U.S. patent number 3,844,292 [Application Number 05/261,156] was granted by the patent office on 1974-10-29 for intravascular lead assembly.
This patent grant is currently assigned to Medtronic, Inc.. Invention is credited to Lee Robin Bolduc.
United States Patent |
3,844,292 |
Bolduc |
October 29, 1974 |
INTRAVASCULAR LEAD ASSEMBLY
Abstract
A body-implantable, intravascular lead assembly which is adapted
to be connected to a source of electrical energy at its proximal
end. At the distal end of the lead is affixed an electrically
conductive barb. Means are provided for inserting the lead in and
guiding it through a body vessel to a desired location inside the
body. Further means are provided for lodging and permanently
securing the barb to body tissue at the desired location. Part of
the assembly is withdrawn from the vessel after the barb is lodged
and secured in the tissue. The lead and a portion of the barb are
sealed from body fluids and tissue by a material substantially
inert to body fluids and tissue.
Inventors: |
Bolduc; Lee Robin (Minneapolis,
MN) |
Assignee: |
Medtronic, Inc. (Minneapolis,
MN)
|
Family
ID: |
22992147 |
Appl.
No.: |
05/261,156 |
Filed: |
June 9, 1972 |
Current U.S.
Class: |
607/126 |
Current CPC
Class: |
A61N
1/056 (20130101); A61N 1/0573 (20130101) |
Current International
Class: |
A61N
1/05 (20060101); A61n 001/04 () |
Field of
Search: |
;128/418,419P,419,404,405,2.6E,2.1E,348,349,214.4,2R,2.1R,DIG.4 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
wende et al., Neue Intrakardiale Schrittmacherelektrode, Deutsche
Medizinische, Wochenschrift, Nr. 40, Oct. 2, 70, 95 Jg., pp.
2026-2028. .
Schaldach, New Pacemaker Electrodes, Transactions: Am. Society for
Artificial Internal Organs, Vol. 17, pp. 29-35, 1971..
|
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Cohen; Lee S.
Attorney, Agent or Firm: Rappaport; Irving S. Sivertson;
Wayne A. Breimayer; Joseph F.
Claims
What is claimed is:
1. A body-implantable, intravascular lead adapted to be connected
at its proximal end to a source of electrical energy and
permanently secured at its distal end through the endothelial
tissue of a living animal body for electrical stimulation thereof
comprising:
electrically conductive lead means for insertion in and guidance
through a body vessel to a desired location and position inside an
organ of a living animal body the lead means having a cross-section
which will fit within a body vessel;
electrode means affixed to the distal end of said lead means and
adapted to supply electrical impulses to tissue at a desired
location inside the living animal body, said electrode means
including a tissue piercing portion and further including separate
tissue engaging means for allowing said electrode means to be
firmly lodged in and permanently secured through the endothelial
tissue at the desired location; and
material means substantially inert to body fluids and tissue
encasing said lead means and a portion of said electrode means for
sealing them from living animal body fluids and tissue.
2. The lead of claim 1 wherein the means for allowing the electrode
means to be firmly lodged in and permanently secured through
endothelial tissue comprises means for allowing the electrode means
to be firmly lodged in and permanently secured through endocardial
tissue.
3. A body-implantable, intravascular lead assembly for use in
conjunction with an electromedical device, said lead assembly
comprising:
electrically conductive lead means of a cross-section which will
fit within a body vessel having electrode means affixed to its
distal end and adapted to be electrically connected at its proximal
end to a source of electrical power, said electrode means including
a tissue piercing portion and further including separate tissue
engaging means for allowing said electrode means to be firmly
lodged in and permanently secured through the endothelial tissue of
selected organs of living animal bodies;
means for inserting and guiding said lead means in and through a
body vessel to a desired location and position inside the living
animal body organ;
means for allowing said electrode to be moved a predetermined
distance for firmly lodging and permanently securing said electrode
through the endothelial tissue of the selected organ at the desired
location; and
means substantially inert to body fluids and tissues for encasing
and sealing all of the lead means for the living animal body fluids
and tissue except the distal end of the electrode means.
4. A lead assembly as set forth in claim 3 wherein said electrode
means includes an electrically conductive barb means for insertion
into the tissue.
5. A lead assembly according to claim 4 wherein said insertion and
guide means encases the lead means, said insertion and guide means
comprises two separate concentric tubes fitted one within the
other, the inner tube being connected to a means adapted for moving
it within the outer tube.
6. A lead assembly according to claim 5 wherein said tubes are
substantially cylindrical and the lead means is constructed such
that it has a substantially cylindrical sleeve means having a
cross-sectional diameter greater than the cross-sectional diameter
of the inner tube but less than the cross-sectional diameter of the
outer tube, said sleeve means being positionable within the outer
tube and into abuttment with the distal end of the inner tube so as
to provide movement of the lead means when the inner tube is moved
within the outer tube.
7. A lead assembly as set forth in claim 6 wherein said sleeve
means has at least one ridge formed on the outer surface thereof
the diameter of said ridge being substantially equal to the inside
diameter of said outer tube and forming a seal with the inside wall
of said outer tube to prevent the back flow of body fluids into
said tubes when said sleeve is within said outer tube.
8. A lead assembly as set forth in claim 6 wherein said means for
lodging and securing includes plunger means connected to said inner
tube, said plunger means being adapted to forceably move the inner
tube and lead means a predetermined distance so that the electrode
means of said lead means moves from a position within the outer
tube to a position outside the outer tube, said plunger forceable
movement being used to firmly lodge and permanently secure the
electrode means through the endothelial tissue of the selected body
organ.
9. A lead assembly as set forth in claim 8 wherein said plunger
means includes engageable first locking means which when in locked
position insures that the barb cannot be inadvertently moved from
its position within the outer tube, engageable second locking means
which when locked prevents the plunger means from moving the barb
further from the outer tube than a position in which it just
protrudes from the outer tube, and means for preventing the plunger
means from moving the barb more than a predetermined distance when
lodging and securing the barb thereby preventing overly deep and
injurious barb lodgings.
10. A lead assembly as set forth in claim 3 wherein said insertion
and guide means encases the lead means, said insertion and guide
means being constructed and adapted to impart sufficient rigidity
to facilitate placement of the lead means.
11. The lead assembly of claim 3 wherein the means for firmly
lodging and permanently securing the electrode means through the
endothelial tissue of a selected body organ comprises means for
firmly lodging and permanently securing the electrode through
endocardial tissue.
12. A device for inserting a body-implantable intravascular lead
with an electrode at one end thereof into a body vessel and for
guiding said lead into a desired location and position within a
selected organ of the body, said electrode including a tissue
piercing portion and further including separate tissue engaging
means for allowing said electrode to be firmly lodged in and
permanently secured through endothelial tissue at said selected
body organ, said device comprising:
means surrounding said lead means for inserting and guiding said
lead into and through a body vessel to a desired location and
position inside the selected body organ;
locking means for preventing movement of said electrode beyond a
position where it just protrudes from said inserting and guiding
means; and
plunger means for allowing said electrode to be moved a distance,
greater than said locking means for firmly lodging and permanently
securing said electrode through the endothelial tissue of the
selected organ at the desired location.
13. A device as set forth in claim 12 wherein said insertion and
guide means comprises inner and outer concentric, flexible tubes,
said inner and outer tubes encasing a substantial portion of said
lead, said outer tube being constructed and adapted to encase said
electrode.
14. A device as set forth in claim 13 wherein said plunger means is
operatively connected to said inner tube for allowing said inner
tube and lead to move a predetermined distance so that the
electrode moves from its position within said outer tube so as to
be lodged in and permanently secured to said body tissue.
15. A device as set forth in claim 14 further including additional
locking means for insuring that said electrode cannot be
inadvertently lodged in and secured to body tissue; and said
plunger means including means for allowing said electrode to move
only a predetermined distance from said outer tube when lodging and
securing the electrode in the tissue so as to prevent injury to the
tissue.
16. The device of claim 12 wherein the means for allowing the
electrode to be moved a predetermined distance for firmly lodging
and permanently securing the electrode through endothelial tissue
comprises means for allowing the electrode to be moved a
predetermined distance for firmly lodging and permanently securing
the electrode through endocardial tissue.
17. A body-implantable, intravascular lead assembly for use in
conjunction with an electro-medical device, said lead assembly
comprising:
electrically conductive lead means of a cross-section which will
fit within a body vessel having electrode means affixed to its
distal end and adapted to be electrically connected at its proximal
end to a source of electrical power, said electrode means including
a tissue piercing portion and further including separate tissue
engaging means for allowing said electrode means to be firmly
lodged in and permanently secured through the endothelial tissue of
selected organs of living animal bodies;
means for inserting and guiding said lead means in and through a
body vessel to a desired location and position inside the living
animal body organ;
means for allowing said electrode to be moved a predetermined
distance for firmly lodging and permanently securing said electrode
through the endothelial tissue of the selected organ at the desired
location;
means for allowing a threshold measurement with said electrode
means while preventing a firm lodging and permanent securement of
said electrode means during said threshold measurement; and
means substantially inert to body fluids and tissues for encasing
and sealing all of the lead means from living animal body fluids
and tissue except the distal end of the electrode means.
Description
BACKGROUND OF THE INVENTION
There are generally two types of body-implantable leads--one which
requires surgery to expose that portion of the body to which the
electrode is to be affixed and the other which is inserted in and
guided to the desired location through a body vessel. In the
cardiovascular field, in particular, there are myocardial and
endocardial type leads. Use of a standard myocardial lead generally
provides an excellent electrical contact but requires a thoracotomy
in order to affix the electrodes in the outer wall of the heart.
This type of surgery is quite strenuous on the patient,
particularly an elderly one. Use of a standard endocardial lead
does not involve serious surgery since the lead is inserted in and
guided through a selected vein. However, endocardial leads
currently in use are difficult to place and to maintain in proper
position and do not insure the best electrical contact since the
electrode merely rests against the inner wall of the heart at the
apex of the right ventricle. As a result, the electrodes of such
prior art leads tend to become dislodged from their proper
position, often resulting in loss of heart capture and thus loss of
stimulation of the patient's heart. Also, since the electrodes of
an endocardial lead are not secured in the cardiac tissue, the lead
tends to move with each contraction of the heart muscle, thereby
forming an undesirable callous or fibrotic growth on the inner wall
of the right ventricle. Another problem is that with the
contraction of the heart, the tip or distal electrode may
occasionally puncture the heart wall, resulting in serious injury
to the heart and a loss of heart capture.
The body-implantable lead of the present invention combines all the
advantages of both the myocardial and endocardial leads with none
of the attendant disadvantages of each of these leads as currently
found in the prior art. One of the features of the present
invention is the provision of a body-implantable intravascular lead
which can be lodged in and permanently secured to the body tissue
which it is desired to stimulate. Another feature of the present
invention is an extremely thin, durable, very flexible lead with
excellent electrical and mechanical properties. An advantage of the
present invention is the fact that the electrode is lodged in and
permanently secured to the tissue so that puncturing of the
surrounding tissue and formation of a callous or fibrotic growth
cannot occur. Still another feature of the present invention is the
provision of a very simple, easily operable means for inserting the
lead into and guiding it through a body vessel to the desired
location. An advantage is realized from the fact that the insertion
and guidance means imparts sufficient rigidity to the lead to
facilitate its placement, thereby eliminating the need for a
stylette and thus allowing the lead to be made thinner and more
flexible than would otherwise be possible. Yet another feature is
the means for lodging and permanently securing the electrode to the
selected body tissue once the lead is in proper position. An
advantage is realized from the fact that the insertion and guiding
means and the lodging and securing means may be made as an
integral, disposable unit which is very simple to manufacture, and
extremely easy to operate. Once the electrode is secured in the
tissue at the desired location, this unit is easily removed and can
be disposed.
SUMMARY OF THE INVENTION
The above features and advantages of the present invention, as well
as others, are accomplished by providing a body-implantable,
intravascular lead comprising electrically conductive lead means
adapted to be connected at one end to a source of electrical energy
and electrode means affixed to the opposite end of the lead means
and adapted to be firmly lodged in and permanently secured to
tissue inside the body at a desired location. The lead means and
the portion of the electrode means affixed to the lead means are
sealed from living animal body fluids and tissue by a material
substantially inert to body fluids and tissue. Further means are
provided for permitting the lead means and electrode means to be
inserted into and guided through a body vessel to a desired
location and position inside the body. Means are also provided for
permitting the electrode means to be firmly lodged in and
permanently secured to body tissue at the desired location.
Other features, advantages and objects of the present invention
will hereinafter become more fully apparent from the following
description of the drawings, which illustrate a preferred
embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a view of the body-implantable, intravascular lead of
the present invention;
FIG. 2 shows a view of the device used for positioning the lead of
FIG. 1 inside the body;
FIG. 3 shows the lead assembly comprising the lead of FIG. 1 and
the device of FIG. 2 with the lead in the position for insertion in
and guidance through a body vessel to a desired location and
position inside the body;
FIG. 4 shows the lead assembly of FIG. 3 in the position for taking
threshold measurements with the barb of the lead of FIG. 1 just
barely extending beyond the device of FIG. 2;
FIG. 5 shows the lead assembly of FIG. 3 in another position for
the lodging and securing of the electrode of the lead into the body
tissue at the desired location inside the body; and
FIG. 6 shows the lead assembly of FIGS. 3 and 4 with the electrode
of the lead lodged in and permanently secured in the tissue forming
the apex of the right ventricle of a heart.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a lead 10 having an electrical conductor 12 which may,
for example, be of a configuration and construction as the lead
described in U.S. Pat. No. 3,572,344. Affixed to the distal end 14
of conductor 12 is an electrically conductive electrode 16 having a
sharply-pointed electrically conductive barb 18 formed on the end
thereof, both of which may be metallic. Electrode 16 and barb 18
are made of a metal which is substantially inert to body fluids and
tissue, such as platinum or a platinum-iridium alloy. Conductor 12
has a covering 20 which is made of a material substantially inert
to body fluids and tissue such as, for example, silicone rubber.
Surrounding the distal end 14 of conductor 12 and a portion of
electrode 16 is a substantially cylindrical sleeve 22 having three
spaced ridges 24 formed integrally therewith along its length.
Sleeve 22 and ridges 24 are formed as an integral sleeve and may be
made of a material substantially inert to body fluids and tissue,
such as silicone rubber. Proximal end 28 of conductor 12 may be
fitted with a connector pin (not shown) or in any other manner
adapted for connection to a source of electrical energy such as a
pulse generator.
FIG. 2 shows a cross sectional view of a device 30 which may be
used for positioning the lead 10 of FIG. 1 at the desired location
within the body as will be described hereinafter. Device 30 has a
pair of concentric, substantially cylindrical hollow tubes 32 and
34. Tubes 32 and 34 are made of a pliant material, such as, for
example, teflon. Outer tube 32 is maintained in a fixed position by
a substantially cylindrical, hollow sleeve 38 having a flat plate
40 formed integrally therewith. Sleeve 38 and plate 40 may be made
of a machineable polymer such as Delrin or Nylon. Inner tube 34 is
axially movable within outer tube 32 and sleeve 38. Projecting
through an opening in plate 40 is a plunger 42, also made of a
machineable polymer such as Delrin or Nylon. Plunger 42 has an
opening 44 passing therethrough. Plunger 42 has an end 46 to which
is affixed inner tube 34. Tube 34 and opening 44 define a
passageway in which lead 10 is placed as will be described later.
As plunger 42 is pushed toward plate 40, when the appropriate
locking mechanisms are unlocked, tube 34 moves axially within and
toward the distal end 48 of tube 32.
Device 30 has a first locking mechanism 49. With reference to FIG.
4, locking mechanism 49 comprises a slide 50 having a pin 52
projecting from one end thereof. Sleeve 38 and plunger 42 have
aligning openings in one side thereof through which pin 52 passes
for providing this first locking mechanism. With pin 52 in the
aligned openings, plunger 42 cannot be moved in either direction. A
screw 53 shown in FIG. 2 passes through an elongated opening
through plate 40 and into slide 50 and allows slide 50 to move so
that pin 52 may be engaged with, or disengaged from, the openings
in the sides of sleeve 38 and plunger 42.
Device 30 has a second locking mechanism 54 comprising a second
slide 56 having a lip 58 which may be grasped for engaging and
disengaging an edge 60 of slide 56 with the opposing face of
plunger 42. Slide 56 has a pair of legs 62 between which plunger 42
is located. Slide 56 has an elongated opening. A screw 64 passes
through plate 40 and slide 56 and together with legs 62 allows
slide 56 to have edge 60 engage with and disengage from a groove 66
located in the opposing face of plunger 42. Plunger 42 also has a
pair of shoulders 67 on opposite sides thereof which are designed
to engage legs 62 when locking mechanism 54 is unlocked and plunger
42 is fully depressed.
The operative relationship between device 30 and lead 10 will now
be described in conjunction with FIGS. 3-5. Lead assembly 70 will
be described in the application of using lead 10 as a lead
positioned intravenously into the heart for use as a cardiac
pacemaker lead. When the lead assembly 70 shown in FIG. 3 is
removed from its sterile package, lead 10 is positioned in the
opening defined by tube 34 and opening 44 in plunger 42. Pin 52 of
slide 50 is positioned in the aligned openings in sleeve 38 and
plunger 42 and slide 56 is in the locked position whereby edge 60
abuts against groove 66 in the opposing face of plunger 42. With
locking mechanisms 49 and 54 in their locked positions as shown in
FIG. 3, electrode 16 and barb 18 are located well inside outer tube
32 with the sleeve 22 abutting against the distal end of tube 34.
Ridges 24 of sleeve 22 engage the inner wall of tube 32 thereby
forming a seal to prevent the back-up of blood into tubes 32 and 34
when device 30 with lead 10 carried thereby is inserted into a body
vessel. With the locking mechanisms 49 and 54 in their locked
positions, as shown in FIG. 3, the distal end 48 of tube 32 is
inserted, for example, into the right jugular vein. Device 30
serves as a means for inserting lead 10 into the vein and guiding
it to the desired position in the heart. When the tube 32 is
believed to be in the proper position in the heart, locking
mechanism 49 is unlocked as shown in FIG. 4 by pulling slide 50 so
that pin 52 is disengaged from the aligned openings in sleeve 38
and plunger 42. Plunger 42 may then be depressed to move inner tube
34 and lead 10 to a position, shown in FIG. 4, where the edge
defined by groove 66 in plunger 42 is stopped by edge 60 of locking
mechanism 54. In this position barb 18 just barely extends beyond
the end 48 of tube 32 so that the necessary threshold measurements
may be taken. The threshold measurements are used to determine
whether the electrode position in relation to the heart tissue is
adequate or not. Good electrode positioning is important, as only
with good positioning can the patient's heart be maintained in
capture at low voltages. When these measurements have been
completed and a satisfactory electrode position found, locking
mechanism 54 is unlocked, as shown in FIG. 5, by moving slide 56 in
a direction away from plunger 42. Movement of slide 56 disengages
edge 60 of slide 56 from plunger 42. This disengagement allows
plunger 42 to be further depressed until shoulders 67 of plunger 42
engage legs 62 of slide 56, thereby moving electrode 16 a
predetermined distance out of tube 32 and driving barb 18 a
predetermined distance into the tissue of the heart. These
predetermined distances are such that barb 18 is driven
sufficiently into myocardial tissue to be permanently secured
therein but without puncturing through the heart's wall. The total
distance through which barb 18 moves is determined by the distance
X from shoulders 67 to the surface of slide 56 when both locking
mechanisms 49 and 54 are in their locked positions as shown in FIG.
3. Device 30 may then be completely withdrawn from the vein by
pulling device 30 past lead 10, leaving barb 18 lodged in and
permanently secured to heart tissue.
FIG. 5 shows plunger 42 in its fully depressed position with
shoulders 67 abutting legs 62 and with electrode 16 extended beyond
end 48 of tube 32. FIG. 6 shows barb 18 lodged in and permanently
secured in heart tissue and with device 30 partially withdrawn.
After device 30 is fully withdrawn from the vein, the proximal end
28 of lead 10 is ready to be connected to the pulse generator for
applying stimulating pulses through lead 10 and electrode 16 to the
heart.
A single lead 10 would be used in a monopolar pacing system. Use of
a pair of leads 10 would permit use of a bipolar system. It should
be understood that although the use of lead 10 and device 30
together in lead assembly 70 have been described for use in a
cardiac pacing system, lead assembly 70 could be used in other
types of body stimulating applications.
It should be understood, of course, that the foregoing disclosure
relates to only a preferred embodiment of the present invention and
that numerous modifications may be made therein without departing
from the spirit and scope of the invention as set forth in the
appended claims.
* * * * *