高强度聚焦超声作用下体模组织温度上升研究

为研究高强度聚焦超声(HIFU)作用下组织温度上升规律,建立了高强度聚焦声场和组织温度场有限元仿真模型,并通过体外辐照实验对仿真模型进行了验证。通过仿真对水和组织域中的聚焦声场进行建模,计算吸收声能并将其用作热源以计算组织内的温升。进一步制备仿生物组织凝胶体模,利用热电偶进行HIFU作用下体模组织焦点处的测温。结果表明:该模型可有效预测HIFU治疗时的温度上升,与实验所得温度误差不超过 3℃;体模组织受到超声辐照时温度会立即升高,起初温升速率较快,随着辐照时间延长,温升速率逐渐降低,停止辐照后温度立即下降。

The Temperature Rise of Tissue-Mimicking Phantom under the Action of High Intensity Focused Ultrasound

In order to research the rule of tissue temperature rise under the action of high-intensity focused ultrasound (HIFU), a finite element simulation model of high-intensity focused acoustic field and tissue temperature field is established, and the simulation model is verified by in vitro irradiation experiments. The focused acoustic field in the water and tissue domain is modeled by simulation, and the absorbed acoustic energy is calculated and used as a heat source to calculate the temperature rise within the tissue. By preparing a biological tissue gel phantom, thermocouples are used to measure the temperature at the focal point of the phantom tissue under the action of HIFU. The results show that the model can effectively predict the temperature rise during HIFU treatment, and the difference between the temperature obtained in the experiment is not more than 3℃; the temperature of the phantom tissue will rise immediately when the phantom tissue is irradiated by ultrasound, and the temperature rise rate is faster at first, as the time increases, the temperature rise rate gradually decreases, and the temperature drops immediately after the irradiation is stopped.