Methods and Apparatus for Utilizing Impeller-Based Rotationally-Scanning Catheters

An ablation catheter comprising:

• a tubular catheter body comprising:
• a lumen;
• a tip portion;
• a liquid inlet;
• at least one liquid outlet;
• and
• a liquid flow path defined between the liquid inlet and the liquid outlet;
• an ablation element mounted on the tip portion of the catheter body;
• and
• a rotationally-scanning ultrasound assembly disposed within the lumen of the catheter body adjacent the tip portion, the rotationally-scanning ultrasound assembly comprising:
• an ultrasound transducer having an active face;
• an acoustic mirror acoustically coupled to the active face of the ultrasound transducer;
• and
• an impeller positioned in the liquid flow path and operably coupled to at least one of the ultrasound transducer and the acoustic mirror to impart rotational motion thereto when a liquid flows through the impeller.

A method of assessing tissue, comprising:

• providing a catheter comprising:
• a tubular catheter body having a tip portion, an ablation element mounted on the tip portion, and a lumen;
• a rotationally-scanning ultrasound assembly disposed within the lumen adjacent the tip portion and including an ultrasound transducer having an active face, wherein the ultrasound assembly provides a visualization field adjacent the tip portion of the catheter body;
• and
• an impeller operably coupled to the ultrasound assembly to impart rotational motion thereto;
• placing the tip portion of the catheter adjacent tissue to be assessed;
• and
• flowing a liquid through the impeller, thereby rotating the ultrasound assembly.

A method of manufacturing an ablation catheter, comprising:

• providing a tubular catheter body having a tip portion and a lumen;
• mounting an ablation element on the tip portion;
• placing a rotationally-scanning ultrasound assembly within the lumen adjacent the tip portion, the ultrasound assembly including a transducer;
• and
• operably coupling an impeller to the ultrasound assembly to impart rotational motion to the ultrasound assembly when a liquid flows through the impeller.