Development of a new HotBalloon TM ablation catheter equipped with a balloon surface temperature monitoring sensor for pulmonary vein isolation.

The balloon surface temperature (BST) should be monitored to ensure the success of the ablation procedure using the HotBalloon ablation catheter (HBC) in clinical settings. Therefore, we sought to develop a new HBC equipped with a surface temperature monitoring sensor. The BST was evaluated using a pseudo-tissue model and a thermocouple to imitate catheter insertion into the pulmonary vein. Thermo-fluid analysis with computer-aided engineering (CAE) was performed to analyse the temperature distribution in the catheter and the balloon. The CAE analysis reproduced the results from a pseudo-tissue model experiment and demonstrated that some fluid zones inside the catheter shaft had a nearly identical temperature as the BST during the liquid suction period. The pseudo-tissue model experiment confirmed that the temperature was almost the same between the balloon surface and the position of 5 mm inside the catheter shaft from the proximal end of the balloon. A thermocouple placed at 5 mm or 25 mm from the proximal end of the balloon within the catheter shaft showed an equivalent temperature result. This 5-25-mm distance is acceptable to set the BST monitoring sensor inside the catheter shaft, since the sensor can help accurately estimate the BST.