U.S. patent application number 10/115302 was filed with the patent office on 2003-10-23 for method and apparatus for fixating a pacing lead of an implantable medical device.
Invention is credited to Bass, Wayne R., Bjorklund, Vicki L., Hess, Douglas N., Hine, Douglas S., Lokhoff, Nicolaas M., Morris, Mary M., Sandstrom, Richard D., Sommer, John L..
Application Number | 20030199961 10/115302 |
Document ID | / |
Family ID | 28789816 |
Filed Date | 2003-10-23 |
United States Patent
Application |
20030199961 |
Kind Code |
A1 |
Bjorklund, Vicki L. ; et
al. |
October 23, 2003 |
Method and apparatus for fixating a pacing lead of an implantable
medical device
Abstract
A method and apparatus for dynamically fixating and removing a
lead in a vasculature of a body. At least one segmenting means such
as a collar is disposed at a distal end of the lead forming a
deployable actuable segment adapted to dynamically assume an
engaging and retracted position. In an engaging position, the
actuable segment dynamically and varyingly adapts into a shape or
shapes to engage a vessel. In a retracted position the shape or
shapes collapse thus maintaining the original geometry of the lead
in the vasculature. The actuable segment assumes a deployed or
retracted position based on the flexural condition of the segment,
respectively.
Inventors: |
Bjorklund, Vicki L.; (Maple
Grove, MN) ; Hine, Douglas S.; (White Bear Lake,
MN) ; Sommer, John L.; (Coon Rapids, MN) ;
Hess, Douglas N.; (Maple Grove, MN) ; Sandstrom,
Richard D.; ( Scandia, MN) ; Bass, Wayne R.;
(Coon Rapids, MN) ; Morris, Mary M.; (Mounds View,
MN) ; Lokhoff, Nicolaas M.; (Kerkrade, NL) |
Correspondence
Address: |
MEDTRONIC, INC.
710 MEDTRONIC PARKWAY NE
MS-LC340
MINNEAPOLIS
MN
55432-5604
US
|
Family ID: |
28789816 |
Appl. No.: |
10/115302 |
Filed: |
April 3, 2002 |
Current U.S.
Class: |
607/126 |
Current CPC
Class: |
A61N 1/057 20130101;
A61N 2001/0585 20130101 |
Class at
Publication: |
607/126 |
International
Class: |
A61N 001/05 |
Claims
What is claimed:
1. An apparatus for fixating a lead disposed within a vessel,
comprising: a segment at a distal end of the lead; at least one
deployable lobe situated at the segment, the deployable lobe
adapted to assume a retracted position and an engaging position,
the engaging position engaging the at least one deployable lobe
with the vessel; and wherein the at least one deployable lobe
assumes the engaging position in response to the segment being
compressed and assumes the retracted position when the fixation
segment is not compressed.
2. The apparatus of claim 1, wherein the at least one deployable
lobe is formed between a pair of elongated, substantially parallel
slits in the segment.
3. The apparatus of claim 1, wherein the compression of the segment
causes the deployable lobe to extend outwardly from an outer
surface of the segment.
4. The apparatus of claim 1, wherein by not compressing the segment
causes the deployable lobe to retract and become substantially
parallel to an outer surface of the fixation segment.
5. The apparatus of claim 3, wherein compression of the segment
causes the deployable lobe to extend outwardly from the outer
surface of the fixation segment and form an angular shape having an
apex.
6. The apparatus of claim 5, wherein the apex of the angular shape
formed by the deployable lobe engages the vessel, thereby
substantially fixating the lead within the vessel.
7. The apparatus of claim 1, further comprising: push tubing
surrounding the lead and secured to the segment at one end thereof;
and an anchor member for securing an opposite end of the segment to
the lead; and wherein pushing of the push tubing toward the segment
causes compression of the segment against the anchor member.
8. An apparatus for fixating a lead disposed within a vessel,
comprising: at least one deployable lobe situated on a distal
portion of the lead, the deployable lobe adapted to assume a
retracted position and an engaging position, the engaging position
engaging the at least one deployable lobe with the vessel; a
flexible material covering a portion of an outer surface of the
lead; and wherein the at least one deployable lobe assumes the
engaging position by deforming of the flexible material a segment
from the lead at the portion of the outer surface and assumes the
retracted position by rectifying said deforming of the segment.
9. The apparatus of claim 8, wherein the at least one deployable
lobe comprises an expandable spring within the lead, and wherein
the spring stretches the flexible material outwardly from the lead
when the spring assumes the engaging position.
10. The apparatus of claim 9, wherein the expandable spring is
expanded to stretch the flexible material by rotating a conductor
that is disposed within the lead.
11. The apparatus of claim 9, wherein the expandable spring and
flexible material engage the vessel when assuming the engaging
position, thereby substantially fixating the lead within the
vessel.
12. The apparatus of claim 8, wherein the flexible material
comprises at least one of polyisoprene, polyurethane, and
silicone.
13. The apparatus of claim 8, wherein the at least one deployable
lobe comprises a stent within the lead, and wherein the stent
stretches the flexible material outwardly from the lead when the
stent assumes the engaging position.
14. The apparatus of claim 13, wherein the stent and flexible
material engage the vessel when assuming the engaging position,
thereby substantially fixating the lead within the vessel.
15. The apparatus of claim 13, wherein the stent is expanded to
stretch the flexible material by rotating a conductor that is
disposed within the lead.
16. The apparatus of claim 8, wherein the at least one deployable
lobe comprises a flange within the lead, and wherein the flange
bends to form an angular shape that stretches the flexible material
outwardly from the lead when the flange assumes the engaging
position.
17. The apparatus of claim 16, wherein the flange bends to form the
angular shape by pushing a wire attached to one end thereof.
18. The apparatus of claim 16, wherein the flange and flexible
material engage the vessel when assuming the engaging position,
thereby substantially fixating the lead within the vessel.
19. The apparatus of claim 8, wherein the at least one deployable
lobe comprises a flange that is attached to the lead at one end
thereof by a hinge member, and wherein the flange rotates outwardly
about the hinge member and stretches the flexible material
outwardly from the lead when the flange assumes the engaging
position.
20. The apparatus of claim 19, wherein the flange rotates outwardly
about the hinge member by pushing an outer tubing that surrounds
the lead underneath the flange.
21. The apparatus of claim 20, wherein an inner edge of the flange
is sloped to facilitate the outward rotation of the flange when the
outer tubing is engaged therewith.
22. An apparatus for fixating a lead disposed within a vessel,
comprising: at least one deployable lobe situated on a distal
portion of the lead, the deployable lobe adapted to assume a
retracted position and an engaging position, the engaging position
engaging the at least one deployable lobe with the vessel; a lumen
coupled to the deployable lobe, and adapted to extend the
deployable lobe to the engaging position; and wherein the at least
one deployable lobe assumes the engaging position by extending
outwardly from an outer surface of the lead.
23. The apparatus of claim 22, wherein the deployable lobe takes
the form of a balloon-like material.
24. The apparatus of claim 22, wherein the deployable lobe is
extended outwardly from the outer surface of the lead by inflation
of the lobe via the lumen.
25. The apparatus of claim 24, wherein the deployable lobe is
extended outwardly from the outer surface of the lead by inflation
of the lobe by injecting a gas or liquid into the lumen.
26. The apparatus of claim 22, wherein the deployable lobe engages
the vessel when assuming the engaging position, thereby
substantially fixating the lead within the vessel.
27. An apparatus for fixating a lead disposed within a vessel, the
lead including an electrical conductor surrounded by a conductor
tubing and an outer tubing that is slideably received over the
conductor tubing, the apparatus comprising: at least one deployable
lobe situated on a distal portion of an outer surface of the
conductor tubing of the lead, the deployable lobe adapted to assume
a retracted position and an engaging position, the engaging
position engaging the at least one deployable lobe with the vessel;
a recessed slot formed lengthwise within an inner surface of the
outer tubing; and wherein the at least one deployable lobe assumes
the retracted position when the recessed slot formed within the
outer tubing is in alignment with the deployable lobe and is
slideably received within the recessed slot, and assumes an
engaging position by extending outwardly from the outer surface of
the conductor tubing when the deployable lobe is not in alignment
with the recessed slot.
28. The apparatus of claim 27, wherein the deployable lobe
comprises a flexible strip, and wherein each end of the flexible
strip is fixedly attached to the outer surface of the conductor
tubing.
29. The apparatus of claim 27, wherein the electrical conductor is
rotated within the outer tubing to align or unalign the deployable
lobe with the recessed slot formed lengthwise within the inner
surface of the outer tubing.
30. The apparatus of claim 27, wherein the engaging position of the
deployable lobe is achieved by pushing the electrical conductor out
from the outer tubing until the deployable lobe is exposed from the
recessed slot, and rotating the electrical conductor until the
deployable lobe is not in alignment with the recessed slot formed
within the outer tubing.
31. The apparatus of claim 27, wherein the retracted position of
the deployable lobe is achieved by rotating the electrical
conductor until the deployable lobe is in alignment with the
recessed slot formed within the outer tubing and the deployable
lobe is slideably received within the recessed slot.
32. A method for fixating a lead disposed within a vessel,
comprising: providing a fixation segment surrounding the lead at a
distal end thereof; providing at least one deployable lobe situated
on the fixation segment, the deployable lobe adapted to assume a
retracted position and an engaging position, the engaging position
engaging the at least one deployable lobe with the vessel; and
compressing the fixation segment to have the at least one
deployable lobe assume the engaging position.
33. A method for fixating a lead disposed within a vessel,
comprising: providing at least one deployable lobe situated on a
distal portion of the lead, the deployable lobe adapted to assume a
retracted position and an engaging position, the engaging position
engaging the at least one deployable lobe with the vessel;
providing a flexible material covering a portion of an outer
surface of the lead; and extending the flexible material outwardly
from the lead at the portion of the outer surface when the at least
one deployable lobe assumes the engaging position.
34. A method for fixating a lead disposed within a vessel,
comprising: providing at least one deployable lobe situated on a
distal portion of the lead, the deployable lobe adapted to assume a
retracted position and an engaging position, the engaging position
engaging the at least one deployable lobe with the vessel; and
providing a lumen coupled to the deployable lobe, and adapted to
extend the deployable lobe to the engaging position by extending
outwardly from an outer surface of the lead.
35. A method for fixating a lead disposed within a vessel, the lead
including an electrical conductor surrounded by a conductor tubing
and an outer tubing that is slideably received over the conductor
tubing, the method comprising: providing at least one deployable
lobe situated on a distal portion of an outer surface of the
conductor tubing of the lead, the deployable lobe adapted to assume
a retracted position and an engaging position, the engaging
position engaging the at least one deployable lobe with the vessel;
forming a recessed slot lengthwise within an inner surface of the
outer tubing; and retracting the deployable lobe when the recessed
slot formed within the outer tubing is in alignment with the
deployable lobe and is slideably received within the recessed slot,
thereby assuming the retracted position; and extending the
deployable lobe outwardly from the outer surface of the conductor
tubing when the deployable lobe is not in alignment with the
recessed slot and is withdrawn therefrom, thereby assuming the
engaging position.
36. The method of claim 35 wherein a slip anti-coagulant (heparin)
coating is used on the conductor tubing.
37. The method of claim 35 wherein the lobes are annealed to enable
deployment in an engaging position.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to implantable medical
devices, and, more particularly, to a fixation mechanism for
securing a lead of the implantable medical device within a cardiac
vessel of a patient.
DESCRIPTION OF THE RELATED ART
[0002] Since their earliest inception some forty years ago, there
has been a significant advancement in body-implantable electronic
medical devices. Today, these implantable devices include
therapeutic and diagnostic devices, such as pacemakers,
cardioverters, defibrillators, neural stimulators, drug
administering devices, among others for alleviating the adverse
effects of various health ailments. Today's implantable medical
devices are also vastly more sophisticated and complex than their
predecessors, and are therefore capable of performing considerably
more complex tasks for reducing the effects of these health
ailments.
[0003] The implantable medical device is generally implanted within
the patient's body and a lead couples the implantable device to a
portion of the patient's body, such as the patient's heart, for
example. Typically, an electrode is provided at the distal end of
the lead, and it is adapted to be disposed at a desired site within
a cardiac vessel of the heart, such as a vein. The electrodes
typically sense cardiac activity and deliver electrical pacing
stimuli (i.e., therapeutic signals) to the patient's heart
depending on the sensed cardiac activity.
[0004] The pacing leads are commonly implanted within the cardiac
vessel with the aid of a stylet that is positioned within a lumen
in the lead. If the electrode residing on the distal end of the
pacing lead becomes dislodged after implantation within the cardiac
vessel, the electrode may not be able to properly sense the cardiac
activity of the patient and deliver the electrical pulsing stimuli
to the desired area of the patient's heart. If the electrode
becomes dislodged from the desired location within the patient's
cardiac vessel, a significant amount of time and expense may occur
to have the dislodged electrode replanted within the desired site
of the cardiac vessel. Moreover, upon dislodgment of the electrode,
the patient may be subjected to serious health risks as a result of
the electrode not being able to properly sense cardiac activity of
the patient and/or deliver a proper therapy to the desired site
within the patient's heart.
[0005] The present invention is directed to overcoming, or at least
reducing the effects of, one or more of the problems set forth
above.
SUMMARY OF THE INVENTION
[0006] In one aspect of the present invention, an apparatus for
fixating a lead disposed within a vessel is provided. The apparatus
comprises a fixation segment of the lead at a distal end thereof,
and at least one deployable lobe situated on the fixation segment.
The deployable lobe is adapted to assume a retracted position and
an engaging position, where the engaging position engages the at
least one deployable lobe with the vessel. The at least one
deployable lobe assumes the engaging position in response to the
fixation segment being compressed and assumes the retracted
position when the fixation segment is not compressed.
[0007] In another aspect of the invention, an apparatus for
fixating a lead disposed within a vessel is provided. The apparatus
comprises at least one deployable lobe situated on a distal portion
of the lead. The deployable lobe is adapted to assume a retracted
position and an engaging position, where the engaging position
engages the at least one deployable lobe with the vessel. The
apparatus further comprises a flexible material covering a portion
of an outer surface of the lead. The at least one deployable lobe
assumes the engaging position by extending outwardly from the lead
at the portion of the outer surface by stretching the flexible
material.
[0008] In another aspect of the invention, an apparatus for
fixating a lead disposed within a vessel is provided. The apparatus
comprises at least one deployable lobe situated on a distal portion
of the lead. The deployable lobe is adapted to assume a retracted
position and an engaging position, where the engaging position
engages the at least one deployable lobe with the vessel. A lumen
is coupled to the deployable lobe and is adapted to extend the
deployable lobe to the engaging position. The at least one
deployable lobe assumes the engaging position by extending
outwardly from an outer surface of the lead.
[0009] In another aspect of the invention, an apparatus for
fixating a lead disposed within a vessel is provided. The lead
includes an electrical conductor surrounded by a conductor tubing,
and an outer tubing that is slideably received over the conductor
tubing. The apparatus comprises at least one deployable lobe
situated on a distal portion of an outer surface of the conductor
tubing of the lead, the deployable lobe adapted to assume a
retracted position and an engaging position, the engaging position
engaging the at least one deployable lobe with the vessel. A
recessed slot is formed lengthwise within an inner surface of the
outer tubing. The at least one deployable lobe assumes the
retracted position when the recessed slot formed within the outer
tubing is in alignment with the deployable lobe and is slideably
received within the recessed slot, and assumes an engaging position
by extending outwardly from the outer surface of the conductor
tubing when the deployable lobe is not in alignment with the
recessed slot.
[0010] In another aspect of the invention a method for fixating a
lead disposed within a vessel is provided. The method includes
providing a fixation segment surrounding the lead at a distal end
thereof, and providing at least one deployable lobe situated on the
fixation segment. The deployable lobe is adapted to assume a
retracted position and an engaging position, where the engaging
position engages the at least one deployable lobe with the vessel.
The fixation segment is compressed to have the at least one
deployable lobe assume the engaging position.
[0011] In another aspect of the present invention a method for
fixating a lead disposed within a vessel is provided. The method
includes providing at least one deployable lobe situated on a
distal portion of the lead. The deployable lobe is adapted to
assume a retracted position and an engaging position, where the
engaging position engages the at least one deployable lobe with the
vessel. A flexible material is provided to cover a portion of an
outer surface of the lead. The flexible material is extended
outwardly from the lead at the portion of the outer surface when
the at least one deployable lobe assumes the engaging position.
[0012] In another aspect of the present invention, a method for
fixating a lead disposed within a vessel is provided. The method
includes providing at least one deployable lobe situated on a
distal portion of the lead. The deployable lobe is adapted to
assume a retracted position and an engaging position, where the
engaging position engages the at least one deployable lobe with the
vessel. The method further includes providing a lumen coupled to
the deployable lobe, and adapted to extend the deployable lobe to
the engaging position by extending outwardly from an outer surface
of the lead.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention may be understood by reference to the
following description taken in conjunction with the accompanying
drawings, in which the leftmost significant digit(s) in the
reference numerals denote(s) the first figure in which the
respective reference numerals appear, and in which:
[0014] FIG. 1 schematically illustrates an implantable medical
device, in the form of a pacemaker, according to one embodiment of
the present invention;
[0015] FIGS. 2A, 2A', 2B-D show perspective views of a distal
portion of a lead having a deployable lobe for fixating the lead to
a vessel according to one embodiment of the present invention;
[0016] FIGS. 3A-C show perspective views of the distal portion of
the lead having a deployable lobe for fixating the lead to the
vessel in accordance with another embodiment of the present
invention;
[0017] FIGS. 4A-B show a side view perspective of the distal
portion of the lead employing an expandable spring for fixating the
lead to the vessel in accordance with another embodiment of the
present invention;
[0018] FIGS. 5A-B show a side view perspective of the distal
portion of the lead employing a stent for fixating the lead to the
vessel in accordance with another embodiment of the present
invention;
[0019] FIGS. 6A-B show a side view perspective of the distal
portion of the lead employing a balloon for fixating the lead to
the vessel in accordance with another embodiment of the present
invention;
[0020] FIGS. 7A-C show a side view perspective of the distal
portion of the lead employing a pair of flanges for fixating the
lead to the vessel in accordance with another embodiment of the
present invention; and
[0021] FIGS. 8A-D show perspective views of a distal portion of a
lead having a deployable lobe for fixating the lead to a vessel
according to another embodiment of the present invention.
[0022] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof have been shown
by way of example in the drawings and are herein described in
detail. It should be understood, however, that the description
herein of specific embodiments is not intended to limit the
invention to the particular forms disclosed, but, on the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the invention
as defined by the appended claims.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0023] Illustrative embodiments of the invention are described
below. In the interest of clarity, not all features of an actual
implementation are described in this specification. It will of
course be appreciated that in the development of any such actual
embodiment, numerous implementation-specific decisions must be made
to achieve the developers' specific goals, such as compliance with
system-related and business-related constraints, which will vary
from one implementation to another. Moreover, it will be
appreciated that such a development effort might be complex and
time-consuming, but would nevertheless be a routine undertaking for
those of ordinary skill in the art having the benefit of this
disclosure.
[0024] Turning now to the drawings, and specifically referring to
FIG. 1, an implantable medical device (IMD) system 100 is shown in
accordance with one embodiment of the present invention. The IMD
system 100 includes an implantable medical device 105 that has been
implanted in a patient 107. In accordance with the illustrated
embodiment of the present invention, the implantable device 105
takes the form of a pacemaker for regulating the patient's heart
rhythm. Although the implantable device 105 will be discussed in
the form of a pacemaker, it will be appreciated that the
implantable device 105 may alternatively take the form of a
cardioverter, defibrillator, neural stimulator, drug administering
device, and the like without departing from the spirit and scope of
the present invention.
[0025] The implantable device 105 is housed within a hermetically
sealed, biologically inert outer housing or container, which may
itself be conductive so as to serve as an electrode in the
pacemaker's pacing/sensing circuit. One or more pacemaker leads,
which are collectively identified by reference numeral 110, are
electrically coupled to the implantable device 105 and extend into
the patient's heart 112 through a vessel 113, such as a vein. The
leads 110 are coupled to the implantable medical device 105 via a
connector block assembly 115. Disposed generally near a distal end
of the leads 110 are one or more exposed conductive electrodes 117
for sensing cardiac activity and/or delivering electrical pacing
stimuli (i.e., therapeutic signals) to the heart 112. The distal
end of the lead 110 may be deployed in the ventricle, atrium,
coronary sinus, or a cardiac vessel of the heart 112.
[0026] Turning now to FIGS. 2A and 2A', a more detailed
representation of the distal end of the lead 110 is shown in
accordance with one embodiment of the present invention. The lead
110 comprises a flexible electrical conductor 205 for sending
diagnostic signals received via the electrode 117 (that may be
mounted on the terminal end of the lead 110) to the implantable
device 105, and/or for delivering therapeutic signals to the
patient via the electrode 117. In one embodiment, the electrical
conductor 205 may include tightly coiled stainless steel or a
platinum filament. It will be appreciated, however, that the
electrical conductor 205 may be constructed from various other
suitable materials without departing from the spirit and scope of
the present invention.
[0027] In accordance with one embodiment of the present invention,
the electrical conductor 205 is covered by an electrically
insulated sheath or conductor tubing 215 to protect the electrical
conductor 205 from bodily fluids of the patient, and to
electrically insulate the conductor 205. In one embodiment, the
conductor tubing 215 may be constructed from polyurethane. It will
be appreciated, however, that the conductor tubing 215 may be
constructed from various other materials, such as silicone, for
example, without departing from the spirit and scope of the present
invention.
[0028] In accordance with the illustrated embodiment, a fixation
mechanism 220 is provided on the mid or distal portion of the lead
110 to hold the lead 110 substantially stationary within the
cardiac vessel of the patient when disposed therein. According to
one embodiment, the fixation mechanism 220 comprises a fixation
segment 230 that engages and surrounds the conductor tubing 215 of
the lead 110. In accordance with the illustrated embodiment, the
fixation segment 230 may be constructed of silicone, polyurethane,
or the like.
[0029] In accordance with one embodiment of the present invention,
the fixation segment 230 comprises one or more deployable lobes 240
that are formed lengthwise on the segment 230 by a pair of
elongated, parallel cuts or slits 245 made within the fixation
segment 230. That is, the deployable lobe 240 is formed between the
elongated, substantially parallel slits 245 made within the
fixation segment 230 that surrounds the conductor tubing 215. The
spacing between the two parallel slits 245 formed within the
fixation segment 230 generally defines the width of the deployable
lobe 240 formed therebetween. Accordingly, the rigidity of the
deployable lobe 240 may be increased by increasing the width of the
deployable lobe 240 (i.e., increasing the distance between the
parallel slits 245). Additionally, the rigidity of the lobe 240 may
be increased by increasing the thickness of the fixation segment
230 that surrounds the conductor tubing 215. Furthermore, the
rigidity of the lobe 240 may be altered by using different types of
materials for the fixation segment 230. In one embodiment, the end
portions of the pair of parallel slits 245 formed within the
fixation segment 230 may be joined by a circular cut 250 (within
the segment 230) so as to reduce the likelihood of the slits 245
from spreading or expanding along the fixation segment 230.
[0030] In accordance with one embodiment of the present invention,
push tubing 260 is disposed around the conductor tubing 215 of the
lead 110, and is attached to the fixation segment 230 at one end
thereof. At the other end of the fixation segment 230, an anchor
member 265 is affixed to the conductor tubing 215 to substantially
prevent movement of the fixation segment 230 beyond the anchor
member 265 (i.e., the anchor member 265 substantially prevents the
fixation segment 230 from sliding further down the distal end of
the lead 110). In one embodiment, the push tubing 260 may be used
to apply compression of the fixation segment 230 against the anchor
member 265, by advancing the push tubing 260 toward the distal end
of the lead 110. The pushing action on the fixation segment 230
causes the segment 230 to become compressed, thus causing the
extension of the deployable lobe 240 outwardly from the outer
surface of the fixation segment 230. In an alternative embodiment,
the push tubing 260 may be held stationary while the compression of
the fixation segment 230 is accomplished by withdrawing the
conductor tubing 215 toward the proximal end of the lead 110.
[0031] Prior to the lead 110 being placed within a cardiac vessel
of the patient, the deployable lobe 240 assumes a retracted
position when there is substantially no compression on the fixation
segment 230 by the push tubing 260. In the retracted position, the
deployable lobe 240 is substantially flat (i.e., not extended
outwardly) along the surface of the fixation segment 230. When the
lead 110 is placed within the desired site within the cardiac
vessel of the patient, the push tubing 260 is pushed toward the
distal end of the lead 110. The pushing of the push tubing 260
causes compression of the fixation segment 230 against the anchor
member 265, thereby causing the deployable lobe 240 to extend
outwardly or protrude from the surface of the fixation segment 230
by assuming an angular flexure or "boomerang" shape (as illustrated
in FIG. 2A). In one embodiment, the push tubing 260 may be held in
place by using a clip mechanism (not shown) on the proximal end of
the lead 110, thereby causing constant compression of the fixation
segment 230 by push tubing 260 until the clip mechanism is removed.
The deploying of the lobe 240 secures lead 110 within the cardiac
vessel and, thus, substantially prevents any movement of the lead
110 within the cardiac vessel.
[0032] In an alternative embodiment, lead 110 may have lobe 240
extended outwardly. In other words, in the resting state, lobes 240
would be deployed and during implant the tube is retracted or
withdrawn to flatten lobes 240 and relieve all the tension to
deploy the lead. When the lead is in a desired position the tubing
is pushed to dynamically shape lobes 240 forming an engaging
surface thereof. Further, multiple sets of lobes 240 may be located
on segments lead 110. In this embodiment, the lengths of segments
245 and the number of slits can vary from subsequent segments of
lead 110 on which a series of segments having lobes 240 are
located. In yet another embodiment, once the lead is deployed and
lobes 240 are in an engaged position, a temporary snap-on clip or
an anchoring sleeve may be used for chronic implant. Further, the
thickness "t" of lobes 240 could be varied between segments to
enable variability in rigidity and resistance at different segments
of lead 110 such that each lobe 240 provides varying degrees of
flexure.
[0033] In accordance with another embodiment of the present
invention, more than one deployable lobe 240 may be provided around
the circumference of the fixation segment 230 to further secure the
lead 110 within the cardiac vessel of the patient (as shown in FIG.
2B). For example, two deployable lobes 240 may be provided on
opposite sides of the fixation segment 230, three deployable lobes
240 may be provided at 120-degree separation points around the
circumference of the fixation segment 230, or four deployable lobes
240 may be provided at 90-degree separation points around the
circumference of the fixation segment 230. It will be appreciated
that any number of deployable lobes 240 may be placed around the
circumference of the fixation segment 230 to aid in securing the
lead 110 within the cardiac vessel. Furthermore, the spacing (i.e.,
the degree of separation) between the deployable lobes 240 around
the circumference of the fixation segment 230 may vary as well.
Additionally, the spacing between the deployable lobes 240 around
the circumference of the fixation segment 230 need not necessarily
be uniform, but may be placed at varying positions around the
circumference of the fixation segment 230. It will be further
appreciated that the lead 110 may also include two or more fixation
segments 230 that are disposed along the distal portion of the lead
110 in series. Accordingly, in this embodiment, each fixation
segment 230 will have its own set of deployable lobes 240.
[0034] According to the illustrated embodiment, the fixation
mechanism 220 may be further configured with a pair of platinum
rings 275 (FIG. 2A and 2A'), with each ring 275 disposed around
each end of the fixation segment 230 to indicate the degree with
which the deployable lobes 240 have been extended outwardly from
the surface of the fixation segment 230 under an x-ray examination,
for example. Accordingly, if the distance between the platinum
rings 275 is minimal, it will indicate that the lobes 240 are
deployed (extend outwardly from the surface of the fixation segment
230). In another embodiment, it will be appreciated that the
deployable lobes 240 of the fixation segment 230 may be constructed
with a radiopaque material, such as barium, platinum or tantalum
loaded rubber or polymer, so as to indicate the degree in which the
lobes 240 are deployed (in lieu of the platinum rings 275) without
departing from the spirit and scope of the present invention.
[0035] In accordance with one embodiment of the present invention,
a webbing material 280 may be attached between two consecutively
spaced lobes 240, and deployed when the lobes 240 extend outwardly
from the surface of the fixation segment 230 (as shown in FIG. 2C).
In another embodiment of the present invention, the electrode 117
may be disposed on the surface of the fixation segment 230 on a
side opposite of the deployable lobe 240 (FIG. 2D). In yet another
embodiment of the present invention, the terminal end of the lead
110 may be tapered and/or angled to aid in cardiac vessel selection
when the electrode 117 is disposed on the surface of the fixation
segment 230.
[0036] In accordance with another embodiment, a slip coating or
clot resistant slip coating may be applied to the inner surface of
the push tubing 260 or to the outer surface of the conductor tubing
215 to facilitate the sliding of the push tubing 260 over the
conductor tubing 215. According to one embodiment, the slip coating
may take the form of polyacrylamide PVP, or heparin polyacrylamide
hydrophilic coating, or polytetrafluroethylene (PTFE); however, it
will be appreciated that the slip coating or slip and
anti-coagulant combination coating may include various other
equivalent materials without departing from the scope of the
present invention.
[0037] Turning now to FIG. 3A, a fixation mechanism 300 for the
lead 110 is shown in accordance with another embodiment of the
present invention. In this particular embodiment, the distal end of
the lead 110 is configured with at least one deployable lobe 305
that may extend outwardly so as to protrude from the surface of the
conductor tubing 215. In one embodiment, the portion of the
conductor tubing 215 that covers the deployable lobe 305 comprises
a flexible material 310. In accordance with one embodiment, the
flexible material 310 is provided in the form of a balloon-like
material (such as polyisoprene, polyurethane, or silicone, for
example) that may stretch when the deployable lobe 305 is extended
outwardly from the surface of the conductor tubing 215. In one
embodiment, the deployable lobe 305 may be fixedly attached to the
electrical conductor 205 at a point 306, and provided with a joint
308 to permit the deployable lobe 305 to be substantially parallel
with the conductor tubing 215 when assuming a retracted position or
to extend outwardly or protrude from the surface of the conductor
tubing 215 by assuming an angular or "boomerang" shape (as depicted
in FIG. 3A). Alternatively, the deployable lobe 305 at the point
306 may be fixedly attached to a "stopper" mechanism (not shown)
disposed within the conductor tubing 215, as opposed to be attached
to the electrical conductor 205 (as shown in FIG. 3A), without
departing from the spirit and scope of the present invention. It
will further be appreciated, in another embodiment, that the
flexible material 310 may be omitted from covering the deployable
lobe 305 providing that the electrical conductor 205 is covered
with an insulating material to protect the conductor 205 from
bodily fluids of the patient.
[0038] In accordance with the illustrated embodiment, the conductor
tubing 215 comprises a bitumen tubing, with a first lumen 317
accommodating the electrical conductor 205 and a second lumen 318
for accommodating a push-pull wire 320 for actuating the deployable
lobe 305. Prior to the lead 110 being placed within a cardiac
vessel of the patient, the deployable lobe 305 is retracted by
pulling the push-pull wire 320 within the lumen 318. In the
retracted position, the deployable lobe 305 assumes a substantially
linear (or straightened) position, where the flexible material 310
is not extended outwardly from the conductor tubing 215 of the lead
110. When the lead 110 is placed at the desired site within the
cardiac vessel, the push-pull wire 320 is pushed within the lumen
318 toward the deployable lobe 305. The pushing of the push-pull
wire 320 within the lumen 318 causes the deployable lobe 305 to
extend outwardly or protrude from the surface of the conductor
tubing 215 by assuming an angular or "boomerang" shape. As the
deployable lobe 305 extends outwardly or protrudes from the surface
of the conductor tubing 215, the deployable lobe 305 stretches the
flexible material 310 resting thereon. The push-pull wire 320 is
pushed within the lumen 318 until the apex of the deployable lobe
305 engages the cardiac vessel, thereby securing the lead 110
within the cardiac vessel and, thus, substantially preventing any
movement of the lead 110 therein.
[0039] It will be appreciated that more than one deployable lobe
305 may be provided for the lead 110 to further secure the lead 110
within the cardiac vessel (as shown in FIG. 3B). For example, two
deployable lobes 305 may be provided on opposite sides of the lead
110, three deployable lobes 305 may be provided at 120-degree
separation points around the circumference of the lead 110, or four
deployable lobes 305 may be provided at 90-degree separation points
around the circumference of the lead 110. It will further be
appreciated that any number of deployable lobes 305 may be placed
around the circumference of the lead 110 to aid in securing the
lead 110 within the cardiac vessel. Furthermore, the spacing (i.e.,
the degree of separation) between the deployable lobes 305 around
the circumference of the lead 110 may vary as well. Additionally,
the rigidity of the deployable lobe 305 may be altered by
increasing or decreasing the width of the deployable lobe 305.
[0040] In accordance with one embodiment of the present invention,
the electrode 117 may be placed on the terminal end of the lead
110. In another embodiment, the electrode 117 may be placed on a
side of the lead 110 opposite from the side the deployable lobe 305
(in the case where one deployable lobe 305 is utilized) for the
fixation mechanism 300 (as shown in FIG. 3C).
[0041] Turning now to FIG. 4A, a fixation mechanism 400 for the
lead 110 is shown in accordance with another embodiment of the
present invention. In this particular embodiment, the distal end of
the lead 110 is configured with an expandable spring 405 that
encircles the electrical conductor 205 and is attached thereto by a
crimp bus 410. In accordance with the illustrated embodiment, the
expandable spring 405 is housed within a sleeve head 415 when the
expandable spring 405 assumes a retracted position. A portion of
the conductor tubing 215 includes the flexible material 310, such
as a stretchable balloon-like material, for example, which is
capable of expanding beyond the diameter of the conductor tubing
215 when the expandable spring 405 is pushed out from the sleeve
head 415.
[0042] Prior to the lead 110 being placed within a cardiac vessel
of the patient, the expandable spring 405 is retracted within the
sleeve head 415 by rotating the electrical conductor 205 in one
direction (e.g., counter-clockwise). In the retracted position, the
expandable spring 405 is compressed by the sleeve head 415, and the
flexible material 310 attached to the conductor tubing 215 is not
extended outwardly from the conductor tubing 215 of the lead 110
(i.e., the flexible material 310 has substantially the same
diameter as the conductor tubing 215). When the lead 110 is placed
at the desired site within the cardiac vessel, the electrical
conductor 205 is rotated in the other direction (e.g., clockwise),
which causes the expandable spring 405 to be ejected from the
sleeve head 415, and causes the spring 405 to expand the flexible
material 310 outwardly or protrude from the surface of the
conductor tubing 215 (as shown in FIG. 4B). As the expandable
spring 405 extends outwardly from the surface of the conductor
tubing 215, the spring 405 stretches the flexible material 310
resting thereon. The electrical conductor 205 is rotated until the
flexible material 310 engages the cardiac vessel, thereby securing
the lead 110 within the cardiac vessel 113 and, thus, substantially
preventing any movement of the lead 110 therein. In another
embodiment of the present invention, it will be appreciated that
the flexible material 310 may be placed underneath the expandable
spring 405 and the exposed spring 405 may be further used as an
electrode.
[0043] Turning now to FIG. 5A, a fixation mechanism 500 is shown in
accordance with another embodiment of the present invention. In
this particular embodiment, the distal end of the lead 110 is
configured with a stent 505 that may be expanded so as to protrude
from the surface of the conductor tubing 215 (as shown in FIG. 5B).
In one embodiment, the portion of the conductor tubing 215 that
covers the stent 505 comprises a flexible material 310. In
accordance with the illustrated embodiment, the flexible material
310 is provided in the form of a balloon-like material that may
stretch when the stent 505 is expanded outwardly from the surface
of the conductor tubing 215. In one embodiment of the present
invention, the stent 505 may take the form of a spring or coil. In
another embodiment, the stent 505 may be placed around the
conductor tubing 215 as opposed to being located within the
conductor tubing 215.
[0044] Prior to the lead 110 being placed within a cardiac vessel
of the patient, the stent 505 assumes an unexpanded state by
rotating the electrical conductor 205 in one direction (e.g., in a
counter-clockwise direction). In the unexpanded state, the diameter
of the stent 505 substantially matches the diameter of the
conductor tubing 215 of the lead 110, where the flexible material
310 is not stretched or expanded outwardly therefrom. When the lead
110 is placed within the cardiac vessel at the desired site, the
electrical conductor 205 is rotated in the opposite direction
(e.g., a clockwise direction), which causes the stent 505 to expand
in diameter. When the diameter of the stent 505 is expanded so as
to exceed the diameter of the conductor tubing 205, the flexible
material 310 resting thereon expands outwardly from the surface of
the conductor tubing 215. As the stent 505 expands or protrudes
from the surface of the conductor tubing 215, the stent 505
stretches the flexible material 310 resting thereon. The electrical
conductor 205 is rotated until the stent 505 and the flexible
material 310 resting thereon engages the cardiac vessel, thereby
securing the lead 110 within the cardiac vessel and substantially
preventing any movement of the lead 110 therein.
[0045] Turning now to FIG. 6A, a fixation mechanism 600 is shown in
accordance with another embodiment of the present invention. In
this particular embodiment, the distal end of the lead 110 is
configured with a deployable lobe 605 that may be expanded so as to
protrude from the outer surface of the conductor tubing 215. In one
embodiment, the deployable lobe 605 takes the form of a balloon
that resides on a side surface of the conductor tubing 215 of the
lead 110. In an alternative embodiment, the deployable lobe 605 may
be configured so as to surround the circumference of the lead 110.
In the illustrated embodiment, the conductor tubing 215 comprises a
bilumen tubing with a first lumen 612 accommodating the electrical
conductor 205 and a second lumen 613 with a port 620 used for
injecting a gas or liquid solution within the second lumen 613 to
expand the deployable lobe 605.
[0046] In accordance with one embodiment of the present invention,
prior to the lead 110 being placed within a cardiac vessel of the
patient, the deployable lobe 605 remains deflated on the
side-surface of the conductor tubing 215 of the lead 110 (as shown
in FIG. 6A). When the lead 110 is placed at a desired site within
the cardiac vessel, a liquid solution or gas is injected into the
lumen 613 via the port 620. In accordance with one embodiment, the
liquid solution may include saline and the gas may include carbon
dioxide. It will be appreciated, however, that various other liquid
solutions or gases may be used in lieu of the examples provided
without departing from the spirit and scope of the present
invention.
[0047] The injecting of the solution or gas within the lumen 613
causes the deployable lobe 605 to expand by filling the lobe 605
with the solution or gas and, thus, protrude or expand outwardly
from the outer surface of the conductor tubing 215 (as shown in
FIG. 6B). The solution or gas is injected through the port 620
until the deployable lobe 605 engages the cardiac vessel, thereby
securing the lead 110 within the cardiac vessel and, thus,
substantially preventing any movement of the lead 110 therein.
Subsequent to filling the deployable lobe 605 with the desired
amount of solution or gas, the port 620 may be removed, and the
lumen 613 may be sealed at the opening formed by the port 620 with
an adhesive or a self-sealing rubber grommet, for example, so as to
prevent any leakage of the solution or gas from the lumen 613 (and,
thus, preventing the deployable lobe 605 from deflating). In
accordance with another embodiment, the conductor tubing 215 may be
provided as a single lumen, and the deployable lobe 605 may be
provided with an opening (not shown) therein to inject a gas or
solution to inflate the deployable lobe 605. In this particular
embodiment, the opening within the deployable lobe 605 may then be
sealed to prevent any leakage of the gas or solution injected
therein, and, thus, substantially prevent deflation of the
deployable lobe 605.
[0048] In accordance with one embodiment, the electrode 117 may be
placed on the terminal end of the lead 110. In another embodiment,
the electrode 117 may be placed on a side of the lead 110 opposite
from the side the deployable lobe 605 on the lead 110.
[0049] Turning now to FIG. 7A, a fixation mechanism 700 for the
lead 110 is shown in accordance with another embodiment of the
present invention. In this particular embodiment, the distal end of
the lead 110 is configured with a pair of deployable lobes 705 that
may extend outwardly so as to protrude from the surface of the
conductor tubing 215. Although two deployable lobes 705 are shown
in FIG. 7A, it will be appreciated that only one or more than two
deployable lobes 705 may be disposed around the circumference of
the conductor tubing 215 without departing from the spirit and
scope of the present invention.
[0050] In one embodiment, the deployable lobe 705 may take the form
of a flange, and may be fixedly attached to a fixation segment 708
that is engaged with and encircles the conductor tubing 215. In one
embodiment, the deployable lobe 705 may be constructed out of a
plastic (e.g., silicon or some other polymer) or may be constructed
out of a metal. The deployable lobe 705 may be fixedly attached to
the fixation segment 708 at a pivot point 706 to allow the
deployable lobe 705 to be substantially parallel to the surface of
the conductor tubing 215 when assuming a retracted position or to
extend outwardly or protrude from the surface of the conductor
tubing 215 when the deployable lobe 705 is extended outwardly from
the surface of the conductor tubing 215 (i.e., when the deployable
lobe 705 rotates about the pivot point 706). Push tubing 710
surrounds the conductor tubing 215, and an end portion 715 of the
push tubing 710 engages an inner edge 717 of the deployable lobe
705.
[0051] In the illustrated embodiment, the inner edge 717 of the
deployable lobe 705 is sloped or tapered so as to cause the
deployable lobe 705 to eject outwardly when the end portion 715 of
the push tubing 710 slides between the outer surface of the
conductor tubing 215 and the inner edge 717 of the deployable lobe
705. That is, when the push tubing 710 is pushed towards the distal
end of the lead 110, the end portion 715 of the push tubing 710
slides between the outer surface of the conductor tubing 215 and
the inner edge 717 of the deployable lobe 705, thereby causing the
lobe 705 to rotate about the pivot point 706 and extend outwardly
from the outer surface of the conductor tubing 215.
[0052] When the push tubing 710 is pulled away from the distal end
of the lead 110, the deployable lobe 705 will retract until the
deployable lobe 705 is substantially parallel to the outer surface
of the conductor tubing 215. A slip coating may be applied to the
inner surface of the push tubing 710 or to the outer surface of the
conductor tubing 215 to facilitate the sliding of the push tubing
710 over the conductor tubing 215. According to one embodiment, the
slip coating may take the form of polyacrylamide or
polytetrafluroethylene (PrFE); however, it will be appreciated that
the slip coating may include various other materials. In the
illustrated embodiment, a molded transitional piece 720 is provided
between the deployable lobe 705 and the outer surface of the
conductor tubing 215 to provide a gradual transition between the
outer surface of the conductor tubing 215 and the deployable lobe
705.
[0053] In one embodiment, the end portion 715 of the push tubing
710 is tapered so as to facilitate the passage of the end portion
715 of the push tubing 710 underneath the deployable lobe 705.
Furthermore, the distal tip of the deployable lobe 705, which
engages the cardiac vessel when the lobe 705 is extended outwardly,
may be rounded to prevent damage to the cardiac vessel when engaged
therewith.
[0054] In one embodiment of the present invention, the deployable
lobe 705 may be covered by flexible material 310 that is attached
to the molded transition piece 720 and the push tubing 710 to
reduce the likelihood of tissue engrowth or bodily fluids of the
patient from ingressing underneath the push tubing 215. In
accordance with one embodiment, the flexible material 310 is
provided in the form of a balloon-like material (such as
polyisoprene, polyurethane, or silicone, for example) that may
stretch when the deployable lobe 705 is extended outwardly from the
surface of the conductor tubing 215. In accordance with an
alternative embodiment, it will be appreciated that the flexible
material 310 may be omitted, if so desired.
[0055] Prior to the lead 110 being placed within a cardiac vessel
of the patient, the deployable lobes 705 are retracted by pulling
the push tubing 710 away from the distal end of the lead 110. In
the retracted position, the deployable lobe 705 assumes a
substantially parallel position relative to the outer surface of
the conductor tubing 215, where the deployable lobe 705 is not
extended outwardly from the conductor tubing 215 of the lead 110.
When the lead 110 is placed at the desired site within the cardiac
vessel, the push tubing 710 is pushed toward the distal end of the
lead 110. This pushing action will cause the end portion 715 of the
push tubing 710 to slide under the deployable lobe 705, which will
cause the deployable lobe 705 to extend outwardly or protrude from
the surface of the conductor tubing 215 rotating outwardly about
the pivot point 706. As the deployable lobe 705 extends outwardly
or protrudes from the surface of the conductor tubing 215, the
deployable lobe 705 stretches the flexible material 310 resting
thereon. The pushing action of the push tubing 710 resumes until
the distal tip of the deployable lobe 705 engages the cardiac
vessel, thereby securing the lead 110 within the cardiac vessel. It
will be appreciated that the push tubing 710 may be held in place
with a clip mechanism (not shown), as discussed previously.
[0056] Turning now to FIG. 7B, the fixation mechanism 700 is shown
in accordance with another embodiment of the present invention. In
this particular embodiment, a unipolar lead 740 is surrounded by an
outer coil 745, and an outer tubing 750 surrounds the outer coil
745. By rotating the outer coil 745 in one direction (i.e.,
clockwise, for example), it will cause the end portion 752 of the
outer tubing 750 to go under the deployable lobe 705 and cause the
lobe 705 to extend outwardly from the outer tubing 750 when the
lobe 705 rotates about the pivot point 706 as illustrated in FIG.
7C. When it is desired to retract the lobe 705 such that it becomes
substantially parallel with the surface of the outer tubing 750,
the outer coil 745 may be rotated in the opposite direction (i.e.,
counter-clockwise, for example) to cause the outer tubing 750 to
disengage from underneath the deployable lobe 705, and thus cause
the lobe 705 to retract and become substantially parallel in
relation to the surface of the outer tubing 750.
[0057] Turning now to FIG. 8A, a fixation mechanism 800 for the
lead 110 is shown in accordance with another embodiment of the
present invention. In this particular embodiment, the distal end of
the lead 110 is configured with at least one deployable lobe 805
that may extend outwardly so as to protrude from the surface of a
conductor tubing 815 that surrounds an electrical conductor 810. In
one embodiment, the deployable lobe 805 takes the form of a
polyurethane strip material that may be fixedly attached to the
outer surface of the conductor tubing 815 at each end of the lobe
805. It will be appreciated that the deployable lobe 805, as
opposed to being provided in the form of a polyurethane strip, may
be constructed out of various other materials, such as silicone,
for example, without departing from the spirit and scope of the
present invention.
[0058] In accordance with the illustrated embodiment, the
electrical conductor 810 is slideably received within an opening of
an outer tubing 820 that surrounds the electrical conductor 810.
Referring to FIG. 8B, the deployable lobe 805 is shown in the
retracted position, where the lobe 805 is received within a
recessed slot 825 formed within the opening of the outer tubing
820. FIG. 8D illustrates a cross-sectional view of the outer tubing
820 with the opening 822 in which the electrical conductor 810 is
slideably received and the recessed slot 825 formed within the
opening 822 for receiving the deployable lobe 805.
[0059] Typically, the electrical conductor 810 will have a natural
tendency to remain retracted within the opening 822 of the outer
tubing 820. A stylet (not shown) is utilized to push out the
electrical conductor 810 from the opening 822 of the outer tubing
820, as is conventional in the art. FIG. 8C shows the electrical
conductor 810 extended from the opening 822 of the outer tubing
820. When the electrical conductor 810 is extended from the opening
822 of the outer tubing 820 using the stylet, the deployable lobe
805 on the outer surface of the conductor tubing 815 is exposed.
Once the deployable lobe 805 is exposed, the electrical conductor
810 may then be rotated either clockwise or counter-clockwise using
the stylet (not shown) within a recessed opening 830 of the
electrical conductor 810. By rotating the electrical conductor 810,
the deployable lobe 805 is no longer in alignment with the recessed
slot 825, and, therefore, may not be received within the slot.
Subsequent to rotation by the stylet, the electrical conductor 810
will attempt to retract within the opening 822 of the outer tubing
820, and because the deployable lobe 805 is not in alignment with
the recessed slot 825, will cause the deployable lobe 805 to extend
outwardly (or "buckle") from the outer surface of the conductor
tubing 815 (as illustrated in FIG. 8A).
[0060] Prior to the lead 110 being placed within a cardiac vessel
of the patient, the deployable lobe 805 assumes a retracted
position within the recessed slot 825 of the outer tubing 820 as
illustrated in FIG. 8B. In the retracted position, the deployable
lobe 805 assumes a substantially parallel position relative to the
outer surface of the conductor tubing 815, where the deployable
lobe 805 is not extended outwardly from the surface of the
conductor tubing 815 of the lead 110. When the lead 110 is placed
at the desired site within the cardiac vessel, a stylet (not shown)
is used to push out the electrical conductor 810 from the opening
822 of the outer tubing 820 until the deployable lobe 805 is
exposed (as illustrated in FIG. 8C). The stylet is then used to
rotate the electrical conductor 810 either clockwise or
counter-clockwise until the deployable lobe 805 is no longer in
alignment with the recessed slot 825 formed within the opening 822
of the outer tubing 820. When the stylet is removed, the electrical
conductor 810 will naturally attempt to retract within the opening
822 of the outer tubing 820. Because the deployable lobe 805 is not
in alignment with the recessed slot 825 of the opening 822 of the
outer tubing 820, the deployable lobe 805 will extend outwardly
from the outer surface of the conductor tubing 815 (as illustrated
in FIG. 8A), thereby causing the apex of the lobe 805 to engage the
side of the cardiac vessel and fixedly secure the lead 110
therein.
[0061] The particular embodiments disclosed above are illustrative
only, as the invention may be modified and practiced in different
but equivalent manners apparent to those skilled in the art having
the benefit of the teachings herein. Furthermore, no limitations
are intended to the details of construction or design herein shown,
other than as described in the claims below. It is therefore
evident that the particular embodiments disclosed above may be
altered or modified and all such variations are considered within
the scope and spirit of the invention. Accordingly, the protection
sought herein is as set forth in the claims below.
* * * * *