Investigation on Occlusion Effect of Tumor Vessel in HIFU Surgery

In this study, a thermal sensitive powder has been added to silicon based gel as raw material of vessel phantom for displaying the thermal dosage profile caused by high intensity focused ultrasound. A fused deposition modeling system has been used for fabricating the shell casting mold and the vessel arbor mold. The arbor prototype, made of wax, is solidified in the cavity of vessel arbor mold. The vessel phantom object embedded with the arbor prototype is created in the shell mold casting process. The vessel phantom is obtained by immersing the vessel phantom object into hot water (65c´ C) for melting the vessel arbor prototype. A high intensity focused ultrasound (HIFU) experiment is conducted for verifying the feasibility of displaying the thermal dosage profile of the fabricated vessel phantom. The HIFU experimental parameters including driving power ofHIFU transducer, ultrasound exposure duration and volume flow rate are used for investigating the thermal dosage variation by the perfusion of vessel phantom. The properties of fabricated mimicking phantom agree well with those of human tissue. The experimental results show that the proposed method can fabricate the Y-type vessel phantom. The proposed method has been proved as a promising fabrication process in fabricating the vessel phantom and it displays the thermal dosage profile in HIFU experiment.