Principle of Ultrasound Transmission Gel

Ultrasound examination is currently the most widely used clinical screening or examination method. When the patient comes to the ultrasound department of the hospital for the ultrasound examination, the examination site is always coated with a light blue or transparent gel. For the sonographer, this gel is an important tool for ultrasound examination to be carried out smoothly, it is really ordinary, but to patients is quite strange. Next, the instant hand sanitizer gel manufacturer introduces you to ultrasonic gel.

First, let's understand why ultrasound is used for this gel. Those who have studied physics should know that when ultrasonic waves hit the interface of two different media, reflections will occur, resulting in less energy for the ultrasonic waves entering the other medium. The degree of reflection of ultrasonic waves is related to a certain index of the two media. 

Ultrasound Gel

This index is the acoustic impedance. Acoustic impedance indicates the ability of a medium to hinder the propagation of ultrasonic waves. Of course, different media will have different acoustic impedances. From a physical point of view, the greater the difference in acoustic impedance between the two media, the more reflections. Therefore, in the ultrasound examination, if the ultrasound probe is in direct contact with the skin, there must be an air-filled cavity between the two, which is equivalent to forming an interface between the ultrasound probe and the air. 

Due to the large difference in acoustic impedance, when When the ultrasonic wave emitted by the ultrasonic probe travels to the air interface, it will have a strong reflection effect, so that the ultrasonic wave basically cannot enter the body of the human body, and cannot achieve the purpose of diagnostic examination or treatment.

Ultrasound Gel

Therefore, according to this physical principle, there is an urgent need for a substance that can be filled between the surface of the ultrasound probe and the surface of the skin to eliminate the interference of air, so that the ultrasound can pass through smoothly, and the loss of sound waves is minimized to maximize the entry in the human body, this substance is the medical ultrasound transmission gel commonly used by ultrasound doctors before ultrasound examination. Of course, in addition to such an important role, the ultrasound gel has another role. 

The ultrasound gel also acts as a lubricant. Otherwise, without it, the sonographer needs to spend more effort, and the patient's skin will be subjected to more friction damage. Through the analysis of the above physical principles, our requirements for ultrasonic coupling agents are also very simple: it is required to be approximately equal to the acoustic impedance of human tissue to reduce reflection losses; the attenuation coefficient should be small, and the attenuation loss of ultrasonic waves should be minimized; at the probe and skin surface It should be filled better to completely eliminate the air; it can be kept for a long time without drying and stickiness for a long time so that the probe can smoothly slide and scan; it does not irritate the skin and does not cause damage to the skin; it is easy to clean, etc.