Provided is a wearable assisted-walking device including one lower attachment body to the foot defining a lower anchoring point at the heel of the foot of a leg of the user; an upper attachment body to an upper part of the leg proximal from the knee defining an upper ventral anchoring point and an upper dorsal anchoring point arranged on the opposite side of the coronal plane of the user; and an intermediate attachment body defining a first intermediate anchoring point, a second intermediate anchoring point and a third intermediate anchoring point, each anchoring point movable respect and connected by cables to the leg; the intermediate attachment body being adapted to store the energy by a relative motion between the anchoring points and then use it for assist walking.

The present invention relates to a wearable assisted-walking device of the type specified in the preamble of the first claim.

In particular, the invention relates to a solution for reducing the metabolic cost of human walking, and thus is usable to help a person during locomotion.

It is known that walking is realized by a periodic sequence of muscle activations that generate force positive and negative work/energy/power.

The muscles mainly used for walking are: the iliopsoas (IP), the gluteus maximus (GM), the biceps femoris (BF), the rectus femoris (RF), the vasti (in particular the vastus lateralis VL), the tibialis anterior (AT), the gastrocnemius (in particular the gastrocnemius medialis (MG), the soleus (Sol). Such muscles add to other muscles performing a negligible activity.

During a walking stride these muscles are active, and contribute to the mechanical energy that is absorbed and generated. In conclusion, the muscles of the leg provide positive and negative peak power while walking.

The most relevant and identifiable peak joint powers are: A1: negative power region that corresponds to the eccentric activity of the plantar flexor muscles that surround the ankle from heel-strike through tibial progression; A2: positive power region corresponding to the concentric contraction of the platarflexors during the late stance phase; K1: negative power region, corresponding to the eccentric contraction of the knee extensors during heel-strike; K2: positive power region, corresponding to the concentric knee extensor contraction during mid-stance; K3: negative power region, corresponding to the eccentric contraction in the rectus femoris during late stance; K4: negative power region, corresponding to the eccentric contraction in the biceps femoris during late stance; H1: positive power region, that is not always present, which corresponds to the concentric contraction of the hip flexors during the first half of the stance phase; H2: negative power region, corresponding to the eccentric contraction of the hip flexors during mid-stance; and H3: positive power region, corresponding to the concentric contraction of the hip flexors during pre-swing and initial leg swing.

Given this premise, the currently known wearable assisted-walking devices are identified by the acronym AFO (“Ankle Foot Orthosis”).

Such devices usually consist of a shell that is constrained at the ankle or leg, an attachment to the foot and/or the body, joints that allow movement between the shell and attachment, and one or more motorized actuators that simulate the muscles and control the motion between the shell and attachment. The described prior AFOs have some major drawbacks.

Additional drawbacks are the complexity, high costs, and high synchronization required between the device and the user during walking. In order to combat such drawbacks, previous investigators have developed passive wearable assisted-walking devices that do not include a motor. An example of such a wearable assisted-walking device is described in US2013046218 introducing a device taking advantage of the energy produced by the muscles.

In US2013046218 there is a shell attached to the leg and an attachment to the foot that allows a rotational joint, which is comprised of a linear actuator adapted to contract at peak A1. This device also includes spring that is attached to the shell, adapted to store the energy produced by the contraction of the linear actuator in A1, and allowed to control the extension of the linear actuator during pre-swing. Another device is KR20120044683A, which describes a wearable assisted-walking device that takes advantage of a kinematic mechanism similar to that of US2013046218. This device also has some major drawbacks.

One major drawback of this device is that it stores a very small amount of energy and thus is not usable for walking. Therefore, the device makes a limited contribution to assisting walking. The technical task underlying the present invention is to design a wearable assisted-walking device capable of substantially obviating the aforementioned drawbacks.

In the scope of this technical task, it is important that the present invention of a wearable assisted-walking device is passive and capable of taking advantage of the energy produced by the muscles when walking.

It is also important that the wearable assisted walking device does not change the motion of or overload the ankle or other joints.

It is a further objective of the invention to provide a wearable assisted-walking device that is simple, low-cost and easy to use.

In this situation, the technical task underlying the present invention is to devise a wearable assisted-walking device capable of substantially obviating the mentioned drawbacks at least in part.

In the scope of said technical task, it is an important object of the present invention to obtain a wearable assisted-walking device which is motor-free and thus capable of working by maximally taking advantage only of the energy produced by the muscles when walking.

It is another important object of the invention to provide a wearable assisted-walking device which does not excessively overload the ankle or other joint.

It is a further major object of the invention to provide a wearable assisted-walking device which is simple, low-cost and easy to use.

The technical task and the objects specified are achieved by a wearable assisted-walking device as claimed in appended claim1. Exemplary preferred embodiments are described in the dependent claims.

In the present invention, the measurements, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with words such as “about” or other similar words, such as “almost” or “substantially”, are to be understood as short of errors of measurement or inaccuracies due to production and/or manufacturing errors, and especially short of a minor divergence from the value, measurement, shape or geometric reference with which it is associated. For example, such words, if associated with a value, preferably indicate a divergence not higher than 10% of the value itself.

Furthermore, when used, words such as “first”, “second”, “upper”, “lower”, “main” and “secondary” do not necessarily identify an order, a relationship priority or a relative position but may be simply used to distinguish different components more clearly.

Unless otherwise indicated, the measurements and data shown in the test were performed in International Standard Atmosphere ISA (ISO 2533).

With reference to the Figures, the wearable assisted-walking device according to the invention is indicated by reference numeral1as a whole.

It is used to assist walking by acquiring energy during a first motion (in detail prior to and during heel-strike) and returning it during a second motion (in detail during a late stance), preferably not contiguous to the first movement. In particular, the wearable assisted-walking device1is adapted to store the energy produced during the extension of the knee and to release the energy in order to provide push-off at the ankle. Specifically, device1is adapted to store the energy produced at peak K4and to release the energy at the subsequent peak A2.

The wearable device1is adapted to be worn by a user, such as a person.

The wearable device1may comprise at least one lower attachment body2to a foot of the user. It preferably comprises two lower bodies2that are each adapted to be attached to each foot of the user.

Each lower body2defines a lower anchoring point2aat the heel of each foot.

In this document, the term “anchoring point” identifies a constraining point of a cable (described below) which prevents it from sliding (with respect to the anchoring point, and thus to the body to which it is constrained). The anchoring point may allow a rotation of the cable or alternatively define an integral constraint for the cable.

The lower body2may be a known as the lower attachment body to the foot. An example of such a lower body2is the “lower portion108” described and shown in US 20130046218.

The wearable device1may comprise at least one upper body3, preferably only one, suitable to be attached in an integral manner to an upper part of the leg of the user, i.e. proximal from the knee.

The “upper part of the leg” defines in this document the part of leg above the knee. The upper body3may be constrained to the torso, in particular to the abdomen, and specifically at the waist of the user. In this case, device1may comprise an additional upper body4(identifiable in one band) adapted to be attached to the user's thigh and defining one or more sliding slots for one or more cables described below for each lower body2.

The upper body3defines an upper ventral anchoring point3a(namely a frontal anchoring point), and an upper dorsal anchoring point3b(namely a rear anchoring point) for each lower body2.

In detail the upper attachment body3is suitable to be attached to the dorsal part of the back, above the gluteal muscles, defining for each of the attachment below the knee (see the intermediate body5below described), an upper ventral anchoring point3aarranged on the opposite site of the coronal plane of the user.

In use, i.e. when device1is worn by the wearer, the upper ventral anchoring point3aand the upper dorsal anchoring point3bare on opposite sides of the user's coronal plane.

The upper body3may comprise a belt.

The wearable device1may comprise an intermediate attachment body5to the user's leg.

Preferably the intermediate attachment body5is suitable to be attached to the user below the knee, i.e. to the shank or the lower limb portion between knee and foot.

The wearable device1may comprise an intermediate attachment body5for each lower body2.

Preferably, the intermediate body5is adapted to be constrained at the gastrocnemius muscle.

The intermediate body5(FIG. 2-3) may comprise an attachment51adapted to be attached, preferably integrally, to the leg, e.g. by a band.

The attachment51is adapted to be attached, preferably integrally, to the lower part of the leg and preferably to the shank. We highlight “lower part of the leg” defines in this document the part of leg below the knee.

The intermediate body5may comprise a kinematic storage mechanism52adapted to store energy and defining a first intermediate anchoring point5awhich is movable with respect to the attachment51and a second intermediate anchoring point5balso movable with respect to the attachment51.

In use, the first intermediate anchoring point5aand the second intermediate anchoring point5bare at the leg, and more precisely near the gastrocnemius muscle.

In detail in use, the intermediate anchoring points5aand5bare attached on opposite sides with respect to the user's coronal plane. Preferably, the first intermediate anchoring point5ais dorsal (namely frontal), while the second intermediate anchoring point5bis ventral (namely rear with respect to said coronal plane).

The kinematic storage mechanism52connects the first intermediate anchoring point5aand the second intermediate anchoring point5bin order to store the energy by taking advantage of a motion of the first intermediate anchoring point5awith respect to the attachment51and to release that energy by causing the movement of the second intermediate anchoring point5bwith respect to the attachment51.

The kinematic storage mechanism52stores energy by means of a movement thereof according to a loading direction and releases energy by means of a movement thereof according to a releasing direction opposite to the loading direction.

The kinematic storage mechanism52may define a rotation axis52aso as to have, for example, the loading and releasing directions which are counterclockwise and clockwise, respectively.

In use, the rotation axis52ais substantially parallel to the coronal plane, and more precisely substantially perpendicular to the user's sagittal plane.

The kinematic storage mechanism52comprises a pin521that defines the rotation axis52a; a stator522that does not rotate about the rotation axis52a; a rotor523that is adapted to rotate about the rotation axis52awith respect to the stator523; and at least one storage unit524interposed between stator522and rotor523that takes advantage of the reciprocal rotation in order to store and/or release energy.

In particular, the kinematic storage mechanism52may comprise multiple storage units524, preferably three, angularly and equally spaced apart with respect to the rotation axis52a.

The storage unit524is adapted to store energy by deforming elastically. It is a spring adapted to store energy, preferably by varying its length. More specifically, the storage unit524is a compression spring.

The stator522is integral with the attachment51.

For each storage unit524, stator522defines a resting surface522afor the storage unit524against which said unit524is compressed when storing energy.

Rotor523is adapted to rotate idly about the rotation axis52a, e.g. by virtue of bearings/bronze bearings interposed between rotor523and pin521.

For each storage unit524, rotor523comprises an arm523aadapted to enclose the storage unit524between the arm523aitself and a resting surface522athat causes either storage or release of energy by means of its rotation.

Rotor523preferably comprises multiple arms523a, three in detail, equally and angularly spaced apart.

The intermediate anchoring points5aand5bare associated with the rotor523, so that rotor523controls the storage of energy when it is pulled by the first point5a, and rotor523controls the displacement of the second intermediate anchoring point5bwhen it is pulled by the storage unit524.

The first intermediate anchoring point5aand the second intermediate anchoring point5bare constrained (either directly or indirectly) to rotor523conveniently at discrete arms523a.

In particular, the first intermediate anchoring point5ais integral with an arm523a. Alternatively, the kinematic storage mechanism52comprises a feeding block525with which the first intermediate anchoring point5ais integral and adapted to rotate about the rotation axis52athus feeding the rotor523at least when it is moved in the loading direction.

The feeding block525comprises one or more additional arms525a, one of which being integral with the first intermediate anchoring point5a; and a connector525bintegral with an additional arm525aand adapted to contact an arm523thus allowing the feeding block525to feed rotor523when it is moved in the loading direction.

It is worth noting that the rotor523, when moved in the releasing direction, feeds the feeding block525.

Preferably, the feeding block525and the rotor523are spaced apart along the rotation axis52aand enclose said stator522.

The second intermediate anchoring point5bis integral with an arm523a, discrete from that with which the first intermediate anchoring point5ais associated.

In order to ensure the release of energy only at the desired time, the intermediate body5may comprise a locking system53of the kinematic storage mechanism52adapted to selectively prevent or permit the energy release.

The locking system53defines a third intermediate anchoring point5cat attachment51, movable with respect to attachment51.

In use, the third intermediate anchoring point5cis on the same side as the first point5awith respect to the coronal plane.

The third intermediate anchoring point5cis on the side opposite to the second intermediate anchoring point5bwith respect to the first intermediate anchoring point5a.

As a function of the position of the third intermediate anchoring point5cwith respect to attachment51, the locking system53defines a locking portion, where the motion of the kinematic storage mechanism52is prevented in the releasing direction, and a releasing position, where the motion of the kinematic storage mechanism52is allowed in the releasing direction and thus allows the release of the energy.

The locking system53does not interfere with the kinematic storage mechanism52which allows the motion in the loading direction in both locking position and releasing position.

In brief, in locking position, the locking system53prevents the motion of rotor523in the releasing direction and preferably allows the motion of rotor523in the loading direction; while in the releasing position, it allows the motion of rotor523in the loading and releasing directions.

The locking system53can be identified as a known ratchet and pawl that can be controlled by the third anchoring point5c. It comprises a toothed wheel531adapted to rotate about the rotation axis52aand integral with rotor523; at least one tooth532adapted to engage the toothed wheel532defining the locking portion and/or to be disengaged from the toothed wheel532defining the releasing position.

In some cases, the locking system53may comprise thrust means, such as a preloading spring, adapted to override the engagement of tooth532with the toothed wheel531.

Tooth532is hinged to stator522in order to rotate about an axis preferably substantially parallel to the rotation axis52a.

The third intermediate anchoring point5cis constrained and, in detail, integral with the tooth532, in order to control the switch to the releasing position.

The intermediate body5may comprise a loading cable54connecting the upper dorsal anchoring point3bto the first intermediate anchoring point5athus allowing the kinematic storage mechanism52to store the energy on the basis of a first motion between the upper body3and the intermediate body5.

The first motion (FIG. 5a-5b) is provided by the movement of the first intermediate anchoring point5awith respect to the intermediate body5and controlled by the displacement of the upper dorsal attachment point3bwith respect to the intermediate body5. In use, such a motion occurs with the extension of the knee and more precisely at peak K4.

The loading cable54may be rigid and thus not flexible. Alternatively, it may be flexible.

The intermediate body5may comprise a discharging cable55connecting the lower anchoring point2ato the second intermediate anchoring point5bthus allowing the kinematic storage mechanism52to release the energy and cause motion of the lower body.

The discharging cable55may be rigid and thus not flexible. Alternatively, it may be flexible. In order to ensure the correct tensioning, the discharging cable55is flexible (especially in the case of flexible cable5), the intermediate body5may comprise a tensioner56adapted to adjust the tension of the discharging cable55irrespective of the position of the second intermediate anchoring point5bwith respect to the attachment51, and thus keeping the flexible discharging cable55taut, for example.

The discharging cable55may be rigid and thus not flexible. Alternatively, it may be flexible.

In order to ensure the correct tensioning, the discharging cable55is flexible (especially in the case of flexible cable5), the intermediate body5may comprise a tensioner56adapted to adjust the tension of the discharging cable55irrespective of the position of the second intermediate anchoring point5bwith respect to the attachment51, and thus keeping the flexible discharging cable55taut, for example.

Tensioner56is constrained to rotor523and, in detail, to an arm523a.

It may comprise a hinge561defining an additional rotational axis561a; an attachment562adapted to rotate about the additional rotation axis561ato which the second intermediate anchoring point5band said discharging cable55are constrained; and a preloaded spring engaged with the attachment562and controlling a rotation of the attachment562about the additional rotation axis561athus keeping the discharging cable55taut.

The additional rotation axis561ais substantially parallel to the rotation axis52a.

Hinge561is integral with rotor523, and in detail with an arm523a.

The preloaded spring is a spiral spring having one end integral with the hinge531and the other end integral with the attachment562.

In some cases, tensioner56may comprise a travel stop563against which the attachment562abuts during the energy release.

The travel stop563is integral with rotor523, and in detail with an arm523a. It also defines a radial extension of the constraining arm523aof the tensioner56adapted to limit the travel of the attachment562, and thus of the second intermediate anchoring point5b, in the releasing direction. In use, the travel stop563allows the release of energy to the lower body2only after the heel lifts from the ground.

The intermediate body5may comprise a releasing cable57connecting the upper ventral anchoring point3ato the third intermediate anchoring point5cin order to control the switching of the locking system53from the locking position to the releasing position due to a second motion between upper body3and intermediate body5.

The releasing cable57may be rigid and thus not flexible. Alternatively, it may be flexible.

The second motion is successive and not contingent on the first motion.

The second motion (FIG. 5d-5e) is given by the movement of the third intermediate anchoring point5cwith respect to the intermediate body5controlled by a displacement of the upper dorsal attachment point3awith respect to the intermediate body5. This second motion substantially starts with the bending of the knee and occurs at peak A2.

In order to release energy during this second motion, the locking system53may comprise a transmission pulley533of the releasing cable56conveniently hinged to the intermediate body5and, in detail, to the stator522.

Pulley533is on the opposite side with respect to the upper dorsal anchoring point3awith respect to the third intermediate anchoring point5c.

The invention identifies a new assisted-walking method that can be implemented by the wearable assisted-walking device1described above in structural terms.

The assisted-walking method comprises a step of loading (FIG. 4a-4b), in which the energy is stored in the kinematic storage mechanism52; and a step of releasing (FIG. 4d-4f), in which the energy is released to the lower body2by the kinematic storage mechanism52.

During the step of loading, there is a first motion between intermediate body5and upper body3, which tends to move the first intermediate anchoring point5aand the upper dorsal attachment point3baway from each other. In response to the first motion, the loading cable54is pulled and controls the rotation in the loading direction of rotor523with respect to stator522about the rotation axis52a.

More precisely, the loading cable54rotates the additional arms525awhich, by virtue of connector525b, rotate the arms523a, and thus the rotor523.

The rotation of the arms523apushes the storage unit524against the resting surface522aand the springs are compressed when storing energy.

During the rotation of the arms523ain the loading direction, tensioner56keeps the discharging cable55taut.

During the step of loading, the locking system53may be in locking position.

Having concluded the step of loading, the step of releasing (FIG. 4d-4e) may start, in which the second motion takes the locking system53from the locking position to the releasing position and thus the kinematic storage mechanism52(FIG. 4f) discharges the energy stored in the step of loading.

During the step of releasing, there is the second motion between intermediate body5and upper body3which tends to move the third intermediate anchoring point5aand the upper dorsal attachment point3bmutually away from each other. Therefore, the releasing cable57is pulled, and conveniently by virtue of the transmission defined by the pulley533, controls the release of the tooth532from the toothed wheel532and thus puts the locking system53in releasing position.

At this point, the rotation of rotor523in the releasing direction is no longer prevented by the locking system53and thus the storage unit524releases the stored energy by controlling the rotation of the arms523ain the releasing direction.

The loading cable55, being the second intermediate anchoring point5bfed by an arm523a, pulls the lower anchoring point2atowards the intermediate body5and thus promotes powered plantar-flexion of the ankle.

It is worth noting that between the step of loading and the step of releasing, the assisted-walking method advantageously comprises a step of storage (FIG. 4c) in which the locking system53, while remaining in the locking position, prevents the energy stored in the preceding step of loading from being discharged.

The wearable assisted-walking device1according to the invention achieves major advantages.

A first advantage is that the wearable device1identifies a solution for storing energy at a joint (the knee) and releases this energy at a different joint (the ankle) while not getting in the way of the user.

Such an aspect is allowed by the particular choice of the constraint points of the bodies2,3and5, and thus of the various anchoring points2a,3a,3b,5a,5band5cand by how they are connected by cables54,55and57.

Furthermore, this innovative technical solution allows one to take advantage of particular walking movements (more precisely, the peaks K4and A2) for the storage and return of energy.

Another advantage of the wearable device1is the utilization of large contributions of energy that are always present during walking. While passive devices cannot supply power capable of sufficiently helping the user, active devices require large motors and big batteries to provide this power, but are heavy, large and uncomfortable.

A further advantage1is that the wearable device1, by being passive (free from motors and batteries), is light and does not require electronic control.

The invention is susceptible to variants falling within the scope of the inventive concept defined by the claims. In such a scope, all the details can be replaced by equivalent elements and materials of any shape and size.