U.S. patent application number 12/035194 was filed with the patent office on 2008-06-26 for connection structures for extra-vascular electrode lead body.
This patent application is currently assigned to CVRx, Inc.. Invention is credited to Stephen L. Bolea, Aaron Hjelle, David W. Mayer, Martin A. Rossing.
Application Number | 20080154349 12/035194 |
Document ID | / |
Family ID | 35786627 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080154349 |
Kind Code |
A1 |
Rossing; Martin A. ; et
al. |
June 26, 2008 |
CONNECTION STRUCTURES FOR EXTRA-VASCULAR ELECTRODE LEAD BODY
Abstract
Connection structures on an extra-vascular electrode lead body
improve strain relief and strengthen the transition region where
electrical conductors carried by the lead body are joined to
individual electrodes at the distal end of the lead. The electrodes
include structure or mechanisms for externally securing the
electrode assembly to a body part. A first connection structure is
located on the lead body proximal the electrodes to anchor the lead
body to a first anchor location in the body that generally moves in
concert with the body part. A second connection structure is
located on the lead body proximal to the first connection structure
to anchor the lead body to a second anchor location that is at
least partially independent of movement of the body part. The first
and second anchor location are offset by a distance that is less
than a distance between the first and second connection structures
to provide strain relief for the electrodes.
Inventors: |
Rossing; Martin A.; (Coon
Rapids, MN) ; Bolea; Stephen L.; (Watertown, MN)
; Mayer; David W.; (Bloomington, MN) ; Hjelle;
Aaron; (Champlin, MN) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER, EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
CVRx, Inc.
Minneapolis
MN
|
Family ID: |
35786627 |
Appl. No.: |
12/035194 |
Filed: |
February 21, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11168753 |
Jun 27, 2005 |
|
|
|
12035194 |
|
|
|
|
60584915 |
Jun 30, 2004 |
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Current U.S.
Class: |
607/116 |
Current CPC
Class: |
A61N 1/3752 20130101;
A61N 1/05 20130101; H01R 13/5804 20130101; H01R 4/4863 20130101;
H01R 4/14 20130101; A61N 1/0558 20130101; H01R 2201/12 20130101;
H01R 13/5224 20130101; A61N 1/0551 20130101 |
Class at
Publication: |
607/116 |
International
Class: |
A61N 1/05 20060101
A61N001/05 |
Claims
1. An extra-vascular lead for use with an implantable medical
device, said lead comprising: an elongated flexible lead body
having a proximal end and a distal end and two conductors extending
therebetween; a connector disposed on the proximal end of the lead
body and adapted to electrically and mechanically attach to the
implantable medical device; at least three electrodes electrically
connected to the two conductors at the distal end of the leady
body; a proximal connection structure adapted to anchor the lead
body at a proximal location on a patient body structure; and a
distal connection structure adapted to anchor the lead body to a
distal location on the patient body structure; wherein the one
conductor is attached to one electrode and the other conductor is
attached to the other two electrodes, as part of the distal
connection structure.
2. The extra-vascular electrical lead of claim 1, wherein the
proximal and distal connection structures are separated by a
distance of at least 2.5 cm.
3. The extra-vascular electrical lead of claim 1 wherein the distal
and proximal connection structures each comprise suture wings that
extend laterally from the lead body.
4. The extra-vascular electrical lead of claim 1 wherein the lead
body has a flexibility sufficient to permit at least one
overlapping loop of the lead body to be created between the distal
and the proximal anchor locations during implantation of the
electrical lead body.
5. A method comprising: connecting a first conductor to a first
junction housing; connecting a first electrode coil to a first
junction pin; connecting a second electrode coil to a first
junction pin; and inserting the first junction pin into the first
junction housing.
6. The method of claim 5, further comprising wrapping a first wire
of the first electrode coil around the first junction pin.
7. The method of claim 5, further comprising welding a first wire
of the first electrode coil to the first junction pin.
8. The method of claim 5, further comprising wrapping a second wire
of the second electrode coil around the first wire and the first
junction pin.
9. The method of claim 5, further comprising welding a second wire
of the second electrode coil to the first junction pin.
10. The method of claim 5, wherein the first junction housing
applies pressure to the first junction pin.
11. The method of claim 5, wherein inserting the first junction pin
into the first junction housing connects the first electrode coil
and the second electrode coil to the first conductor.
12. The method of claim 5, wherein removing the first junction pin
from the first junction housing disconnects the first and second
electrode coils from the first conductor.
13. The method of claim 5, further comprising: connecting a second
conductor to a second junction housing; connecting a third
electrode coil to a second junction pin; and inserting the second
junction pin into the second junction housing.
14. An electrode assembly for use with an implantable medical
device, the electrode assembly comprising: a first electrode coil
electrically coupled to a first junction pin; a second electrode
coil electrically coupled to both the first junction pin and the
first electrode coil; the first junction pin extending into it
first junction housing; and a first conductor connected to the
first junction housing.
15. The electrode assembly of claim 14, wherein the first electrode
coil comprises a first wire that is wrapped around the first
junction pin at least two times.
16. The electrode-assembly of claim 14, wherein the first coil is
welded to the first junction pin.
17. The electrode assembly of claim 14, further comprising: a third
electrode coil connected to a second junction pin; the second
junction pin extending into a second junction housing; and a second
conductor connected to the second junction housing.
18. The electrode assembly of claim 17, wherein the third electrode
coil comprises a third wire that is wrapped around the second
junction pin at least two times.
19. The electrode assembly of claim 17, wherein the third coil is
welded to the second junction pin.
20. The electrode assembly of claim 17, wherein the first junction
housing applies pressure to the first junction pin.
21. The electrode-assembly of claim 17, wherein the second junction
housing applies pressure to the second junction pin.
22. The electrode assembly of claim 17, wherein removing the first
junction pin from the first junction housing disconnects the first
electrode from the first conductor.
23. The electrode assembly of claim 17, wherein removing the second
junction pin from the second junction housing disconnects the third
electrode from the second conductor.
24. The electrode assembly of claim 14, wherein the first conductor
comprises a first coil.
25. The electrode assembly of claim 24, further comprising a first
insulator disposed around the first coil.
26. The electrode assembly of claim 25, wherein the second
conductor comprises a second coil disposed around the first
insulator and the first coil.
27. The electrode assembly of claim 26, further comprising a second
insulator disposed around the second coil.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 11/168,753 (Attorney Docket No.
021433-001310US), filed Jun. 27, 2005, which claimed the benefit of
Provisional U.S. Patent Application No. 60/584,915 (Attorney Docket
No. 021433-001300US), filed Jun. 30, 2004, the full disclosures of
which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] This invention relates generally to electrode leads for
implantable medical devices. More particularly, the present
invention relates to connection structures for anchoring an
extra-vascular electrode lead body and providing improved strain
relief, as well as providing a more robust region for transitioning
electrical conductors carried by the lead body to individual
electrodes at the distal end of the lead.
[0003] Implantable pulse generator medical devices are well known
in the art, and include medical devices such as pacemakers,
defibrillators and muscle and nerve stimulators. Generally, these
medical electrical devices comprise an implantable pulse generator
unit and an electrical lead or leads connected to one or more
electrodes. The electrode may be placed adjacent to a particular
part of the human body, such as within the myocardial tissue of the
heart, within a vein or proximate any other tissue to be stimulated
and/or sensed. The electrode, which is attached at the distal end
of the lead, is attached to the appropriate location in the human
body, and the proximal end of the lead is connected to a header of
the implantable pulse generator.
[0004] In the case of pacemakers and defibrillators, the vast
majority of electrical leads now used with these implantable
devices are intra-vascular leads, i.e. endocardial leads or
transvenous leads, that are introduced into a vein and then routed
through the vein to the right side of the heart. Once in the heart,
tines or screw-in structures on the distal end of the lead are
generally used to secure the electrodes in position. In the most
cases, a suture sleeve that surrounds the lead body of an
intra-vascular lead is positioned at a location well proximal to
the electrodes where the lead body enters the vein. The suture
sleeve includes structure that permits the suture sleeve, and
hence, the electrical lead to be sutured to the vein. Examples of
various designs for suture sleeves for intra-vascular leads are
shown in U.S. Pat. Nos. 5,129,405, 5,423,763 and 5,603,730. U.S.
Pat. No. 5,376,108 describes a dual suture collar technique for an
intra-vascular lead that utilizes two suture collars tethered to
one another by a flexible retaining member. Other examples of
techniques for securing intra-vascular leads in position are shown
in U.S. Pat. Nos. 4,394,866, 5,682,403 and 5,782,898.
[0005] Extra-vascular electrical leads, i.e., leads that are not
implanted within a vein or artery, are more commonly used with
other forms of implantable tissue stimulators, such as nerve
stimulators or tissue stimulators. In the case of nerve
stimulators, early designs for nerve stimulation electrical leads
secured the electrode around a desired location along a nerve by
positioning the electrode in a flexible insulator cuff that was
then wrapped around the nerve and sewn together. Examples of this
wrapped cuff technique are shown in U.S. Pat. Nos. 3,654,933 and
3,774,618.
[0006] While simple in design, chronically reliable electrical
connections were difficult to attain with these types of prior art
cuffs. In a chronic setting, it was found that many medical
electrical leads with such simple cuff arrangements could
electrically or mechanically damage a nerve. Mechanically induced
damage included thickened epineurium due to accumulation of
connective tissue between the electrode and the nerve, increased
subperineural and endoneural connective tissue, endoneural edema,
demyelinization, axonal degeneration and frank axonal loss. Such
damage may be caused in several ways. First, if the lead and the
electrode that interfaces with the nerve does not move with the
nerve, then abrasion of the nerve may result. Second, the presence
of the lead and the electrode may cause edema or swelling of the
nerve. As the nerve swells, the nerve may be constricted by the
electrode. A compressive force may thereby be induced upon the
nerve. Prior art cuff nerve electrodes also could led to
electrically induced damage. Such damage results in axonal
degeneration as well as nerve edema. While it has been shown that
the type of electrical stimulation, e.g., frequency, waveform, and
amplitude may be a significant factor, the actual electrode design
could also affect the degree of electrically induced damage.
[0007] In recognition of these problems, so-called "self sizing"
nerve cuff electrodes were developed to avoid such damage. Examples
of such self-sizing cuff electrode may be seen in U.S. Pat. Nos.
4,573,481, 4,602,624, 4,920,979, 5,344,438, 5,095,905 and
5,938,596. To date, however, such electrodes have not produced
long-term satisfactory results because they can to be difficult to
install and because they are more difficult to keep secured in a
given location as a result of their self sizing design.
[0008] Another example of a nerve electrode arrangement is shown in
U.S. Pat. No. 4,590,946 which describes an electrode system that
includes two or more electrically conductive elements embedded in a
helically wound substrate made of insulative material. A separate
membrane pouch is needed to insulate the electrode from adjacent
body tissue. This pouch greatly increases the bulk of the electrode
and, thus, increases the potential for mechanically induced neural
trauma. A strain relief for the lead-in conductors is taught by
this patent in the form of a single strap around the conductors
that is screwed or otherwise surgically attached to adjacent body
tissue.
[0009] The lead body of an implantable extra-vascular electrical
lead is made of flexible resilient material to accommodate the
movement of the nerve bundle itself and the movement of the nerve
bundle relative to surrounding tissue. Since the electrode(s) of
the electrical lead is attached to the nerve, any relative movement
between the nerve bundle and the surrounding tissue can impart a
strain on the junction between the lead conductors in the lead body
and the electrode, as well as on the nerve itself. Any mechanical
forces transmitted to the nerve via the lead conductors can cause
damage to the nerve or dislocation of the electrode(s).
[0010] One example of a therapy delivered by an implantable pulse
generator to a nerve stimulation electrical lead is a baroreflex
activation lead and electrode that is positioned at the carotid
sinus for baroreflex activation. An intra-vascular electrical lead
positioned inside the carotid sinus for this therapeutic
application is shown in U.S. Pat. No. 6,522,926. U.S. Publ. Appl.
Nos. 2003/0060857A1 and 2004/0010303A describe extra-vascular
electrical leads wrapped around the exterior of the carotid sinus
in order stimulate the baroreflex activation. While different
electrode structures and arrangements for suture pads to secure
these extra-vascular electrodes are described in these
publications, there is no description or discussion of how to
secure the lead body of such extra-vascular electrical leads.
[0011] Accordingly, there is a need for a system that overcomes the
problems set forth above and contemplates a new and robust
connection structure that minimizes the stress on the lead body
caused by body motion without straining the electrode.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention provides connection structures for
anchoring an extra-vascular electrode lead body that improve strain
relief and strengthen the transition region where electrical
conductors carried by the lead body are joined to individual
electrodes at the distal end of the lead. The extra-vascular
electrical lead has an elongated flexible lead body with a
connector assembly at a proximal end connected to at least one
conductor carried within the lead body that is connected at a
distal end to at least one electrode assembly. The electrode
assembly includes structure or mechanisms for externally securing
the electrode assembly to a body part. A distal connection
structure is located on the lead body proximal the electrode
assembly to anchor the lead body to a distal anchor location in the
body that generally moves in concert with the body part. A proximal
connection structure is located on the lead body proximal to the
distal connection structure to anchor the lead body to a proximal
anchor location in the body that is at least partially independent
of movement of the body part. The distal anchor location and the
proximal anchor location are offset in the body by a distance that
is less than a distance between the distal and proximal connection
structures in order to provide strain relief for the electrode
assembly against movement of the body part.
[0013] In a preferred embodiment, the electrical lead is connected
at a proximal end to a pulse generator implanted in the pectoral
region of the patient. The electrode assembly at the distal end of
the lead is attached to the carotid sinus. The carotid sinus may
move when the patient swallows or has other small movements in the
head. Therefore, it is desirable to relieve strain between the
electrode on the carotid sinus and a distal fixation point
associated with the distal connection structure. This distal
fixation point moves in concert with the carotid sinus to prevent
strain from being applied directly to the carotid sinus. A proximal
fixation point is also provided at the proximal connection
structure. The proximal fixation point provides strain relief for
larger movements of a patient's head or neck. The lead body between
the distal and proximal fixation points are optimally, but not
necessarily, formed in the shape of a loop.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a partially exposed view of an extra-vascular lead
implanted in accordance with a preferred embodiment and connected
to an implantable pulse generator;
[0015] FIG. 2 is a detailed view of an electrode assembly of FIG. 1
shown secured in position on the carotid artery;
[0016] FIG. 3 is a front view of the extra-vascular lead
incorporating the present invention;
[0017] FIGS. 4 and 5 are partially exposed views showing the
details of the configuration of the junction region between the
electrode assembly and the lead body; and
[0018] FIG. 6 is a side view showing the electrode-main body
junction of the connection apparatus incorporating the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to FIGS. 1 through 5 an extra-vascular electrode
lead 10 will be described that improves strain relief and
strengthens a transition or junction region 14 where electrical
conductors 22, 24 (FIG. 5) carried by an elongated flexible lead
body 12 are joined to individual electrodes 32, 34, 36 at the
distal end 16 of the lead 10. The elongated flexible lead body 12
is made of an insulator material with a connector assembly 21 (FIG.
3) at a proximal end 18 of the lead body 12. In a preferred
embodiment, the connector assembly 21 is connected to a pair of
conductors 22, 24 (FIG. 25) carried within the lead body 12 that
are connected at their distal ends to an electrode assembly 30. The
electrode assembly 30 includes structure or mechanisms, such as
electrode tips 38, for externally securing the electrode assembly
30 to a body part. A distal connection structure 50 is located on
the lead body 12 proximal the electrode assembly 30 to anchor the
lead body 12 to a distal anchor location 52 in the body that
generally moves in concert with the body part to which the
electrode assembly 30 is secured. A proximal connection structure
60 is located on the lead body 12 proximal to the distal connection
structure 50 to anchor the lead body 12 to a proximal anchor
location 62 in the body that is at least partially independent of
movement of the body part to which the electrode assembly 30 is
secured. The lead 10 is implanted such that the distal anchor
location 52 and the proximal anchor location 62 are offset in the
body by a distance C (FIG. 2) that is less than a distance B (FIG.
3) between the distal connection structure 50 and the proximal
connection structure 60 in order to provide strain relief for the
electrode assembly 30 against movement of the body part.
[0020] The connector assembly 21 (FIG. 3) at the proximal end 18 of
lead body 12 is connected to an implantable pulse generator 100
(FIG. 1). The pulse generator 100 is commonly implanted in the
pectoral region of the patient. Although the preferred embodiment
of the present invention will be described with respect to an
implantable baroreflex activation electrode that activates the
baroreflex at the carotid sinus, it will be understood that the
extra-vascular lead 10 in accordance with the present invention can
be used for any number of applications of tissue, nerve or organ
stimulation in the body. While the preferred embodiment will be
described with respect to a baroreflex activation at the carotid
sinus alone, it will also be recognized that the present invention
can be utilized as part of a combination device featuring, for
example, both cardiac sensing/stimulation via intra-vascular
electrical leads, as well as other tissue stimulation by
extra-vascular leads 10 in accordance with the present invention.
The apparatus may be used any time a lead is implanted in tissue
(nerves, muscles, vasculars) that may move independently in the
body. For a more detailed description of the operation and
arrangement of the preferred embodiment of a nerve stimulation
electrical lead 10 for the carotid sinus, reference is made to U.S.
Publ. Appl. Nos. 2003/0060857A1 and 2004/0010303A which describe
extra-vascular electrical leads wrapped around the exterior of the
carotid sinus in order stimulate the baroreflex activation, the
disclosure of each of which is hereby incorporated by
reference.
[0021] As shown in FIGS. 1 and 2, the carotid sinus 110 and carotid
artery 112 may move when the patient swallows or moves his or her
head 120. The extra-vascular lead 10 of the present invention has
been designed to provide a strain relief between the electrode
coils 32, 34, and 36 on the carotid sinus 110 at a distal fixation
point 52. This distal fixation point 52 preferably is along the
artery adventitia or periadventitia that moves in concert with the
carotid sinus 110 to prevent strain from being applied directly to
the carotid sinus 110. In the preferred embodiment, the proximal
fixation point 62 is located proximal to the distal fixation point
along the carotid sheath or adjacent tissue. Proximal fixation
point 62 provides strain relief for relatively larger movement of a
patient's head 120 and enables a loop 70 of the lead body 12 to
become larger or smaller as the distance between distal fixation
point 52 and proximal fixation point 62 varies.
[0022] With reference to FIGS. 4 and 5, a view of the details of
the junction or transition region 14 of the lead 10 is shown. In
the preferred embodiment, electrode assembly 30 includes an outer
electrode coil 32, center electrode coil 34, and outer electrode
coil 36. Coils 32, 34, and 36 are preferably helically-shaped and
at least partially covered by an insulator. Coils 32, 34, and 36
have a proximal end and a distal end opposite the proximal end. The
proximal end of each of the coils 32, 34, and 36 include a
plurality of electrode tips 38 (FIG. 3). The electrode tips 38
serve as contact elements and in the preferred embodiment are
attached to the carotid sinus nerve 110 (FIG. 1), although tips 38
may be attached to a variety of structures including other nerves,
arteries, veins, organs, or tissues while remaining within the
scope of the present invention.
[0023] Coils 32, 34, and 36 are fabricated of a conductive
material. In a preferred embodiment, coils 32, 34, and 36 are
fabricated from a platinum/iridium alloy. A proximal end of coil 34
is shown attached to pin 80, while ends of coils 32 and 36 are
shown attached to pin 82 (FIGS. 4 and 5). This configuration
enables three coils 32, 34, and 36 to be connected into two
conductors 22, 24 via the pins 80, 82.
[0024] In a preferred embodiment, the proximal end of center coil
34 is welded to pin 80. Proximal ends of the coils of electrodes 32
and 36 are welded to pin 82. Most preferably, there are at least
three free turns of the coils 32 and 36 between the end of the pin
82 and the first weld. Likewise, there are at least three free
turns of the electrode coils 34 between the end of the pin 80 and
the first weld. This configuration provides robust weld adhesion by
the respective electrode coils 32, 34, and 36.
[0025] The interaction of pins 80 and 82 with lead body conductors
22, 24 at junction region 14 is shown in FIG. 5. Pin 82 is inserted
into a housing 42 and pin 80 is inserted into a housing 44 such
that pin 82 touches conductor 24 and pin 82 touches conductor 22.
In a preferred embodiment, housings 42 and 44 are crimped to apply
pressure of housings 42 and 44 against pins 82 and 80,
respectively.
[0026] Conductor 22 enters the interior of lead body 12 and is
surrounded by insulator 26. Conductor 24 enters lead body 12 and is
disposed around the exterior of insulator 26. Insulator 28 is
disposed about the exterior of conductor 24, and effectively
isolates lead body 12 from the exterior environment. In this
configuration, insulator 26 also serves to isolate conductor 24
from conductor 22 while combining the two lead conductors 22 and 24
into one compact coil within the lead body 12. Conductors 22, 24
are preferably fabricated from a Cobalt-35 Nickel-20 Chromium-10
Molybdenum alloy with a silver core, although a variety of
materials may be used while remaining within the scope of the
invention.
[0027] In FIG. 6, the distal connection structure 50 is shown in
the preferred embodiment in the form of a first suture pad. First
suture pad 50 is attached at fixation point 52 as shown in FIG. 2.
Suture pad 50 comprises dual suture wings 54, 56 and body 58. Body
58 joins dual suture wings 54 and 56 and surrounds junction 14
while providing strain relief for the electrical lead 10. In
another configuration, body 58 is attached to the exterior of the
lead body 12 at junction 14.
[0028] In the preferred embodiment, the proximal connection
structure 60 is shown in the form of a second suture pad 60 (FIGS.
2 and 3). Second suture pad 60 is attached at proximal fixation
point 62. Suture pad 60 is similar in configuration to suture pad
50 and also includes dual suture wings 64 and 66 that form a strain
relief. Suture pad 60 is attached to, or disposed about the
exterior of lead body 12.
[0029] Although the preferred embodiment of the connection
structures 50, 60 have been described in terms of a suture pad, it
will be recognized that other forms of surgical connection
structures and mechanisms may be used to secure the lead body 12 at
the locations 52, 62. Examples of such other forms of surgical
connection structures and mechanisms would include anchoring or
suture sleeves or similar expansions or bulges of the insulative
material of the lead body to permit more effective suturing,
clasps, snaps or fasteners, hook and latch mechanisms, or adhesive
pads or structures.
[0030] With reference to FIG. 2, selective placement of the distal
and proximal connection structures 50 and 60 at anchor locations 52
and 62 takes up the stress on the lead body 12 caused by body
motion without straining the electrode coils 32, 34, and 36.
Placement of the connection structures allows the physician to
create a strain relief loop 70 that allows the forces from the body
to be absorbed by the loop 70 in lead body 12 rather than the
sutures on the electrode tips 38 or suture wings 50 or 60.
[0031] The design of the present invention is intended to leave
slack in between the two anchor locations 52, 62 to prevent strain
on one fixation point from being transferred longitudinally to the
other fixation point. The slack is optimally, but not required to
be, in the shape of an overlapping loop formed of the lead body 12.
Strain on one fixation point is thus taken up by the slack in the
lead body 12, rather than being transferring to the other
independent fixation point. The arrangement in the form of an
overlapping loop also orients the strain in a more longitudinal
direction, rather than a direction transverse to the lead body as
the portion of the lead body adjacent the fixation points is
oriented more longitudinally going into the loop, rather than
having an immediate curve if the lead body were to be positioned in
the form of a non-overlapping omega-shaped hoop.
[0032] FIGS. 2 and 3 show the preferred ranges of distances for
locating the distal and proximal connection structures 50, 60 and
the distal and proximal locations 52, 62. Distance A between
electrode tips 38 and distal connection structure 50 is at 0.5 cm,
preferably being in the range from 1.0 cm to 5.0 cm. Similarly, the
distance B between the suture pad 50 and suture pad 60 is between
at least 2.5 cm, preferably being in the range from 5.0 cm to 18.0
cm.
[0033] It is to be understood that variations in the present
invention can be made without departing from the novel aspects of
this invention as defined in the claims.
* * * * *