The liquid applied during the ultrasound examination does not require a special bath and can be wiped with a paper towel. the liquid applied during the ultrasound examination is a medical coupling agent, which is a water-based polymer gel composed of medical products, which is characterized by a neutral pH value, non-toxic, tasteless, non-irritating and non-greasy, does not irritate the skin and does not damage clothing, and is non-corrosive and non-damaging to the ultrasound probe. now there are also ultrasound couplers on the market with disinfection Ultrasound couplant with sterilization function is now available on the market. Do ultrasound examination can not be separated from the coupling agent, its main functions are as follows: 1, to eliminate the air between the probe and the skin, in order to improve the clarity of the image display, if there is air between the probe and the skin, ultrasound encounters air will be total reflection and cause the attenuation of acoustic energy, affecting the clarity of the image. 2, to play the role of lubrication, can reduce the friction between the probe and the skin, so that the probe can be flexible The probe can be slid at will.