Abstract: A system for monitoring the flow of blood within an endoluminal passage is provided comprising a medical device and a sensor. The medical device is implantable within the endoluminal passage and includes a shaft and an expandable segment coupled to the shaft. The expandable segment is movable between a first state and a second state. Movement of the expandable segment is responsive to a change in the fluid pressure external to the expandable segment. The sensor is positioned on the medical device and is adapted to collect information associated with the state of the expandable segment.