Multi-Functional Sensor Array on the Cryoablation Balloon for Atrial Fibrillation

A new treatment of cryoablation for atrial fibrillation shows advantages over traditional radiofrequency ablation, including lower re-ablation rate, fewer thrombus, higher efficiency, and increased safety. However, for the commercial cryoablation balloon, physical signs are monitored by an extra guide wire and thermocouples inside the cryoballoon, which is complex and results in errors. Here, we propose a stretchable and flexible array with electrodes and temperature sensors attached to the surface of the cryoballoon for in-situ cardiac electrocardiograph mapping and ablation feedback. The influence of inflation degrees, electrode size, and temperature on electrodes is investigated and the optimized diameter of electrodes is chosen as 400 mu m. The sensitivity, stability, repeatability, resolution, and response time of temperature sensors are tested, showing its ability of accurate monitoring. Furthermore, in-vitro experiments on a swine heart are performed. The proposed device attached to the cryoballoon contributes to the monitoring of the cryoablation process and feedback to the operator, simplifying the catheter and easing the interventional operation.