Fecha de publicación: 06/08/2015 Fuente: WIPO "pollen" A breast pump system includes a vacuum break backflow preventer for preventing breast milk from accidentally backflowing into a suction tube leading to a vacuum pump. The backflow preventer is a vacuum passageway with two spaced apart suction openings. The two openings convey air to cyclically pressurize and depressurize a small milk charging chamber. If milk accidentally covers one of the openings, air at the other opening minimizes the pressure differential that might otherwise draw the milk deep into the suction tube and toward the vacuum pump. For ease of cleaning and sanitizing, the system avoids or minimizes the use of baffles, permanently enclosed passageways, moving parts, and tight inside corners. Some passageways can be split open for access during cleaning. To make the breast milk collection device less protruding under a brassier, the vacuum passageway curves around the side of a nipple receptacle rather than in front of it.