Strain sensing system

• US 7,357,037 B2
• Filed: 09/14/2005
• Issued: 04/15/2008
• Est. Priority Date: 07/10/2002
• Status: Expired due to Term

• Current Assignee: Globus Medical, Inc.
• Original Assignee: OrthoData Technologies, LLC
• Inventors: Hnat, William P., Naber, John F., Walsh, Kevin M.
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US11/226,023
• Publication Number:
  US 20060032314A1
• Time in Patent Office: 944 Days
• Field of Search: 737/95
• US Class Current: 73/795
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/4504 Bones A61B5/4547 takes precedence
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: G01D 5/183 Sensing rotation or linear movement using strain, force or pressure sensors
• CPC Class Codes: G01D 9/005 Solid-state data loggers
• CPC Class Codes: G01L 1/142 using capacitors
• CPC Class Codes: G01L 1/165 with acoustic surface waves
• CPC Class Codes: G01L 1/22 using resistance strain gauges
• CPC Class Codes: G01L 1/225 Measuring circuits therefor
• CPC Class Codes: G01L 19/086 for remote indication

Abstract

The present invention provides a system 10 for measuring and remotely monitoring strain in an element 1 having a strain sensor 20, a telemetry circuit 40 for transmitting strain data to a remote location, and a reader module 60 for transmitting energy to the telemetry circuit and receiving said data.

Claims

1. A system for measuring and remotely monitoring the change in curvature in an element comprising:

a sensor for measuring the change in curvature in said element producing an electrical signal representative thereof;

a bio-compatible housing for encapsulating said sensor and contacting said element, whereby said housing transmits said change in curvature of said element to said sensor; and

a telemetry circuit electrically coupled to said sensor for encoding and transmitting the signal representative of said change in curvature.

2. A system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 1 further comprising:

a housing for encapsulating said sensor and said telemetry circuit having an interior surface for contacting said element whereby said housing transmits said change in curvature of said element to said sensor.

3. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 1 wherein said sensor for measuring change in curvature is a cantilever beam type capacitive sensor.

4. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 2 wherein said housing is substantially annular for placement around an orthopedic implant rod.

5. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 2 comprising:

a truncated annular housing having an interior surface that conforms closely to an exterior surface of said element whereby said change in curvature thereof is transmitted through said annular housing to said sensor.

6. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 5 comprising:

a truncated annular housing having side portions shaped to conform to an orthopedic implant exterior surface whereby said annular housing is pressure-fitted onto said implant.

7. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 6 wherein said orthopedic implant comprises a rod.

8. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 6 wherein said orthopedic implant comprises a plate.

9. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 6 wherein said orthopedic implant comprises a pedicle screw.

10. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 6 wherein said orthopedic implant comprises a joint implant.

11. The system for measuring and remotely monitoring the change in curvature in an element as claimed in claim 2 comprising:

a housing having a flat portion on an exterior surface thereof for mounting said sensor thereto.