Combined active and passive leg prosthesis system and a method for performing a movement with such a system

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,
• 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, the hydraulic damping system further comprising a fluid flow path disposed outside of the hydraulic cylinder, wherein hydraulic fluid is configured to flow between the first and second hydraulic chambers via the fluid flow path, and
• 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.

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, the actuatable valve disposed outside the hydraulic cylinder,
• 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,
• 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, and
• 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.