Patent Description:
Many health conditions result in significant impairment to mobility, which may be short of complete paralysis. The large population of persons afflicted with such conditions include, for example, those affected by stroke, multiple sclerosis, ALS, Parkinson's disease, incomplete spinal cord injury, cerebral palsy, and many other conditions resulting from birth defects, disease, injury, or aging. To aid mobility, movement assist devices, such as leg orthotic devices, have been employed.

Traditionally, the field of orthoses has specialized in highly custom, form-fitting braces that are made to fit the unique anatomy and needs of each individual patient. Many physiological abnormalities and gait impairments demand the closely-coupled support of a custom-fabricated brace. The simplest form of such a device is a passive non-powered orthotic device with long-leg braces that extend over the knees and incorporate a pair of ankle-foot orthoses to provide support at the ankles, which are coupled with the leg braces to lock the knee joints in full extension (referred to in the art as "knee-ankle-foot-orthoses" or "KAFOs"). In another configuration, the leg brace further may be connected to a hip component that provides added support at the torso (referred to in the art as "hip-knee-ankle-foot-orthoses" or "HKAFOs"). The hips are typically stabilized by the tension in the ligaments and musculature on the anterior aspect of the pelvis. Since almost all energy for movement is provided by the upper body, ambulation with these passive orthoses require considerable upper body strength and a high level of physical exertion, and provide very slow walking speeds.

To decrease the high level of exertion associated with passive orthoses, the use of powered exoskeleton devices has been under development, which incorporate actuators and drive motors associated with a power supply to assist with locomotion. These powered exoskeleton devices have been shown to increase gait speed and decrease compensatory motions, relative to walking without powered assistance. The use of powered exoskeleton devices presents an opportunity for electronic control of the mobility assistance devices, for enhanced user mobility. However, conventional powered exoskeleton devices do not permit the desired level of customization to fit the unique anatomy and needs of each individual patient. The rigid mechanical and electrical components associated with powered actuation (e.g. electric motors, gears, structural housings, and circuit boards) have precluded high levels of customization to user body type, making integration with highly contoured bracing substantially difficult.

Human walking is characterized by relatively slow hip and knee joint rotational motion and relatively high joint torque. To aid -- partially or fully -- human walking, a variety of hydraulic, pneumatic, and electromechanical orthoses have been developed by universities and companies over the past few decades. Competing interests include maximizing torque output and controllability while minimizing weight, size, noise, and cost. Recent advancements in brushless motor technology and lithium batteries have made electromechanical actuation systems the dominant option for optimizing these tradeoffs. However, electric motors generally experience peak efficiency at relatively high rates of rotation and low torque output. This then requires a transmission system designed to reduce the speed and amplify the torque to bring the performance into a useful range for biomechanical assistance during walking. In the process of adding a transmission to provide outputs conducive to walking, high gearing ratios have often been used, having an approximate transmission ratio of between <NUM>:<NUM> and <NUM>:<NUM>. This high ratio prevents the joints from moving freely when not under power, eliminating back-drivability. This back-drivability is important for individuals who may have some function and be able to participate in the walking motion cooperatively with the mobility assistance device, as user effort to aid walking in combination with the powered assistance can have health benefits for the user and results in a smoother and more efficient gait and recovery.

As referenced above, powered exoskeleton systems have been developed, which provide mobility assistance for persons with substantial to complete paralysis. Such systems incorporate two powered leg components connected with a hip component to provide bilateral mobility assistance at the hip and knee joints. For such systems, Applicant has developed custom actuators with a low transmission ratio of approximately <NUM>:<NUM>, a low profile, and relatively low noise output, while still offering appropriate joint speeds and torques of approximately <NUM> (continuous) in a package weighing approximately <NUM> oz. An example of such a device is described in Applicant's International Patent Appl. The exoskeleton actuators of the nature described in such application are designed and sized for adults with essentially complete paralysis of the lower limbs. Thus, the size, weight, and torque generally may be too high for individuals who experience only partial mobility impairment, as would be useful for conventional orthotic devices configured as KAFOs and HKAFOs.

<CIT> describes a robotic system for simulating a wearable device actuation delivery mechanism and the source removed from the actuation delivery mechanism that is linked to the actuation delivery mechanism by at least one cable. <CIT> describes a double-lasso driving flexible joint used for an exoskeleton robot. <CIT> describes a hip joint assisting rehabilitation device based on sleeve rope transmission. <CIT> describes a wearable lower limb exoskeleton driven by lasso artificial muscle. <CIT> describes a rope-drive-based assisted knee joint rehabilitation apparatus.

The present invention provides an actuation system as defined in appended claim <NUM>.

The actuator system is for joints for powered orthotic devices, and KAFO and HKAFO devices in particular, that can be readily integrated with standard orthotic bracing that can be customized to user body type. Such actuation system provides a smaller and lighter solution for powering wearable orthotic systems, which should also require less torque that is more suitable for orthotic devices as compared to more comprehensive exoskeleton systems in which joint actuation systems previously have been employed. The present invention addresses the deficiencies of conventional configurations by minimizing the size of the driven joint, and by allowing the drive unit to be located remotely relative to the driven joint, transmitting power via flexible cabling such as for example Bowden cables. With such configuration, varus and valgus angling at the human knee joint and/or hip abduction or adduction in the frontal plane is optimized for walking.

In exemplary embodiments, an actuator system for a powered orthotic device is configurated as a high torque, low profile actuator with a flat electric motor and a two-stage speed reduction drive transmission. The two-stage transmission may include belt/chain/cable stages, with the output portion of the final stage and driven joint member being attached remotely from the input portion of the final stage, and from the first stage of the transmission, through Bowden cable sheaths. More particularly, in exemplary embodiments the first stage includes a small diameter belt pulley or sprocket attached to a shaft of a flat profile brushless motor, which transmits power to a larger belt pulley or sprocket to form the first stage of speed reduction. The larger belt pulley or sprocket is attached to the same shaft as another small diameter sprocket. This small diameter sprocket transmits power to another sprocket of larger diameter through a roller chain to form the second stage of speed reduction. Cables are attached to the second stage sprocket, for example by means of connection to a second roller chain using suitable fittings (for example crimp fittings), and free ends of the cables are opposingly are routed through Bowden cable sheaths. The cables then are attached to a driven joint member that acts as a cable pulley for driving a joint in an orthotic device.

By using flexible cabling that is routed through cable sheaths to span the second stage, the large cable pulley that provides the output, and along with it the driven joint member, are located remotely from drive motor and the first stage. The cable/sheath configuration permits a degree of flexibility in positioning the driven joint member relative to the actuator assembly containing the drive unit. Accordingly, the actuator system may be integrated into a wide range of standard orthotic devices that may be customized to user body type, i.e., the actuator system is suitable for use with any standard type bracing as fitted to a given user body type without the need for additional customization of the actuator system itself.

An aspect of the invention is an enhanced actuator system for an orthotic device that may be incorporated into customized orthotic devices by remotely positioning the driven joint member from the actuator assembly via flexible cabling. In exemplary embodiments, an actuator system for a powered orthotic device includes an actuator assembly comprising a motor and a first portion of a transmission assembly that provides a speed reduction of a motor speed to an output speed; and a driven joint member comprising an output portion of the transmission assembly and a connector component for connecting the driven joint member to a brace component of the orthotic device. The driven joint member including the output portion of the transmission assembly is connected remotely from the actuator assembly by flexible cabling that runs between the actuator assembly and the driven joint member, to permit flexibility in positioning the driven joint member relative to the actuator assembly.

In exemplary embodiments, the actuator assembly includes a first stage of speed reduction of the transmission assembly connected to an output shaft of the motor for providing a speed reduction of the motor output; and an input portion of a second stage of speed reduction of the transmission assembly linked to an output of the first stage of speed reduction. The driven joint member comprises an output portion of the second stage of speed reduction of the transmission assembly for providing a speed reduction relative to the output of the first stage. The driven joint member including the output portion of the second stage is connected remotely from the actuator assembly by the flexible cabling to permit the flexibility in positioning the driven joint member relative to the actuator assembly.

In exemplary embodiments, the driven joint member includes a lateral cap and a medial cap, wherein the lateral cap is rotatable relative to a medial cap. The lateral cap includes a first attachment component that is connectable to a first brace component of the orthotic device, and the medial cap includes a second attachment component that is connectable to a second brace component of the orthotic device, whereby rotation of the lateral cap relative to the medial cap rotates the first attachment component relative to the second attachment component to operate a joint of the orthotic device. The medial cap includes a cable port for inserting flexible cabling into the driven joint member, and the lateral cap includes a cable slot that receives the flexible cabling from the cable port and anchors the flexible cabling within the cable pulley. The lateral cap may rotate relative to the medial cap about a radial bearing.

Another aspect of the invention is an orthotic device including an orthotic brace system and an actuator system according to any of the embodiments. The actuator assembly of the actuator system is attached remotely from the driven joint member, and the actuator assembly drives the driven joint member to act as a joint of the orthotic bracing system. The orthotic bracing system may be a KAFO device in which the driven joint member acts as the knee joint. The orthotic bracing system may be an HKAFO device in which a first driven joint member of a first actuator system acts as the knee joint, and/or a second driven joint member of a second actuator system acts as a hip joint.

In alternative embodiments, a joint control system may include a non-powered motion control unit configured as an intelligent damper or a lock, instead of driving the cables (and thus the orthotic joint) with a motor and through a powered actuator including a transmission. Movement of the cables may be controlled through damping via a friction brake or other damping source, such as a hydraulic piston and control valve. Alternatively, the motion control unit may include a locking mechanism, controlled by a friction clutch or a positive-engagement lock. A solenoid may be used in such cases to provide the locking. In the case of the damper or the lock mechanism, a transmission may still be employed to increase the effective holding force against cable motion. The damper or lock mechanism provides remote control of an orthotic joint through flexible cabling comparably as in the powered embodiments. Accordingly, the remote control performed by a joint control system may either be powered actuation, damping, or locking.

These and further features of the present invention will be apparent with reference to the following description and attached drawings. In the description and drawings, particular embodiments of the invention have been disclosed in detail as being indicative of some of the ways in which the principles of the invention may be employed, but it is understood that the invention is not limited correspondingly in scope.

<FIG> are drawings depicting various views of an exemplary actuator system <NUM> for use with an orthotic device, in accordance with embodiments of the present invention. The actuator system <NUM> includes an actuator assembly <NUM> that is housed within an actuator housing <NUM>, and a driven joint member <NUM>. The driven joint member <NUM> is remotely connected from the actuator assembly <NUM> by flexible cabling, which may be configured as a pair of Bowden cable sheaths <NUM> and <NUM> that include respective Bowden cables.

An aspect of the invention, therefore, is an enhanced actuator system for a powered orthotic device that may be incorporated into customized orthotic devices by remotely positioning the driven joint member from the actuator assembly via flexible cabling. In exemplary embodiments the actuator system includes an actuator assembly and a driven joint member. The driven joint member is connected remotely from the actuator assembly by flexible cabling to permit flexibility in positioning the driven joint member relative to the actuator assembly. The actuator system may include an actuator assembly having a motor and a first portion of a transmission assembly that provides a speed reduction of a motor speed to an output speed, and a driven joint member having an output portion of the transmission assembly and a connector component for connecting the driven joint member to a brace component of the orthotic device. The driven joint member including the output portion of the transmission assembly is connected remotely from the actuator assembly by flexible cabling that runs between the actuator assembly and the driven joint member, to permit flexibility in positioning the driven joint member relative to the actuator assembly.

In exemplary embodiments, the system is a powered actuator system in which a motor drives the joint member, by a speed reduction transmission system, which for example is a two-stage transmission. In such embodiments, the actuator assembly includes a first stage of speed reduction of the transmission assembly connected to an output shaft of the motor for providing a speed reduction of the motor output, and an input portion of a second stage of speed reduction of the transmission assembly linked to an output of the first stage of speed reduction. The driven joint member comprises an output portion of the second stage of speed reduction of the transmission assembly for providing a speed reduction relative to the output of the first stage. The driven joint member including the output portion of the second stage is connected remotely from the actuator assembly by the flexible cabling to permit the flexibility in positioning the driven joint member relative to the actuator assembly.

<FIG> is a drawing depicting an isometric view of the drive components of the actuator system of <FIG> in isolation. <FIG> is a drawing depicting a top view of the portion of the actuator system that includes the components as depicted in <FIG>. In these views, the actuator housing <NUM> is removed so as to depict the actuator assembly components. Generally, the actuator assembly components include a motor <NUM> and a transmission system <NUM> that operates to drive the joint member <NUM>. As described in more detail below, in exemplary embodiments the actuator assembly is configured as a high torque, low profile actuator with the motor <NUM> configured as a flat electric motor, and the transmission system <NUM> being configured as a two-stage speed reduction drive transmission. The two-stage transmission may include belt/chain/cable stages, with the output of the final stage and the driven joint member <NUM> being attached remotely from the first stage of the transmission through Bowden cable sheaths. In addition, the motor <NUM> may be a brushless DC motor.

To further illustrate the detailed components of the actuator assembly, <FIG> is a drawing depicting an isometric view of the actuator system <NUM> of <FIG>, with the actuator housing <NUM> and motor <NUM> removed to better illustrate the stages of the actuator transmission system <NUM>. <FIG> is a drawing depicting a top view of the actuator system as depicted in <FIG>. <FIG> is drawing depicting the transmission system <NUM> in isolation including the three stages of said transmission system.

Referring to <FIG>, in exemplary embodiments a first stage (and see particularly <FIG> and <FIG> as best depicting the first stage) of the transmission system <NUM> includes a relatively small diameter first sprocket <NUM> that is attached to an output shaft <NUM> of the flat profile brushless motor <NUM>. The first sprocket <NUM> thus receives the output shaft <NUM> of the motor. The small diameter sprocket <NUM> transmits power to a relatively large second sprocket <NUM> via a first transmission member <NUM> to form the first stage of speed reduction. In other words, for appropriate speed reduction a diameter of the second sprocket is larger than a diameter of the first sprocket. In this embodiment, the first transmission member <NUM> is configured as a chain that engages around the first and second sprockets.

As an alternative configuration of the first stage of the transmission system <NUM>, the first stage may be configured as a belt/pulley stage instead of a sprocket/chain stage. In such embodiment, the first stage of the transmission system <NUM> includes a relatively small diameter first stage pulley that is attached to an output shaft of the flat profile brushless motor <NUM>. The small diameter first stage pulley similarly transmits power to a relatively large larger diameter pulley, and in this embodiment the first transmission member is configured as a belt that engages around the two pulleys. The belt may be tensioned by spring loaded idlers located on opposite sides of the first pulley. Similarly as in the previous embodiment, for appropriate speed reduction a diameter of the second pulley is larger than a diameter of the first stage pulley.

For the second stage of speed reduction, an input portion of the second stage of speed reduction is linked to an output of the first stage of speed reduction. Generally, the input portion of the second stage includes a rotating member connected between the output of the first stage and the flexible cabling. The output portion of the second stage, which is incorporated into the driven joint member, includes a cable pulley that receives the flexible cabling. The cable pulley has a diameter larger than a diameter of the rotating member to form the second stage of speed reduction.

Referring to the figures, the relatively large diameter second sprocket <NUM> is the output of the first stage of speed reduction, and is attached to a shaft <NUM>. The shaft <NUM> is commonly attached to a rotating member, such as for example another relatively small diameter third sprocket <NUM> (seen best in the viewpoint of <FIG> and <FIG>). The third sprocket <NUM> acts as an input portion of the second stage of speed reduction that is linked to the output (second sprocket <NUM>) of the first stage of speed reduction. The teeth of the third sprocket <NUM> interact with a second roller chain <NUM> having opposing ends that are fitted with respective fittings <NUM> and <NUM>, which may be configured as crimp fittings. The crimp fittings <NUM> and <NUM> are attached to respective ends of the roller chain <NUM> and receive respective ends of transmission cable portions <NUM> and <NUM> to attach the first and second cable portions to the actuator assembly. The first and second transmission cable portions may be a single Bowden cable that extends around the joint member <NUM>, or may be two separate Bowden cables that have end portions that are anchored within the joint member <NUM>, as further detailed below. The crimp fittings <NUM> and <NUM> are crimped about the cable ends so as to provide a secure chain/cable connection of the Bowden cable portions to the actuator assembly. Although use of crimp fittings constitutes an exemplary embodiment, other configurations of fittings or connections <NUM> and <NUM> for the cable ends may be employed, such as for example swage fittings, welding, castings, and the like.

The transmission Bowden cable portions <NUM> and <NUM> are then routed through respective opposing Bowden cable sheaths <NUM> and <NUM>, and the transmission cable portions <NUM> and <NUM> are attached to a relatively large cable pulley <NUM> of the driven joint member <NUM> to form the output portion of the second stage of speed reduction. In other words, for appropriate speed reduction a diameter of the cable pulley <NUM> is larger than a diameter of the third sprocket <NUM>. In exemplary embodiments, cable portion <NUM> may be referred to as an extension cable portion <NUM> that winds around the cable pulley <NUM> during joint extension, and cable portion <NUM> may be referred to as a flexion cable portion <NUM> that winds around the cable pulley <NUM> during joint flexion. The driven joint member <NUM> is attached to the cable pulley <NUM> permanently, such as with a retaining compound or press fit configuration. Additional details regarding the configuration of the joint member <NUM> relative to the transmission cable portions <NUM> and <NUM> and cable pulley <NUM> are described below.

With such configuration, the actuator system <NUM> has a thin profile and is extremely lightweight relative to its output torque capability. Each stage of the two-stage transmission system is highly efficient and thus very little power is lost through the transmission system. Importantly, the transmission is also back-drivable, meaning that a torque applied at the output via the driven joint will cause the transmission, and ultimately the motor, to spin. This back-drivability is significant as it enables cooperative motion when worn by a user who is able to contribute some power via their own muscles. In an exemplary embodiment, the actuator system has a total transmission ratio of approximately <NUM>:<NUM>, and a maximum continuous torque of approximately <NUM>. With a weight of approximately <NUM> oz, the continuous torque-to-weight ratio of the actuator system in this embodiment is <NUM>/oz. Such parameters are highly suitable for operation in powered orthotic devices, including KAFO and HKAFO devices, as being wholly compatible with mobility assistance for walking.

The actuator assembly further may include integrated control electronics that are encompassed within the actuator housing. The control electronics may include a battery, sensors, and electronic circuit boards that control operation of the overall actuator system <NUM>. In exemplary embodiments in which the actuator assembly is driven by a brushless DC motor, magnets in proximity to or coupled to the motor shaft may be provided with embedded sensors to sense the motor shaft rotation. The sensing components may operate as a Hall-effect sensor with connections to processor circuitry in the control electronics to measure the motor operation, which in turn may be used to determine the resultant positioning of the driven joint member <NUM>. In this manner, accurate positioning of the joint member is achieved for precise controlling of the actuator system.

For added resistive torque beyond what the motor can provide, the second stage of the transmission system speed reduction further may include a braking element. To achieve this, an electric actuator (or actuators) engage a mechanical interference or friction lock to prevent motion of the second belt sprocket <NUM> (or belt pulley). To prevent damage to the transmission, the braking element may be allowed to slip above a certain torque level.

In the previous embodiments, a joint control system is configured having a control assembly that is a powered actuation system in which a motor initially provides the driving force that acts on the remote flexible cabling through a transmission. In alternative embodiments, a joint control system may be configured to include a non-powered motion control unit, which for example may be an intelligent damper or a lock, instead of driving the cables (and thus the orthotic joint) with a motor and through powered actuator including a transmission. Movement of the cables may be controlled by the motion control unit through damping via a friction brake or other damping source, such as a hydraulic piston and control valve. Alternatively, the motion control unit may include a locking mechanism, controlled by a friction clutch or a positive-engagement lock. A solenoid may be used in such cases to provide the locking. In the case of the damper or the lock mechanism, a transmission may still be employed to increase the effective holding force against cable motion. The damper or lock mechanism provides remote control of an orthotic joint through flexible cabling comparably as in the powered embodiments. Accordingly, the remote control by a joint control system may either be powered actuation, damping, or locking.

In exemplary embodiments, the driven joint member includes a cable pulley configuration comprising a lateral cap that is rotatable relative to a medial cap. The medial cap includes a cable port for inserting the flexible cabling into the cable pulley, and the lateral cap includes a cable slot that receives the flexible cabling from the cable port and anchors the flexible cabling within the cable pulley. Ends of the flexible cabling include an anchor fitting, such as a crimp fitting, and the crimp fitting is located within the cable slot in a manner that drives the rotation. The flexible cabling includes Bowden cable portions that are connected to the crimp fitting and routed from the crimp fitting in the cable slot through the cable slot. The lateral cap includes one or more range limiting tracks, and the medial cap includes one or more respective stop blocks, that extend into the range limiting track(s), wherein a rotation range of the lateral cap relative to the medial cap is limited by the range limiting track(s) interacting with the stop block(s).

<FIG> are drawings depicting various views of an exemplary configuration of the driven joint member <NUM>, which includes the output of the second stage of the transmission that includes the larger cable pulley referenced above. In particular, <FIG> is a drawing depicting an outer view of the exemplary driven joint member <NUM>, and <FIG> is a drawing depicting an inner view of the exemplary driven joint member. In this context, an outer view refers to a viewpoint from a side of the joint member that is visible during use, i.e., facing away from a user's body. An inner view refers to a viewpoint from a side of the joint member that is not visible during use, i.e., facing toward or against a user's body. <FIG> is a drawing depicting a first edge view of the exemplary driven joint member. <FIG> is a drawing depicting second edge view opposite from the first edge view of the exemplary driven joint member. The figures in this example depict a driven joint member associated with a right knee joint, although driven joint members associated with other body joints would be configured comparably.

The driven joint member <NUM> includes a lateral cap <NUM> that faces outward from the body during use (see <FIG>) and a medial cap <NUM> that faces against the body during use (see <FIG>). The lateral cap and the medial cap rotate relative to each other about a bearing structure <NUM> to form the larger cable pulley referenced above. The driven joint member <NUM> may be made from a variety of materials, depending on the strength requirements of the orthotic device or brace to which the actuation system is to be integrated. Steel, stainless steel, and aluminum are common material choices for orthotic joints and may be used in connection with described embodiments of the driven joint member <NUM>.

<FIG> further depict additional views of the lateral cap <NUM> in isolation of the driven joint member <NUM>. In particular, <FIG> is a drawing depicting an outer view of the lateral cap component of the exemplary driven joint member. <FIG> is a drawing depicting an inner view of the lateral cap component of the exemplary driven joint member. <FIG> is a drawing depicting a first edge view of the lateral cap component of the exemplary driven joint member. <FIG> is a drawing depicting a second edge view opposite from the first edge view of the lateral cap component exemplary driven joint member. The lateral cap <NUM> includes a lateral cap housing <NUM> that defines a cable slot <NUM> that receives the cable portions <NUM> and <NUM> as further detailed below. As shown particularly in the edge view of <FIG>, the lateral cap <NUM> has a fitting slot <NUM>. As relatedly shown in the edge view of <FIG> showing the full driven joint, a crimp fitting <NUM> is located within the fitting slot <NUM>. The crimp fitting <NUM> receives and secures the ends of the cable portions <NUM> and <NUM>. As referenced above, the cable portions <NUM> and <NUM> may comprise two different cables that are secured within the crimp fitting <NUM>, or the cable portions <NUM> and <NUM> may be opposite portions of a single cable that extends through the crimp fitting <NUM>. As the cable portions are pulled in the flexion or extension direction, the crimp fitting <NUM> operates as a driving mechanism that rotates the lateral cap <NUM> relative to the medial cap <NUM>.

As best depicted in <FIG>, the lateral cap housing <NUM> further defines a first range limiting track <NUM> and a second range limiting track <NUM> that cooperate with corresponding components of the medial cap <NUM> to limit the extension and flexion range of the joint member <NUM>. A third recess <NUM> may be cut away from the material of the lateral cap <NUM>, which provides for a degree of weight reduction of the lateral cap component. The lateral cap housing <NUM> further defines a bearing hole <NUM> that receives the radial bearing structure as further detailed below. The lateral cap <NUM> further includes a first attachment recess <NUM> (see e.g., <FIG> and <FIG>) that attaches to a joint bar that forms part of a bracing system of an orthotic device. For example, the first attachment recess <NUM> may be a lower attachment component that attaches to a first joint bar of an orthotic device.

<FIG> further depict additional views of the medical cap <NUM> in isolation of the driven joint member <NUM>. In particular, <FIG> is a drawing depicting an outer view of the medial cap component of the exemplary driven joint member. <FIG> is a drawing depicting an inner view of the medial cap component of the exemplary driven joint member. <FIG> is a drawing depicting a first edge view of the medial cap component of the exemplary driven joint member. <FIG> is a drawing depicting a second edge view opposite from the first edge view of the medial cap component exemplary driven joint member. The medial cap <NUM> includes a medial cap housing <NUM> that defines a first sheath receiver <NUM> that receives the first Bowden cable sheath <NUM> including the extension cable portion <NUM>, and a second sheath receiver <NUM> that receives the second Bowden cable sheath <NUM> including the flexion cable portion <NUM>. The cable portions extend through the respective sheath receivers and into the cable slot <NUM> of the lateral cap. The medial cap <NUM> further includes a first stop block <NUM> that extends into the first range limiting track <NUM> of the lateral cap <NUM>, and a second stop block <NUM> that extends into the second first range limiting track <NUM> of the lateral cap <NUM>. The medial cap <NUM> further includes a circular post <NUM> about which the radial bearing <NUM> is positioned.

Accordingly, when the lateral cap <NUM> and medial cap <NUM> are joined together, the radial bearing structure <NUM> is positioned within the bearing hole <NUM> between the surface of the lateral cap <NUM> that defines the bearing hole <NUM> and the circular post <NUM>. The medial cap <NUM> further includes a second attachment recess <NUM> (see, e.g., <FIG> and <FIG>) that attaches to another joint bar of an orthotic device. For example, the second attachment recess <NUM> may be an upper attachment component that attaches to a second joint bar that also forms part of the bracing system of an orthotic device. The first and second attachment recesses are positioned offset relative to each other, which enables the first and second attachment recesses to rotate past each other.

<FIG> is a drawing depicting an exploded view of the exemplary driven joint member <NUM>. Like components are identified with like references numerals in <FIG> as in the previous joint member figures to provide additional illustration of the pertinent components. <FIG> in addition illustrates details as to the operation of the bearing structure <NUM>. The bearing structure <NUM> is configured as a radial bearing that accommodates radial loads as the lateral cap rotates relative to the medial cap. The driven joint member <NUM> further includes a thrust bearing <NUM> that is fixed between the lateral cap <NUM> and the medial cap <NUM>. The thrust bearing <NUM> is configured as a ring structure that accommodates laterals loads as may occur during abduction and adduction relative to the joint. The thrust bearing <NUM> may be made of a polytetrafluoroethylene (PTFE) material such as Teflon® or the like. The driven joint member further may include a thrust washer <NUM> located on an opposite side of the medial cap relative to thrust bearing <NUM>. The thrust washer <NUM> also may be made of PTFE or like material and cooperates with the thrust bearing to accommodate lateral loads.

The driven joint member <NUM> further may include a washer <NUM>, such as a metal washer, and a fastener element <NUM>, such as a bolt or screw. The fastener extends through the medial cap <NUM> and is anchored into the lateral cap <NUM> on the inner side of the lateral cap. Accordingly, the fastener <NUM> rotates in conjunction with the rotation of the lateral cap and relative to the medial cap.

<FIG> is a drawing depicting the exemplary driven joint member in an operational configuration. The driven joint member <NUM> operates as follows. As referenced above and described in connection with <FIG>, at a first end cable portions <NUM> and <NUM> are inserted into crimp fittings <NUM> and <NUM>, and the crimp fittings <NUM> and <NUM> are crimped about the cable ends so as to provide a secure chain/cable connection with the roller chain <NUM> of the input portion of the second transmission stage. The transmission cable portions <NUM> and <NUM> are then routed through respective opposing Bowden cable sheaths <NUM> and <NUM>, and the transmission cable portions <NUM> and <NUM> are attached to a relatively larger cable pulley to form the output portion of the second stage of speed reduction. The larger cable pulley is formed of the lateral cap <NUM> and medial cap <NUM>. The cable portions <NUM> and <NUM> extend through the cable slot <NUM> formed around the lateral cap <NUM>, and at second ends opposite from the first ends, the extension cable portion <NUM> and flexion cable portion <NUM> are inserted into the additional crimp fitting <NUM> which secures the second ends of the cable portions <NUM> and <NUM>. The crimp fitting <NUM> anchors the cable portions within the cable pulley stage formed by the lateral cap and medial cap. Similarly as with the cable ends at the input portion of the second stage, use of a crimp fitting <NUM> constitutes an exemplary embodiment, and other configurations of fittings or connections for the cable portion ends may be employed, such as for example swage fittings, welding, castings, and the like.

The motor shaft speed of the motor <NUM> is reduced through the transmission system <NUM> as described above. The lateral cap <NUM> and medial cap <NUM> cooperatively act as the cable reel output of the transmission system. Generally, because the cable fitting <NUM> is wider as compared to the cable slot <NUM>, drawing one of the cable portions will cause the lateral cap <NUM> to be rotated relative to the medial cap <NUM> by a driving action of the crimp fitting <NUM> in a direction depending on the direction of rotation, the crimp fitting <NUM> driving against the surface that defines the cable slot <NUM>.

Accordingly, for extension the extension cable portion <NUM> is drawn by rotation of the third sprocket <NUM> such that the lateral cap <NUM> rotates counter-clockwise relative to the medial cap <NUM> about the radial bearing <NUM>, which swings the first attachment recess <NUM> in the counter-clockwise direction. An orthotic joint component that is connected to the first attachment recess would rotate commensurately. For example, if the first attachment recess <NUM> is connected to a joint bar of the knee joint in a KAFO (or HKAFO) device being worn by a user, the user's knee will extend. Alternatively or additionally, if the first attachment recess <NUM> is connected to a joint bar of the hip joint in an HKAFO device being worn by a user, the user's hip will extend. Similarly, for flexion the flexion cable portion <NUM> is drawn by rotation of the third sprocket <NUM> such that the lateral cap <NUM> rotates clockwise relative to the medial cap <NUM> about the radial bearing <NUM>, which swings the first attachment recess <NUM> in the clockwise direction. If the first attachment recess <NUM> is connected to a joint bar of the knee joint in a KAFO (or HKAFO) device being worn by a user, the user's knee will flex. Alternatively or additionally, if the first attachment recess <NUM> is connected to a joint bar of the hip joint in an HKAFO device being worn by a user, the user's hip will flex.

As referenced above, the offset positioning of the first attachment recess <NUM> and second attachment recess <NUM> permits the attachment recesses to be rotated past each other, which permits a wide range of motion. In practice, the range of motion is limited by the first range limiting track <NUM> sliding relative to the first stop block <NUM>, and the second range limiting track <NUM> sliding relative to the second stop block <NUM>, as the lateral cap <NUM> rotates relative to the medial cap <NUM>. In other words, the stop blocks <NUM> and <NUM> abutting up against either end of the respective range limiting tracks <NUM> and <NUM> will preclude additional rotation in the given direction. In the depicted embodiments as illustrative, the range of motion is from <NUM>° extension to <NUM>° of flexion, although larger ranges including even up to and beyond <NUM>° of total rotation are possible by re-configuring the range limiting tracks and stop blocks to accommodate any desired rotational limit.

Because the driven joint member <NUM> is actuated remotely via the flexible cabling from the rest of the actuator system <NUM>, and remotely from the actuator assembly <NUM> in particular, the output stage of the transmission system is not required to be axially parallel to the other transmission stages. The use of flexible cabling routed through cable sheaths permits a degree of flexibility in positioning the driven joint member <NUM> relative to the actuator assembly <NUM>. This allows the full assembly to bend around the contours of the human form, such as the transitions from the thigh to the knee to the lower leg. The driven joint member can be mounted at the joint to be actuated, while keeping the remaining bulk of the actuator system out of the area of movement of the driven joint member. In application, the actuator system would be fastened to any suitable orthosis, which in typical configurations are constructed using standard <NUM>/<NUM>" x <NUM>/<NUM>" stainless steel or aluminum bars for mounting points at each joint, actuating the knee and/or hip on one or both legs.

<FIG> is a drawing depicting an exemplary knee-ankle-foot orthotic (KAFO) device <NUM>, which incorporates the actuator system <NUM> in accordance with embodiments of the present invention. The actuator system <NUM> may be incorporated into essentially any conventional KAFO device. As is typical, the KAFO device <NUM> includes an ankle-foot orthosis <NUM> including a foot plate <NUM> and an ankle support <NUM> that can receive the foot of the user (typically including a shoe). The foot plate <NUM> may operate with a pressure sensor that can detect when the foot plate is on or off of the ground to aid in the gait control. The pressure sensor may be incorporated as part of the foot plate <NUM>, or provided as a separate component that comes in contact with the foot plate <NUM>, for pressure sensing. The pressure sensor may be wired or wirelessly connected to the control electronics of the actuator assembly. The KAFO device <NUM> further includes a leg brace <NUM> that includes a calf support <NUM> and a thigh support <NUM> that wrap around a user's leg. Such components may be secured to the user using straps that are retained with any suitable mechanical fasteners, such as Velcro®. The leg brace <NUM> connects the components to each other by arranging the components on a frame <NUM>, typically made of metal such as for example steel, stainless steel, or aluminum. The referenced components form an orthotic brace to provide support for a user during walking.

Generally, the connector component of the driven joint member includes the first attachment recess that is connectable to a first brace component of the orthotic device, and a second attachment recess that is connectable to a second brace component of the orthotic device, whereby operation of the driven joint member rotates the first attachment recess relative to the second attachment recess to operate a joint of the orthotic device. In the example of a KAFO device, the actuator system <NUM> operates as a powered knee joint. The actuator system <NUM> is attached with the actuator assembly <NUM> mounted to the thigh support <NUM>. The cable sheaths <NUM> and <NUM> extend downward to the driven joint member <NUM>. The frame <NUM> includes a first joint bar <NUM> that extends downward from the thigh support <NUM>, and a second joint bar <NUM> that extends upward from the calf support <NUM>. The actuator system <NUM> further is connected to the brace components by connecting the first joint bar <NUM> of the frame to the second attachment recess <NUM> (not visible in this view) of the driven joint member <NUM>, and by connecting the second joint bar <NUM> of the frame to the first attachment recess <NUM> of the driven joint member <NUM> such that the driven joint member <NUM> is positioned at the user's knee during use. As referenced above, the use of Bowden cables routed through cable sheaths permits a degree of flexibility in positioning that allows the full assembly to bend around the contours of the leg. In operation, the actuator assembly drives the driven joint member as described above to provide extension and flexion of the user's knee joint.

<FIG> is a drawing depicting an exemplary hip-knee-ankle-foot orthotic (HKAFO) device <NUM>, which incorporates a first actuator system <NUM> and a second actuator system <NUM>' in accordance with embodiments of the present invention. Similarly as above, the actuator systems <NUM> and <NUM>' may be incorporated into essentially any conventional HKAFO device. As is typical, the HKAFO device generally includes the components of the KAFO device described above. The HKAFO device <NUM> further includes a torso support <NUM> that wraps around a user's torso. The torso support <NUM> also may be secured to the user using straps that are retained with any suitable mechanical fasteners, such as Velcro®. The referenced components form an orthotic brace with added torso support to provide support for a user during walking. In addition, in the example of <FIG>, the HKAFO device is a unilateral support device including brace components only for one leg (the right leg in this example). In other exemplary embodiments, a bilateral HKAFO device may be provided in which comparable brace components are provided for both legs.

In the example of an HKAFO device, the first actuator system <NUM> is positioned and operates as a powered knee joint in the manner described above for the KAFO device. In addition, the second actuator system <NUM>' is positioned and operates as a powered hip joint. The second actuator system <NUM>' is attached with the actuator assembly <NUM>' mounted to the torso support <NUM>. The cable sheaths <NUM>' and <NUM>' extend downward to the driven joint <NUM>'. The frame <NUM> further includes a third joint bar <NUM> that extends downward from the torso support <NUM>, and a fourth joint bar <NUM> that extends upward from the thigh support <NUM>. The actuator system <NUM>' further is connected to the brace components by connecting the third joint bar <NUM> of the frame to the second attachment recess <NUM>' (not visible in this view) of the driven joint member <NUM>', and by connecting the fourth joint bar <NUM> of the frame to the first attachment recess <NUM>' of the driven joint member <NUM>' such that the driven point member <NUM>' is positioned at the user's hip during use. As referenced above, the use of Bowden cables routed through cable sheaths again permits a degree of flexibility in positioning that allows the full assembly to bend around the contours of the leg. In operation, the first and second actuator assemblies respectively drive both the driven joint members as described above to provide extension and flexion of the user's knee and hip joints. In addition, although the example HKAFO device <NUM> includes both powered knee and hip joints, one or the other of powered hip versus knee joints may be employed with the HKAFO brace configuration.

The use of the described actuation system has advantages over conventional configurations in that the actuator system can be readily integrated with standard orthotic bracing that is customized to a user body type. Such actuation system provides a smaller and lighter solution for powering wearable orthotic systems, which should also require less torque that is more suitable for orthotic devices. The actuator system configurations address the deficiencies of conventional configurations by minimizing the size of the driven joint, and by allowing the actuator assembly drive unit to be located remotely relative to the driven joint, transmitting power via flexible Bowden cables. With such configuration, varus and valgus angling at the human knee joint and/or hip abduction/adduction in the frontal plane are optimized for walking. The Bowden cable/sheaths configuration of the output of the transmission system permits locating the driven joint member remotely from drive motor and the first transmission stage. This permits the referenced degree of flexibility in positioning the driven joint member so that the actuator system may be integrated into a wide range of customizable orthotic devices, i.e., the actuator system is suitable for use with any standard type bracing as fitted to a given user without the need for additional customization of the actuator system itself.

The actuator system also is back-drivable, meaning that a torque applied at the output driven joint member will cause the transmission, and ultimately the motor, to spin. This back-drivability is significant as it enables cooperative motion when worn by a user who is able to contribute some power for walking via their own muscles. By permitting user contribution to the walking power, the user experiences health benefits of muscle strengthening and ultimately an enhanced gait, characterized by a smoother gait motion and higher efficiency.

As referenced above, in alternative embodiments, a joint control system may include a non-powered motion control unit configured as an intelligent damper or a lock, instead of driving the cables (and thus the orthotic joint) with a motor and through a powered actuator including a transmission. Movement of the cables may be controlled by the motion control unit through damping via a friction brake or other damping source, such as a hydraulic piston and control valve. Alternatively, the motion control unit may include a locking mechanism, controlled by a friction clutch or a positive-engagement lock. A solenoid may be used in such cases to provide the locking. In the case of the damper or the lock mechanism, a transmission may still be employed to increase the effective holding force against cable motion. The damper or lock mechanism provides remote control of an orthotic joint through flexible cabling comparably as in the powered embodiments. Accordingly, the remote control by a joint control system may either be powered actuation, damping, or locking.

An aspect of the invention, therefore, is an enhanced actuator system for an orthotic device that may be incorporated into customized orthotic devices by remotely positioning the driven joint member from the actuator assembly via flexible cabling. In exemplary embodiments, the actuator system includes an actuator assembly and a driven joint member. The actuator assembly includes a motor and a first portion of a transmission assembly that provides a speed reduction of a motor speed to an output speed. The driven joint member includes an output portion of the transmission assembly and a connector component for connecting the driven joint member to a brace component of the orthotic device. The driven joint member including the output portion of the transmission assembly is connected remotely from the actuator assembly by flexible cabling that runs between the actuator assembly and the driven joint member, to permit flexibility in positioning the driven joint member relative to the actuator assembly. The actuator system may include one or more of the following features, either individually or in combination.

In an exemplary embodiment of the actuator system, the driven joint member comprises a lateral cap that is rotatable relative to a medial cap.

In an exemplary embodiment of the actuator system, the lateral cap rotates relative to the medial cap about a radial bearing.

In an exemplary embodiment of the actuator system, the actuator system further includes a thrust bearing configured as a ring positioned between the lateral cap and the medial cap.

In an exemplary embodiment of the actuator system, the actuator system further includes a thrust washer located on an opposite side of the medial cap relative to the thrust bearing.

In an exemplary embodiment of the actuator system, the lateral cap includes a range limiting track and the medial cap includes a stop block that extends into the range limiting track, wherein a rotation of the lateral cap relative to the medial cap is limited by the range limiting track interacting with the stop block.

In an exemplary embodiment of the actuator system, the lateral cap includes a first range limiting track and a second range limiting track, and the medial cap includes a first stop block and a second stop that extend respectively into the first and second range limiting tracks, wherein a rotation of the lateral cap relative to the medial cap is limited by the range limiting tracks interacting with the stop blocks.

In an exemplary embodiment of the actuator system, the lateral cap includes a first attachment recess that is connectable to a first brace component of the orthotic device, and the medial cap includes a second attachment recess that is connectable to a second brace component of the orthotic device, whereby rotation of the lateral cap relative to the medial cap rotates the first attachment recess relative to the second attachment recess to operate a joint of the orthotic device.

In an exemplary embodiment of the actuator system, the actuator system further includes a fastener that extends through the medical cap and is anchored within the lateral cap, wherein the fastener rotates in conjunction with the lateral cap and relative to the medial cap.

In an exemplary embodiment of the actuator system, the medial cap includes a cable port for inserting the flexible cabling into the driven joint member, and the lateral cap includes a cable slot that receives the flexible cabling from the cable port.

In an exemplary embodiment of the actuator system, the flexible cabling extends within the cable slot around the lateral cap and a portion of the flexible cabling are fixed within a fitting located within the lateral cap, and wherein the fitting operates as a driving member that drives rotation of the lateral cap relative to the medial cap.

In an exemplary embodiment of the actuator system, the actuator assembly comprises: a first stage of speed reduction of the transmission assembly connected to an output shaft of the motor for providing a speed reduction of the motor output; and an input portion of a second stage of speed reduction of the transmission assembly linked to an output of the first stage of speed reduction. The driven joint member comprises an output portion of the second stage of speed reduction of the transmission assembly for providing a speed reduction relative to the output of the first stage. The driven joint member including the output portion of the second stage is connected remotely from the actuator assembly by the flexible cabling to permit the flexibility in positioning the driven joint member relative to the actuator assembly.

In an exemplary embodiment of the actuator system, the input portion of the second stage includes a rotating member connected between the output of the first stage and the flexible cabling; the output portion of the second stage includes a cable pulley that receives the flexible cabling; and the cable pulley has a diameter larger than a diameter of the rotating member to form the second stage of speed reduction.

In an exemplary embodiment of the actuator system, the flexible cabling comprises at least one cable that is routed through a cable sheath.

In an exemplary embodiment of the actuator system, the flexible cabling comprises a first cable that is routed through a first cable sheath, and a second cable that is routed through a second cable sheath, wherein the cable sheaths are connected at opposite ends to the actuator assembly and the driven joint member.

In an exemplary embodiment of the actuator system, a first fitting connects a first end of the at least one cable to the actuator assembly, and a second fitting connects an opposing end of the at least one cable.

In an exemplary embodiment of the actuator system, the transmission assembly includes a sprocket and a roller chain that interacts with teeth of the sprocket, and the first and second fittings are located on respective ends of the roller chain to connect the at least one cable to the roller chain.

In an exemplary embodiment of the actuator system, the first stage of speed reduction comprises a first rotating member attached to the output shaft of the motor that transmits power to a second rotating member via a first transmission member, and the second rotating member has a diameter larger than a diameter of the first rotating member to form the first stage of speed reduction.

In an exemplary embodiment of the actuator system, the first transmission member is a chain, and the first and second rotating members are sprockets.

In an exemplary embodiment of the actuator system, the connector component of the driven joint member includes a first attachment recess that is connectable to a first brace component of the orthotic device and a second attachment recess that is connectable to a second brace component of the orthotic device, whereby operation of the driven joint member rotates the first attachment recess relative to the second attachment recess to operate a joint of the orthotic device.

In an exemplary embodiment of the actuator system, the first attachment recess and the second attachment recess are positioned offset relative to each other to enable the first and second attachment recesses to rotate past each other.

Another aspect of the invention is a driven joint member for use as a joint of an orthotic device. In exemplary embodiments, the joint member includes a lateral cap and a medial cap, wherein: the lateral cap is rotatable relative to a medial cap; the lateral cap includes a first attachment component that is connectable to a first brace component of the orthotic device, and the medial cap includes a second attachment component that is connectable to a second brace component of the orthotic device, whereby rotation of the lateral cap relative to the medial cap rotates the first attachment component relative to the second attachment component to operate a joint of the orthotic device; and the medial cap includes a cable port for inserting flexible cabling into the driven joint member, and the lateral cap includes a cable slot that receives the flexible cabling from the cable port and anchors the flexible cabling within the cable pulley. The driven joint member may include one or more of the following features, either individually or in combination.

In an exemplary embodiment of the driven joint member, the lateral cap rotates relative to the medial cap about a radial bearing.

In an exemplary embodiment of the driven joint member, the driven joint member further includes a thrust bearing configured as a ring positioned between the lateral cap and the medial cap.

In an exemplary embodiment of the driven joint member, the driven joint member further includes a thrust washer located on an opposite side of the medial cap relative to the thrust bearing.

In an exemplary embodiment of the driven joint member, the lateral cap includes a range limiting track and the medial cap includes a stop block that extends into the range limiting track, wherein a rotation of the lateral cap relative to the medial cap is limited by the range limiting track interacting with the stop block.

In an exemplary embodiment of the driven joint member, the lateral cap includes a first range limiting track and a second range limiting track, and the medial cap includes a first stop block and a second stop that extend respectively into the first and second range limiting tracks, wherein a rotation of the lateral cap relative to the medial cap is limited by the range limiting tracks interacting with the stop blocks.

In an exemplary embodiment of the driven joint member, the lateral cap includes a first attachment recess that is connectable to a first brace component of the orthotic device, and the medial cap includes a second attachment recess that is connectable to a second brace component of the orthotic device, whereby rotation of the lateral cap relative to the medial cap rotates the first attachment recess relative to the second attachment recess to operate a joint of the orthotic device.

In an exemplary embodiment of the driven joint member, the driven joint member further includes a fastener that extends through the medical cap and is anchored within the lateral cap, wherein the fastener rotates in conjunction with the lateral cap and relative to the medial cap.

In an exemplary embodiment of the driven joint member, the medial cap includes a cable port for inserting the flexible cabling into the driven joint member, and the lateral cap includes a cable slot that receives the flexible cabling from the cable port.

Claim 1:
An actuator system (<NUM>) for a wearable orthotic device, the actuator system (<NUM>) comprising:
a transmission assembly (<NUM>);
an actuator assembly (<NUM>) comprising a motor (<NUM>) and a first portion (<NUM>, <NUM>) of the transmission assembly (<NUM>) that provides a speed reduction of a motor speed to an output speed;
a driven joint member (<NUM>; <NUM>) comprising an output portion (<NUM>) of the transmission assembly (<NUM>) and a connector component (<NUM>, <NUM>) for connecting the driven joint member (<NUM>; <NUM>) to a brace component of the orthotic device, wherein the connector component (<NUM>, <NUM>) of the driven joint member (<NUM>; <NUM>) includes a first attachment recess (<NUM>) that is connectable to a first brace component of the orthotic device and a second attachment recess (<NUM>) that is connectable to a second brace component of the orthotic device, whereby operation of the driven joint member (<NUM>; <NUM>) rotates the first attachment recess relative (<NUM>) to the second attachment recess (<NUM>) to operate a joint of the orthotic device;
flexible cabling (<NUM>, <NUM>) that connects the driven joint member (<NUM>; <NUM>) to the actuator assembly (<NUM>), wherein the driven joint member (<NUM>; <NUM>) including the output portion of the transmission assembly is connected remotely from the actuator assembly by the flexible cabling (<NUM>; <NUM>) that runs between the actuator assembly (<NUM>) and the driven joint member (<NUM>; <NUM>), to permit flexibility in positioning the driven joint member (<NUM>; <NUM>) relative to the actuator assembly (<NUM>); and
a housing (<NUM>) that houses the actuator assembly;
wherein the actuator system is configured to be worn by a user and wherein the flexibility in positioning the driven joint member (<NUM>; <NUM>) relative to the actuator assembly is such that knee varus and valgus angling and/or hip abduction/adduction in a frontal plane can be optimized for walking.