Flutter Valve. The flutter valve is a small hand-held device that looks like a pipe. It contains a steel ball that sits in a small plastic cone. The patient inhales deeply, holding the breath for two to three seconds. As the patient exhales (keeping the cheeks in), the ball is pushed up toward the top of the device and then falls back down. About 10 to 50 vibrations per second are generated and transmitted to the lungs to help loosen secretions. This is repeated for up to 15 breath cycles. The patient coughs at the end.
http://www.umm.edu/patiented/articles/how_chronic_obstructiv...

Клапан с шариком, размещенный на вершине трубки, препятствует проникновению в нее воды во время ныряния.
http://www.dive.ru/reference/article.php?uid=25025




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Note added at 22 mins (2004-01-18 12:19:48 GMT)
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или шариковый клапан