An approximation method and system are provided for more quickly controlling a prosthetic or other device by reducing computational processing time in a muscle model that can be used to control the prosthetic. For a given muscle, the approximation method can quickly compute polynomial structures for a muscle length and for each associated moment arms, which may be used to generate a torque for a joint position of a physics model. The physics model, in turn, produces a next joint position and velocity data for driving a prosthetic. The approximation method expands the polynomial structures as long as expansion is possible and sufficiently beneficial. The computations can be performed quickly by expanding the polynomial structures in a way that constrains the muscle length polynomial to the moment arm polynomial structures, and vice versa.

Actuators and methods of use are provided. An actuator may include an inner member made from an elastic material and defining a compartment for receiving an actuating fluid, the inner member being moveable in a longitudinal direction from a relaxed state to an expanded state by introducing an actuating fluid into the inner member; and an outer member made from an inelastic material and being disposed around the elastic inner member to control expansion of the elastic inner member in a radial direction, the outer member being moveable from a folded relaxed configuration to an unfolded extended configuration as the inner member moves from the relaxed state to the expanded state, wherein the movement of the actuator between the relaxed state and the expanded state causes a movement of a structure to which the actuator is attached.

The present invention relates to a soft actuator moving linearly against external stimuli whose expansion and contraction can be actively controlled, suggesting that the actuator of the invention overcomes the problems of the conventional soft actuators, The soft actuator of the present invention can be repetitively driven quickly and accurately by controlling heating and cooling by using thermoelectric effect and, the soft actuator of the present invention can realize bending, tensioning, compression, and rotational driving of a tubular device containing a driver.

A system and method for controlling a device, such as a prosthetic limb are provided. A biomimetic controller of the system comprises a signal processor and a musculoskeletal model. The signal processor processes M biological signals received from a residual limb to transform the M biological signals into N activation signals, where M and N are integers and M is less than N. The musculoskeletal model transforms the N activation signals into intended motion signals. A prosthesis controller transforms the intended motion signals into three or more control signals that are outputted from an output port of the prosthesis controller. A controlled device receives the control signals and performs one or more tasks in accordance with the control signals.

Actuators and methods of use are provided. An actuator may include an inner member made from an elastic material and defining a compartment for receiving an actuating fluid, the inner member being moveable in a longitudinal direction from a relaxed state to an expanded state by introducing an actuating fluid into the inner member; and an outer member made from an inelastic material and being disposed around the elastic inner member to control expansion of the elastic inner member in a radial direction, the outer member being moveable from a folded relaxed configuration to an unfolded extended configuration as the inner member moves from the relaxed state to the expanded state, wherein the movement of the actuator between the relaxed state and the expanded state causes a movement of a structure to which the actuator is attached.

Novel robust electroactive polymers (EAPs) and EAP-based systems are described, which contract and expand at low voltages to provide for a shape-morphing system, which also sense mechanical pressure, from gentle touch to high impact, and which attenuate force. These EAPs and EAP-based systems can be used in a prosthetic liner, and potentially as the entire prosthetic liner, in a prosthetic hard socket, in shoe wear, sports gear, protective gear, and military gear, and in compression equipment, to contract and expand in strategic areas as needed to maintain a perfect fit, to sense pressure and provide feedback to automatically maintain perfect fit, and to attenuate force for an extremely comfortable fit.

A hinge-type actuator device in accordance with the present disclosure may include a first and second paddle, a first and second artificial muscle actuator segment, and a plurality of contacts, where the first and second artificial muscle actuator segments are actuated via the contacts, actuation of the first artificial muscle actuator segment causes the first and second paddle to open the hinge-type actuator, and actuation of the second artificial muscle actuator segment causes the first and second paddle to close the hinge-type actuator.

A soft buckling linear actuator is described, including: a plurality of substantially parallel bucklable, elastic structural components each having its longest dimension along a first axis; and a plurality of secondary structural components each disposed between and bridging two adjacent bucklable, elastic structural components; wherein every two adjacent bucklable, elastic structural components and the secondary structural components in-between define a layer comprising a plurality of cells each capable of being connected with a fluid inflation or deflation source; the secondary structural components from two adjacent layers are not aligned along a second axis perpendicular to the first axis; and the secondary structural components are configured not to buckle, the bucklable, elastic structural components are configured to buckle along the second axis to generate a linear force, upon the inflation or deflation of the cells. Methods of actuation using the same are also described.

An upper extremity prosthesis may include a prosthetic hand including a prosthetic thumb having a base and a tip, and a prosthetic index finger having a base and a tip. Actuators may be coupled to the upper extremity prosthesis. Prosthetic flexion tendons may have first ends operably coupled to the actuators and second ends coupled to the tips of the thumb and the index finger. Biasing systems may be operably coupled to the prosthetic thumb and the index finger. Upon actuation of the actuators in a first direction, the prosthetic flexion tendons cause the thumb and index finger to flex. Upon actuation of the linear actuators in a second direction opposite the first direction, the biasing systems cause the thumb and index finger to extend.

A model-based neuromechanical controller for a robotic limb having at least one joint includes a finite state machine configured to receive feedback data relating to the state of the robotic limb and to determine the state of the robotic limb, a muscle model processor configured to receive state information from the finite state machine and, using muscle geometry and reflex architecture information and a neuromuscular model, to determine at least one desired joint torque or stiffness command to be sent to the robotic limb, and a joint command processor configured to command the biomimetic torques and stiffnesses determined by the muscle model processor at the robotic limb joint. The feedback data is preferably provided by at least one sensor mounted at each joint of the robotic limb. In a preferred embodiment, the robotic limb is a leg and the finite state machine is synchronized to the leg gait cycle.