U.S. patent application number 13/380339 was filed with the patent office on 2012-08-02 for instrument for inserting implantable electrode carrier.
This patent application is currently assigned to MED-EL ELEKTROMEDIZINISCHE GERAETE GMBH. Invention is credited to Karl-Bernd Huttenbrink, Claude Jolly, Eckhard Schulz, Daniel Sieber, Martin Zimmerling.
Application Number | 20120197265 13/380339 |
Document ID | / |
Family ID | 42691176 |
Filed Date | 2012-08-02 |
United States Patent
Application |
20120197265 |
Kind Code |
A1 |
Sieber; Daniel ; et
al. |
August 2, 2012 |
Instrument for Inserting Implantable Electrode Carrier
Abstract
A surgical instrument for inserting an implantable electrode
carrier includes a housing having a proximal end and a distal end.
The proximal end is configured to hold the implantable electrode
carrier. The instrument also includes a vibration generator
positioned within the housing. The vibration generator is
configured to generate vibrations in at least a portion of the
electrode carrier.
Inventors: |
Sieber; Daniel; (Innsbruck,
AT) ; Zimmerling; Martin; (Patsch, AT) ;
Jolly; Claude; (Innsbruck, AT) ; Schulz; Eckhard;
(Starnberg, DE) ; Huttenbrink; Karl-Bernd;
(Dresden, DE) |
Assignee: |
MED-EL ELEKTROMEDIZINISCHE GERAETE
GMBH
Innsbruck
AT
|
Family ID: |
42691176 |
Appl. No.: |
13/380339 |
Filed: |
June 25, 2010 |
PCT Filed: |
June 25, 2010 |
PCT NO: |
PCT/US10/39988 |
371 Date: |
April 4, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61220630 |
Jun 26, 2009 |
|
|
|
Current U.S.
Class: |
606/129 |
Current CPC
Class: |
A61N 1/0541
20130101 |
Class at
Publication: |
606/129 |
International
Class: |
A61B 17/00 20060101
A61B017/00 |
Claims
1. A surgical instrument for inserting an implantable electrode
carrier, the instrument comprising: a housing having a proximal end
and a distal end, the proximal end configured to hold the
implantable electrode carrier and the distal end configured to
allow a surgeon to grip the housing; and a vibration generator
positioned within the housing, the vibration generator configured
to generate vibrations in at least a portion of the electrode
carrier.
2. The instrument of claim 1, wherein the vibration generator is
positioned within the distal end of the housing, the proximal end
of the housing, or both.
3. The instrument of claim 1, further comprising a power supply
coupled to the vibration generator and positioned within the
housing, the power supply configured to supply energy to the
vibration generator.
4. The instrument of claim 3, wherein the power supply is
positioned within the distal end of the housing.
5. The instrument of claim 1, wherein the vibration generator
includes a floating mass transducer.
6. The instrument of claim 5, wherein the floating mass transducer
comprises: a bushing having an inner area; a permanent magnet
positioned within the inner area of the bushing; and an
electromagnetic coil adjacent to a portion of the bushing, the
electromagnetic coil configured to move the permanent magnet within
the inner area of the bushing.
7. The instrument of claim 6, wherein the floating mass transducer
further includes at least one spring positioned between the
permanent magnet and one end of the bushing so that the at least
one spring is configured to move the permanent magnet back to a
neutral position after the electromagnetic coil moves the permanent
magnet within the inner area of the bushing.
8. The instrument of claim 6, wherein the permanent magnet is
cylindrical or spherical in shape.
9. The instrument of claim 1, wherein the vibration generator
includes an electromotor connected to a gear, and a mass connected
to the gear, wherein the mass is configured to produce at least a
portion of the vibrations generated by the vibration generator when
the gear moves the mass.
10. The instrument of claim 1, wherein the vibration generator
includes an electromotor connected to a gear having an unbalanced
mass, wherein the unbalanced mass is configured to produce at least
a portion of the vibrations generated by the vibration generator
when the gear moves the unbalanced mass.
11. The instrument of claim 1, further comprising one or more
sensors positioned near the distal end of the housing, the one or
more sensors configured to sense a force applied to the instrument,
wherein the vibration generator is configured to control vibration
parameters based on the sensed force.
12. The instrument of claim 1, wherein the vibration generator
imparts longitudinal oscillations, transverse oscillations,
rotational oscillations, or a combination thereof, to the proximal
end of the housing.
13. The instrument of claim 1, wherein the vibration generator
includes a piezoelectric actuator, a pneumatic actuator, an
hydraulic actuator, an electrodynamic actuator, a mechanical
actuator, or a combination thereof.
14. The instrument of claim 1, wherein the housing has a
longitudinal axis from the proximal end to the distal end of the
housing, and the vibration generator is concentric to the
longitudinal axis.
15. The instrument of claim 1, wherein the housing has a
longitudinal axis from the proximal end to the distal end of the
housing, and the vibration generator is offset from the
longitudinal axis.
16. A method of making a surgical instrument for inserting an
implantable electrode carrier, the method comprising: providing a
housing having a proximal end and a distal end, the proximal end
configured to hold the implantable electrode carrier and the distal
end configured to allow a surgeon to grip the housing; and
positioning a vibration generator within the housing, the vibration
generator configured to generate vibrations in at least a portion
of the electrode carrier.
17. The method of claim 16, further comprising: providing a power
supply coupled to the vibration generator and positioned within the
housing, the power supply configured to supply energy to the
vibration generator.
18. The method of claim 16, wherein the vibration generator
includes a floating mass transducer comprising: a bushing having an
inner area; a permanent magnet positioned within the inner area of
the bushing; and an electromagnetic coil adjacent to a portion of
the bushing, the electromagnetic coil configured to move the
permanent magnet within the inner area of the bushing.
19. The method of claim 16, wherein the vibration generator
includes an electromotor connected to a gear, and a mass connected
to the gear, wherein the mass is configured to produce at least a
portion of the vibrations generated by the vibration generator when
the gear moves the mass.
20. The method of claim 16, wherein the vibration generator
includes an electromotor connected to a gear having an unbalanced
mass, wherein the unbalanced mass is configured to produce at least
a portion of the vibrations generated by the vibration generator
when the gear moves the unbalanced mass.
21. The method of claim 16, further comprising: providing one or
more sensors positioned near the distal end of the housing, the one
or more sensors configured to sense a force applied to the
instrument, wherein the vibration generator is configured to
control vibration parameters based on the sensed force.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 61/220,630 filed Jun. 26, 2009, the
disclosure of which is incorporated by reference herein in its
entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to surgical
instruments for medical implants and, more particularly, the
invention relates to surgical instruments for implantable electrode
carriers that improve the insertion process of the electrode
carriers.
BACKGROUND OF THE INVENTION
[0003] For many patients with severe to profound hearing
impairment, there are several types of middle-ear and inner-ear
implants that can restore a sense of partial or full hearing. For
example, cochlear implants can restore some sense of hearing by
direct electrical stimulation of the neural tissue of the inner ear
or cochlea. The cochlear implant typically includes an electrode
carrier having an electrode lead and an electrode array, which is
threaded into the cochlea. The electrode array usually includes
multiple electrodes on its surface that electrically stimulate
auditory nerve tissue with small currents delivered by the
electrodes distributed along the electrode array. These electrodes
are typically located toward the end of the electrode carrier and
are in electrical communication with an electronics module that
produces an electrical stimulation signal for the implanted
electrodes to stimulate the cochlea.
[0004] One of the important steps in cochlear implant surgery is
the insertion of the electrode array into the scala tympani of the
cochlea. In some cases, this insertion process can be disrupted
when the continuous movement of the electrode carrier into the
cochlea gets disturbed due to increased frictional forces between
the cochlea wall and the electrode array, or due to small obstacles
preventing the electrode carrier from smoothly moving along the
insertion path. In both cases, the electrode carrier may become
damaged if it is excessively bent when being pushed further inside
the cochlea while the tip or other parts of the electrode carrier
are prevented from moving forward. Furthermore, x-ray microscopy
studies by Huttenbrink et al. allowed a visualization of the
frictional behaviour of electrodes in the inner ear and revealed
that in some cases there might be the danger of kinking of the
electrode carrier inside of the scala tympani. A subsequent contact
pressure between electrode and basilar membrane which may lead to
rupture of the basilar membrane is very likely to damage anatomical
structures of the inner ear and destroy residual hearing. Such
damage is not acceptable with the latest trends in Electric
Acoustic Stimulation (EAS) technology and cochlear implant surgery
to preserve any residual hearing.
[0005] To minimize these problems, lubricating substances are
sometimes used on the electrode carrier to reduce the frictional
forces between electrode carrier and the cochlea. However, it is
questionable whether these lubricating substances are able to
prevent typically occurring problems during the insertion process
and currently have not become a commonly accepted clinical
practice.
[0006] Another issue which is observed in cochlear implant surgery
is the floppiness of the electrode carrier in the mastoidectomy and
posterior tympanatomy which may make it difficult to guide the
electrode carrier to the cochleostomy or round window without
picking up blood or other fluids from the surrounding tissues. A
contamination of the electrode carrier with blood represents
another potential hazard to the residual hearing of patients.
[0007] U.S. Patent Application Publication No. 2007/0225787 to
Simaan et. al. ("Simaan") teaches active-bending electrodes and
corresponding insertion systems for inserting same. In this
context, an electrode applicator is mentioned which reduces the
frictional forces as the electrode traverses the inner ear by
applying vibrations to the electrode array. However, the insertion
systems disclosed therein include a controller located remotely,
making the systems bigger and more unwieldy. In addition, Simaan
fails to provide any teachings on how, and by what mechanism, the
insertion system generates the vibrations in the electrode
array.
SUMMARY OF THE INVENTION
[0008] In accordance with one embodiment of the invention, a
surgical instrument for inserting an implantable electrode carrier
includes a housing having a proximal end and a distal end. The
proximal end is configured to hold the implantable electrode
carrier. The instrument also includes a vibration generator
positioned within the housing. The vibration generator is
configured to generate vibrations in at least a portion of the
electrode carrier.
[0009] In related embodiments, the vibration generator may be
positioned within the distal end and/or the proximal end of the
housing. The instrument may further include a power supply coupled
to the vibration generator and positioned within the housing, such
as the distal end of the housing. The power supply is configured to
supply energy to the vibration generator. The vibration generator
may include a floating mass transducer. The floating mass
transducer may include a bushing having an inner area, a permanent
magnet positioned within the inner area of the bushing, and an
electromagnetic coil adjacent to a portion of the bushing. The
electromagnetic coil is configured to move the permanent magnet
within the inner area of the bushing. The floating mass transducer
may further include one or more springs positioned between the
permanent magnet and one end of the bushing so that the spring(s)
are configured to move the permanent magnet back to a neutral
position after the electromagnetic coil moves the permanent magnet
within the inner area of the bushing. The permanent magnet may be
cylindrical or spherical in shape.
[0010] The vibration generator may include an electromotor
connected to a gear, and a mass connected to the gear. The mass is
configured to produce at least a portion of the vibrations
generated by the vibration generator when the gear moves the mass.
Alternatively, or in addition, the vibration generator may include
an electromotor connected to a gear having an unbalanced mass. The
unbalanced mass is configured to produce at least a portion of the
vibrations generated by the vibration generator when the gear moves
the unbalanced mass. The instrument may further include one or more
sensors positioned near the distal end of the housing. The
sensor(s) may be configured to sense a force applied to the
instrument, and the vibration generator may be configured to
control vibrations parameters based on the sensed force. The
vibration generator may impart longitudinal oscillations,
transverse oscillations and/or rotational oscillations to the
proximal end of the housing. The vibration generator may include a
piezoelectric actuator, a pneumatic actuator, an hydraulic
actuator, an electrodynamic actuator and/or a mechanical actuator.
The housing may have a longitudinal axis from the proximal end to
the distal end of the housing, and the vibration generator may be
concentric to the longitudinal axis or offset from the longitudinal
axis.
[0011] In accordance with another embodiment of the invention, a
method of making a surgical instrument for inserting an implantable
electrode carrier includes providing a housing having a proximal
end and a distal end, and providing a vibration generator
positioned within the housing. The proximal end is configured to
hold the implantable electrode carrier, and the vibration generator
is configured to generate vibrations in at least a portion of the
electrode carrier.
[0012] In related embodiments, the method may further include
providing a power supply coupled to the vibration generator and
positioned within the housing. The power supply is configured to
supply energy to the vibration generator. The vibration generator
may include a floating mass transducer that has a bushing having an
inner area, a permanent magnet positioned within the inner area of
the bushing, and an electromagnetic coil adjacent to a portion of
the bushing. The electromagnetic coil is configured to move the
permanent magnet within the inner area of the bushing. The
vibration generator may include an electromotor connected to a gear
having an unbalanced mass, and the unbalanced mass may be
configured to produce at least a portion of the vibrations
generated by the vibration generator when the gear moves the
unbalanced mass. The method may further include providing one or
more sensors positioned near the distal end of the housing. The one
or more sensors are configured to sense a force applied to the
instrument, and the vibration generator is configured to control
vibration parameters based on the sensed force.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing features of the invention will be more readily
understood by reference to the following detailed description,
taken with reference to the accompanying drawings, in which:
[0014] FIG. 1 schematically shows a typical human ear which
includes a cochlear implant system;
[0015] FIG. 2 schematically shows an exemplary surgical instrument
with an integrated vibration generator according to embodiments of
the present invention;
[0016] FIG. 3 schematically shows an electrodynamic vibration
generator that permits axial vibrations according to embodiments of
the present invention;
[0017] FIGS. 4A and 4B schematically show a bushing for an
electrodynamic vibration generator that permits axial and torsional
vibrations according to embodiments of the present invention;
[0018] FIG. 5 schematically shows an electromotor vibration
generator that permits multidimensional vibrations according to
embodiments of the present invention;
[0019] FIG. 6A schematically shows one portion of a gear with an
unbalanced mass that permits multidimensional vibrations according
to embodiments of the present invention;
[0020] FIG. 6B schematically shows a cross-sectional view along
lines B-B of FIG. 6A; and
[0021] FIG. 7 schematically shows a portion of an instrument
holding an implantable electrode carrier according to embodiments
of the present invention.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0022] Various embodiments of the present invention provide a
surgical instrument for inserting an implantable electrode carrier,
methods of making same, and methods of inserting the electrode
carrier, that improves the current implantation process for
electrodes. The surgical instrument includes a housing and a
vibration generator which is integrated into the housing. The
vibration generator is configured to generate vibrations in at
least a portion of the electrode carrier. Details of illustrative
embodiments are discussed below.
[0023] FIG. 1 schematically shows the anatomy of a normal human ear
and some components of a typical cochlear implant system. As shown,
the cochlear implant system includes an external microphone (not
shown) that provides an audio signal input to an external signal
processor 102 where various signal processing schemes may be
implemented. The processed signal is then converted into a
stimulation pattern by an external transmitter/stimulator 104, and
the stimulation pattern/signal is transmitted through connected
wires (not shown) to an implanted electrode carrier 106. The
electrode carrier 106 has an electrode lead 108 and an electrode
array 110. Typically, the electrode array 110 has multiple
electrodes 112 on its surface that provide selective stimulation to
the cochlea 114.
[0024] FIG. 2 schematically shows an illustrative embodiment of a
surgical instrument 120 with an integrated vibration generator that
may be used to implant an electrode carrier. The instrument 120
includes a housing 122 having a proximal end 122a and a distal end
122b. The proximal end 122a is configured to hold the implantable
electrode carrier (not shown in FIG. 2). The instrument 120 also
includes a vibration generator 124 positioned within the housing
122, in the distal end 122b and/or proximal end 122a of the
housing. The vibration generator 124 is configured to generate
vibrations in at least a portion of the electrode carrier. The
housing 122 has a longitudinal axis from the proximal end 122a to
the distal end 122b of the housing, and the vibration generator may
be concentric to the longitudinal axis or offset from this axis.
For example, the vibration generator 124 may be coupled to, or
adjacent to, an inner surface of the housing in one or more
locations so that the vibration generator 124 is relatively equally
spaced from the sides of the housing. Alternatively, the vibration
generator 124 may be coupled to, or adjacent to, one portion of the
inner surface of the housing so that the vibration generator 124 is
closer to one side of the housing than the other. The vibration
generator 124 will be described in more detail below.
[0025] Embodiments of the instrument 120 may also include a power
supply 126 positioned within the housing 122 and coupled to the
vibration generator 124. Preferably, the power supply 126 is
positioned within the distal end of the housing 122. The power
supply 126 supplies energy to the vibration generator 124. The
instrument 120 may include a standard instrument handle 128 at the
distal end of the housing 122 which allows a surgeon to grip the
instrument, guide it and the cochlear implant electrode carrier to
the cochleostomy, and insert the electrode array into the cochlea.
Although one configuration of the instrument 120 is shown, any
standard instrument geometry may be used, e.g., forceps, tweezers,
or surgical claws, that allows an integrated vibration generator
124.
[0026] Embodiments of the instrument 120 may also include one or
more sensors (not shown) positioned on or in the housing 122. The
sensor(s) may be used to detect a force which is applied to the
instrument 120, and the sensed force may be used as an input for
the vibration generator 124. The sensor(s) may be used to give
surgeons the ability to control various vibration parameters
generated by the vibration generator 124 (e.g., an increased
pressure on the handle of the instrument by the surgeon may
increase the amplitude and/or frequency of the vibrations). This
may allow surgeons to implement the instrument and its vibrations
in a much more controlled way. A stopper (not shown) may also be
used with the instrument 120 to prevent overloading of the
electrode carrier caused by any high closing forces of the
instrument 120.
[0027] Embodiments of the vibration generator 124 are configured to
couple vibrations to at least a portion of the electrode carrier.
The frequency and amplitude of the vibrations produced by the
vibration generator 124 are preferably chosen such that the
oscillations produced in the electrode carrier help to overcome the
friction effects and obstacles encountered when inserting the
electrode carrier into the cochlea, reducing possible insertion
trauma. In addition, or alternatively, the vibrations may be
adapted to the vibration characteristics of one or more portions of
the electrode carrier such that any large amplitude deflections of
the electrode carrier may be suppressed or substantially
suppressed. The instrument 120 may have one or more different
vibration modes to provide optimal behaviour of the electrode
carrier inside and outside the cochlea. The vibration parameters
may be optimized to improve the electrode carrier movement, to
improve the stability of the electrode carrier (e.g., to avoid
transversal oscillations of a floppy electrode carrier), and/or to
improve the smoothness of the electrode carrier insertion process.
Vibration parameters may include amplitude, frequency, ascending
and descending slope of the vibration signal and its waveform in
general. Modes of vibrations may include sinusoidal, triangular,
square-wave, saw-tooth-like signals or a combination of two or more
of these modes.
[0028] Various types of systems may be used for the vibration
generator 124. For example, the vibration generator 124 may include
electrodynamic actuators, piezoelectric actuators, pneumatic
actuators, hydraulic actuators, and/or mechanical gear systems,
although other systems may also be used. Preferably, the frequency
of the vibrations may range between 0 to about 100 kHz and the
amplitude of the vibrations may range between 0 to about 5 mm.
Longitudinal, transverse and/or rotational oscillations may be
applied by the vibration generator 124 to the electrode carrier
depending on the configuration of the vibration generator 124.
[0029] For example, FIG. 3 schematically shows an exemplary
floating mass transducer 130 that may be used as a vibration
generator 124 to generate longitudinal or transverse oscillations
within the electrode carrier 106 depending on the orientation of
the transducer 130 in the instrument 120. As shown, the floating
mass transducer 130 includes a bushing 132 having an inner area 134
and a permanent magnet 136 positioned within the inner area 134.
Preferably, the permanent magnet is cylindrical (shown) or
spherical (not shown) in shape. The bushing 132 allows the
permanent magnet 136 to move within the inner area 134 toward
either end 132a, 132b of the bushing 132, and generally along axis,
a, as shown. The floating mass transducer 130 further includes at
least one electromagnetic coil 138 adjacent to a portion of the
bushing 132. As known by those skilled in the art, a current may be
passed through the electromagnetic coil 138, which creates a
magnetic field within the inner area 134 of the bushing 132. In
response to this magnetic field, the permanent magnet 136 moves
within the inner area 134 of the bushing 132 either toward end 132a
or end 132b, depending on the direction of the magnetic field. As
known by those skilled in the art, the direction of the magnetic
field may be changed depending on the direction of the current flow
within the electromagnetic coil 138. The movement of the permanent
magnet 136 within the inner area 134 of the bushing 132 causes
vibrations to be produced by the floating mass transducer 130.
[0030] The floating mass transducer 130 may optionally include one
or more springs or dampers 140 positioned between the permanent
magnet 136 and either end 132a, 132b of the bushing 132. After the
electromagnetic coil 138 has moved the permanent magnet 136 within
the inner area 134, the spring(s) 140 may provide a restoring force
to the permanent magnet 136 and move the permanent magnet 136 back
to a neutral position within the inner area 134. The bushing 132
may be hermetically sealed so as to prevent corrosion and/or
leakage of material into or out of the bushing 132. Preferably, the
bushing 132 is made of a non-ferromagnetic material and may be made
of a biocompatible material, e.g., stainless steel, titanium,
aluminum, platinum, nylon and/or a ceramic material.
[0031] Although FIG. 3 shows a floating mass transducer 130 that
generates axial vibrations, the configuration of the inner area 134
within the bushing 132 may be modified to permit axial and
torsional vibrations according to embodiments of the present
invention. For example, FIG. 4A schematically shows a longitudinal
cross-section of a bushing 142 and its inner area 144, and FIG. 4B
schematically shows a transverse cross-sectional view along line
A-A of FIG. 4A that may be used within a floating mass transducer
to generate both axial and torsional vibrations. As shown, the
permanent magnet 136 may move generally along axis a and axis b
(shown as dashed lines in FIG. 4A) as well as rotate or turn within
the inner area 144. An advantage of adding rotational vibrations to
translational rotation is that rotational vibrations may be
especially effective when trying to overcome obstacles during
electrode carrier insertion.
[0032] Another configuration of a vibration generator 124 that may
be used is a miniaturized electromotor. For example, FIG. 5
schematically shows an electromotor 150 that permits
multidimensional vibrations according to embodiments of the present
invention. As shown, the electromotor 150 may include a motor 152
connected to a gear 154, which in turn is connected to a mass 156
that may move back and forth generally in the direction shown with
arrows. As shown in FIGS. 6A and 6B, the gear 154 may have an
unbalanced mass 158, which when the gear rotates, may generate
multidimensional vibrations. An advantage of a mechanical gear
solution is that the individual parts are generally inexpensive,
simple and reliable.
[0033] An advantage of positioning the vibration generator 124
within the instrument housing 122 is that the entire vibration
unit, including vibration generator 124, power supply 126 and any
electronics, is very compact and may be completely detached from
the instrument housing 122 for sterilization of the housing
122.
[0034] Some embodiments may provide improved methods of inserting
the electrode carrier into the cochlea. For example, as shown in
FIG. 7, the instrument 120 may be configured so that the vibrations
generated impart an axial motion to the housing 122 (as shown by
the double-sided arrow), which may cause the electrode carrier 106
to move forward (as shown by the arrow) with a constant,
incremental movement. This may produce an adjustable feed rate of
the electrode carrier 106 into the cochlea which may result in a
constant, slow and atraumatic insertion process. This automated
insertion method may eliminate the need to have the surgeon
repeatedly grip the electrode carrier 106 with the instrument 120
or apply mechanical force to the electrode carrier 106. This
approach may further reduce the trauma associated with implanting
the electrode carrier into the cochlea since the constant, slow
insertion process may automatically choose the path of lowest
resistance. The instrument 120 may also be configured with a mode
which allows moving the electrode carrier 106 in the reverse
direction, reducing the forces occurring during explantation of
electrode carriers.
[0035] Accordingly, various embodiments of the present invention
improve the electrode insertion process by applying vibrations to
the electrode carrier. Embodiments should not produce any negative
effects on hearing preservation since the motions which are
introduced by the vibrations are negligible in comparison to the
overall electrode insertion trauma.
[0036] Although the above discussion discloses various exemplary
embodiments of the invention, it should be apparent that those
skilled in the art can make various modifications that will achieve
some of the advantages of the invention without departing from the
true scope of the invention.
* * * * *