What is extracorporeal shock wave lithotripsy?Extracorporeal shock wave lithotripsy (ESWL) is the use of shock waves produced by the impact
What is extracorporeal shock wave lithotripsy?
Extracorporeal shock wave lithotripsy (ESWL) is the use of shock waves produced by the impact of the impact of the crushing of the stones in the body, including the urinary system stone crushing, so that with the excretion of the body excreted (Figure 34, figure 35). The invention of extracorporeal shock wave lithotripsy (ESWL) is regarded as one of the three new medical technologies (CT, MRI, ESWL) in twentieth Century. This is the beginning of the birth of the technology in 1980s is known as the treatment of urinary stones on the revolution, has been recognized as the preferred treatment of urinary stones.
Figure 34 pattern of renal stone before and after lithotripsy
Figure 35 pattern of ureteral calculi before and after lithotripsy
There are several types of extracorporeal shock wave lithotripsy machine?
Lithotriptors all the two basic parts, the accurate positioning system of shock wave that can crush stones and stones, is the core of shock wave lithotripsy machine. In addition to electrohydraulic shock wave, electromagnetic waves, are piezoelectric shock wave source etc..
(1) liquid electric extracorporeal shock wave lithotripsy shock wave generator is a hollow metal semi ellipsoid reflector is full of water in a large stainless steel basin bottom, semi elliptical sphere of a built-in pole type electrode, electrode gap is exactly located at the first focus, when the discharge is shock wave spherical scattering to semi ellipsoid wall, which is reflected in the second focus focus reflectors (F2), the energy can be increased 200 ~ 300 times, can be placed in the crushed stones.
(2) electromagnetic extracorporeal shock wave lithotripsy and magnetic type of shock wave is first converted into electricity energy, and then converted into mechanical energy, the acoustic lens and the focusing incident (self focusing reflector) or mechanical wave after the formation of. The important characteristic of the electromagnetic shock wave is that the pulse discharge is stable, the waveform is almost the same, so the focus is relatively stable. In addition, shock wave can be used continuously, without frequent replacement of electrode. The emergence of electromagnetic shock wave is a great development of ESWL technology. At present, electromagnetic shock wave technology is becoming more and more mature,.
(3) piezoelectric extracorporeal shock wave lithotripsy is a kind of piezoelectric crystal electric energy and mechanical energy conversion material. Hundreds of pieces of piezoelectric element in a spherical disc are arranged, the spherical body is full of water. When the high frequency pulse current is applied to each piezoelectric element at the same time, because of the piezoelectric effect, each piezoelectric element generates a shock wave and points to the focus. Because of the focus area is very small, the gravel stone is from external layer erosion or spalling, the formation of small pieces of sand or powder and is easy to discharge. But its power is low, so the repetition rate is high and the treatment time is long.
Extracorporeal shock wave lithotripsy machine how to hit the body of stone?
ESWL positioning, is to use the relevant equipment to determine the location of the stone in the human body, and the stone accurately moved to the shock wave focal zone process. The positioning system is one of the key factors for the success of extracorporeal lithotripsy. At present, most of the stone crusher using X-ray surveillance system or B ultrasound system for positioning, these two methods have their own characteristics, but also complement each other.
Extracorporeal shock wave lithotripsy is harmful to the body?
Since its inception, ESWL has become the first choice for the treatment of urinary calculi because of its non-invasive, safe and efficient features. However, the shock wave itself has some damage to human tissues and organs, which may lead to a variety of damage, and produce a variety of adverse reactions. Therefore, it is very important to understand the biological effects of shock wave in order to develop and utilize ESWL.
The results of animal experiments and clinical studies have demonstrated that strict control of working voltage, each treatment interval of two times and the number of shock wave therapy in the treatment of ESWL, the basic kidney harmless, some minor damage will be restored.