Patent ID: 8366633

Claim:
An implantable biometric sensor system comprising: a rigid case for subcutaneous implantation; an access portal to an internal fluid in the rigid case; a dual frequency crystal oscillator, affixed to the rigid case and configured to be in ducted communication with the internal fluid, for sensing a pressure difference in the internal fluid; at least one driver coil in electrical communication with the dual frequency crystal oscillator; the dual frequency crystal oscillator comprising: a cylindrical crystal, having an exterior surface and an interior surface, supported centrally by the subcutaneous case; a first metalized cylinder adjacent the exterior surface; a second metalized cylinder adjacent the exterior surface; a third metalized cylinder adjacent the interior surface; a first inductive coil supported by the subcutaneous case electrically connected to the first metalized cylinder and the third metalized cylinder; and a second inductive coil supported by the subcutaneous case electrically connected to the second metalized cylinder and the third metalized cylinder.