Abstract: The present tool and associated methods provide for precisely controlled positioning of an ablative element, or an array of ablative elements, against a tissue targeted for treatment. Such treatment is in the form of a lesion, caused by energy emitted from the ablative element, selectively changing or destroying cells within the target tissue. The tool incorporates an element array. This element array consists of one or more energy emitting (ablative) elements. The energy delivered may be in the form of radio frequency, microwave, ultrasound, light, and cryogenics, among others. The element array may also incorporate one or more temperature sensing elements. Further, this element array may incorporate a fluid system providing recirculative cooling or fluid delivery to cool the element array and/or surrounding tissue. In one use of the tool, the element array, which is located at the distal end of an elongate member, is positioned against cardiac tissue during an open heart procedure.