Orthopedic simulator with a multi-axis slide table assembly

• US 7,913,573 B2
• Filed: 01/05/2007
• Issued: 03/29/2011
• Est. Priority Date: 01/13/2006
• Status: Active Grant

• Current Assignee: MTS Systems Corporation (Illinois Tool Works Inc.)
• Original Assignee: MTS Systems Corporation (Illinois Tool Works Inc.)
• Inventors: Schulz, Bradley D., Fahrendorff, Harold F., Leska, Paul J. Sr., Willis, Dennis J.
• Primary Examiner(s): Caputo; Lisa M
• Assistant Examiner(s): DAVIS, OCTAVIA L
• Application Number:
  US11/649,962
• Publication Number:
  US 20070169572A1
• Time in Patent Office: 1,544 Days
• Field of Search: 737/98, 738/620.8, 737/94, 738/653, 738/56, 738/656
• US Class Current: 73/856
• CPC Class Codes: A61F 2002/7695 Means for testing non-implantable prostheses
• CPC Class Codes: G01N 2203/0025 Shearing
• CPC Class Codes: G01N 2203/0089 Biorheological properties
• CPC Class Codes: G01N 2203/0222 Temperature
• CPC Class Codes: G01N 2203/0242 With circulation of a fluid
• CPC Class Codes: G01N 2203/0246 Special simulation of "in situ" conditions, scale models or dummies
• CPC Class Codes: G01N 2203/0256 Triaxial, i.e. the forces being applied along three normal axes of the specimen
• CPC Class Codes: G01N 3/32 by applying repeated or pulsating forces
• CPC Class Codes: G01N 3/56 Investigating resistance to wear or abrasion

Abstract

An orthopedic simulator including a holder assembly and a slide table is disclosed. The holder assembly is configured to hold a test specimen to supply test loads. In the embodiment shown, the slide table is coupled to the holder assembly and includes a plurality of translation plates movable along a plurality of axis. As shown, the plurality of translation plates include a first translation plate movable along a first axis and a second translation plate movable along a second axis generally transverse to the first axis. In illustrated embodiments, an adjustable screw lock is configured to provide a positive lock to restrict movement or stroke of the first or second translation plates along the first or second axis. As disclosed, movement of the first or second translation plates is biased via a spring assembly for example to simulate the effect of soft tissue.

Claims

1. An orthopedic simulator comprising:

a holder assembly configured to hold a test specimen; and

a multi-axis slide table coupled to the holder assembly, the multi-axis slide table including;

a base;

a first translation plate mounted to the base through a first linear slide and rail arrangement and movable along a first axis;

a second translation plate mounted to the first translation plate through a second linear slide and rail arrangement and movable along a second axis different from the first axis; and

at least one post coupled to the base and having a screw slot configured to receive a lock screw and the lock screw being position in alignment with one of the first or second translation plates to provide a positive lock to limit movement of the one of the first or second translation plates.

2. The simulator of claim 1 comprising one or more springs configured to supply a force relative to at least one of the first or second translation plates to provide a load input to the test specimen.

3. The simulator of claim 2, comprising a plurality of springs to supply the force to each of the first and second translation plates along the first and second axes.

4. The simulator of claim 1 comprising one or more actuators coupled to at least one of the first or second translation plates that produce at least one of a static or dynamic shear force on the at least one of the first or second translation plates.

5. The simulator of claim 4, wherein the one or more actuators include at least one of an electric actuator, a pneumatic actuator or a servo-hydraulic actuator.

6. The simulator of claim 1, wherein the first and second linear slide and rail arrangements include double row/side roller bearings.

7. The simulator of claim 1, further comprising a soft tissue simulating arrangement coupled to the first and second translation plates.

8. The simulator assembly of claim 1, comprising a free-floating mode and a positive lock mode wherein in the positive lock mode the lock screw is aligned to limit movement of the one of the first or second translation plates.

9. The simulator of claim 1 comprising a plurality of posts spaced along at least one of the first or second axes and each of the plurality of posts configured to receive lock screws to provide the positive lock to limit movement of the one of the first or second translation plates along the first or second axis.

10. The simulator of claim 9 wherein the plurality of posts include first and second posts coupled to the base and configured to receive the lock screws to provide the positive lock to limit movement of the first translation plate along the first axis and third and fourth posts coupled to the base and configured to receive the lock screws to provide the positive lock to limit movement of the second translation plate along the second axis.

11. The simulator of claim 10 wherein the first and second axes are generally transverse and the first and second posts are spaced along the first axis and the third and fourth posts are spaced along the second axis generally transverse to the first axis.

12. The simulator of claim 10 wherein the third and fourth posts include a slot therethrough and comprising rods coupled to the first translation plate and movable along the slot of the third and fourth posts for movement of the first translation plate along the first axis and the first translation plate including upright portions having a slot therethrough and comprising rods coupled to the second translation plate and moveable along the slot of the upright portions for movement of the second translation plate along the second axis.

13. The simulator of claim 12 and comprising a spring between the third and fourth posts and the first translation plate and another spring between the upright portions and the second translation plate.

14. The simulator of claim 9 wherein the lock screws are adjustable to adjust a positive lock position along the first or second axis.

15. The simulator of claim 1 wherein the holder assembly includes first and second holders or adapters and the slide table is coupled to one of the first or second holders and comprising one or more actuators coupled to the other of the first or second holders.

16. A simulator assembly comprising:

a base;

a holder assembly configured to hold a test specimen;

a first translation plate coupled to the base through a first linear slide and rail arrangement and movable along a first axis;

a second translation plate coupled to the first translation plate through a second linear slide and rail arrangement and movable along a second axis, different from the first axis;

at least one post coupled to the base;

at least one upright portion coupled to the first translation plate;

a first spring assembly configured to input a first biasing force to the first translation plate and the first spring assembly includes a spring between the at least one post and the first translation plate to input the first biasing force; and

a second spring assembly configured to input a second biasing force to the second translation plate and the second spring assembly includes a spring between the at least one upright portion and the second translation plate to input second the biasing force.

17. The assembly of claim 16, wherein the first and second linear slide and rail arrangements include double row/side roller bearings.

18. The assembly of claim 16 including a first rod coupled to the first translation plate and a second rod coupled to the second translation plate wherein the at least one post and the at least one upright portion include a slot therethrough and the first rod is movable through the slot of the at least one post and the second rod is movable through the slot of the at least one upright portion.

19. The assembly of claim 18 and comprising a plurality of posts coupled to the base and a plurality of upright portions coupled to the first translation plate and including a plurality of first rods coupled to the first translation plate and movable through first slots of the plurality of posts coupled to the base and a plurality of second rods coupled to the second translation plate and moveable through second slots of the plurality of upright portions.

20. The assembly of claim 19 wherein each of the first and second translation plates include pairs of arms and the plurality of first and second rods are coupled between the pairs of arms on the first and second translation plates.

21. The assembly of claim 19 wherein the plurality of upright posts include openings configured to receive lock screws to provide a positive lock to limit stroke of the second translation plate along the second axis.

22. The assembly of claim 19 wherein the base includes lock screw openings configured to receive lock screws to provide a positive lock to limit stroke of the first translation plate along the first axis.

23. The assembly of claim 16 wherein the holder assembly comprises first and second holders to hold the test specimen therebetween and the first and second translation plates are coupled to the first holder and comprising at least one actuator coupled to the first holder and configured to supply a load force to the test specimen through the first and second translation plates.

24. An orthopedic simulator comprising:

a holder assembly configured to hold a test specimen;

a multi-axis slide table coupled to the holder assembly, the multi-axis slide table including;

a first translation plate mounted to a base through a first linear slide and rail assembly and movable along a first axis;

a second translation plate mounted to the first translation plate through a second linear slide and rail assembly and movable along a second axis different from the first axis; and

a soft tissue simulating arrangement coupled to the first and second translation plates to simulate forces or input from soft tissue.

25. The simulator of claim 24 wherein the soft tissue simulating arrangement comprises a plurality of springs to provide a biasing force to simulate the forces or input from the soft tissue.

26. The simulator of claim 25 wherein the plurality of springs includes at least one spring configured to supply a first biasing force relative to the first translation plate along the first axis and at least one spring configured to supply a second biasing force relative to the second translation plate along the second axis.

27. The simulator of claim 25 wherein the holder assembly comprises first and second holders to hold the test specimen therebetween and the first and second translation plates are coupled to the first holder and comprising at least one actuator coupled to the first holder and configured to supply a load force to the test specimen through the first and second translation plates.

28. The simulator of claim 27 and comprising at least one actuator coupled to the second holder and configured to supply another load force to the test specimen through the second holder.