COMBINED ACTIVE AND PASSIVE LEG PROSTHESIS SYSTEM AND A METHOD FOR PERFORMING A MOVEMENT WITH SUCH A SYSTEM

• US 20130204395A1
• Filed: 03/18/2013
• Published: 08/08/2013
• Est. Priority Date: 04/19/2005
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Ossur hf
• Inventors: Gramnaes, Lisa
• Granted Patent: US 9,066,819 B2
• Time in Patent Office: Days
• US Class Current: 623/26
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/66 Feet; Ankle joints
• CPC Class Codes: A61F 2/6607 Ankle joints
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2/72 Bioelectric control, e.g. myoelectric
• CPC Class Codes: A61F 2/74 fluid , i.e. hydraulic or pneumatic
• CPC Class Codes: A61F 2/741 using powered actuators, e.g. stepper motors or solenoids
• CPC Class Codes: A61F 2/748 Valve systems
• CPC Class Codes: A61F 2002/5038 Hinged joint, e.g. with transverse axle restricting the movement
• CPC Class Codes: A61F 2002/607 Lower legs
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/6818 for braking
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/705 Electromagnetic data transfer
• CPC Class Codes: A61F 2002/7625 for measuring angular position
• CPC Class Codes: A61F 2002/763 for measuring spatial position, e.g. global positioning system [GPS]
• CPC Class Codes: A61F 2002/764 for measuring acceleration
• CPC Class Codes: A61F 2002/7655 for measuring fluid pressure

Abstract

A lower limb prosthesis system and a method of controlling the prosthesis system to replace a missing lower extremity of an individual and perform a gait cycle are disclosed. The prosthesis system has a controller, one or more sensors, a prosthetic foot, and a movable ankle joint member coupled to the prosthetic foot. The movable ankle joint member comprises a hydraulic damping system that provides the ankle joint member damping resistance. The controller varies the damping resistance by providing volumetric flow control to the hydraulic damping system based on sensor data. In one embodiment, the hydraulic damping system comprises a hydraulic piston cylinder assembly, hydraulic fluid, and a valve to regulate the fluid. In one embodiment, the controller alters the damping resistance by modulating the valve to vary the hydraulic fluid flow within the hydraulic piston cylinder assembly of the movable ankle joint member based on sensor data.

Claims

1. A lower limb prosthesis for replacing a missing lower extremity of an individual, said lower limb prosthesis comprising:

a prosthetic foot member;

a movable ankle joint member coupled to the prosthetic foot member, the ankle joint member comprising

a hydraulic assembly comprising

a hydraulic cylinder,

a piston configured to move axially within the hydraulic cylinder between a first hydraulic chamber on one side of the piston and a second hydraulic chamber on an opposite side of the piston as the prosthetic foot member moves relative to the ankle joint member, the hydraulic chambers are defined in the hydraulic cylinder at least in part by the piston, and

a valve actuatable to fluidly communicate the first and second hydraulic chambers, the valve configured to regulate hydraulic fluid flow between the hydraulic chambers so as to vary damping resistance of the ankle joint member;

one or more sensors configured to sense one or more parameters associated with the motion of the lower limb prosthesis during ambulation; and

a controller configured to receive input data from the one or more sensors corresponding to the one or more sensed parameters, the controller configured to control the operation of the valve to selectively actuate the valve to vary the damping resistance of the ankle joint member based at least in part on the one or more sensed parameters.

2. The lower limb prosthesis of claim 1, wherein the controller is further configured to control a motor to move the valve to an open position so that an orientation of the prosthetic foot member relative to the ankle joint member varies during ambulation.

3. The lower limb prosthesis of claim 2, wherein opening the valve to a fully open position allows the ankle joint member to operate in an unbraked or freely swinging manner.

4. The lower limb prosthesis of claim 1, wherein the one or more sensed parameters are selected from the group consisting of acceleration, speed, angular velocity, position, ground inclination angle, and pressure.

5. The lower limb prosthesis of claim 1, wherein the movement of the piston results in an adjustment of an angle between the ankle joint member and the prosthetic foot member, thereby altering an orientation of the ankle joint member relative to the prosthetic foot member.

6. A lower limb prosthesis for replacing a missing lower extremity of an individual, said lower limb prosthesis comprising:

a prosthetic foot member;

an ankle joint member pivotably coupled to the prosthetic foot member, the ankle joint member comprising a hydraulic damping system; and

a controller configured to receive input data from one or more sensors on the lower limb prosthesis, to determine a damping resistance adjustment needed for the lower limb prosthesis based at least in part on the received input data, and to communicate an output signal to modify a damping resistance of the ankle joint member,

wherein the hydraulic damping system is configured, based at least in part on the output signal from the controller, to regulate flow of a hydraulic fluid to adjust the damping resistance provided by the hydraulic damping system to the pivotable ankle joint member, and

wherein the hydraulic damping system comprises a hydraulic cylinder and a piston configured to move axially within the hydraulic cylinder between a first hydraulic chamber on one side of the piston and a second hydraulic chamber on an opposite side of the piston, the first and second hydraulic chambers are defined in the hydraulic cylinder at least in part by the piston.

7. The lower limb prosthesis of claim 6, wherein the input data is related to a parameter selected from the group consisting of acceleration, speed, angular velocity, position, ground inclination angle, and pressure.

8. The lower limb prosthesis of claim 6, wherein the hydraulic damping system comprises a valve actuatable to fluidly communicate the first and second hydraulic chambers, the valve is configured to regulate hydraulic fluid flow between the hydraulic chambers so as to vary the damping resistance of the ankle joint member.

9. The lower limb prosthesis of claim 8, wherein the movement of the piston results in an adjustment of an angle between the ankle joint member and the prosthetic foot member, thereby altering an orientation of the ankle joint member relative to the prosthetic foot member.

10. The lower limb prosthesis of claim 8, wherein the controller is further configured to control a motor to move the valve to an open position so that an orientation of the prosthetic foot member relative to the ankle joint member varies during ambulation.

11. The lower limb prosthesis of claim 10, wherein opening the valve to the open position allows the ankle joint member to operate in an unbraked or freely swinging manner.

12. The lower limb prosthesis of claim 6, wherein the piston is configured to move axially within the hydraulic cylinder when the piston is not locked by the controller.

13. The lower limb prosthesis of claim 6, further comprising an active drive unit arranged to actively drive the ankle joint member during at least a portion of a gait cycle by providing power to the ankle joint member, wherein the power causes the ankle joint member to perform a movement.

14. The lower limb prosthesis of claim 13, wherein the active drive unit comprises a hydraulic pump.

15. The lower limb prosthesis of claim 6, wherein the input data comprises position data.

16. The lower limb prosthesis of claim 15, wherein the one or more sensors comprise a position sensor.

17. A method of controlling a lower leg prosthesis for replacing a missing lower extremity of an individual, said method comprising:

sensing parameters related to motion of the lower leg prosthesis with one or more sensors and generating input data based on the parameters;

transmitting a signal based on the input data from the one or more sensors to a controller;

determining, based at least in part on the input data, a damping resistance adjustment for the lower leg prosthesis; and

adjusting a damping resistance of a hydraulic ankle module of the lower leg prosthesis via a motor actuatable valve, the hydraulic ankle module comprising an ankle joint and a piston axially slidable in a hydraulic cylinder.

18. The method of claim 17, wherein the valve is configured to communicate a first hydraulic chamber and a second hydraulic chamber in the hydraulic cylinder, the valve is configured to regulate hydraulic fluid flow between the first and second hydraulic chambers so as to vary the damping resistance of the hydraulic ankle module.

19. The method of claim 18, wherein adjusting the damping resistance of the hydraulic ankle module includes opening the valve so that the hydraulic ankle module pivots relative to a prosthetic foot member coupled to the hydraulic ankle module during ambulation.

20. The method of claim 19, wherein axially sliding the piston in the hydraulic cylinder results in adjusting an angle between the hydraulic ankle module and the prosthetic foot member coupled to the hydraulic ankle module, thereby altering an orientation of the hydraulic ankle module.