A method of performing therapy on tissue using a medical apparatus. The apparatus includes a shaft configured for insertion into a hollow anatomical structure (HAS) and has a tissue sensor and a therapeutic energy application device both located on the shaft. The method comprises: receiving electrical power at a first power level and directing the first-level power to the tissue sensor and not to the therapeutic energy application device, thereby enabling tissue sensing with the tissue sensor; receiving electrical power at a second power level higher than the first-level power; and, in response to receipt of the second-level power, directing the second-level power to the therapeutic energy application device, thereby enabling performance of therapy on the tissue with the therapeutic energy application device. Additional methods and apparatus are disclosed as well.