The extracorporeal lithotriptic machine is mainly composed of (1) extracorporeal shock wave generator; (2) shock wave triggering system; (3) shock wave coupling with the human body; (4) stone localization system; (5) computer-controlled operating system; and (6) treatment bed. The source of shock wave generation is the heart part of the extracorporeal shock wave lithotripter.
(1)Liquid electric shockwave generator is invented by German Dornier company and first applied to the shockwave generator, its technology is mature and reliable, it is most of the extracorporeal shockwave generator, the extracorporeal shockwave lithotriptic machine with this generator are; Germany Dornier company's Doner, the United States of America Medstone International company's Medstone, The SD series of France Northyate Rrseareh Company and various models of extracorporeal shock wave lithotripter developed and produced by our country. The starting point is that the electrodes are frequently replaced, generally the electrodes have to be replaced once for treating a patient. Another point is that the electrode tip has loss in the discharge process, which increases the distance between the tips and causes the focus to drift. The advantages are, mature technology, safety and reliability, high energy, especially suitable for the treatment of large stones and kidney staghorn stones. Because the shock wave generation is explosive, not only the noise, but also the high voltage current to the patient's heart caused some danger, must be used cardiac R-wave triggering to ensure the safety of the patient in the treatment process.
(2) electromagnetic shock wave generator; the principle of its generation is a high-voltage coil generates a pulsed magnetic field to promote the metal diaphragm in the water vibration generates shock waves. Electromagnetic shock wave source focus pressure is low, about half of the liquid electric type, focal zone is long, the second spot pulse time is longer than the liquid electric, waveform is poor, low frequency components, so the number of lithotripsy increased, the efficiency is poor, and the human body tissue damage surface is large, and the advantages of the spot is stable, not easy to shift, no need to replace the electrodes, but the price of the generator is high and have to be fixed times to replace. There is no danger to the patient's heart, and it is generally triggered by breathing, and when there is a special medical need, it can also be triggered by electrocardiographic R-wave without noise. The shock wave generator is invented by Germany Siemens and the University of Metz cooperation research. Compact of Dawney, Lithostar extracorporeal shockwave lithotripter of Siemens all use electromagnetic shockwave generation source.
(3) liquid electric compound pulse wave source; its principle is a high-voltage discharge in the water at a time, at a specific time in the generation of double pulse shock wave (can produce cavitation effect of double pulse). Liquid electric compound pulse source a discharge in the vs produce 2 pulses, with liquid electric single pulse waveform performance to take full advantage of the role of cavitation effect. The so-called cavitation effect is a certain amount of electricity shock wave vibration in the water, so that the gas dissolved in the water is released, the gas in the shock wave movement within a very short period of time expansion, collapse, this phenomenon is called cavitation effect. The first shock wave around the stone, and the internal production of a large number of microscopic cells, so that the bubble from the production to the expansion of the rupture generally only takes a few vs or so, in the first shock wave produced by the highest end of the bubble, to the second shock wave, exacerbating the expansion of the bubble rupture. This increases the pressure and tension on the stone, improves the lithotripsy effect, and shortens the treatment time and reduces soft tissue scratches. According to reports, compound pulses can increase the stone crushing effect by 40%, and the damage is also relatively reduced. The compound pulse source is the development direction of extracorporeal shock wave lithotripter.