Lanyard suspension system for a prosthetic limb

A lanyard suspension system for a prosthetic limb that includes: (a) a lanyard cord adapted to extend from a distal end of a patient's residual limb; and (b) a lanyard lock assembly adapted to be seated at a distal end of a patient's prosthetic limb socket assembly. The lanyard lock assembly includes: (1) a lanyard lock base having a lanyard cord channel extending therethrough from an inlet hole in a proximal surface of the lanyard lock base to an outlet hole in one of a side surface and a distal surface of the lanyard lock base; and (2) a locking mechanism designed to allow the lanyard cord to substantially freely thread through the lanyard cord channel from the inlet hole to the outlet hole while substantially inhibiting the lanyard cord from threading in the opposite direction when in an active setting.

BACKGROUND

The present invention relates to a lanyard suspension system for a prosthetic limb; and, more specifically, a lanyard suspension system that may have a lower profile and may be less complicated than other known lanyard suspensions systems.

SUMMARY

The present invention is directed to a lanyard suspension system for a prosthetic limb socket assembly, and components thereof, and methods associated therewith. The lanyard suspension system includes a low-profile locking device adapted to be received within a distal end of a patient's outer prosthetic limb socket. The locking device includes an inlet hole on a proximal surface thereof for receiving the lanyard cord extending from a distal end of an inner, flexible socket worn on a patient's residual limb. The cord is threaded through the locking device and emerges out from an outlet hole of the locking device, and in turn, through an adjacent hole in the outer socket. The locking device is designed to allow the cord to freely thread through the locking device in a first direction—the direction that will pull the patient's residual limb into the outer socket—and is designed to substantially inhibit or lock the cord from threading through the locking device in the opposite direction. This cord locking function greatly assists the patient in donning the outer socket, especially when the residual limb is not easily entirely received within the outer socket (i.e., needs a lot of shifting and adjustment during the donning process).

The locking device includes a release button or mechanism that, when activated, allows the cord to be threaded in both directions, thereby allowing the residual limb to be removed again from the outer socket.

When the residual limb is pulled into the outer socket using the lanyard system, a cord retraction mechanism is provided to wind-up and store the excess lanyard cord extending out from the outer socket within a housing or on a reel, such that the excess cord is conveniently stored therewithin. In the exemplary embodiment, the cord retraction mechanism is a spring loaded winding/reel mechanism similar to an ordinary tape-measure device.

Therefore it is a first aspect of the present invention to provide a lanyard suspension system for a prosthetic limb that includes: (a) a lanyard cord adapted to extend from a distal end of a patient's residual limb; and (b) a lanyard lock assembly adapted to be seated at a distal end of a patient's prosthetic limb socket assembly. The lanyard lock assembly includes: (1) a lanyard lock base having a lanyard cord channel extending therethrough from an inlet hole in a proximal surface of the lanyard lock base to an outlet hole in one of a side surface and a distal surface of the lanyard lock base, where the lanyard cord channel is adapted to receive the lanyard cord extending therethrough; and (2) a locking mechanism designed to allow the lanyard cord to substantially freely thread through the lanyard cord channel from the inlet hole to the outlet hole while substantially inhibiting the lanyard cord to thread in the opposite direction when in an active setting and designed to allow the lanyard cord to freely thread through the lanyard cord channel in both directions when in an inactive setting. In this first aspect, the locking mechanism utilizes at least one biased jaw for engaging with the lanyard cord in the cord channel when the lanyard cord is pulled in the opposite direction in the active setting.

In a more detailed embodiment, the locking mechanism is biased to the active setting. In a further detailed embodiment, the lanyard lock assembly includes a manually actuated release button operatively coupled to the locking mechanism for allowing manual manipulation of the locking mechanism from the active setting to the inactive setting.

Alternatively, the lanyard cord channel includes a lock engaging segment having at least one wall; the biased jaw is a pivotable jaw having at least one tooth adapted to be biased into the lock engaging segment of the lanyard cord channel and against the at least one wall when the locking mechanism is in the active setting, and the pivotable jaw being pivoted so that the at least one tooth moves away from the at least one wall when the locking mechanism is manipulated to the inactive setting; and the at least one tooth is adapted to engage the lanyard cord and press the lanyard cord against the at least one wall in the active setting. In a more detailed embodiment, the pivotable jaw is sized and positioned such the at least one tooth may not be pivoted in the direction of the bias beyond the at least one wall, but is substantially freely pivotable in the opposing direction, against the direction of bias. The lanyard lock assembly may include a manually actuated release button operatively coupled to the pivotable jaw, and the pivotable jaw is pivoted so that the at least one tooth moves away from the at least one wall when the release button is actuated.

In an alternate detailed embodiment of the first aspect of the present invention, the lanyard suspension system further includes (c) a means for retaining slack lanyard cord extending out through the outlet hole. In a further detailed embodiment, the retaining means is located within the lanyard lock base. In yet a further detailed embodiment, the retaining means includes a feed hole for receiving slack lanyard cord; and the lanyard suspension system further comprises (d) a lanyard cord feed-through component adapted to be seated within or to a wall of the patient's prosthetic limb socket assembly adjacent to the outlet hole and the feed hole, where the feed-through component includes: (i) an outlet channel extending from an interior side of the feed-through component to an exterior side of the feed-through component, (ii) an inlet channel extending from an exterior side of the feed-through component to an interior side of the feed-through component, and (iii) a tab extending from the exterior side of the feed-through component in between the inlet channel and the outlet channel, where the tab is adapted to seat a segment of the lanyard cord extending between the inlet channel and outlet channel thereon. With this, a user may grip the segment of the lanyard cord seated on the tab.

It is a second aspect of the present invention to provide a lanyard suspension system for a prosthetic limb that includes: (a) a lanyard cord adapted to extend from a distal end of a patient's residual limb; and (b) a lanyard lock assembly adapted to be coupled to a prosthetic limb assembly. The lanyard lock assembly includes: (1) a lanyard lock base having a lanyard cord channel extending therethrough from an inlet hole of the lanyard lock base to an outlet hole of the lanyard lock base, where the lanyard cord channel is adapted to receive the lanyard cord extending therethrough; and (2) a lanyard cord retraction mechanism including a spool for winding slack lanyard cord extending out through the outlet hole of the lanyard lock base thereabout. In a further detailed embodiment, the spool is biased to rotate in a rotational direction that causes the slack lanyard cord to be wound into the spool.

In an alternate detailed embodiment of the second aspect of the present invention, the lanyard cord retraction mechanism is integrated with the lanyard lock base. In a more detailed embodiment, the lanyard cord retraction mechanism includes a feed hole for receiving slack lanyard cord; and the lanyard suspension system further includes (c) a lanyard cord feed-through component adapted to be coupled adjacent to the outlet hole and the feed hole, where the feed-through component includes: (i) an outlet channel extending from an interior side of the feed-through component to an exterior side of the feed-through component, (ii) an inlet channel extending from an exterior side of the feed-through component to an interior side of the feed-through component, and (iii) a tab extending from the exterior side of the feed-through component in between the inlet channel and the outlet channel, where the tab is adapted to seat a segment of the lanyard cord extending between the inlet channel and outlet channel thereon. With this design, a user may grip the segment of the lanyard cord seated on the tab.

It is a third aspect of the present invention to provide a lanyard suspension system for a prosthetic limb that includes: (a) a lanyard cord adapted to extend from a distal end of a patient's residual limb; and (b) a lanyard lock assembly adapted to be coupled to a prosthetic limb assembly. The lanyard lock assembly includes: (1) a lanyard lock base having a lanyard cord channel extending therethrough from an inlet hole of the lanyard lock base to an outlet hole of the lanyard lock base, where the lanyard cord channel is adapted to receive the lanyard cord extending therethrough; and (2) a locking mechanism designed to allow the lanyard cord to freely thread through the lanyard cord channel from the inlet hole to the outlet hole while substantially inhibiting the lanyard cord to thread in the opposite direction when in an active setting and designed to allow the lanyard cord to freely thread through the lanyard cord channel in both directions when in an inactive setting, where the locking mechanism utilizes at least one biased jaw for engaging with the lanyard cord in the cord channel when the lanyard cord is pulled in the opposite direction in the active setting. In a more detailed embodiment, the locking mechanism is biased to the active setting. In yet a further detailed embodiment, the lanyard lock assembly includes a manually actuated release button operatively coupled to the locking mechanism for allowing manual manipulation of the locking mechanism from the active setting to the inactive setting.

In an alternate detailed embodiment of the third aspect of the present invention, the lanyard suspension system further includes (c) a lanyard cord retraction assembly adapted to hold slack lanyard cord extending out through the outlet hole of the lanyard lock base. In a more detailed embodiment, the lanyard cord retraction assembly includes a spool for winding slack lanyard cord extending out through the outlet hole of the lanyard lock base thereabout.

It is a fourth aspect of the present invention to provide a method for donning a prosthetic limb assembly on a patient's residual limb that includes the steps of: (a) attaching a lanyard cord to a distal end of a patient's residual limb; (b) installing a lanyard lock assembly to a prosthetic limb assembly, the lanyard lock assembly including a lanyard lock base having a lanyard cord channel extending therethrough from an inlet hole of the lanyard lock base to an outlet hole of the lanyard lock base, where the lanyard cord channel is adapted to receive the lanyard cord extending therethrough; (c) threading the lanyard cord into the inlet hole and out through the outlet hole of the lanyard lock base; (d) manually pulling on the lanyard cord extending out through the outlet hole of the lanyard lock base to draw the patient's residual limb to the prosthetic limb assembly; and (e) winding any slack lanyard cord extending out through the outlet hole of the lanyard lock base on a spool positioned approximate to or integrated with the lanyard lock assembly. It is to be understood that the above steps need not proceed in the exact order presented. In a further detailed embodiment, the winding step is automatically performed by a winding mechanism operatively coupled to the spool.

DETAILED DESCRIPTION

As shown inFIG. 1, an exemplary prosthetic limb socket assembly includes a rigid outer socket20, typically constructed of a thermoplastic material, shaped for receiving a patient's residual limb21therein, where the outer socket component20includes a distal extended portion22for seating a lanyard lock component24therein in accordance with an exemplary embodiment of the present invention. A resilient inner socket26, typically formed from a silicone material, is donned on the patient's residual limb21and includes a lanyard cord28extending from an attachment tab30threaded to a distal end of the inner socket26. The lanyard cord28extends into a center hole30positioned within the concave proximal end32of the lanyard lock24and extends out through a radial side hole34of the lanyard lock24and on through a radial side hole36bored through the extended portion22of the outer socket component20.

Thus, the patient may grip the distal portion38of the lanyard cord extending out through the radial hole36and pull on the distal portion38of the lanyard cord such that the residual limb21is pulled distally towards the concave proximal end32of the lanyard lock24until the patient's residual limb covered by the inner socket26is comfortably and securely received within the outer socket20. The lanyard lock24of the exemplary embodiment is designed such that the cord28is freely threaded forwardly through the lanyard lock24as described above, but automatically locked from threading rearward back through the lock24, unless the release button40of the lanyard lock is engaged. Therefore, the user can incrementally tug his or her residual limb21into the outer socket20without worrying about the lanyard cord28pulling back out from the lanyard lock24as the outer socket20is being donned. This is very useful in circumstances where the residual limb has a difficult time being received within the outer socket20and the user needs to pull the residual limb into the outer socket to a certain extent by pulling on the distal portion of the lanyard cord38, walk around or adjust the residual limb a bit such that certain portions of the patient's limb settle within the socket20, and then pull again on the distal portion38of the lanyard cord to further draw in the distal end of the patient's residual limb. Such a donning process could be repeated until the residual limb is snugly and securely received within the outer socket20.

Of course, to remove the patient's residual limb, the patient merely activates the release button40, thereby unlocking the lanyard cord28within the lanyard lock24and then pulls his or her residual limb21out again from the outer socket20. At that point, the connection tab30can be unscrewed from the inner socket26to release the residual limb21from the lanyard system.

As shown inFIGS. 2-4, the exemplary lanyard lock24includes a substantially cylindrical base component42having a concave proximal surface32and including a center hole44provided at the center of the concave surface for receiving the lanyard cord28therein. As shown best inFIG. 3, the hole44opens distally on a cord channel46bored in the distal end of the base42where the cord channel46extends radially out and opens at the radial cord outlet opening34. This cord channel46includes a substantially round expanded portion48for seating a pivoting jaw50and its associated pivot pin52therein. The pivoting jaw50is also pivotally coupled to an elongated link bar54at an off-center point on the pivoting jaw50by a pin53. The link bar54can reciprocate in a radial channel56that extends below the cord channel46in a radial direction generally away from the opening34. A pin57couples the link bar54in parallel to an actuation post58of the release button40extending into a radial end of the base42opposing the cord opening34. A spring60is provided on the post58radially between a head62of the release button and an outer cylindrical wall64of the base42so as to bias the release button40radially outwardly from the base42. This bias, in turn, biases the link bar54in a radial direction towards the release button40(away from the cord outlet34), which in turn biases the jaw50to rotate clockwise such that the teeth66of the jaw grip and press the cord28extending through the cord channel46against a side wall of the cord channel46. The above-described locking mechanisms are covered by a cover65received flush within a recess67bored into the distal end of the base42and secured by screws69.

As can be shown inFIG. 4, if a user were to pull on the distal portion38of the cord, the cord would pull the teeth66in the jaw50counter-clockwise (because the teeth66are gripping into the cord28) and, in turn, release the teeth66from the cord28within the lock24so that the cord28may be freely threaded through the lock24. Conversely, if the user were to pull on the opposite end of the cord, such pulling would further pivot the jaw50clockwise, further locking the teeth66with the cord28against the side wall of the cord channel46.

As shown inFIG. 5, when the release button is pressed radially inwardly by the patient, the radially inward movement of the link bar54causes the jaw50to rotate counter-clockwise, thereby moving the teeth66out of the path of the cord28. This, in turn, allows the cord28to thread freely in either a forward or backward direction within the cord channel46.

In the exemplary embodiment, the design of the lanyard lock24allows it to have a low profile of ½″, weighing approximately 3.8 oz. Furthermore, the lanyard lock24design allows it to be accommodated by using conventional lock tools provided by Prosthetic Design Inc., such as SSFT, DLP-KIT, FET-KIT. Finally, the design of the lanyard lock24allows to be retrofit with Xtreme and Pro Locks commercially available from Prosthetic Design, Inc.

As shown inFIGS. 6 and 7, a first exemplary embodiment of an automatic cord retraction mechanism68for retaining the slack of the distal end38of the lanyard cord includes an attachment plate portion70for mounting to the distal end of outer socket's extended portion22, and a main body portion71housing the winding mechanisms for automatically retracting the slack distal end38of the lanyard cord when the user is no longer gripping it. The attachment plate portion70includes a standard 4-hole attachment pattern, where the holes are slotted to allow the mechanism68to be drawn against the circumference of the outer socket extended portion22. The body portion71of the mechanism68is also contoured to integrate with the outer socket extended portion22so as to help prevent accidental catch on other object.

The retraction mechanism68includes a cord spool72coaxially mounted to a spring reel74on a rotational hinge or axis76. The spring reel74contains a constant force spring78wound thereon, where one end of the constant force spring is attached to the hub of the reel74and the other end of the constant force spring is attached at an outer periphery of the reel74. The cord spool72contains slack portion of the cord38wound thereon, which feeds into and out from the winding housing71from an outer opening82. To provide the patient access to the lanyard cord38, the cord38feeds out from the opening82, over the body portion71, and into the cord hole36bored in the side of the extended portion22of the outer socket20. The winder operates such that when the patient pulls slack cord out from the winder housing68causing the cord spool72and spring reel74to rotate in a first direction, the spring78will build a centrifugal kinetic force such that when the cord is released again the kinetic force built into the spring78will cause the spool and reel72,74to spin in the opposite direction, thereby causing the slack cord to wind again around the cord spool72.

FIGS. 8 and 9illustrate an embodiment of a cord retraction mechanism built into a four-hole extender plate84mounted to a distal end of the prosthetic limb outer socket. The extender plate includes three sub-plates, a top plate86; a middle, cord spool plate88including a spool89for winding up the slack cord; and a lower, spring plate90including a constant force spring91coupled to the spool plate88by a pin87extending axially through the middle plate88and rotationally seated in the top and lower plates86,90. As will be recognized by one of ordinary skill in the art, the extender plate embodiment ofFIGS. 8 and 9, operates in a similar manner to the winder mechanism described above with respect toFIGS. 6 and 7.

FIG. 10illustrates a single plate embodiment92of the extender plate cord retraction mechanism described above withFIGS. 8 and 9. In this embodiment92, the cord spool94and spring reel96are both provided on the same plate and are coupled to each other for simultaneous rotation by a gear assembly98.

FIG. 11illustrates a cord retraction mechanism built into the lanyard lock embodiment described inFIG. 1-5above. In this embodiment, the base42includes a spring reel100and a cord spool102coaxially mounted therewithin about a hinge104, through which the cord hole44′ extends into the cord channel46′. Cord slack38is fed from the radial side opening34′, out through the adjacent outer socket wall, over a D-shaped gripping tab as described below, back into the outer socket wall, and back into the cord spool102through a radial side hole106.

FIGS. 12 and 13illustrate a gripping assembly for allowing user to grip the cord38threaded out from the side hole34′ and back into the feed hole106as shown inFIG. 11. A hole108is bored into the radial side of the extended portion22of the outer socket adjacent to the outlet hole34′ and inlet hole106. A feed-through component110which includes a diametric channel112extending therethrough is mounted in the hole108. A D-shaped tab component114is mounted over the channel112such that the D-shaped tab portion116of the component114leaves upper and lower openings118,120for a loop of the cord38to extend out through. When the excess cord is reeled into the cord retraction mechanism shown inFIG. 11, the D-shaped tab116retains a portion of the loop of cord38thereover allowing the user to easily grip the loop and pull on the cord.

It will be appreciated that with the above-described cord retraction mechanisms that the springs can be replaced with powered winders. It will also be appreciated that the force of the springs or the powered winders could be such that the need for the patient to pull on the distal section of cord38when donning the outer socket22is reduced or eliminated (i.e., sufficient pull could be provided by the retraction mechanisms themselves). In such embodiments, it might not be necessary to feed a portion of the distal cord38out from the socket for the patient to grip and pull on (i.e., the distal portion of cord38can be completely contained within the lock/winding mechanism).

Following from the above detailed description, it will be apparent to those of ordinary skill in the art that, while the apparatuses and processes herein described constitute exemplary embodiments of the present invention, it is understood that the invention is not limited to these precise apparatuses and processes and that changes may be made therein without departing from the scope of the invention as claimed or as illustrated by the various aspects of the present invention set forth in the summary. Additionally, it is to be understood that the invention is defined by the claims and it is not intended that any limitations or elements describing the exemplary embodiments set forth herein are to be incorporated into the meanings of the claims unless such limitations or elements are explicitly listed in the claims. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects of the invention disclosed herein in order to fall within the scope of any claims, since the invention is defined by the claims and since inherent and/or unforeseen advantages of the present invention may exist even though they may not have been explicitly discussed herein.