Embodiments provide devices, systems and methods for preventing deep vein (DV) thrombosis (DVT). One embodiment provides a DVT prevention device including a cuff that fits over a patient's knee, an applanator coupled to an inside cuff surface, an expandable member (EM) coupled to the applanator, a pressure source fluidically coupled to the EM and a controller for controlling EM inflation. When the EM is inflated, it applies a force to the applanator which is transmitted to the knee back surface causing a popliteal vein (PV) under the cuff to be compressed so as to increase backpressure behind the compressed PV and subsequently increase the velocity of blood flow in the leg DVs when the EM is deflated. The EM can be inflated in a cycle including pulsed inflation, inflation hold and relaxation. The cycles can be repeated and adjusted to achieve a desired increase of blood flow/velocity in leg DVs.