Devices, systems, and methods for controlled volume ablation

A catheter for controlled volume ablation, comprising:

• an elongated member having a distal end and extending along a longitudinal axis;
• a first electrode extending along the elongated member, the first electrode having a plurality of distal portions each arranged as a circumferential band on a circumferential surface about the longitudinal axis on the distal end of the elongated member;
• a second electrode extending along the elongated member, the second electrode having a plurality of distal portions each arranged as a circumferential band on the circumferential surface about the longitudinal axis at the distal end of the elongated member such that the portions of the second electrode alternate with the portions of the first electrode along the longitudinal axis, the first and second electrodes creating a first ablation volume when activated while exposed to surrounding tissue;
• and
• a sheath slidably disposed about the elongated member, the sheath configured to change position by sliding along the member to, during an ablation procedure, insulate a portion of the first electrode and a portion of the second electrode from a surrounding tissue while selectively exposing a portion of the first electrode and a portion of the second electrode to the surrounding tissue, the exposed portions of the first and second electrodes creating a second ablation volume when activated that is less than the first ablation volume.