Sensing module having a piezo-resistive sensor for orthopedic load sensing insert device

• US 8,689,647 B2
• Filed: 07/01/2012
• Issued: 04/08/2014
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: OrthoSensor, Inc (Stryker Corporation)
• Inventors: Stein, Marc
• Primary Examiner(s): Noori, Max
• Application Number:
  US13/539,476
• Publication Number:
  US 20120283600A1
• Time in Patent Office: 646 Days
• Field of Search: 737/60, 737/77, 738/626.36
• US Class Current: 73/862.636
• CPC Class Codes: A61B 5/4509 Bone density determination
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61B 5/6878 Bone
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61B 8/15 Transmission-tomography

Abstract

A sensing insert device (100) is disclosed for measuring a parameter of the muscular-skeletal system. The sensing insert device (100) can be temporary or permanent. Used intra-operatively, the sensing insert device (100) comprises an insert dock (202) and a sensing module (200). The sensing module (200) is a self-contained encapsulated measurement device having at least one contacting surface that couples to the muscular-skeletal system. The sensing module (200) comprises one or more sensing assemblages, electronic circuitry (307), an antenna (2302), and communication circuitry (320). The sensing assemblages are between a top plate (1502) and a bottom plate (1504) in a sensing platform (121). The sensing assemblages comprise a load disc (2004) and a piezo-resistive sensor (2002) to measure the parameter. An elastic support structure or springs (1108) is coupled between the top plate (1502) and the bottom plate (1504) to prevent cantilevering of a surface.

Claims

1. A sensing module for measuring a force, pressure, or load applied by the muscular-skeletal system comprising:

a first surface for coupling to the muscular-skeletal system where the first surface includes a predetermined area comprising a polygon;

a second surface; and

at least three force sensors coupled between the first and second surfaces where each sensor underlies a vertex of the polygon, where the sensing module is configured to measure the force, pressure, or load applied by the muscular-skeletal system, and where the sensing module is configured to identify a position of applied load on the first surface.

2. The sensing module of claim 1 further including:

electronic circuitry coupled to the at least three force sensors;

a transmitter coupled to the electronic circuitry configured to transmit sensor data; and

a power source configured to power the electronic circuitry and transmitter.

3. The sensing module of claim 2 further includes an encapsulating enclosure to house the electronic circuitry, transmitter, power source, and the at least three force sensors.

4. The sensing module of claim 3 where the polygon is a triangle.

5. The sensing module of claim 4 further including a flexible interconnect coupling the electronic circuitry to the at least three force sensors.

6. The sensing module of claim 5 further including a remote system configured to receive and display data from the sensing module.

7. The sensing module of claim further including a structure configured to distribute loading applied to the first surface to the at least three force sensors.

8. The sensing module of claim 7 where the first surface is configured to move under a force.

9. The sensing module of claim 8 were the at least three force sensors are plezo-resistive sensors.

10. The sensing module of claim where the electronic circuitry underlies the at least three force sensors.

11. A sensing module for measuring a force, pressure, or load applied by the muscular-skeletal system comprising:

a first surface for coupling to the muscular-skeletal system where the first surface includes a predetermined area comprising a polygon;

a second surface;

at least three force sensors coupled between the first and second surfaces where each sensor underlies a vertex of the polygon, where the sensing module is configured to measure a force applied by the muscular-skeletal system to the first surface, and where the sensing module is configured to identify a position of applied load on the first surface; and

at least one structure to distribute loading coupled between the first surface and the at least three force.

12. The sensing module of claim 11 where the sensing module is configured to measure a force applied by the muscular-skeletal system within the predetermined area and where the sensing module is configured to identify the position of applied load within the predetermined area.

13. The sensing module of claim 12 where the polygon is a triangle.

14. The sensing module of claim 13 where the sensing module is an insert prosthetic component further comprising;

electronic circuitry coupled to the at least three force sensors;

a transmitter coupled to the electronic circuitry configured to transmit sensor data; and

a power source configured to power the electronic circuitry and transmitter.

15. The sensing module of claim 14 where the electronic circuitry, transmitter, power source, and at least three force sensors are housed in the insert prosthetic component and isolated from an external environment.

16. The sensing module of claim 15 where the first surface is an articular surface.

17. The sensing module of claim 16 where the sensing module is configured to send data such that the force and position of applied load is displayed on a remote system in real time and where the at least three force sensors comprises one of a piezo-resistive sensor, MEMS sensor, strain gauge, or mechanical sensor.

18. A sensing module for measuring a force applied by the muscular-skeletal system comprising:

a first surface for coupling to the muscular-skeletal system where the first surface includes a predetermined area comprising a polygon;

a second surface; and

at least three piezo-resistive sensors coupled between the first and second surfaces where each sensor underlies a vertex of the polygon, where the sensing module is configured to measure the force applied by the muscular-skeletal system, and where the sensing module is configured to identify a position of applied load on the first surface.

19. The sensing module of claim 18 where the sensing module is configured to measure a force applied by the muscular-skeletal system within the predetermined area and where the sensing module is configured to identify the position of applied load within the predetermined area.

20. The sensing module of claim 19 where at least one structure to distribute loading is coupled between the first surface and the at least three piezo-resistive sensors.