An motorized pump is disclosed that includes a flexible diaphragm fitting within a rigid member, a motor drive mechanism for drawing a puller member attached to the diaphragm away from the rigid member to create a space between the diaphragm and the rigid member and form a negative pressure region...http://www.google.es/patents/US5776098?utm_source=gb-gplus-sharePatente US5776098 - Diaphragm pump and pump mounted in a carrying case useful in breast pumping
Diaphragm pump and pump mounted in a carrying case useful in breast pumping ...
