Abstract: A prosthetic device includes a frame defining an output axis, a cantilever beam spring attached to the frame, a moment arm attached to the spring, and a rigid output arm coupled to the frame and rotatable about the output axis. A connector assembly is configured to apply a moment to the cantilever beam spring via the moment arm while applying a torque about the output axis via the output arm. An ankle-foot device includes foot and ankle members connected for two-degree of freedom movement relative to one another, allowing for rotation about an ankle axis and rotation about a subtalar axis. Two linear actuators, each coupled to corresponding series elastic element, link the foot and ankle members. Driving the actuators in the same direction causes rotation about the ankle axis and driving the actuators in opposing directions causes rotation about the subtalar axis. A processor receives sensory information from a sensor and drives the actuators to control an equilibrium position of the series elastic elements.

Abstract: An artificial foot and ankle joint consists of a curved leaf spring foot member having a heel extremity and a toe extremity, and a flexible elastic ankle member that connects the foot member for rotation at the ankle joint. An actuator motor applies torque to the ankle joint to orient the foot when it is not in contact with the support surface and to store energy in a catapult spring that is released along with the energy stored in the leaf spring to propel the wearer forward. A ribbon clutch prevents the foot member from rotating in one direction beyond a predetermined limit position. A controllable damper is employed to lock the ankle joint or to absorb mechanical energy as needed. The controller and sensing mechanisms control both the actuator motor and the controllable damper at different times during the walking cycle for level walking, stair ascent, and stair descent.

Abstract: Proprioceptive feedback is provided in a residual limb of a person that includes forming a linkage between a pair of agonist and antagonist muscles, forming a sliding surface over which the agonist and antagonist muscles slide. The sliding surface can include a synovial sleeve, a bridge formed between the distal ends of bones, or a fixture that is osseointegrated into the bone. The invention also includes a system for transdermal electrical communication in a person that includes a percutaneous access device, a sensory device that communicates signals between a muscle and the percutaneous device, and a stimulation device in communication with the percutaneous access device. In another embodiment, a closed-loop functional stimulation system restores lost functionality to a person that suffers from impairment of a neurological control system or at least partial loss of a limb.

Abstract: The system includes an instrument for determining the anatomical, biomechanical, and physiological properties of a body segment that includes one or more force sensitive probes is provided. A human operator actuates one or more force sensitive probes, wherein the force sensitive probes are positioned at the surface of the body segment. The operator pushes on the force sensitive probes with varying force applied on the body segment to measure tissue deflection forces. The instrument may include one or more of gyroscopes, accelerometers, and magnetometers capable of measuring changes in tissue deflection caused by the force sensitive probes relative to a grounded reference frame in 3-D space, wherein the tissue deflection force data and the change in tissue deflection data are used to compute segment tissue viscoelastic properties. The instrument may also be untethered or wireless.

Abstract: Proprioceptive feedback is provided in a residual limb of a person that includes forming a linkage between a pair of agonist and antagonist muscles, forming a sliding surface over which the agonist and antagonist muscles slide. The sliding surface can include a synovial sleeve, a bridge formed between the distal ends of bones, or a fixture that is osseointegrated into the bone. The invention also includes a system for transdermal electrical communication in a person that includes a percutaneous access device, a sensory device that communicates signals between a muscle and the percutaneous device, and a stimulation device in communication with the percutaneous access device. In another embodiment, a closed-loop functional stimulation system restores lost functionality to a person that suffers from impairment of a neurological control system or at least partial loss of a limb.

Abstract: Devices and methods for obtaining external shapes and internal tissue geometries, as well as tissue behaviors, of a biological body segment are provided. A device for three-dimensional imaging of a biological body segment includes a structure configured to receive the biological body segment, the structure including a first array of imaging devices disposed about a perimeter of the device to capture side images of the biological body segment and a second array of imaging devices disposed at an end of the device to capture images of a distal portion of the biological body segment. The second array has a generally axial viewing angle relative to the perimeter. A controller is configured to generate a three-dimensional reconstruction of the biological body segment based on cross-correlation of captured images from the first and second arrays.

Abstract: At least partial function of a human limb is restored by surgically removing at least a portion of an injured or diseased human limb from a surgical site of an individual and transplanting a selected muscle into the remaining biological body of the individual, followed by contacting the transplanted selected muscle, or an associated nerve, with an electrode, to thereby control a device, such as a prosthetic limb, linked to the electrode. Simulating proprioceptive sensory feedback from a device includes mechanically linking at least one pair of agonist and antagonist muscles, wherein a nerve innervates each muscle, and supporting each pair with a support, whereby contraction of the agonist muscle of each pair will cause extension of the paired antagonist muscle. An electrode is implanted in a muscle of each pair and electrically connected to a motor controller of the device, thereby simulating proprioceptive sensory feedback from the device.

Abstract: A mechanical interface connecting a biological body segment, such as a limb, portion of a limb or other body segment, to a wearable device such as a prosthetic, orthotic or exoskeletal device, is fabricated by quantitatively mapping a characterized representation of the body segment to form a digital representation of the mechanical interface shape and mechanical interface impedance. The mechanical interface includes a continuous socket defining a contoured inside surface and a contoured outside surface, and includes a material having an intrinsic impedance that varies through the material, so that the intrinsic impedance varies along the contoured inside surface.

Abstract: At least partial function of a human limb is restored by surgically removing at least a portion of an injured or diseased human limb from a surgical site of an individual and transplanting a selected muscle into the remaining biological body of the individual, followed by contacting the transplanted selected muscle, or an associated nerve, with an electrode, to thereby control a device, such as a prosthetic limb, linked to the electrode. Simulating proprioceptive sensory feedback from a device includes mechanically linking at least one pair of agonist and antagonist muscles, wherein a nerve innervates each muscle, and supporting each pair with a support, whereby contraction of the agonist muscle of each pair will cause extension of the paired antagonist muscle. An electrode is implanted in a muscle of each pair and electrically connected to a motor controller of the device, thereby simulating proprioceptive sensory feedback from the device.

Abstract: A method for controlling a powered device to augment a joint function of a human during a gait cycle using a powered actuator that supplies an augmentation torque, an impedance, or both to a joint is disclosed. In some embodiments, the method modulates the augmentation torque, the impedance, and a joint equilibrium according to a phase of the gait cycle to provide at least a biomimetic response. Accordingly, the actuator is capable of normalizing or augmenting human biomechanical function, responsive to a wearer's activity, regardless of speed and terrain.

Abstract: A mechanical interface connecting a biological body segment, such as a limb, portion of a limb or other body segment, to a wearable device such as a prosthetic, orthotic or exoskeletal device, is fabricated by quantitatively mapping a characterized representation of the body segment to form a digital representation of the mechanical interface shape and mechanical interface impedance. The mechanical interface includes a continuous socket defining a contoured inside surface and a contoured outside surface, and includes a material having an intrinsic impedance that varies through the material, so that the intrinsic impedance varies along the contoured inside surface.

Abstract: A physiological feature of a subject is monitored by implanting a plurality of targets, such as magnets, and detecting at least one change in a physical property of the targets, followed by modifying a physiological feature of the subject in response to a change of state detected by the change in physical property detected in the targets. Cutaneous sensory feedback and proprioceptive feedback in a subject, as well as selective stimulation of axons or nerve fascicles of a neuron of a subject are provided.

Abstract: A prosthetic device includes a frame defining an output axis, a cantilever beam spring attached to the frame, a moment arm attached to the spring, and a rigid output arm coupled to the frame and rotatable about the output axis. A connector assembly is configured to apply a moment to the cantilever beam spring via the moment arm while applying a torque about the output axis via the output arm. An ankle-foot device includes foot and ankle members connected for two-degree of freedom movement relative to one another, allowing for rotation about an ankle axis and rotation about a subtalar axis. Two linear actuators, each coupled to corresponding series elastic element, link the foot and ankle members. Driving the actuators in the same direction causes rotation about the ankle axis and driving the actuators in opposing directions causes rotation about the subtalar axis. A processor receives sensory information from a sensor and drives the actuators to control an equilibrium position of the series elastic elements.

Abstract: An electromyography (EMG) sensor for a wearable device, such as a prosthetic device attachable to a residual limb, includes a flexible substrate comprising an elongated portion and an electrode portion. At least two electrodes are disposed at a surface of the electrode portion of the flexible substrate, and leads from the at least two electrodes extend through the elongated portion of the flexible substrate.

Abstract: A powered device augments a joint function of a human during a gait cycle using a powered actuator that supplies an augmentation torque, an impedance, or both to a joint. A controller estimates terrain slope and modulates the augmentation torque and the impedance according to a phase of the gait cycle and the estimated terrain slope to provide at least a biomimetic response. The controller may also modulate a joint equilibrium. Accordingly, the device is capable of normalizing or augmenting human biomechanical function, responsive to a wearer's activity, regardless of speed and terrain, and can be used, for example, as a knee orthosis, prosthesis, or exoskeleton.

Abstract: It is to be understood that the methods and apparatus which have been described above are merely illustrative applications of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.

Abstract: Hybrid terrain-adaptive lower-extremity apparatus and methods that perform in a variety of different situations by detecting the terrain that is being traversed, and adapting to the detected terrain. In some embodiments, the ability to control the apparatus for each of these situations builds upon five basic capabilities: (1) determining the activity being performed; (2) dynamically controlling the characteristics of the apparatus based on the activity that is being performed; (3) dynamically driving the apparatus based on the activity that is being performed; (4) determining terrain texture irregularities (e.g., how sticky is the terrain, how slippery is the terrain, is the terrain coarse or smooth, does the terrain have any obstructions, such as rocks) and (5) a mechanical design of the apparatus that can respond to the dynamic control and dynamic drive.

Abstract: A link extends between a distal member and a proximal member of a wearable device, such as an exoskeleton, orthosis or prosthesis for a human lower limb. One or other of the distal member and the proximal member includes a crossing member. The link extends from the crossing member of the distal member or the proximal member, to the other of the distal member or the proximal member. Actuation of the link translates to a force at the distal or proximal member that is normal to a major longitudinal axis extending through the distal and proximal members. In one embodiment, a sliding link of a device configured for use with a human joint tracks two degrees of freedom of the joint.

Abstract: A nerve in a mammal is optogenetically transduced, wherein the nerve is susceptible to stimulus by selective application of transdermal light, and a light source is applied to dermis of the mammal at or proximate to the optogenetically transduced nerve, to thereby stimulate the nerve. A wearable device for optogenetic motor control and sensation restoration of a mammal includes a wearable support, a power source at the wearable support, a controller at the wearable support and in electrical communication with a power source, and a transdermal light source coupled to the controller.

Abstract: Artificial limbs and joints that behave like biological limbs and joints employ a synthetic actuator which consumes negligible power when exerting zero force, consumes negligible power when outputting force at constant length (isometric) and while performing dissipative, nonconservative work, is capable of independently engaging flexion and extension tendon-like, series springs, is capable of independently varying joint position and stiffness, and exploits series elasticity for mechanical power amplification.