An ultrasonic transducer focusing ultrasound into a thin waveguide by two elliptical reflectors

A high-power ultrasonic transducer for minimally invasive treatments is proposed, capable of treating areas inaccessible by high-intensity focused ultrasound treatments. This transducer employs two elliptical reflectors that efficiently focus ultrasound waves into a thin waveguide by utilizing mode conversion. Additionally, a slit structure is introduced to suppress wave diffraction, further enhancing the focusing capabilities of the transducer. Finite element analysis demonstrates that the proposed transducer achieves an impressive energy density magnification factor of 325, with an energy efficiency of 24.2 $ \% .$ This efficiency is 3.4 times higher than that of a conventional transducer, Double Parabolic refLector wave-guided Ultrasonic transducer.