Method and apparatus for treating surfaces with a plasma generated by electron cyclotron resonance
OwnerWard Dean Halversoninventor
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Abstract
The present invention provides methods and apparatus for plasma treatment of tubing surfaces. In one aspect, the invention provides a method for treating a tubing surface which calls for generating a gaseous plasma within a spatially localized region of space by electron cyclotron resonance (ECR), and exposing the surface to this plasma for a selected time period to treat the surface. Subsequent to the plasma treatment, the treated surface can be optionally coated with a selected compound, such as a bioactive material, e.g., anti-biotic or anti-coagulants.
Claims48
A method of treating a surface of tubular article, the method comprising the steps of:
- generating a gaseous plasma within a spatially-localized region of space by electron cyclotron resonance, and
- exposing at least a portion of a surface of the tubular article to said plasma for a selected time period to treat the surface.
A method of treating a wall of a lumen, comprising the steps of:
- placing a selected portion of said lumen in a treatment zone,
- applying a magnetic field having a selected strength to the treatment zone,
- introducing a gas into said lumen within said selected portion, said gas being in contact with the wall of said selected portion and having a selected partial pressure,
- irradiating said gas with electromagnetic radiation having a frequency selected to be substantially equal to electron cyclotron frequency at said selected magnetic field strength so as to ionize said gas and create a plasma zone within said selected portion, said plasma treating said wall of the lumen.
An apparatus for treating a surface of a tubular article, comprising
- a magnet for producing a static magnetic field within a region of space, said magnetic field having a selected amplitude,
- a conduit adapted to couple to a source of gas to deliver a selected quantity of gas into at least a portion of said region of space in which the surface to be treated is placed, and
- an electromagnetic-energy generator positioned so as to irradiate said region of space with electromagnetic radiation having a frequency substantially equal to an electron cyclotron frequency at said magnetic field magnitude so as to ionize said gas and create a plasma, said plasma treating the surface of the lumen.
An apparatus for treating a surface of a tubular article, comprising:
- a magnet for producing a static magnetic field within a selected region of space forming a treatment zone, said magnetic field having a selected amplitude,
- a waveguide section configured for connection to a source of microwave radiation, said waveguide section having two windows forming, in combination with the wall of the waveguide, an enclosure for storing a gas within the treatment zone, said windows being substantially transparent to the microwave radiation such that said source provides electromagnetic radiation within said enclosure having a selected frequency,
- at least one port for allowing insertion of a portion of the tubular article into said gas enclosure,
- wherein said radiation has a frequency substantially equal to electron resonance frequency at said selected amplitude of the magnetic field to ionize said gas and create a discharge within the treatment zone, said plasma being in contact with a selected surface of the tubular article to treat said surface.
Dependencies are inferred from the claim text.