4. DESCRIPTION
TECHNICAL FIELD
[001] The present disclosure generally relates to wearable type exoskeleton devices. More particularly, the present disclosure relates to a self-adjustingfoot assistant apparatus for providing a more stable support for wearers of lower extremity orthoses and exoskeleton devices.
BACKGROUND
[002] In general, lower limb orthoses and lower extremity exoskeletons share similar structure and are worn by users. Lower limb orthoses such as ankle-foot orthosis (AFO), knee-ankle-foot orthosis (KAFO), hip-knee-ankle-foot orthosis (HKAFO), and variants of these are used by people with leg disabilities or weak muscles so as to assist or enable them in walking or standing. While some users of these orthoses can balance without additional supporting aids obtained through canes, crutches, or walkers, others need these supporting aids in addition to using the orthoses so as to avoid losing balance and falling. These supporting aids engage the hands of the wearer and essentially increase the support area on the ground. Lower extremity exoskeletons such as (ExoHikerTM, ExoClimberTM, and HULC, for e.g.) are used by normal people to augment their load carrying abilities on their back. Both lower limb orthoses and lower extremity exoskeletons benefit by having a larger foot support area. In the case of lower limb orthoses, the reliance on canes, crutches or walkers can be reduced if a larger foot support area is provided by the foot and utilized in the design of the orthoses.
[003] Exoskeleton devices carrying heavy loads do not usually have their center of masses aligned with that of wearers. The wearer of the exoskeleton feels the least strain when the wearer is able to walk with one’s normal gait. When heavy loads are being carried on the exoskeleton devices, if normal foot support (same as the wearer’s shoes) is used, the wearer has to change his gait so that the zero

moment point lies within the normal foot support. Zero Moment Point, popularly called as ZMP, is a point on the ground surface whose location indicates absolute stability (stable or unstable) or relative stability (how far the system is away from stability). Instability in the case of human gait refers to falling. As long as this point is within the foot support region (region of the foot in contact with the ground surface), the system (human or human wearing lower limb orthosis or human wearing lower extremity exoskeleton) is stable. Enlarging the lateral foot support area increases the relative stability if this area is properly considered while designing the orthosis or exoskeleton, in which case, the wearer can feel the supporting forces on the sides of the orthosis or exoskeleton.
[004] In the light of the aforementioned discussion, there exists a need for foot device with larger support area that can increase the stability of the wearer of lower limb orthoses or lower extremity exoskeletons. Such a foot device, while providing larger support area, should not interfere with normal walking or standing by yielding or self-adjusting to obstacles that may be encountered.
BRIEF SUMMARY
[005] The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.
[006] An objective of the present disclosure is directed towards providing an extended foot support, the wearer can walk normally and the zero moment point can actually go outside of normal support area to the extended support area.

[007] Another objective of the present disclosure is directed towards adjusting the position of the lateral arms to maintain proper contact with the ground when the user is standing still with both legs together.
[008] Another objective of the present disclosure is directed towards extending lateral stability (in frontal plane) of the user.
[009] Another objective of the present disclosure is directed towards reducing the reliance on external supporting aids such as cranes, crutches, walkers, or frames.
[0010] Exemplary embodiments of the present disclosure are directed towards a self-adjusting foot assistant apparatus.
[0011] In an exemplary embodiment of the present disclosure, the self-adjusting foot assistant apparatus comprising a first foot plate and a second foot plate.
[0012] In another exemplary embodiment of the present disclosure, the self-adjusting foot assistant apparatus comprising first lateral arms attached to the first foot plate and second lateral arms attached to the second foot plate.
[0013] In another exemplary embodiment of the present disclosure, the self-adjusting foot assistant apparatus comprising the first lateral arms or the second lateral arms pointed sideways with respect to the first foot plate or the second foot plate and inwards.
[0014] In another exemplary embodiment of the present disclosure, the self-adjusting foot assistant apparatus further comprising the first lateral arms of the first foot plate positioned on top of second lateral arms of the second foot plate when a user is standing still with both legs together, thereby the position of the second lateral arms adjust themselves with respect to the position of the first

lateral arms to maintain proper contact with a ground or vice-versa depending on which foot plate is already on the ground. [0015] In another exemplary embodiment of the present disclosure, the self-adjusting foot assistant apparatus further comprising at least one top plate of the first foot plate and at least one bottom plate of the first foot plate sandwiched to hold a plurality of guideways and at least one slider that can slide along the plurality of guideways.
BRIEF DESCRIPTION OF DRAWINGS
[0016] Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, in conjunction with the accompanying drawings, wherein like reference numerals have been used to designate like elements, and wherein:
[0017] Figure 1 is a diagram that depicts an embodiment of a self-adjusting foot assistant apparatus, in accordance with one or more exemplary embodiments of the present disclosure.
[0018] Figure 2A-FIG. 2B are diagrams depicting an internal representation of a foot plate and the lateral arm, in accordance with one or more exemplary embodiments of the present disclosure.
[0019] Figure 3is a diagram depicts another embodiment of a self-adjusting foot assistant apparatus, in accordance with one or more exemplary embodiments of the present disclosure.
[0020] FIG. 4 is an example diagram depicting the user in different planes, in accordance with one or more exemplary embodiments.

DETAILED DESCRIPTION
[0021] It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[0022] The use of “including”, “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. Further, the use of terms “first”, “second”, and “third”, and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.
[0023] Referring to Figure 1 is a diagram 100 depicts an embodiment of a self-adjusting foot assistant apparatus, in accordance with one or more exemplary embodiments of the present disclosure. The self-adjusting foot assistant apparatus 100 comprising a first foot plate 102, a second foot plate104 whose support area is higher than normal foot support area. The first foot plate and the second foot plate 102-104 may include but are not limited to, a right foot plate, a left foot plate, and the like. Each of these first and second foot plates 102, 104 has first lateral arms, second lateral arms 106a-106b, 108a-108b which are pointed sideways with respect to the foot and inwards. The first lateral arms 106a-106b of the first foot plate 102 may be positioned on top of second lateral arms 108a-108b of the second foot plate 104 when a user is standing with both legs together, thereby the position of the first lateral arms 106a-106b and the second lateral arms 108a-108b adjust themselves to maintain proper contact with a ground.

[0024] Each of first and second lateral arms 106a, 106b, 108a, and 108b on the foot plate 102 or 104 may fold to a position such that it is in line with the foot, in which configuration they may be locked using a snap fit locking mechanism (not shown), or extend fully perpendicular to the foot or at an angle to the perpendicular. The natural position of each of lateral arms 106a, 106b, 108a, and 108b may be an extended position which is achieved by means of a torsion spring (not shown). Each of lateral arms 106a, 106b, 108a, and 108b may be held on a slide through a pin joint to which the torsion spring (not shown) is attached. The length of the lateral arms 106a, 106b, 108a, and 108b may also be adjusted to suit the wearer’s needs.
[0025] Referring to Figure 2A-FIG. 2Bare diagrams 200a-200b depict an internal representation of a foot plate 102 or 104 and the lateral arm 106a or 108a, 106b or 108b, in accordance with one or more exemplary embodiments of the present disclosure. Each of the first and second foot plates 102 or 104 comprises of a top plate 112a and a bottom plate112b sandwiched to hold guideways 202a-202b and slide along with longitudinal springs 204. The slide carrying the lateral arms 106a or 106b, 108a or 108b is capable of moving longitudinally along the foot in a slot or on the guideways 202a-202b. The position of the slide may be maintained with respect to the foot on the guideways 202a-202b at a particular position by means of a linear spring206.
[0026] The slide may hold the lateral arm 106a or 106b, 108a or 108b which is attached to the slide through a revolute or pin joint along with the torsion spring 208. The lateral arms 106a or 106b, 108a or 108b may be telescopic with the linear springs 206 inside and also capable of rolling freely about their axis as depicted in FIG. 2B.If the tip of the lateral arm 106a or 106b, 108a or 108b may be pressed due to some obstacle, the lateral arm’s 106a or 106b, 108a or 108b effective length reduces due to spring compression. During the course of swing motion of the swing foot (foot which is not in contact with the ground), if the lateral arm 106a or 106b or 108a or 108b may be obstructed by an obstacle or the

supporting leg (which is in contact with the ground), the lateral arm 106a or 106b or 108a or 108b yields to the obstacle with the respective slide moving forward or backwards against the longitudinal spring force on the guideways or folds appropriately against the torsional spring torque and returns to its initial extended position once the obstacle is crossed.
[0027] Referring to Figure 3 is a diagram 300 depicts another embodiment of a self-adjusting foot assistant apparatus, in accordance with one or more exemplary embodiments of the present disclosure. The self-adjusting foot assistant apparatus 300includes first and second foot plates 102-104 which are aligned in a particular position. Due to the presence of spring-loaded slides, the position of the lateral arms 106a-106b or 108a or 108b may adjust themselves so that there is a proper contact with the ground. In an example, the lateral arms 106a-106b or 108a-108b of whichever foot plate foot plate 102 or 104 may not be adjusted as they are carrying the load. The lateral arms 106a-106b or 108a-108b of whichever foot plate 102 or 104 comes later on top of the lateral arms 106a-106b or 108a-108b of the other foot plate 102 or 104, only those may adjust and then come in contact with the ground. The self-adjusting foot assistant apparatus 300 comprises of first and second lateral arms 106a-106b and 108a-108b for each first and second foot plate102-104 on its inner side. The self-adjusting foot assistant apparatus 300 may be extended by also having the first and second lateral arms 106a-106b or 108a or 108b on the outer side of each foot plate 102-104 to provide further additional support area.
[0028] Referring to FIG. 4 is an example diagram 400 depicting the user in different planes, in accordance with one or more exemplary embodiments. The example diagram 400 depicting the user 402 in a sagittal plane 404, a transverse plane 406, and a lateral (frontal or coronal) plane 408. The self-adjusting foot assistant apparatus deals with the stability in the lateral (frontal or coronal) plane 408. The self-adjusting foot assistant apparatus extends the stability of generally

used orthoses or load carrying exoskeleton devices in the lateral (frontal or coronal) plane 408.
[0029] Although the present disclosure has been described in terms of certain preferred embodiments and illustrations thereof, other embodiments and modifications to preferred embodiments may be possible that are within the principles and spirit of the invention. The above descriptions and figures are therefore to be regarded as illustrative and not restrictive.
[0030] Thus the scope of the present disclosure is defined by the appended claims and includes both combinations and sub-combinations of the various features described hereinabove as well as variations and modifications thereof, which would occur to persons skilled in the art upon reading the foregoing description.

1. A self-adjusting foot assistant apparatus, comprising:
a first foot plate 102 and a second foot plate 104;
first lateral arms 106a-106b attached to the first foot plate 102 and second lateral arms 108a-108b attached to the second foot plate 104, the first lateral arms 106a-106b or the second lateral arms 108a-108b pointed sideways with respect to the first foot plate 102 or the second foot plate 104 and inwards or outwards or both ways; and
at least one top plate 112a of the first foot plate 102 or 104 and at least one bottom plate 112b of the first foot plate 102 or 104 sandwiched to hold a plurality of guideways 202a-202b.
2. The self-adjusting foot assistant apparatus as claimed in 1, wherein the first lateral arms 106a-106band the second lateral arms 108a-108b are an extended position which is achieved by means of torsion springs 208.
3. The self-adjusting foot assistant apparatus as claimed in 1, wherein the slide carrying the first lateral arms 106or the second lateral arms 108 capable of moving longitudinally along the foot in a slot or on the plurality of guideways 202a-202b.
4. The self-adjusting foot assistant apparatus as claimed in 1, wherein the position of the slide is maintained with respect to the foot on the plurality of guideways 202a-202b at a particular position by means of a plurality of linear springs 206.

5. The self-adjusting foot assistant apparatus as claimed in 1, wherein the first lateral arms 106a-106b and the second lateral arms 108a-108b are telescopic with the plurality of linear springs 206 inside.
6. The self-adjusting foot assistant apparatus as claimed in 1, wherein the first lateral arms 106a-106b and the second lateral arms 108a-108b are attached to the slides through pin joints along with the torsion springs 208.
7. The self-adjusting foot assistant apparatus as claimed in 1, wherein the telescopic portion of the first lateral arms 106a-106b and the second lateral arms 108a-108b can roll freely.
8. The self-adjusting foot assistant apparatus as claimed in 1, whereinthe first lateral arms 106a-106b and the second lateral arms 108a-108byield to an obstacle by movement of the respective slide on the guideways or fold appropriately about their pin joints or reduce length telescopically,and return to theirinitial extended position once the obstacle is crossed.
9. The self-adjusting foot assistant apparatus as claimed in 1, wherein the lateral arms 106 and 108 in fully folded configuration where the arms are in-line with the foot can be held in that configuration through a snap fit locking mechanism or any other locking mechanism so as to use the foot without extended lateral support area.