Devices and methods for delivering energy to body lumens

A medical device for delivering energy to a body lumen, the device comprising:

• an elongate member having a proximal end, a distal end, and a lumen extending therebetween;
• and
• a basket assembly disposed at or adjacent the distal end and configured to transition between a collapsed state and an expanded state, wherein the basket assembly includes a plurality of expandable legs, wherein a first expandable leg of the plurality of expandable legs includes a first region disposed at or adjacent a proximal portion of the first expandable leg, a second region disposed distally of the first region, an active region disposed distally of the second region, a third region disposed distally of the active region, and a fourth region disposed distally of the third region, wherein the first expandable leg is pre-shaped such that in the collapsed state and while the basket assembly is unconstrained by an outer sheath:
• the second region extends distally and radially outward from the first region,
• the active region extends distally from (i) the second region in a radially inward curve toward a longitudinal axis of the medical device and toward a radially innermost point, and (ii) the radially innermost point in a radially outward curve toward the third region, and
• the third region extends distally from the active region and radially inward toward the fourth region;
• wherein the active region is configured to contact and deliver energy to the body lumen when the basket assembly is in the expanded state, and
• when the basket assembly is in the expanded state, distal ends of the plurality of expandable legs converge toward one another.