1, Benefits: The mechanical action of ultrasound can soften tissues, enhance penetration, improve metabolism, promote blood circulation, and stimulate nervous system and cell functions. It can make the PH value of tissues develop to alkalinity. Relieve local acidosis related to inflammation. Ultrasound can affect blood flow, produce inflammation, inhibit and play an anti-inflammatory role. Make white blood cells move and promote angiogenesis.
2. Disadvantages: Pulsed ultrasonic waves will cause bubbles to contract, expand and even explode violently when propagating in the liquid containing micron bubbles. This phenomenon is called "cavitation", and the cells near the explosion bubble will be damaged.
Second, infrasound waves
1, benefits: infrasound is helpful to eliminate the tension of patients undergoing epidural anesthesia; Infrasound vibration changes the electrical characteristics of neuron membrane, and then changes the transmission times of nerve impulses in the nerve circulation circuit, and then changes the frequency of nerve activity from thalamus to cerebral cortex circulation circuit, which can produce hypnosis.
2. Disadvantages: When infrasound is the same as the natural frequency of organs, it will cause * * * vibration. For example, infrasound of 1-3Hz can make people feel scared. When the frequency of infrasound is close to the natural frequency of human brain (8- 12Hz), it will cause * * vibration, stimulate human brain, and have a certain impact on people's psychology and consciousness. In light cases, people feel uncomfortable, lack of concentration, poor memory and poor thinking.
Extended data:
Use of ultrasound:
1, ultrasonic holographic image: In the medical field, ultrasonic waves are often used to see through the human body and form two-dimensional images. Now this technology is being further improved, and two-dimensional images will become three-dimensional holographic images.
2. "Sightseeing" glasses: Another huge use of ultrasound is to let the blind "see the light again". This draws lessons from the principle of echolocation of bats. When bats fly, they don't catch their prey by visual exploration, on the contrary, they rely on their ears.
3. Traction beam
Powerful ultrasonic waves can suspend objects on the ground. Experiments show that as long as there is enough energy, objects can be lifted by ultrasonic waves and moved in different directions. This is very similar to the tractor beam that appears in many science fiction movies.
4. Efficient drill bit: Ultrasonic wave can also be used for geological exploration. High-power ultrasonic vibration energy is strong, which can effectively compress extruded substances. In geological exploration, it can be used as a "drill bit", just like a real drill bit, to squeeze a passage underground.
Baidu encyclopedia-ultrasound
Baidu encyclopedia-infrasound