Strain sensing system

• US 20040011137A1
• Filed: 07/10/2003
• Published: 01/22/2004
• Est. Priority Date: 07/10/2002
• Status: Abandoned Application

• Current Assignee: OrthoData Technologies, LLC
• Original Assignee: OrthoData Technologies, LLC
• Inventors: Naber, John F., Walsh, Kevin M., Hnat, William P.
• Application Number:
  US10/616,599
• Publication Number:
  US 20040011137A1
• Time in Patent Office: Days
• US Class Current: 73/789
• CPC Class Codes: A61B 17/7002 Longitudinal elements, e.g. rods
• 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 2562/043 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: 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 strain in an element comprising:

a sensor for measuring strain in said element producing an electrical signal representative thereof;

a telemetry circuit electrically coupled to said sensor for encoding and transmitting the signal representative of strain; and

a reader module remotely located from said sensor and said telemetry circuit for receiving the signal representative of strain.

2. A system for measuring and remotely monitoring strain in an element as claimed in claim 1 further comprising;

a housing for encapsulating said sensor and said telemetry circuit.

3. A system for measuring and remotely monitoring strain in an element as claimed in claim 2 wherein said housing is comprised of bio-compatible material capable of implantation in a living organism.

4. A system for measuring and remotely monitoring strain in an element as claimed in claim 1 wherein said sensor for measuring strain is a capacitive sensor.

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

6. The system for measuring and remotely monitoring strain in an element as claimed in claim 1 wherein said sensor for measuring strain is a surface acoustic wave sensor.

7. The system for measuring and remotely monitoring strain in an element as claimed in claim 1 wherein said sensor for measuring strain is a miniaturized strain gauge.

8. The system for measuring and remotely monitoring strain in an element as claimed in claim 3 wherein said housing is substantially annular for placement around an orthopedic implant rod.

9. The system for measuring and remotely monitoring strain in an element as claimed in claim 1 wherein said reader module further comprises a concomitant removable memory card for storing sensor data.

10. The system for measuring and remotely monitoring strain in an element as claimed in claim 9 wherein said reader module is battery powered.

11. A system for measuring and remotely monitoring strain in an element comprising:

a sensor for measuring static and dynamic strain in said element producing an electrical signal representative thereof;

a telemetry circuit electrically coupled to said sensor for encoding and transmitting the signal representative of strain;

a reader module remotely located from said sensor and said telemetry circuit for receiving the signal representative of strain and for transmitting power to said telemetry circuit; and

a control module in communication with said reader module for storing and processing the signal representative of strain.

12. The system for measuring and remotely monitoring strain in an element as claimed in claim 11 wherein said sensor for measuring strain is a capacitance sensor.

13. The system for measuring and remotely monitoring strain in an element as claimed in claim 11 wherein said sensor for measuring strain is a cantilever beam type capacitive sensor.

14. The system for measuring and remotely monitoring strain in an element as claimed in claim 11 further comprising:

a bio-compatible housing for encapsulating said sensor and said telemetry circuit.

15. The system for measuring and remotely monitoring strain in an element as claimed in claim 14 wherein said housing is substantially annular for placement around an orthopedic implant rod.

16. The system for measuring and remotely monitoring strain in an element as claimed in claim 14 wherein said sensor is secured to said housing and wherein the strain in said element is transmitted to said sensor through said housing.

17. The system for measuring and remotely monitoring strain in an element as claimed in claim 15 wherein said sensor is secured to said housing and wherein the strain in said element is transmitted to said sensor through said housing.