Recent works on focused ultrasound (FUS) have shown great promise for cancer therapy. Researchers are continuously trying to improve system performance, which is resulting in an increased complexity that is more apparent when using multi-element phased array systems. This has led to significant efforts to reduce system size and cost by relying on system integration. Although ideas from other fields such as microwave antenna phased arrays can be adopted in FUS, the application requirements differ significantly since the frequency range used in FUS is much lower. In this paper, we review recent efforts to design efficient power monitoring, phase shifting and output driving techniques used specifically for high intensity focused ultrasound (HIFU).
Keywords: beam-steering; focused ultrasound; high-intensity focused ultrasound; hyperthermia; integrated circuits; noninvasive surgery; phase shifter; phased arrays; phased-locked loop; power amplifier; pulser; tissue ablation.