Implantable wireless sensor for in vivo pressure measurement

1 . A sensor comprising:

a capacitor;

a three-dimensional inductor coil connected to said capacitor to form an LC circuit; and

an electrically insulating housing hermetically encapsulating said LC circuit;

wherein an electrical characteristic of said LC circuit is responsive to a change in an environmental parameter.

2 . The sensor of claim 1 , wherein the capacitor comprises at least two conductive elements disposed in opposed spaced apart relation.

3 . The sensor of claim 2 , wherein the conductive elements are conductive plates.

4 . The sensor of claim 2 , wherein the opposed conductive elements are spaced apart by less than 100 micrometers.

5 . The sensor of claim 2 , wherein the opposed conductive elements are spaced apart by less than 10 micrometers.

6 . The sensor of claim 2 , wherein the opposed conductive elements are spaced apart by less than 2 micrometers.

7 . The sensor of claim 1 , wherein said coil is self-supporting.

8 . The sensor of claim 1 , wherein said coil is supported on a bobbin.

9 . The sensor of claim 1 , wherein said coil is made using solid wire.

10 . The sensor of claim 1 , wherein said coil is made of individually insulated stands of wire twisted together to form a wire bundle.

11 . The sensor of claim 1 , wherein said coil may have circular or oblong or any other arbitrary cross-sectional configuration perpendicular to the central, magnetic axis of the coil.

12 . The sensor of claim 1 , wherein the electrically insulating housing is comprised of a material selected from the group consisting of fused silica, glass, sapphire, quartz, and diamond.

13 . The sensor of claim 1 , wherein the electrically insulating housing is substantially impervious to the passage of atoms and molecules.

14 . The sensor of claim 1 , wherein said housing is made of a material which elicits a medically acceptable level of biological reaction.

14 . The sensor of claim 1 , wherein said housing comprises a deflectable region.

15 . The sensor of claim 14 , wherein said deflectable region comprises said housing having a portion of reduced thickness.

16 . The sensor of claim 14 , wherein at least one of said capacitive elements is mechanically coupled to said deflectable region of said housing.

17 . The sensor of claim 14 , wherein said deflectable region is formed integrally with said housing.

18 . The sensor of claim 1 , further comprising means operatively associated with said housing for stabilizing said sensor with respect to a location within the body of a patient.

19 . The sensor of claim 18 , wherein said means operatively associated with said housing for stabilizing said sensor with respect to a location within the body of a patient comprises a spiral fastener for screwing the sensor into a wall of an organ.

20 . The sensor of claim 18 , wherein said means operatively associated with said housing for stabilizing said sensor with respect to a location within the body of a patient comprises a barb for anchoring the sensor into a wall of an organ.

21 . The sensor of claim 18 , wherein said means operatively associated with said housing for stabilizing said sensor with respect to a location within the body of a patient comprises a hook for anchoring the sensor into a wall of an organ.

22 . The sensor of claim 18 , wherein said means operatively associated with said housing for stabilizing said sensor with respect to a location within the body of a patient comprises an interference member extending outward from said body for engaging the walls of a lumen within which said body is located.

23 . The sensor of claim 1 , wherein said sensor is sized to fit through a catheter having an inner diameter of 5 millimeters.

24 . The sensor of claim 1 , wherein said sensor is sized to fit through a catheter having an inner diameter of 1 millimeter.