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:: Section 5
How does it work?A typical SVN is powered by a high-pressure stream of gas directed through an orifice (the jet). When the gas stream exits the orifice, the high speed jet produces low lateral pressure at the outlet that draws the liquid up the capillary tube and into the gas stream. The high shear force and turbulence there shatters the liquid into droplets. The primary spray produces a polydisperse aerosol with droplets ranging from 0.1 to 500 µm. The primary spray is directed against one or more baffles. Large droplets impact on the baffle surface and fall back to the medication reservoir to be nebulized again. This process decreases the MMAD and GSD of the output aerosol. A sphere or plate placed in line with the jet flow can serve as a baffle, as can the internal walls of the nebulizer. The fine aerosol can exit from the top or side of the SVN. The outlet is connected to a mouthpiece so that the patient can use it directly.
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