HIFU has been widely used to treat different types of tumors, including those of prostate, liver, breast, kidney, bone and pancreas because of its non-invasive and precise approach for tissue ablation. For successful HIFU operation, it is important to have a reliable guidance and treatment monitoring method such as ultrasound imaging. Most of ultrasound imaging-guided HIFU system are not compact, because it requires a cooling system for the transducer, and needs separate imaging and HIFU transducers. This is due to the properties of piezoelectric transducers such as self-heating. On the other hand, Capacitive Micromachined Ultrasonic Transducers (CMUTs) have a distinctive advantage over piezoelectric transducers in respect to self-heating mechanism and wide fractional bandwidth.
In this talk, I will present a compact dual-mode ultrasound system that can perform ultrasound imaging and HIFU using 2-D CMUT array. The probe is equipped with a dual-mode application-specific integrated circuit(ASIC) and a 32 x 32-element 2-D CMUT array. Both dual-mode ASIC and CMUT array are integrated to the probe with a flexible printed circuit board using flip-chip bonding. Also, I will talk about the new CMUT array design that can produce higher output pressure without device failure. With new CMUT array, the focused pressure at F-1 (8mm) was measured to 16.33 MPa peak-to-peak. An ablation test was successfully performed both on HIFU phantom gel and ex-vivo tissue. Lastly, I will show the demonstration of ultrasound imaging guided HIFU on ex-vivo tissue using dual-mode ultrasound system.
Ji Hoon Jang received B.S. degree in Electronic and Electrical Engineering at Pohang University of Science and Technology (POSTECH) and M.S. and Ph.D. degree both in Electrical Engineering at Stanford University. He is recipient of National Scholarship for Science and Engineering students, College Student Scholarship from Korea Fellowship for Advanced Studies, Top Undergraduate Student Scholarship from STX Scholarship Foundation, Undergraduate Scholarship from GE (Fullbright Scholarship), and Graduate Scholarship from STX Scholarship Foundation.