An ultrasonic nebulizer is a device that uses ultrasonic frequencies to turn a liquid medication into a fine mist so it can be inhaled. The ultrasonic frequencies are sound waves outside the range that can be heard by human ears. This type of nebulizer breaks the medicine up into particles and creates an aerosol, which is a mixture of air and ultra-fine particles that appear as a mist to the naked eye. As with all types of nebulizers, the goal is to get medication directly into the lungs.
The advantage of this type of nebulizer exists primarily in the particle size. The particles of aerosol may be much smaller than those created by compressor — or jet — nebulizers, which use a compressor to force air through a liquid and create a mist. An ultrasonic nebulizer's method of turning the liquid into a mist involves no direct force, so the particles must be smaller to be separated from the liquid than those created by a burst of air. In addition, because the frequency of the waves is always the same and the force of a compressor may vary, an ultrasonic nebulizer creates more consistent particles.
It has fewer and smaller parts, so an ultrasonic nebulizer is much smaller and weighs less than compressor nebulizers. Within this type of nebulizer, electricity from a small battery is used to create an ultrasonic wave, which vibrates an element in contact with the medicine. This element transfers the energy to the liquid and turns it into a vapor mist. Such a process requires very few parts and only minimal movement. This makes this nebulizer much more portable.
In some of the newer ultrasonic nebulizers, the energy is transferred to an extremely fine mesh created by using a laser to drill holes through a membrane. This mesh sits on top of the liquid, as opposed to the vibrating element in a normal ultrasonic nebulizer, which is at the bottom of the reservoir that holds the liquid. Under normal conditions, the mesh is too fine for the liquid to pass through. When the mesh is vibrated, the microscopic holes act as pumps, releasing uniform particles.
In addition to the size and weight differences, the fewer moving parts of these nebulizers make less noise than compressor nebulizers. As much as anything, this difference can be one of the most important to those who use these nebulizers. The reduced noise makes it possible to use the nebulizers without drawing as much attention. In addition, many activities, such as watching TV, with which a compressor nebulizer might interfere may be easier with an ultrasonic nebulizer.