Ultrasound and Magnetic Dual-Mode Stacked Transducer for Sonothrombolysis with a Combination of Nanodroplets and Magnetic Nanoparticles

It has been observed that ultrasound thrombolysis is more effective and safer than conventional techniques of thrombolysis, such as mechanical thrombectomy or pharmaceutical medication therapies. Recent work also reported that the dual-mode excitation combining magnetic field and ultrasound helped dramatically increase the thrombolysis rate. Therefore, in this work, based on the dual-mode concept, we demonstrated a 4-element stacked transducer with a center frequency of 450 kHz, which can create ultrasonic waves in addition to a high frequency oscillating magnetic field to activate the superparamagnetic iron oxide nanoparticles (SPIONs) and nanodroplets. Under 250 Vpp input voltage, the transducer reached a peak-negative pressure of 3 MPa. The transducer can simultaneously generate ultrasound cavitation and magnetic pulse excitation, thus providing higher thrombolysis efficiency.