Fig. 4From: Low-frequency ultrasound for pulmonary hypertension therapyThe eigenmodes at the resonant frequencies: a for transducer with flat surface at frequencies of 28,44 kHz; b transducer with flat surface at frequency of 45,81 kHz; c transducer with cut-out surface at frequency of 28,13 kHz; d transducer with cut-out surface at frequency of 38,19 kHzBack to article page