1. An implantable medical lead, comprising:
a lead body including a proximal section and a distal section; and
at least one electrode coupled to the distal section of the lead body, the at least one electrode comprising a conductor mass having an asymmetrically distributed current density.
2. The implantable medical lead of claim 1, wherein the electrode includes an active electrode portion and an inactive electrode portion, and wherein the conductor mass on the active electrode portion has a current density greater than the conductor mass of the inactive electrode portion.
3. The implantable medical lead of claim 2, wherein the electrode comprises an annular-shaped electrode including a first semi-circular section and a second semi-circular section, the first and second semi-circular sections separated from each other via a centerline of the electrode perpendicular to a longitudinal axis of the lead body.
4. The implantable medical lead of claim 2, wherein a centroid of the electrode is offset from the centerline of the electrode towards the second semi-circular section.
5. The implantable medical lead of claim 4, wherein a thickness of the second semi-circular section is greater than a thickness of the first semi-circular section.
6. The implantable medical lead of claim 4, wherein the electrode is coupled to a conductor cable or conductor coil disposed within the lead body, and wherein the connection of the electrode to the conductor cable or conductor coil is at or near the second semi-circular portion.
7. The implantable medical lead of claim 6, wherein the electrode is coupled to the conductor cable or conductor coil via a tubular member coupled to an interior portion of the second semi-circular section.
8. The implantable medical lead of claim 6, wherein the electrode is coupled to an inwardly extending portion of the second semi-circular section.
9. The implantable medical lead of claim 2, wherein the electrode comprises:
an outer conductor body; and
an inner conductor body coupled to the outer conductor body.
10. The implantable medical lead of claim 9, wherein the inner conductor body includes a first section and a second section, the first and second sections separated from each other via a centerline of the electrode perpendicular to a longitudinal axis of the lead body.
11. The implantable medical lead of claim 10, wherein a centroid of the inner conductor body is offset from the centerline of the electrode towards the second section of the inner conductor body.
12. The implantable medical lead of claim 2, wherein the electrode includes a ring-shaped electrode having a windowed section.
13. The implantable medical lead of claim 12, wherein the ring-shaped electrode includes at least one insulative layer coupled to the inactive electrode portion.
14. The implantable medical lead of claim 2, wherein the at least one electrode includes a semi-annular electrode having an exterior facing section and an interior facing section, the interior facing section of the electrode including an insulative layer.
15. The implantable medical lead of claim 2, wherein the at least one electrode includes a plurality of electrodes each having an asymmetrically distributed current density.
16. The implantable medical lead of claim 15, wherein the active electrode portions of each electrode are circumferentially offset from each other along the length of the lead body.
17. An implantable medical lead, comprising:
a lead body including a proximal section and a distal section, the distal section of the lead body having a pre-biased shape configured to secure the lead to an inner wall of a body vessel; and
a plurality of electrodes coupled to and spaced apart along the distal section of the lead body, each electrode having an asymmetrically distributed current density configured to impart a directionality to an active portion of the electrode that contacts the inner wall.
18. A method for imparting current density directionality within an implantable lead electrode, the method comprising:
determining a target region within the body for implanting an implantable lead;
selecting a lead shape suitable for implantation at the target region; and
optimizing the current density distribution within an electrode of the implantable lead to impart a directionality at one or more active portions of the electrode configured to contact body tissue at the target region.
19. The method of claim 18, wherein optimizing the current density distribution within the electrode includes asymmetrically mass loading the electrode towards the one or more active portions.
20. The method of claim 18, wherein optimizing the current density distribution within the electrode includes altering the surface geometry of the electrode.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A mounting table structure including an electrostatic chuck at a central region thereof and a base member that mounts thereon a focus ring along a periphery of the electrostatic chuck, the mounting table structure comprising:
a sheet, having elasticity and thermal conductivity, provided between the focus ring and the base member;
a pressing member provided along a periphery of the focus ring, and configured to press the focus ring toward the base member to contract the sheet; and
a supporting member connected to the base member,
wherein the pressing member includes a pressing surface that presses the focus ring toward the base member and a plurality of contact surfaces that face downward and are arranged at a predetermined interval in a circumferential direction thereof,
the supporting member includes first contact surfaces and second contact surfaces,
the first contact surfaces are arranged at the predetermined interval in the circumferential direction,
the second contact surfaces are arranged at the predetermined interval in the circumferential direction such that the second contact surfaces and the first contact surfaces are alternately arranged,
the first contact surfaces are located at a position different from that of the second contact surfaces in a height direction,
the contact surfaces of the pressing member are protruded from portions of the pressing member at a distance larger than distances of the first contact surfaces and the second contact surfaces in the height direction, and
a thickness decrement of the sheet is set by contacting the pressing member with the supporting member.
2. The mounting table structure of claim 1,
wherein the supporting member further includes third contact surfaces,
the third contact surfaces are arranged at the predetermined interval in the circumferential direction and are located at a position different from those of the first contact surfaces and the second contact surfaces in the height direction, and
the contact surfaces of the pressing member are protruded from the portions of the pressing member at a distance larger than distances of the first contact surfaces, the second contact surfaces and the third contact surfaces in the height direction.
3. The mount table structure of claim 1,
wherein the supporting member and the base member serve as a single body.
4. A method of holding a focus ring in a mounting table structure including an electrostatic chuck at a central region thereof and a base member that mounts thereon a focus ring, the method comprising:
mounting the focus ring along a periphery of the electrostatic chuck such that a sheet having elasticity and thermal conductivity is provided between the base member and the focus ring;
adjusting a distance between a pressing surface of a pressing member contacted to the focus ring and the base member in a height direction by determining a position in the height direction where the pressing member comes into contact with a supporting member connected to the base member by selecting a position of the pressing member on the supporting member in a circumferential direction; and
fastening the pressing member to the supporting member while the pressing member is in contact with the supporting member at the determined position in the height direction.
5. The method of claim 4,
wherein, in the adjusting of the distance between the pressing surface of the pressing member and the base member in the height direction, the position in the height direction where the pressing member comes into contact with the supporting member is determined such that a decrement of a thickness of the sheet falls within a range from about 10% to about 20% of the thickness of the sheet.