Patent Application
20160175134
Millions of patients worldwide suffer from hip, knee, and ankle joint disorders, including quadriceps weakness, Patellofemoral Pain Syndrome, or from injuries, stroke, post-polio, multiples sclerosis, or SCI. An improvement in lower extremity assistive devices will benefit some or all of these patients. However, with few exceptions, orthotic options for this population are limited to technologies that cannot provide assistance necessary to replicate the function of an unaffected limb. Accordingly, there is great potential for the development of orthosis devices to drastically increase the quality of life of this population. Gait pathologies and musculoskeletal disorders are often stabilized using a leg orthosis, typically consisting of a crude hard piece of material formed to the wearer's leg. Recently, new orthotic technologies have been introduced that employ external actuators and powered systems to rigidly lock the knee during the stance phase and unlock it during the swing phase of the gait. External actuators and powered systems are generally bulky and often result in low gait speed, joint pain due to additional load, and/or an unnatural gait. Powered systems require a power source, and are prone to faulty operation if the power system dies or malfunctions. Furthermore, powered orthotic devices require sensors and electronics, which have not shown the level of reliability and endurance that is required for medical applications. Thus, there is a need in the art for a small-size purely mechanical orthotic device that does not require an external power source, sensors and electronics.
The invention is a purely mechanical passive orthotic joint that utilizes a friction-based latch manipulated by a tri-state mechanism. The orthotic joint allows for impedance modulation in that the knee joint is compliantly supported during the weight acceptance phase and dampens downward forces for the user, and the knee joint is allowed free rotation during the swing phase. The present invention solves issues associated with powered and electronic orthoses, has a small size and light weight, it can be used bilaterally, is passive and mechanical and can be used in any environment of the daily life, and has high endurance and reliability. Moreover, the device according to aspects of the invention can be used for prosthetic applications as a knee-ankle-foot or knee-ankle prosthesis.
In one aspect, the present invention relates to a friction-based impedance module, comprising: an engagement fixture, a locking mechanism, a chassis, and a lower frame, wherein the chassis is connected to the lower frame by a pivoting joint, wherein the module is configured to lock the pivoting joint responsive to an increased torque load, and wherein the module is configured to unlock responsive to a decreased torque load.
In one embodiment, the locking mechanism is at least partially housed within the engagement fixture. In one embodiment, the locking mechanism comprises a plunger, a friction trail, and a friction lever with a trail slot. In one embodiment, the friction trail passes through the trail slot of the friction lever. In one embodiment, the alignment of the trail slot with respect to the friction trail is controlled by the engagement fixture. In one embodiment, the trail slot contacts the friction trail to lock the pivoting joint. In one embodiment, the friction trail has a protrusion or void at an angle that prompts the engagement fixture into an engaged configuration. In one embodiment, the friction lever is released from the engaged configuration by a magnet, a spring, a solenoid, gravity, a motor, or movement of a user's limbs. In one embodiment, the friction-based impedance module further comprises a mechanism for delaying the unlocking of the friction-based impedance module in response to a decreased torque load.
In one embodiment, the locking mechanism is selected from the group consisting of: a ratchet and pawl mechanism, a roller clutch mechanism, a hydraulic mechanism and a wrap spring clutch mechanism. In one embodiment, the friction-based impedance module further comprises at least one of a safety lock, configuration lock, dials, adjustment knobs, range of motion limits, dampers, and lubricating system. In one embodiment, the spring is replaced by a rubber band or other elastic material.
In another aspect, the present invention relates to a hip-knee-ankle-foot orthosis (HKAFO), hip-knee-orthosis (HKO), knee-ankle-foot orthosis (KAFO), ankle foot orthosis (AFO), hip orthosis (HO), shoulder orthosis (SO), elbow orthosis (EO), wrist orthosis (WO), or knee orthosis (KO) comprising the friction-based impedance module of the present invention.
In another aspect, the present invention relates to a serpentine spring device comprising a two-dimensional plate having at least one S-shaped region. In one embodiment, the serpentine spring is composed of at least one material selected from the group consisting of: carbon fiber, a metal, and a composite material. In one embodiment, the serpentine spring further comprises at least one additional stacked plate to modulate the flexibility of the device.
In another aspect, the present invention relates to an orthotic device, comprising: an impedance module including a chassis, a lower frame, and a walking member; wherein the chassis is coupled to the lower frame by a pivoting joint; and wherein the walking member is coupled to the lower frame by a serpentine spring.
In one embodiment, the spring comprises at least one of a carbon fiber, metal, or composite material. In one embodiment, the impedance module further comprises an engagement fixture and a locking mechanism, such that the module is configured to lock the pivoting joint responsive to an increased torque load, and wherein the module is configured to unlock responsive to a decreased torque load.
In one embodiment, the locking mechanism is at least partially housed within the engagement fixture. In one embodiment, the locking mechanism comprises a plunger, a friction trail, and a friction lever with a trail slot. In one embodiment, the friction trail passes through the trail slot of the friction lever. In one embodiment, the alignment of the trail slot with respect to the friction trail is controlled by the engagement fixture. In one embodiment, the trail slot contacts the friction trail to lock the pivoting joint. In one embodiment, the friction trail is released by a magnet, a spring, a solenoid, gravity, a motor, or movement of a user's limbs. In one embodiment, the locking mechanism is selected from the group consisting of: a ratchet and pawl mechanism, a roller clutch mechanism, a hydraulic mechanism and a wrap spring clutch mechanism.
The following detailed description of preferred embodiments of the invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments, which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities of the embodiments shown in the drawings.
It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for the purpose of clarity, many other elements found in typical orthosis devices. Those of ordinary skill in the art may recognize that other elements and/or steps are desirable and/or required in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein. The disclosure herein is directed to all such variations and modifications to such elements and methods known to those skilled in the art.
Unless defined elsewhere, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described.
As used herein, each of the following terms has the meaning associated with it in this section.
The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.
“About” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20%, ±10%, ±5%, ±1%, and ±0.1% from the specified value, as such variations are appropriate.
Throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, 6, and any whole and partial increments therebetween. This applies regardless of the breadth of the range.
The present invention includes a mechanical friction-based impedance modulation device (weight acceptance control orthosis) for orthotic applications. The device can function in parallel with any upper or lower extremity joints, such as the elbow or knee joint for example, to replace or supplement the function of an impaired joint. The device locks in response to a torque, such as a torque caused by rotation or a user's weight load on a joint, and subsequently unlocks upon removal of the torque to restore full range of motion to the joint. The device is capable of locking at any angle in response to a torque.
Referring now to
Referring now to
Referring now to
As illustrated, side frames 1 and 3, and rear frame 2 are connected to each other via pin 38 engaging holes 36, such that engagement fixture 14 moves as a single unit. In such an embodiment, at least one rubber band 24 loops around anterior rod 42 and rubber band anchor 52. The position of rubber band anchor 52 may be adjustable by inserting it in any one of adjustment points 66 of chassis 12. Accordingly, adjusting the position of rubber band anchor 52 also adjusts the force that the at least one rubber band 24 exerts upon anterior rod 42.
Leaf spring 28 is attached to the distal end of friction lever 26, such that leaf spring 28 and friction lever 26 move as a single unit. Accordingly, pin 38 resists the range of movement by leaf spring 28 when pin 38 is engaged with holes 36. Further, friction lever 26 is positioned to engage with chassis 12 such that it fits into friction lever guide 74 of slot 60. Thus, the proximal edge of friction lever 26 rests against posterior rod 40 and anterior rod 42. The selected magnet slot 62 holds or otherwise engages magnet 16. Accordingly, the position of magnet 16 is also adjustable by inserting it in any of magnet slots 62. Once in position, magnet 16 magnetically attracts friction lever 26.
As shown, friction trail 30 is attached to the extended arms of lower frame 54, thereby allowing friction trail 30 and frame 54 to move as a single unit. In this configuration, friction trail 30 passes through trail slot 53 of friction lever 26. Accordingly, engagement fixture 14, chassis 12, and lower frame 54 may be joined together at joint 34. As shown, engagement fixture 14, chassis 12, and lower frame 54 pivot independently about joint 34. For example, lower frame 54 may pivot in flexion to move friction trail 30 in an anterior direction, or lower frame 54 may pivot in extension to move friction trail 30 in a posterior direction. As such, stopper rod 56 limits the range of pivot by lower frame 54.
Friction trail 30 provides the friction for locking exemplary friction-based impedance module 10 depicted in
As shown in
In one embodiment, plunger 22 is housed within tunnel 70 of chassis 12, and the posterior end of plunger 22 rests against rear frame component 2. Further, a spring wraps around the proximal edge of rear frame 2 and is anchored to chassis 12 by spring attachment 68. Accordingly, the spring anchored by spring attachment 68 maintains the contact between rear frame 2 and the posterior end of plunger 22. In one embodiment, the anterior end of tunnel 70 is plugged by a threaded screw. In one embodiment, plunger spring 50 is compressed within tunnel 70 between plunger 22 and a threaded screw.
Posterior rod 40 and anterior rod 42 fit into plunger rod guides 72 of slot 60. In one embodiment, plunger rod guides 72 are dimensioned such that they permit posterior rod 40 and anterior rod 42 to move in only the proximal and distal directions. In this configuration, posterior rod 40 holds the position of plunger 22. For instance, posterior rod 40 may rest in short notch 44 against posterior ridge 47 to maintain plunger 22 in an anterior position. In another instance, posterior rod 40 may rest in long notch 46 against anterior ridge 48 to maintain plunger 22 in a posterior position. Alternatively, anterior rod 42 holds the position of plunger 22. For instance, anterior rod 42 may rest in long notch 46 against anterior ridge 48 to maintain plunger 22 in a medial position.
Friction-based impedance module 10 is amenable for use in any application wherein the function of a joint, such as an impaired joint, is in need of having its function replaced or supplemented. In particular, friction-based impedance module 10 can be used in an orthosis to replace or supplement the function of a joint. Friction-based impedance module 10 can also be used to replicate the function of a joint in a prosthetic. Suitable joints include those of the lower extremities and the higher extremities, such as the hip, the knee, the ankle, the wrist, the elbow, the shoulder, and the like. Accordingly, any embodiment of friction-based impedance module 10, any embodiment of serpentine spring 18, either separately or in combination, may be incorporated into any type of orthosis device. Example orthoses include hip-knee-ankle-foot orthoses (HKAFO), hip-knee-orthoses (HKO), hip-knee-ankle orthoses (HKAO), knee-ankle-foot orthoses (KAFO), knee-ankle orthoses (KAO), ankle-foot orthoses (AFO), knee orthoses (KO), hip orthoses (HO), shoulder orthoses (SO), elbow orthoses (EO), wrist orthoses (WO), and the like.
It should be understood that the devices of the present invention may comprise any additional elements that enhance the function or safety of the devices. For example, the additional elements may improve device performance, customization, and ease of use. Non-limiting examples of such elements include safety locks, configuration locks, dials, adjustment knobs, range of motion limits, dampers, lubricating systems, and the like.
Accordingly, friction lever 26 does not impede the movement of friction trail 30 in this configuration. For instance, friction trail 30 is free to move in an anterior direction, such as when lower frame 54 pivots in flexion, and friction trail 30 is free to move in a posterior direction, such as when lower frame 54 pivots in extension. Now with reference to
In a second state that starts in the swing phase when the knee maximally flexes and ends at the beginning of the stance phase when the knee starts flexing, friction-based impedance module 10 is primed and is ready to lock in response to a torque, such as from a rotation or weight load. At the start of this second state, and still with reference to
In this second state, the angled position of trail slot 53 allows friction trail 30 to move unimpeded in a posterior direction, such as when lower frame 54 pivots in extension. Now with reference to
In a third state that starts at the beginning of the stance phase and ends at the end of the weight acceptance phase around ˜40% through the gait cycle when the device is unloaded, friction-based impedance module 10 has locked in response to a weight load. As shown in
In this third state, as long as the wearer's weight remains upon friction-based impedance module 10 and maintains the torque, flexion by lower frame 54 will be locked. Removing the weight load removes the torque and shifts friction-based impedance module 10 back into the first configuration. Without the torque provided by the weight load, anterior rod 42 is pulled distally by the at least one rubber band 24. Posterior rod 40 is now pushed proximally by the proximal edge of friction lever 26. Plunger 22, having been released by the distal motion of anterior rod 42, is now pushed posteriorly by plunger spring 50. Plunger 22 stops posterior movement once posterior rod 40 seats in long notch 46 and rests against anterior ridge 48. Friction-based impedance module 10 has returned to the first configuration.
In some embodiments, the friction-based impedance module of the present invention further comprises a delay mechanism for delayed unlocking. For example, the mechanism may delay the friction-based impedance module from shifting from the third configuration to the first configuration upon the decrease or removal of a torque, such that friction-based impedance module remains locked for a brief period of time. A delay mechanism may be advantageous to enhance a user's ability to recover from a stumble in a lower extremity orthosis, or for tremor suppression in an upper extremity orthosis. In a moment of imbalance or weakness, the torque on a locked friction-based impedance module may be inadvertently removed. A delay mechanism allows the device to be able to provide a user with a brief period of time where the friction-based impedance module stays locked, giving the user the structural support needed to regain balance or suppress tremor.
In certain embodiments, the delay mechanism allows a limited range of motion in the friction-based impedance module upon the decrease or removal of a torque. For example, it may be advantageous for a user to have a functional range of motion for stumble recovery. The delay mechanism may restrict the friction-based impedance module to a safe range of motion for a brief period of time following the decrease or removal of a torque.
The disclosures of each and every patent, patent application, and publication cited herein are hereby incorporated herein by reference in their entirety.
While this invention has been disclosed with reference to specific embodiments, it is apparent that other embodiments and variations of this invention may be devised by others skilled in the art without departing from the true spirit and scope of the invention. The appended claims are intended to be construed to include all such embodiments and equivalent variations.
This application claims priority to U.S. Provisional Patent Application No. 62/094,456 filed Dec. 19, 2014, the contents of which are incorporated by reference herein in their entirety.
This invention was made with government support under grant No. W81XWH-11-2-0054 awarded by the United States Defense Medical Research Development Program. The Government has certain rights in the invention.
| Number | Date | Country | |
|---|---|---|---|
| 62094456 | Dec 2014 | US |
