A spherical high intensity focused ultrasound phased array with unequal space between elements

Here we provided a new spherical HIFU (High intensity Focused Ultrasound) phased array with unequal center-to-center space between elements that was proved can lower the grating-lobe. Even with 4λ element space, the grating lobe was still below -20 dB. With optimization calculation we found that with 231 circular elements of 1 cm diameter and at 0.5 WHz application frequency, the array could form a high intensity focus of 800 W/cm² in a 2 cm underside radius cylinder area at 10~15 cm depth. And it also could accomplish accomplish-focus for realizing ultrasound hyperthermia to large humor.