IMPLANTABLE MEDICAL ELECTRICAL LEAD CONNECTOR ASSEMBLIES AND METHODS OF MANUFACTURE

• US 20150165217A1
• Filed: 03/05/2014
• Published: 06/18/2015
• Est. Priority Date: 12/18/2013
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hughes, Jonathan A.
• Granted Patent: US 9,101,776 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0558 Anchoring or fixation means therefor
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/3752 Details of casing-lead connections
• CPC Class Codes: A61N 1/3968 Constructional arrangements, e.g. casings A61N1/375 takes precedence
• CPC Class Codes: H01R 13/516 Means for holding or embracing insulating body, e.g. casing , hoods
• CPC Class Codes: H01R 2201/12 for medicine and surgery
• CPC Class Codes: H01R 24/58 Contacts spaced along longitudinal axis of engagement
• CPC Class Codes: H01R 43/16 for manufacturing contact members, e.g. by punching and by bending
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base

Abstract

An implantable lead connector assembly includes contact rings, and a bulk of insulation, which includes sealing surfaces and a shank defining a distal end of the bulk. One or more conductor pins extend within the bulk and have distal ends protruding distally therefrom to be exposed alongside the shank; and an inner surface of each contact ring may have a proximal end of a corresponding conductor pin coupled thereto. The sealing surfaces, in conjunction with outer contact surfaces of the contact rings, which are interspersed therebetween, define a uniform outer diameter for the connector assembly. The bulk of insulation may be formed in two parts, wherein a primary bulk is formed around a core and includes circuit-support and shank segments. A secondary bulk, which includes the aforementioned sealing surfaces, is injection molded around the primary bulk, after positioning the contact rings and corresponding conductor pins on the circuit-support segment thereof.

Claims

1. A connector assembly for an implantable medical electrical lead, the assembly having a central longitudinal axis and a uniform outer diameter conforming to a requirement for the connector to mate with a connector receptacle of an implantable medical device, and the assembly comprising:

a plurality of contact rings extending around the central longitudinal axis and being spaced apart from one another along a length of the assembly, each of the contact rings having an inner surface, and an outer contact surface, each outer contact surface defining the uniform outer diameter;

a bulk of insulation supporting the plurality of contact rings and isolating the contact rings from one another, the bulk of insulation including a plurality of sealing surfaces, and a shank, each sealing surface also defining the uniform outer diameter of the assembly, the shank defining a distal end of the bulk of insulation, and the shank having an asymmetric profile, a first sealing surface of the plurality of sealing surfaces extending from a proximal end of the bulk of insulation to a first ring of the plurality of contact rings, a second sealing surface of the plurality of sealing surfaces extending between the first contact ring and a second contact ring of the plurality of contact rings, and a third sealing surface of the plurality of sealing surfaces extending distally from the second contact ring;

at least one conductor pin extending within the bulk of insulation, a distal end of each conductor pin protruding distally from the bulk of insulation and being exposed alongside the shank thereof, and a proximal end of a first conductor pin of the at least one conductor pin being coupled to the inner surface of the first contact ring; and

a core extending within the bulk of insulation, the core being aligned along the central longitudinal axis of the assembly.

2. The assembly of claim 1, wherein the shank of the bulk of insulation includes a proximal portion and a distal portion, the proximal portion being defined by an external groove formed therein, the groove extending around the central longitudinal axis, and the distal portion being defined by the asymmetric profile.

3. The assembly of claim 1, wherein the core includes an outer surface to which a proximal end of a second conductor pin of the at least one conductor pin is coupled.

4. The assembly of claim 3, wherein the second conductor pin has a bend formed therein, the bend being located between the proximal end of the second conductor pin and a remainder thereof such that the remainder is spaced outward from the outer surface of the core.

5. The assembly of claim 3, further comprising a terminal connector pin coupled to the core and protruding proximally from the proximal end of the bulk of insulation.

6. The assembly of claim 1, wherein the at least one conductor pin comprises a plurality of conductor pins, the distal ends of the plurality of conductor pins being spaced apart from one another and spaced approximately equidistant from the central longitudinal axis.

7. The assembly of claim 6, wherein:

the plurality of conductor pins includes the first conductor pin, a second conductor pin, and a third conductor pin; and

the plurality of contact rings includes the first and second contact rings and a third contact ring, a proximal end of the second conductor pin being coupled to the inner surface of the second contact ring, and a proximal end of the third conductor pin being coupled to the inner surface of the third contact ring.

8. The assembly of claim 7, wherein the core includes an outer surface to which a proximal end of a fourth conductor pin of the plurality of conductor pins is coupled.

9. The assembly of claim 6, further comprising:

a transition fitting joined to the shank of the bulk of insulation, the fitting comprising a lumen, and at least two peripheral grooves, the lumen being sized to receive an inner portion of a body of the lead; and

wherein each groove of the transition fitting supports the distal end of a corresponding conductor pin of the plurality of conductor pins; and

each groove of the transition fitting is sized to receive a corresponding conductor of a plurality of conductors of the body of the lead, such that each conductor pin of the assembly can be coupled to the corresponding lead conductor within the corresponding groove, when the inner portion of the lead body is received in the lumen of the fitting.

10. The assembly of claim 9, wherein the transition fitting further comprises a strain relief portion extending distally from the grooves, the lumen of the fitting extending within the strain relief portion, and the strain relief portion being sized to fit between the inner portion of the lead body and the plurality of conductors of the lead body, when the inner portion is received in the lumen of the fitting, and each conductor of the plurality of conductors is received in the corresponding groove of the fitting.

11. The assembly of claim 9, wherein:

the transition fitting further comprises a strain relief portion extending distally from the grooves, the strain relief portion including a plurality of longitudinal slots, each slot aligned with a corresponding groove and extending therefrom to an open end at a distal end of the fitting;

the lumen of the fitting extends within the strain relief portion; and

the strain relief portion is sized to fit around the inner portion of the lead body, the plurality of conductors of the lead body, and an outer insulation layer of the lead body, which overlays the plurality of conductors, when the inner portion is received in the lumen, and each conductor of the plurality of conductors is received in the corresponding groove, via the corresponding slot.

12. A subassembly for a connector assembly of an implantable medical electrical lead, the subassembly comprising:

a bulk of insulation including a circuit-support segment and a shank segment, the circuit-support segment extending along a length of a central longitudinal axis of the subassembly, from a proximal end of the circuit-support segment to a distal end of the circuit-support segment, the shank segment extending distally, along the central longitudinal axis, from the distal end of the circuit-support segment, and the circuit-support segment including three longitudinally-extending open channels;

a core extending within the bulk of insulation, the core being aligned along the central longitudinal axis of the assembly;

a plurality of contact rings mounted around the circuit-support segment of the bulk of insulation and spaced apart from one another along the length thereof, an outer contact surface of each of the plurality of contact rings defining a uniform outer diameter, the uniform outer diameter conforming to a requirement of the connector assembly to mate with a connector receptacle of an implantable medical device; and

a first conductor pin extending within a first channel of the three open channels of the circuit-support segment of the bulk of insulation, a proximal end of the first conductor pin being coupled to an inner surface of a first contact ring of the plurality of contact rings, and a distal end of the first conductor pin being exposed alongside the shank segment of the bulk of insulation.

13. The subassembly of claim 12, wherein the shank segment of the bulk of insulation has an asymmetric profile.

14. The subassembly of claim 12, further comprising:

a second conductor pin extending within the bulk of insulation, the second conductor pin including a proximal end coupled to an outer surface of the core, within the bulk of insulation, and a distal end protruding from the distal end of the circuit-support segment of the bulk of insulation, the distal end of the second conductor pin being exposed alongside the shank segment of the bulk of insulation; and

a terminal connector pin coupled to a proximal end of the core in proximity to the proximal end of the circuit-support segment of the bulk of insulation.

15. The subassembly of claim 12, further comprising a second conductor pin, the second conductor pin extending within a second channel of the three open channels of the circuit-support segment of the bulk of insulation, a proximal end of the second conductor pin being coupled to an inner surface of a second contact ring of the plurality of contact rings, and a distal end of the second conductor pin being exposed alongside the shank segment of the bulk of insulation.

16. The subassembly of claim 15, further comprising a third conductor pin, the third conductor pin extending within a third channel of the three open channels of the circuit-support segment of the bulk of insulation, a proximal end of the third conductor pin being coupled to an inner surface of a third contact ring of the plurality of contact rings, and a distal end of the third conductor pin being exposed alongside the shank segment of the bulk of insulation.

17. The subassembly of claim 16, wherein the distal ends of the first, second and third conductor pins are spaced apart from one another and spaced approximately equidistant from the central longitudinal axis.

18. The subassembly of claim 16, further comprising:

a fourth conductor pin extending within the bulk of insulation, the fourth conductor pin including a proximal end coupled to an outer surface of the core, within the bulk of insulation, and a distal end protruding from the distal end of the circuit-support segment of the bulk of insulation, the distal end of the fourth conductor pin being exposed alongside the shank segment of the bulk of insulation; and

a terminal connector pin coupled to a proximal end of the core in proximity to the proximal end of the circuit-support segment of the bulk of insulation.

19. The subassembly of claim 18, wherein the distal ends of the first, second, third and fourth conductor pins are spaced apart from one another and spaced approximately equidistant from the central longitudinal axis.

20. A method for manufacturing a modular assembly for a connector of an implantable medical electrical lead, such that the assembly has a uniform outer diameter conforming to a requirement for the lead connector to mate with a connector receptacle of an implantable medical device, and the method comprising:

forming a primary bulk of insulation around a core so that the primary bulk of insulation includes a circuit-support segment and a shank segment, the circuit-support segment extending along a central longitudinal axis, from a proximal end thereof to a distal end thereof, the shank segment extending distally from the distal end of the circuit-support segment, and the circuit-support segment including first, second, and third open channels;

mounting first, second, and third contact rings onto the circuit-support segment of the primary bulk of insulation so that the contact rings are spaced apart from one another along a length of the circuit-support segment;

inserting a first conductor pin into the first open channel of the circuit-support segment of the primary bulk of insulation, a proximal end of the first conductor pin being coupled to an inner surface of the first contact ring;

positioning the primary bulk of insulation with the mounted contact rings and the inserted first conductor pin within a mold assembly; and

injecting an insulative material through a gate of the mold assembly to form a secondary bulk of insulation, the secondary bulk of insulation extending between the primary bulk of insulation and the contact rings, and around the first conductor pin, the secondary bulk of insulation including a proximal end, a distal end, and first, second, third, and fourth sealing surfaces, a distal end of the first conductor pin extending distally from the distal end of the secondary bulk of insulation, the first sealing surface extending between the proximal end of the secondary bulk of insulation and the first contact ring, the second sealing surface extending between the first and second contact rings, the third sealing surface extending between the second and third contact rings, and the fourth sealing surface extending distally from the third contact ring toward the distal end of the secondary bulk of insulation; and

wherein an outer contact surface of each of the three contact rings and all four sealing surfaces of the secondary bulk of insulation define the uniform outer diameter of the modular assembly.

21. The method of claim 20, further comprising:

coupling a second conductor pin to the core, before forming the primary bulk of insulation, the primary bulk of insulation extending around the second conductor pin but leaving a distal end exposed alongside the shank segment of the primary bulk of insulation; and

forming a junction to couple a terminal connector pin to a proximal end of the core, before forming the primary bulk of insulation; and

wherein the secondary bulk of insulation extends around the junction;

a proximal end of the terminal connector pin protrudes from the proximal end of the secondary bulk of insulation; and

the distal end of the second conductor pin extends distally from the distal end of the secondary bulk of insulation.

22. The method of claim 20, further comprising joining a transition fitting to the primary and secondary bulks of insulation;

and wherein the joining comprises;

orienting an asymmetric lumen of the transition fitting to mate with an asymmetric profile of the shank segment of the primary bulk of insulation;

inserting the shank segment into the asymmetric lumen of the transition fitting, such that the distal end of the first conductor pin extends within a peripheral groove of the transition fitting; and

bonding the transition fitting to the distal end of the secondary bulk of insulation.