Prosthetic foot with an adjustable ankle and method Number:7,520,904 from the United States Patent and Trademark Office (PTO) owispatent

Title: Prosthetic foot with an adjustable ankle and method

Abstract: A prosthetic foot with an adjustable ankle includes an upper portion coupled to a socket of an amputee. A lower portion is adjustably coupled to the upper portion, and is attached to a foot member with heel and toe sections. A movable coupling is disposed between the upper and lower portions, and includes a displacement member slidably coupled to a displacement track. The movable coupling allows the toe section to pivot downward and the heel section to simultaneously displace forward. The adjustable ankle can be adjusted with an actuator coupled to a tractor bolt coupled between the upper and lower portions. A sensor is associated with the upper portion or the lower portion to sense frequency of contact, force of contact, or orientation of the upper portion or the lower portion, and to output a corresponding output signal.

Patent Number: 7,520,904 Issued on 04/21/2009 to Christensen

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Inventors:	Christensen; Roland J. (Fayette, UT)
Assignee:	Freedom Innovations, LLC (Irvine, CA)
Appl. No.:	11/254,621
Filed:	October 19, 2005

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Related U.S. Patent Documents

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	Application Number	Filing Date	Patent Number	Issue Date
	10970679	Oct., 2004	7462201
	10690941	Oct., 2003	6966933

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Current U.S. Class:	623/47 ; 623/24
Current International Class:	A61F 2/64 (20060101); A61F 2/48 (20060101)
Field of Search:	623/24,47-56 318/568.12

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Primary Examiner: Snow; Bruce E
Attorney, Agent or Firm: Thorpe North & Western

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Parent Case Text

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This is a continuation-in-part application of U.S. application Ser. No. 10/970,679, filed Oct. 20, 2004, now U.S. Pat. No. 7,462,201 which is a continuation-in-part of U.S. application Ser. No. 10/690,941, filed Oct. 21, 2003 now U.S. Pat. No. 6,966,933.

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Claims

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What is claimed is:

1. An adjustable ankle device for a prosthetic foot, comprising: a) an upper portion configured to be coupled to a socket of an amputee; b) a lower portion, adjustably coupled to the upper portion, configured to be attached to a foot member; c) a movable coupling, disposed between the upper and lower portions, having an arcuate projection slidable in an arcuate slot oriented fore and aft with the arcuate projection having a shape corresponding to the arcuate slot, and defining an arcuate displacement path, such that the projection is constrained to slide fore and aft along the arcuate movement path, to restrict movement to: i) simultaneously in a downward and forward direction in which the lower portion simultaneously pivots downward and displaces forward relative to the upper portion; and ii) simultaneously in a rearward and upward direction in which the lower portion simultaneously pivots upward and displaces rearward relative to the upper portion; d) an actuator, coupled to the movable coupling, to move the upper and lower portions with respect to one another; e) a sensor, associated with the upper or lower portions, to sense frequency of contact, force of contact, or orientation of the upper portion or the lower portion, and to output a corresponding output signal; and f) a controller, coupled to the actuator and the sensor, to process the output signal of the sensor and engage the actuator in response to the output signal.

2. A device in accordance with claim 1, wherein the controller automatically drives the actuator to move the lower portion to a predetermined initial position in response to a predetermined signal from the sensor.

3. A device in accordance with claim 1, wherein the controller further comprises: a user input interface, configured to allow a user to program the controller to adjust the lower portion to a position corresponding to changes in slope.

4. A device in accordance with claim 1, wherein the controller has a walk mode to respond to a relatively lower frequency and force of impact on the lower portion, and a run mode to respond to a relatively higher frequency and force of impact on the lower portion.

5. A device in accordance with claim 1, wherein the controller has: i) a downhill mode to move the lower portion to a forward and downward position corresponding to walking downhill; ii) an uphill mode to move the lower portion to a rearward and upward position corresponding to walking up hill; and iii) a level mode to move the lower portion to a relatively level position for walking on relatively level terrain.

6. A device in accordance with claim 1, further comprising: means for a user to manually control the actuator.

7. A device in accordance with claim 1, wherein the lower portion is constrained to fore and aft arcuate displacement with respect to the upper portion between at least two fixed positions, including: a) a low position, in which the heel section is disposed at a lower elevational position, and in which the heel section is disposed in a rearward position; and b) a high position, in which the heel section is disposed at a higher elevational position, and in which the heel section is disposed in a forward position.

8. A device in accordance with claim 1, wherein the arcuate slot has a T-shaped cross-sectional shape; and wherein the arcuate projection has a T-shaped cross-sectional shape.

9. A device in accordance with claim 1, wherein the arcuate slot includes an enlarged cavity and wherein the arcuate projection includes an enlarged head.

10. A prosthetic foot device with an adjustable ankle, comprising: a) an attachment member configured to be coupled to a socket of an amputee; b) a foot member, coupled to and adjustable with respect to the attachment member with an enlarged head of an arcuate projection slidable within a corresponding shaped enlarged cavity of an arcuate slot, and being constrained to fore and aft arcuate displacement with respect to the upper portion, simultaneously in: i) a downward and forward direction in which the toe section pivots downward and the heel portion simultaneously displaces forward with respect to the attachment member; and ii) a rearward and upward direction in which the toe section pivots upward and the heel portion simultaneously displaces rearward with respect to the attachment member; c) an actuator, operatively coupled to the attachment member and the foot member, to move the attachment member and the foot member with respect to one another; d) a sensor, associated with the attachment member or the foot member, to sense frequency of contact, force of contact, or orientation of the attachment member or the foot member, and to output a corresponding output signal; and e) a controller, coupled to the actuator and the sensor, to process the output signal of the sensor and engage the actuator in response to the output signal.

11. A device in accordance with claim 10, wherein the controller automatically drives the actuator to move the foot member to a predetermined initial position in response to a predetermined signal from the sensor.

12. A device in accordance with claim 10, wherein the controller further comprises: a user input interface, configured to allow a user to program the controller to adjust the foot member to a position corresponding to changes in slope.

13. A device in accordance with claim 10, wherein the controller has a walk mode to respond to a relatively lower frequency and force of impact on the foot member, and a run mode to respond to a relatively higher frequency and force of impact on the foot member.

14. A device in accordance with claim 10, wherein the controller has: i) a downhill mode to move the foot member to a forward and downward position corresponding to walking down hill; ii) an uphill mode to move the foot member to a rearward and upward position corresponding to walking up hill; and iii) a level mode to move the foot member to a relatively level position for walking on relatively level terrain.

15. A device in accordance with claim 10, further comprising: means for a user to manually control the actuator.

16. A device in accordance with claim 10, wherein the foot member is constrained to fore and aft arcuate displacement with respect to the attachment member between at least two fixed positions, including: a) a low position, in which the heel section is disposed at a lower elevational position, and in which the heel section is disposed in a rearward position; and b) a high position, in which the heel section is disposed at a higher elevational position, and in which the heel section is disposed in a forward position.

17. A device in accordance with claim 10, wherein the arcuate slot has a T-shaped cross-sectional shape; and wherein the arcuate projection has a T-shaped cross-sectional shape.

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Description

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BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a prosthetic foot with an adjustable ankle. More particularly, the present invention relates to a prosthetic foot that simultaneously pivots downward and displaces forward.

2. Related Art

Many individuals have lost a limb for various reasons including war, accident, or disease. In most instances these individuals are not only able to live relatively normal lives, but physically active lives as well. Oftentimes, these individuals are aided in their everyday lives by a prosthetic limb. The objective of prosthesis is to provide an artificial limb that simulates the function and natural feel of the replaced limb.

With respect to prosthetic feet, the development of a functional and natural artificial foot has been limited only by material and imagination. Many designs have attempted to copy the anatomy of the foot or simulate its actions by replacing the bones and muscle with various mechanical components. Other designs have departed radically from mere anatomical copying or mechanical simulation by replacing the entire foot with an energy storage element such as a spring. As the user steps onto the foot, the user's weight compresses the spring. As the user moves forward, the user's weight comes off the foot and the energy stored in the spring is used to propel the user forward.

Almost all of the past designs have focused on the major aspect of the prosthetic foot--movement of the ankle or foot as it relates to walking or running. Few designs consider the use of the foot with different shoes, such as different heel heights. For example, some shoes, such as sneakers, have a generally level or horizontally flat platform, while other shoes, such as high-heels or boots, have a heel that is relatively elevated with respect to the toe. It will be appreciated that the ankle of a natural foot pivots to accommodate different heels. In a natural foot, the foot and toes rotate to conform to the slope of the terrain. The artificial foot of previous designs usually incorporates a unitary foot that is incapable of such movement at the ankle.

Some artificial feet have a dynamic pivot or hinge at the ankle, or a dynamic ankle joint. See U.S. Pat. Nos. 4,442,554; 5,482,513 and 5,913,902. During use, a foot member often pivots or swings up and down about a pivot or axle.

Some artificial feet have an adjustable ankle with a swivel connection, or a foot that pivots at the ankle. For example, see U.S. Pat. Nos. 5,800,564 and 6,402,790. Such feet often have a foot member that selectively pivots about a pivot.

Other feet have a foot member that adjusts linearly back and forth. For example, see U.S. Pat. No. 6,228,124.

One problem with some of the above configurations is that they have proved unsatisfactory in use with different types of shoes, such as shoes with different heel heights. Another problem with some of the above configurations is that they are complicated or difficult to adjust.

SUMMARY OF THE INVENTION

It has been recognized that it would be advantageous to develop a prosthetic foot with an adjustable ankle. In addition it has been recognized that it would be advantageous to develop a prosthetic foot that provides a more natural feel or use when used with different shoes, such as shoes with different heel heights.

The invention provides an adjustable ankle device for a prosthetic foot. The adjustable ankle includes a lower portion adjustably coupled to an upper portion. The upper portion is coupled to a socket of an amputee. The lower portion is attached to a foot member that can have heel and toe sections. A movable coupling is disposed between the upper and lower portions. The movable coupling has a projection slidable in an arcuate slot oriented fore and aft, and defines an arcuate displacement path, such that the projection is constrained to slide fore and aft along the arcuate movement path.

In accordance with a more detailed aspect of the present invention, the adjustable ankle further comprises an actuator coupled to the movable coupling to move the upper and lower portions with respect to one another. A sensor is associated with the upper portion or the lower portion to sense frequency of contact, force of contact, or orientation of the upper portion or the lower portion, and to output a corresponding output signal. A controller is coupled to the actuator and the sensor to process the output signal of the sensor and engage the actuator in response to the output signal.

In accordance with a more detailed aspect of the present invention, the lower portion moves: 1) simultaneously in a downward and forward direction in which the lower portion simultaneously pivots downward and displaces forward with respect to the upper portion; and 2) simultaneously in a rearward and upward direction in which the lower portion simultaneously pivots upward and displaces rearward with respect to the upper portion. In addition, the lower portion is pivotal and displaceable with respect to the upper portion between at least two fixed positions, including: 1) a low position configured to dispose the heel section at a lower elevational position, and to dispose the heel section in a rearward position; and 2) a high position configured to dispose the heel section at a higher elevational position, and to dispose the heel section in a forward position.

In accordance with a more detailed aspect of the present invention, a tractor bolt can be rotatably disposed between the upper and lower portions, and driven by a motor. In addition, a level sensor can sense the orientation of the upper portion, and can send a signal to the motor to adjust the ankle automatically to level the foot or vertically orient the upper portion.

Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a prosthetic foot with an adjustable ankle in accordance with an embodiment of the present invention;

FIG. 2a is a side view of the prosthetic foot with an adjustable ankle of FIG. 1, shown in a first, lower position;

FIG. 2b is a side view of the prosthetic foot with an adjustable ankle of FIG. 1, shown in a second, higher position;

FIG. 3 is an exploded view of the adjustable ankle of FIG. 1;

FIG. 4 is a cross-sectional view of an upper portion of the adjustable ankle of FIG. 3;

FIG. 5 is a front view of the upper portion of the adjustable ankle of FIG. 3;

FIG. 6 is a perspective view of a lower portion of the adjustable ankle of FIG. 3;

FIG. 7 is a partial side view of another adjustable ankle in accordance with an embodiment of the present invention;

FIG. 8 is a side schematic view of a prosthetic foot with an adjustable ankle in accordance with the prior art;

FIG. 9 is a side view of another adjustable ankle in accordance with an embodiment of the present invention;

FIG. 10 is a side view of another adjustable ankle in accordance with an embodiment of the present invention;

FIG. 11 is a perspective view of another adjustable ankle in accordance with an embodiment of the present invention;

FIG. 12 is a side view of the adjustable ankle of FIG. 11;

FIG. 13 is a perspective view of another adjustable ankle in accordance with an embodiment of the present invention;

FIG. 14 is a side view of the adjustable ankle of FIG. 13;

FIG. 15 is a perspective view of another prosthetic foot with the adjustable ankle of FIG. 13 in accordance with an embodiment of the present invention; and

FIG. 16 is a side view of the prosthetic foot of FIG. 15.

DETAILED DESCRIPTION

Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

As illustrated in FIGS. 1-6, a prosthetic foot, indicated generally at 10, with an adjustable ankle, indicated generally at 14, in accordance with the present invention is shown for adjusting the prosthetic foot. The adjustable ankle 14 can adjust the angle of the foot 10, and the elevation of the heel. The adjustable ankle 14 can be utilized to quickly and easily adjust the foot 10 for use with different shoes, such as shoes with different heel heights. As described in greater detail below, the prosthetic foot 10 and adjustable ankle 14 allow the prosthetic foot to adjust by simultaneously pivoting downward and displacing forward. Thus, as a toe section pivots downward to accommodate a higher heel, the foot or heel also displaces forwardly. Surprisingly, it has been found that such a configuration provides a more natural feel.

The prosthetic foot 10 can have various different configurations. For example, the foot 10 can include one or more foot members 18 adjustably attached to an attachment member 22 by the adjustable ankle 14. Thus, the adjustable ankle 14 can be coupled between the attachment member 22 and the foot members 18. The attachment member 22 can be operatively coupled to a socket that receives an amputee's stump, as is known in the art. For example, the attachment member can include an inverted frustopyramidal boss 26 that can be received in a corresponding cavity (not shown), as is known in the art. Such inverted frustopyramidal type connections are typically used to selectively connect a prosthetic foot to the socket in a desired orientation, and can be used to adjust the angle between the foot and the socket. The boss 26 is held within a socket by a plurality of set screws, and is thus difficult to quickly adjust.

The foot members 18 can have various different members with various different configurations. For example, the foot members 18 can include a forefoot 30 that extends between a heel section 34 at a rear of the foot and a toe section 38 at a toe location of a natural foot. In addition, the foot members 18 can include a footplate 42 extending substantially the length of the foot between a heel section 46 at a heel location of a natural foot and a toe section 50 at the toe location. The toe section 50 of the footplate 42 can be attached to the toe section 38 of the forefoot 30. The foot members 30 and 42 can be flexible and resilient energy storing members that act as springs to bend or flex during use. The foot members 30 and 42 can include a composite material, such as a carbon or graphite fiber in an epoxy matrix.

The adjustable ankle 14 can include upper and lower portions 54 and 58 adjustably coupled to one another. The upper portion 54 can be coupled to the socket or attachment member 22. The upper portion 54 and attachment member 22 can be integrally formed, and the upper portion 54 can form part of the attachment member 22. The lower portion 58 can be coupled to the foot member 18 or forefoot 30.

A movable coupling is disposed between the upper and lower portions. The movable coupling allows the lower portion to move: 1) simultaneously in a downward and forward direction in which the lower portion simultaneously pivots downward and displaces forward with respect to the upper portion; and 2) simultaneously in a rearward and upward direction in which the lower portion simultaneously pivots upward and displaces rearward with respect to the upper portion. In addition, the lower portion is pivotal and displaceable with respect to the upper portion between at least two fixed positions, including: 1) a low position (FIG. 2a) configured to dispose the heel section at a lower elevational position, and to dispose the prosthetic foot or heel section in a rearward position; and 2) a high position (FIG. 2b) configured to dispose the heel section at a higher elevational position, and to dispose the prosthetic foot or heel section in a forward position.

The coupling can be oriented upright with respect to the lower portion 58, with one end of the coupling being disposed at a lower elevation with respect to a central section of the coupling. The movable coupling can include a displacement member slidable in a displacement track disposed between the upper and lower portions. The lower portion is movable from a rearward position to a forward and downward position, with the toe section pivoted downwardly and the heel section displaced forwardly. The movable coupling can include an arched coupling 62 formed or disposed between the upper and lower portions 54 and 58. The arched coupling 62 forms an arc that is oriented upright, with at least one end of the arched coupling or arc being disposed at a lower elevation with respect to a central section of the arched coupling. The arched coupling 62 includes an arcuate projection 66 slidable in an arcuate slot 70. The arcuate projection 66 can be or can form at least a portion of the lower portion 58, and thus can extend from the foot member 18 or forefoot 30. The arcuate slot 70 can be formed in the upper portion 54 or the attachment member 22. The arcuate projection 66 and arcuate slot 70 also have an upright orientation, as described above.

The arched coupling 62 (and the arcuate projection and slot 66 and 70) allows the arcuate projection 66 (and the lower portion 58 and foot portion 18) to both 1) pivot downward and 2) displace forward. Thus, the toe section 38 pivots downward and the heel section 34 simultaneously displaces forward (indicated by arrow 74 in FIG. 2b) with respect to the attachment member 22. Similarly, the arcuate projection 66 can both 1) pivot upward and 2) displace rearward. Thus, the toe section 38 pivots upward and the heel section 34 simultaneously displaces rearward (indicated by arrow 78 in FIG. 2a) with respect to the attachment member.

The foot member 18 is pivotal and displaceable between at least two positions, including 1) a low position and 2) a high position, as shown in FIGS. 2a and 2b. In the low position (FIG. 2a), the toe section 38 of the foot member 18 is pivoted in an upward direction 78 with respect to the arched coupling 62 (or attachment section 22). Thus, the heel section 34 (of attachment section 22) is disposed at a relatively lower elevational position h1 with respect to the high position (FIG. 2b). The low position can be used with flatter shoes, such as sneakers, flats, loafers and the like. In addition, the foot member 18 or heel section 34 is disposed in a rearward position, indicated by solid lines in FIG. 2a. In the low position, the forefoot 18 not only pivots upward, but displaces rearward so that the heel section 34, represented by d.

In the high position (FIG. 2b), the toe section 38 of the foot member 18 is pivoted in a downward direction 74 with respect to the arched coupling 62 (or attachment section 22). Thus, the heel section 34 (or attachment section 22) is disposed at a higher elevational position h2 with respect to the low position (FIG. 2a). Thus, the high position can be used with more elevated shoes, such as high heels, cowboy boots and the like. In addition, the foot member 18 or heel section 34 is disposed in a forward position, shown in solid lines, indicated by solid lines in FIG. 2b, as opposed to a rearward position. In the high position, the foot member 18 not only pivots downward, but displaces forward so that the heel section 34 is in a forward position, represented by d. Surprisingly, it has been found that as the elevation of the attachment section 22 is increased, a more forward position of the foot member 18 or heel section 34 provides a more natural feel. It will be appreciated that a simple pivot adjustment causes the foot to move rearward as it pivots downward, as shown in FIG. 8.

As stated above, the arcuate slot 70 can be formed in the attachment section 22 or upper portion 54 of the arched coupling 62. The arcuate slot 70 can have an upper wall 80 that is arcuate or curved. In addition, the arcuate slot 70 can include an enlarged cavity 84 and a narrower gap 88. The enlarged cavity 84 is arcuate or curved. The narrower gap 88 can extend from a bottom of the upper portion 54 to the enlarged cavity 84. The arcuate slot 70 can have a T-shaped cross-sec