Portable and tunable continuous wave driver from 1 MHz to 10 MHz for HIFU transducers

High Intensity Focused Ultrasound (HIFU) is a non-invasive technique used for oncology treatment, by causing tumor ablation. This paper presents the construction of a portable and tunable continuous wave driver to excite HIFU transducers. Driver consists of a frequency generator with adjustable resolution (10 kHz or 100 kHz increments) and 50Ω output impedance, a radiofrequency amplifier and a 1.965 MHz HIFU transducer. System characterization (frequency measurements, HIFU transducer electrical/acoustical characterization and amplifier power response) and ablation experiments in tissue mimicking phantoms are presented in this paper. HIFU transducer was driven with a 6.76 W continuous wave, during 3 min, which was gradually risen up to 50.118 W. The result at 52 s is a visible lesion inside the phantom. The lesion has a cigar shape at the focus distance (17 mm). Temperature at the focus reached 98.3°C.