MEDICAL DEVICES INCLUDING POLYISOBUTYLENE BASED POLYMERS AND DERIVATIVES THEREOF

• US 20110054581A1
• Filed: 09/02/2010
• Published: 03/03/2011
• Est. Priority Date: 09/02/2009
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Desai, Shrojalkumar, Reddy, G. Shantanu
• Granted Patent: US 8,644,952 B2
• Time in Patent Office: Days
• US Class Current: 607/116
• CPC Class Codes: A61L 31/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/3206 aliphatic
• CPC Class Codes: C08G 18/4063 Mixtures of compounds of group C08G18/62 with other macromolecular compounds
• CPC Class Codes: C08G 18/4854 Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
• CPC Class Codes: C08G 18/6204 Polymers of olefins unsaturated polymers of conjugated dienes C08G18/69
• CPC Class Codes: C08G 18/6705 Unsaturated polymers not provided for in the groups C08G18/671, C08G18/6795, C08G18/68 or C08G18/69
• CPC Class Codes: C08G 18/7671 containing only one alkylene bisphenyl group
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing

Abstract

The present invention is directed to a medical electrical lead including an insulative lead body formed, at least in part, from a polyisobutylene urethane, urea or urethane/urea copolymer. In some applications, the lead body can include at least one outer tubular insulator and/or an inner elongated member formed from a polyisobutylene urethane, urea or urethane/urea copolymer. Portions of the lead body formed form the polyisobutylene urethane, urea or urethane/urea copolymer can be either extruded or molded.

Claims

1. An implantable medical lead comprising:

an elongated lead body comprising a lumen, at least one conductor disposed within the lumen and at least one electrode operatively coupled to the conductor and disposed along the lead body, wherein the lead body has a Shore hardness from about 30A to about 75D and comprises a polyisobutylene urethane, urea or urethane/urea copolymer comprising soft polymer segments and hard polymer segments;

wherein the soft polymer segments comprise a polyisobutylene segment and at least one additional polymer segment comprising a residue of;

a polyether diol, a fluorinated polyether diol, a fluoropolymer diol, a polyester diol, a polyacrylate diol, a polymethacrylate diol, a polysiloxane diol, a fluorinated polysiloxane diol, or a polycarbonate diol; and

wherein a weight ratio of soft segments to hard segments in the copolymer ranges from 50;

50 to 90;

10.

2. The implantable medical lead according to claim 1, wherein a weight ratio of polyisobutylene to additional polymer ranges from about 70:

30 to about 90;

10.

3. The implantable medical lead according to claim 1, wherein the soft segments comprise a polyisobutylene segment and a residue of a polyether diol.

4. The implantable medical lead according to claim 1, wherein the soft segments comprise a polyisobutylene segment and a residue of a polytetramethylene oxide diol.

5. The implantable medical lead according to claim 4, wherein a weight ratio of polyisobutylene to polytetramethylene oxide ranges from about 70:

30 to about 90;

10.

6. The implantable medical lead according to claim 1, wherein the polyisobutylene segment comprises a residue of a saturated polyisobutylene diol.

7. The implantable medical lead of claim 1 wherein the lead body comprises an inner lumen and an inner surface of the lumen comprises the copolymer.

8. The implantable medical lead according to claim 7, wherein the conductor is a coiled conductor having a co-radial configuration and wherein the inner surface is disposed over an outer surface of the coiled conductor.

9. The implantable medical lead according to claim 1, wherein the lead body comprises an inner tubular layer and an outer tubular layer, wherein at least one of the inner and outer tubular layers comprises a polyisobutylene urethane, urea or urethane/urea copolymer.

10. The implantable medical lead according to claim 9, wherein the lead comprises first and second coiled conductors having a co-axial configuration, wherein the inner tubular layer is disposed between the first and the second conductors, and wherein the outer tubular layer is disposed over the second coiled conductor.

11. The implantable medical lead according to claim 1, wherein the lead body comprises a Shore hardness between about 30A and 100A.

12. An implantable medical lead comprising:

an elongated lead body comprising a lumen, at least one conductor disposed within the lumen and at least one electrode operatively coupled to the conductor and disposed along the lead body, wherein the lead body comprises a polyisobutylene urethane, urea or urethane/urea copolymer in each of a proximal region comprising a first Shore hardness, a middle region comprising a second Shore hardness and a distal region comprising a third Shore hardness;

wherein the copolymer comprises soft polymer segments and hard polymer segments and wherein the soft polymer segments comprise a polyisobutylene segment and at least one additional polymer segment comprising a residue of;

a polyether diol, a fluorinated polyether diol, a fluoropolymer diol, a polyester diol, a polyacrylate diol, a polymethacrylate diol, a polysiloxane diol, a fluorinated polysiloxane diol, or a polycarbonate diol.

13. The implantable medical lead according to claim 12, wherein the distal region comprises a Shore hardness from about 30A to about 70A.

14. The implantable medical lead according to claim 12, wherein the middle region comprises a Shore hardness from about 60A to about 85A.

15. The implantable medical lead according to claim 12, wherein the proximal region comprises a Shore hardness from about 85A to about 100A.

16. The implantable medical lead according to claim 12, wherein the lead body further comprises one or more transition regions adjacent the proximal, middle or distal regions, and wherein transition regions have a different shore hardness than the adjacent proximal, middle or distal region.

17. The implantable medical lead according to claim 12, wherein additional soft segment in each region comprises a residue of a polytetramethylene oxide diol.

18. The implantable medical lead according to claim 17, wherein a weight ratio of polyisobutylene to polytetramethylene oxide in each region ranges from about 70:

30 to about 90;

10.

19. The implantable medical lead according to claim 12, wherein a weight ratio of soft segments to hard segments in the copolymer in each region ranges from 50:

50 to 90;

10.

20. The implantable medical lead according to claim 12, wherein the proximal region comprises a first weight ratio of soft segments to hard segments in the polyisobutylene urethane, urea or urethane/urea copolymer, the middle region comprises a second weight ratio of soft segments to hard segments in the polyisobutylene urethane, urea or urethane/urea copolymer, and the distal region comprises a third weight ratio of soft segments to hard segments in the polyisobutylene urethane, urea or urethane/urea copolymer.

21. An implantable medical lead comprising:

a flexible, elongated lead body comprising an inner tubular member including at least one longitudinal lumen therethrough;

at least one conductor extending through the at least one lumen of the inner tubular member, the conductor including an electrode having an exposed surface relative to the lead body; and

at least one polymeric component connected to at least one of the lead body, conductor and electrode, the at least one polymeric component comprising a polyisobutylene urethane, urea or urethane/urea copolymer, wherein the copolymer comprises soft polymer segments and hard polymer segments and wherein the soft polymer segments comprise a polyisobutylene segment and at least one additional polymer segment comprising a residue of;

a polyether diol, a fluorinated polyether diol, a fluoropolymer diol, a polyester diol, a polyacrylate diol, a polymethacrylate diol, a polysiloxane diol, a fluorinated polysiloxane diol, or a polycarbonate diol.

22. The implantable medical lead according to claim 21, wherein the at least one polymeric component comprises a lead terminal, terminal pin, a lead tip, O-ring, seal or a header.

23. The implantable medical lead according to claim 21, wherein the at least one polymeric component comprises a thin film disposed on or adjacent to the exposed surface of the electrode.

24. The implantable medical lead according to claim 21, wherein the thin film comprises a plurality of electrospun fibers comprising the polyisobutylene urethane, urea or urethane/urea copolymer.

25. The implantable medical lead according to claim 21 wherein the thin film is disposed on a portion of the conductor.

26. The implantable medical lead according to claim 21, wherein the at least one polymeric layer comprises a polymer tube disposed adjacent to the exposed surface of the electrode.

27. A method of manufacturing an implantable medical lead comprising:

forming a lead body portion having a Shore hardness from about 30A to about 75D from a polymer material comprising a polyisobutylene urethane, urea or urethane/urea copolymer, wherein the copolymer comprises soft polymer segments and hard polymer segments in a weight ratio of from 50;

50 to 90;

10, wherein the soft polymer segments comprise a polyisobutylene segment and at least one additional polymer segment comprising a residue of;

a polyether diol, a fluorinated polyether diol, a fluoropolymer diol, a polyester diol, a polyacrylate diol, a polymethacrylate diol, a polysiloxane diol, a fluorinated polysiloxane diol, or a polycarbonate diol; and

associating the lead body portion with a conductor and an electrode connected to the conductor.

28. The method of claim 27 wherein the lead body portion is formed by extruding or injection molding the polymer material.

29. The method according to claim 27, wherein the polyisobutylene urethane, urea or urethane/urea copolymer comprises an unsaturated polyisobutylene segment.

30. The method according to claim 27, wherein the polyisobutylene urethane, urea or urethane/urea copolymer comprises a polyisobutylene segment formed from a saturated polyisobutylene diol having a number average molecular weight of between about 1000 and 5000.

31. The method according to claim 27, wherein the polyisobutylene urethane, urea or urethane/urea copolymer comprises a polytetramethylene oxide segment formed from a polytetramethylene oxide diol having a number average molecular weight of between about 500 and 3000.

32. The method according to claim 27, further comprising the step of combining the polyisobutylene urethane, urea or urethane/urea copolymer with at least one processing aid or stabilizer to form a mixture.

33. The method according to claim 32, further comprising the step of extruding the lead body portion from the mixture.

34. The method according to claim 32, wherein the stabilizer is a plasticizer or wax and wherein the stabilizer is an antioxidant or thermal stabilizer.

35. The method according to claim 27, wherein forming the lead body portion comprises forming a proximal region including a first shore hardness, a middle region comprising a second shore hardness and a distal region comprising a third shore hardness, wherein each of the first, second and third regions comprises the polyisobutylene urethane, urea or urethane/urea copolymer.

36. The method according to claim 27, wherein the proximal region comprises a first weight ratio of soft segments to hard segments in the polyisobutylene urethane, urea or urethane/urea copolymer, the middle region comprises a second weight ratio of soft segments to hard segments in the polyisobutylene urethane, urea or urethane/urea copolymer, and the distal region comprises a third weight ratio of soft segments to hard segments in the polyisobutylene urethane, urea or urethane/urea copolymer.

37. The method according to claim 27 wherein the forming step comprises electrospinning the polyisobutylene urethane, urea or urethane/urea copolymer.