Non-invasive tissue erosion by high intensity focused ultrasound

• Main Author: Muhammad Asyraf Zainol
• Other Authors: Zhou Yufeng
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/76424
• Institution: Nanyang Technological University

High Intensity Focused Ultrasound (HIFU) is a therapeutic modality which involves the use of ultrasound waves for medical purposes such as tissue ablation. The principle in which it works is that low powered beams are focused and converge to a single focal point at a targeted region to deliver high energy by superposition in the form of heat or mechanical agitation. This brings about thermal and mechanical ablation of varying effects, based on pre-determined parameters. The theoretical principles behind the aspects that made up HIFU treatment are understood and covered. At the same time, other non-invasive imaging techniques are examined in order be able to visualise the thermal erosion caused within the soft tissue or gel phantom that has been treated with HIFU. Through this means, we aim to understand better how different parameters affect the kind of thermal lesion formed; be it thermal or mechanical effects being more predominant and try to recognise and control this varying effects. Quantifying what is seen and deriving a conclusion is experimentally done, aided with the use of open source software available in documenting multi-dimensional imaging files. It is found that high pulse repetition frequency does not necessarily mean better erosion effects and that ablation time and duty cycle play crucial role when subjecting specimen to HIFU.