Bidirectional Soft Robotic Catheter for Arrhythmia Treatment

Heart rhythm disorders are becoming increasingly prevalent with population aging. Atrial fibrillation ablation (AFA) is a procedure used to treat an irregular heart rhythm (arrhythmia) that starts in the heart's upper chambers. The AFA works by scarring or destroying heart tissue to disrupt aberrant conduction pathways causing the arrhythmia. In hospital cardiac units, a flexible catheter with integrated metal electrode is currently used for the AFA procedure. Despite advances, existing cardiac catheter tips are driven by cable mechanisms which are associated with high nonlinear hysteresis and force loss. In addition, they are also limited to rigid components which require multiple actuators to control the bending tip to reach the complex anatomical corners of the heart. This paper introduces a new soft hydraulic catheter that can achieve bidirectional bending motion via a single soft artificial muscle. The new catheter is also equipped with a portable handle as an ergonomic control interface. To validate the design concept, various prototypes are fabricated and tested including bending angles and generated force capability. Mathematical models for the bending arm are also developed and experimentally validated. The new soft catheter will enable rapid and precise manipulation to reach any target within the cardiac chambers, offering more rapid and focused ablation therapy to improve patient outcomes.