Duty cycle loading for orthopedic simulator

Abstract

An orthopedic simulator is provided with a mechanism configured to apply motions and forces to a test specimen, such as a spinal implant, and a controller configured to control the mechanism to selectively apply the motions and forces in accordance with sinusoidal and non-sinusoidal curves.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front, perspective view of an orthopedic simulator in accordance with certain embodiments of the invention, with an external housing removed for illustrative purposes, and with forces being schematically depicted.

FIG. 2 a is a top view of the orthopedic simulator of FIG. 1; FIG. 2b is a front view; FIG. 2c is a bottom view and FIG. 2d is a side view.

FIG. 3 is a view similar to FIG. 1, illustrating the removability of a specimen containment module.

FIG. 4 depicts an exemplary embodiment of an assembled specimen containment module.

FIG. 5 is an exploded view of the specimen containment module of FIG. 4.

FIG. 6 is a side, partially cross-sectional view of the specimen containment module of FIG. 4.

FIG. 7 is a top view of a base of the specimen containment module of FIG. 4.

FIG. 8 is a schematic depiction of an embodiment of a circulation loop for circulating a temperature control fluid in a temperature control circuit.

FIG. 9 depicts two test stations, with one test station having a specimen containment module releasably attached thereto.

FIG. 10 schematically depicts an exemplary arrangement for circulating bath fluid.

FIG. 11 depicts an embodiment of a specimen containment module in an installed position.

FIG. 12 is a perspective view of the orthopedic simulator of FIG. 1, with an indication of the flexion and extension motion.

FIG. 13 is a cross-sectional view of a portion of a flexion/extension motion linkage in accordance with embodiments of the invention.

FIG. 14 is a perspective view of the orthopedic simulator of FIG. 1, with an indication of the lateral bending motion around an axis of rotation.

FIG. 15 is a rear perspective view of the orthopedic simulator of FIG. 1.

FIG. 16 is a perspective view of the orthopedic simulator of FIG. 1, with an indication of anterior/posterior and lateral translation motions.

FIG. 17 depicts a portion of an x-y slide assembly in accordance with embodiments of the present invention.

FIG. 18 is a perspective view of the x-y slide assembly in accordance with embodiments of the present invention.

FIG. 19 is an exploded view of the x-y slide assembly of FIG. 18.

FIG. 20 is a perspective view of the orthopedic simulator of FIG. 1, with an indication of loading in a vertical direction.

FIG. 21 is a perspective view of an embodiment of an actuator in isolation.

FIG. 22 is a top view of the actuator of FIG. 21.

FIG. 23 is a side view of the actuator of FIG. 21.

FIG. 24 is a cross-sectional view of the actuator of FIG. 21.

FIG. 25 is a perspective view of the orthopedic simulator of FIG. 1, with an indication of the axial rotation linkage and a moment provided at a test specimen.

FIG. 26 is a rear perspective view of the orthopedic simulator of FIG. 1, illustrating an embodiment of a central manifold in accordance with embodiments of the present invention.

FIGS. 27-29 schematically depict different approaches to linkages.

FIG. 30 schematically depicts a nesting order of forces in accordance with embodiments of the present invention.

FIG. 31 shows the required forces for application to a test specimen intended for a lumbar region according to an exemplary set of curves.

FIG. 32 shows the same information as FIG. 31, but for cervical data.

FIG. 33 shows curves for non-sinusoidal input data in accordance with exemplary embodiments of the invention.

FIG. 34 depicts the orthopedic simulator within a housing.

Claims

1. An orthopedic simulator comprising: a mechanism configured to apply motions and forces to a test specimen; and;a controller configured to control the mechanism to apply the motions and forces with duty cycle loading.

2. The simulator of claim 1, wherein the duty cycle loading includes at least one of a periodic overload or overmotion state.

3. The simulator of claim 2, wherein the mechanism is controlled by the controller to apply the motions and forces according to sinusoidal curves, with the insertion of the periodic overload states at prescribed intervals or overmotion.

4. The simulator of claim 3, wherein the mechanism applies the motions and forces with six degrees of freedom, with motions and forces being applied to at least some of the six degrees of freedom.

5. The simulator of claim 4, wherein the mechanism comprises a plurality of motion devices that apply the motions and forces, wherein the controller is configured to individually and independently control at least some of the motion devices.

6. The simulator of claim 5, wherein the test specimen is a spinal implant, and the motion devices include flexion/extension, lateral bending and rotation motion devices.

7. An orthopedic simulator comprising: a mechanism configured to apply motions and forces to a test specimen; anda controller configured to control the mechanism to selectively apply the motions and forces in accordance with sinusoidal and non-sinusoidal curves.

8. The simulator of claim 7, wherein the controller is configured to variably control phase, amplitude and frequency content of the sinusoidal and non-sinusoidal curves.

9. The simulator of claim 8, wherein the sinusoidal and non-sinusoidal curves represent replicated activities.

10. The simulator of claim 9, wherein the test specimen is a spinal implant, and the motions and forces include flexion/extension, lateral bending and rotation.

11. The simulator of claim 10, wherein the mechanism applies the motions and forces with six degrees of freedom, with motions and forces being applied to at least some of the six degrees of freedom.

12. The simulator of claim 11, wherein the mechanism comprises a plurality of motion devices that apply the motions and forces, wherein the controller is configured to individually and independently control at least some of the motion devices.

13. The simulator of claim 12, wherein the controller is configured to control the motion devices to apply the motions and forces with duty cycle loading.

14. The simulator of claim 13, wherein the sinusoidal and non-sinusoidal curves represent forces and motions applied to a test specimen in accordance with a model of actual human activity.

15. A method of testing an orthopedic device in an orthopedic simulator wear test machine, comprising the steps: controlling a mechanism to apply motions and forces to a test specimen;wherein the motions and forces are controlled to selectively apply the motions and forces in accordance with sinusoidal and non-sinusoidal curves.

16. The method of claim 15, wherein the motions and forces are controlled to control phase, amplitude and frequency content of the non-sinusoidal curves.

17. The method of claim 16, wherein the test specimen is a spinal implant, and the motions and forces include flexion/extension, lateral bending and rotation.

18. The method of claim 17, wherein the mechanism comprises a plurality of motion devices that apply the motions and forces, and further comprising individually and independently controlling each of the motion devices so as to apply the motions and forces in accordance with the sinusoidal and non-sinusoidal curves.

19. The method of claim 18, further comprising applying the motions and forces with duty cycle loading.

20. The method of claim 15, wherein the sinusoidal and non-sinusoidal curves represent a model of actual human activity.