Patent Description:
Various types of prosthetic devices are available as artificial substitutes for a missing body part, such as an arm or leg. Prosthetic joints are also available as substitutes for human joints, such as an ankle or knee. Prosthetic joints can include actuators to create motion of the joint, such as to adjust a heel height of the prosthetic foot.

<CIT> discloses a linear actuator with two screws extending from opposite ends, threadably engaged with a rotating elongate nut. An elongate magnet is coupled to the nut and surrounded by a stator with coils. Rotation of the nut axially moves the screws together or apart, and the screw thread pitch can be chosen to improve self-locking.

The present invention relates to an actuator as set out in claim <NUM>-<NUM> and to a prosthetic foot comprising such an actuator as set out in claims <NUM>-<NUM>.

These and other features, aspects, and advantages of the present disclosure are described with reference to the drawings of certain embodiments, which are intended to schematically illustrate certain embodiments and not to limit the disclosure.

<FIG> illustrate an example embodiment of an actuator or adjustment mechanism <NUM>. In some embodiments, the actuator <NUM> can be incorporated into a prosthetic joint, for example, a prosthetic ankle. As shown in the exploded views of <FIG>, in the illustrated embodiment, the actuator <NUM> includes an upper component <NUM>, a lower component <NUM>, and a central component <NUM>. As also shown in <FIG>, the upper component <NUM> includes an upper connector <NUM> and an outer housing <NUM>. As also shown in <FIG>, the lower component <NUM> includes a lower connector <NUM> and an optional outer housing or bellows <NUM>. The upper <NUM> and lower <NUM> connectors extend from opposite ends of the actuator <NUM>. In some embodiments, the upper <NUM> and lower <NUM> connectors are ball joint rod end bearings. The upper connector <NUM> has a ball joint 110a. at one end of the upper connector <NUM> and a threaded shaft <NUM> (shown in <FIG>) extending between the ball joint 110a and a distal end 110b at an opposite end of the upper connector <NUM>. The lower connector <NUM> has a ball joint 112a at one end of the lower connector <NUM> and a threaded shaft <NUM> (shown in <FIG>) extending between the ball joint 112a and a proximal end 112b at an opposite end of the lower connector <NUM>. The ball joints 110a, 112a are oriented at the top and bottom, respectively, of the actuator <NUM>, and the ends 110b, 112b are disposed opposite each other along a longitudinal axis (e.g., central axis or symmetrical axis) of the actuator <NUM>. In one embodiment, one of the connectors <NUM>, <NUM> can have clockwise threads while the other of the connectors <NUM>, <NUM> can have counter-clockwise threads.

As shown in <FIG>, the outer housing <NUM> of the upper component <NUM> is hollow, cylindrical or generally cylindrical, and disposed around at least a portion of the upper connector <NUM>, for example, around the threaded shaft <NUM>. The outer housing <NUM> can be integrally formed with or attached to the upper connector <NUM>. For example, the outer housing <NUM> can be attached to the upper connector <NUM> just below the ball joint 110a. With continued reference to <FIG>, the threaded shaft <NUM> of the upper connector <NUM> can extend through the outer housing <NUM> such that a circumferential annulus <NUM> is defined between an inner surface of the outer housing <NUM> and a threaded surface of the upper connector <NUM>.

As shown in <FIG>, in the illustrated embodiment, the central component <NUM> has an outer shell <NUM> and an inner shaft <NUM>. In the illustrated embodiment, the outer shell <NUM> has a base <NUM> and a cylindrical shaft <NUM>. The inner shaft <NUM> is disposed within and can be permanently or removably coupled to the outer shell <NUM>. In the illustrated embodiment, the base <NUM> is generally circular. However, the shape of the base is not limiting. For example, the base can have a triangular or polygonshaped perimeter, or have other shapes. The base <NUM> can be attached or positioned distal to the cylindrical shaft <NUM>. For example, the base <NUM> can be attached to and/or positioned adjacent a distal end of the shaft <NUM>. In some embodiments, an inner surface of the base <NUM> has a recess <NUM> (as shown in, for example, <FIG>). As shown in <FIG>, a top portion <NUM> of the optional outer housing <NUM> of the lower component <NUM> is disposed in the recess <NUM>. As shown in <FIG>, at least a portion of the inner shaft <NUM> is internally threaded. In the illustrated embodiment, the inner shaft <NUM> includes an upper internally threaded portion 135a and a lower internally threaded portion 135b. In some embodiments, the central component <NUM> can be a single component without a separate outer shell <NUM> and inner shaft <NUM>.

Returning to <FIG>, the internally threaded inner shaft <NUM> receives and threadedly engages the threaded shafts <NUM>, <NUM> (see <FIG>, <FIG>) of the upper connector <NUM> and the lower connector <NUM>, respectively. For example, in the illustrated embodiment, the upper internally threaded portion 135a (shown in <FIG>) threadedly engages the threaded shaft <NUM> of the upper connector <NUM>, and the lower internally threaded portion 135b (shown in <FIG>) threadedly engages the threaded shaft <NUM> of the lower connector <NUM>. The cylindrical shaft <NUM> of the central component <NUM> is at least partially disposed within the circumferential annulus <NUM> in the upper component <NUM> between the outer housing <NUM> and the threaded shaft <NUM> of the upper connector <NUM>. In use, the central component <NUM> can be rotated to adjust a height or length of the actuator <NUM>. Rotation of the central component <NUM> is translated into linear motion of the connectors <NUM>, <NUM> and causes the distance between the ends 110b, 112b of the connectors <NUM>, <NUM> to increase or decrease, depending on the direction of rotation of the central component <NUM>.

With continued reference to <FIG>, in some embodiments, the inner shaft <NUM> can have a tab <NUM> extending outwardly from an upper end of the inner shaft <NUM>. The tab <NUM> can act as a travel limit during assembly and/or use. As shown in <FIG> (in which the outer shell <NUM> is removed for clarity), the tab <NUM>, or a portion of the upper end of the inner shaft <NUM> including the tab <NUM>, has a larger diameter than an inner surface of a lower portion 121a of the outer housing <NUM>. An inner surface of an upper portion 121b of the outer housing <NUM> can have a larger diameter than the inner surface of the lower portion 121a to accommodate the tab <NUM>. The inner surface of the lower portion 121a of the outer housing <NUM> can include a groove or channel <NUM>. During assembly, the groove or channel <NUM> accommodates the tab <NUM> and allows the tab <NUM>, and therefore the central component <NUM>, to move upwards into the outer housing <NUM> of the upper component <NUM>. During use, the tab <NUM> no longer aligns with the groove or channel <NUM>. If the central component <NUM> is rotated relative to the upper component <NUM>, for example, to adjust a height of the actuator as described herein, such that the central component <NUM> moves away from the upper component <NUM>, the central component <NUM> can rotate relative to the upper component <NUM> until the tab <NUM> contacts an upper ledge <NUM> of the lower portion 121a of the outer housing <NUM>. The upper ledge <NUM> has an internal diameter configured to prevent the tab <NUM> from moving further away from the upper component <NUM>. The tab <NUM>', contacting the upper ledge <NUM> therefore acts as a stop such that the upper and central components <NUM>, <NUM> cannot be unscrewed from each other beyond a certain extent. In other embodiments, the outer housing <NUM> can comprise a plurality of components instead of or in addition to the groove/channel <NUM> for assembly purposes, which will be described in greater detail below.

Returning to <FIG>, the outer housing <NUM> of the upper component <NUM> includes one or more magnets <NUM>. The outer housing <NUM> can include one or more longitudinally or axially extending grooves, channels, or apertures <NUM>, for example as shown in <FIG> and <FIG>. Each of the channels <NUM> can receive and contain a cylindrical or bar magnet <NUM>. In the illustrated embodiment, the outer housing <NUM> includes three magnets <NUM>, as shown in <FIG>. The upper component <NUM> can include an end cap <NUM> coupled to an end of the outer housing <NUM> nearest the end 110b of the connector <NUM> or away from the ball joint 110a, for example as shown in <FIG> and <FIG>, to help hold and secure the magnets <NUM> within the outer housing <NUM>. As shown in <FIG>, the central component <NUM>, for example, the cylindrical shaft <NUM> of the outer shell <NUM>. , includes one or more corresponding cylindrical or bar magnets. The cylindrical shaft <NUM> can itself be formed of one or more magnets or can include one or more magnets attached to the cylindrical shaft <NUM>. For example, in the illustrated embodiment, the cylindrical shaft <NUM> includes a plurality of adjacent bar magnets <NUM> disposed around an outer perimeter or surface of the cylindrical shaft <NUM>. Although in the illustrated embodiment the magnets <NUM> extend around the entirety of the cylindrical shaft <NUM> and are adjacent one another, in other embodiments the magnets <NUM> may extend around only a portion of the cylindrical shaft <NUM> and/or may be spaced from each other. Additionally, in some embodiments, the cylindrical shaft <NUM> and/or magnet <NUM> can be a single piece of material that may be magnetized in steps to have different polarities as described below.

The magnets <NUM> in the outer housing <NUM> and magnets <NUM> on the cylindrical shaft <NUM> can have opposing poles such that the magnets attract each other. When the central component <NUM> is rotated relative to the outer housing <NUM> such that the magnets <NUM> in the central component <NUM> are aligned with the magnets <NUM> in the outer housing <NUM>, the attraction between the magnets locks or substantially locks the position of the central component <NUM> relative to the outer housing <NUM> and therefore locks or substantially locks the height or length of the actuator <NUM>. If desired, a user can overcome the magnetic force between the magnets to rotate the central component <NUM> relative to the outer housing <NUM> and adjust the height of the actuator <NUM> (e.g., by rotating the central component <NUM> relative to the upper component <NUM> with a rotational force that is higher than the magnetic force between the magnets).

In the illustrated embodiment, adjacent magnets <NUM> in the central component <NUM> have alternating polarities. In some embodiments, instead of a plurality of adjacent magnets <NUM>, the cylindrical shaft <NUM> and/or a magnet coupled to and/or disposed around the cylindrical shaft <NUM> can be a single piece of material that is magnetized in steps to form a plurality of adjacent sections of different, e.g., alternating, polarities. The magnets <NUM> in the upper component <NUM> can have split polarities. For example, as shown in <FIG>, half 122a of each magnet <NUM> can have one polarity and the other half 122b of each magnet <NUM> can have the opposite polarity. The central component <NUM> can be rotated relative to the upper component <NUM> such that the magnets <NUM> in the upper component <NUM> are aligned with magnets <NUM> in the central component <NUM> of the same or opposing polarity. The attraction between magnets <NUM> and magnets <NUM> of opposing polarity can be overcome by the user physically rotating the central component <NUM>. The user can therefore rotate the central component <NUM> to adjust the distance between the connectors <NUM>, <NUM> and therefore the height or length of the actuator <NUM>. Once the desired height is achieved, the user can lock the actuator <NUM> by, if needed, slightly further rotating the central component <NUM> until the magnets <NUM> are aligned with the nearest magnets <NUM> of opposing polarity. In some embodiments, the base <NUM> can include one or more markings <NUM>, some or all of which may be labeled (e.g., with letters A and B in <FIG>). In the illustrated embodiment, markings <NUM> are disposed around the entirety circumference of the base <NUM> at even intervals; however, in other embodiments, the markings <NUM> may have unequal spacing, the marks <NUM> may not extend around the entirety of the circumference of the base <NUM>, and/or the base <NUM> may include more or fewer markings <NUM> than shown. The outer housing <NUM> of the upper component <NUM> can include one or more markings <NUM>, for example as shown in <FIG>. The markings <NUM> and <NUM> can be arranged and configured such that alignment of marking(s) <NUM> with a specific marking (or specific markings) <NUM> indicates a locked or unlocked position of the actuator <NUM>. Additionally or alternatively, in some embodiments, the markings <NUM> and/or <NUM> can be arranged and configured such that alignment of marking(s) <NUM> with a specific marking (or specific markings) <NUM> indicates a height of the actuator <NUM>.

In some embodiments, the actuator <NUM> includes or acts as a stepper magnet. The central component <NUM> can be rotated among discrete locations or positions to adjust the length of the actuator <NUM>, thereby, for example, adjusting the heel height of a prosthetic foot that incorporates the actuator <NUM>. When the central component <NUM> is positioned in one of the discrete locations, attraction between the magnets <NUM>, <NUM> holds the rotational position of the central component <NUM> in a locked position.

<FIG> illustrate another embodiment of an actuator or adjustment mechanism <NUM> having the same or similar features as the actuator <NUM> of <FIG> except as described herein. Reference numerals of same or similar components of the actuators <NUM> and <NUM> have the same last two digits. Accordingly, features of the actuator <NUM> can be incorporated into features of the actuator <NUM> and features of the actuator <NUM> can be incorporated into features of the actuator <NUM>.

In the illustrated embodiment, as shown in <FIG>, the upper ledge <NUM> can be formed by a component (e.g., a ring or washer in the illustrated embodiment) that is separately formed from a main body of the outer housing <NUM>. The outer housing main body can have an inner diameter that can accommodate the tab <NUM> and can allow the tab <NUM>, and therefore the central component <NUM>, to move upwards into the outer housing <NUM> during assembly. The washer forming the upper ledge <NUM> and the end cap <NUM> of the outer housing <NUM> can be advanced into the outer housing <NUM> following the advancement of the central component <NUM>. An inner surface of a lower portion 1321a of the outer housing <NUM> can have a larger diameter than the inner surface of an upper portion 1321b of the outer housing <NUM> as shown. When assembled, the end cap <NUM> and the washer forming the upper ledge <NUM> are disposed within the lower portion 1321a of the outer housing <NUM>. The washer forming the upper ledge <NUM> can optionally be sandwiched between the end cap <NUM> and a lower ledge <NUM> of the upper portion 1321b. As shown, the washer forming the upper ledge <NUM> has an inner diameter that is smaller than the diameter of the inner surface of the upper portion 1321b. During use, the upper ledge <NUM> can act as a stopper for the tab <NUM> as described herein.

In the embodiment of <FIG>, the base <NUM> can have markings <NUM> of a different kind than those shown in <FIG>. As shown in <FIG>, the markings <NUM> can be numbers. The number and type of markings shown are for exemplary purposes only and are not limiting. Instead of or in addition to the markings <NUM>, the actuator <NUM> can have markings indicative of the height of the actuator <NUM> and/or the travel of the actuator <NUM> during adjustment. For example, markings indicative of height can be located on an outer surface of the cylindrical shaft <NUM> or an outer surface of the optional outer housing <NUM>, or on both the outer surfaces of the cylindrical shaft <NUM> and optional outer housing <NUM>. The locations of the markings indicative of height described are not limiting. Non-limiting examples of the markings indicative of height can be at least one of scales, numbers, symbols, or the like. The markings can advantageously allow reproducibility of height settings. The actuator <NUM> can also include such markings, for example, on the shaft <NUM> and/or the outer housing <NUM>, indicative of the height and/or travel of the actuator <NUM>. In the illustrated embodiment, the cylindrical shaft <NUM> and/or magnet <NUM> is a single piece of material that may be magnetized in steps to have different polarities as described above.

Also as shown in <FIG>, the optional outer housing <NUM> can have a substantially smooth outer surface instead of ridges (e.g., bellows) on an outer surface of the optional outer housing <NUM> as shown in <FIG>. The optional outer housing <NUM> does not have a top portion that can be retained in the recess <NUM> of the base <NUM> of the central component <NUM>. Instead, as shown in <FIG>, the recess <NUM> can accommodate an O-ring <NUM> fitted on the outer surface of the optional outer housing <NUM>, thereby retaining the optional outer housing <NUM>. The O-ring <NUM> allows the lower component <NUM> to independently rotate relative to the central component <NUM> to adjust the height of the adapter <NUM>.

In some embodiments, the actuator <NUM>, <NUM> can be used in a prosthetic joint. For example, a prosthetic ankle incorporating the actuator <NUM> is shown in the example embodiments of <FIG>. As shown, a prosthetic ankle module <NUM> incorporating the actuator <NUM> can include an upper attachment portion <NUM> and a lower attachment portion <NUM>. The upper connector <NUM>, e.g., the ball joint 1310a of the upper connector <NUM>, is coupled to the upper attachment portion <NUM>, and the lower connector <NUM>, e.g., the ball joint 1312a of the lower connector <NUM>, is coupled to the lower attachment portion <NUM>. <FIG> illustrates an example embodiment of a prosthetic foot <NUM> incorporating the ankle module <NUM>. <FIG> illustrates another example embodiment of a prosthetic foot <NUM> incorporating the ankle module <NUM> and disposed in a cosmesis <NUM>. The actuator <NUM> can be incorporated in the ankle module <NUM> and/or the prosthetic foot <NUM> in the same or a similar manner as the actuator <NUM>. Additional examples of incorporating an actuator into a prosthetic foot for heel height adjustment purposes are illustrated in <CIT> and entitled "PROSTHETIC FOOT WITH REMOVABLE FLEXIBLE MEMBERS," which serves a background to the present invention.

In the illustrated embodiment, the prosthetic foot <NUM> includes an upper foot member <NUM>, an intermediate foot member <NUM>, and a lower foot member <NUM>. In the illustrated embodiment, the lower foot member <NUM> extends from a heel end to a toe end, the upper foot member <NUM> is L-shaped, the intermediate foot member <NUM> is generally straight, and the intermediate <NUM> and upper <NUM> foot members extend from proximal ends to distal ends that are proximal of the toe end of the lower foot member <NUM>. However, other numbers and configurations of foot members are also possible, and the ankle module <NUM> can be adapted for use with other arrangements of foot members. For example, the upper foot member <NUM> can be C-shaped. The lower foot member <NUM> may not extend to a toe end, and the upper <NUM> or intermediate <NUM> foot member may instead extend to a toe end. In some embodiments, the prosthetic foot <NUM> may only include an upper foot member <NUM> and a lower foot member <NUM>.

In the illustrated embodiments, the upper attachment portion <NUM> has three connection portions or points <NUM>, <NUM>, <NUM>. The first connection portion <NUM> attaches the ankle module <NUM> to a user or another prosthetic device. In the illustrated embodiment, the first connection portion is a pyramid connector, although other connectors and adapters are also possible. The upper connector ball joint 1310a connects to the upper attachment portion <NUM> at the second connection point <NUM> rotatably or non-rotatably. The upper attachment portion <NUM> connects to the proximal end of the upper foot member <NUM> at the third connection portion <NUM>. In the illustrated embodiment, a brace <NUM> is attached, pivotably or non-pivotably, to the upper attachment portion <NUM> at the third connection portion <NUM>, and the upper foot member <NUM> is coupled to the brace <NUM>. The upper foot member <NUM> can be secured to the brace <NUM> via one or more fasteners <NUM>, such as one or more screws. In an embodiment in which the prosthetic foot <NUM> only includes an upper foot member <NUM> and a lower foot member <NUM>, the ankle module <NUM> can be modified such that the third <NUM> connection portion couples to the upper foot member <NUM>. In the illustrated embodiment, the third connection portion <NUM> is in a front portion of the upper attachment portion <NUM>, and the second connection portion <NUM> is in a rear portion of the upper attachment portion <NUM>. Therefore, the actuator <NUM> is located at a rear portion of the ankle module <NUM>. However, in other embodiments the actuator <NUM> can be positioned in a front portion of the ankle module <NUM>.

In the illustrated embodiment, the lower attachment portion <NUM> couples to the proximal end of the intermediate foot member <NUM>. The intermediate foot member <NUM> can be secured to the lower attachment portion <NUM> via one or more fasteners <NUM>, such as one or more screws. The lower attachment portion also couples to the lower connector <NUM>, either rotatably or non-rotatably, at a fourth connection portion <NUM>.

Claim 1:
An actuator (<NUM>) for a prosthetic or orthotic device, the actuator comprising:
a first component (<NUM>) having one or more magnets (<NUM>);
a second component (<NUM>) having one or more magnets (<NUM>), wherein a position of the second component (<NUM>) is adjustable relative to the first component (<NUM>) to adjust a length of the actuator (<NUM>), wherein
the second component (<NUM>) is sized to extend into an opening in the first component (<NUM>);
characterised in that when at least one magnet (<NUM>) or at least a portion of at least one magnet (<NUM>) in the first component (<NUM>) having a first polarity is aligned with at least one magnet (<NUM>) or at least a portion of at least one magnet (<NUM>) in the second component (<NUM>) having a second polarity opposite to the first polarity, a position of the second component (<NUM>) is substantially fixed relative to the first component (<NUM>), substantially locking the actuator;
in that when the at least one magnet (<NUM>) or at least a portion of at least one magnet (<NUM>) in the first component (<NUM>) is not aligned with the at least one magnet (<NUM>) or at least a portion of at least one magnet (<NUM>) in the second component (<NUM>), said position of the second component (<NUM>) is adjustable relative to the first component (<NUM>) to adjust said length of the actuator (<NUM>).