SYSTEM INCLUDING AN IMPLANTABLE DEVICE AND METHODS OF USE FOR DETERMINING BLOOD PRESSURE AND OTHER BLOOD PARAMETERS OF A LIVING BEING

摘要

A system for monitoring blood pressure within a blood vessel (12) of a livingbeing. The system includes an implantable sensor (20) unit and an associatedexternally located energy application transceiver (24). The sensor unit is inthe form of a housing (28) including a movable deflection member (76) and atuned circuit (22) including an inductor coil (L) and a capacitor (C). Thehousing surrounds the wall of the blood vessel and includes a wall portion(42) arranged to flatten a portion of the periphery of the blood vessel. Thedeflection member extends through a slot (78) in the wall portion of thehousing for engagement with only the flattened portion of the blood vessel tomove in response to the pressure applied to the flattened portion of the bloodvessel by the blood. The deflection member includes a ferrite core (74). Theferrite core is arranged to move with respect to the coil (70) in response tothe movement of the deflection member, thereby changing the inductance of thetuned circuit. Electrical energy is provided from the transceiver unit toenergize the tuned circuit of the sensor unit, which when energized provides awireless electrical output signal representative of pressure changes withinthe blood vessel back to the transceiver. Since the deflection member onlyengages the flattened portion of the blood vessel the electrical output signalis linear with respect to blood pressure.