US Patent 8241242 Phacoaspiration flow restrictor with bypass tube

A device for achieving high vacuum stability during phacoemulsification surgery includes a main aspiration line connected to a vacuum source which enables a fluid flow from a phacoemulsification handpiece tip to a drainage reservoir. A first tubing segment is provided in the main aspiration line along with a second tubing segment generally parallel to the first tubing section and a valve disposed in the second tubing segment regulates fluid flow through the second tubing segment in order to limit vacuum surge in the main aspiration line upon clearing of an occlusion in the phacoemulsification handpiece tip.