Controllable expandable catheter

An electrophysiological catheter comprising:

• a handle comprising:
• a control mechanism that is housed inside of the handle;
• and
• a selective movement limiter, the selective movement limiter being slidably moveable along a longitudinal axis defined by the handle for selectively engaging the control mechanism;
• and
• a catheter shaft comprising a catheter shaft proximal end and a catheter shaft distal end, wherein the catheter shaft proximal end is coupled to the handle;
• an expandable structure comprising elongated splines and a distal hub, wherein each of the elongated splines comprises a shape memory material and a plurality of ring electrodes, wherein each of the elongated splines comprises a respective spline proximal end and a respective spline distal end, wherein each of the spline proximal ends is coupled to the catheter shaft distal end, and wherein each of the spline distal ends is coupled to the distal hub;
• and
• a deflection control member coupled to the distal hub, wherein the selective movement limiter coupled to the control mechanism selectively varies a position of the distal hub relative to the catheter shaft distal end to selectively vary an amount of expansion of the expandable structure, wherein a shape of the expandable structure is produced via a combination of the shape memory material and the position of the selective movement limiter, wherein the selective movement limiter limits a longitudinal movement of the deflection control member when the selective movement limiter is engaged with the control mechanism in a locked position, wherein the deflection control member moves freely along the longitudinal axis in an unlocked position.