U.S. patent application number 10/997045 was filed with the patent office on 2005-07-21 for percutaneous-insertion needle and method of implanting a lead.
This patent application is currently assigned to ADVANCED NEUROMODULATION SYSTEMS, INC.. Invention is credited to Daglow, Terry, Hooper, Sandy.
Application Number | 20050159799 10/997045 |
Document ID | / |
Family ID | 34652287 |
Filed Date | 2005-07-21 |
United States Patent
Application |
20050159799 |
Kind Code |
A1 |
Daglow, Terry ; et
al. |
July 21, 2005 |
Percutaneous-insertion needle and method of implanting a lead
Abstract
An improved needle for use in percutaneous insertion of a lead,
and method for insertion of same, is provided. The needle includes
a flare or lip on the needle heel proximate the needle orifice.
Inventors: |
Daglow, Terry; (Allen,
TX) ; Hooper, Sandy; (Allen, TX) |
Correspondence
Address: |
BAKER BOTTS L.L.P.
2001 ROSS AVENUE, 6TH FLOOR
DALLAS
TX
75201-2980
US
|
Assignee: |
ADVANCED NEUROMODULATION SYSTEMS,
INC.
Plano
TX
75024
|
Family ID: |
34652287 |
Appl. No.: |
10/997045 |
Filed: |
November 24, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60524982 |
Nov 25, 2003 |
|
|
|
Current U.S.
Class: |
607/116 |
Current CPC
Class: |
A61N 1/0529 20130101;
A61N 1/0551 20130101 |
Class at
Publication: |
607/116 |
International
Class: |
A61N 001/05 |
Claims
What is claimed is:
1. A needle for percutaneous insertion of a device, the needle
comprising: a body having a proximal end and a distal end; and an
introducer portion at the distal end and having an orifice, the
introducer portion including a flared portion proximate a heel of
the body.
2. The needle in accordance with claim 1 wherein the flared portion
has a first radius of curvature and the introducer portion has a
second radius of curvature, and the first radius of curvature is
less than the second radius of curvature of the introducer
portion.
3. The needle in accordance with claim 1 wherein an inner diameter
at the flared portion is greater than an inner diameter at an
adjacent body portion.
4. A percutaneous insertion needle comprising: an elongated body
having a passage extending from a proximal end portion to a distal
end portion of the needle; an introducer portion at the distal end
portion and adjacent a body portion of the body, the introducer
having an orifice and a heel portion, the heel portion including a
lip portion; and wherein a cross section area of the lip portion is
greater than a cross section area of the adjacent body portion.
5. The needle in accordance with claim 4 wherein the flared portion
has a first radius of curvature and the introducer portion has a
second radius of curvature, and the first radius of curvature is
less than the radius of curvature of the introducer portion.
6. The needle in accordance with claim 4 wherein an inner diameter
at the flared portion is greater than an inner diameter at an
adjacent body portion.
7. A method of placing a lead in a body, the method comprising:
providing a needle, comprising, a body having a proximal end and a
distal end, and an introducer portion at the distal end and having
an orifice, the introducer portion including a flared portion
proximate a heel of the body; percutaneously accessing a site
within the body proximate to a desire lead placement location in
the body using the needle; and directing the lead through the
needle into the site.
8. The method in accordance with claim 7 wherein the flared portion
of the needle has a first radius of curvature and the introducer
portion has a second radius of curvature, and the first radius of
curvature is less than the radius of curvature of the introducer
portion.
9. The method in accordance with claim 7 wherein an inner diameter
at the flared portion of the needle is greater than an inner
diameter at an adjacent body portion.
10. A system for treating neurological disorders, the system
comprising: a source for generating a stimulus; an implantable lead
operable for receiving the stimulus from the source; and a needle
for percutaneous insertion of the lead, the needle comprising: a
body having a proximal end and a distal end, and an introducer
portion at the distal end and having an orifice, the introducer
portion including a flared portion proximate a heel of the
body.
11. The system in accordance with claim 10 wherein the flared
portion has a first radius of curvature and the introducer portion
has a second radius of curvature, and the first radius of curvature
is less than the radius of curvature of the introducer portion.
12. The system in accordance with claim 10 wherein an inner
diameter at the flared portion is greater than an inner diameter at
an adjacent body portion.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit and priority (under 35
U.S.C. .sctn.119(e)) to prior U.S. provisional application Ser. No.
60/524,982 filed on Nov. 25, 2003, and which is incorporated herein
by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to electrical leads,
percutaneous needles and methods of implanting such leads.
BACKGROUND
[0003] Implantable leads having electrodes are used in a variety of
applications, including the delivery of electrical stimulation to
surrounding tissue, neural or otherwise, as well as measuring
electrical energy produced by such tissue. Some leads include
lumens for the delivery of other elements, including chemicals and
drugs. Whether in a stimulation, sensing or element delivery
capacity, such leads are commonly implanted along peripheral
nerves, within the epidural or intrathecal space of the spinal
column, and around the heart, brain, or other organs or tissue of a
patient.
[0004] Differing techniques have been utilized to construct or
manufacture such leads. Some prior art leads and methods of
manufacture have been disclosed in several United States patents,
such as U.S. Pat. Nos. 5,016,646 (Gotthardt, et al.), 5,433,742
(Willis), 6,208,881 (Champeau) and 6,216,045 (Black, et al.), which
are each incorporated herein by reference. One example of a
directional brain stimulation and recording leads is disclosed in
PCT publication WO 02/045795 (Jun. 13, 2002), which is incorporated
herein by reference. A length of tubing having a window cut therein
forms a sleeve insulating member (or formed by injection molding,
vulcanization molding) that is placed over the distal end of the
lead.
[0005] Generally, several elements (conductors, electrodes and
insulation) are combined to produce a lead body. A lead typically
includes one or more conductors extending the length of the lead
body from a distal end to a proximal end of the lead. The
conductors electrically connect one or more electrodes at the
distal end to one or more connectors at the proximal end of the
lead. The electrodes are designed to form an electrical connection
or stimulus point with tissue or organs. Lead connectors (sometimes
referred to as contacts, or contact electrodes) are adapted to
electrically and mechanically connect leads to implantable pulse
generators or RF receivers (stimulation sources), or other medical
devices. An insulating material typically forms the lead body and
surrounds the conductors for electrical isolation between the
conductors and protection from the external contact and
compatibility with a body.
[0006] Such leads are typically implanted into a body at an
insertion site and extend from the implant site to the stimulation
site (area of placement of the electrodes). The implant site is
typically a subcutaneous pocket that receives and houses the pulse
generator or receiver (providing a stimulation source). The implant
site is usually positioned a distance away from the stimulation
site, such as near the buttocks or other place in the torso area.
In some cases, the implant site (and/or insertion site) is located
in the lower back area, and the lead may extend through the
epidural space (or other space) in the spine to the stimulation
site (middle or upper back, or neck or brain areas). In other
cases, the implant site may be located in the brain or other part
of the body. In still other cases, the stimulation source may not
be implanted, and may be external to the body.
[0007] Application of specific electrical fields to spinal nerve
roots, spinal cord, deep brain stimulation, and other nerve bundles
or tissue for the purpose of pain control has been actively
practiced for years. While a precise understanding of the
interaction between the applied electrical energy and the
stimulated tissue is not fully appreciated, it is known that
application of an electrical field to spinal or other tissue (e.g.,
spinal nerve roots and spinal cord bundles) can effectively mask
certain types of pain transmitted from regions of the body
associated with the stimulated tissue.
[0008] It is known that each exterior region, or each dermatome, of
the human body is associated with a particular spinal nerve root at
a particular longitudinal spinal position. The head and neck
regions are associated with C2-C8, the back regions with C2-S3, the
central diaphragm is associated with spinal nerve roots between C3
and C5, the upper extremities correspond to C5 and T1, the thoracic
wall extends from T1 to T11, the peripheral diaphragm is between T6
and T11, the abdominal wall is associated with T6-L1, the lower
extremities related to L2 to S2, and the perineum from L4 to S4. By
example, to address pain sensations that commonly focus on the
lower back and lower extremities, a specific energy field can
usually be applied to a region between bony level T8 to T10. As
should be understood, successful therapy management and the
avoidance of stimulation in unafflicted regions generally requires
the applied electric field to be properly positioned longitudinally
along the dorsal column.
[0009] Therapy-managing electrical energy is commonly delivered
through electrodes positioned at the desired stimulation site. The
electrodes are generally carried by one of two types of leads:
percutaneous and laminotomy (commonly referred to as "paddle"
leads).
[0010] Percutaneous leads (including catheter types) are generally
small in diameter and have a plurality of spaced electrodes.
Percutaneous leads are typically placed within the body through the
use of a Touhy-like needle. For insertion, the Touhy-like needle is
passed through the skin at the desired location (insertion site)
and the lead is inserted through the needle.
[0011] Laminotomy leads have a paddle configuration, and are
generally larger than percutaneous leads, and typically possess a
plurality of electrodes (for example, two, four, eight, or sixteen)
arranged in one or more columns.
[0012] Laminotomy leads are generally used for applications in
which is it desirous that the applied electrical energy
(stimulation) be directional in nature, such as to address both
unilateral and bilateral pain, where electrical energy may be
administered using either column independently (on either side of
the midline) or administered using both columns to create an
electric field which traverses the midline. A multi-column
laminotomy lead may enable reliable positioning of a plurality of
electrodes, and in particular, provide a plurality of electrode
columns that do not readily deviate from an initial implantation
position/orientation.
[0013] However, laminotomy leads require a significant surgical
procedure for implantation. The surgical procedure generally
requires the resection and removal of certain tissue (vertebral
tissue in the case of spinal applications) to allow both access to
the dura and proper positioning of a laminotomy lead.
[0014] Percutaneous leads, in contrast, require a less-invasive
implantation method, and with a plurality of electrodes, provide a
user the ability to create almost any electrode array. However,
prior art percutaneous leads generally have band-type electrodes
whereby the electrical energy field radiates circumferentially and
therefore the electrical energy may not be focused solely on the
desired area. Although likely more stable during use and
directional in nature, laminotomy leads require a more complicated
surgical procedure for implantation and removal.
[0015] Notwithstanding the range of electric fields that are
possible with conventional stimulation leads, in certain instances
it is necessary to concentrate electrical energy at a particular
point, or over a small region. As an example of such occasion,
assume therapy-managing electrical energy is applied at or about T8
to address only localized lower back pain. At T8, spinal nervous
tissue corresponding to the patient's lower extremities may also
commingle with the specific spinal nervous tissue associated with
the lower back. Since it is common that the lower back-related
spinal nervous tissue is deeply embedded within the combined spinal
nervous tissue, it becomes desirable to focus applied electrical
energy to the targeted nervous tissue to (i) reach the deeply
situated target nervous tissue and (ii) avoid undesirable
stimulation of unafflicted regions, while avoiding surgical
procedures for the lead(s) implantation and removal.
[0016] Accordingly, a need exists for a stimulation lead that
includes a structural arrangement that facilitates directional
concentration of delivered electrical energy at a point, i.e., for
a given electrode, or over a small region, i.e., for a plurality of
electrodes, and at the same time, may be implanted (and/or removed)
without significant surgical procedure.
[0017] Additionally, implantation of leads using percutaneous
methods involves the insertion of the lead into the body via a
needle used as a passageway into the body. During the insertion
procedure, the lead is pushed (forward) into the body, and in some
occasions, there is a need for the lead to be pulled back (partly
or completely) through the needle. This problem is described
further by reference to FIG. 10. FIG. 10 illustrates the lead or
catheter being inserted through the needle, and the potential
problem when the lead is pulled back through the needle, likely due
to repositioning by the clinician. When this occurs with prior art
needles, there is a likelihood that the needle will cut or damage
the lead, as shown.
[0018] Accordingly, there exists a need for a needle for use in
percutaneous insertions which reduces the likelihood that, when an
inserted lead is pulled back through the needle, the lead could be
damaged.
SUMMARY
[0019] In accordance with the present invention, there is provided
a needle for percutaneous insertion of a device. The needle
includes a body having a proximal end and a distal end, and an
introducer portion at the distal end and having an orifice, the
introducer portion including a flared portion proximate a heel of
the body.
[0020] In another embodiment of the present invention, there is
provided a percutaneous insertion needle including an elongated
body having a passage extending from a proximal end portion to a
distal end portion of the needle, and an introducer portion at the
distal end portion and adjacent a body portion of the body, the
introducer having an orifice and a heel portion, the heel portion
including a lip portion, and wherein the cross section area of the
lip portion is greater than a cross section area of the adjacent
body portion.
[0021] In yet another embodiment of the present invention, there is
provided a method of placing a lead in a body. The method includes
providing a needle including a body having a proximal end and a
distal end, and an introducer portion at the distal end and having
an orifice, the introducer portion including a flared portion
proximate a heel of the body. The method further includes
percutaneously accessing a site within the body proximate to a
desire lead placement location in the body using the needle and
directing the lead through the needle into the site.
[0022] In still another embodiment of the invention, there is
provided a system for treating neurological disorders. The system
includes a source for generating a stimulus and an implantable lead
for receiving the stimulus from the source. A needle for
percutaneous insertion of the lead includes a body having a
proximal end and a distal end, and an introducer portion at the
distal end and having an orifice, the introducer portion including
a flared portion proximate a heel of the body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] For a more complete understanding of the present invention,
and the advantages thereof, reference is now made to the following
descriptions taken in conjunction with the accompanying drawings,
wherein like numbers designate like objects, and in which:
[0024] FIG. 1 is perspective view of a lead in accordance with the
present invention;
[0025] FIG. 2A is a more detailed perspective view of one
embodiment of the distal end of the lead shown in FIG. 1;
[0026] FIG. 2B is a more detailed perspective view of another
embodiment of the distal end of the lead shown in FIG. 1;
[0027] FIG. 3A illustrates one embodiment of a process of making
the lead shown in FIG. 2A;
[0028] FIG. 3B illustrates one embodiment of a process of making
the lead shown in FIG. 2B;
[0029] FIG. 4 illustrates one embodiment of a system for
stimulation in accordance with the present invention;
[0030] FIG. 5 illustrates another embodiment of a system for
stimulation in accordance with the present invention;
[0031] FIG. 6A shows the lead of FIG. 2A with one embodiment of the
marking or orientation system;
[0032] FIG. 6B is an enlarged perspective view of the marker shown
in FIG. 6A.
[0033] FIG. 7 illustrates a typical prior art percutaneous
insertion needle;
[0034] FIG. 8 illustrates a percutaneous insertion needle in
accordance with the present invention;
[0035] FIG. 9A is a partial side view showing the tip of the needle
of FIG. 8;
[0036] FIG. 9B is a partial top view showing the tip of the needle
of FIG. 8;
[0037] FIG. 10 illustrates a typical prior art needle and a problem
associated therewith; and
[0038] FIG. 11 illustrates the needle of the present invention
showing a lead being pulled back through the needle and not being
damaged.
DETAILED DESCRIPTION OF THE INVENTION
[0039] With reference to FIG. 1, there is illustrated an embodiment
of a lead 10 in accordance with the present invention. The lead 10
includes a distal end 14 and a proximal end 16. The lead 10
includes a lead body 12 that extends from the distal end 14 to the
proximal end 16. The distal end 14 of the lead 10 is shown
including four electrodes 18. The proximal end 16 of the lead 10 is
shown including four contact electrodes (or ring electrodes) 20
that form a lead connector. The lead 10 generally includes one or
more conductors 26 (not shown) extending a substantial portion of
the lead 10 to electrically connect the contact electrodes 20 to
respective electrodes 18. An optional lumen 24 is shown that
extends through the lead 10 and may be used for different purposes,
including the delivery of chemicals or drugs.
[0040] As will be appreciated, any number of conductors 26,
electrodes 18 and contact electrodes 20 may be utilized, as
desired. For purposes of illustration only, the lead 10 is shown
with four contact electrodes 20 and four electrodes 18. It will be
further understood that the distal end 14 of the lead 10 is shown
with electrodes 18 as described further below. In addition, other
types, configurations and shapes of contact electrodes 20 (and lead
connectors) as known to those skilled in the art may be used, as
desired.
[0041] Typically, the lead body 12 is a structure having a round
cross-section. Alternatively, the cross-section of the lead body 12
may be configured in any number of cross-sectional shapes
appropriate for the specific application. The figures and following
description generally refer to a round cross-sectional shape for
the lead body 12 for illustrative purposes only. The lead body 12
generally includes a lead body insulator 22 configured to insulate
the conductors 26 and presents a biocompatible external surface to
the body tissue. In one embodiment, the lead body insulator 22 is
coextensive with the conductors 26.
[0042] The lead body insulator 22 is formed of insulating material
typically selected based upon biocompatibility, biostability and
durability for the particular application. The insulator material
may be silicone, polyurethane, polyethylene, polyamide,
polyvinylchloride, PTFT, EFTE, or other suitable materials known to
those skilled in the art. Alloys or blends of these materials may
also be formulated to control the relative flexibility,
torqueability, and pushability of the lead 10. Depending on the
particular application, the diameter of the lead body 12 may be any
size, though a smaller size is more desirable for neurological and
myocardial mapping/ablation leads and neuromodulation and
stimulation leads.
[0043] The conductors (not shown) may take the form of solid wires,
drawn-filled-tube (DFT), drawn-brazed-strand (DBS), stranded wires
or cables, ribbons conductors, or other forms known or recognized
to those skilled in the art. The composition of the conductors may
include aluminum, stainless steel, MP35N, platinum, gold, silver,
copper, vanadium, alloys, or other conductive materials or metals
known to those of ordinary skill in the art. The number, size, and
composition of the conductors will depend on the particular
application for the lead 10, as well as the number of
electrodes.
[0044] The conductors may be configured along the lead body 12 in a
straight orientation or spirally or helically wound about the lumen
24 or center of the lead body 12. The conductors are typically
insulated from the lumen 24, from each other, and from the external
surface of the lead 10 by the insulative material 22. The
insulative material 22 may be of a single composition, or multiple
layers of the same or different materials.
[0045] At least one electrode 18 is positioned at the distal end 14
of the lead body 12 for electrically engaging a target tissue or
organ. In addition, at least one connector 20 is positioned at the
proximal end 16 of the lead body 12 for electrically connecting the
conductors 26 to a stimulating or receiving source. In one
embodiment, the lead 10 is generally configured to transmit an
electric signal from an electrical source (see FIGS. 4 and 5) for
application at, or proximate to, a spinal nerve or peripheral
nerve, or other tissue.
[0046] The electrodes 18 and contact electrodes 20 are typically
made of a conductive material such as platinum, gold, silver,
platinum-iridium, stainless steel, MS35N, or other conductive
materials, metals or alloys known to those skilled in the art. The
size of the electrodes 18 is generally chosen based upon the
desired application. The contact electrodes 20 generally have a
size and configuration appropriate to connect the lead 10 to a
desired electrical source or receiver.
[0047] With reference to FIGS. 2A and 2B, there are illustrated
detailed perspective views of distal ends 14a, 14b of the lead 10
of the present invention. In FIG. 2A, the distal end 14a the lead
body 12a is shown with an insulative member 50a (or insulating
material) extending over the electrodes 18a. Openings 52a (i.e.,
windows, apertures) extending through the insulative member 50a are
formed to expose at least a portion of the electrodes 18a. As will
be appreciated, the dotted line identified by reference numeral 58
assists in illustrating the location of the lead body 12a in
relation to the insulative member 50a. Methods of construction of
the lead 10 having a distal end 14a, as shown in FIG. 2A, will be
described in further detail below.
[0048] In FIG. 2B, the distal end 14b of the lead body 12b is shown
with an insulative member 50b (or insulating material) extending
over the electrodes 18b. Openings 52b (i.e., windows, aperatures)
extending through the insulative member 50b are formed to expose at
least a portion of the electrodes 18b. As will be appreciated, the
dotted line identified by reference numeral 60 assists in
illustrating the location of the lead body 12b in relation to the
insulative member 50a. The construction of the lead 10 having a
distal end 14b, as shown in FIG. 2B, will be described in further
detail below.
[0049] With respect to both embodiments shown in FIGS. 2A AND 2B,
in one embodiment, the electrodes 18 are spaced apart and extend
only substantially circumferentially around the lead body 12 (not
shown) or only extend around a predetermined distance as desired
(i.e. such as from about 45 degrees to about 180 degrees, or
one-eighth to one-half the circumference). In another embodiment,
the electrodes 18 extend completely around the lead body 12, as
shown in FIGS. 2A and 2B, and are typically referred to as band
electrodes. In addition, in one embodiment (as shown), each of the
electrodes has a corresponding opening 52 through the insulative
member 50. In another embodiment (not shown), the exposed portions
of the electrodes 18 are exposed through the use of a single
opening 52 in the insulative member 50, or any number of openings
could be used each exposing one or multiple electrodes.
[0050] The location and shape of the openings 52 in the insulating
member 50 mask a portion of the electrodes 18 and function to limit
the electrical energy that is transmitted from each of the
electrodes 18 when activated (stimulus) and/or to direct the energy
in a desired direction. The energy from the electrodes 18 (or
electrode array) can be focused in a limited direction less than
the typical 360 degrees associated with band electrodes (a length
along the circumference and longitudinal length may be desired, and
in one embodiment, about 10 to 180 degrees of the circumference is
possible, with about 45 or 90 degrees preferred).
[0051] As illustrated in FIGS. 2A and 2B, the openings 52 are
substantially aligned parallel to the longitudinal axis of the lead
body, and similar in size and shape, and thus produce a lead that
is unidirectional. Other alignments, sizes and shapes of the
openings may be used, for the specific application(s) as desired so
that the lead has more than one "direction" of stimulation; the
direction of stimulation depending on which electrode is used and
the alignment of that electrode's opening. As will be appreciated,
in another embodiment, an opening 52 may expose more than one of
the electrodes 18.
[0052] As is known in the art, following implantation in the spinal
area, tissue will grow around the electrode (paddle or percutaneous
lead) and will usually increase the impedance associated with the
electrode, thus reducing its ability to electrically couple with
the targeted tissue. In order to maintain a constant or adequate
degree of stimulation, it may be necessary to increase the energy
delivered as the impedance increases. This creates the risk of
stimulating or over-stimulating areas that are not intended to be
stimulated. One typical solution to this problem has been to use a
paddle lead, however, a paddle lead is large and is not
percutaneously implanted, therefore requires significant surgical
procedure and is guided to the target area. Additionally it is not
appropriate in certain applications, such as for brain stimulation
leads.
[0053] The directional or unidirectional lead 10 provided by the
present invention is a percutaneous lead that directs the energy
array of the electrode in a specified or desired direction. With
this ability, a clinician can target a small area of nerves for
stimulation without the danger of over-stimulation of non-targeted
nerves or other nearby tissues.
[0054] The present invention provides a percutaneous lead capable
of directionally sending energy from the lead. The directional
capability of this lead is derived from the fact that part of the
electrode(s) associated with the lead is masked by insulative
material. Stimulation energy from the electrode array can be
focused in a desired (and/or limited) direction (or specific area
or point) that is less than 360 degrees (as measured
circumferentially). The present invention lead has the same uses as
traditional paddle leads, but may be smaller in size and shape. The
directional lead is typically the same size and shape as a
traditional percutaneous lead. With this in mind, it is possible to
implant the lead using the same techniques used to implant
traditional percutaneous leads via needle. Thus, the present
invention lead provides a percutaneous lead having selective
directional stimulation. As will be appreciated, use of two or more
leads having a directional nature allow the electric fields to be
directed between the two leads to more effectively stimulate the
targeted tissue while avoiding excess stimulation of other
structures.
[0055] With regards to the embodiments shown in FIGS. 2A and 2B,
the insulative members 50a, 50b may be formed from a variety of
materials including biocompatible plastics and other suitable
insulative materials, such as polyurethane, pellethane, or the
like. In one embodiment, the insulative members 50a, 50b are a
separate and sleeve-like member that is placed over the distal end
of the lead. The windows 52a, 52b may be formed, cut or machined
within a length of tubing to form the insulating members 50a, 50b.
Also, the insulating members 50a, 50b may be formed by any suitable
molding technique, such as injection molding or the like. After the
insulative members 50a, 50b are prepared or provided, the member is
placed/applied/fixed (not shown, and by various methods known to
those skilled in the art) over the distal end to cover a portion of
the electrode(s) and expose a portion of the electrode(s).
[0056] With reference to FIGS. 3A and 3B, there are shown
embodiments of additional processes or methods for manufacturing
the lead 10 of the present invention. With reference to FIG. 3A, at
a step 300, a typical lead body is provided. The lead body 12a may
be a lead body constructed according to methods and processes
generally available or known to those skilled in the art, such as
those described in U.S. Pat. No. 6,216,045, which is incorporated
herein by reference. At a step 302, the insulating member or
insulating layer 50a is formed over the electrodes 18a (see FIG.
2A). At a step 304, the openings 52a (apertures or windows) are
formed to expose at least a portion of the electrodes 18a. In the
embodiment shown, the insulating member 50a is formed over the
distal end 14 of the lead 10. Alternatively, the insulating member
50a may be formed over a substantial length of the lead 10, and may
extend from the distal end 14 to a point at or near the proximal
end 16. In one embodiment, the insulative member 50a and windows
52a are formed as described previously.
[0057] With reference to FIG. 3B, at a step 330, a typical lead
body is provided prior to affixation or placement of the electrodes
18b. The lead body 12b may be a lead body constructed according to
methods and processes generally available or known to those skilled
in the art, such as those described in U.S. Pat. No. 6,216,045. At
a step 332, a layer of the existing lead body insulator 22 is
removed along the distal end 14 (see dotted line identified by
reference numeral 60 in FIG. 2B illustrating the removal of the
existing layer). This may be accomplished by etching, grinding, or
other techniques known to those skilled in the art. At a step 334,
the electrodes 18b are attached (and electrically connected to the
conductors, not shown) in known fashion.
[0058] At a step 336, the insulating member or insulating layer 50b
is formed over the electrodes 18b (see FIG. 2B). At a step 338, the
openings 52b (apertures or windows) are formed to expose at least a
portion of the electrodes 18b. In the embodiment shown, the
insulating member 50b is formed over the distal end 14 of the lead
10 (alternatively, the insulating member 50b may be formed over a
substantial length of the lead 10, and may extend from the distal
end 14 to a point at or near the proximal end 16). In one
embodiment, the insulative member 50b and windows 52b are formed as
described previously.
[0059] Alternatively, the lead of step 330 may include the
electrodes, and the removing step 332 may further include removing
a layer of the insulative material and a similar outer layer of the
electrode(s). In this embodiment, the step 334 would be
omitted.
[0060] In one embodiment, the insulating member or layer 50a, 50b
is made of any suitable insulative material sufficient to
substantially prevent or substantially reduce electrical radiation
from the electrodes 18a, 18b. In another embodiment, the insulating
member or layer 50a, 50b is composed of paralyne. Thicknesses of
the insulating member or layer 50a, 50b can range from 0.0005 to
0.002 inches, and is preferable in the range of 0.0005 to 0.0009
inches, and may be about 0.0007 inches. The insulative member or
layer 50a, 50b may be formed in the forming step 302, 336 by
various methods, including chemical or physical vapor deposition,
sputtering, thermal growth, etc.
[0061] In one embodiment, the insulating member or layer 50a, 50b
is formed over the entire portion of each electrode 18a, 18b and,
subsequently, a selected portion (the portion desired to be
exposed) of the insulating member 50a, 50b is removed to form the
openings 52a, 52b. Different techniques may be utilized to form the
openings 52a, 52b, including laser ablation, etching, cutting, or
similar and like methods sufficient to remove a selected portion
and expose the electrode 18a, 18b. In another embodiment, masking
material (or a masking layer) (not shown) is used to selectively
mask the portion of the electrode 18a, 18b desired to be exposed.
The insulating member/layer 50a, 50b is formed on the distal end
14, and the masking material/layer is removed to expose the
electrode 18a, 18b.
[0062] Additionally, the insulating member or layer 50 may be
applied by insert-molding, coating followed by etching, scribing or
cutting to define the windows 52, or selective vapor deposition of
insulative materials to form a patterned layer that defines one or
more windows 52.
[0063] In the embodiment shown in FIG. 2B (and steps described in
FIG. 3B and above), the insulating member or layer 52a is
substantially level or coextensive with the outer diameter of the
remaining length of the lead body 12b. A step is formed at the
distal end 14 to allow formation of the insulating member or layer
52a to be coextensive with lead body 12a, and wherein the outer
diameter of the distal end 14 is substantially the same as the
outer diameter of the lead body 12a.
[0064] With reference to FIGS. 6A and 6B, the lead 10 of the
present invention may incorporate a marking or orientation system,
which provides a mechanism to orient the directional lead 10 while
the lead is implanted in the body. Such orientation is desired to
orient the lead to take advantage of the directional nature of the
electrodes to target a desired area.
[0065] As shown in FIG. 6A, the marking system includes a marker
(or marking band) 600. The marker 600 is positioned at a first
location and affixed or attached to, or integrated with, the lead
10. In the embodiment shown, the marker 600 includes an electrode
(or electrode-type) band (similar to electrodes 18) with a notch
602. The marker 600 is constructed of radio-opaque material that
provides a marker, which is visible through the body when using a
fluoroscope or X-ray device, or other similar or like devices,
while the lead is within a body. The radio-opaque material may be a
composition of platinum-iridium, or some other conductive or
metallic material. The notch 602 depicted is an opening or window
in the marker 600 where no radio-opaque material exists. As will be
understood, the marker 600 may be integrated within the lead 10
during construction of the lead, in the methods as described above,
or may be affixed, constructed or attached through additional
steps.
[0066] The marker 600 is tubular in shape and resembles a band
electrode. The notch 602 of the marker 600 typically extends
circumferentially with the lead body for a predetermined distance
or arc. In the embodiment shown, the notch 602 extends arcuately
for a length equal to about 180 degrees (about one-half way
around), or a 180 degree arc. In other embodiments, any length/arc
may be chosen sufficient to provide the functionality described
herein, including ranging from 90 degrees to 270 degrees or
forty-five degrees. Moreover, the axial length of the marker 600
may be any desired length sufficient to obtain the desired results,
but is typically about the same or shorter than axial length of the
electrodes 18.
[0067] To function effectively as a marking or orientation system
for orienting/positioning the lead within a body for directional
stimulation, the notch (or the portion "non-visible" via
fluoroscopy or X-ray) 602 of the marker 600 is oriented or fixed in
a predetermined relation with respect to the exposed portions of
the electrodes 18. As will be appreciated, depending on the shape
and directional orientation of the electrodes 18 (exposed
portions), and the marker 600 (notch), the marker 600 and
electrodes 18 are fixed generally at a circumferential distance
from each other. In the example illustrated in FIG. 6A, the marker
600 is positioned about ninety degrees offset from the electrodes
18. Knowledge of the fixed position of the marker 600 relative to
the electrodes 18 and window 52 provides a marking or orientation
system operable to allow a practitioner implanting the directional
lead within a body to place the lead and orient the windows
contained on the lead at the desired location and with the desired
directional orientation.
[0068] While any offset positioning may be used, it appears that an
offset of ninety degrees (plus or minus) may be more effective, as
it is easier to view and comprehend such relative positioning with
respect to two components.
[0069] Now with reference to FIG. 6B, there is illustrated an
enlarged perspective view of the marker 600 showing the notch 602.
The marker has a similar configuration as the band electrode with a
section or portion (602) removed.
[0070] Those of ordinary skill in the art will readily understand
that, when the lead with the marker 602 of the present invention is
implanted, the marker silhouette viewable through utilization of a
detecting device (e.g., fluoroscope or X-ray device) will show
different configurations depending on the orientation of the lead.
For example, assuming the notch size is approximately one-half the
band, when the notch is facing directly toward or away from the
detecting device, a complete band will be visible. Similarly, if
facing directly perpendicular to the detecting device, the visible
configuration will provide information as to the orientation of the
lead (i.e. a C-shape). Therefore, the marker 600 will allow a
clinician the ability to orient the lead in a fashion so as to
direct the stimulation in a desired direction (using the
directional electrodes).
[0071] The marker 600 is capable of recognition in the body through
the use of a fluoroscope, radiation, or other similar or like
technology. This allows a medical professional to determine the
orientation of the directional electrodes of the lead relative to
the targeted tissue. The marker(s) band within the lead allows a
medical professional to quickly and easily determine the relative
position of the electrode(s) 18a, 18b within lead 10 (see FIGS. 2A,
2B).
[0072] As will be appreciated, more than one marker 602 (not shown)
may be optionally utilized. Further, the sizes, shapes and
configurations of the marker 600 and the notch 602 may vary. While
the embodiment of the marker 600 in FIGS. 6A and 6B is configured
with a notch, another configuration may include only a single arc
section of material (in the form of a semi-circle, without portions
that extend completely about the lead). Another configuration (not
shown) includes two diametrically opposed notches or holes in the
marker material. In this way, orientation of the marker can be
determined due to the alignment of the notches, which will become
visible when substantially aligned.
[0073] It will be understood by those skilled in the art that the
marking or orientation system may include a single marker, or
multiple markers, each of the marker(s) having some recognition
attribute (recognizable by some means). Such recognition attributes
include radio-opaque or radiopaic and structural (e.g., notch or
groove), and the system may utilize multiple markers each utilizing
a different attribute to create a marking system for orienting the
implanted lead (or simply for determining the orientation).
[0074] One characteristic of the embodiment shown in FIG. 2B (and
in FIG. 2A when the insulating member 50a extends substantially the
length of the lead 10) is that during lead insertion (via a
needle), there are times when the lead may be pulled back through
the needle. In such case, having an insulating member or layer that
has an outer diameter greater than the overall diameter of the lead
body, may result in undesirable cutting (damage) or catching of the
lead by the edge of the needle as it is removed (in order to
re-insert or reposition the lead through the needle).
[0075] However, even with leads having substantially the same outer
diameter, prior art percutaneous insertion leads will tend to cut
or damage a lead when it is pulled back through the needle.
[0076] Now with reference to FIG. 7, there is illustrated a typical
prior art percutaneous insertion needle 700. The needle 700
includes a needle body 702 (with a lumen therethrough), a proximate
end 704 (providing for insertion of a lead/catheter and/or stylet
or other inserted device), a distal end 710, an introducer portion
706 with a slight curvature, and an orifice 708. Examples of such
needles are epidural, Touhy and modified Touhy needles. The
functionality and structure of these devices is well known to those
skilled in the art and, therefore, no further description will be
provided herein.
[0077] With reference to FIG. 8, there is shown a needle 800 in
accordance with the present invention. The needle 800 includes a
needle body 802 (with a lumen therethrough), a proximate end 804
(providing for insertion of a lead/catheter and/or stylet or other
inserted device), a distal end 810, an introducer portion 806 with
a slight curvature, and an orifice 808. The needle 800 further
includes a lip or flare 812 positioned proximate the heel edge of
the orifice 808 of the needle 800. As used herein, the term "lead"
includes catheters or other electrical or drug delivery devices
typically inserted percutaneously through the needle.
[0078] Now referring to FIGS. 9A and 9B, there is illustrated a
partial side view and partial tip view, respectively, showing the
distal end tip portion of the needle of FIG. 8. The radius of
curvature R for the introducer portion 806 is about 1 inch (in
another embodiment is less than about 2 inches), and those skilled
in the art will understand that other curvatures may be
implemented. The lip or flare section 812 on a heel portion 814 of
the orifice 808 includes a slight curvature. In one embodiment, the
radius of curvature R1 of the section 812 is less than the radius
of curvature R for the introducer portion 806. In another
embodiment, the radius of curvature R1 is approximately 0.1 inches
or less. This provides for the raised lip or flare at 812 that
provides for a "funneling" or "channeling" location within the
needle, as shown more fully in FIG. 11, to help guide the lead back
into the needle in a manner such that the lead will not score or
cut on the lip or flare (heel portion) if the lead is pulled back
through the needle. The cross-section area at the lip portion is
greater than the cross-section area at an adjacent body portion
(towards the proximate end of the needle), or as differently
described, the inner diameter of the needle at the lip portion is
greater than the inner diameter of the needle at an adjacent body
portion (towards the proximate end of the needle).
[0079] As described above, the configuration of the heel edge of
the needle 800 as shown by the lip or flare section 812 helps
reduces the likelihood that a lead/catheter inserted through the
needle 800 (extending through the orifice 808) will become cut or
damaged in the event the lead/catheter is pulled back through the
needle toward the proximal end of the needle.
[0080] An orifice edge of the introducer section 808 further
includes a radius of curvature R2 of approximately 0.05 inches.
[0081] FIG. 8 illustrates one embodiment of the needle 800 usable
to insert and place any of the above-described inventive leads, or
any prior art leads. The needle 800 defines an interior path that
ultimately receives and guides a lead into an epidural space or
other desired location within a body. Typically, both the needle
800 and stylet (not shown) are used in combination to facilitate
penetration through human tissue to the desired location.
[0082] In one embodiment of an implantable procedure, a small
incision is first made in a body using a scalpel at the desired
site of insertion. Making an initial incision prevents the
application of excess force to the tip of the needle 800 and
further avoids the undesirable introduction of dermal matter into
the location. The needle 800 is introduced through the incision at
an angle that allows passage of the needle 200 between vertebral
bodies. Once the distal end 810 of the needle 200 is positioned
within and opens into the desired location (typically, epidural
space), a lead is inserted.
[0083] Now referring to FIGS. 4 and 5, there are shown two
embodiments of a stimulation system 200, 300 in accordance with the
present invention. The stimulation systems generate and apply a
stimulus to a tissue or to a certain location of a body. In general
terms, the system 200, 300 includes a stimulation or energy source
210, 310 and a lead 10 for application of the stimulus. The lead 10
shown in FIGS. 4 and 5 is the lead 10 of the present invention.
[0084] As shown in FIG. 4, the stimulation system 200 includes the
lead 10 that is coupled to the stimulation source 210. In one
embodiment, the stimulation source 210 includes an implantable
pulse generator (IPG). As is known in the art, an implantable pulse
generator (IPG) is capable of being implanted within the body (not
shown) that is to receive electrical stimulation from the
stimulation source 210. An exemplary IPG may be one manufactured by
Advanced Neuromodulation Systems, Inc., such as the Genesis.RTM.
System, part numbers 3604, 3608, 3609, and 3644.
[0085] As shown in FIG. 5, the stimulation system 300 includes the
lead 10 that is coupled to the stimulation source 310. The
stimulation source 310 includes a wireless receiver (not shown).
The stimulation source 310 may also be referred to as a wireless
receiver. As is known in the art, the stimulation source 310
comprising a wireless receiver is capable of being implanted within
the body (not shown) that is to receive electrical stimulation from
the wireless receiver 310. An exemplary wireless receiver 310 may
be those receivers manufactured by Advanced Neuromodulation
Systems, Inc., such as the Renew.RTM. System, part numbers 3408 and
3416.
[0086] The wireless receiver (not shown) within stimulation source
310 is capable of receiving wireless signals from a wireless
transmitter 320. The wireless signals are represented in FIG. 5 by
wireless link symbol 330. The wireless transmitter 320 and a
controller 340 are located outside of the body that is to receive
electrical stimulation from the stimulation source 310. A user of
the stimulation source 310 may use the controller 340 to provide
control signals for the operation of the stimulation source 310.
The controller 340 provides control signals to the wireless
transmitter 320. The wireless transmitter 320 transmits the control
signals (and power) to the receiver in the stimulation source 310,
and the stimulation source 310 uses the control signals to vary the
signal parameters of the electrical signals that are transmitted
through lead 10 to the stimulation site. An exemplary wireless
transmitter 320 may be those transmitters manufactured by Advanced
Neuromodulation Systems, Inc., such as the Renew.RTM. System, part
numbers 3508 and 3516.
[0087] As will be appreciated, the contact electrodes 20 are not
visible in FIG. 4 (or FIG. 5) because the contact electrodes 20 are
situated within a receptacle (not shown) of the stimulation source
210, 310. The contact electrodes 20 are in electrical contact with
a generator (not shown) of electrical signals within the
stimulation source 210, 310. The stimulation source 210, 310
generates and sends electrical signals via the lead 10 to the
electrodes 18. Understandably, the electrodes 18 are located at a
stimulation site (not shown) within the body that is to receive
electrical stimulation from the electrical signals. A stimulation
site may be, for example, adjacent to one or more nerves in the
central nervous system (e.g., spinal cord). The stimulation source
210, 310 is capable of controlling the electrical signals by
varying signal parameters (e.g., intensity, duration, frequency) in
response to control signals that are provided to the stimulation
source 210, 310.
[0088] It may be advantageous to set forth definitions of certain
words and phrases that may be used within this patent document: the
terms "include" and "comprise," as well as derivatives thereof,
mean inclusion without limitation; the term "or," is inclusive,
meaning and/or; the phrases "associated with" and "associated
therewith," as well as derivatives thereof, may mean to include, be
included within, interconnect with, contain, be contained within,
connect to or with, couple to or with, be communicable with,
cooperate with, interleave, juxtapose, be proximate to, be bound to
or with, have, have a property of, or the like; and if the term
"controller" is utilized herein, it means any device, system or
part thereof that controls at least one operation, such a device
may be implemented in hardware, firmware or software, or some
combination of at least two of the same. It should be noted that
the functionality associated with any particular controller may be
centralized or distributed, whether locally or remotely.
[0089] Although the present invention and its advantages have been
described in the foregoing detailed description and illustrated in
the accompanying drawings, it will be understood by those skilled
in the art that the invention is not limited to the embodiment(s)
disclosed but is capable of numerous rearrangements, substitutions
and modifications without departing from the spirit and scope of
the invention as defined by the appended claims.
* * * * *