Abstract: A device for expressing milk from one or more breasts has at least one, and preferably two expressers and a pump. The expressers each have a cup for fitting on the breasts and a cup outlet to which a vacuum created by the pump can be connected. The cups have a flexible liner which collapses around the breast to establish the vacuum. Pulsating pressure is applied to the outside of the liner to increase the vacuum and stimulate milk production. The pressure is applied through lines which are vented to maintain adequate, consistent pressure pulses without stalling the pump.

Abstract: Milk is extracted from a human breast by placing the breast in a cup having a vacuum port. The cup also has a flexible liner that allows vacuum to extract milk when the liner is in a first, open position, the milk being drawn into the vacuum port by the vacuum when the liner is in the first position. The liner also has a second position in which the nipple of the breast is compressed enough to substantially reduce the flow of milk from the breast. The liner is opened and closed in a pulsating manner at a predetermined pulsation rate. The user may select a pulsation ratio that produces acceptable milk transfer and comfort. Optimum pulsation ratios vary from user to user, but are generally between about 20% and about 80% for the vacuum portion of the pulsation cycle.