Invasive therapeutic probe
First Claim
1. An invasive probe assembly for therapeutic treatment, the probe assembly comprising:
- a coaxial feed line having an inner conductor, an outer conductor, and an insulating sleeve axially surrounding the outer conductor, the feed line configured for electrical contact to an RF source configured to provide RF energy having selected characteristics including a prescribed operating frequency; and
a probe having a rigid probe shaft and an antenna positioned therein, the antenna including a first dipole region at a distal end of the probe shaft and connected to the inner conductor of the feed line, the first dipole region having a rounded metallic tip, a second dipole region proximally spaced therefrom, forming a dipole axis, the second dipole region having a radiating skirt electricalliy connected at a distal end to the outer conductor of the feed line and therefrom axially spaced from the outer conductor to a proximal end the skirt, and a cylindrical insulator disposed between the outer conductor and the skirt, thereby forming a choke at the prescribed operating frequency;
wherein the length of the choke is substantially a quarter wavelength as determined for propagation of the provided energy through the cylindrical insulator, and a structural spacer formed of dielectric material disposed between the dipole regions along the dipole axis.
1 Assignment
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Accused Products
Abstract
An invasive therapeutic probe assembly and related methods for application of RF energy to a volume of body tissue are provided. The probe assembly includes an RF source configured to provide an RF energy having selected characteristics, a probe having a probe shaft and an antenna positioned therein, and a feed line for providing conductivity from the RF source to the antenna probe. The probe assembly is adapted to generate a zone of therapeutic effectiveness having a selected geometry and volume. The related method includes positioning the probe in a selected location with reference to a target tissue, initiating an electromagnetic field from the antenna having a selected geometry, and producing a zone of therapeutic effectiveness having a selected geometry and volume. The producing step preferably includes, taking periodic temperature measurements from sensors positioned at a selected location, and manipulating the selected characteristics of the RF energy to include duration and/or power level.
127 Citations
23 Claims
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1. An invasive probe assembly for therapeutic treatment, the probe assembly comprising:
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a coaxial feed line having an inner conductor, an outer conductor, and an insulating sleeve axially surrounding the outer conductor, the feed line configured for electrical contact to an RF source configured to provide RF energy having selected characteristics including a prescribed operating frequency; and
a probe having a rigid probe shaft and an antenna positioned therein, the antenna including a first dipole region at a distal end of the probe shaft and connected to the inner conductor of the feed line, the first dipole region having a rounded metallic tip, a second dipole region proximally spaced therefrom, forming a dipole axis, the second dipole region having a radiating skirt electricalliy connected at a distal end to the outer conductor of the feed line and therefrom axially spaced from the outer conductor to a proximal end the skirt, and a cylindrical insulator disposed between the outer conductor and the skirt, thereby forming a choke at the prescribed operating frequency;
wherein the length of the choke is substantially a quarter wavelength as determined for propagation of the provided energy through the cylindrical insulator, anda structural spacer formed of dielectric material disposed between the dipole regions along the dipole axis. - View Dependent Claims (2, 3, 4, 5, 6)
the insulating sleeve of the feed line terminates prior to the cylindrical insulator, and the metallic coating is further disposed in an axial bore defined by the cylindrical insulator.
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4. An invasive probe assembly as defined in claim 1, wherein the dielectric spacer is formed of polycarbonate and defines an axial bore sized to allow the inner conductor to extend therethrough.
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5. An invasive probe assembly as defined in claim 1, wherein the cylindrical insulator has a dielectric constant between about 9 and 10 and the prescribed operating frequency is about 2.45 GHz.
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6. An invasive probe assembly as defined in claim 5, wherein the choke has a length of about 1 cm.
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7. An invasive probe assembly for therapeutic treatment, the probe assembly comprising:
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a coaxial feed line having an inner conductor, an outer conductor and an insulating sleeve axially surrounding the outer conductor, the feed line configured for electrical contact to an RF source configured to provide RF energy having selected characteristics including a prescribed operating frequency; and
a probe having a rigid probe shaft with an antenna positioned therein, the antenna including, a first dipole region located at a distal end of the probe shaft and connected to the inner conductor of the feed line, a second dipole region proximally spaced therefrom, forming a dipole axis, the second dipole region having a radiating skirt electrically connected at a distal end to the outer conductor of the feed line and therefrom axially spaced from the outer conductor to a proximal end the skirt, and a cylindrical insulator disposed between the outer conductor and the skirt, thereby forming a choke at the prescribed operating frequency;
wherein the length of the choke is substantially a quarter wavelength as determined for propagation of the provided energy through the cylindrical insulator, anda structural spacer formed of dielectric material disposed between the dipole regions along the dipole axis, the spacer defining an axial bore allowing the inner conductor to extend therethrough. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
the insulating sleeve of the feed line terminates prior to the cylindrical insulator, and the metallic coating is disposed in an axial bore defined by the cylindrical insulator.
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16. An invasive probe assembly as defined in claim 7, wherein the cylindrical insulator is formed of ceramic.
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17. An invasive probe assembly as defined in claim 16, wherein the choke has a length of about 1 cm.
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18. A method of heating body tissue, the method comprising:
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positioning a probe in a selected location with reference to a target tissue, the probe having an antenna therein that receives RF energy from an RF source, the antenna including first and second dipole regions forming a dipole axis and a structural spacer formed of dielectric material disposed between the dipole regions along the dipole axis;
wherein the first dipole region has a rounded metallic tip, a second dipole region has a radiating skirt and a cylindrical insulator thereby forming a choke having a length substantially a quarter wavelength as determined for propagation of the provided energy through the cylindrical insulator;
initiating an electric field from the antenna having a selected geometry; and
producing a zone of therapeutic effectiveness having a selected geometry and volume.- View Dependent Claims (19)
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20. A method of making an invasive probe having a dipole antenna and a feed line adapted to connect the dipole antenna to an RF source, the method comprising:
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providing a first dipole region formed of an insulator having a cylindrical shape with a predetermined thickness and length, and having a conductive material coated thereon such that the insulator is substantially covered with conductive material and the proximal end of the insulator is void of conductive material;
fitting the coated insulator at a selected location along the feed line such that it is in contact with an outer conductor of the feed line thereby forming a choke;
placing a structural spacer of dielectric material forward of the first dipole region such that an inner connector of the feed extends through an axial bore thereof; and
placing a second dipole region forward of the structural spacer and in electrical contact with the inner conductor. - View Dependent Claims (21, 22, 23)
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Specification