Abstract: The present invention provides a blood flow measurement device for implantation either within or around a blood vessel. The invention blood flow measurement device comprises a hollow tubular body, such as a stent, having a sensor with a resonant circuit for establishing an electrical current flowing within the blood vessel. Once implanted and activated by an external power source, the flow of current in the circuit generates an electromagnetic signal indicative of the rate of blood flow in the associated vessel. The signal can be picked up by an external monitor to display blood flow information. Since blood flow information is obtained non-invasively once the device is implanted, the device can be used to monitor blood flow in a patient undergoing strenuous exercise, after having been given an appropriate drug, and the like.