Treatments to reduce thrombogeneticity in heart valves made from titanium and its alloys
First Claim
1. A method for coating a substrate comprised of titanium with diamond-like carbon comprising:
- exposing said substrate to a vacuum at a pressure of about 10-5 torr or less;
heating said substrate to between at least about 600°
C.-650°
C. (1112°
F.-1202°
F.);
depositing silicon onto said substrate in an amount sufficient to form an inner bonding layer of titanium-silicide cohesively bonded to an outer layer of silicon;
substantially simultaneous with said depositing of silicon, bombarding said deposited silicon with a first energetic beam of ions at a first energy, a first ion density, and for a first amount of time sufficient to form said inner titanium-silicide bonding layer cohesively bonded to said outer layer of silicon;
condensing a diamond-like carbon precursor onto said outer layer of silicon at a second temperature and for a second amount of time sufficient to form a film of precursor molecules tin said outer layer of silicon, wherein said second temperature is sufficiently low that said diamond-like carbon precursor is not vaporized off of said substrate;
substantially simultaneous with said condensing of a diamond-like carbon precursor, bombarding said diamond-like carbon precursor with a second energetic beam of ions at a second energy, a second ion density, and for a third amount of time sufficient to form an inner silicon carbide layer cohesively bonded to an outer coating of diamond-like carbon.
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Accused Products
Abstract
The present invention provides a method for coating a titanium based component with diamond-like carbon to reduce the thrombogeneticity of the component. In a preferred embodiment, the titanium based component is a heart valve.
According to the present invention, the component is placed in a vacuum chamber and heated to about 600° -650° C. (1112°-1202° F.). Thereafter, silicon is then deposited onto the component, and the component is simultaneously bombarded with a beam of energetic ions to form a metal-silicide bonding layer. The component then is cooled to at least about 100° C. (212° F.), preferably about 80° C. (176° F.), and a diamond-like carbon precursor is condensed onto the metal-silicide bonding layer. The precursor is simultaneously bombarded with a beam of energetic ions to form a coating of diamond-like carbon.
143 Citations
25 Claims
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1. A method for coating a substrate comprised of titanium with diamond-like carbon comprising:
-
exposing said substrate to a vacuum at a pressure of about 10-5 torr or less; heating said substrate to between at least about 600°
C.-650°
C. (1112°
F.-1202°
F.);depositing silicon onto said substrate in an amount sufficient to form an inner bonding layer of titanium-silicide cohesively bonded to an outer layer of silicon; substantially simultaneous with said depositing of silicon, bombarding said deposited silicon with a first energetic beam of ions at a first energy, a first ion density, and for a first amount of time sufficient to form said inner titanium-silicide bonding layer cohesively bonded to said outer layer of silicon; condensing a diamond-like carbon precursor onto said outer layer of silicon at a second temperature and for a second amount of time sufficient to form a film of precursor molecules tin said outer layer of silicon, wherein said second temperature is sufficiently low that said diamond-like carbon precursor is not vaporized off of said substrate; substantially simultaneous with said condensing of a diamond-like carbon precursor, bombarding said diamond-like carbon precursor with a second energetic beam of ions at a second energy, a second ion density, and for a third amount of time sufficient to form an inner silicon carbide layer cohesively bonded to an outer coating of diamond-like carbon. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A medical implant having at least one substrate comprising titanium coated with a sequential gradient as follows:
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silicon chemically bonded to said titanium, forming a first layer comprising titanium-silicide; silicon cohesively bonded to said titanium-silicide, forming a second layer comprising silicon; carbon chemically bonded to said silicon, forming a third layer comprising silicon carbide; and carbon cohesively bonded to said silicon carbide, forming a fourth layer comprising diamond-like carbon. - View Dependent Claims (16, 17, 18)
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19. A solid substrate comprising titanium coated with diamond-like carbon by a process comprising:
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exposing said substrate to a vacuum at a pressure of about 10-5 torr or less; heating said substrate to between at least about 600°
C.-650°
C. (1112°
F.-1202°
F.);depositing silicon onto said substrate in an amount sufficient to form an inner bonding layer of titanium-silicide cohesively bonded to an outer layer of silicon; substantially simultaneous with said depositing of silicon, bombarding said deposited silicon with a first energetic beam of ions at a first energy, a first ion density, and for a first amount of time sufficient to form said inner titanium-silicide bonding layer cohesively bonded to said outer layer of silicon; condensing a diamond-like carbon precursor onto said outer layer of silicon at a second temperature and for a second amount of time sufficient to form a film of precursor molecules on said outer layer of silicon, wherein said second temperature is sufficiently low that said diamond-like carbon precursor is not vaporized off of said substrate; substantially simultaneous with said condensing of a diamond-like carbon precursor, bombarding said diamond-like carbon precursor with a second energetic beam of ions at a second energy, a second ion density, and for a third amount of time sufficient to form an inner silicon carbide layer cohesively bonded to an outer coating of diamond-like carbon. - View Dependent Claims (20, 21, 22, 23, 24, 25)
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Specification