U.S. patent application number 11/343859 was filed with the patent office on 2007-08-02 for medical electrical lead connector assembly.
Invention is credited to Douglas Rentas Torres.
Application Number | 20070178770 11/343859 |
Document ID | / |
Family ID | 37877070 |
Filed Date | 2007-08-02 |
United States Patent
Application |
20070178770 |
Kind Code |
A1 |
Rentas Torres; Douglas |
August 2, 2007 |
MEDICAL ELECTRICAL LEAD CONNECTOR ASSEMBLY
Abstract
A connector for a medical electrical lead includes a single
connector, which delivers three or more conductors to an
implantable medical device (IMD). The connector includes integrated
multiple electrode rings and conductors, and has a modular system
of connector and spacer blocks for routing the conductors to a lead
body.
Inventors: |
Rentas Torres; Douglas;
(Villalba, PR) |
Correspondence
Address: |
MEDTRONIC, INC.
710 MEDTRONIC PARKWAY NE
MINNEAPOLIS
MN
55432-9924
US
|
Family ID: |
37877070 |
Appl. No.: |
11/343859 |
Filed: |
January 31, 2006 |
Current U.S.
Class: |
439/668 |
Current CPC
Class: |
A61N 1/3752 20130101;
Y10S 439/909 20130101; A61N 1/05 20130101 |
Class at
Publication: |
439/668 |
International
Class: |
H01R 24/04 20060101
H01R024/04 |
Claims
1. A connector for connecting conductors of a medical electrical
lead with an implantable medical device, the connector comprising:
a connector body having multiple conductors; and a modular system
of connector blocks for routing and joining the conductors of the
lead with the conductors of the connector body.
2. The connector of claim 1 wherein the connector body has a
proximal end for insertion into the implantable medical device and
a distal end for connecting with the medical electrical lead,
wherein the connector body comprises: a central channel running
through a longitudinal axis of the connector body; multiple
connector rings positioned near a proximal end of the connector
body and conductively linked with the multiple conductors; and a
retainer comprising: a cylindrical body having a proximal end for
inserting in the central channel; and a center bore extending from
a distal end of the cylindrical body and for receiving a coil
conductor of a medical electrical lead.
3. The connector of claim 2 wherein a proximal end of the connector
body is engagable with a connector pin for an implantable medical
device.
4. The connector of claim 3 wherein the connector pin is secured to
the proximal end of the connector body with a locking
mechanism.
5. The connector of claim 4 wherein the locking mechanism comprises
a collar and key that form a yoke to rotatably secure the connector
pin within the center channel of the connector body.
6. The connector of claim 2 wherein the retainer is configured to
be press fit with the central channel of the connector body at a
proximal end, and with a coil sheathing of the medical electrical
lead at a distal end to form an adhesive free connection.
7. The connector of claim 1 wherein the connector blocks include
blocks having connecting mechanisms for conductively joining the
conductors of the lead with conductors of the connector body.
8. The connector of claim 7 wherein the connecting mechanisms
include a pair of rails spaced apart to receive a conductor and
wherein the pair of rails configured to be crimped around the
conductor to form a mechanical connection.
9. The connector of claim 7 wherein the connector blocks having
connecting mechanisms include a pair of connecting mechanisms
positioned on opposite sides of each connector block.
10. The connector of claim 7 wherein the modular system includes
spacer blocks positioned between the connector blocks.
11. The connector of claim 10 wherein each of the spacer blocks
comprises a plurality of channels.
12. The connector of claim 10 wherein the spacer blocks are
comprised of compressible material.
13. The connector of claim 7 wherein the connector blocks include
central bores for positioning the connector blocks around a coil
conductor.
14. The connector of claim 13 wherein the connector blocks are
rotatable around the coil conductor such that the conductors of the
lead can be joined with the multiple conductors without interfering
with each other.
15. A connection system for connecting a plurality of electrical
conductors of a medical electrical lead to a plurality of
conductors of a connector that is insertable into an implantable
medical device, the connection system comprising: a plurality of
connector blocks, each block comprising: a first tooth positioned
on the outer diameter of the block for receiving one of the
plurality of conductors from the connector; and a second tooth
positioned on the outer diameter of the block approximately one
hundred eighty degrees from the first tooth and for receiving one
of the plurality of conductors from the lead; wherein the plurality
of connector blocks are axially aligned in a connector housing and
circumferentially rotated with respect to one another.
16. The connection system of claim 15 wherein the plurality of
connector blocks comprises three connector blocks rotated
approximately one hundred twenty degree from each other.
17. The connection system of claim 15 wherein each of the plurality
of connector blocks is axially aligned on a coil conductor.
18. The connection system of claim 15 wherein the first and second
teeth that are configured to be crimped around the conductors to
form a mechanical and electrical connection.
19. The connection system of claim 15 wherein the connector blocks
are spaced from one other by spacer blocks.
20. The connection system of claim 19 wherein the spacer block
comprises: a channel passing centrally through the block; slots
positioned apart on an outer periphery of the spacer block.
21. The connection system of claim 19 wherein the spacer blocks
comprise compressible material.
22. A medical electrical lead connector comprising: a connector
body having a proximal end for insertion into an implantable
medical device and a distal end for connecting with a medical
electrical lead, the connector body comprising a generally
cylindrical connector body having a central channel running through
the axis of the connector body; a first connector ring positioned
near a proximal end of the connector body; a first conductor wire
embedded in the connector body and extending from the distal end to
the first connector ring, and conductively linked with the first
conductor; and a retainer comprising: a cylindrical body having a
proximal end for inserting in the central channel; a distal end for
receiving a medical electrical lead conductor; and a center bore
extending from the distal end to the proximal end.
23. The medical electrical lead connector of claim 22 wherein the
distal end of the retainer is connectable with sheathing of a
conductor coil.
24. The medical electrical lead connector of claim 23 wherein the
distal end of the retainer receives the sheathing to provide an
adhesive-free connection.
25. The medical electrical lead connector of claim 22 wherein the
proximal end of the retainer is press fit into the first central
channel to form a connection.
26. The medical electrical lead connector of claim 22 wherein the
proximal end of the connector body is engagable with a connector
pin for an implantable medical device.
27. The medical electrical lead connector of claim 26 wherein the
connector pin includes a central channel co-axially aligned with
the first and second central channels for receiving a stylet.
28. The medical electrical lead connector of claim 26 wherein the
connector pin includes a distal end for receiving a proximal end of
an coil conductor coil.
29. The medical electrical lead connector of claim 26 wherein the
connector pin is secured to the proximal end of the connector body
with a locking mechanism.
30. The medical electrical lead connector of claim 22 wherein the
first conductor is connected with the first electrode ring by a
crimping mechanism.
31. The medical electrical lead connector of claim 22 wherein the
connector body includes a second conductor wire embedded in the
connector body and conductively connected with a second electrode
ring near the proximal end of the connector body.
32. The medical electrical lead connector of claim 31 wherein the
connector body includes a third conductor wire embedded in the
connector body and conductively connected with a third electrode
ring near the proximal end of the connector body.
33. The medical electrical lead connector of claim 32 wherein the
first, second and third conductor wires are spaced approximately
one hundred and twenty degrees apart around the connector body.
34. The medical electrical lead connector of claim 32 wherein the
first, second and third conductor wires are integrally formed with
the connector body.
35. The medical electrical lead connector of claim 32 wherein the
first, second and third conductor wires include an insulation layer
to electrically isolate the conductors from each other.
36. A medical lead connector for connecting a lead with an
implantable medical device comprising: a connector body having a
plurality of conductors integrally formed with the connector body;
and a central bore for receiving a conductor.
37. The medical lead connector of claim 36 wherein the connector
body includes a plurality of electrode rings connected with the
plurality of conductors, and integral with the connector body, for
conductively linking the plurality of conductors with circuitry of
the implantable medical device.
38. The medical lead connector of claim 36 wherein each of the
plurality of conductors is spaced around a circumference of the
connector body.
39. The medical lead connector of claim 38 wherein the plurality of
conductors extend beyond a distal face of the connector body.
40. The medical lead connector of claim 36 wherein the central bore
receives an electrode pin for connecting a conductor with circuitry
of an implantable medical device.
41. The medical lead connector of claim 36 wherein the central bore
receives a retainer for joining the connector body with the
lead.
42. The medical lead connector of claim 36 wherein each of the
plurality of conductors is insulated.
43. A retention system for use in a medical electrical lead
including a connector pin and a connector body, the retention
system comprising: a collar comprising: an inner diameter sized to
match an outer diameter of a groove in the connector pin; and an
outer diameter sized to engage a slot in the connector body; and a
key for lockably engaging the inner diameter of the collar such
that the key is prevented from disengaging the collar.
44. The retention system of claim 43 wherein the collar comprises a
pair of notches positioned on the inner diameter.
45. The retention system of claim 44 wherein the key comprises a
pair of teeth for engaging the pair of notches of the collar.
46. The retention system of claim 45 wherein the teeth allow the
key to be engaged with the collar when the collar is inserted in
the slot.
47. The retention system of claim 46 wherein the teeth do not allow
the key to disengage the collar when the collar is inserted in the
slot and the key is inserted in the collar.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to implantable
medical device (IMD) leads for delivering active electrodes to
various places in a human body, such as the heart. In particular,
the present invention relates to connectors for connecting a lead
with an IMD.
[0002] Advances in technology have led to IMDs having increased
capabilities for performing therapeutic, diagnostic and other
functions. Such advances can require the use of leads carrying
additional electrodes, which require additional conductors that run
from the IMD to a distal end of the lead. Recently, high voltage
(HV), quadripolar leads having four conductors have been introduced
for tachyarrythmia management and other applications. These leads
include an industry standard IS-1 connector pin for connecting the
IMD with a typical coil conductor and a sensing electrode conductor
for performing Brady-type pacing.
[0003] In addition, for performing other pacing, sensing,
defibrillation therapy and diagnostic functions, for example, in
the superior vena cava (SVC) or right ventricle (RV), additional
conductors are connected to the IMD with standard DF-1 connector
pins. Thus, these leads require up to three connector pins for
inserting into the IMD. Because an additional connector port is
necessary for each connector pin, the increased number of pins can
result in an increased size of the IMD, which requires a larger
space-volume and may pose hermiticity and patient comfort issues.
Therefore, there is a need for a lead connector capable of
connecting multiple conductors with a single connector pin.
BRIEF SUMMARY OF THE INVENTION
[0004] The present invention is directed to a connector for a
medical electrical lead in which a single connector delivers three
or more conductors to an implantable medical device (IMD). The
invention includes a connector having multiple integrated electrode
rings and conductors, and having a modular system of connector and
spacer blocks for routing the conductors to a lead body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIGS. 1A and 1B show partially cut-away views of a lead
connector of the present invention.
[0006] FIG. 2 shows the distal end of a connector body having three
wire conductors.
[0007] FIG. 3A shows a cross sectional view of a connector assembly
having single layer polytetrafuoroethylene (PTFE) insulated wire
conductors.
[0008] FIG. 3B shows a cross sectional view of a connector assembly
having double layer PTFE insulated wire conductors.
[0009] FIG. 4 shows an electrode ring having a wisdom tooth
connector.
[0010] FIG. 5 shows a locking mechanism for a connector
assembly.
[0011] FIG. 6 shows a transition assembly of the lead connector of
the present invention.
[0012] FIG. 7 shows a connector block having wisdom tooth
connectors.
[0013] FIG. 8 shows a spacer block for use in a transition
assembly.
[0014] FIG. 9 shows a transition assembly comprised of connector
blocks and spacer blocks.
[0015] FIG. 10 shows a transition assembly rigged in a bypass
configuration.
DETAILED DESCRIPTION
[0016] FIGS. 1A and 1B show a partially cut-away views of lead
connector 10, which is used to connect multi-conductor lead 11 with
an implantable medical device (IMD), such as a cardiac pacing pulse
generator or implantable cardioverter defibrillator, through a
single connector. Lead connector 10 is positioned at a proximal end
of lead 11, and is comprised of connector assembly 12 and
transition assembly 13. In the embodiment shown, lead 11 comprises
a quadripolar construction in which three wire conductors
(conductors 14A, 16A, and 18A) and one coil conductor (conductor
20) are delivered to or near the distal end of lead 11. Transition
assembly 13 includes connector blocks 22A, 22B and 22C, which are
used to coordinate the interconnection of the conductors from lead
11 to connector assembly 12.
[0017] In the embodiment described, three wire conductors are used,
however it is contemplated that the lead connector of the present
invention can be adapted for leads having two, four or more wire
conductors. Lead 11 also includes sheathing 24, which comprises a
flexible, protective barrier between the conductors and the body in
which lead 11 is implanted. Sheathing 24 can be formed of silicone,
polyurethane, or a non-porous or dense PTFE.
[0018] Lead connector 10 delivers each of the conductors to a
single uni-axial connector body, such that a single connector links
all four conductors with the IMD. Transition assembly 13 is used to
deliver conductors 14A, 16A, 18A and 20 to connector assembly 12,
which can be fitted with a connector socket of an IMD.
[0019] Connector assembly 12 comprises a universal connection to a
variety of IMDs in which up to four conductors can be linked with
the IMD. Connector assembly 12 is a modular assembly that can be
separately manufactured, assembled and distributed for use with a
variety of leads. Likewise, transition assembly 13 is a modular,
adaptable system that can be configured for linking various leads
having up to four conductors to connector assembly 12.
[0020] Transition assembly 13 connects wire conductors 14A, 16A and
18A of lead 11 with conductors 14B, 16B and 18B of connector
assembly 12, while also allowing coil conductor 20 to travel
uninterrupted from the proximal end to the distal end of lead 11.
Connector block 22B connects wire conductor 14A with wire conductor
14B and electrode ring 26, thus forming a circuit with an electrode
positioned at the distal end of lead 11 for performing sensing
functions within a heart. Connector block 22C connects conductor
16A with wire conductor 16B and electrode ring 28, thus forming a
circuit with, for example, a right ventricle defibrillation coil
electrode (RV defib coil). Connector block 22A connects wire
conductor 18A with wire conductor 18B and electrode ring 30, thus
forming a circuit with, for example, a superior vena cava
defibrillation coil electrode (SVC defib coil). Coil conductor 20,
which runs concurrently through lead connector assembly 10, is
connected with connector pin 38 and is used in conjunction with
electrode ring 26 and wire conductors 14A and 14B in performing
heart pacing functions.
[0021] FIG. 2 illustrates the distal end of connector assembly 12,
showing the distal end of wire conductors 14B, 16B and 18B.
Connector assembly 12 includes connector body 34 and retainer 36.
Wire conductors 14B, 16B and 18B are spaced one hundred twenty
degrees apart around the circumference of connector body 34.
Conductors 14B, 16B and 18B are integrally formed with connector
body 34, such as in a molding process. Wire conductors 14B, 16B and
18B can be selectively cut off of connector body 34 when being
connected with leads having fewer than three wire conductors.
Retainer 36 is inserted into connector body 34 and is used to join
connector assembly 12 with transition assembly 13.
[0022] FIG. 3A shows a cross section of connector assembly 12 of
lead body connector 10 taken along section 3-3 of FIG. 2. FIG. 3A
shows lead connector assembly 12 having a single coating of PTFE
insulation on wire conductors 14B, 16B and 18B. FIG. 3B shows
another embodiment of connector assembly 12 in which wire
conductors 14B, 16B and 18B include a double coating of PTFE
insulation. The embodiments of lead body 10 shown in FIG. 3A and
FIG. 3B are similarly constructed and include like element numbers.
FIGS. 3A and 3B will be discussed concurrently.
[0023] Connector assembly 12 is comprised of electrode rings 26, 28
and 30, connector body 34, retainer 36, connector pin 38, locking
mechanism 40 and wire conductors 14B, 16B and 18B (of which only
wire conductor 14B and 18B can be seen in FIGS. 3A and 3B).
Connector body 34 and retainer 36 are typically comprised of a
urethane material. Wire conductors 14B, 16B and 18B are typically
comprised of silver core wires, but can be of any suitable
construction and material.
[0024] Wire conductors 14B, 16B and 18B are pre-assembled with
electrode rings 26, 28 and 30, respectively. FIG. 4 shows electrode
ring 26, which is also representative of electrode rings 28 and 30.
Electrode ring 26 is comprised of a conducting, non-reactive
material, such as titanium, and typically includes a conductive,
corrosion resistant coating. Electrode ring 26 includes wisdom
tooth connecting mechanism 44, which is comprised of spaced rails
46A and 46B that form channel 48. One of the wire conductors (e.g.
wire conductor 14B) is laid flat into channel 48. Any insulation
around the wire conductor along the segment that interacts with
electrode ring 26 is removed such that a conductive link is formed,
as shown, for example, in FIG. 3B. Rails 46A and 46B are then
crimped inward around the wire conductor, thus forming a mechanical
bond having tensile strength suitable for withstanding tension
imposed on lead connector assembly 10 during installation and
operation of lead 11. The crimping of rails 46A and 46B also
improves the electrical connection between the wire conductor and
electrode ring 26.
[0025] Returning to FIG. 3A, the wire conductor and electrode ring
assemblies are then integrally formed with connector body 34, such
as with a molding process. Wire conductors 14B, 16B and 18B extend
a length d beyond the distal face of connector body 34 in order
that they can be joined with transition assembly 13. Typically,
length d is about three to four inches. Depending on the type of
lead with which connector assembly 12 is intended to be used, the
wire conductors can be selectively trimmed from connector body 34.
For example, if connector assembly 12 is to be used with a lead
having only one wire conductor in addition to a coil conductor, two
of wire conductors 14B, 16B and 18B can be cut off at the distal
face of connector body 34. Alternatively, wire conductors 14B, 16B
and 18B of connector assembly 12 can be joined with other types of
transition assemblies or directly with lead 11. Electrode rings 26,
28 and 30 and wire conductors 14B, 16B and 18B are therefore
assembled to form connector body 34, which is manufactured as a
separate part that can be customized for use in different
applications.
[0026] Once electrode rings 26, 28 and 30 and wire conductors 14B,
16B and 18B are assembled to form connector body 34, connector pin
38 is assembled with coil conductor 20. Connector pin 38, which is
comprised of a conducting material, such as titanium, includes post
50, lumen 52 and circumferential groove 54. Post 50 is inserted
into coil conductor 20, and bonded with a welding or soldering
procedure. Lumen 52 accepts a stylet used to guide lead 11 into a
body during implanting of an IMD. Connector pin 38 also includes
circumferential groove 54, which is used in conjunction with
locking mechanism 40 to retain connector pin 38 with respect to
connector body 34.
[0027] After coil conductor 20 has been assembled with connector
pin 38, connector pin 38 is assembled with connector body 34.
Connector body 34 includes sheathing groove 55, central channel 56
and locking channel 58. Sheathing groove 55 is used to secure a
protective sheathing around transition assembly 13. Connector pin
38 is inserted into central channel 56 of connector body 34, along
with coil conductor 20, until circumferential groove 54 aligns with
locking channel 58. Once they are aligned, locking mechanism 40 can
be assembled with connector body 34.
[0028] As shown in FIG. 5, locking mechanism 40 includes two
interlocking pieces: collar 40A and key 40B. Collar 40A prevents
connector pin 38 from disengaging from connector body 34. Key 40B
prevents collar 40A from disengaging connector pin 38. Collar 40A
is inserted into locking channel 58 and circumferential groove 54
from one side of connector assembly 13, while key 40B is inserted
through the opposite side. The outer extent of collar 40A and key
40B mates with locking channel 58 and the inner extent of collar
40A and key 40B mates with circumferential groove 54. Movement of
connector pin 38 along the axis of connector body 34 is thereby
prevented. Collar 40A includes notches 62A and 62B, which receive
teeth 64A and 64B of key 40B. Teeth 64A and 64B allow key 40B to be
inserted into notches 62A and 62B of collar 40A, but prevent key
40B from disengaging from collar 40A. Once assembled, collar 40A
and key 40B form a circular yoke 60, which allows connector pin 38
to rotate in central channel 56.
[0029] To complete the assembly of connector assembly 12, retainer
36 is placed around coil conductor 20 and inserted into central
channel 56 until flange 66 engages the distal face of connector
body 34. Alternatively, retainer 36 could also be placed around
coil conductor 20 before connector pin 38 is linked with connector
body 34. Retainer 36 provides an additional insulating layer
between coil conductor 20 and electrode rings 26, 28 and 30. The
diameter of retainer 36 is slightly smaller than the diameter of
central channel 56 such that a press fit connection is formed.
There are several advantages of a press fit type connection.
Previously, urethane connector pieces have been joined together
with adhesives that require time to dry and sometimes caused
deformation of the urethane pieces due to melting. Thus,
press-fitting retainer 36 into connector body 34 avoids the
necessity of special equipment and knowledge typically required in
adhesive bonding. The press fit connection also prevents fluid from
seeping into connector body 34. Retainer 36 includes connector post
68, which includes flange 70, for linking connector assembly 12
with transition assembly 13.
[0030] FIG. 6 shows a partial cross sectional view of transition
assembly 13 connected with connector assembly 12. Transition
assembly 13 joins connector assembly 12 with lead 11, and
orchestrates the connection and arrangement of the conductors or
each component. Transition assembly 13 includes first connector
block 22A, second connector block 22B, third connector block 22C
and sheathing 72. Lead 11 includes sheathing 24, multilumen tube
80, coil sheathing 82, and wire conductors 14A, 16A and 18A.
Sheathing 72 and connector assembly 12 are shown in cross section,
while the interior of transition assembly 13 is shown in full to
show the inter-linking of the wire conductors.
[0031] Transition assembly 13 is first linked with connector
assembly 12 with coil conductor 20 and coil sheathing 82. Coil
conductor 20 is inserted into sheathing 82 up to the distal face of
connector body 34. Sheathing 82 fits around post 50 of retainer 36
and is retained by tension in sheathing 82. This connection also
avoids the necessity of adhesive bonding, which has the same
benefits as described above. Coil sheathing 82 runs the length of
transition assembly 13.
[0032] FIG. 7 shows connector block 22, which is representative of
connector blocks 22A-22C. Connector block 22 includes center bore
86, first wisdom tooth connector 88A and second wisdom tooth
connector 88B. Connectors 88A and 88B link wire conductors 14A, 16A
and 18A of lead 11 with wire conductors 14B, 16B and 18B of
connector assembly 12, respectively. Connectors 88A and 88B are
similar in construction to wisdom tooth connector 44 of electrode
ring 42, in that they are comprised of opposing rails to form a
channel in which a conductor is laid. The opposing rails are then
crimped to form a mechanical bond having adequate tensile strength.
The crimp also improves the electrical contact between connector
block 22 and the conductor. Wisdom tooth connectors 88A and 88B are
placed one hundred eighty degrees apart on the outer periphery of
connector block 22; one at the top and one at the bottom. Connector
block 22 can be used, however, in any orientation.
[0033] Connector block 22 is comprised of a conductive body having
a diameter approximating the diameter of connector body 34. The
sides of connector block 22 are trimmed down to allow other
conductors, not attached to connector block 22, to travel past
connector block 22 within transition assembly 13. Typically,
connector block 22 is comprised of titanium, but any acceptable
conductive, non-reactive metal can be used.
[0034] Returning to FIG. 6, wire conductors 14B, 16B and 18B extend
from the distal face of connector body 34 and conductors 14A, 16A
and 18A extend from the proximal end of lead 11. The wire
conductors are joined with connector blocks 22A, 22B and 22C.
Connector blocks 22A, 22B and 22C are spaced equally apart on coil
sheathing 82 and orientated along its axis one hundred twenty
degrees apart, such that each wisdom tooth connector has clear
access to the proximal end of lead 11 and the distal face of
connector body 34. In other words, wisdom tooth connectors are
positioned at 12, 2, 4, 6, 8 and 10 o'clock with respect to the
distal face of connector body 34. Any insulating layers surrounding
conductors 14A, 16A, 18A, 14B, 16B and 18B are removed where the
conductors are to be joined with the wisdom tooth connectors so
that conductive connections can be made.
[0035] Connector block 22B is positioned near the center of
transition assembly 13, with its wisdom tooth connectors positioned
at 12 and 6 o'clock. Wire conductor 18B extends from the top of
connector body 34 to the wisdom tooth connector of connector block
22B at 12 o'clock. Wire conductor 18B is positioned within the
channel of the wisdom tooth connector and the rails are crimped
around conductor 18B to form an electrically conductive connection.
Any excess length of conductor 18B, beyond what is necessary to
completely join with connector block 22B, is cut away. Similarly,
wire conductor 18A extends from near the bottom of lead 11 to the
wisdom tooth connector of connector block 22B at 6 o'clock. Wire
conductor 18A is positioned within the channel of the wisdom tooth
connector and the rails are crimped around conductor 18A to form an
electrically conductive connection. Any excess length of conductor
18A, beyond what is necessary to completely join with connector
block 22B, is cut away. Thus, wire conductor 18A is conductively
linked with wire conductor 18B.
[0036] Connector block 22C is positioned near the proximal end of
transition assembly 13, with its wisdom tooth connectors positioned
at 4 and 10 o'clock. Wire conductor 16B extends from the 4 o'clock
position of connector body 34 to the wisdom tooth connector of
connector block 22C at 4 o'clock. Wire conductor 16B is positioned
within the channel of the wisdom tooth connector and the rails are
crimped around conductor 16B to form an electrically conductive
connection. Any excess length of conductor 16B, beyond what is
necessary to completely join with connector block 22C, is cut away.
Similarly, wire conductor 16A extends from near the bottom of lead
11 and runs past connector blocks 22A and 22B to the wisdom tooth
connector of connector block 22C at 10 o'clock. Wire conductor 16A
is positioned within the channel of the wisdom tooth connector and
the rails are crimped around conductor 16A to form an electrically
conductive connection. Any excess length of conductor 16A, beyond
what is necessary to completely join with connector block 22C, is
cut away. Thus, wire conductor 16A is conductively linked with wire
conductor 16B.
[0037] Connector block 22A is positioned near the distal end of
transition assembly 13, with its wisdom tooth connectors positioned
at 2 and 8 o'clock. Wire conductor 14B extends from the 8 o'clock
position of connector body 34 to the wisdom tooth connector of
connector block 22A at 8 o'clock. Wire conductor 14B is positioned
within the channel of the wisdom tooth connector and the rails are
crimped around conductor 14B to form an electrically conductive
connection. Any excess length of conductor 14B, beyond what is
necessary to completely join with connector block 22A, is cut away.
Similarly, wire conductor 14A extends from near the bottom of lead
11 to the wisdom tooth connector of connector block 22A at 2
o'clock. Wire conductor 14A is positioned within the channel of the
wisdom tooth connector and the rails are crimped around conductor
14A to form an electrically conductive connection. Any excess
length of conductor 14A, beyond what is necessary to completely
join with connector block 22A, is cut away. Thus, wire conductor
14A is conductively linked with wire conductor 14B.
[0038] Once all the conductors have been joined with connector
blocks 22A, 22B and 22C, transition assembly sheathing 72 is
positioned around transition assembly 13. The distal end of
sheathing 72 is fitted around sheathing 24 at the proximal end of
lead 11. The proximal end of sheathing 72 is connected with the
distal end of connector body 34, and is fitted around sheathing
groove 55.
[0039] Transition assembly 13 achieves the electrical connection of
the wire conductors of lead 11 with the wire conductors of
connector assembly 12, while maintaining electrical isolation of
each conductor circuit. In the embodiment shown in FIG. 6, the wire
conductors are covered by a single layer of polytetrafluoroethylene
(PTFE) insulation. It is advantageous to include insulation on each
wire conductor in order to avoid electrical interference with the
signal carried by each conductor within transition assembly 13. In
another, such as shown in FIG. 3B, a second PTFE coating is added
to the conductors to ensure that the signal carried by each
conductor does not produce noise or interference in nearby
conductors, especially in transition assembly 13. The insulating
layers can be added to the conductors during manufacture, such as
during extruding of the wires.
[0040] Transition assembly 13 also provides a flexible junction
that maintains strong tensile strength due to the crimping
mechanism of the wisdom tooth connectors. Although the connector
blocks are discussed as being set at positions relative to the
distal face of connector body 34, this is only intended to describe
their approximate position. Once the connector blocks are
assembled, they are free to rotate around coil sheathing 82, which
also aids in tension dissipation in the conductors and flexibility
of transition section 13.
[0041] In another embodiment of the invention, illustrated in FIGS.
8 and 9, transition assembly 13 is fitted with spacer blocks to
dissipate some of the tension produced in the conductors during
handling of lead 11. FIG. 8 shows spacer block 90, which comprises
a circular disk having central bore 92 and peripheral channels
94A-94F. Central bore 92 allows spacer block 90 to be fitted around
coil sheathing 82, in between connector blocks 22A-22C.
[0042] Peripheral channels 94A-94F allow wire conductors travelling
between connector blocks 22A-22C to be laid across spacer block 90.
Peripheral channels 94A-94F have diameters large enough to accept
insulated wire conductors. Peripheral channels 94A-94F are spaced
around the circumference of spacer block 90 sixty degrees apart
(i.e. at 12, 2, 4, 6, 8 and 10 o'clock with respect to the distal
face of connector body 34). Spacer block 90 provides tension relief
of the wire conductors by preventing wire conductors 14A, 16A, 18A,
14B, 16B and 18B from bending or kinking. Spacer block 90 is
preferably composed of silicone rubber, but can be made of any
suitable insulating and dampening material.
[0043] FIG. 9 shows an embodiment of transition assembly 13
provided with spacer blocks 96 and 98. Conductors 14A, 16A, 18A,
14B, 16B and 18B are shown as connected with connector blocks
22A-22C in FIG. 9. Connector blocks 22A, 22B and 22C are co-axially
aligned on coil sheathing 82 of coil conductor 20, which has been
omitted for clarity. Spacer block 96 is disposed on coil sheathing
82 between connector blocks 22A and 22B, and spacer block 98 is
disposed on coil sheathing 82 between connector blocks 22B and
22C.
[0044] Wire conductor 14B extends distally in the 12 o'clock
position, past connector block 22C and through a channel in spacer
block 98 in the 12 o'clock position and into a wisdom tooth
connecting mechanism of connector block 22B.
[0045] Wire conductor 14A extends proximally in the 6 o'clock
position, past connector block 22A and through a channel in spacer
block 96 in the 6 o'clock position and into a wisdom tooth
connecting mechanism of connector block 22B. Thereby, conductors
14B and 14A are conductively joined at connector block 22B.
[0046] Wire conductor 16B extends distally in the 4 o'clock
position and into a wisdom tooth connecting mechanism of connector
block 22C. Wire conductor 16A extends proximally in the 10 o'clock
position past connector block 22A, through a channel in spacer
block 96 in the 10 o'clock position, past connector block 22B,
through a channel in spacer block 98 in the 10 o'clock position and
into a wisdom tooth connecting mechanism of connector block 22C in
the 10 o'clock position. Thereby, conductors 16B and 16A are
conductively joined at connector block 22C.
[0047] Wire conductor 18B extends distally in the 8 o'clock
position, past connector block 22C, through a channel in spacer
block 98 in the 8 o'clock position, past connector block 22B,
through a channel in spacer block 96 in the 8 o'clock position and
into a wisdom tooth connecting mechanism of connector block 22A in
the 8 o'clock position. Wire conductor 18A extends proximally in
the 2 o'clock position and into a wisdom tooth connecting mechanism
of connector block 22A in the 2 o'clock position. Thereby,
conductors 18B and 18A are conductively joined at connector block
22A.
[0048] Spacer blocks 96 and 98 maintain a general linear shape to
the conductors. Spacer blocks 96 and 98 are also comprised of a
flexible or compressible material that allows transition assembly
13 to flex during handling of lead 11. These features assist in
dissipating stress created in the conductors by preventing the
formation of stress points, such as bends or kinks.
[0049] FIG. 10 shows an alternative embodiment of transition
assembly 13 in which the connector blocks are used to create a
bypass configuration for conductors 100,102 and 104. The bypass
configuration allows a single conductor lead to be connected with a
connector body having two conductors. Conductor 104 extends from a
lead at its distal end to transition assembly 13 at its proximal
end. Conductor 104 is conductively linked to conductor 102 at
conductor block 106, and conductively linked to conductor 100 at
connector block 108. Conductor 104 extends past connector block 106
and is then joined with a connection mechanism of connector block
108. Conductor 104 curves back around to extend past connector
block 108 and into a connecting mechanism of connector block 106.
Conductor 102 extends past connector block 108 and into a
connecting mechanism of connector block 106, while conductor 100 is
joined with a connecting mechanism of connector block 108.
[0050] Conductors 102 and 100 are ultimately connected at their
proximal ends with circuitry of an IMD, and each is responsible for
carrying a distinct signal to or from the circuitry, such as a
sense signal and RV defibrillation pulse. Conductor 104 is
ultimately connected with one or more electrodes positioned within
body tissue at the distal end of conductor 104. The electrode(s)
connected to conductor 104 may perform both sensing/pacing and
defibrillation functions, depending on whether conductor 100 or 102
is active.
[0051] Although the present invention has been described with
reference to preferred embodiments, workers skilled in the art will
recognize that changes may be made in form and detail without
departing from the spirit and scope of the invention.
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