Methods and devices are provided for regulating a hydraulic restriction system including a restriction device. In general, the methods and devices can allow for non-invasive, transient pressure control. The methods and devices can also, in some embodiments, mechanically regulate pressure of the restriction...http://www.google.fr/patents/US8142452?utm_source=gb-gplus-shareBrevet US8142452 - Controlling pressure in adjustable restriction devices
Controlling pressure in adjustable restriction devices
