U.S. patent application number 15/161750 was filed with the patent office on 2016-12-29 for magnetic retention device.
The applicant listed for this patent is Johan GUSTAFSSON. Invention is credited to Johan GUSTAFSSON.
Application Number | 20160381473 15/161750 |
Document ID | / |
Family ID | 57584817 |
Filed Date | 2016-12-29 |
United States Patent
Application |
20160381473 |
Kind Code |
A1 |
GUSTAFSSON; Johan |
December 29, 2016 |
MAGNETIC RETENTION DEVICE
Abstract
An apparatus, including an external component of a medical
device configured to generate a magnetic flux that removably
retains, via a resulting magnetic retention force, the external
component to a recipient thereof, wherein the external component is
configured to enable the adjustment of a path of the generated
magnetic flux so as to vary the resulting magnetic retention
force.
Inventors: |
GUSTAFSSON; Johan;
(Molnlycke, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GUSTAFSSON; Johan |
Molnlycke |
|
SE |
|
|
Family ID: |
57584817 |
Appl. No.: |
15/161750 |
Filed: |
May 23, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62185288 |
Jun 26, 2015 |
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Current U.S.
Class: |
600/25 |
Current CPC
Class: |
H04R 25/606 20130101;
A61F 2250/0001 20130101; H04R 2460/13 20130101; H01F 7/0242
20130101; H01F 7/04 20130101; H04R 2225/67 20130101 |
International
Class: |
H04R 25/00 20060101
H04R025/00 |
Claims
1. An apparatus, comprising: an external component of a medical
device; and an implantable component of the medical device, wherein
the apparatus is configured to generate a magnetic flux that
removably retains, via a resulting magnetic retention force, the
external component to a recipient thereof, wherein the external
apparatus is configured to enable the adjustment of a path of the
generated magnetic flux so as to vary the resulting magnetic
retention force.
2. The apparatus of claim 1, wherein: the external component is
configured to enable adjustment of the path of the generated
magnetic flux, wherein adjustment of the path is relative to a
global orientation of the external component.
3. The apparatus of claim 1, wherein: the external component
includes a skin interface surface; the adjustment of the path is
relative to a direction normal to the skin interface surface.
4. The apparatus of claim 1, wherein: the external component
includes a permanent magnet that generates at least a portion of
the generated magnetic flux; and the external component is
configured to enable tilting of the permanent magnet, thereby
adjusting the path of the generated magnetic flux.
5. The apparatus of claim 4, wherein: the external component
includes a skin interface surface; and the apparatus is configured
such that: the tilting of the permanent magnet entails adjusting a
longitudinal axis thereof relative to the skin interface surface;
tilting the permanent magnet such that an angle between the
longitudinal axis and an axis normal to the skin interface surface
is increased decreases the resulting magnetic retention force; and
tilting the permanent magnet such that an angle between the
longitudinal axis and an axis normal to the skin interface surface
is decreased increases the resulting magnetic retention force.
6. The apparatus of claim 1, wherein: the external component
includes a permanent magnet that generates at least a portion of
the generated magnetic flux; and the external component is
configured to enable rotation of the permanent magnet, thereby
adjusting the path of the generated magnetic flux.
7. The apparatus of claim 6, wherein: the external component is
further configured to enable adjustment of the generated magnetic
flux to vary the resulting retention force via at least one of
additive or subtractive interaction of local magnetic flux.
8. The apparatus of claim 1, further comprising: an implantable
component that interacts with the magnetic flux to establish
retention of the external component to the recipient, wherein the
apparatus is configured such that a torque applied to skin of the
recipient is substantially constant through a substantial range of
adjustments of the path of the generated magnetic flux.
9. An apparatus, comprising: an external component of a medical
device including a permanent magnet having a polarity axis, the
external component being configured such that the permanent magnet
at least partially removably retains, via a resulting magnetic
retention force, the external component to a recipient thereof,
wherein the external component is configured to enable the
adjustment of an orientation of the polarity axis.
10. The apparatus of claim 9, wherein: the external component is
configured to enable the adjustment of the generated magnetic flux
without additive and subtractive interaction of local magnetic
flux.
11. The apparatus of claim 10, wherein: the external component is
further configured to enable the adjustment of the generated
magnetic flux via at least one of additive and subtractive
interaction of local magnetic flux.
12. The apparatus of claim 9, wherein: the permanent magnet is a
first permanent magnet having a first polarity axis; and the
apparatus further comprises: a second permanent magnet having a
second polarity axis, wherein the external component is configured
such that the second permanent magnet contributes to the resulting
magnetic retention force so as to at least partially removably
retain, via the resulting magnetic retention force, the external
component to a recipient thereof, and the external component is
configured to enable the adjustment of an orientation of the second
polarity axis.
13. The apparatus of claim 12, wherein: the external component is
configured to enable at least one of rotation and tilting of the
first and second permanent magnets to adjust the orientations of
the respective first and second polarity axes.
14. The apparatus of claim 9, wherein: the permanent magnet is a
first permanent magnet having a first polarity axis; and the
apparatus further comprises: a second permanent magnet having a
second polarity axis, wherein the external component is configured
such that the second permanent magnet contributes to the resulting
magnetic retention force so as to at least partially removably
retain, via the resulting magnetic retention force, the external
component to a recipient thereof, and the external component is
configured to enable the adjustment of an orientation of the second
polarity axis; a third permanent magnet having a third polarity
axis, wherein the external component is configured such that the
third permanent magnet contributes to the resulting magnetic
retention force so as to at least partially removably retain, via
the resulting magnetic retention force, the external component to a
recipient thereof, and the external component is configured to
enable the adjustment of an orientation of the third polarity axis;
and a fourth permanent magnet having a fourth polarity axis,
wherein the external component is configured such that the fourth
permanent magnet contributes to the resulting magnetic retention
force so as to at least partially removably retain, via the
resulting magnetic retention force, the external component to a
recipient thereof, and the external component is configured to
enable the adjustment of an orientation of the fourth polarity
axis.
15. The apparatus of claim 14, wherein: the apparatus is configured
such that a resulting magnetic flux of the external component
establishing the resulting magnetic retention force is
substantially symmetrical about a plane parallel to a longitudinal
axis of the external component throughout a range of orientations
of the polar axes of the first, second third and fourth permanent
magnets.
16. The apparatus of claim 14, further comprising: the apparatus is
configured such that a resulting magnetic flux of the external
component establishing the resulting magnetic retention force is
substantially symmetrical about the longitudinal axis of the
external component throughout a range of orientations of the polar
axes of the first, second, third and fourth permanent magnets.
17. The apparatus of claim 12, wherein: the apparatus includes a
mechanical adjustment apparatus that simultaneously adjusts the
respective orientations of the first and second permanent magnets
so that the first and second poles have equal and opposite
adjustments relative to a longitudinal axis of the external
component.
18. The apparatus of claim 9, wherein: the permanent magnet is a
first permanent magnet having a first polarity axis; and the
apparatus further comprises: a second permanent magnet having a
second polarity axis, wherein the external component is configured
such that the second permanent magnet contributes to the resulting
magnetic retention force so as to at least partially removably
retain, via the resulting magnetic retention force, the external
component to a recipient thereof, and the external component is
configured to enable the adjustment of an orientation of the second
polarity axis; and a third permanent magnet having a third polarity
axis, wherein the external component is configured such that the
third permanent magnet contributes to the resulting magnetic
retention force so as to at least partially removably retain, via
the resulting magnetic retention force, the external component to a
recipient thereof.
19. A method, comprising: obtaining an external component of a
medical device configured to be magnetically retained against outer
skin of a recipient via a magnetic coupling between the external
component and an implanted component in the recipient; and
adjusting a path of a magnetic flux generated by at least one of
the external component or the implanted component such that the
resulting retention force of the magnetic retention for the
recipient is varied from that which was the case prior to the
adjustment.
20. The method of claim 19 further comprising: placing the external
component against a recipient's skin at least one of during or
after adjusting the path such that the external component is
retained against the skin of the recipient via the magnetic
coupling between the external component and the implanted
component, wherein the implanted component includes a magnet
arrangement having a single polarity axis, and the magnetic
coupling results in substantially no torque on the external
component while positioned against the skin of the recipient in the
absence of external forces on the external component.
21. The method of claim 19, further comprising: placing the
external component against a recipient's skin at least one of after
or during adjusting the path such that the external component is
retained against the skin of the recipient via the magnetic
coupling between the external component and the implanted
component, wherein the implanted component includes a magnet
arrangement having a single polarity axis, and the resulting
magnetic flux of the magnetic flux generated by the external
component and the magnet of the implanted component is symmetrical
about a plane parallel to and lying on the single polarity
axis.
22. The method of claim 19, further comprising: placing the
external component against a recipient's skin after adjusting the
path such that the external component is retained against the skin
of the recipient via the magnetic coupling between the external
component and the implanted component, wherein the implanted
component includes a magnet arrangement having a single polarity
axis, and the resulting magnetic flux of the magnetic flux
generated by the external component and the magnet of the implanted
component is symmetrical about a the single polarity axis.
23. The method of claim 19, further comprising: placing the
external component against a recipient's skin at least one of
during or after adjusting the path such that the external component
is retained against the skin of the recipient via the magnetic
coupling between the external component and the implanted
component, wherein the implanted component includes a magnet
arrangement having a multiple polarity axes, and the resulting
magnetic flux of the magnetic flux generated by the external
component and the magnet of the implanted component is symmetrical
about a plane parallel to and lying in between respective axes of
the multiple polarity axes.
24. The method of claim 18, wherein: the action of adjusting the
path of the magnetic flux entails adjusting a trajectory of the
magnetic flux between the external component and the implantable
component.
25. The method of claim 18, wherein: the action of adjusting the
path of the magnetic flux results in lengthening the path between
the external component and the implantable component relative to
that which was the case prior to the adjustment for the same air
gap between respective magnetic components of the external
component and respective magnetic components of the implantable
component, and the resulting retention force is reduced as a result
of the lengthening of the path relative to that which was the case
prior to the adjustment of the path.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Provisional U.S. Patent
Application No. 62/185,288, entitled MAGNETIC RETENTION DEVICE,
filed on Jun. 26, 2015, naming Johan GUSTAFSSON of Molnlycke,
Sweden as an inventor, the entire contents of that application
being incorporated herein by reference in its entirety.
BACKGROUND
[0002] Hearing loss, which may be due to many different causes, is
generally of two types: conductive and sensorineural. Sensorineural
hearing loss is due to the absence or destruction of the hair cells
in the cochlea that transduce sound signals into nerve impulses.
Various hearing prostheses are commercially available to provide
individuals suffering from sensorineural hearing loss with the
ability to perceive sound. For example, cochlear implants use an
electrode array implanted in the cochlea of a recipient to bypass
the mechanisms of the ear. More specifically, an electrical
stimulus is provided via the electrode array to the auditory nerve,
thereby causing a hearing percept.
[0003] Conductive hearing loss occurs when the normal mechanical
pathways that provide sound to hair cells in the cochlea are
impeded, for example, by damage to the ossicular chain or the ear
canal. Individuals suffering from conductive hearing loss may
retain some form of residual hearing because the hair cells in the
cochlea may remain undamaged.
[0004] Individuals suffering from conductive hearing loss typically
receive an acoustic hearing aid. Hearing aids rely on principles of
air conduction to transmit acoustic signals to the cochlea. In
particular, a hearing aid typically uses an arrangement positioned
in the recipient's ear canal or on the outer ear to amplify a sound
received by the outer ear of the recipient. This amplified sound
reaches the cochlea causing motion of the perilymph and stimulation
of the auditory nerve.
[0005] In contrast to hearing aids, which rely primarily on the
principles of air conduction, certain types of hearing prostheses
commonly referred to as bone conduction devices, convert a received
sound into vibrations. The vibrations are transferred through the
skull to the cochlea causing generation of nerve impulses, which
result in the perception of the received sound. Bone conduction
devices are suitable to treat a variety of types of hearing loss
and may be suitable for individuals who cannot derive sufficient
benefit from acoustic hearing aids, cochlear implants, etc, or for
individuals who suffer from stuttering problems.
SUMMARY
[0006] In accordance with an exemplary embodiment, there is an
apparatus comprising an external component of a medical device, and
an implantable component of the medical device, wherein the
apparatus is configured to generate a magnetic flux that removably
retains, via a resulting magnetic retention force, the external
component to a recipient thereof, wherein the external apparatus is
configured to enable the adjustment of a path of the generated
magnetic flux so as to vary the resulting magnetic retention
force.
[0007] In accordance with another exemplary embodiment, there is an
apparatus, comprising an external component of a medical device
including a permanent magnet having a polarity axis, the external
component being configured such that the permanent magnet at least
partially removably retains, via a resulting magnetic retention
force, the external component to a recipient thereof, wherein the
external component is configured to enable the adjustment of an
orientation of the polarity axis.
[0008] In accordance with another exemplary embodiment, there is a
method, comprising obtaining an external component of a medical
device configured to be magnetically retained against outer skin of
a recipient, via a magnetic coupling between the external component
and an implanted component in the recipient, and adjusting a path
of a magnetic flux generated by the external component such that
the resulting retention force of the magnetic retention for the
recipient is varied from that which was the case prior to the
adjustment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Some embodiments are described below with reference to the
attached drawings, in which:
[0010] FIG. 1 is a perspective view of an exemplary bone conduction
device in which at least some embodiments can be implemented;
[0011] FIG. 2 is a schematic diagram conceptually illustrating a
passive transcutaneous bone conduction device in accordance with at
least some exemplary embodiments;
[0012] FIG. 3 is a schematic diagram illustrating additional
details of the embodiment of FIG. 2;
[0013] FIGS. 4A-4C are schematic diagrams illustrating adjustment
of a component of the embodiment of FIG. 3;
[0014] FIGS. 5A-5B are schematic diagrams illustrating exemplary
magnetic flux paths of the embodiment of FIG. 3;
[0015] FIG. 6 depicts another exemplary embodiment;
[0016] FIGS. 7A-7C are schematic diagrams illustrating adjustment
of a component of the embodiment of FIG. 6;
[0017] FIG. 8 depicts another exemplary embodiment;
[0018] FIGS. 9A-9D are schematic diagrams illustrating adjustment
of a component of the embodiment of FIG. 8;
[0019] FIG. 10 is a schematic diagram illustrating exemplary
magnetic flux path of the embodiment of FIG. 8;
[0020] FIGS. 11A-11C are schematic diagrams illustrating adjustment
of components of an exemplary embodiment of FIG. 8;
[0021] FIG. 12 depicts another exemplary embodiment;
[0022] FIGS. 13A-13B depict exemplary magnet configurations of the
exemplary embodiment of FIG. 12;
[0023] FIGS. 14A-14B depict exemplary conceptual magnetic flux
paths according to an exemplary embodiment;
[0024] FIGS. 15A-15D depict another exemplary embodiment; and
[0025] FIG. 16 depicts an exemplary flowchart for an exemplary
method.
DETAILED DESCRIPTION
[0026] FIG. 1 is a perspective view of a bone conduction device 100
in which embodiments may be implemented. As shown, the recipient
has an outer ear 101, a middle ear 102 and an inner ear 103.
Elements of outer ear 101, middle ear 102 and inner ear 103 are
described below, followed by a description of bone conduction
device 100.
[0027] In a fully functional human hearing anatomy, outer ear 101
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 210 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. The ossicles 111 of
middle ear 102 serve to filter and amplify acoustic wave 107,
causing oval window to vibrate. Such vibration sets up waves of
fluid motion within cochlea 139. Such fluid motion, in turn,
activates hair cells (not shown) that line the inside of cochlea
139. 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.
[0028] 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 is positioned behind outer ear 101 of the recipient and
comprises a sound input element 126 to receive sound signals. Sound
input element may comprise, for example, a microphone, telecoil,
etc. In an exemplary embodiment, sound input element 126 may be
located, for example, on or in bone conduction device 100, or on a
cable extending from bone conduction device 100.
[0029] The bone conduction device 100 of FIG. 1 is a passive
transcutaneous bone conduction device utilizing the electromagnetic
actuators disclosed herein and variations thereof where no active
component (e.g., the electromagnetic actuator) is implanted beneath
the skin (it is instead located in an external device), and the
implantable part is, for instance a magnetic pressure plate (a
permanent magnet, ferromagnetic material, etc.). Some embodiments
of the passive transcutaneous bone conduction systems are
configured for use where the vibrator (located in an external
device) containing the electromagnetic actuator is held in place by
pressing the vibrator against the skin of the recipient. In an
exemplary embodiment, the vibrator is held against the skin via a
magnetic coupling (magnetic material and/or magnets being implanted
in the recipient and the vibrator having a magnet and/or magnetic
material that used to complete the magnetic circuit, thereby
coupling the vibrator to the recipient).
[0030] More specifically, FIG. 1 is a perspective view of a passive
transcutaneous bone conduction device 100 in which embodiments can
be implemented.
[0031] Bone conduction device 100 comprises an external component
140 and an implantable component 150. Bone conduction device 100
comprises a sound processor (not shown), an actuator (also not
shown) and/or various other operational components. In operation,
sound input device 126 converts received sounds into electrical
signals. These electrical signals are utilized by the sound
processor to generate control signals that cause the actuator to
vibrate. In other words, the actuator converts the electrical
signals into mechanical vibrations for delivery to the recipient's
skull.
[0032] In accordance with some embodiments, a fixation system 162
may be used to secure implantable component 150 to skull 136. As
described below, fixation system 162 may be a bone screw fixed to
skull 136, and also attached to implantable component 150.
[0033] In one arrangement of FIG. 1, bone conduction device 100 is
a passive transcutaneous bone conduction device. In such an
arrangement, the active actuator is located in external component
140, and implantable component 150 includes a plate, as will be
discussed in greater detail below. The plate of the implantable
component 150 vibrates in response to vibration transmitted through
the skin, mechanically and/or via a magnetic field, that are
generated by an external magnetic plate.
[0034] FIG. 2 depicts a functional schematic of an exemplary
embodiment of a transcutaneous bone conduction device 300 according
to an embodiment that includes an external device 340
(corresponding to, for example, element 140 of FIG. 1) and an
implantable component 350 (corresponding to, for example, element
150 of FIG. 1). The transcutaneous bone conduction device 300 of
FIG. 3 is a passive transcutaneous bone conduction device in that a
vibrating electromagnetic actuator 342 is located in the external
device 340. Vibrating electromagnetic actuator 342 is located in
housing 344 of the external component, and is coupled to plate 346.
In an exemplary embodiment, the vibrating electromagnetic actuator
342 is a device that converts electrical signals into vibration. In
operation, sound input element 126 converts sound into electrical
signals. Specifically, the transcutaneous bone conduction device
300 provides these electrical signals to vibrating actuator 342, or
to a sound processor (not shown) that processes the electrical
signals, and then provides those processed signals to vibrating
electromagnetic actuator 342. The vibrating electromagnetic
actuator 342 converts the electrical signals (processed or
unprocessed) into vibrations. Because vibrating electromagnetic
actuator 342 is mechanically coupled to plate 346, the vibrations
are transferred from the vibrating actuator 342 to plate 346.
Implanted plate assembly 352 is part of the implantable component
350, and is made of a ferromagnetic material that may be in the
form of a permanent magnet, that generates and/or is reactive to a
magnetic field, or otherwise permits the establishment of a
magnetic attraction between the external device 340 and the
implantable component 350 sufficient to hold the external device
340 against the skin of the recipient, as will be detailed further
below. Accordingly, vibrations produced by the vibrating
electromagnetic actuator 342 of the external device 340 are
transferred from plate 346 across the skin to plate 355 of
implanted plate assembly 352. This can be accomplished as a result
of mechanical conduction of the vibrations through the skin,
resulting from the external device 340 being in direct contact with
the skin and/or from the magnetic field between the two plates.
These vibrations are transferred without penetrating the skin with
a solid object such as an abutment as detailed herein with respect
to a percutaneous bone conduction device.
[0035] As may be seen, the implanted plate assembly 352 is
substantially rigidly attached to a bone fixture 341 in this
embodiment. Plate screw 356 is used to secure plate assembly 352 to
bone fixture 341. The portions of plate screw 356 that interface
with the bone fixture 341 substantially correspond to an abutment
screw discussed in some additional detail below, thus permitting
plate screw 356 to readily fit into an existing bone fixture used
in a percutaneous bone conduction device. In an exemplary
embodiment, plate screw 356 is configured so that the same tools
and procedures that are used to install and/or remove an abutment
screw (described below) from bone fixture 341 can be used to
install and/or remove plate screw 356 from the bone fixture 341
(and thus the plate assembly 352).
[0036] Referring now to FIG. 3, there is depicted a schematic of an
exemplary bone conduction device 300A corresponding to bone
conduction device 300 of FIG. 2. The exemplary bone conduction
device 300A of FIG. 3 includes an external component 340A
corresponding to external component 340 of FIG. 2, and an
implantable component 350A corresponding to implantable component
350 of FIG. 2.
[0037] In an exemplary embodiment, external component 340A has the
functionality of a transducer/actuator, irrespective of whether it
is used with implantable component 350A. That is, in some exemplary
embodiments, external component 340A will vibrate whether or not
the implantable component 350A is present (e.g., whether or not the
static magnetic field extends to the implantable component 350A, as
will be detailed below).
[0038] The external component 340A includes a vibrating actuator
represented in black-box format by reference numeral 342A. In an
exemplary embodiment, the vibrating actuator can be an
electromagnetic actuator. Alternatively, in some alternate
embodiments, the vibrating actuator 342A can be a piezoelectric
actuator. Any type of an actuator that can enable the teachings
detailed herein and/or variations thereof to be practiced can be
utilized in at least some exemplary embodiments. That said,
embodiments detailed herein will be described, by way of example
only and not by way of limitation, in terms of a vibrating
electromagnetic actuator that utilizes a bobbin about which is
wound a coil that is energized and deenergized in an alternating
manner, so as to produce an electromagnetic field that interacts
with permanent magnets that move a seismic mass in a vibratory
matter in a direction of arrow 399.
[0039] Still with reference to FIG. 3, the vibrating
electromagnetic actuator 342A is enclosed in a housing 344A, as can
be seen. In some embodiments, the housing 344A is a hermetically
sealed housing, while in other embodiments, it is not hermetically
sealed. In at least some exemplary embodiments, the housing 344A is
configured to provide the actuator 342A protection from shock and
environmental conditions, etc. Any housing that can enable the
teachings detailed herein and/or variations thereof can be utilized
in at least some embodiments. In this regard, as can be seen, the
housing 344A is rigidly attached to skin interface portion 346A,
which functionally corresponds to plate 346 of FIG. 2 detailed
above, by structural component 348. In this exemplary embodiment,
the structural component 348 provides a vibrational conduction path
such that vibrations generated by actuator 342A are transferred
from the housing to the skin interface component 346A, such that
those vibrations can then be transferred into the skin of the
recipient to ultimately evoke a hearing percept according to the
teachings detailed herein and/or variations thereof.
[0040] In at least some embodiments, skin interface portion 346A
serves a dual role in that it both transfers vibrations from the
external component 340A to the skin and also magnetically couples
the external component 340A to the recipient. In this regard, as
can be seen, skin interface portion 346A includes a housing 347
that includes an external magnet assembly 358EX. External magnetic
assembly 358EX includes a permanent magnet (as shown in FIG. 3, but
in alternate embodiments, the external magnet assembly 358EX can
have a plurality of magnets) having a North-South alignment (or a
plurality of magnets collectively resulting in the external magnet
assembly 358EX having a North-South alignment. As will be detailed
in greater detail below, the external magnet assembly 358EX is
tiltable relative to the longitudinal axis 390 of the external
component/the housing 347/surface 391. As can be seen, the magnet
assembly 358EX has a North Pole away from actuator 342A (i.e.,
toward the skin of the recipient). That is, the North-South
alignment of the external magnet assembly 358EX is oriented towards
skin of the recipient. However, in other exemplary embodiments of
the external component 340A, the poles are different than that
depicted in FIG. 3. In an exemplary embodiment, the permanent
magnet of magnet assembly 358EX is a disk magnet.
[0041] It is noted that the word "adjustable" and "tiltable" as
used herein excludes replacement of one magnet with another magnet,
that being a reconfiguration or a modification to the device.
[0042] Skin interface portion 346A includes a bottom surface 391
(relative to the frame of reference of FIG. 3) that is configured
to interface with the exterior skin of the recipient. In this
regard, skin interface portion 346A corresponds to plate 346 of
FIG. 2 as described above. It is through skin interface portion
346A that vibrations generated by the electromagnetic actuator of
the external component 340A are transferred from the external
component 340A to the skin of the recipient to evoke a hearing
percept. In an exemplary embodiment, the housing 347 of the skin
interface portion 346A is made of a non-ferromagnetic material that
is compatible with skin of the recipient (or at least is coated
with a material that is compatible with skin of the recipient). In
this regard, in at least some exemplary embodiments, the housing
347 is configured to substantially avoid influencing the magnetic
flux generated by the permanent magnet of the external magnet
assembly 358EX.
[0043] FIG. 3 also depicts an implantable component 350A
corresponding to implantable component 350 of FIG. 2. In some
embodiments, implantable component 350 includes an implantable
magnet assembly 358IM that includes single permanent magnet, such
as a doughnut magnet (depicted in FIG. 3 in cross-sectional view
without background structure for clarity). The permanent magnet has
a North-South alignment in a first direction relative to a
longitudinal axis of the electromagnetic actuator (the vertical
direction of FIG. 3). In the exemplary embodiment of FIG. 3, the
permanent magnet assembly has a North-South alignment with the
South Pole facing the external component 340A (the surface of the
skin of the recipient). That said, in an alternate embodiment, as
with the external magnet assembly 358EX, the implantable magnet
assembly 358IM can include a plurality of magnets that are arrayed
such that the overall assembly has a polar axis as desired.
[0044] In an exemplary embodiment, the chassis 359 that supports or
otherwise retains the permanent magnet(s) of the implantable magnet
assembly 358IM is a nonmagnetic material (e.g., titanium). It is
noted that in alternative embodiments, other configurations can be
utilized. Any configuration of a permanent magnet assembly that can
enable the teachings detailed herein and/or variations thereof to
be practiced can be utilized in at least some embodiments.
[0045] That said, in an alternative embodiment, it is noted that
the implantable component 350A does not include permanent
magnet(s). In at least some embodiments, the permanent magnet is
replaced with other types of ferromagnetic material (e.g., soft
iron (albeit encapsulated in titanium, etc.)). In the embodiment of
FIG. 3, the magnet of assembly 358IM is a single, monolithic
component, but in alternate embodiments, the assembly 358IM uses
multiple magnets. Any configuration of ferromagnetic material of
the implantable component 350A that will enable the permanent
magnets of the external component 340A to establish a magnetic
coupling with the implantable component 350A that will enable the
external component 340A to be adhered to the surface of the skin,
as detailed herein, can be utilized in at least some
embodiments.
[0046] As can be seen, implantable component 350A includes screw
component 356A configured to screw into bone fixture 341 and thus
secure the chassis 359 to the bone fixture 341, and thus to the
recipient.
[0047] Referring back to the external component 340A, there is seen
an apparatus (bone conduction device 300A), comprising an external
component 340A including a permanent magnet 358EX having a polarity
axis (the N-S axis, as seen). In an exemplary embodiment, the
external component 340A is configured such that the permanent
magnet 358EX at least partially removably retains, via a resulting
magnetic retention force, the external component 340A to a
recipient thereof, wherein the external component 340a is
configured to enable the adjustment of an orientation of the
polarity axis of the permanent magnet assembly 358EX. In an
exemplary embodiment, this adjustment of the orientation of the
polarity axis is achieved by tilting the permanent magnet assembly
358EX.
[0048] In an exemplary embodiment, as will be discussed in greater
detailed below, the adjustments of the orientation of the polarity
axis of the permanent magnet assembly 358EX enables adjustment of a
path of the generated magnetic flux that is generated by the
permanent magnets of the permanent magnet assembly 358EX. In an
exemplary embodiment, this varies the resulting magnetic retention
force between the external component 340A and the implantable
component 350A, also as detailed below.
[0049] In this regard, in at least some exemplary embodiments,
during operational use of the bone conduction device 300A, the
external magnet assembly 358EX has a polar axis aligned with the
magnets of the implantable magnet assembly 358IM such that the
poles of the external magnet assembly 358EX have a North-South
alignment in exactly the same direction as the implantable magnet
assembly 358IM, in a scenario where maximum attractive force
between the external component 340A and the implantable component
350A is desired. This is depicted in FIG. 3.
[0050] Conversely, in at least some exemplary embodiments, during
operational use of the bone conduction device 300A, the external
magnet assembly 358EX is tilted such that the North-South axis is
misaligned with the North-South axis of the implantable magnet
assembly 358IM, not because the external component 340A has been
globally tilted relative to the implantable component 350A (or,
alternatively, the effective reduction in force is not due to the
external component 340A being globally tilted to the implantable
component 350A--the external component may tilt a bit, but the
effect of the tilt is relatively negligible on the variation of the
retention force), but because of the adjustability of the external
magnet assembly 358EX due to the tiltability feature.
[0051] The above adjustability can be conceptually seen in FIGS.
4A-C, which conceptually depict respective isometric views of the
external magnet assembly and the internal magnet assembly without
any of the components of the bone conduction device 300A. More
specifically, FIG. 4A depicts a configuration of the external
magnet assembly 358EX such that the maximum attraction force
between the external component 340A and 350A is achieved. Briefly,
with respect to the frame of reference of FIGS. 4A-4C, the view of
these figures corresponds to the plane of FIG. 3 except that the
viewer is looking slightly from the top.
[0052] As can be seen in FIG. 4A, the magnet of the external
component is a single disc shaped magnet, and the magnet of the
implantable component is a single doughnut shaped magnet. As will
be detailed below, other configurations can be utilized.
[0053] FIG. 4B depicts the external magnet assembly 358EX tilted by
a first amount relative to the location of that assembly depicted
in FIG. 4A (and thus having an angular offset relative to the
longitudinal axis 390). In these embodiments, whereas the
configuration of FIG. 4A results in the strongest attraction force
(for a given air gap between the external magnet assembly 358EX and
the implantable magnet assembly 358IM--more on this below) between
the external component 340A and the implantable component 350A, the
configuration of FIG. 4B results in an attraction force that is in
between that FIG. 4A and FIG. 4C detailed below (again for the
given air gap) between the external component 340A and the
implantable component 350. FIG. 4C depicts the external magnet
assembly 358EX tilted by a second amount relative to the location
of that assembly depicted in FIG. 4A, where the second amount is
about twice that amount of the difference between FIGS. 4A and 4B.
In these embodiments, whereas the configuration of FIG. 4A results
in the strongest attraction force (for a given air gap between the
external magnet assembly 358EX and the implantable magnet assembly
358IM--more on this below) between the external component 340A and
the implantable component 350A, the configuration of FIG. 4C
results in an attraction force that is the weakest (relative to
FIGS. 4A and 4B), again for the given air gap, between the external
component 340A and the implantable component 350.
[0054] It is noted that the amount of tilting depicted in FIGS.
4A-4C is simply exemplary and presented for conceptual purposes.
The actual amount of tilting can vary depending on the utilitarian
features to be achieved. Moreover, while three different tilt
amounts are depicted in the figures, respectively, some embodiments
will utilize fewer or more tilt amounts. In an exemplary
embodiment, the tilt amount is defined by discrete increments
(e.g., a digital arrangement). By way of example only and not by
way of limitation, the external component can be configured such
that the external magnet assembly 358EX can set at a tilt angle of
0 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees, 30
degrees, 40 degrees or 45 degrees. Fewer or more increments can be
provided. Each setting will result in a discrete attraction force
for a given airgap. Alternatively and/or in addition to this, the
external component can be configured such that the external magnet
assembly 358EX can be set at a tilt angle in an analogue manner.
That is, the tilt angle can be set at basically any angle limited
only by the fine adjustment abilities of the mechanical adjustment
system (or electromechanical adjustment system, if such is used).
Accordingly, in an exemplary embodiment, the tilt angle can be set
at an unlimited number of different tilt angles (when the last
decimal place is taken into account), limited only by the fine
adjustment capabilities of the system and/or the user.
[0055] Any device, system or method that will enable the teachings
detailed herein and/or variations thereof to be practiced can be
utilized in at least some embodiments.
[0056] The physical phenomenon that results in the differences
between the attraction force of the different configurations will
now be described, followed by some exemplary embodiments of the
structure of the bone conduction device implementing some such
embodiments.
[0057] FIG. 5A depicts a quasi-functional diagram of a
cross-section of the external and implantable magnet assemblies
corresponding to the plane of FIG. 3 with the magnets in the
arrangement as presented in FIG. 4A, with the magnetic flux
following a magnetic flux path 500A. It is noted that the magnetic
flux paths presented herein are presented as conceptual diagrams
only to illustrate general physical phenomenon that Applicant
utilizes in some embodiments. These are simplified versions of the
generally more complex flux paths that occur, and are presented for
purposes of illustration only. In at least some embodiments,
applicants utilize the exact flux paths that would result utilize a
permanent magnets as detailed herein and/or variations thereof.
[0058] FIG. 5A depicts an air gap, and is linked to the distance
AG1, representing the space between the external magnet assembly
358EX and the implantable magnet assembly 358IM as measured from
the center of both magnet assemblies. In this regard, it is noted
that the traditional concept of air gap, which is the distance from
the surfaces of the magnets facing one another, has been adjusted
somewhat from its conventional use by measuring the air gap from
the centerlines of the magnets. In this regard, because when the
air gap is measured from the outer surfaces of the magnets, the air
gap will change due to the tilting of the magnet assembly if
measured at a location away from the centroid, a more stable
reference is useful in terms of speaking of the air gap. That said,
in an alternate embodiment, the air gap can be measured from the
centroid at the outer surface of the magnet, if the magnet is
configured such that the rotation axis is on the bottom surface.
(The aforementioned exemplary scenario is based on the magnet
assembly 358EX being rotated through the center of the magnet--the
center does not move relative to the longitudinal axis.)
[0059] It is noted that the phrase "air gap" refers to locations
along the magnetic flux path in which little to no material having
substantial magnetic aspects is located but the magnetic flux still
flows through the gap. The air gap closes the magnetic field.
Accordingly, an air gap is not limited to a gap that is filled by
air. Indeed, in at least some embodiments, there is always some
form of solid and/or liquid matter located between the opposing
faces of the external and internal magnet assemblies (skin, fat,
body fluids, the material of the chassis 359, material of the
housing 347, etc.).
[0060] As can be seen, in an exemplary embodiment, the magnetic
flux path 500A travels in a circuit through the external magnet
assembly and the implantable magnet assembly. Arrows 511 depict the
relative localized strength of the magnetic flux and the direction
thereof in between the magnets of the external magnet assembly
358EX and the implantable magnet assembly 358IM (the strength and
direction of the magnetic flux at those local locations within the
air gap AG1). With respect to the cross-sectional view of FIG. 5A,
the magnetic flux travels in a circulatory fashion--downward at the
center of the air gap, as is represented by arrows 511, consistent
with the fact that all of the poles of the magnets are aligned, and
then outwards at the bottom, and then upwards at the outside of the
flux, and then inwards at the top, and then down. Alternatively, if
all of the magnetic poles were reversed from that seen in the
figures, the magnetic flux would be in the opposite direction. Any
direction of magnetic flux that will enable the teachings detailed
herein and/or variations thereof to be practiced can be utilized in
at least some embodiments.
[0061] Conversely, FIG. 5B depicts a quasi-functional diagram of a
cross-section of the external and implantable magnet assemblies
also taken through plane of FIG. 3, with the magnets in the
arrangement as presented in FIG. 4B, with the magnetic flux path
500B superimposed thereon. FIG. 5B depicts an air gap AG1, where
the air gap AG1 is exactly the same distance as that of FIG. 5A in
this exemplary embodiment (FIG. 5B depicting the utility of
measuring the air gap AG1 from the midpoints of the magnets).
[0062] As can be seen, in an exemplary embodiment, the magnetic
flux has a magnetic flux path 500B that is shifted/angled relative
to which was the case in FIG. 5A. The flux path 500B is changed
from 500A due to the tilting of the magnet assembly 358EX. However,
owing to the fact that the implantable magnet assembly 358IM is not
tilted, the shift of the magnetic flux path is not as extreme as
that which would be the case in the absence of the implantable
magnet assembly 358IM (or at least that which would be the case in
the absence of the implantable magnet assembly 358IM having
permanent magnets that also generate a magnetic flux, that is
combined with that generated by the external component to generate
the resulting magnetic flux 500B). (Thus, as will be understood,
the external component generates a portion of the total generated
magnetic flux of the bone conduction device 300A in embodiments
where the implantable magnet assembly 358IM includes a permanent
magnet.) This phenomenon can be seen by comparing the angle of
arrow 511 to the longitudinal axis 390 of the external component
340A to the longitudinal axis 597 of the external magnet assembly
358EX (where the angle between those two axes represents the amount
of tilt of the external magnet assembly 358EX relative to zero
tilting). In the absence of influence of the internal magnet
assembly 358IM, the arrow 511 would lie on or at least closer to
axis 597, and the magnetic flux 500B would be symmetrical, or at
least more symmetrical, about axis 597.
[0063] Generally speaking, the tilting of the magnetic flux path
relative to that which exists at the zero tilt angle results in
reduced attraction force between the external component of the
implantable component, all other things being equal. In an
exemplary embodiment, the more that the tilt angle increases from
zero, the greater the reduction in retention force (in the micro
geometry--once the magnet flips, the external component will be
repelled by the implantable component--in at least some
embodiments, the external component will not configured so as to
enable the external magnet assembly 358EX to be flipped over).
Thus, the aforementioned physical phenomenon is described in terms
of the contemplated embodiments having utilitarian value with
respect to retention).
[0064] Thus, an exemplary embodiment entails adjusting the
orientation of the external magnet assembly 358EX and thus
adjusting the orientation of the polar axis thereof to adjust a
path of the generated magnetic flux generated by the external
magnet assembly 358EX to vary the resulting magnetic retention
force relative to that which would be the case in the absence of
the tilting.
[0065] The resulting reduction in retention force is functionally
represented by the fact that arrows 511 have been shortened in FIG.
5B relative to that which is the case in FIG. 5A. Accordingly, the
resulting retention force holding the external component 350A
against the skin of the recipient is lower than the resulting
retention force of the magnetic flux of FIG. 5A.
[0066] Accordingly, in at least some exemplary embodiments, the
bone conduction device 300A is configured such that the strength of
the magnetic flux generated, at least in part (the implantable
component can generate a portion of the magnetic flux, at least
when the implantable component utilizes permanent magnets as well),
by the external component can be varied for a given air gap AG1 and
a given orientation of the external component 340A relative to the
implantable component 350A, by adjusting the path of the generated
magnetic flux. That is, by way of example only and not by way of
limitation, holding all other variables constant, the magnetic flux
path that retains the external component 340A to the implantable
component 350A can be varied such that the resulting retention
force that holds the external component 340A to the skin of the
recipient is also varied by adjusting the orientation of at least
one permanent magnet of the external component 340A, relative to
the global geometry of the external component 340A, and thereby
adjusting the resulting path. (The global geometry of the external
component is represented by axis 390. By analogy, the global
geometry of a car does not change even though one may adjust the
locations of the seats or the steering wheel.) Unless otherwise
specified, axis 390 is normal to the local direction of the skin
surface at the location through which axis 390 penetrates the skin
(normal to the tangent line of the skin surface at that
location).
[0067] It is noted that this is different than creating additional
paths for the magnetic flux to flow through, such as may result if
the magnetic flux paths are short-circuited. It is also noted that
this is also different than decreasing the magnetic flux density.
While the former does result in new flux paths, the overall flux
path remains (albeit in a weakened state). By analogy, adding
additional on-ramps and off-ramps to a highway or adding additional
lanes or adding a "beltway" or "express route" (that bypasses, for
example, the center of a city entirely, whereas the highway sill
passes through the center of the city) does not change the path of
the highway). With regard to the latter, again, by way of analogy,
simply decreasing the amount of traffic on a given highway by
adding the bypasses or simply by limiting the number of cars
permitted to utilize the highway does not change the path of the
highway.
[0068] In an exemplary embodiment, the concept of changing the path
of the generated magnetic flux can be defined in terms of changing
the path through which the greatest amount of magnetic flux
travels. In this regard, with reference to FIGS. 5A and 5B, it can
be seen that the greatest amount of magnetic flux travels through
the center of the magnet assemblies, and that this path has been
changed.
[0069] Indeed, in an exemplary embodiment, the change in the flux
path variously shortens or lengthens the overall path that the flux
travels from the external component to the internal component (as
opposed to changing the length of the path by adding another path
that does not extend from the external component to the internal
component, as can be the case in additive or subtractive flux
embodiments). In this regard, again with the analogy to automobile
transportation, the length of a path from Los Angeles to New York
City would be lengthened if the path extended through New Orleans
instead of St. Louis, but it is not a lengthened path simply
because one could drive from Los Angeles to St. Louis, then to New
Orleans and back to St. Louis, then to New York.
[0070] In an exemplary embodiment, a relatively longer path of the
flux from the external component to the internal component reduces
the attraction force between the two components relative to that
which would be the case for the shorter path, and visa-versa.
Again, note that all of these are for an effectively static air gap
(the effective distance between the external magnet assembly and
the internal magnet assembly does not substantially change
(including not change)). While there may be some local movement of
the external magnet assembly owing to the tilting or rotation, that
movement amount has a negligible effect on the reduction in force.
Also, such movement would only reduce the linear distance between
the external component and the implantable component, whereas the
variation of the path changes the overall trajectory of the path
such that the length of the path is changed. Accordingly, in an
exemplary embodiment, there is an exemplary method of varying the
magnetic attractive force between the external component and the
implantable component by lengthening the path of the magnetic flux
between the external component and the implantable component while
maintaining the air gap between the external component and the
implantable component effectively constant (by effectively
constant, it is meant that any change in force resulting from any
change in air gap distance that might result is minor (less than
25%, less than 10%, etc.) relative to that which results from the
tilting and/or rotation of the magnets).
[0071] In view of the above, in an exemplary embodiment, the
aforementioned change in the length of the magnetic flux path is
achieved by varying the trajectory of the magnetic flux path
between the external component and the internal component.
[0072] Thus, in view of the above, an exemplary embodiment includes
an external component that includes a permanent magnet that
generates at least a portion of a generated magnetic flux that is
used to retain the external component to the recipient. The
external component is configured to enable tilting of the permanent
magnet (and/or, in some alternate embodiments, rotation of the
magnet, discussed in greater detail below), thereby adjusting the
path of the generated magnetic flux). Concomitant with the
utilitarian nature of a passive transcutaneous bone conduction
device, the external component includes a skin interface surface as
noted above. The action of tilting or otherwise adjusting the
permanent magnet entails adjusting a longitudinal axis thereof
relative to the skin interface surface. The external component is
configured such that tilting of the permanent magnets so that the
angle between the longitudinal axis and an axis normal to the skin
interface surface is increased, decreases the resulting magnetic
retention force between the external component in the implantable
component. The external component is also configured such that
tilting the permanent magnet so that an angle between the
longitudinal axis and an axis normal to the skin interface surface
is decreased, increases the resulting magnetic retention force
between the external component in the implantable component.
[0073] As noted above, in at least some embodiments, rotation of
the permanent magnet of the external component can be utilized to
vary or otherwise adjust the path of the generated magnetic flux.
In this regard, in an exemplary embodiment, the external component
is configured to enable rotation of the permanent magnet.
[0074] Thus, in view of the above, in an exemplary embodiment,
there is an apparatus, comprising an external component of a
medical device, such as, by way of example only and not by way of
limitation, external component 340 of FIG. 3, and an implantable
component of a medical device, such as the implantable component
350 of FIG. 3, configured to generate a magnetic flux (e.g., via
permanent magnets, which generation is thus passive) that removably
retains, via a resulting magnetic retention force, the external
component (e.g., 340A) to the recipient thereof. In this exemplary
embodiment, the external component is configured to enable the
adjustment of the path of the generated magnetic flux so as to vary
the resulting magnetic retention force (as will be detailed below,
in an alternate embodiment, the implantable component or both the
external component and the implantable component are configured to
vary the generated magnetic flux path). In this regard, as seen
from the above, at least some exemplary embodiments accomplish this
by tilting the permanent magnets (although in an alternative
embodiment, as will be detailed below, some exemplary embodiments
accomplish this by rotating the permanent magnet, such that the
magnetic polar axis orientation is changed). Corollary to this is
that in at least some exemplary embodiments, the external component
is configured to enable the adjustment of the path of the generated
magnetic flux without varying a total magnetic density of permanent
magnets of the external component generating the magnetic flux.
[0075] Still further, in an exemplary embodiment of this exemplary
embodiment, the external component is configured to enable the
adjustment of the path of the generated magnetic flux without at
least one of additive or subtractive interaction of local magnetic
flux (e.g., by creating and/or varying the short-circuit in the
magnetic flux, by, for example, altering/adjusting the relative
locations of one or more of the permanent magnets that generate the
magnetic flux).
[0076] That said, in an alternate embodiment, the external
component is further configured to enable adjustment of the
generated magnetic flux to vary the resulting retention force via
at least one of additive or subtractive interaction of local
magnetic flux.
[0077] An alternate embodiment where the external component
utilizes a plurality of permanent magnets will now be
described.
[0078] Referring now to FIG. 6, there is depicted a schematic of an
exemplary bone conduction device 600A corresponding to bone
conduction device 300 of FIG. 2. The exemplary bone conduction
device 600A of FIG. 6 includes an external component 640A
corresponding to external component 340 of FIG. 2, and an
implantable component 350A corresponding to implantable component
350 of FIG. 2 (and that of FIG. 3).
[0079] In an exemplary embodiment, external component 640A has the
functionality as detailed above with respect to external component
340A, and is identical thereto, save for the fact that it utilizes
a plurality of magnets in the external permanent magnet assembly,
as will now be described. In this regard, as can be seen, skin
interface portion 346A includes a housing 347 that includes an
external magnet assembly 658EX. External magnetic assembly 658EX
includes permanent magnets having a North-South alignment. These
magnets are tiltable relative to one another and relative to the
global geometry of the external component, as will be detailed
below. In the configuration depicted in FIG. 6 (without tilting, as
will be detailed below), the magnets of the magnetic assembly
658EX, relative to the longitudinal axis 390 of the bone conduction
device 300A, all have North Poles facing away from the actuator
342A (i.e., towards the skin of the recipient). However, exemplary
embodiments of the external component 640A are configured such that
the polarities opposite that is the figure.
[0080] The implantable component 350A is identical to that detailed
above with respect to FIG. 3. In this regard, a single permanent
magnet of the doughnut shape is utilized. That said, in an
alternative embodiment, a plurality of magnets are utilized as
well, as will be detailed below with respect to an alternate
embodiment.
[0081] Again, it is noted that in an alternative embodiment, it is
noted that the implantable component 350A does not include
permanent magnets. In at least some embodiments, the permanent
magnet thereof can be replaced with other types of ferromagnetic
material (e.g., soft iron (albeit encapsulated in titanium, etc.)).
Also, the implantable magnet assembly 358IM can include separate
magnets (i.e., the magnet assembly 358IM is not a single,
monolithic component). Any configuration of ferromagnetic material
of the implantable component 350A that will enable the permanent
magnets of the external component 340A to establish a magnetic
coupling with the implantable component 350A that will enable the
external component 340A to be adhered to the surface of the skin,
as detailed herein, can be utilized in at least some
embodiments.
[0082] Referring back to the external component 640A, and, more
particularly, to the external magnetic assembly 658EX of the skin
interface portion 346A, it can be seen that the external magnetic
assembly 658EX comprises two different magnets arrayed about the
longitudinal axis 390. There is permanent magnet 658A and permanent
magnet 658B. As will be seen below, the permanent magnets of the
external component 640A are half circle type magnets.
[0083] During operational use of the bone conduction device 600A,
the magnets of the external magnet assembly 658EX are aligned with
the magnets of the implantable magnet assembly 358IM, such that the
poles of the permanent magnets 658A and 658B have a North-South
alignment in exactly the same direction and the poles of the
permanent magnet of permanent magnet assembly 358IM, in a scenario
where maximum attractive force between the external component 640A
and the implantable component 350A is desired. Conversely, in at
least some exemplary embodiments, during operational use of the
bone conduction device 600A, the magnets of the external magnet
assembly 658EX are tilted in a controlled manner such that their
polarity axes are non-aligned with the axes of magnets of the
implantable magnet assembly 658IM, not because the external
component 640A has been tilted relative to the implantable
component 350A (or, alternatively, not entirely because the
external component 640A has been rotated relative to the
implantable component 350A), but because of the adjustability of
the relative position of the magnets 658A and/or 658B.
[0084] The above tiltability can be conceptually seen in FIGS. 7A
and 7B, which conceptually depict respective isometric views of the
external magnet assembly and the internal magnet assembly, without
any of the components of the bone conduction device 300A. More
specifically, FIG. 7A depicts a configuration of the external
magnet assembly 658EX such that the maximum attraction force
between the external component 640A and 350A is achieved.
[0085] As can be seen in FIG. 7A, the magnets of the external
component are segmented into 2 half-circle shaped magnets of
approximately equal area. In embodiments corresponding to FIGS.
7A-7B, the external component 640A is configured such that the
magnets thereof can be moved to have a different angular
configuration relative to that depicted in FIG. 7A. Accordingly,
FIG. 7B depicts the magnets of external magnet assembly 658EX
tilted relative to the location of those magnets depicted in FIG.
7A. It is noted that the arrangement of FIG. 7A depicts two (2)
magnets in the external component (aside from any magnets that may
be present in, for example, the transducer). As will be detailed
below, an alternative embodiment includes more than 2 magnets. Any
number of the magnets that can enable the teachings detailed herein
and/or variations thereof to be practiced can be utilized in at
least some exemplary embodiments.
[0086] It is noted that while the embodiment of FIG. 7B depicts the
permanent magnets of the external assembly 658EX being tilted by
the same amount (albeit in opposite directions relative to the
longitudinal axis 390), in alternative embodiment, the extra
component 640A is configured such that the angle of tilted can be
very between the two permanent magnets, as can be seen in FIG.
7C.
[0087] The end result of the embodiment of FIGS. 6-7C is that the
tilting of the magnets can vary the path of the resulting magnetic
flux/field, so as to vary the retention force between the external
component the implantable component. The conceptual magnetic flux
paths will not be described in detail, as the person of ordinary
skill in the art would understand, at least through
experimentation, the various paths that the magnetic flux is would
take based on the varying angle of the magnets.
[0088] Accordingly, in an exemplary embodiment, the external
component includes a first and second permanent magnet having
respective polarity axes. The external component is configured such
that the first and second permanent magnets contribute to the
resulting magnetic retention force so as to at least partially
removably retain, via the resulting magnetic retention force, the
external component to a recipient thereof. The external component
is configured to enable the adjustment of an orientation of the
second polarity axis, and thereby adjust the path of the magnetic
fluxs that is generated by the first and second magnets of the
external component.
[0089] It is noted that in an exemplary embodiment, the external
component 640A is configured such that there exists a mechanical
adjustment apparatus that simultaneously adjusts the respective
orientations of the first and second permanent magnets so that the
first and second poles have equal and opposite adjustments relative
to a longitudinal axis of the external component. By way of example
only and not limitation, in an exemplary embodiment, this is
achieved by a gear mechanism, or by a cam mechanism, or by a rotary
actuator, or a geared linear actuator, etc. Any device, system,
and/or method that can enable tilting of the magnet in
synchronization can be utilized in at least some embodiments. It is
further noted that any of the aforementioned arrangements can be
utilized with respect to the single permanent magnet arrangement of
FIG. 3, providing that such can have utilitarian value.
[0090] In this regard, by way of example, in some exemplary
embodiments, the external component is a wearable medical device
comprising a housing with a skin interface (e.g., formed by a
platform of rigid material, such as PEEK, or by a soft pad
material, such as a closed-cell foam) and a magnet that forms a
transcutaneous magnetic circuit with an implanted component to
secure the medical device to a recipient. The medical device of
these exemplary embodiments has an adjustable yoke that mounts the
magnet to the housing and a mechanical drive assembly that moves
the yoke to rotate or otherwise move a polarity axis of the magnet
relative to the skin interface of the housing. The mechanical drive
assembly is capable of moving of the yoke from a first position,
where the polarity axis of the magnet is generally normal to the
skin interface, to a second position, where the polarity axis is
offset from the skin interface. This facilitates adjustment of the
magnetic retention force securing the wearable medical device to a
recipient via modification of the transcutaneous magnetic circuit
formed with the implantable component. In some embodiments, the
yoke of these embodiments is adjustable to change the trajectory of
a magnetic flux path that defines the transcutaneous magnetic
circuit. The magnetic flux path is shortest in the first position
when the polarity axis of the magnet is generally normal to the
skin interface. Movement of the yoke from the first position to the
second position lengthens the flux path (or visa-versa). This
reduces the magnetic retention force securing the wearable medical
device to the recipient. The medical device can also comprise a
plurality of magnets that that are adjustable via a compound yoke
assembly or separate yokes with individual drive assemblies.
[0091] The above embodiments have concentrated on utilizing tilting
to vary the polar axis of the permanent magnet(s) to vary the path
of the resulting magnetic flux. Some exemplary embodiments that
utilize rotation will now be described. It is noted that in some
embodiments, both rotation and tilting can be utilized to vary the
polar axis of the permanent magnet, and thus vary the path of the
resulting magnetic flux.
[0092] It is noted that while the embodiment detailed above utilize
an external magnet assembly that is movable and an implantable
magnet assembly that is immovable (after implantation), in an
alternate embodiment, the external magnet assembly is fixed
(relative to the global geometry of the external component) and the
implantable magnet assembly is configured to move (relative to the
global geometry of the implantable component) according to one or
more or all of the movement capabilities of the external magnet
assembly detailed herein (or others--again, the movements of the
external magnet assembly are not limited to those detailed herein
providing that the flux path can be varied in accordance with the
teachings detailed herein) so as to vary the path of the magnetic
flux. In an exemplary embodiment, any movement regime of the
external magnet assembly is applicable to the internal magnet
assembly provided that such varies the path of the magnetic flux.
Still further, in an exemplary embodiment, both the external
component and the implantable component are configured such that
their respective magnet assemblies move relative to the global
structure thereof, providing that such varies the path of the
magnetic flux such that the utilitarian teachings associated
therewith as detailed herein result.
[0093] Referring now to FIG. 8 there is an alternate embodiment.
Briefly, this embodiment utilizes a dual pole system, where the
implantable component includes two separate permanent magnets. This
will be described in detail below. It is noted however, that just
as the embodiments detailed above can be practiced utilizing an
implantable component having two or more separate permanent
magnets, the embodiments below can be utilized with an implantable
components having only one permanent magnet.
[0094] FIG. 8 depicts a schematic of an exemplary bone conduction
device 800A corresponding to bone conduction device 300 of FIG. 2.
The exemplary bone conduction device 800A of FIG. 8 includes an
external component 840A corresponding to external component 340 of
FIG. 2, and an implantable component 850A corresponding to
implantable component 350 of FIG. 2.
[0095] The external component 840A is somewhat different than those
detailed above beyond simple fact that the type of permanent
magnets used therein are different. Briefly, the permanent magnets
that generate, at least in part, the magnetic flux that is utilized
to retain the external component 840A to the recipient are located
to the sides of transducer 342A, as opposed to between the
transducer 342A and the skin of the recipient/skin interface
surface 891 of the external component 840A. In an exemplary
embodiment of this exemplary embodiment, at least some of the
magnets are rotated in a plane parallel with the axis of the
attraction force, to vary the attraction force. Instead of the
external component 840A being configured such that at least some of
the magnets tilt relative to the longitudinal axis 390 of the bone
conduction device 800A, at least some of the magnets are
adjustable/rotatable about an axis (990 as seen in FIGS. 9A-9B,
discussed below) that is perpendicular to the longitudinal axis 390
and extends through the magnets of the external magnet assembly of
the external component. That is, instead of the magnets being
tiltable relative to the external component 840A of the bone
conduction device, the magnets are adjustable locally (the magnets
basically occupy the exact same space within the external component
840A, but their orientation in that space can be changed). That
said, it is noted that other embodiments can utilize both tilting
and rotation to change the orientation of the polar axis of at
least some magnets. Any movement or adjustment of the location of
magnets that will enable the teachings detailed herein and/or
variations thereof to be practiced can be utilized in at least some
embodiments.
[0096] In an exemplary embodiment, external component 840A has the
functionality of a transducer/actuator, irrespective of whether it
is used with implantable component 850A. The external component
840A includes a vibrating actuator represented in black-box format
by reference numeral 342A. Any type of actuator that can enable the
teachings detailed herein and/or variations thereof to be practiced
can be utilized in at least some exemplary embodiments.
[0097] External component 840A includes an external magnet assembly
that includes permanent magnets having a North-South alignment.
These magnets are rotationally adjustable relative to the position
of the respective pole axes, as will be detailed below. However, in
the configuration depicted in FIG. 8 (without adjustment as will be
detailed below), the magnet on one side of the magnetic assembly,
relative to the longitudinal axis 390 of the bone conduction device
800A, has the North pole facing away from the skin of the
recipient, and the magnet on the other side of the magnetic
assembly relative to longitudinal axis 390 of the bone conduction
device all have North poles facing towards the skin of the
recipient. That is, the North-South alignment of one side of the
external magnet assembly is opposite that of the other side of the
assembly. However, exemplary embodiments of the external component
840A are configured such that the individual magnets can be moved
so that the poles are different than that depicted in FIG. 8.
[0098] The external component 840A includes a bottom surface 891
relative to the frame of reference of FIG. 3) that is configured to
interface with the exterior skin of the recipient. In this regard,
the bottom of the external component 840A corresponds to plate 346
of FIG. 2 as described above. It is through surface 891 that
vibrations generated by the electromagnetic actuator of the
external component 840A are transferred from the external component
340A to the skin of the recipient to evoke a hearing percept.
[0099] The external magnet assembly of external component 840A
comprises two (2) different magnets, each arrayed on opposite sides
of the longitudinal axis 390. (It is noted that in alternative
embodiments, more magnets can be used, as will be detailed below).
This is also the case with respect to the embodiments detailed
above and any other embodiment, providing that the teachings
detailed herein and/or variations thereof can be practiced.) As can
be seen, there is a magnet 858A and a magnet 858B (these are
circular disk magnets--more on this below). As will be detailed
more thoroughly below, one or both of the permanent magnets are
configured to rotate so as to vary the path of the magnetic flux
generated by the external magnet assembly as a result of adjustment
of the alignment of the polar axes. In this regard, in at least
some exemplary embodiments, during operational use of the bone
conduction device 800A, the magnets of the external magnet assembly
are aligned with the magnets of the implantable magnet assembly
such that the poles of the permanent magnets 858A, 858C have a
North-South alignment in exactly the same direction and the poles
of the permanent magnets 858B, 858D have a North-South alignment in
the same direction (but opposite of that of magnets 858A and 858C)
in a scenario where maximum attractive force between the external
component 840A and the implantable component 350A is desired.
Conversely, in at least some exemplary embodiments, during
operational use of the bone conduction device 800A, the magnets of
the external magnet assembly are aligned with the magnets of the
implantable magnet assembly such that the poles of the permanent
magnet 858A are aligned in a different direction than that of
magnet 858C due to the adjustability of the relative position of
the magnets 858A. Furthermore, in this exemplary embodiment, during
operational use of the bone conduction device 800A, the magnets of
the external magnet assembly are aligned with the magnets of the
implantable magnet assembly such that the poles of the permanent
magnets 858B are aligned in a different direction than that of
magnet 358D because of the adjustability of the relative position
of the magnet 858B. (It is also noted that the above North-South
pole arrangement can be utilized for the tilting magnet assembly of
FIG. 6, where the implantable component is a dual pole system.
[0100] The above adjustability can be conceptually seen in FIG.
9A-B, which conceptually depicts isometric views of the magnets
858A and 858B of the bone conduction device 800A at various
orientations relative to one another. More specifically, FIG. 9A
depicts a configuration of the magnets of the external magnet
assembly and the implantable magnet assembly such that the maximum
attraction force between the external component 840A and 350A is
achieved. Briefly, with respect to the frame of reference of FIG.
9A, the plane 899 corresponds to the plane of FIG. 8, wherein the
plane 899 lies on the longitudinal axis 390 of the bone conduction
device 800A.
[0101] As can be seen in FIG. 9A, the magnets of the external
component are segmented into 2 magnets, both of which are disk
shaped. Briefly, it is noted that in at least some embodiments, the
configurations of magnets 858A and 858B can be different (box
shaped, bar magnets, etc.--any arrangement that can enable the
teachings detailed herein and/or variations thereof to be practiced
can be utilized).
[0102] In embodiments corresponding to FIGS. 9A-9B, the external
component 840A is configured such that one or more of the magnets
858A and 858B can be moved to have a different angular
configuration with respect to the pole alignment. Accordingly, FIG.
9B depicts the magnets shifted by an angle of about 30 degrees
(magnet 858B being rotated about axis 990 in the direction of arrow
9B relative to the location of that magnet depicted in FIG. 9A, and
magnet 858A being rotated about axis 990 in the direction of arrow
9A relative to the location of the magnet depicted in FIG. 9A.
Thus, these magnets have an angular offset of 30 degrees relative
to the positions they were in as depicted in FIG. 9A.
[0103] It is noted that in an alternate embodiment, the magnets are
rotated in the same direction about axis 990. It is further noted
that while the embodiments depicted in the figures herein are
depicted as having rotations that are of the same amount, in an
alternate embodiment, the angular rotation can be different for one
or more magnets relative to one or more other magnets (either in
the same direction or the alternate direction).
[0104] FIG. 9C depicts an alternate embodiment where the magnets
858A and 858B are tiltable, and FIG. 9D depicts an alternate
embodiment where the magnets are both tiltable and rotatable. In
both embodiments, the tilting and rotation vary the path of the
resulting magnetic flux.
[0105] FIG. 10 depicts a quasi-functional diagram of a
cross-section of the external and implantable magnet assemblies
taken through the plane of FIG. 8 with the magnets in the
arrangement as presented in FIG. 9A, with the magnetic flux
following a magnetic flux path 1000A. FIG. 10 depicts an air gap
AG10, representing the space between the external magnet assembly
858EX and the implantable magnet assembly 858IM.
[0106] As can be seen, in an exemplary embodiment, the magnetic
flux path 1000A travels in a circuit through all of the magnets of
the external magnet assembly and the implantable magnet assembly.
Arrows 1011 depict the relative localized strength of the magnetic
flux and the direction thereof in between the magnets of the
external magnet assembly 858EX and the implantable magnet assembly
858IM (the strength and direction of the magnetic flux at those
local locations within the air gap AG10). With respect to the
cross-sectional view of FIG. 10, the magnetic flux travels in a
counterclockwise direction, as is represented by arrows 1011,
consistent with the fact that all of the poles of the magnets are
aligned. That said, if the view of FIG. 10 was presented from the
opposite side of the longitudinal axis 390, the direction of the
magnetic flux would be clockwise. Alternatively, if all of the
magnetic poles were reversed from that seen in the figures, the
magnetic flux would be in the opposite direction. Any direction of
magnetic flux that will enable the teachings detailed herein and/or
variations thereof to be practiced can be utilized in at least some
embodiments.
[0107] FIG. 11A depicts a view looking right in the plane of FIG.
10 (a side view of the views of FIGS. 10 and 8). Here, the magnetic
flux is represented as a plane, line 1000A lying in the plane. To
be clear, in these embodiments, the magnetic flux does not lie only
in a plane. However, these figures are presented for conceptual
purposes so as to better explain the general phenomenon associated
with these embodiments. As can be seen, the plane in which the
magnetic flux lies (line 1000A) is a vertical line that passes
through the centers of the magnets 858B and 858D, owing to the fact
that the poles of the magnets are aligned in the vertical
direction. Conceptually speaking, the view of FIG. 11A represents
the fact that the magnetic flux between the magnet 858B and 858D is
generally vertical, as represented by the vertical line 1000A.
[0108] FIG. 11B conceptually represents what happens to the
magnetic flux path when the magnet 858B is rotated such that the
poles no longer align with the poles of magnet 858D. As can be
seen, the flux path represented by line 1000A is angled relative to
the vertical/relative to the longitudinal axis 390. FIG. 11B
conceptually depicts the influence on the magnetic flux of magnet
858D. In this regard, as can be seen, line 1000A is not perfectly
aligned with the North-South polar axis, but instead is located at
an angle thereto. Again this is conceptual. The point is that the
rotation of the magnet 858B changes the magnetic flux path. The
changes in the magnetic flux path result in a change in the
retention force/attraction force between the external magnet
assembly 858EX and the implantable magnet assembly 858IM. Here, the
more that the magnet 858B is rotated from the original orientation
of the poles of FIG. 11A, the greater the reduction in the magnetic
force attraction between the external component and the implantable
component. In the embodiment depicted in FIG. 11B, the magnets of
the external magnet assembly 858EX are both rotated in the same
direction, and thus the path is moved in the same plane,
conceptually speaking. FIG. 11C depicts the alternate scenario
where the magnets of the external magnet assembly 858EX are rotated
in different directions. The resulting magnetic flux path takes on
the form of a piece of twisted rectangular cardboard, again,
conceptually speaking (where the view of FIG. 11C is looking down
the length of the flexed cardboard, where the thicker line 1000A
represents the end of the piece of cardboard closest to the viewer,
and the thinner line 1000A represents the end of the piece of
cardboard furthest from the viewer).
[0109] In FIGS. 11A-11C, the shortened length of arrow 1011
represents the weakened retention force resulting from the movement
of the path of the magnetic flux.
[0110] In at least some exemplary embodiments, the bone conduction
device is configured such that when the implantable component
interacts with the magnetic flux of the external component to
establish retention of the external component to the recipient, a
torque applied to skin of the recipient is substantially constant
through a substantial range of adjustments of the path of the
generated magnetic flux. In at least some exemplary embodiments,
this is achieved by utilizing the two pole magnet system (e.g.,
where the implant has two or more magnets and the external
component includes two or more magnets). In this regard, in at
least some exemplary embodiments of the embodiment of FIG. 3, the
tilting of the external magnet assembly 358EX can impart a torque
onto the skin of the recipient because there is a stronger
attraction on one side of the other side of the external component
owing to the movement of the path of the magnetic flux. This torque
could result in the shifting of the orientation of the external
component relative to the implantable. This could have a
deleterious effect respect to the use of the teachings detailed
herein with a transcutaneous coil, such as an inductance coil, such
as may be used in the case of a cochlear implant, or the like. This
could potentially cause misalignment between the coils that are
implanted in the recipient and the coils of the external component.
Accordingly, in an exemplary embodiment, utilizing a plurality of
magnets with orientations that are all adjustable/magnets that are
all tiltable can be utilized to counteract the resulting imbalance
in the forces, thus preventing the development of the
aforementioned torque.
[0111] It is noted that the aforementioned torque applied to the
skin that is prevented from being applied in at least some
exemplary embodiments, exists both with respect to torque applied
about an axis normal to the skin of the recipient and applied about
axis that is parallel to and lying on the skin of the recipient,
while in other exemplary embodiments, it exists on one and not the
other (about the normal axis or about the parallel axis).
[0112] FIG. 12 presents another alternate embodiment utilizing
magnet pairs. This exemplary embodiment has utilitarian value in
that the magnet pairs counteract any imbalance in the force that
results from the rotation of the magnets, thus preventing the
aforementioned torque from being applied to the skin of the
recipient/improving the likelihood that the external component will
remain aligned with the implantable component.
[0113] More specifically, FIG. 12 depicts a schematic of an
exemplary bone conduction device 1200A corresponding to bone
conduction device 300 of FIG. 2. In this exemplary embodiment, the
implantable component 350A of bone conduction device 1200A is the
same as that of the bone conduction device 800A. Conversely, the
external component 1240A has a different configuration than that of
external component 840A. Briefly, four permanent magnets that
generate, at least in part, the magnetic flux that is utilized to
retain the external component 1240A to the recipient are located to
the sides of transducer 342A. In an exemplary embodiment of this
exemplary embodiment, at least some of the magnets are rotated in a
plane parallel with the axis of the attraction force, to vary the
path of the magnetic flux and thus vary the attraction force. At
least some of the magnets are adjustable/rotatable about an axis
(990 as seen in FIGS. 13A-13B, discussed below) that is
perpendicular to the longitudinal axis 390 and extends through the
magnets of the external magnet assembly.
[0114] External component 1240A includes an external magnet
assembly that includes permanent magnets having a North-South
alignment. These magnets are locationally adjustable relative to
one another, as will be detailed below. However, in the
configuration depicted in FIG. 12 (without adjustment), the magnets
on one side of the magnetic assembly, relative to the longitudinal
axis 390 of the bone conduction device 300A, all have North poles
facing away from the skin of the recipient, and the magnets on the
other side of the magnetic assembly relative to longitudinal axis
390 of the bone conduction device all have North poles facing
towards the skin of the recipient. That is, the North-South
alignment of one side of the external magnet assembly is opposite
that of the other side of the assembly. However, exemplary
embodiments of the external component 1240A are configured such
that the individual magnets can be moved so that the poles are
different than that depicted in FIG. 12.
[0115] The external magnetic assembly of external component 1240A
comprises four (4) different magnets arrayed on opposite sides of
the longitudinal axis 390 in two sets. (It is noted that in
alternative embodiments, more magnets can be used). The first set
includes outer permanent magnet 1258AO and inner permanent magnet
1258AI. The second set includes outer permanent magnet 1258BO and
inner permanent magnet 1258BI. As will be detailed more thoroughly
below, one or both of the outer permanent magnets of these sets are
configured to be moveable relative to the inner permanent magnets
of the sets, and/or visa-versa, so as to vary the path of the
magnetic flux generated by the external magnetic assembly as a
result of the polar axis being shifted. In this regard, in at least
some exemplary embodiments, during operational use of the bone
conduction device 1200A, the magnets of the external magnet
assembly are aligned with the magnets of the implantable magnet
assembly such that the poles of the permanent magnets 1258AO,
1258AI and 858C have a North-South alignment in exactly the same
direction, and the poles of the permanent magnets 1258BO, 1258BI
and 858D have a North-South alignment in the same direction (but
opposite of that of magnets 1258AO, 1258AI and 858C) in a scenario
where maximum attractive force between the external component 840A
and the implantable component 850A is desired. Conversely, in at
least some exemplary embodiments, during operational use of the
bone conduction device 1200A, the magnets of the external magnet
assembly are aligned with the magnets of the implantable magnet
assembly such that the poles of the permanent magnets 1258AO and/or
1258AI are aligned in a different direction than that of magnet
858C due to the adjustability of the relative position of the
magnets 1258AO and/or 1258AI. Furthermore, in this exemplary
embodiment, during operational use of the bone conduction device
1200A, the magnets of the external magnet assembly are aligned with
the magnets of the implantable magnet assembly such that the poles
of the permanent magnets 858BO and/or 858BI are aligned in a
different direction than that of magnet 858D because of the
adjustability of the relative position of the magnets 1258BO and/or
1258BI.
[0116] The above adjustability can be conceptually seen in FIGS.
13A-B, which conceptually depict isometric views of the 1258AI,
12858AO, 1258BI and 12858BO magnets of the bone conduction device
1200A at various orientations relative to one another. More
specifically, FIG. 13A depicts a configuration of the magnets of
the external magnet assembly such that the maximum attraction force
between the external component 1240A and 850A is achieved.
[0117] As can be seen in FIG. 13A, the magnets of the external
component are segmented into two magnets, both of which are disk
shaped. Briefly, it is noted that in at least some embodiments, the
configurations of magnets 1258AI and 1258AO corresponds to that of
1258BI and 1258BO, respectively, except the orientation relative to
one another and relative to the longitudinal axis is reversed
(1258AO is on the outside, and the South poles of both magnets
1258AI and 1258AO are located on the top (facing away from the
skin). While disk magnets are depicted in the embodiment of FIG.
12, in alternative embodiments, box magnets and/or bar magnets can
be used, totality or in combination with other types.
[0118] In embodiments corresponding to FIGS. 13A-13B, the external
component 1240A is configured such that one or more of the outer
magnets 1258AO and 1258BO can be moved to have a different angular
configuration relative to the inner magnets 1258AI and 1258BI (or
visa-versa, or both can be moved in some other embodiments).
Accordingly, FIG. 13B depicts the outer magnet 1258BO shifted by an
angle 20 degrees in the direction of arrow 13A relative to the
location of those magnets depicted in FIG. 13A, and inner magnet
1258BI shifted by an angle 20.degree. in the direction of arrow
13B. (Not shown in FIG. 13B is outer magnet 1258AO shifted in the
direction of angle 12A and inner magnet 1258AI shifted in the
direction of angle 12B).
[0119] FIG. 14A conceptually represents the magnetic flux as seen
looking from the side of the orientation of FIG. 12 (FIG. 14A
corresponds to the view of FIG. 11A detailed above). Arrow 1411
represents the strength of the resulting magnetic flux where the
poles of the magnets of the external magnet assembly 1258EX are all
aligned with those of the implantable magnet assembly 858IM. FIG.
14B conceptually represents the magnetic flux as seen from the side
of the orientation of FIG. 12, except with the permanent magnets
are rotated according to that depicted in FIG. 13B. Line 1401
corresponds to the portion of the magnetic flux that is most
influenced by magnet 1259BO (shown), and line 1402 corresponds to
the portion of the magnetic flux that is most influenced by magnet
1258BI (eclipsed by magnet 1259BO). Arrow 1411 represents the
weakening of the attraction force between the external component
and the implantable component resulting from the varying of the
magnetic flux path that results from rotation of the permanent
magnet of the external component. As can be seen, the arrow 1411 in
FIG. 14B is aligned with the axis 390, thus conceptually
representing the lack of torque resulting from the rotation of the
magnets.
[0120] FIG. 15A depicts an exemplary embodiment where the external
component includes an external magnet assembly 1558EX including
four (4) permanent magnets arrayed symmetrically about the
longitudinal axis 390 of the external component in 2 dimensions (as
opposed to the 1 dimension of FIG. 12). In an exemplary embodiment,
this configuration also prevents the development of the
aforementioned torque/aids in preventing misalignment between the
external component implantable component. In this exemplary
embodiment, a single pole implantable magnet assembly 358IM is used
(the implantable component is the same as that of the embodiment of
FIG. 3 above).
[0121] FIG. 15B schematically depicts rotation of the permanent
magnets of the external magnet assembly 1558EX in a manner that
results in a balance/symmetrical force distribution about axis 390,
albeit one that has a reduced retention force relative to that
which is the case with the magnets aligned as shown in FIG. 15A
only to movement of the path of the magnetic flux. It is noted that
in alternative embodiment, instead of rotation, the permanent
magnets of the external magnet assembly 1558EX can tilt to change
the path of the magnetic flux, and thus reduce the strength of the
resulting attraction between the external component and the
implantable component. Still further, in an exemplary embodiment,
the permanent magnets of the external magnet assembly 1558EX can
tilt and rotate to change the path of the magnetic flux, and the
vary the force of the attraction between the external component and
the implantable component.
[0122] In an exemplary embodiment, the permanent magnets of the
external magnet assembly 1558EX are mechanically linked such that
all magnets rotate and/or tilt by the same amount, albeit some in
different directions. In an exemplary embodiment, the magnets of
the external magnet assembly interact with a shaft having teeth are
utilized to rotate and/or tilt the magnets by moving the shaft up
and down. Alternatively, the shift can be aligned horizontally such
that moving the shaft and the horizontal plane rotate and/or tilt
the magnet. A rack and pinion system can be utilized. Alternatively
and/or in addition to this, an electromagnetic actuator can be
utilized. In some embodiments, each individual magnet can be
rotated/tilted independently of the others. Any device, system
and/or method that can enable rotation and/or tilting of the
permanent magnets that can enable the teachings detailed herein
and/or variations thereof to be practiced can be utilized in at
least some embodiments.
[0123] It is noted that while FIG. 15A depicts four (4) magnets of
the external magnet assembly 1558EX, in an alternate embodiment,
three (3) magnets are utilized. Any arrangement that will enable
force balance/the elimination of torque (about various axes as
detailed herein) can be utilized in at least some embodiments. For
example, while the magnets of 1558EX are arrayed about axis 390 in
a equidistant manner (approximately 90 degrees), with the flat
faces thereof parallel to one another, in an alternate embodiment,
the magnets of 1558 EX (three or four) can be arrayed as seen in
FIGS. 15C and 15D, which is a view looking downward along axis 390
(FIG. 15C showing a 3 magnet configuration, and FIG. 15D showing a
4 magnet configuration), with the magnets rotated at a somewhat
extreme angle (for purposes of illustration only) relative to a
North-South pole alignment parallel to axis 390.
[0124] In view of the above, in an exemplary embodiment, there is
an external component of a medical device, comprising a first
permanent magnet having a first polarity axis, wherein the external
component is configured such that the first permanent magnet
contributes to the resulting magnetic retention force so as to at
least partially removably retain, via the resulting magnetic
retention force, the external component to a recipient thereof. The
external component of the medical device comprises a second
permanent magnet having a second polarity axis, wherein the
external component is configured such that the second permanent
magnet contributes to the resulting magnetic retention force so as
to at least partially removably retain, via the resulting magnetic
retention force, the external component to a recipient thereof. The
external component is configured to enable the adjustment of an
orientation of the second polarity axis. The external component of
the medical device includes a third permanent magnet having a third
polarity axis, wherein the external component is configured such
that the third permanent magnet contributes to the resulting
magnetic retention force so as to at least partially removably
retain, via the resulting magnetic retention force, the external
component to a recipient thereof. The external component is
configured to enable the adjustment of an orientation of the third
polarity axis. The external component of the medical device
includes a fourth permanent magnet having a fourth polarity axis,
wherein the external component is configured such that the fourth
permanent magnet contributes to the resulting magnetic retention
force so as to at least partially removably retain, via the
resulting magnetic retention force, the external component to a
recipient thereof, and the external component is configured to
enable the adjustment of an orientation of the fourth polarity
axis.
[0125] In an exemplary embodiment, there is a medical device as
detailed herein, wherein the device is configured such that a
resulting magnetic flux of the external component establishing the
resulting magnetic retention force is substantially symmetrical
about a plane parallel to a longitudinal axis of the external
component throughout a range of orientations of the polar axes of
the first, second third and fourth permanent magnets. Still further
in an exemplary embodiment, the medical device configured such that
a resulting magnetic flux of the external component establishing
the resulting magnetic retention force is substantially symmetrical
about the longitudinal axis of the external component throughout a
range of orientations of the polar axes of the first, second,
third, and fourth permanent magnets.
[0126] Embodiments include methods of using the medical devices
detailed herein. For example, referring now to FIG. 16, there is an
exemplary flowchart 1600 for an exemplary method. Method 1600
includes method action 1610, which entails the action of obtaining
an external component of a medical device (e.g., 340A, 840A, 1240A,
etc.) configured to be magnetically retained against outer skin of
a recipient via a magnetic coupling between the external component
and an implanted component (e.g. 350A, 850A, etc.) in the
recipient. Method 1600 further includes method action 1610, which
entails adjusting a path of a magnetic flux generated by the
external component such that the resulting retention force of the
magnetic retention for the recipient is varied from that which was
the case prior to the adjustment. In an exemplary embodiment, this
adjustment of the path of the magnetic flux results from tilting
and/or rotation of the magnets as detailed herein and/or variations
thereof.
[0127] In an exemplary embodiment, the aforementioned method
further includes placing the external component against a
recipient's skin at least one of after or during adjusting the
path, such that the external component is retained against the skin
of the recipient via the magnetic coupling between the external
component and the implanted component, wherein the implanted
component includes a magnet arrangement having a single polarity
axis, and the magnetic coupling results in substantially no torque
on the external component while positioned against the skin of the
recipient in the absence of external forces on the external
component.
[0128] In an exemplary embodiment, there is a method that includes
placing the external component against a recipient's skin at least
one of after or during adjusting the path of the magnetic flux such
that the external component is retained against the skin of the
recipient via the magnetic coupling between the external component
and the implanted component, wherein the implanted component
includes a magnet arrangement having a single polarity axis, and
the resulting magnetic flux of the magnetic flux generated by the
external component and the magnet of the implanted component is
symmetrical about a plane parallel to and lying on the single
polarity axis.
[0129] In an exemplary embodiment, there is a method that includes
placing the external component against a recipient's skin at least
one of during or after adjusting the path such that the external
component is retained against the skin of the recipient via the
magnetic coupling between the external component and the implanted
component, wherein the implanted component includes a magnet
arrangement having multiple polarity axes, and the resulting
magnetic field of the magnetic flux generated by the external
component and the implanted component is symmetrical about a plane
parallel to and lying in between respective axes of the multiple
polarity axes.
[0130] Still further, in at least some embodiments, the action of
adjusting the orientation of the polar axes of one or more magnets
of the external component such that the resulting retention force
is varied due to a variation in the path of the magnetic flux is
executed without changing a total magnetic density of permanent
magnets of the external component. In at least some embodiments,
the action of adjusting the orientation of one or more polarity
axes of the magnets of the external component such that the
resulting retention force is varied is executed without removing or
adding any magnets to the external component and/or the action of
adjusting the orientation of one or more of the polar axes of the
magnets of the external component is executed without directly
accessing the one or more magnets from outside the external
component.
[0131] Also, it is noted that while the embodiments detailed above
are directed towards an arrangement where the external component
includes the adjustable magnet arrangement, in at least some
alternate embodiments, the implantable component can include the
adjustable magnets. That is, in at least some embodiments, any one
or more or all of the teachings detailed herein are applicable to
the implantable component(s) detailed herein. It is further noted
that in some embodiments, both the implantable component and the
external component can utilize the adjustable features detailed
herein.
[0132] In an exemplary embodiment, the implanted magnets can be
hermetically sealed within an implantable housing. In some
embodiments, a magnetic field can be utilized to adjust the
location of the magnets. Alternatively and/or in addition to this,
an invasive surgical procedure can be utilized, albeit a limited
one. In an exemplary embodiment, the procedure can be of limited
invasivity such that a local anesthesia need only be utilized (if
at all). For example, a needle can be inserted through the skin to
contact the implant and push and/or pull a portion of the implanted
component, thereby moving the magnet(s). Alternatively, a puncture
can be made in the skin, and a thin rod or the like can be inserted
through the puncture to apply the tensile and/or compressive force
to the implantable component so as to move the magnet(s). An
exemplary embodiment can include a lock that can be disabled and
enabled with the needle/rod, which permits and prevents,
respectively, movement of the magnet(s).
[0133] It is noted that any disclosure of any device detailed
herein corresponds to a disclosure of a method of making that
device and a method of utilizing the device. It is further noted
that any disclosure of any method detailed herein corresponds to a
disclosure of a device utilized to execute that method. Any feature
of any embodiment detailed herein can be combined with any other
feature of any other embodiment detailed herein unless otherwise
specified.
[0134] While various embodiments 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.
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