System and method for delivering energy to tissue

A method for ablating tissue, said method comprising:

• providing an ablation system comprising an elongate shaft and an ablation element, the ablation element comprising an ultrasound transducer disposed within a housing coupled to a distal portion of the elongate shaft, wherein the housing comprises an open window, wherein the ultrasound transducer comprises a single ultrasound transducer element having an active portion and an inactive portion;
• positioning the ablation element adjacent a target tissue;
• delivering a collimated beam of ultrasound energy comprising ablation energy from the ultrasound transducer to the target tissue through the open window without contacting a zone of ablation with the elongate shaft or any structure disposed thereon;
• sensing a distance between the ultrasound transducer and the target tissue with the ultrasound transducer, or sensing properties of the target tissue with the ultrasound transducer, and
• ablating at least a portion of the target tissue with the beam of ultrasound energy comprising the ablation energy, thereby forming the zone of ablation comprising a continuous lesion in the target tissue.

A system for ablating tissue, said system comprising:

• an elongate shaft having a proximal portion, a movable distal portion, and a longitudinal axis;
• an ablation element comprising an ultrasound transducer disposed within a housing, the housing coupled to the movable distal portion of the elongate shaft, wherein the ultrasound transducer comprises a single ultrasound transducer element having an active portion and an inactive portion,
• wherein the ultrasound transducer is configured to sense a distance between the ultrasound transducer and a target tissue, or to sense properties of the target tissue,
• wherein the ultrasound transducer is configured to deliver a collimated beam of ultrasound energy comprising ablation energy to the target tissue without contacting a zone of ablation with the elongate shaft or any structure thereon, thereby ablating at least a portion of the target tissue.

A method for ablating tissue, said method comprising:

• providing an elongate shaft and an ablation element, the ablation element comprising an ultrasound transducer disposed within a housing coupled to a distal portion of the elongate shaft, wherein the ultrasound transducer comprises a single ultrasound transducer element having an active portion and an inactive portion;
• positioning the ablation element adjacent a target tissue;
• delivering a collimated beam of ultrasound energy comprising ablation energy from the ultrasound transducer to the target tissue without contacting a zone of ablation with the elongate shaft or any structure disposed thereon;
• sensing a distance between the ultrasound transducer and the target tissue with the ultrasound transducer;
• and or sensing properties of the target tissue with the ultrasound transducer
• ablating at least a portion of the target tissue with the beam of ultrasound energy comprising the ablation energy, thereby forming the zone of ablation comprising a continuous lesion in the target tissue.