U.S. patent application number 14/053112 was filed with the patent office on 2014-02-06 for methods for making leads with segmented electrodes for electrical stimulation systems.
This patent application is currently assigned to BOSTON SCIENTIFIC NEUROMODULATION CORPORATION. The applicant listed for this patent is BOSTON SCIENTIFIC NEUROMODULATION CORPORATION. Invention is credited to Andrew DiGiore, Michael Adam Moffitt, Anne Margaret Pianca.
Application Number | 20140039590 14/053112 |
Document ID | / |
Family ID | 45757777 |
Filed Date | 2014-02-06 |
United States Patent
Application |
20140039590 |
Kind Code |
A1 |
Moffitt; Michael Adam ; et
al. |
February 6, 2014 |
METHODS FOR MAKING LEADS WITH SEGMENTED ELECTRODES FOR ELECTRICAL
STIMULATION SYSTEMS
Abstract
One embodiment is a stimulation lead including a lead body
comprising a longitudinal surface, a distal end, and a proximal
end; and multiple electrodes disposed along the longitudinal
surface of the lead body near the distal end of the lead body. The
multiple electrodes include multiple segmented electrodes. At least
a first portion of the lead body, proximal to the electrodes, is
transparent or translucent and at least a second portion of the
lead body, separating two or more of the segmented electrodes, is
opaque so that the segmented electrodes separated by the second
portion of the lead body are visually distinct. Alternatively or
additionally, the stimulation lead can include an indicator ring, a
stripe, a groove, or a marking aligned with one or more of the
segmented electrodes.
Inventors: |
Moffitt; Michael Adam;
(Valencia, CA) ; Pianca; Anne Margaret; (Santa
Monica, CA) ; DiGiore; Andrew; (San Francisco,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOSTON SCIENTIFIC NEUROMODULATION CORPORATION |
Valencia |
CA |
US |
|
|
Assignee: |
BOSTON SCIENTIFIC NEUROMODULATION
CORPORATION
Valencia
CA
|
Family ID: |
45757777 |
Appl. No.: |
14/053112 |
Filed: |
October 14, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13369013 |
Feb 8, 2012 |
8560085 |
|
|
14053112 |
|
|
|
|
61440533 |
Feb 8, 2011 |
|
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|
Current U.S.
Class: |
607/116 |
Current CPC
Class: |
A61N 1/0534 20130101;
A61B 2090/3937 20160201; A61B 2090/3966 20160201; A61N 1/086
20170801; A61N 1/0529 20130101; A61N 1/36182 20130101 |
Class at
Publication: |
607/116 |
International
Class: |
A61N 1/05 20060101
A61N001/05 |
Claims
1. A stimulation lead, comprising: a lead body comprising a
longitudinal surface, a distal end, and a proximal end; a plurality
of electrodes disposed along the longitudinal surface of the lead
body near the distal end of the lead body, the plurality of
electrodes comprising a plurality of segmented electrodes, at least
some of the segmented electrodes formed into a first set of
segmented electrodes comprising at least two of the segmented
electrodes disposed around a circumference of the lead at a first
longitudinal position along the lead, and a second set of segmented
electrodes comprising at least two of the segmented electrodes
disposed around a circumference of the lead at a second
longitudinal position along the lead, wherein the first and second
set of segmented electrodes are adjacent to each other and aligned
with each other; and a marking disposed at or near the distal end
of the lead body and distal to all of the plurality of electrodes,
wherein the marking is aligned with a one of the segmented
electrodes.
2. The stimulation lead of claim 1, wherein the marking comprises
an indicator ring disposed distal to the plurality of electrodes
and marked to indicate alignment of a one of the segmented
electrodes.
3. The stimulation lead of claim 1, wherein the lead comprises a
plurality of the markings disposed at or near the distal end of the
lead body and distal to all of the plurality of electrodes, wherein
each of the markings is aligned with a different one of the
segmented electrodes.
4. The stimulation lead of claim 1, wherein the marking comprises a
colorant.
5. The stimulation lead of claim 1, wherein the marking takes a
form of a symbol.
6. The stimulation lead of claim 5, wherein the symbol is a circle,
triangle, or number.
7. The stimulation lead of claim 1, further comprising a
corresponding marking disposed at or near the proximal end of the
lead body and aligned with the marking disposed at or near the
distal end of the lead body.
8. A stimulation lead, comprising: a lead body comprising a
longitudinal surface, a distal end, and a proximal end; a plurality
of electrodes disposed along the longitudinal surface of the lead
body near the distal end of the lead body, the plurality of
electrodes comprising a plurality of segmented electrodes, at least
some of the segmented electrodes formed into a first set of
segmented electrodes comprising at least two of the segmented
electrodes disposed around a circumference of the lead at a first
longitudinal position along the lead, and a second set of segmented
electrodes comprising at least two of the segmented electrodes
disposed around a circumference of the lead at a second
longitudinal position along the lead, wherein the first and second
sets of segmented electrodes are adjacent to each other and aligned
with each other; and a stripe extending along at least a distal
portion of the lead body and aligned with a one of the segmented
electrodes in each of the first and second sets of segmented
electrodes.
9. The stimulation lead of claim 8, wherein the stripe extends from
a distal end of the lead body.
10. The stimulation lead of claim 9, wherein the stripe extends
from the distal end to a most proximal one of the plurality of
electrodes.
11. The stimulation lead of claim 8, wherein the stripe extends
only between the plurality of electrodes.
12. The stimulation lead of claim 8, wherein the stripe is disposed
proximal to the plurality of electrodes.
13. The stimulation lead of claim 8, wherein the stripe extends to
a proximal end of the lead.
14. The stimulation lead of claim 8, wherein the stripe comprises a
colorant.
15. The stimulation lead of claim 8, wherein the lead comprises a
plurality of the stripes extending along at least a distal portion
of the lead body, wherein each stripe is aligned with a different
one of the segmented electrodes.
16. A stimulation lead, comprising: a lead body comprising a
longitudinal surface, a distal end, and a proximal end; a plurality
of electrodes disposed along the longitudinal surface of the lead
body near the distal end of the lead body, the plurality of
electrodes comprising a plurality of segmented electrodes, at least
some of the segmented electrodes formed into a first set of
segmented electrodes comprising at least two of the segmented
electrodes disposed around a circumference of the lead at a first
longitudinal position along the lead, and a second set of segmented
electrodes comprising at least two of the segmented electrodes
disposed around a circumference of the lead at a second
longitudinal position along the lead, wherein the first and second
sets of segmented electrodes are adjacent to each other and aligned
with each other; and a groove formed in the lead body and extending
along at least a distal portion of the lead body, wherein the
groove is aligned with a one of the segmented electrodes in each of
the first and second sets of segmented electrodes.
17. The stimulation lead of claim 16, wherein the groove extends
from a distal end of the lead body.
18. The stimulation lead of claim 17, wherein the groove extends
from the distal end to a most proximal one of the plurality of
electrodes.
19. The stimulation lead of claim 16, wherein the groove extends to
a proximal end of the lead.
20. The stimulation lead of claim 16, wherein the groove extends
only between the plurality of electrodes.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/369,013 filed Feb. 8, 2012, now U.S. Pat. No.
8,560,085, which claims the benefit under 35 U.S.C. .sctn.119(e) of
U.S. Provisional Patent Application Ser. No. 61/440,533 filed on
Feb. 8, 2011, all of which are incorporated herein by
reference.
FIELD
[0002] The invention is directed to the area of electrical
stimulation systems and methods of making and using the systems.
The present invention is also directed to electrical stimulation
leads with multiple sets of segmented electrodes, as well as
methods of making and using the segmented electrodes, leads, and
electrical stimulation systems.
BACKGROUND
[0003] Electrical stimulation can be useful for treating a variety
of conditions. Deep brain stimulation can be useful for treating,
for example, Parkinson's disease, dystonia, essential tremor,
chronic pain, Huntington's Disease, levodopa-induced dyskinesias
and rigidity, bradykinesia, epilepsy and seizures, eating
disorders, and mood disorders. Typically, a lead with a stimulating
electrode at or near a tip of the lead provides the stimulation to
target neurons in the brain. Magnetic resonance imaging ("MRI") or
computerized tomography ("CT") scans can provide a starting point
for determining where the stimulating electrode should be
positioned to provide the desired stimulus to the target
neurons.
[0004] After the lead is implanted into a patient's brain,
electrical stimulus current can be delivered through selected
electrodes on the lead to stimulate target neurons in the brain.
Typically, the electrodes are formed into rings disposed on a
distal portion of the lead. The stimulus current projects from the
ring electrodes equally in every direction. Because of the ring
shape of these electrodes, the stimulus current cannot be directed
to one or more specific positions around the ring electrode (e.g.,
on one or more sides, or points, around the lead). Consequently,
undirected stimulation may result in unwanted stimulation of
neighboring neural tissue, potentially resulting in undesired side
effects.
BRIEF SUMMARY
[0005] One embodiment is a stimulation lead including a lead body
comprising a longitudinal surface, a distal end, and a proximal
end; and multiple electrodes disposed along the longitudinal
surface of the lead body near the distal end of the lead body. The
multiple electrodes include multiple segmented electrodes.
Optionally, at least some of the segmented electrodes are formed
into a first set of segmented electrodes having at least two of the
segmented electrodes disposed around a circumference of the lead at
a first longitudinal position along the lead, and a second set of
segmented electrodes having at least two of the segmented
electrodes disposed around a circumference of the lead at a second
longitudinal position along the lead. At least a first portion of
the lead body, proximal to the electrodes, is transparent or
translucent and at least a second portion of the lead body,
separating two or more of the segmented electrodes, is opaque so
that the segmented electrodes separated by the second portion of
the lead body are visually distinct.
[0006] Another embodiment is a stimulation lead including a lead
body having a longitudinal surface, a distal end, and a proximal
end; and multiple electrodes disposed along the longitudinal
surface of the lead body near the distal end of the lead body. The
multiple electrodes include multiple segmented electrodes.
Optionally, at least some of the segmented electrodes are formed
into a first set of segmented electrodes having at least two of the
segmented electrodes disposed around a circumference of the lead at
a first longitudinal position along the lead. The stimulation lead
also includes an indicator ring disposed distal to the electrodes
and marked to indicate a one of the segmented electrodes.
[0007] Yet another embodiment is a stimulation lead including a
lead body having a longitudinal surface, a distal end, and a
proximal end; and multiple electrodes disposed along the
longitudinal surface of the lead body near the distal end of the
lead body. The multiple electrodes include multiple segmented
electrodes. At least some of the segmented electrodes are formed
into a first set of segmented electrodes having at least two of the
segmented electrodes disposed around a circumference of the lead at
a first longitudinal position along the lead, and a second set of
segmented electrodes having at least two of the segmented
electrodes disposed around a circumference of the lead at a second
longitudinal position along the lead. The first and second sets of
segmented electrodes are adjacent to each other and aligned with
each other. The stimulation lead also includes a stripe extending
along at least a distal portion of the lead body and aligned with a
one of the segmented electrodes in each of the first and second
sets of segmented electrodes.
[0008] A further embodiment is a stimulation lead including a lead
body comprising a longitudinal surface, a distal end, and a
proximal end; and multiple electrodes disposed along the
longitudinal surface of the lead body near the distal end of the
lead body. The multiple electrodes include multiple segmented
electrodes. At least some of the segmented electrodes are formed
into a first set of segmented electrodes having at least two of the
segmented electrodes disposed around a circumference of the lead at
a first longitudinal position along the lead, and a second set of
segmented electrodes having at least two of the segmented
electrodes disposed around a circumference of the lead at a second
longitudinal position along the lead. The first and second sets of
segmented electrodes are adjacent to each other and aligned with
each other. The stimulation lead also includes a groove formed in
the lead body and extending along at least a distal portion of the
lead body. The groove is aligned with a one of the segmented
electrodes in each of the first and second sets of segmented
electrodes.
[0009] Another embodiment is a stimulation lead including a lead
body comprising a longitudinal surface, a distal end, and a
proximal end; and multiple electrodes disposed along the
longitudinal surface of the lead body near the distal end of the
lead body. The multiple electrodes include multiple segmented
electrodes. At least some of the segmented electrodes are formed
into a first set of segmented electrodes having at least two of the
segmented electrodes disposed around a circumference of the lead at
a first longitudinal position along the lead, and a second set of
segmented electrodes having at least two of the segmented
electrodes disposed around a circumference of the lead at a second
longitudinal position along the lead. The first and second sets of
segmented electrodes are adjacent to each other and aligned with
each other. The stimulation lead also includes a marking disposed
at or near the distal end of the lead body and distal to all of the
electrodes. The marking is aligned with a one of the segmented
electrodes in each of the first and second sets of segmented
electrodes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Non-limiting and non-exhaustive embodiments of the present
invention are described with reference to the following drawings.
In the drawings, like reference numerals refer to like parts
throughout the various figures unless otherwise specified.
[0011] For a better understanding of the present invention,
reference will be made to the following Detailed Description, which
is to be read in association with the accompanying drawings,
wherein:
[0012] FIG. 1 is a schematic side view of one embodiment of a
device for brain stimulation, according to the invention;
[0013] FIG. 2 is a schematic perspective view of one embodiment of
a portion of a lead having a plurality of segmented electrodes,
according to the invention;
[0014] FIG. 3A is a perspective view of a third embodiment of a
portion of a lead having a plurality of segmented electrodes,
according to the invention;
[0015] FIG. 3B is a perspective view of a fourth embodiment of a
portion of a lead having a plurality of segmented electrodes,
according to the invention;
[0016] FIG. 4 is a schematic diagram of radial current steering
along various electrode levels along the length of a lead,
according to the invention;
[0017] FIG. 5 is a perspective view of another embodiment of a
portion of a lead having a plurality of segmented electrodes
arranged in a staggered orientation, according to the
invention;
[0018] FIG. 6A is a perspective view of an embodiment of a portion
of a lead having a plurality of segmented electrodes and opaque
material between the electrodes, according to the invention;
[0019] FIG. 6B is a perspective view of another embodiment of a
portion of a lead having a plurality of segmented electrodes and
opaque material between the electrodes and at a tip of the lead,
according to the invention;
[0020] FIG. 6C is a perspective view of a third embodiment of a
portion of a lead having a plurality of segmented electrodes and
opaque material between the electrodes, at a distal tip of the
lead, and proximal to the electrodes, according to the
invention;
[0021] FIG. 6D is a perspective view of a fourth embodiment of a
portion of a lead having a plurality of segmented electrodes and
opaque material between the sets of segmented electrodes, according
to the invention;
[0022] FIG. 6E is a perspective view of another embodiment of a
portion of a lead having a plurality of segmented electrodes and
opaque material between the segmented electrodes of each set,
according to the invention;
[0023] FIG. 7A is a perspective view of one embodiment of a portion
of a lead having a plurality of segmented electrodes and a marker
at a distal tip of the lead, according to the invention;
[0024] FIG. 7B is a perspective view of another embodiment of a
portion of a lead having a plurality of segmented electrodes and a
marker at a distal tip of the lead, according to the invention;
[0025] FIG. 8A is a perspective view of one embodiment of a portion
of a lead having a plurality of segmented electrodes and a stripe
extending along at least a distal portion of the lead, according to
the invention;
[0026] FIG. 8B is a perspective view of another embodiment of a
portion of a lead having a plurality of segmented electrodes and a
stripe extending along a distal portion of the lead, according to
the invention;
[0027] FIG. 8C is a perspective view of a third embodiment of a
portion of a lead having a plurality of segmented electrodes and a
stripe extending along at least a distal portion of the lead,
according to the invention;
[0028] FIG. 8D is a perspective view of a fourth embodiment of a
portion of a lead having a plurality of segmented electrodes and a
stripe extending along a portion of the lead proximal to the
electrodes, according to the invention;
[0029] FIG. 8E is a perspective view of a fifth embodiment of a
portion of a lead having a plurality of segmented electrodes and a
stripe extending between electrodes at a distal portion of the
lead, according to the invention;
[0030] FIG. 8F is a perspective view of a sixth embodiment of a
portion of a lead having a plurality of segmented electrodes and a
stripe extending along portions of the lead proximal and distal to
the electrodes, according to the invention;
[0031] FIG. 9 is a perspective view of one embodiment of a portion
of a lead having a plurality of segmented electrodes and an
indicator ring on a distal portion of the lead, according to the
invention;
[0032] FIG. 10A is a cross-sectional view of one embodiment of a
portion of a lead body having a groove or notch, according to the
invention; and
[0033] FIG. 10B is a perspective view of another embodiment of a
portion of a lead body having a groove or notch, according to the
invention.
DETAILED DESCRIPTION
[0034] The invention is directed to the area of electrical
stimulation systems and methods of making and using the systems.
The present invention is also directed to forming electrical
stimulation leads with multiple sets of segmented electrodes, as
well as methods of making and using the segmented electrodes,
leads, and electrical stimulation systems.
[0035] A lead for deep brain stimulation may include stimulation
electrodes, recording electrodes, or a combination of both. At
least some of the stimulation electrodes, recording electrodes, or
both are provided in the form of segmented electrodes that extend
only partially around the circumference of the lead. These
segmented electrodes can be provided in sets of electrodes, with
each set having electrodes radially distributed about the lead at a
particular longitudinal position.
[0036] A practitioner may determine the position of the target
neurons using the recording electrode(s) and then position the
stimulation electrode(s) accordingly without removal of a recording
lead and insertion of a stimulation lead. In some embodiments, the
same electrodes can be used for both recording and stimulation. In
some embodiments, separate leads can be used; one with recording
electrodes which identify target neurons, and a second lead with
stimulation electrodes that replaces the first after target neuron
identification. A lead may include recording electrodes spaced
around the circumference of the lead to more precisely determine
the position of the target neurons. In at least some embodiments,
the lead is rotatable so that the stimulation electrodes can be
aligned with the target neurons after the neurons have been located
using the recording electrodes. For illustrative purposes, the
leads are described herein relative to use for deep brain
stimulation, but it will be understood that any of the leads can be
used for applications other than deep brain stimulation.
[0037] Deep brain stimulation devices and leads are described in,
for example, U.S. Pat. No. 7,809,446 ("Devices and Methods For
Brain Stimulation"), U.S. Patent Application Publication No.
2010/0076535 A1 ("Leads With Non-Circular-Shaped Distal Ends For
Brain Stimulation Systems and Methods of Making and Using"), U.S.
Patent Application Publication 2007/0150036 A1 ("Stimulator Leads
and Methods For Lead Fabrication"), U.S. patent application Ser.
No. 12/177,823 ("Lead With Transition and Methods of Manufacture
and Use"), U.S. Patent Application Publication No. 2009/0276021 A1
("Electrodes For Stimulation Leads and Methods of Manufacture and
Use"), U.S. Pat. No. 8,473,061 ("Deep Brain Stimulation Current
Steering with Split Electrodes"), U.S. Patent Application
Publication No. 2009/0187222 A1, and U.S. Patent Application
Publication No. 2012/0165911 A1. Each of these references is
incorporated herein by reference.
[0038] FIG. 1 illustrates one embodiment of a device 100 for brain
stimulation. The device includes a lead 110, a plurality of
electrodes 125 disposed at least partially about a circumference of
the lead 110, a plurality of terminals 135, a connector 130 for
connection of the electrodes to a control unit, and a stylet 140
for assisting in insertion and positioning of the lead in the
patient's brain. The stylet 140 can be made of a rigid material.
Examples of suitable materials for the stylet include, but are not
limited to, tungsten, stainless steel, and plastic. The stylet 140
may have a handle 150 to assist insertion into the lead 110, as
well as rotation of the stylet 140 and lead 110. The connector 130
fits over a proximal end of the lead 110, preferably after removal
of the stylet 140.
[0039] The control unit (not shown) is typically an implantable
pulse generator that can be implanted into a patient's body, for
example, below the patient's clavicle area. The pulse generator can
have eight stimulation channels which may be independently
programmable to control the magnitude of the current stimulus from
each channel. In some cases the pulse generator may have more than
eight stimulation channels (e.g., 16-, 32-, or more stimulation
channels). The control unit may have one, two, three, four, or more
connector ports, for receiving the plurality of terminals 135 at
the proximal end of the lead 110.
[0040] In one example of operation, access to the desired position
in the brain can be accomplished by drilling a hole in the
patient's skull or cranium with a cranial drill (commonly referred
to as a burr), and coagulating and incising the dura mater, or
brain covering. The lead 110 can be inserted into the cranium and
brain tissue with the assistance of the stylet 140. The lead 110
can be guided to the target location within the brain using, for
example, a stereotactic frame and a microdrive motor system. In
some embodiments, the microdrive motor system can be fully or
partially automatic. The microdrive motor system may be configured
to perform one or more the following actions (alone or in
combination): insert the lead 110, retract the lead 110, or rotate
the lead 110.
[0041] In some embodiments, measurement devices coupled to the
muscles or other tissues stimulated by the target neurons, or a
unit responsive to the patient or clinician, can be coupled to the
control unit or microdrive motor system. The measurement device,
user, or clinician can indicate a response by the target muscles or
other tissues to the stimulation or recording electrode(s) to
further identify the target neurons and facilitate positioning of
the stimulation electrode(s). For example, if the target neurons
are directed to a muscle experiencing tremors, a measurement device
can be used to observe the muscle and indicate changes in tremor
frequency or amplitude in response to stimulation of neurons.
Alternatively, the patient or clinician may observe the muscle and
provide feedback.
[0042] The lead 110 for deep brain stimulation can include
stimulation electrodes, recording electrodes, or both. In at least
some embodiments, the lead 110 is rotatable so that the stimulation
electrodes can be aligned with the target neurons after the neurons
have been located using the recording electrodes.
[0043] Stimulation electrodes may be disposed on the circumference
of the lead 110 to stimulate the target neurons. Stimulation
electrodes may be ring-shaped so that current projects from each
electrode equally in every direction from the position of the
electrode along a length of the lead 110. Ring electrodes, however,
typically do not enable stimulus current to be directed to only one
side of the lead. Segmented electrodes, however, can be used to
direct stimulus current to one side, or even a portion of one side,
of the lead. When segmented electrodes are used in conjunction with
an implantable pulse generator that delivers constant current
stimulus, current steering can be achieved to more precisely
deliver the stimulus to a position around an axis of the lead
(i.e., radial positioning around the axis of the lead).
[0044] To achieve current steering, segmented electrodes can be
utilized in addition to, or as an alternative to, ring electrodes.
Though the following description discusses stimulation electrodes,
it will be understood that all configurations of the stimulation
electrodes discussed may be utilized in arranging recording
electrodes as well.
[0045] FIG. 2 illustrates one embodiment of a distal portion of a
lead 200 for brain stimulation. The lead 200 includes a lead body
210, one or more optional ring electrodes 220, and a plurality of
sets of segmented electrodes 230. The lead body 210 can be formed
of a biocompatible, non-conducting material such as, for example, a
polymeric material. Suitable polymeric materials include, but are
not limited to, silicone, polyurethane, polyurea,
polyurethane-urea, polyethylene, or the like. Once implanted in the
body, the lead 200 may be in contact with body tissue for extended
periods of time. In at least some embodiments, the lead 200 has a
cross-sectional diameter of no more than 1.5 mm and may be in the
range of 1 to 1.5 mm. In at least some embodiments, the lead 200
has a length of at least 10 cm and the length of the lead 200 may
be in the range of 25 to 70 cm.
[0046] The electrodes may be made using a metal, alloy, conductive
oxide, or any other suitable conductive biocompatible material.
Examples of suitable materials include, but are not limited to,
platinum, platinum iridium alloy, iridium, titanium, tungsten,
palladium, palladium rhodium, or the like. Preferably, the
electrodes are made of a material that is biocompatible and does
not substantially corrode under expected operating conditions in
the operating environment for the expected duration of use.
[0047] Each of the electrodes can either be used or unused (OFF).
When the electrode is used, the electrode can be used as an anode
or cathode and carry anodic or cathodic current. In some instances,
an electrode might be an anode for a period of time and a cathode
for a period of time.
[0048] Stimulation electrodes in the form of ring electrodes 220
may be disposed on any part of the lead body 210, usually near a
distal end of the lead 200. In FIG. 2, the lead 200 includes two
ring electrodes 220. Any number of ring electrodes 220 may be
disposed along the length of the lead body 210 including, for
example, one, two three, four, five, six, seven, eight, nine, ten,
eleven, twelve, thirteen, fourteen, fifteen, sixteen or more ring
electrodes 220. It will be understood that any number of ring
electrodes may be disposed along the length of the lead body 210.
In some embodiments, the ring electrodes 220 are substantially
cylindrical and wrap around the entire circumference of the lead
body 210. In some embodiments, the outer diameters of the ring
electrodes 220 are substantially equal to the outer diameter of the
lead body 210. The length of the ring electrodes 220 may vary
according to the desired treatment and the location of the target
neurons. In some embodiments the length of the ring electrodes 220
are less than or equal to the diameters of the ring electrodes 220.
In other embodiments, the lengths of the ring electrodes 220 are
greater than the diameters of the ring electrodes 220.
[0049] Deep brain stimulation leads may include one or more sets of
segmented electrodes. Segmented electrodes may provide for superior
current steering than ring electrodes because target structures in
deep brain stimulation are not typically symmetric about the axis
of the distal electrode array. Instead, a target may be located on
one side of a plane running through the axis of the lead. Through
the use of a radially segmented electrode array ("RSEA"), current
steering can be performed not only along a length of the lead but
also around a circumference of the lead. This provides precise
three-dimensional targeting and delivery of the current stimulus to
neural target tissue, while potentially avoiding stimulation of
other tissue.
[0050] In FIG. 2, the lead 200 is shown having a plurality of
segmented electrodes 230. Any number of segmented electrodes 230
may be disposed on the lead body 210 including, for example, one,
two three, four, five, six, seven, eight, nine, ten, eleven,
twelve, thirteen, fourteen, fifteen, sixteen or more segmented
electrodes 230. It will be understood that any number of segmented
electrodes 230 may be disposed along the length of the lead body
210.
[0051] The segmented electrodes 230 may be grouped into sets of
segmented electrodes, where each set is disposed around a
circumference of the lead 200 at a particular longitudinal portion
of the lead 200. The lead 200 may have any number of segmented
electrodes 230 in a given set of segmented electrodes. The lead 200
may have one, two, three, four, five, six, seven, eight, or more
segmented electrodes 230 in a given set. In at least some
embodiments, each set of segmented electrodes 230 of the lead 200
contains the same number of segmented electrodes 230. The segmented
electrodes 230 disposed on the lead 200 may include a different
number of electrodes than at least one other set of segmented
electrodes 230 disposed on the lead 200.
[0052] The segmented electrodes 230 may vary in size and shape. In
some embodiments, the segmented electrodes 230 are all of the same
size, shape, diameter, width or area or any combination thereof. In
some embodiments, the segmented electrodes 230 of each
circumferential set (or even all segmented electrodes disposed on
the lead 200) may be identical in size and shape.
[0053] Each set of segmented electrodes 230 may be disposed around
the circumference of the lead body 210 to form a substantially
cylindrical shape around the lead body 210. The spacing between
individual electrodes of a given set of the segmented electrodes
may be the same, or different from, the spacing between individual
electrodes of another set of segmented electrodes on the lead 200.
In at least some embodiments, equal spaces, gaps or cutouts are
disposed between each segmented electrode 230 around the
circumference of the lead body 210. In other embodiments, the
spaces, gaps or cutouts between the segmented electrodes 230 may
differ in size or shape. In other embodiments, the spaces, gaps, or
cutouts between segmented electrodes 230 may be uniform for a
particular set of the segmented electrodes 230, or for all sets of
the segmented electrodes 230. The sets of segmented electrodes 230
may be positioned in irregular or regular intervals along a length
the lead body 210.
[0054] Conductor wires that attach to the ring electrodes 220 or
segmented electrodes 230 extend along the lead body 210. These
conductor wires may extend through the material of the lead 200 or
along one or more lumens defined by the lead 200, or both. The
conductor wires are presented at a connector (via terminals) for
coupling of the electrodes 220, 230 to a control unit (not
shown).
[0055] When the lead 200 includes both ring electrodes 220 and
segmented electrodes 230, the ring electrodes 220 and the segmented
electrodes 230 may be arranged in any suitable configuration. For
example, when the lead 200 includes two sets of ring electrodes 220
and two sets of segmented electrodes 230, the ring electrodes 220
can flank the two sets of segmented electrodes 230 (see e.g., FIG.
2). Alternately, the two sets of ring electrodes 220 can be
disposed proximal to the two sets of segmented electrodes 230 (see
e.g., FIG. 3A), or the two sets of ring electrodes 220 can be
disposed distal to the two sets of segmented electrodes 230 (see
e.g., FIG. 3B). It will be understood that other configurations are
possible as well (e.g., alternating ring and segmented electrodes,
or the like).
[0056] By varying the location of the segmented electrodes 230,
different coverage of the target neurons may be selected. For
example, the electrode arrangement of FIG. 3A may be useful if the
physician anticipates that the neural target will be closer to a
distal tip of the lead body 210, while the electrode arrangement of
FIG. 3B may be useful if the physician anticipates that the neural
target will be closer to a proximal end of the lead body 210.
[0057] Any combination of ring electrodes 220 and segmented
electrodes 230 may be disposed on the lead 200. For example, the
lead may include a first ring electrode, two sets of segmented
electrodes, each set formed of three segmented electrodes 230, and
a final ring electrode at the end of the lead. This configuration
may simply be referred to as a 1-3-3-1 configuration. It may be
useful to refer to the electrodes with this shorthand notation.
Thus, the embodiment of FIG. 3A may be referred to as a 1-1-3-3
configuration, while the embodiment of FIG. 3B may be referred to
as a 3-3-1-1 configuration. Other eight-electrode configurations
include, for example, a 2-2-2-2 configuration, where four sets of
segmented electrodes are disposed on the lead, and a 4-4
configuration, where two sets of segmented electrodes, each having
four segmented electrodes 230 are disposed on the lead. In some
embodiments, the lead includes 16 electrodes. Possible
configurations for a 16-electrode lead include, but are not limited
to 4-4-4-4; 8-8; 3-3-3-3-3-1 (and all rearrangements of this
configuration); and 2-2-2-2-2-2-2-2.
[0058] FIG. 4 is a schematic diagram to illustrate radial current
steering along various electrode levels along the length of the
lead 200. While conventional lead configurations with ring
electrodes are only able to steer current along the length of the
lead (the z-axis), the segmented electrode configuration is capable
of steering current in the x-axis, y-axis as well as the z-axis.
Thus, the centroid of stimulation may be steered in any direction
in the three-dimensional space surrounding the lead 200. In some
embodiments, the radial distance, r, and the angle .theta. around
the circumference of the lead 200 may be dictated by the percentage
of anodic current (recognizing that stimulation predominantly
occurs near the cathode, although strong anodes may cause
stimulation as well) introduced to each electrode. In at least some
embodiments, the configuration of anodes and cathodes along the
segmented electrodes allows the centroid of stimulation to be
shifted to a variety of different locations along the lead 200.
[0059] As can be appreciated from FIG. 4, the centroid of
stimulation can be shifted at each level along the length of the
lead 200. The use of multiple sets of segmented electrodes at
different levels along the length of the lead allows for
three-dimensional current steering. In some embodiments, the sets
of segmented electrodes are shifted collectively (i.e., the
centroid of simulation is similar at each level along the length of
the lead). In at least some other embodiments, each set of
segmented electrodes is controlled independently. Each set of
segmented electrodes may contain two, three, four, five, six,
seven, eight or more segmented electrodes. It will be understood
that different stimulation profiles may be produced by varying the
number of segmented electrodes at each level. For example, when
each set of segmented electrodes includes only two segmented
electrodes, uniformly distributed gaps (inability to stimulate
selectively) may be formed in the stimulation profile. In some
embodiments, at least three segmented electrodes 230 in a set are
utilized to allow for true 360.degree. selectivity.
[0060] As previously indicated, the foregoing configurations may
also be used while utilizing recording electrodes. In some
embodiments, measurement devices coupled to the muscles or other
tissues stimulated by the target neurons or a unit responsive to
the patient or clinician can be coupled to the control unit or
microdrive motor system. The measurement device, user, or clinician
can indicate a response by the target muscles or other tissues to
the stimulation or recording electrodes to further identify the
target neurons and facilitate positioning of the stimulation
electrodes. For example, if the target neurons are directed to a
muscle experiencing tremors, a measurement device can be used to
observe the muscle and indicate changes in tremor frequency or
amplitude in response to stimulation of neurons. Alternatively, the
patient or clinician may observe the muscle and provide
feedback.
[0061] The reliability and durability of the lead will depend
heavily on the design and method of manufacture. Fabrication
techniques discussed below provide methods that can produce
manufacturable and reliable leads.
[0062] When the lead 200 includes a plurality of sets of segmented
electrodes 230, it may be desirable to form the lead 200 such that
corresponding electrodes of different sets of segmented electrodes
230 are radially aligned with one another along the length of the
lead 200 (see e.g., the segmented electrodes 230 shown in FIG. 2).
Radial alignment between corresponding electrodes of different sets
of segmented electrodes 230 along the length of the lead 200 may
reduce uncertainty as to the location or orientation between
corresponding segmented electrodes of different sets of segmented
electrodes. Accordingly, it may be beneficial to form electrode
arrays such that corresponding electrodes of different sets of
segmented electrodes along the length of the lead 200 are radially
aligned with one another and do not radially shift in relation to
one another during manufacturing of the lead 200.
[0063] FIG. 5 is a side view of another embodiment of the lead 200
having a plurality of sets of segmented electrodes. As shown in
FIG. 5, individual electrodes in the two sets of segmented
electrodes 230 are staggered relative to one another along the
length of the lead body 210. In some cases, the staggered
positioning of corresponding electrodes of different sets of
segmented electrodes along the length of the lead 200 may be
designed for a specific application.
[0064] Typically, the lead body is made of a transparent or
translucent material. It may be difficult to visually distinguish
individual segmented electrodes when the lead body is transparent
or translucent. Visual identification of the segmented electrodes
may be useful so that a practitioner can verify that the lead has
segmented electrodes or to align the segmented electrodes along a
desired orientation for implantation.
[0065] To facilitate visual identification of segmented electrodes,
a portion of the lead body between or around the segmented
electrodes can be opaque, preferably white or a light color. FIG.
6A is a side view of an embodiment of a lead 600 with segmented
electrodes 630 and ring electrodes 620 along the length of a lead
body 610. A portion 640 of the lead body 610 between the electrodes
630, 620 is made of an opaque material so that the segmented
electrodes 630 can be visually identified. The remainder of the
lead body (i.e., the portions not cross-hatched in FIG. 6) can be
transparent or translucent. The opacity of the portion 640 of the
lead body may be limited to the surface of the lead body in portion
640 or may extend partially or completely through portion 640 of
the lead body.
[0066] The opacity of portion 640 of the lead body may be generated
using materials or processing techniques or combinations thereof.
For example, the portion 640 of the lead body may include a
biocompatible colorant or other opaque material, such as, for
example, titanium dioxide, barium sulfate, or white polyethylene.
This colorant or other opaque material may be used in combination
with other materials to form the lead body or may be the sole
material that forms the portion 640 of the lead body. As another
example, the portion 640 of the lead body may be colored by a
processing technique, such as laser marking or scoring, heating,
grinding, or any combination thereof, to generate an opaque
region.
[0067] Region 640 may have any suitable color. Preferably, the
color of region 640 is a light color, such as, for example, white,
off-white, or a pastel color. Preferably, the opaque region is less
visibly reflective than the electrodes 630, 620 and, more
preferably, the opaque region is substantially non-reflective. In
at least some embodiments, roughening the surface of the opaque
region, such as grinding or scoring the surface, may reduce
reflectivity of the opaque region.
[0068] The region 640 of the lead body may have the same durometer
or hardness as other portions of the lead body, or the region 640
may have a higher or lower durometer or hardness compared to other
portions of the lead body.
[0069] The embodiment of FIG. 6A illustrates one example of an
arrangement of an opaque region with respect to segmented
electrodes. In other embodiments, more or less of the lead body may
be opaque. FIG. 6B illustrates another embodiment in which a tip
region 642 is also opaque.
[0070] FIG. 6C illustrates yet another embodiment in which the tip
region 642 and region 644 proximal to the electrodes 630, 620 is
also opaque. FIG. 6D illustrates a further embodiment in which only
the region 646 between the sets of segmented electrodes is opaque.
FIG. 6E is yet another embodiment in which only the region 648
between segmented electrodes of each set is opaque. It will be
understood that the embodiments of FIGS. 6D and 6E can be combined
so that both regions 646 and 648 are opaque. It will be further
understood that the selection of opaque regions illustrated in
FIGS. 6A-6E can also be applied other arrangements of segmented
electrodes and optional ring electrodes.
[0071] Another technique for indicating orientation or position of
the segmented electrodes includes providing a mark at or near the
distal end of the lead, and distal to all of the electrodes, to
indicate the position of at least one of the segmented electrodes.
As an example, FIGS. 7A and 7B illustrate leads 700 with segmented
electrodes 730, optional ring electrodes 720, and a lead body 710.
The lead 700 also includes a marking 702 at the distal tip 704 of
the lead that is aligned with one of the segmented electrodes 730a.
This marking may also align with one of the segmented electrodes in
two sets of segmented electrodes, as illustrated in FIGS. 7A and
7B. It will be recognized that the marking can be aligned, if
desired, with electrodes in more than two sets of segmented
electrodes when the lead contains more than two sets.
[0072] The marking 702 may take any form including a circle (FIG.
7A), line (FIG. 7B), triangle, number, or any other regular or
irregular shape or symbol. The marking may be formed using a
colorant provided during or after formation of the lead body, an
item inserted in the lead body, or by processing techniques such
as, for example, laser scoring or marking, etching, grinding, or
otherwise roughening the surface. A colorant may be provided on the
surface or within the lead body or any combination thereof. The
marking may be any suitable color, preferably, white, off-white, or
some other light color. Optionally, the marking is
radio-opaque.
[0073] In some embodiments, more than one marking is provided at
the distal tip with each marking aligned with a different segmented
electrode or electrodes. In some embodiments, a corresponding
marking or markings may be provided at the proximal end of the lead
and aligned with the marking or markings at the distal end of the
lead.
[0074] Other arrangements for marking the lead body can be used.
FIG. 8A-8F illustrate leads 800 with segmented electrodes 830,
optional ring electrodes 820, and a lead body 810. These leads
include a stripe 850 that extends along portions of the lead body
near a distal end of the lead. The stripe is aligned with at least
one segmented electrode and may be aligned with a segmented
electrode in two or more sets of segmented electrodes as
illustrated in FIGS. 8A-8F. Optionally, the stripe may extend to a
proximal portion of the lead and may even extend to, or near, a
proximal end of the lead.
[0075] In FIG. 8A, the stripe 850 extends along the lead body 810
from a distal tip to a location proximal of the electrodes 820, 830
of the lead 800. In FIG. 8B, the stripe 850 extends from the distal
tip to the most proximal electrode 820a. In FIG. 8C, the stripe 850
extends from the most distal electrode 820b to a location proximal
to the electrodes 820, 830. In FIG. 8D, the stripe 850 extends
proximally from the most proximal electrode 820a. In FIG. 8E, the
stripe 850 extends from the most distal electrode 820b to the most
proximal electrode 820a. In FIG. 8F, the strip 850 extends distally
from the most distal electrode 820b and proximally from the most
proximal electrode 820a, but not between the electrodes.
[0076] The stripe may be formed using a colorant or by processing
techniques such as, for example, laser scoring or marking, etching,
grinding, or otherwise roughening the surface. A colorant may be
provided on the surface or within the lead body or any combination
thereof. The stripe may be any suitable color, preferably, white,
off-white, or some other light color. Optionally, the strip is
radio-opaque.
[0077] In some embodiments, more than one stripe may be used. In
such embodiments, the different stripes may have different colors
and are associated with different segmented electrodes. For
example, a lead may have a stripe of a first color associated with
the first segmented electrode in one or more (or even all) sets of
segmented electrodes and another stripe of a second color
associated with the second segmented electrode in one or more (or
even all) sets of segmented electrodes. Additional stripes could be
used for the third, fourth, or fifth electrodes and so on.
[0078] Alternatively, instead of a stripe, a groove or notch may be
used and positioned at the same locations as stripe 850 in any of
FIGS. 8A-8F. FIGS. 10A and 10B are schematic cross-sectional
illustrations of embodiments of a lead body 1010 with a groove or
notch 1070 formed in the exterior surface of the lead body. The
groove or notch may be formed during or after generation of the
lead body. The groove or notch may have any cross-sectional shape
including, but not limited, circular (e.g., FIG. 10A), square
(e.g., FIG. 10B), triangular, and the like. Optionally, the groove
or notch may be colored.
[0079] FIG. 9 illustrates a lead 900 with segmented electrode 930,
optional ring electrodes 920, a lead body 910, and an indicator
ring 960. The indicator ring 960 is marked to indicate a particular
segmented electrode or particular segmented electrodes in two or
more sets of segmented electrodes. The indicator ring 960 may be
marked in any suitable manner including, but not limited to,
scoring, etching, engraving, removing a portion of the ring, and
the like. The indicator ring 960 may be made of any suitable
biocompatible material including metals, polymers, and ceramics.
The indicator ring may be radio-opaque.
[0080] The above specification, examples, and data provide a
description of the manufacture and use of the composition of the
invention. Since many embodiments of the invention can be made
without departing from the spirit and scope of the invention, the
invention also resides in the claims hereinafter appended.
* * * * *