NSF/FDA SIR: Assessment of derating procedure using remote temperature measurements during HIFU sonication

1137166 banerjee高强度聚焦超声（high Intensity Focused Ultrasound， HIFU）是一种微创手术技术，在介入医学中具有潜力，应用于肿瘤和肌瘤消融、血管烧灼和凝块溶解。在HIFU设备的临床前监管审查中，设备的表征涉及多个评估，包括液体介质中强度场的处方，组织模拟材料或切除动物器官中温升和病变体积的测定，以及相对于所需目标的光束聚焦。在临床相关的功率水平下，由于光束对实验传感器的破坏潜力，以及传感器与光束干扰的可能性以及这些传感器引入潜在空化位点，HIFU光束的表征是困难的。对于高强度和高功率的HIFU设备，在液体介质中测量的声压是不能降低或降准的。估计组织介质中的压力。本研究的差距在于，尽管HIFU具有许多技术优势，但目前在美国市场上只有少数HIFU设备。阻碍HIFU设备更快进入市场的一个障碍是缺乏标准化和廉价的测试方法来确定设备的安全性和有效性。这反过来又使HIFU设备商业化的道路复杂化，从而限制了该设备在临床上的广泛使用。本研究的长期目标是改善HIFU换能器的特性。目的是测试一种非线性降额方法，以评估HIFU光束的热效应。中心假设是，从水中测量得到的降额压力可以确定温度和热剂量，以评估组织中的生物效应。

1137166BanerjeeHigh Intensity Focused Ultrasound (HIFU) is a minimally invasive surgical technique that has potential in interventional medicine, with applications that include tumor and fibroid ablation, vessel cauterization, and clot lyses. In the pre-clinical regulatory review of HIFU devices, characterization of devices involves multiple assessments, including prescription of the intensity field in a liquid me-dium, determination of temperature rise and lesion volume in a tissue-mimicking material or excised animal organ, and obtaining beam focus relative to the desired target. Characterization of HIFU beams is difficult at clinically relevant power levels due to the destructive potential of beams to expe-rimental sensors, as well as the possibility of interference of the sensors with the beam and the intro-duction of potential cavitation sites by these sensors. For higher intensities and powers, which are characteristics of HIFU devices, the acoustic pressure, measured in the liquid medium, can't be re-duced or ?derated? to estimate the pressure in a tissue medium. The gap in this research is that only a few HIFU devices are currently marketed in the US despite many technical advantages of HIFU. One obstacle impeding a faster path to market for HIFU devices is the lack of standardized and inex-pensive test methods for establishing the safety and efficacy of the devices. This, in turn, compli-cates the path to HIFU device commercialization, thereby limiting wider use of the devices clinically. The long-term goal of this research is to improve characterization of HIFU transducers. The ob-jective is to test a nonlinear derating method that can evaluate the thermal effects of HIFU beams. The central hypothesis is that the derated pressure, obtained from measurements in water, can deter-mine temperatures and thermal doses for assessing bioeffects in tissues.