Quantitative measurement of acoustic radiation force on a thin catheter for use in endovascular therapy

In this study, the quantitative measurement of acoustic radiation force acting on a thin catheter has been carried out to develop endovascular therapy with microbubbles. First, it is elucidated that the force acting on a thin catheter made of perfluoroalkoxy (PFA) copolymer can be obtained from the cantilever equation in the effective range, where the displacement of the catheter divided by the cube of the length of the catheter is less than 1.0 × 10 −5 mm −2 . Next, on the basis of the cantilever theory, the force acting on the catheter (diameter 400 µm, material PFA) is measured to be 24 µN under the continuous ultrasound (frequency 2 MHz, sound pressure 300 kPa) irradiation. Furthermore, it is observed that the force depends on the ultrasound frequency. Finally, we conclude that the force is obtained under practical conditions for the realization of endovascular therapy and suggest that thin catheter navigation using ultrasound is fully promising.