Control system and method for a prosthetic knee

• US 8,617,254 B2
• Filed: 01/22/2010
• Issued: 12/31/2013
• Est. Priority Date: 03/10/2004
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Ossur hf
• Inventors: Bisbee, Charles R III, Elliott, Scott B, Oddson, Magnus
• Primary Examiner(s): Sweet, Thomas J
• Assistant Examiner(s): PRESTON, REBECCA STRASZHEIM
• Application Number:
  US12/692,438
• Publication Number:
  US 20100185124A1
• Time in Patent Office: 1,439 Days
• Field of Search: None
• US Class Current: 623/24
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2002/5003 having damping means, e.g. shock absorbers for implantable joints A61F2002/30563
• CPC Class Codes: A61F 2002/5004 operated by electro- or magnetorheological fluids
• CPC Class Codes: A61F 2002/5033 for adjusting damping damping means A61F2002/5003
• CPC Class Codes: A61F 2002/6863 magnetic magnetic prosthetic parts A61F2002/30079
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/705 Electromagnetic data transfer for implantable prostheses A61F2250/0002
• CPC Class Codes: A61F 2002/7625 for measuring angular position
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/764 for measuring acceleration
• CPC Class Codes: A61F 2250/0034 differing in viscosity

Abstract

A prosthetic or orthotic system including a magnetorheological (MR) damper. The MR damper may be configured to operate in shear mode. In one embodiment, the MR damper includes a rotary MR damper. A controller is configured to operate the damper. A mobile computing device may be adapted to intermittently communicate configuration parameters to the controller. A method of configuring a prosthetic or orthotic system is also disclosed.

Claims

1. A method of controlling a prosthetic having a movement damper, comprising:

measuring at least one characteristic of prosthetic movement;

calculating a damping value based at least partly on the at least one characteristic;

applying a filter, wherein the filter receives a calculated current, to filter the damping value based at least partly on input of values of previous damping values to the filter; and

applying the damping value to control resistance of a damper.

2. The method of claim 1, wherein applying the damping value comprises applying the damping value to a rotary magnetorheological damper operating in shear mode.

3. The method of claim 1, wherein measuring the at least one characteristic of prosthetic movement comprises measuring a knee angle.

4. The method of claim 1, wherein measuring the at least one characteristic of prosthetic movement comprises measuring load using a load sensor.

5. The method of claim 4, wherein the load sensor comprises at least one strain gauge.

6. The method of claim 1, wherein the damper is configured to vary resistance to rotation in response to the current.

7. The method of claim 1, wherein filtering comprises filtering increases to said damping value differently than decreases to said damping value.

8. The method of claim 1, further comprising identifying a control state based at least partly on the at least one characteristic.

9. The method of claim 8, further comprising adjusting parameters for identifying the control state.

10. The method of claim 9, wherein adjusting parameters for identifying the control state is in response to receiving a signal comprising an instruction to adaptively adjust the parameters during operation of the damper.

11. The method of claim 9, wherein the parameters comprise target values for the at least one characteristic of prosthetic movement.

12. The method of claim 1, wherein the filter is a fixed point infinite impulse response filter.