Introduction Of Ultrasonic Knife Method

High intensity focused ultrasound tumor ablation machine (HIFU, commonly known as ultrasonic knife) is a thermal therapy method that can induce coagulation necrosis of tumor tissue in vitro. It focuses the ultrasonic energy in one point, so that the temperature of the tissue at the focal point rises abruptly (65 ° C - 100 ° C), destroys the tumor tissue through high temperature, and can achieve the purpose of killing tumor cells, while the surrounding normal tissue is not affected.
High intensity focused ultrasound technology is an ultrasonic surgical treatment technology that arose in the 1940s. Through a certain focusing method, the ultrasonic energy emitted by the ultrasound is focused on the human tissue, forming a region with high sound intensity in the tissue -- the focal region, so that the temperature of the tissue reaches more than 65 ° C within 0.5 to 1 second. These tissue cells coagulate and necrosis without damaging the normal tissues outside the focal region, so as to carry out tumor treatment. This non-invasive treatment avoids the toxic side effects of radiotherapy and chemotherapy and the problem of radioactive accumulation, and can avoid the pain and injury of surgery, especially for deep tumor lesions and patients who are not suitable for surgery.
The ultrasonic wave emitted by the ultrasonic knife comes from the ultrasonic transducer, which is usually made of piezoelectric ceramic PZT sheet, and the high-frequency alternating voltage is added to it to drive the transducer to produce high-frequency mechanical vibration.
In order to improve the effect and accuracy of heating, the self-focusing method of piezoelectric crystal chip is used. Based on the self-focusing of a single transducer, six transducers are aligned to a focus in a certain geometric arrangement to achieve secondary focusing, also known as double focusing. The advantage of this design is that the energy at the focus can be maximum and the energy carried by the skin is minimum.