embodiment of the
present invention; and
[0025] FIG. 7 is a perspective side view of a transcutaneous bone
conduction device according to a further embodiment of the present
invention.
DETAILED DESCRIPTION
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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.
[0036] 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.
[0037] 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.
[0038] 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.
[0039] 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.
[0040] 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.
[0041] 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).
[0042] 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.
[0043] 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.
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] 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.
[0059] 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.
[0060] 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.
[0061] 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).
[0062] 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.
[0063] 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.
[0064] 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.
[0065] 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.
[0066] 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.
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