U.S. patent number 3,875,947 [Application Number 05/443,802] was granted by the patent office on 1975-04-08 for device for screwing body tissue electrode into body tissue.
Invention is credited to James L. Jula, Dennis Zeidler.
United States Patent |
3,875,947 |
Jula , et al. |
April 8, 1975 |
DEVICE FOR SCREWING BODY TISSUE ELECTRODE INTO BODY TISSUE
Abstract
A primary and auxiliary tool employed in implanting an
electrical lead in body tissue, the primary tool having means
associated therewith for holding the lead during implantation so as
to avoid imparting torque to the lead, such means including a
slotted end, a longitudinally extending groove and a longitudinally
extending bore which communicates with the groove and the slotted
end. The auxiliary tool which includes a body portion moveable in
the bore, a ridge portion moveable in the groove, and a terminal
portion moveable in the slotted end, serves to remove the lead from
the primary tool after implantation of the electrode.
Inventors: |
Jula; James L. (White Bear
Lake, MN), Zeidler; Dennis (Anoka, MN) |
Family
ID: |
23762264 |
Appl.
No.: |
05/443,802 |
Filed: |
February 19, 1974 |
Current U.S.
Class: |
607/131 |
Current CPC
Class: |
A61N
1/0587 (20130101) |
Current International
Class: |
A61N
1/05 (20060101); A61n 001/04 () |
Field of
Search: |
;128/418,419P,404,DIG.4,2.6E,2.1E |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Cohen; Lee S.
Attorney, Agent or Firm: Kirn, Jr.; Walter N.
Claims
What is claimed is:
1. A device for use in screwing the conductive uninsulated distal
end portion of a body implantable electrode assembly into body
tissue, said assembly being of the type including a flexible
insulated electrical conductor having a proximal end thereof
adaptable for connection to a power supply, said device comprising:
(1) first means for firmly holding a portion of said electrode
assembly near said uninsulated distal end portion thereof, (2)
second means adapted to contact an insulated portion of said
insulated conductor for releasably holding said conductor to
facilitate the screwing of said distal end portion into body tissue
and for preventing the transmission of torque to said proximal end
of said conductor means when said distal end portion is being
screwed into body tissue, and (3) third means communicating with
said first and second means for allowing said electrode and said
conductor to be released from said first and second means by means
locatable in said third means.
2. The device of claim 1 wherein said third means is an
aperture.
3. The device of claim 1 wherein said device is substantially
cylindrically shaped.
4. The device of claim 1 wherein said second means comprises a
groove formed in the outer surface of said device and said third
means comprises an aperture.
5. The device of claim 4 wherein said groove extends substantially
parallel to the longitudinal axis of said device, and said aperture
communicates with said groove along substantially the entire length
of said groove.
6. The device of claim 1 wherein said third means is an
axially-extending aperture extending from one end of said device to
the other end.
7. The device of claim 1 wherein said first means comprises a first
portion located at one end of said device defining an external
opening, and a second portion located interior of and in
communication with said first portion, said second portion defining
an internal opening, said internal opening being wider than said
external opening.
8. The device of claim 7 wherein said third means communicates with
said second portion of said first means whereby said distal end
portion can be removed from said first means by means inserted into
said second portion via said third means.
Description
BACKGROUND OF THE INVENTION
This invention relates to the field of medical electronics and
particularly to an improved device for handling electrical leads
having implantable body tissue electrodes.
U.S. Pat. No. 3,737,579 discloses a device or tool for holding an
electrical lead during body implantation in such a manner that by
rotating the tool the helix-shaped electrode can be screwed into
place without imparting torque to the lead along its entire length.
The lead or electrode assembly includes three functionally distinct
sections: (1) an implantable, conductive helix-shaped electrode
affixed to an insulated boot, (2) a flexible, insulatingly covered
conductor, and (3) a plug or connector for connection to a power
source. The device or tool for holding this lead disclosed in the
above-mentioned patent includes three elements which serve to hold
the lead during implantation--a slotted end, a longitudinally
extending groove, and a bore extending the length of the tool, and
parallel to the groove. The slotted end has straight, uniplanar
sides dimensioned to accomodate the boot with enough compression to
retain the boot in the slot during the implantation procedure yet
permitting removal of the boot from the slot without disturbing the
implanted helix. While the boot member has proved satisfactory,
some problems have been encountered in retaining the boot in the
slot if the boot and/or the slot is wet, especially prior to
initially positioning the boot in the slot.
The longitudinally extending groove of the former device
accomodates the flexible, insulatingly covered conductor during
implantation while the bore receives the connector. Once the
helix-shaped electrode is implanted in the body tissue, the lead is
disengaged from the tool in three steps; first, removal of the
connector from the bore; second removal of the boot member from the
slotted end; and third, removal of the flexible conductor from the
groove. The second step is preferably accomplished by an auxiliary
tool shaped like a knitting needle which is inserted through the
bore until the end of the needle-shaped tool pushes the electrode
boot out of the slot. This operation does not, however,
simultaneously remove the flexible, insulatingly covered conductor
from the groove. Depending upon the tightness of the grip between
the outer surface of the flexible conductor and the groove, freeing
of the flexible conductor can be a cumbersome task in the surgical
environment.
In the present invention, there is provided a device for use in
screwing the conductive uninsulated distal end portion of a body
implantable electrode assembly into body tissue, said assembly
being of the type including a flexible insulated electrical
conductor having a proximal end thereof adaptable for connection to
a power supply, said device comprising: (1) first means for firmly
holding a portion of said electrode assembly near said uninsulated
distal end portion thereof, (2) second means adapted to contact an
insulated portion of said insulated conductor for releasably
holding said conductor to facilitate the screwing of said distal
end portion into body tissue and for preventing the transmission of
torque to said proximal end of said conductor means when said
distal end portion is being screwed into body tissue, and (3) third
means communicating with said first and second means whereby said
electrode is releasable from said first and second means by means
locatable in said third means.
A second or auxiliary device for use in combination with the
above-defined primary device is also provided, such auxiliary
device including a first portion moveable in the third means of the
primary device, a second portion associated with the first portion
and moveable in the second means of the primary device, and a third
portion moveable into the first means of the primary device whereby
movement of the auxiliary device into operative position with
respect to the primary device removes the implantable electrode
from the primary device. As will be seen hereinafter, this
auxiliary device permits the boot-shaped distal end of the lead to
be removed from the slotted end of the primary device in the same
operation as the flexible, insulatingly covered conductor from the
groove of the primary device.
Drawings are provided wherein:
FIG. 1 is a perspective view of the primary device of this
invention holding an implantable lead;
FIG. 2 is a perspective view of the auxiliary device of this
invention;
FIG. 3 is a transverse sectional view of the primary and auxiliary
devices in an operative position;
FIG. 4 is an enlarged top view of the working end of the primary
device; and
FIG. 5 is a sectional view taken along lines 5--5 of FIG. 4.
In FIG. 1 an implantable lead 1 is held by device 3. Lead 1, which
is essentially the same as lead 10 depicted in FIG. 1 of U.S. Pat.
No. 3,737,579, includes a flexible conductor 7 of wrapped platinum
wire or other suitable conducting material adaptable to the
internal environment of a human or animal body.
Affixed to the proximal end of conductor 7 is an electrical
connector 9 having a tip or extension 11 which may be connected to
a suitable implantable or external power supply. Affixed to and
serving as the distal end portion of conductor 7 is a rigid helical
electrode 13 (see FIG. 3) having several convolutions. Helical
electrode 13 is a rigid coil which may, for example, be made of
platinum/irridium and terminates in a sharply pointed end 15.
Electrode 13 serves as the distal end portion of conductor 7 which
may be screwed into body tissue as will be explained later.
Electrode 13 and conductor 7 are electrically joined together by
conductive epoxy (not shown) substantially orthogonally with
respect to one another and this electrical junction is contained in
a rubber boot 17.
Conductor 7, connector 9 and boot 17 are covered with a relatively
transparent, flexible, insulating covering being relatively inert
with respect to the body, which, for example, may be a silicone
rubber casing 19. The portion of casing 19 surrounding boot 17
forms a raised portion or projection 21. The distal portion of
casing 19 is terminated and shaped as a circular disc 20 through
which helical electrode 13 projects. Helical electrode 13 projects
through the disc 20 at substantially a right angle to conductor 7.
Affixed to the under surface of the disc is a circular sheet of
netting 23, which may, for example, be made of Dacron, a trademark
of E. I. DuPont DeNemours and Company for a type of polyester
fiber. Netting 23 enhances fibrotic growth, further insuring a
secure connection of the electrode to the tissue.
The device 3 is adapted to hold lead 1 at three places; the boot
17, casing 19, and connector 9. Device 3 comprises a substantially
cylindrically-shaped body 25 having a longitudinal axis 27 and end
surfaces 29 and 31. Device 3 may be made, for example, of a hard
plastic material such as Delrin, a trademark of the E. I. DuPont
DeNemours and Company for acetal resins. Preferably device 3 should
be made of an autoclavable material. Formed in end surface 29 is a
slot 33. Slot 33 includes a frontal opening 35 leading to a cavity
37. The width of cavity 37 is greater than the width of frontal
opening 35. The widths of frontal opening 35 and cavity 37 are
selected such that boot 17 must be laterally compressed to a slight
degree in order to pass through frontal opening 35. Once at least a
portion of boot 17 is past the shoulders 38, that portion resumes
its original shape. To remove boot 17 from slot 33 requires
recompressing such portion in order to gain withdrawal from frontal
opening 35. The shape of slot 33 and boot 17 is designed such that
the force required to achieve the requisite compressive state is
greater than the forces that might be encountered in the
implantation procedure but insufficient to disturb the implanted
electrode 13 as the boot 17 and slotted end 29 are being separated.
Formed in the outer surface of device 3, lying in a plane
substantially parallel to axis 27, and extending from end surface
31 for substantially the entire length of device 3, is a groove 39.
Groove 39, which is substantially aligned with slot 33, is adapted
to receive and securely engage at least a portion of the length of
casing 19. End surface 31 includes a slot 40 which communicates
with a central bore 41. Central bore 41 includes a first section 42
which extends slightly beyond groove 39 and a second section 44 of
reduced diameter which is concentric with section 42. Section 42 of
bore 41 is adapted to receive at least a portion of the proximal
end of lead 1 including connector 9 and tip 11. Bore 41
communicates with groove 39 the entire length of groove 39. At the
approach to end 29, groove 39 provides a terminal portion 46 which
slants downward towards end 29 until it merges with bore 41. As
will be seen hereinafter this terminal portion of groove 39 is
shaped to accomodate the terminal portion of an auxiliary tool. The
cross-sectional dimension of groove 39 is preferably less than the
cross-sectional dimension of section 42 of bore 41. Groove 39 is
wide enough to receive and hold casing 19, yet preferably not so
wide that casing 19 is able to drop into section 42 of bore 41.
In FIG. 2 there is shown an auxiliary tool 43 for use in
combination with the device 3. Tool 43 includes a substantially
cylindrical body portion 45, a terminal portion 47, and a ridge
portion 49. Body portion 45 is designed to slide freely in bore 41
of device 3. As body portion 45 advances in bore 41 from end 31 to
end 29, ridge portion 49 simultaneously advances in groove 39.
Ridge portion 49 should be of such a size and shape that it is
freely slidable in groove 39 and will push or wedge the casing 19
out of groove 39 as it slides along. Ridge portion 49 is preferably
relatively thin, with flat, parallel side walls. The leading edge
51 of ridge portion 49 preferably slants downwardly to meet body
portion 45 at the terminal portion 47. Terminal portion 47 is
tapered to a centered point 53. This allows the casing 19 to be
pushed forward and upward out of groove 39 rather than just
forward. Terminal portion 47 is generally conically-shaped with the
cone apex (end 53) being sufficiently blunt so that it will push
rather than penetrate boot 17 in slot 33. The terminal portion 47
is preferably of such a size and shape that the length thereof
which will extend from the end of section 44 of bore 41 is
approximately equal to or slightly longer than the depth of cavity
37. Auxiliary tool 43 may be constructed of the same material as
device 3.
At the opposing end of terminal portion 47, tool 43 contains an
aperture 55 including a circular opening 57 and a slot 59
communicating therewith leading to the outersurface of body portion
45. Aperture 55 is provided to accomodate tip 11 of lead 1. As will
be explained hereinafter, after implanting the helical electrode 13
in tissue and removing lead 1 from device 3, the dangling tip 11
can be inserted into aperture 55 and tool 43 used as a tunneling
device to tunnel through subcutaneous tissue to bring lead 1 to a
proper position for connection at tip 11 to a suitable power
supply.
FIG. 3 depicts the primary device 3 of FIG. 1 gripping the lead 1
at the slotted end 33 and partially along groove 39. Tool 43 has
been inserted in bore 41 and advanced partially therealong towards
slot 33. That segment of casing 19 previously located in the
section of groove 39 which has been traversed by ridge portion 49
has been displaced from groove 39 whereas the remainder of casing
19 as well as boot 17 await displacement as tool 43 advances.
In explanation of the manner of using the present invention, the
first step is to secure the lead 1 to the device 3 as shown in FIG.
1. The raised portion of boot 17 is fitted into frontal opening 35
with compression and then at least a portion of boot 17 pushed into
cavity 37 to provide a secure hold of boot 17.
A small loop is left in the portion of casing 19 immediately
proximal to boot 17 and then casing 19 is worked into groove 39 so
as to be securely held in the groove against movement. Then
connector 9 and tip 11 are then doubled back for insertion into
bore 41 as far as they will go. In this position the electrode 13
is positioned substantially parallel to longitudinal axis 27 of
device 3 and the assembly is now ready for the electrode to be
screwed into body tissue.
Pointed end 15 is placed against the tissue or organ and device 3
is rotated as indicated by the curved arrow. The diameter of the
wound is confined to the diameter of the wire of which helical
electrode 13 is formed. As device 3 is rotated, helical electrode
13 is firmly screwed into the tissue or organ until netting 23
firmly contacts the outer surface of the organ. Netting 23 helps to
provide a more secure and permanent placement of electrode 13 in
the tissues in that the netting promotes more rapid fibrosis in and
around the netting, as well as around the disc 20 and raised
portion 21 of casing 19.
When electrode 13 is firmly screwed into the tissue and netting 23
firmly seated against the outer surface of the tissue or organ, the
connector end of lead 1 is removed from bore 41. Then, the
auxiliary tool 43 is utilized as described above to progressively
remove the portion of casing 19 lying in groove 39, and then the
boot 17 held in slot 33, thereby freeing lead 1 from device 3. With
the use of the implantation procedure described, since boot 17 and
a substantial portion of casing 19 are firmly secured during the
rotation of device 3, no torque is transmitted to lead 1 and
consequently to conductor 7. In addition, before, during, and after
the insertion procedure, device 3 in no way contacts the helical
convolutions of electrode 13, permitting a very positive action in
screwing electrode 13 into the tissue at substantially a 90.degree.
angle.
After implantation, tip 11 may be inserted in aperture 55 of tool
43 and tool 43 then passed, terminal portion 47 end first, through
subcutaneous tissue until the site is reached where tip 11 is to be
connected to a power supply under the skin. The tip 11 is then
removed from aperture 55 and the electrical connection made. While
tool 43 may be employed for this purpose it is also possible to
employ a tool of the same design and shape as tool 43 except that
ridge 49 is absent, making the body substantially cylindrical in
shape with the other elements of tool 43 retained.
* * * * *