Patent ID: 8668686
Filing Date: 2014-03-11
Classification: A61B

Abstract:
1. A medical apparatus, comprising: an insertion tube having a distal portion; at least one ablation electrode disposed on the distal portion for conveying electromagnetic energy to a target tissue during an ablation procedure; accessory ports for delivering coolant to the ablation electrode at a low coolant flow and a high coolant flow; a first temperature sensor disposed on the distal portion sufficiently proximate the ablation electrode to detect heat generated in the target tissue during the ablation procedure; a second temperature sensor disposed on the distal portion sufficiently spaced apart from the ablation electrode to be relatively less responsive to the heat from the ablation than the first temperature sensor; and electronic logic circuitry linked to the first temperature sensor and the second temperature sensor wherein the electronic logic circuitry is programmed to compute a first temperature reading based on the respective temperatures sensed by the first temperature sensor and the second temperature sensor when the ablation electrode is cooled by the high flow of coolant and a second temperature reading based on the respective temperatures sensed by the first temperature sensor and the second temperature sensor when the ablation electrode is cooled by the low flow of coolant, wherein the electronic logic circuitry is programmed to indicate an unsatisfactory contact status between the ablation electrode and the target tissue when a difference between the first temperature reading and the second temperature reading fails to exceed a predetermined threshold.