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 living being. The system includes an implantable sensor (20) unit and an associated externally located energy application transceiver (24). The sensor unit is in the form of a housing (28) including a movable deflection member (76) and a tuned circuit (22) including an inductor coil (L) and a capacitor (C). The housing 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. The deflection member extends through a slot (78) in the wall portion of the housing for engagement with only the flattened portion of the blood vessel to move in response to the pressure applied to the flattened portion of the blood vessel by the blood. The deflection member includes a ferrite core (74). The ferrite core is arranged to move with respect to the coil (70) in response to the movement of the deflection member, thereby changing the inductance of the tuned circuit. Electrical energy is provided from the transceiver unit to energize the tuned circuit of the sensor unit, which when energized provides a wireless electrical output signal representative of pressure changes within the blood vessel back to the transceiver. Since the deflection member only engages the flattened portion of the blood vessel the electrical output signal is linear with respect to blood pressure.