Vibration control of thin catheter in blood vessel using phase-sweeping of interference acoustic field

Catheters are widely used in diagnosis and minimally invasive treatments, and the demand for active control of thin catheters (<0.3 mm) is increasing. Although we previously achieved bending along and perpendicular to ultrasound propagation, there was a limitation in bending direction or opposing transducer arrangements. In this study, we used a phase sweeping in an interferential acoustic field to bend the catheter independent to the direction of propagation. We measured the displacement of the tip of the catheter under various ultrasound conditions including incident angles and sweeping times. As the result, we found that the maximum displacement and vibration period depended on the sweeping time, while the vibration amplitude is determined by the initial configuration. The obtained parameters are useful for controlling the thin catheter as the future intravascular applications.