Patent Description:
It is known in the art a knee movement assistive device comprising a waist garment attachable to a user waist and a calf garment attachable to a user calf.

The known assistive device comprises an actuator attached to the waist garment and comprising a driver. Said driver is configured to switch between an active state, wherein the driver generates an actuation force, and an idle state, wherein the driver generates a null force.

In addition, the known assistive device comprises a transmission cable connecting the actuator to the calf garment and being configured to transmit the actuation force, generated by the driver, to the calf garment.

The actuation force transmitted to the calf garment assist the knee movement, for example, reducing the knee torque when the user is performing a squat.

<CIT>, which is regarded as being the closest prior art, discloses a knee movement assistive device, comprising: a waist garment attachable to a user waist and a calf garment attachable to a user calf, said calf garment being arranged along a longitudinal direction; an actuator attached to the waist garment and comprising a driver, said driver being configured to switch between an active state, wherein the driver generates a rotational force, and an idle state, wherein the driver generates a null force, the actuator being configured to transform the rotational force of the driver in a tension force; a transmission cable connecting the actuator to the calf garment and being configured to transmit the tension force, generated by transforming the rotational force of the driver, to foot-worn portions; said assistive device being configured in that it comprises: a chain comprising a modular body having a fixed end, attached to a lower frame, a free end and an upper surface connecting the fixed end and the free end, wherein: the chain is configured to switch between an initial configuration, wherein the fixed end and the free end of the modular body are at a first distance, and a limiting configuration, wherein the modular body is arranged along a curvature direction defining a curvature angle with respect to the longitudinal direction such that the fixed end and the free end of the modular body are at a second distance, said second distance being smaller than the first distance, the bending of the user knee switching the modular body of the chain between the initial configuration and the limiting configuration.

However, it is known that during the movement performed by a user wearing the known assistive device, undesired forces generated by the known assistive device act directly on the knee joint.

These forces interferes with the movement of the users, causing high discomfort for the user wearing the known assistive device. At the same time, said forces induce the user performing wrong movements, invalidating the rehabilitation exercise performed by the user.

In this context, the technical object of the present invention is to provide a knee movement assistive device which overcomes the drawbacks of the prior art.

Namely, the object of the present invention is to provide a stable knee movement assistive device that guarantee high comfort to the user wearing said assistive device.

The specifically technical object and the specified aims are substantially achieved by a knee movement assistive device comprising the technical characteristics described in the appended claims.

The knee movement assistive device described allows correctly assisting a user knee movement, guaranteeing high comfort to the user wearing said assistive device.

At the same time, the knee movement assistive device described reduces the risk of incorrect movements performed by the user wearing the assistive device.

Further characteristics and advantages of the present invention will appear more clearly form the description of a preferred embodiment of a knee movement assistive device as illustrated in the enclosed drawings in which:.

With reference to the attached figures, numeral <NUM> designates a knee movement assistive device.

The assistive device <NUM> comprises a waist garment <NUM> attachable to a user waist. For example, the waist garment <NUM> comprises at least one first buckle <NUM>. Preferably, the waist garment <NUM> comprises a couple of first buckles <NUM>. As is per se know to the skilled person, the first buckles <NUM> allows the waist garment <NUM> to be stably attached to a user waist. At the same time, the first buckles <NUM> allows to adjust the waist garment <NUM> according to the specific dimension of the user waist, increasing the comfort of the user wearing said waist garment <NUM>.

In addition, the assistive device <NUM> comprises a calf garment <NUM> attachable to a user calf. For example, the calf garment <NUM> comprises a couple of joint portions <NUM>. The joint portion <NUM> can be clamped to a user calf, stably attaching the calf garment <NUM> to the user calf.

The calf garment <NUM> is arranged along a longitudinal direction X-X. When the calf garment <NUM> is attached to a user calf, preferably, the longitudinal direction X-X overlaps to the direction defined by the user calf. Alternatively, when the calf garment <NUM> is attached to a user calf, the longitudinal direction X-X defines a small relative angle with respect to the direction defined by the user calf.

The assistive device <NUM> comprises an actuator <NUM> attached to the waist garment <NUM> and comprising a driver <NUM>. When the waist garment <NUM> is attached to a user waist, the actuator <NUM> is preferably arranged on a back side of the user. As it is known to the skilled person, the back side of the user is the one defined by the back of the user.

Accordingly, the driver <NUM> is configured to switch between an active state, wherein the driver <NUM> generates a rotational force, and an idle state, wherein the driver <NUM> generates a null force. In other words, in the idle state the driver <NUM> generates no rotational force.

The actuator <NUM> is configured to transform the rotational force of the driver <NUM> in a tension force.

According to a preferred feature, the assistive device comprises rechargeable battery being configured to supply power to the driver <NUM>.

Preferably, the assistive device <NUM> comprises a box <NUM>. The driver <NUM> and the rechargeable battery are arranged inside the box <NUM>. Also the box <NUM> is arranged on the back side of a user wearing the assistive device <NUM>.

In addition, the assistive device <NUM> comprises a transmission cable <NUM> connecting the actuator <NUM> to the calf garment <NUM> and being configured to transmit the tension force, generated by transforming the rotational force of the driver <NUM>, to the calf garment <NUM>. The tension force transmitted to the calf garment <NUM> assist the knee movement of a user. For example, the tension force, generated by transforming the rotational force of the driver <NUM> and transmitted to the calf garment <NUM>, provide assistive torque to the knee joint when the user is bending the knee.

Preferably, the transmission cable <NUM> has an upper end <NUM> connected to the actuator <NUM> and a lower end <NUM> connected to the calf garment <NUM>. Still preferably, the transmission cable <NUM> corresponds to a Bowden cable.

Still preferably, the transmission cable <NUM> comprises a cover housing <NUM> and inner cable <NUM> at least in part slidably channeled in the cover housing <NUM>.

According to the preferred embodiment of the invention, the actuator <NUM> comprises a first gear <NUM> connected to the driver <NUM> and being configured to rotate around a first rotation center. The rotational force generated by the driver <NUM> makes the first gear <NUM> rotate around the first rotation center. In other words, when the driver <NUM> is in the active state the first gear <NUM> rotates around the first rotation center.

Still according to the preferred embodiment of the invention, the actuator <NUM> comprises a second gear <NUM> operatively engaging the first gear <NUM> and being configured to rotate around a second rotation center. The transmission cable <NUM> is connected to the second gear <NUM>. For example, the actuator <NUM> comprises a pulley <NUM> connected to the second gear <NUM> and the inner cable <NUM> of the transmission cable <NUM> is connected to the pulley <NUM>.

According to the preferred embodiment of the invention, the actuator <NUM> comprises locking means <NUM> operatively engaging the first <NUM> and the second <NUM> gears.

Preferably, the first gear <NUM>, the second gear <NUM> and the locking means <NUM> are mounted on a sidewall <NUM> of the box <NUM>.

According to a preferred feature, the locking means <NUM> are configured to switch between a locking configuration and a releasing configuration.

Preferably, In the locking configuration of the locking means <NUM>, the second gear <NUM> is prevented to rotate around the second rotation center.

Still preferably, in the releasing configuration of the locking means <NUM>, the rotation of the first gear <NUM> makes the second gear <NUM> rotate around the second rotation center so that the rotational force generated by the driver <NUM> is transformed in the tension force and can be transmitted to the calf garment <NUM> through the transmission cable <NUM>. In fact, being the inner cable <NUM> of the transmission cable <NUM> attached to the second gear <NUM>, the rotation of the second gear <NUM> pulls the transmission cable <NUM> or release the pull action on the transmission cable <NUM>. In other words, depending on the specific rotation direction of the second gear <NUM>, the rotational force of the driver <NUM> is transformed in a first tension force acting as pull force or in a second tension force acting as a releasing force. The second tension force progressively release the first tension force, namely release the pull action transmitted to the calf garment <NUM>. In other words, the second tension force is opposite to the first tension force.

Still preferably, the locking means <NUM> are configured to switch from the locking configuration to the releasing configuration due to the rotation of the first gear <NUM> when the driver <NUM> is in the active state. Therefore, when the driver <NUM> is in the active state, the tension force can be transmitted to the calf garment <NUM> to assist the user knee movement.

Still preferably, the locking means <NUM> are configured to automatically switch from the releasing configuration to the locking configuration when the driver <NUM> is switched to the idle state. Therefore, when the driver <NUM> is switched to the idle state, being the locking means <NUM> in the locking configuration, the tension force generated from the rotational force of the driver <NUM> is still transmitted to the calf garment <NUM>, without needing to maintain the driver <NUM> in the active state. In other words, after the desired tension force has been transmitted to the calf garment <NUM>, the driver <NUM> can be switched to the idle state letting the desired tension force still act on the calf garment <NUM>.

As a result, after the desired tension force is transmitted to the calf garment <NUM>, the driver <NUM> can be switched to the idle state continuing assisting the user knee movement and reducing, therefore, the overall energy needed to assist the user knee movement with the assistive device <NUM>.

According to a preferred embodiment of the invention, the first gear <NUM> has a first perimetral wall <NUM>, arranged on a first circumferential direction. Namely, the first gear <NUM> has a circular shape.

In addition, the first gear <NUM> has a plurality of first teeth <NUM> arranged on said first perimetral wall <NUM>. Preferably, the firs teeth <NUM> are equally spaced apart from each other along the first circumferential direction. The rotation of the first gear <NUM> around the first rotation center making the first teeth <NUM> move along the first circumferential direction. In other words, when the driver <NUM> is in the active state, the first teeth <NUM> move along the first circumferential direction.

Preferably, the first teeth <NUM> has a wedge shape. Still preferably, the first gear <NUM> has fifteen first teeth <NUM>.

Still according to the preferred embodiment of the invention, the second gear <NUM> has a second perimetral wall <NUM>, arranged on a second circumferential direction. Namely, also the second gear <NUM> has a circular shape.

In addition, the second gear <NUM> has a plurality of second teeth <NUM> arranged on the second perimetral wall <NUM>. Preferably, the second teeth <NUM> are equally spaced apart from each other along the second circumferential direction. The rotation of second gear <NUM> around the second rotation center making the second teeth <NUM> move along the second circumferential direction.

Preferably, the second gear <NUM> has twenty-five second teeth <NUM>.

Accordingly, the rotation of the first gear <NUM> in the releasing configuration of the locking means <NUM> makes each first tooth <NUM> progressively engage a respective second tooth <NUM> making the second gear <NUM> rotate around the second rotation center.

Still preferably, the first gear <NUM> is configured to clockwise and anticlockwise rotate due to the rotational force generated by the driver <NUM>. It should be noted that, due to the progressively engagement of each first tooth <NUM> with a respective second tooth <NUM>, the clockwise rotation of the first gear <NUM> is transformed in an anticlockwise rotation of the second gear <NUM>, while the anticlockwise rotation of the first gear <NUM> is transformed in a clockwise rotation of the second gear <NUM>. Namely, the rotation direction of the first gear <NUM> is preferably opposite to the rotation direction of the second gear <NUM>.

It should be noted that, for example, an anticlockwise rotation of the second gear <NUM> transformed the rotational force of the driver <NUM> in the first tension force, pulling the transmission cable <NUM>, while a clockwise rotation of the second gear <NUM> transform the rotational force of the driver <NUM> in the second tension force, releasing the pull action on the transmission cable <NUM>.

According to a preferred feature, each couple of second teeth <NUM> is spaced apart by a respective separation distance along the second circumferential direction. Said separation distance is greater than the thickness of each first tooth <NUM> along the first circumferential direction.

Given that the separation distance is greater than the thickness of each first tooth <NUM>, at least one first tooth <NUM> is interposed between a couple of second teeth <NUM> and is spaced apart from each of said second teeth <NUM> in the locking configuration of the locking means <NUM>. The rotational force of the driver <NUM> makes said first tooth <NUM> engaging one of said second teeth <NUM>.

Therefore, before at least one first tooth <NUM> engages a second tooth <NUM>, the rotation of the first gear <NUM>, due to the rotational force of the driver <NUM>, switches the locking means <NUM> from the locking configuration to the releasing configuration. Namely, the locking means <NUM> are switched from the locking configuration to the releasing configuration before the first gear <NUM> makes the second gear <NUM> to rotate around the second rotation center. In this way, no rotation of the second gear <NUM> occurs when the locking means <NUM> are in the locking configuration.

According to the preferred embodiment of the invention, the locking means <NUM> comprises a stopper <NUM> having a first engagement portion <NUM>. Preferably, the first engagement portion <NUM> has a tip shape.

The stopper <NUM> is configured to assume in the locking configuration of the locking means <NUM> a locking position, wherein the first engagement portion <NUM> engages at least one second tooth <NUM>. Preferably, in the locking position, the first engagement portion <NUM> is inserted between a couple of second teeth <NUM>. Therefore, when the stopper <NUM> is in the locking position the second gear <NUM> cannot rotate around the second rotation center.

At the same time, the stopper <NUM> is configured to assume in the releasing configuration of the locking means <NUM> a releasing position, wherein the first engagement portion <NUM> is spaced apart from the second gear <NUM> along a direction transverse to the second circumferential direction. It should be noted that, when the locking means <NUM> are in the releasing configuration the stopper <NUM> is almost always in the releasing position so that the second gear <NUM> can rotate around the second rotation center without risking that a second tooth <NUM> engages the first engagement portion <NUM>. However, it could happen that in the releasing configuration of the locking means <NUM> a second tooth <NUM> hits the first engagement portion <NUM>, but without stopping the rotation of the second gear <NUM>.

Preferably, the locking means <NUM> is configured to assume an intermediate configuration between the releasing configuration and the locking configuration. In said intermediate configuration, the engagement portion <NUM> of the stopper <NUM> is inserted between a couple of second teeth <NUM> and is spaced apart from said second teeth <NUM>. The passive clockwise rotation of the second gear <NUM> when the locking means <NUM> are in the intermediate configuration and the driver <NUM> is in the idle state makes at least one second tooth <NUM> engage the first engagement portion of the stopper <NUM>, switching the locking means <NUM> in the locking configuration, locking the rotation of the second gear <NUM>.

According to the preferred embodiment of the invention, the locking means <NUM> comprises a lever <NUM>. The lever <NUM> is configured to rotate around a third rotation center.

The lever <NUM> extends between a second engagement portion <NUM> and an opposite thrust portion <NUM> along an axis of the lever <NUM> passing through the third rotation center. Preferably, the thrust portion <NUM> has a tip shape.

The thrust portion <NUM> engages the stopper <NUM>. Preferably, the thrust portion <NUM> engages a receiving portion <NUM> of the stopper <NUM>.

It should be noted that, the rotation of the first gear <NUM> due to the rotational force of the driver <NUM> makes the first gear <NUM> to engage the lever <NUM> at the second engaging portion <NUM> to put the lever <NUM> in rotation around the third rotation center. At the same time, the rotation of the lever <NUM> around the third rotation center makes the thrust portion <NUM> exert a thrust action on the stopper <NUM> to switch the stopper <NUM> from the locking position to the releasing position. Namely, due to the rotation of the lever <NUM> the thrust portion <NUM> exerts a thrust action on the receiving portion <NUM> of the stopper <NUM>, displacing the first engagement portion <NUM> away from the second gear <NUM>.

When the driver <NUM> is switched to the idle state, namely when the first gear <NUM> stops rotating, the thrust portion <NUM> stops exerting a thrust action on the stopper <NUM>, making the first engagement portion <NUM> to progressively approach the second gear <NUM>. In other words, after the driver <NUM> is switched to the idle state, the locking means <NUM> can switch from the releasing configuration to the locking configuration or to the intermediate configuration and then to the locking configuration.

Preferably, the locking means <NUM> comprises a spring <NUM> acting on the stopper <NUM>. The spring <NUM> makes the first engagement portion <NUM> to progressively engage the second gear <NUM>, when the driver <NUM> is switched to the idle state. In fact, the spring <NUM> always exert a pushing action on the first engagement portion <NUM> pushing said first engagement portion <NUM> against the second gear <NUM>. When the driver <NUM> is switched to the active state, the thrust action of the thrust portion <NUM> acting on the stopper <NUM> wins the pushing action of the spring <NUM>, displacing the first engagement portion <NUM> away from the second gear <NUM>. When, the driver <NUM> is switched to the idle state, the thrust portion <NUM> stops exerting a thrust action on the stopper <NUM>, so that the pushing action of the spring <NUM> makes the first engagement portion <NUM> to progressively engage the second gear <NUM>.

It should be noted that, preferably, the thrust portion <NUM> of the lever <NUM> remains in contact with the stopper <NUM> both when the locking means <NUM> are in the locking configuration and in the releasing configuration, but also during the switching of the locking means <NUM> between the locking configuration and the releasing configuration.

It should be noted that, during the rotation of the first gear <NUM>, the first teeth <NUM> engages one by one the lever <NUM> at the second engagement portion <NUM>, making the lever <NUM> to rotate around the third rotation center.

It should also be noted that, preferably, the clockwise rotation of the first gear <NUM> makes the first gear <NUM> engage the second engagement portion <NUM> in a first contact area to anticlockwise rotate the lever <NUM>. Namely, the first teeth <NUM> engage the second engagement portion <NUM> in the first contact area.

At the same time, still preferably, the anticlockwise rotation of the first gear <NUM> makes the first gear <NUM> to engage the second engagement portion <NUM> in a second contact area to anticlockwise rotate the lever <NUM>. Namely, the first teeth <NUM> engage the second engagement portion <NUM> in the second contact area.

Preferably, the rotation of the first gear <NUM> around the first rotation center makes always the lever <NUM> to anticlockwise rotate around the third rotation center so that the thrust portion <NUM> exert the thrust action on the stopper <NUM>. Namely, when the driver <NUM> is in the active state, both the clockwise and the anticlockwise rotation of the first gear <NUM> switch the locking means <NUM> from the locking to the releasing configuration. In this way, the rotational force generated by the driver <NUM> in the active state is always transferred to the calf garment <NUM> in order to assist the knee movement, given that the second gear <NUM> can freely rotate around the second rotation center.

Preferably, the first contact area and second contact area are spaced apart from each other along the axes of the lever <NUM>. Still preferably, the distance of the first contact area from the third rotation center along the axes of the lever <NUM> is smaller than the distance of the second contact area from the third rotation center along the axes of the lever <NUM>.

According to the preferred embodiment of the invention, the second engagement portion <NUM> of the lever <NUM> has a curved edge <NUM> facing the first gear <NUM>. The curved edge <NUM> has a recessed portion <NUM> and a rounded portion <NUM>. Preferably, the first contact area is placed on the left side of the rounded portion <NUM>, while the second contact area is placed on the right side of the rounded portion <NUM>.

It should be noted that, preferably, the anticlockwise rotation of the lever <NUM> makes the stopper <NUM> to clockwise rotate around a fourth rotation center so that it is displaced from the locking position to the releasing position. Namely, following the rotation of the first gear <NUM> in the active state of driver <NUM>, the stopper <NUM> clockwise rotate around the fourth rotation center. It should also be noted that, when the driver <NUM> is switched from the active state to the idle state, the stopper <NUM> automatically anticlockwise rotates around the fourth rotation center so that the locking means <NUM> can be switched from the releasing configuration to the intermediate configuration or to the locking configuration.

Preferably, the first engagement portion <NUM> and the receiving portion <NUM> of the stopper <NUM> are opposite to each other with respect to the fourth rotation center.

According to the preferred embodiment of the invention, the stopper <NUM> and the lever <NUM> have the shape reported in <FIG>. The shape of the stopper <NUM> and the lever <NUM> is partially visible also in <FIG>.

According to the preferred embodiment of the invention, the actuator <NUM> comprises a control unit in signal communication with the driver <NUM> and with an external device. The control unit is configured to switch the driver <NUM> between the idle state and the working state upon receival of a command signal by the control unit coming from the external device. In other words, it is possible to actively control the driver <NUM> so that the tension force is transmitted to the calf garment <NUM> by means of an external device, assisting the user knee movement.

According to the invention, the assistive device <NUM> comprises a chain <NUM>. Preferably, the chain <NUM> is interposed between the waist garment <NUM> and the calf garment <NUM>. Still preferably, when a user is wearing the assistive device <NUM>, the chain is arranged on a front side of the user. As it per se known to the skilled person, the front side of a user is opposite to the back side of the user.

The chain <NUM> comprises a modular body <NUM> having a fixed end <NUM>, attached to the calf garment <NUM>, a free end <NUM> and an upper surface <NUM> connecting the fixed end <NUM> and the free end <NUM>. Preferably, the free end <NUM> is facing the waist garment <NUM>. When a user is wearing the assistive device <NUM>, the upper surface is facing away with respect to the leg of the user.

The modular body <NUM> comprises a groove <NUM> defined on the upper surface <NUM>. The transmission cable <NUM> is slidably channeled in the groove <NUM>. Preferably, only the inner cable <NUM> of the transmission cable <NUM> is slidably channeled in the groove <NUM>. Being the transmission cable <NUM> slidably channeled in the groove <NUM>, the transmission cable <NUM> can transmit the tension force to the calf garment <NUM>.

The chain <NUM> is configured to switch between a an initial configuration and a limiting configuration.

In the initial configuration of the chain <NUM>, the fixed end <NUM> and the free end <NUM> of the modular body <NUM> are at a first distance. Preferably, the first distance is the maximum distance between the fixed end <NUM> and the free end <NUM>.

In the limiting configuration of the chain, the modular body <NUM> is arranged along a curvature direction Y-Y defining a curvature angle with respect to the longitudinal direction X-X such that the fixed end <NUM> and the free end <NUM> of the modular body <NUM> are at a second distance. The second distance is smaller than the first distance. Namely, when the chain <NUM> is in the limiting configuration the fixed end <NUM> and the free end <NUM> are spaced apart from each other along the curvature direction Y-Y. Preferably, the second distance is the minimum distance between the fixed end <NUM> and the free end <NUM>.

The bending of the user knee switches the modular body <NUM> of the chain <NUM> between the initial configuration and the limiting configuration. In other word, the modular body <NUM> of the chain <NUM> follows the bending of the knee of the user wearing the assistive device <NUM>.

It should be noted that, preferably, when a user is wearing the assistive device <NUM> and the chain <NUM> is switched from the initial configuration to the limiting configuration it means that the user is assisted in moving from a stand up position to a bent position. At the same time, still preferably, when the user is wearing the assistive device <NUM> and the chain <NUM> is switched from the limiting configuration to the initial configuration it means that the user is assisted in moving from a bent position to a stand up position.

It should be noted that, given that the chain <NUM> guides the transmission cable <NUM> during the knee movement, the chain <NUM> avoids applying any force directly on the knee joint of the user wearing the assistive device <NUM>. Therefore, the chain <NUM> avoids interferences and discomfort during use of the assistive device <NUM>.

At the same time, the chain <NUM> generates a fully deterministic assistive torque, due to the switching of the chain <NUM> from the initial configuration to the limiting configuration that permits to route the transmission cable <NUM> along a desired path around the knee joint of the user wearing the assistive device <NUM>.

Therefore, the chain <NUM> is used to guide the transmission cable <NUM> and optimize the moment arm to generate the desired assistive torque and knee flexion angle profile. In order words, the chain <NUM> contributes in assisting the user knee movement.

According to the preferred embodiment of the invention, the modular body <NUM> of the chain <NUM> comprises at least one modular unit. Each modular unit comprises a first and a second rigid elements <NUM> connected together to define, at least in part, the groove <NUM> of the modular body <NUM>. Preferably, each rigid element <NUM> comprises a respective portion of the groove <NUM> of the modular body <NUM> and the joining of all said portions defines the groove <NUM>.

Preferably, the modular body <NUM> comprises five rigid elements <NUM> arranged in four modular units. In fact, if a rigid element <NUM> is interposed between other two rigid elements <NUM>, it belongs to two different modular units. In other words, if a rigid element <NUM> is interposed between other two rigid elements <NUM>, said rigid element <NUM> defines a first modular unit, wherein it works as a second rigid element <NUM>, with the preceding rigid element <NUM>, and it defines a second modular unit, wherein it works as first rigid element <NUM>, with the succeeding rigid elements <NUM>. Namely, each rigid element <NUM> defines a respective modular unit with each adjacent rigid element <NUM>.

Still preferably, each rigid element <NUM> is arranged along the curvature direction Y-Y and extends between a first edge <NUM> and an opposite second edge <NUM> with respect to the curvature direction Y-Y.

The first and the second rigid elements <NUM> of each modular unit are connected together such that in the initial configuration of the chain <NUM> the second edge <NUM> of the first rigid element <NUM> and the first edge <NUM> of the second rigid element <NUM> are facing together and spaced apart from each other. Namely, being the second edge <NUM> of the first rigid element <NUM> and the first edge <NUM> of the second rigid element <NUM> spaced apart from each other in the initial configuration of the chain <NUM>, the fixed end <NUM> and the free end <NUM> of the modular body <NUM> are, preferably, at the maximum distance between each other.

At the same time, the first and the second rigid elements <NUM> of each modular unit are connected together such that in the limiting configuration of the chain <NUM> the second edge <NUM> of the first rigid element <NUM> and the first edge <NUM> of the second rigid element <NUM> are in contact making the modular body <NUM> of the chain <NUM> to be arranged along the curvature direction Y-Y. In fact, given that each rigid element is arranged along the curvature direction Y-Y, in the limiting configuration also the whole modular body <NUM> defined by the rigid elements <NUM> is arranged along the curvature direction Y-Y.

Therefore, switching from the initial configuration to the limiting configuration the fixed end <NUM> and the free end <NUM> of the modular body <NUM> progressively approaching to reach the minimum distance at the limiting configuration.

Accordingly to the preferred embodiment of the invention, each rigid element <NUM> extends between a base <NUM> and an opposite top <NUM> with respect to a direction transverse to the curvature direction Y-Y.

In addition, each rigid element <NUM> has at least one through hole <NUM> placed near the top <NUM>. Preferably, each rigid element <NUM> has one trough hole <NUM> for each modular unit to which it belongs. Still preferably, the through holes <NUM> of each rigid element <NUM> are placed above the respective portion of the groove <NUM> of said rigid element <NUM>.

Moreover, preferably, the chain <NUM> comprises one pin <NUM> for each modular unit. Each pin <NUM> is inserted in the through holes <NUM> of the first and second rigid elements <NUM> of a respective modular unit connecting the first and second rigid elements <NUM> of said modular unit together. Namely, the first and second rigid elements <NUM> of each modular units are hinged together at a connection point resulting from the overlapping of the through holes <NUM> of the first and second rigid elements <NUM> of said modular unit.

It should be noted that during the switching from the initial configuration to the limiting configuration of the chain <NUM>, the first and the second rigid elements <NUM> of each respective modular unit are approaching each other by rotating around their respective connection point.

According to the preferred embodiment of the invention, the modular body <NUM> of the chain <NUM> comprises a first portion <NUM> placed near the fixed end <NUM> and a second portion <NUM> placed near the free end <NUM>.

Preferably, the first portion <NUM> of the chain <NUM> is arranged along a portion of an ellipse and the second portion <NUM> of the chain <NUM> is arranged along a portion of a circle internally tangent to the ellipse in a tangent point when the chain <NUM> is in the limiting configuration. Given this specific arrangement of the first <NUM> and second <NUM> portions of the chain <NUM>, there is no interaction between the human knee and the chain <NUM>.

It should also be noted that, by changing the parameters of the ellipse and of the circle internally tangent to the ellipse, different profiles of the chain <NUM> in the limiting configuration can be obtained. By changing the profile of the chain <NUM> in the limiting configuration, the performance of the assistive device <NUM> can be optimized and, at the same time, it can be adapted to different users.

According to the preferred embodiment of the invention, the calf garment <NUM> extends between a bottom portion <NUM> and an opposite top portion <NUM> along the longitudinal direction X-X. When a user is wearing the assistive device <NUM>, the bottom portion <NUM> of the calf garment <NUM> is placed near the ankle of the user.

Preferably, the calf garment <NUM> comprises an elastic element <NUM> extending between a first end <NUM> and an opposite second end <NUM> along the longitudinal direction X-X. For example, the elastic element <NUM> is a rubber belt. Still preferably, when a user is wearing the assistive device <NUM>, the elastic element is arranged on the front side of a user.

Still preferably, the transmission cable <NUM> is connected to the first end <NUM> of the elastic element <NUM>. More preferably, the lower end <NUM> of the transmission cable <NUM> is connected to the first end <NUM> of the elastic element <NUM>. For example, the first end <NUM> of the elastic element <NUM> comprises an end connector <NUM>. It should be noted that, preferably, the lower end <NUM> of the transmission cable <NUM> is defined on its inner cable <NUM>. At the same time, preferably, the upper end <NUM> of the transmission cable <NUM> is defined on its inner cable <NUM>.

Preferably, the second end <NUM> of the elastic element <NUM> is connected to the bottom portion <NUM> of the calf garment <NUM>. Namely, the elastic element <NUM> connects the lower end <NUM> of the transmission cable <NUM> to the bottom portion <NUM> of the calf garment <NUM>.

Still preferably, the fixed end <NUM> of the modular body <NUM> of the chain <NUM> is attached to the top portion <NUM> of the calf garment <NUM>.

According to a preferred feature, the elastic element <NUM> is configured to switch between a rest configuration and an extended configuration, the distance between the first <NUM> and the second <NUM> ends along the longitudinal direction X-X increasing from the rest configuration to the extended configuration.

As already described, the actuator <NUM> is configured to transform the rotational force of the driver <NUM> in a first tension force, acting as a pull force, and in a second tension force, acting as a releasing force. The first tension force transmitted to the calf garment <NUM> is configured to switch the elastic element <NUM> from the rest configuration to the extended configuration. At the same time, the second tension force transmitted to the calf garment <NUM> is configured to allow the elastic element <NUM> to switch from the extended to the rest configuration due to the elastic return of the elastic element <NUM>.

It should be noted that, preferably, as the tension force generated by the actuator <NUM> switch the elastic element <NUM> from the rest to the extend configuration and as the user wearing the assistive device <NUM> switches from a stand up position to a bent position, the chain <NUM> is simultaneously switched from the initial configuration to the limiting configuration. At the same time, as the tension force generated by the actuator <NUM> allow the elastic element <NUM> to switch from the extended configuration to the rest configuration and as the user wearing the assistive device <NUM> switches from a bent position to a stand up position, the chain <NUM> is simultaneously switched from the limiting configuration to the initial configuration.

It should be also noted that, when a user is wearing the assistive device <NUM> and the elastic element <NUM> is in the rest configuration the user is in a stand up position. On the other hand, when the elastic element <NUM> is in the extended configuration the user is in a bent position. In other word, by switching the elastic element <NUM> from the rest configuration to the extended configuration and viceversa, the user is assisted in doing, for example, a squat.

According to the preferred embodiment of the invention, the assistive device <NUM> comprises a thigh garment <NUM> attachable to a user thigh. For example, the thigh garment <NUM> comprises at least one second buckle <NUM>. Preferably, the thigh garment <NUM> comprises three second buckles <NUM>. As is per se know to the skilled person, the second buckles <NUM> allows the thigh garment <NUM> to be stably attached to a user thigh. At the same time, the second buckles <NUM> allows to adjust the thigh garment <NUM> according to the specific dimension of the user thigh, increasing the comfort of the user wearing said thigh garment <NUM>.

As the thigh garment <NUM> is attachable to a user thigh, when the user is wearing the assistive device <NUM>, the thigh garment <NUM> is interposed between the waist garment <NUM> and the calf garment <NUM>.

Preferably, the thigh garment <NUM> comprises a support element <NUM>. When a user is wearing the thigh garment <NUM>, the support element <NUM> is placed on the front side of a user.

The transmission cable <NUM> is slidably channeled in the support element <NUM>. Advantageously, the support element <NUM> of the thigh garment allows a better transmission of the tension force generated by the actuator <NUM> to the calf garment <NUM>.

Preferably, the cover housing <NUM> of the transmission cable <NUM> connects the box <NUM> to the support element <NUM>. In other word, preferably, the inner cable <NUM> of the transmission cable <NUM> is channeled in the cover housing <NUM> only between the box <NUM> and the support element <NUM>.

Still preferably, the free end <NUM> of the modular body <NUM> of the chain <NUM> faces the thigh garment <NUM>. Namely, the chain <NUM> is configured to be interposed between the thigh garment <NUM> and the calf garment <NUM>.

According to the preferred embodiment of the invention, the thigh garment <NUM> comprises a body portion <NUM> having a plurality of first joining elements <NUM>. Preferably, the support element <NUM> comprises a plate <NUM> having a plurality of second joining elements <NUM>. Each second joining element <NUM> is connected to a respective first joining element <NUM> to stably attach the support element <NUM> to the body portion <NUM> of the thigh garment <NUM>. By disconnecting the second joining elements <NUM> and the first joining elements <NUM> it is possible to remove the support element <NUM> from the body portion <NUM> of the thigh garment <NUM>.

For example, each first joining element <NUM> correspond to a strap or a belt, while each second joining element <NUM> corresponds to a fin insertable in a respective strap or a slot configured to receive a respective belt.

Still according to the preferred embodiment of the invention, the assistive device <NUM> comprises a plurality of first elastic robs <NUM> connecting the waist garment <NUM> to the thigh garment <NUM>. Therefore the first elastic robs <NUM> prevents the sliding down of the thigh garment <NUM> with respect to the waist garment <NUM> during the use of the assistive device <NUM>. Therefore, the first elastic robs <NUM> increase the comfort of a user wearing the assistive device <NUM>.

According to the preferred embodiment of the invention, both the waist garment <NUM> and the thigh garment <NUM> comprises a plurality of respective second elastic robs <NUM>. Each second elastic rob <NUM> is disposed transversally to the first elastic robs <NUM>. It should be noted that the second elastic rob <NUM> of the waist garment <NUM> are used to maintain the shape of the waist garment <NUM> when a user is wearing the assistive device <NUM>. At the same time, the second elastic rob <NUM> of the thigh garment <NUM> are used to maintain the shape of the thigh garment <NUM> when a user is wearing the assistive device <NUM>.

According to a preferred embodiment, the assistive device comprises first straps <NUM> and second straps <NUM> connecting the waist garment <NUM> to the thigh garment <NUM>. Preferably, when a user is wearing the assistive device <NUM> the first straps <NUM> are arranged on the front side of the user, while the second straps <NUM> are arranged on the back side of the user. Both the first straps <NUM> and the second straps <NUM> are arranged in a triangular shape, with one attachment point on the thigh garment <NUM> and two attachments points on the waist garment <NUM>.

It should be noted that, the first straps <NUM> defines a first trace A for the load distribution, while the second straps <NUM> together with the thigh garment <NUM> defines a second trace B for the load distribution. Advantageously, the first <NUM> and second <NUM> straps can provide a stable support for the transmission cable <NUM> and distribute the high tension force to the upper thigh and hip of the user wearing the assistive device <NUM>. For example, if a user wearing the assistive device <NUM> is performing a squat motion, the load distribution switches between the first trace A and a second trace B.

At the beginning of squat, the first trace A will deliver the load to the waist garment <NUM> while the second trace B is loose. With the increase of the squat depth, the first trace A gradually becomes loose and the tension load will deliver to the backside of the waist garment <NUM> via the second trace B that has the additional benefit of also generating a positive torque around the hip supporting this joint during deep squat and during the transition from a squat to a standing posture.

It is also an object of the present invention, an exoskeleton comprising two assistive devices <NUM> corresponding to the assistive device <NUM> described above. Each assistive device <NUM> of the exoskeleton is used to assist the movement of a corresponding user knee.

Claim 1:
A knee movement assistive device (<NUM>), comprising:
- a waist garment (<NUM>) attachable to a user waist and a calf garment (<NUM>) attachable to a user calf, said calf garment (<NUM>) being arranged along a longitudinal direction (X-X);
- an actuator (<NUM>) attached to the waist garment (<NUM>) and comprising a driver (<NUM>), said driver (<NUM>) being configured to switch between an active state, wherein the driver (<NUM>) generates a rotational force, and an idle state, wherein the driver (<NUM>) generates a null force, the actuator (<NUM>) being configured to transform the rotational force of the driver in a tension force;
- a transmission cable (<NUM>) connecting the actuator (<NUM>) to the calf garment (<NUM>) and being configured to transmit the tension force, generated by transforming the rotational force of the driver (<NUM>), to the calf garment (<NUM>);
said assistive device (<NUM>) being configured in that it comprises:
- a chain (<NUM>) comprising a modular body (<NUM>) having a fixed end (<NUM>), attached to the calf garment (<NUM>), a free end (<NUM>) and an upper surface (<NUM>) connecting the fixed end (<NUM>) and the free end (<NUM>), said modular body (<NUM>) comprising a groove (<NUM>) defined on said upper surface (<NUM>), the transmission cable (<NUM>) being slidably channeled in said groove (<NUM>);
and wherein:
- the chain (<NUM>) is configured to switch between an initial configuration, wherein the fixed end (<NUM>) and the free end (<NUM>) of the modular body (<NUM>) are at a first distance, and a limiting configuration, wherein the modular body (<NUM>) is arranged along a curvature direction (Y-Y) defining a curvature angle with respect to the longitudinal direction (X-X) such that the fixed end (<NUM>) and the free end (<NUM>) of the modular body (<NUM>) are at a second distance, said second distance being smaller than the first distance, the bending of the user knee switching the modular body (<NUM>) of the chain (<NUM>) between the initial configuration and the limiting configuration.