Implantable device having porous surface with carbon coating

• US 4,542,752 A
• Filed: 04/22/1983
• Issued: 09/24/1985
• Est. Priority Date: 04/22/1983
• Status: Expired due to Fees

• Current Assignee: Telectronics Pacing Systems, Inc (Abbott Laboratories)
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: MacGregor, David C., DeHaan, Abel
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Falk, Steven
• Application Number:
  US06/487,460
• Time in Patent Office: 886 Days
• Field of Search: 128/784-786, 128/419 R, 128/419 P, 128/635, 128/419 PG, 128/303.14, 128/303.17, 29/885, 29/855, 29/874, 29/875, 29/880
• US Class Current: 607/119
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: Y10T 29/49224 with coating

Abstract

An implantable device is provided by a process that includes preparing a substrate which has a low impedance carbon coating over a porous substrate. The carbon coating is a carbon lattice formed by plasma depositing a hydrocarbon within an energized gaseous environment. The implantable device is one into which tissue ingrowth is desired, such as electrodes for cardiac and neurostimulation.

Claims

1. A device or appliance that is implantable in organic tissue, comprising:

an electrically conductive shaped element having a shaped substrate member that is electrically conductive and porous to provide a convoluted surface for enhancing organic tissue ingrowth thereinto; and

a low impedance carbon coating over said electrically conductive porous shaped substrate member, said low impedance carbon coating having a carbon lattice structure, said carbon lattice structure being a plasma deposit of carbon laid down on a generally molecular level, said carbon lattice structure providing a porous surface that had been substantially shaped by and conformally coated onto said convoluted surface of the electrically conductive porous shaped substrate member;

wherein

said low impedance carbon coating lattice structure plasma deposit having been laid down by subjecting said electrically conductive porous shaped substrate member to a gaseous environment including a hydrocarbon and energizing the gaseous environment to degrade the hydrocarbon into carbon and hydrogen and to form said carbon lattice structure.

2. The implantable device or appliance according to claim 1, wherein said porous shaped substrate member is a porous metal structure.

3. The implantable device or appliance according to claim 1, wherein said porous shaped substrate member is a porous sintered metal.

4. The implantable device or appliance according to claim 1, wherein said shaped substrate member includes a sintered metal as the porous convoluted surface thereof, said sintered metal underlying said low impedance carbon coating lattice structure and overlying a shaped substrate core.

5. The implantable device or appliance according to claim 1, wherein said porous shaped substrate member includes a plurality of metal spheres.

6. An electrically conductive shaped element as a portion of a device or appliance that is implantable in organic tissue, comprising:

a shaped substrate member that is electrically conductive and porous to provide a convoluted surface for enhancing organic tissue ingrowth thereinto; and

a low impedance carbon coating over said electrically conductive porous shaped substrate member, said low impedance carbon coating having a carbon lattice structure, said carbon lattice structure being a plasma deposit of carbon laid down on a generally molecular level, said carbon lattice structure providing a porous surface that had been substantially shaped by and conformally coated onto said convoluted surface of the electrically conductive porous shaped substrate member;

wherein

said low impedance carbon coating lattice structure plasma deposit having been laid down by subjecting said electrically conductive porous shaped substrate member to a gaseous environment including a hydrocarbon and energizing the gaseous environment to degrade the hydrocarbon into carbon and hydrogen and to form said carbon lattice structure.

7. The shaped element according to claim 6, wherein said porous shaped substrate member has a porous metal surface.

8. The shaped element according to claim 6, wherein said shaped substrate member includes a sintered metal as the porous convoluted surface thereof, said sintered metal underlying said low impedance carbon coating lattice structure and overlying a shaped substrate core.

9. The shaped element according to claim 6, wherein said porous shaped substrate member includes a plurality of metal spheres.

10. A process for making a device or appliance that is implantable in organic tissue and that has a convoluted surface for enhancing organic tissue ingrowth thereinto, comprising:

providing an electrically conductive shaped element having a shaped substrate member that is electrically conductive and porous, thereby providing the covoluted surface;

plasma depositing a carbon lattice structure onto said porous convoluted surface of the electrically conductive shaped substrate member, said carbon lattice structure being a low impedance carbon coating onto said convoluted surface that is laid down on a generally molecular level, said plasma depositing including the steps of;

subjecting said porous convoluted surface of the electrically conductive porous shaped substrate member to a gaseous environment including a hydrocarbon; and

energizing the gaseous environment to degrade the hydrocarbon into carbon and hydrogen to form the carbon lattice structure coated onto said porous convoluted surface of the electrically conductive porous shaped substrate member, wherein said energizing step includes forming the carbon lattice structure as a porous surface by conforming the carbon into a carbon lattice structure that is substantially shaped by and conformally coated onto said porous convoluted surface.

11. The process of claim 10, wherein said plasma depositing includes a glow discharge procedure.

12. The process of claim 10, wherein the porous convoluted surface is formed by metal sintering.

13. The process of claim 10, wherein the gaseous environment includes an alkene.

14. The process of claim 10, wherein the gaseous environment includes an inert gas.

15. The process of claim 10, wherein the gaseous environment includes a hydrocarbon selected from the group consisting of hydrocarbons having one or more double bonds, hydrocarbons having triple bonds, and saturated hydrocarbons.

16. The process of claim 10 , wherein the gaseous environment includes a hydrocarbon having one or more double bonds.

17. The process of claim 10, further including pretreating the porous convoluted surface by plasma techniques, said pretreating step being before said plasma depositing of the carbon lattice structure.

18. The process of claim 10, wherein said energizing step includes polymerizing the hydrocarbon.

19. The process of claim 10, further including pretreating the porous convoluted surface by subjecting the porous convoluted surface to a glow discharge gaseous environment including a pretreatment agent and energizing the pretreatment gaseous environment.

20. The process of claim 10, further including pretreating the porous convoluted surface by subjecting the porous convoluted surface to a glow discharge gaseous environment including a tetrahalogenated alkane and energizing the pretreatment gaseous environment.

21. The process of claim 10, further including pretreating the porous convoluted surface by subjecting the porous convoluted surface to a glow discharge gaseous environment including a tetrafluoromethane or bromotrifluoromethane and energizing the pretreatment gaseous environment.

22. The process of claim 10, further including pretreating the porous convoluted surface within a gaseous environment including an inert gas and a pretreatment agent.

23. The process of claim 10, further including a pretreatment step which is a plasma cleaning that includes subjecting the porous convoluted surface to an inert gas environment and energizing that environment.

24. The process of claim 10, further including a plurality of pretreatment steps including a plasma cleaning step that includes subjecting the porous convoluted surface to an inert gas environment and energizing that environment, followed by a further pretreatment step that is a plasma etching step utilizing a halogenated alkane within a gaseous environment.

25. The process of claim 10, wherein said gaseous environment includes an inert gas added to a vacuum environment.

26. The process of claim 10, wherein said gaseous environment is within an enclosed chamber.

27. The process of claim 10, wherein said energizing step includes imparting radio frequency energy which raises the temperature of the substrate to between about 300°

and 370°

C.