SMALL FORM FACTOR MUSCULAR-SKELETAL PARAMETER MEASUREMENT SYSTEM

• US 20130079669A1
• Filed: 09/23/2011
• Published: 03/28/2013
• Est. Priority Date: 09/23/2011
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: OrthoSensor, Inc (Stryker Corporation)
• Inventors: Stein, Marc, Miller, Andrew P., Addink, Jason, Chase, Andrew U.
• Granted Patent: US 9,462,964 B2
• Time in Patent Office: Days
• US Class Current: 600/587
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: A61B 5/6878 Bone
• CPC Class Codes: A61B 5/6882 Anchoring means
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/3067 for data transfer
• CPC Class Codes: A61F 2002/3895 unicompartimental
• CPC Class Codes: A61F 2002/4666 for measuring force, pressure or mechanical tension

Abstract

At least one embodiment is directed to an insert for measuring a parameter of the muscular-skeletal system. The insert can be temporary or permanent. In one embodiment, the insert is prosthetic component for a single compartment of the knee. The insert comprises a support structure and a support structure respectively having an articular surface and a load bearing surface. The height of the insert is less than 10 millimeters. At least one internal cavity is formed when support structures are coupled together for housing electronic circuitry, sensors, and the power source. The cavity can be sterilized through a port. A membrane is between the port and the cavity. A sterilization gas permeates the membrane for sterilizing cavity. The membrane reduces the ingress of solids and liquids to the cavity.

Claims

1. A small form factor measurement system for measuring loading applied by a muscular-skeletal system comprising:

a housing that includes a plurality of sensors, electronic circuitry operatively coupled to the plurality of sensors, and a power source where the measurement system is less than 10 millimeters thick.

2. The measurement system of claim 1 where the measurement system is a prosthetic insert for a muscular-skeletal joint.

3. The measurement system of claim 1 where the measurement system is substantially dimensionally equal to a passive final insert for a uni-condylar application.

4. The measurement system of claim 1 where the housing comprises:

a first support structure having an articular surface; and

a second support structure having a load-bearing surface where the first and second structures form the housing that encloses the plurality of sensors, power source, and electronic circuitry.

5. The measurement system of claim 4 where a sensing assembly stack comprises:

a load plate coupled to the articular surface of the first support structure;

a sensor coupled to the load plate; and

a pad region coupled to the load-bearing surface of the second support structure where the pad region supports the sensor.

6. The measurement system of claim 5 where the load plate is triangular in shape and where a region corresponding to each vertex of the load plate has a sensor coupled thereto.

7. The measurement system of claim 6 where the electronic circuitry and power source underlie at least a portion of the load plate.

8. The measurement system of claim 4 where the articular surface of the first support structure comprises an ultra high molecular weight polyethylene material.

9. The measurement system of claim 4 where the first and second support structures comprise a polycarbonate material.

10. The measurement system of claim 4 where the articular surface flexes under loading.

11. The measurement system of claim 10 where the first support structure is grooved to allow flexing of the articular surface.

12. A uni-condylar knee insert for measuring loading applied by a muscular-skeletal system comprising:

a first support structure having an articular surface; and

a second support structure having a load bearing surface where the first and second structures are coupled together having at least one interior cavity with a combined thickness less than or equal to 10 millimeters.

13. The uni-condylar knee insert of claim 12 further including:

a plurality of sensors;

electronic circuitry operatively coupled to the sensors; and

a power source coupled to the electronic circuitry where the sensors, electronic circuitry, and power source are contained within the at least one interior cavity.

14. The uni-condylar knee insert of claim 13 further including a load plate coupled between the plurality of sensors and an interior surface of the first support structure.

15. The uni-condylar knee insert of claim 14 where the electronic circuitry and power source underlies at least a portion of the load plate.

16. The uni-condylar knee insert of claim 15 further including:

a printed circuit board having the electronic circuitry and power source mounted thereto where the printed circuit board is in the at least one cavity;

pad regions coupled to the load-bearing surface of the second support structure where each pad region is coupled to a sensor; and

an interconnect overlying the electronic circuitry coupled to each sensor where the interconnect couples to a connector on the printed circuit board.

17. The uni-condylar knee insert of claim 16 where peripheral interior surfaces of the first and second support structure mate together and where the first and second support structure are sealed to isolate the at least one cavity from an external environment.

18. A small form factor position and load measurement system for the muscular-skeletal system comprising:

a first support structure having a load-bearing surface and a plurality of pad regions at a predetermined height above the load-bearing surface;

a printed circuit board having electronic circuitry thereon; and

sensors coupled to the pad regions of the first support structure where the printed circuit board is placed in a cavity of the first support structure overlying the load-bearing surface such that the electronic circuitry and printed circuit board are below the sensors.

19. The system of claim 18 further including:

a planar interconnect overlying at least a portion of the printed circuit board where the planar interconnect couples to each sensor and where the planar interconnect flexibly couples to a connector coupled to the printed circuit board;

a load plate overlying at least a portion of the printed circuit board where the load plate couples to and distributes loading to each sensor and where the load plate is aligned to the first support structure with at least one alignment feature.

20. The system of claim 19 further including a second support structure having a load-bearing surface where the interior peripheral surfaces of the first and second support structures are coupled together to isolate the electronic circuitry and sensors from an external environment and where an internal surface of the second support structure couples to the load plate.