Ultrasonic wave itself is not harmful to human body.
Ultrasonic waves can be used in medicine, military, industry, agriculture and so on
About ultrasonic waves
①Ultrasonic waves are a kind of frequency higher than 20,000 hertz sound waves, its directionality is good, the reflective ability is strong, easy to get a more concentrated acoustic energy, the propagation of the water in the distance is far, it can be used for distance measurement, speed measurement, cleaning, Welding, stone crushing, sterilization and disinfection.
②In medicine, military, industry, agriculture, there are many applications. Ultrasound is named for its lower frequency limit is greater than the upper limit of human hearing.
③Scientists will be the number of vibrations per second called the frequency of sound, which is measured in hertz (Hz). Our human ears can hear the frequency of sound waves for 20Hz-20,000Hz. therefore, we will be higher than 20,000 Hz frequency of sound waves called "ultrasound". The frequency of ultrasound waves usually used for medical diagnosis is 1 MHz-30 MHz.
4 The biological effect of ultrasound on the human body is related to the ultrasound power and exposure time.
⑤Low-power ultrasound, with limited exposure time, does not produce significant biological effects. Although high-intensity ultrasound (>?;5W/cm2) is used to crush stones and destroy tumor tissues with a strong mechanical power effect, diagnostic ultrasound is only using ultrasound as -? -kind of signal requires very little power.
Expanded:
1, ultrasonic wavelength is shorter than the general acoustic wave, has a better directionality, and can pass through the opaque material, this characteristic has been widely used in ultrasonic flaw detection This characteristic has been widely used in ultrasonic flaw detection, thickness measurement, distance measurement, remote control and ultrasonic imaging technology.
2, ultrasound imaging is the use of ultrasound to present the internal image of opaque material technology. The ultrasonic waves from the transducer through the acoustic lens focused on the opaque specimen, the ultrasonic waves transmitted from the specimen carries the information of the part being illuminated (such as the reflection of sound waves, absorption and scattering ability), through the acoustic lens convergence in the piezoelectric receiver, the resulting electrical signal into the amplifier, the use of scanning systems can be the opaque specimens the image of the fluorescent screen.
3, with the development of science and technology, medical technology advances, traditional surgery has experienced one advance after another. From open surgery to laparoscopic surgery, the development of today's surgical procedures have been realized without incisions and scars, outside the body to the body surgery, which is China's own research and development of focused ultrasound surgery.
4, then, focused ultrasound surgery will not bring some harm to patients? With this question, people.com.cn interviewed Wang Zhibiao, professor of biomedical engineering at Chongqing Medical University, director of the National Engineering Research Center of Ultrasound Medicine, and China's chief science communication expert, and Wang Lian, member of China's chief science communication expert group, and medical expert and chief physician of the National Engineering Research Center of Ultrasound Medicine.
5, ultrasound, CT, magnetic **** vibration, PET can allow people to see outside the body in vivo, more clear than open surgery, we can now even do 3D organ reconstruction, these are the use of ultrasound or X-ray penetration of the human body, these are not harmful to the human body, the principle of focused ultrasound surgery is the same as these, is also the use of ultrasound through the human body, the same human body no harm. harm."
Source Baidu Encyclopedia