FR3139988A1 - PASSIVE EXOSKELETON FOR SPINAL RELIEF - Google Patents

Abstract

TITLE OF THE INVENTION: PASSIVE EXOSKELETON FOR SPINAL RELIEF The exoskeleton (10) for a user (11) of predetermined morphology, comprises an abdominal belt (12) configured to surround the pelvis of this user and a pectoral harness (13). For each shoulder of the user, the exoskeleton comprises at least one spring rod (15) working in buckling and/or flexion, each spring rod being connected: - to a first end, to this pectoral harness and - to a second extremity, at the abdominal girdle. Each spring rod has a length configured such that, when the user wears the exoskeleton, the spring rod takes the form of an arc passing behind the user's back and exerts a restoring force tending to lift the thorax away from the user and away from their abdomen. Figure for abstract: Fig. 1

Description

PASSIVE SPINAL RELIEF EXOSKELETON Technical field of the invention

The present invention relates to a passive exoskeleton for relieving the spinal column. It falls within the field of assistance to people suffering from spinal ailments or back pain, whether at rest or during exercise, or in outpatient therapy.

State of the art

The present invention relates to a spinal decompression device. It finds in particular an application for relieving people suffering from back pain, caused for example by a herniated disc. Such pain occurs, among other things, because the vertebrae excessively compress the intervertebral discs separating them from each other. Furthermore, lower back pain, the leading cause of work stoppage in France, is caused by a traumatic event such as a bad movement during a move. For some patients, healing does not occur, the pain returns and the fear of it accentuates it.

Relief can be obtained by exerting a distraction effort on the spine, so as to decoapt the vertebrae, that is to say increase the interarticular space between two surfaces that are too close to each other.

Spinal decompression devices are known for exerting a distraction force on the user's spine. Such a device is for example proposed by document EP 0 319 224, which describes a spinal decompression device that surrounds a part of the trunk of a user, comprising an upper support, a lower support, two telescopic bars mounted on the lower and upper supports so as to exert a spreading force on the lower and upper supports. The telescopic bars comprise an actuating lever by means of which a third party, such as a health professional, can, when the device is worn by the user, move the lower and upper supports away from each other, to exert a distraction force on the user's spine. However, such a device is particularly heavy and bulky, and cannot be worn under clothing. Furthermore, it significantly reduces the mobility of the user, so that it cannot be worn for more than a few minutes. Furthermore, it must be installed and operated with the help of a third party. It also does not allow the spreading force exerted by the telescopic bars to be adapted, for example according to the movements made by the user, so that, for example when the user moves, the distraction effort varies, which tends to limit the relief allowed by the device.

Other devices, or exoskeletons, similar to those described above also include an electronic circuit for actuating the telescopic bars, or pistons. These devices also have the disadvantage of requiring an electrical power supply.

There are mainly two types of exoskeleton, the robotic or "active" exoskeleton and the "passive" exoskeleton. The robotic exoskeleton aims to significantly increase the strength of the operator wearing it, but it has the disadvantage of requiring a power source and at least one actuator, which increases the weight of the exoskeleton or, in the case where it is connected to an external power source, limits the user's ability to move. Conversely, the passive exoskeleton aims to reduce the effort required by the operator and does not consume energy. In particular, the passive exoskeleton is part of an approach to reducing the arduousness of performing repetitive and/or demanding work while preventing the onset of musculoskeletal disorders (MSDs).

The present invention aims to remedy all or part of these drawbacks.

To this end, according to a first aspect, the present invention aims at an exoskeleton for a user of predetermined morphology, comprising an abdominal belt configured to surround the pelvis of this user, a pectoral harness and, for each shoulder of the user, at least one spring rod working in buckling and/or flexion, each spring rod being connected:
- at a first end, to this pectoral harness and
- at a second end, at the abdominal belt;

the spring rod having a length configured such that, when the user wears the exoskeleton, the spring rod takes the shape of an arc passing behind the user's back and exerts a restoring force tending to lift the user's thorax and move it away from his abdomen.

By means of these provisions, the user's spine is relieved of part of the weight of the user's thorax and upper limbs. In addition, each spring rod associated with a shoulder being, at least partially, independent of another spring rod associated with another shoulder, the user can perform, without discomfort, flexion and twisting movements of his torso.

In embodiments, at least one spring rod is, at rest, a straight rod. The inventor has discovered that, in this case, the force exerted by the spring rod parallel to its chord is substantially constant during the arc deformation of the spring rod.

In embodiments, the chest harness is configured to surround the user's thorax below the xiphoid process.

Thanks to these provisions, the support of the rib cage is reinforced.

In embodiments, the chest harness comprises, for each shoulder, a strap configured to surround this shoulder, the connection between each spring rod and the chest harness being made on a strap and being positioned above this strap, that is to say in a position further from the abdominal belt than the strap.

In these embodiments, the spring rods have a length greater than the distance between the user's hips and collarbones. Thanks to these arrangements, the user's armpit remains free to move since this connection is not located there.

In embodiments, the connection between each spring rod and a strap is positioned in the upper half of the strap and in the rear half of the strap.

With these arrangements, each spring rod is above or behind the user's collarbones, eliminating the risk of hindering their arm movements.

In embodiments, the connection between each spring rod and the chest harness comprises a ball joint. This ball joint may consist of two pivot connections of different axes, or even of flexibilities of the mechanical parts implemented for this connection, for example in textile. The user is thus not hindered when leaning forward or backward because the ball joint absorbs the inclination of the thorax relative to the user's pelvis.

In embodiments, the connection between each spring rod and the abdominal belt is positioned against a hip of the user.

The forces exerted by the spring rods are thus applied at the user's hips and therefore do not tend to lean them forward or backward.

In embodiments, the connection between each spring rod and the abdominal belt is a ball joint connection.

Thanks to these arrangements, the user's pelvic movements are freer.

In embodiments, the exoskeleton includes a rigid or elastic connection between the central portions of the spring rods.

Thanks to these provisions, the spring rods are tightened towards the user's back in their middle part. This reduces the bulk of the exoskeleton at the user's back, or even allows the user to wear rain protection clothing over the exoskeleton.

In embodiments, the connections of each spring rod with the abdominal belt and with the chest harness are removable.

With these arrangements, the spring rods can be replaced, for example to adapt the exoskeleton to a user of a different size and/or to modify the force exerted by the spring rods which tends to move the user's thorax away from the user's abdomen.

In embodiments, each spring rod comprises a composite material and has, at rest, a cylindrical shape.

According to a second aspect, the present invention relates to a kit comprising an exoskeleton which is the subject of the invention and at least two sets of spring rods having different lengths and/or stiffnesses.

With these provisions, by changing the set of spring rods of the exoskeleton, it is adapted to a user of different morphology and/or the force exerted by the spring rods is adapted for the same user morphology. The user can thus choose the set of spring rods that corresponds to his morphology, in particular to the size of his torso and to the assistance he wishes to receive from the exoskeleton, in terms of force tending to move his thorax away from his abdomen.

Brief description of the figures

Other advantages, aims and particular characteristics of the invention will emerge from the non-limiting description which follows of at least one particular embodiment of the exoskeleton which is the subject of the present invention, with reference to the appended drawings, in which:

represents, in a schematic side view, a first particular embodiment of the exoskeleton which is the subject of the invention, worn by a user of predetermined morphology,

represents, in a back view, a second embodiment of the exoskeleton which is the subject of the invention,

represents, in back perspective, the exoskeleton illustrated in ,

represents an enlargement of a first part of the , comprising a connection between a spring rod and a strap,

represents an enlargement of a second part of the , comprising a connection between a shoulder strap and a chest harness, and

represents an enlargement of a third part of the , comprising a connection between a spring rod and an abdominal belt.

This description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous manner.

Throughout the description, the term “upper” or “top” refers to that which is at the top when a user wears the exoskeleton that is the subject of the invention and in the figures, and the term “lower” or “bottom” refers to that which is at the bottom when a user wears the exoskeleton that is the subject of the invention and in these figures. The figures thus represent the normal orientation of the exoskeleton during use by a standing or seated user. The “heights” follow from these definitions. The “widths” are defined from right to left in figures 2 to 6, therefore also from right to left of the user’s body. These are the dimensions in the direction from one shoulder to the other of the user. The term “front”, “in front”, “face” or “ventral” refers to that which is on the side of the user’s stomach during use of the exoskeleton and “rear” or “dorsal” refers to that which is on the side of the user’s back during use of the exoskeleton. We call "internal" or "interior" what is close to or turned towards the user's trunk and "external" or "exterior" what is far from this trunk or is turned towards what is far from this trunk.

It should be noted, from now on, that Figures 2 to 6 are to scale and adapted to an average European man, as defined by statistical studies of this population.

The exoskeleton that is the subject of the invention aims to combat back pain and improve working conditions by reducing the difficulty of remaining in a standing or sitting position and its physical and mental consequences on the user.

This exoskeleton is lightweight, intuitive to use and designed to relieve the spine of some of the load on the thorax and upper limbs. It is particularly suitable for all work requiring the carrying of loads with the arms. The user thus retains great freedom of movement. He is not hindered in the performance of tasks that do not require mechanical assistance.

The assistance, that is to say the mass directly supported by the exoskeleton between the thorax and the pelvis of the user without passing through his spine can reach 10 kg, or even 15 kg, 20 kg or more. The mass of the exoskeleton represented in the figures can be of the order of one kilogram. The inventors have observed a time of putting on the exoskeleton of less than two minutes and a time of removing the exoskeleton of approximately one minute.

An exoskeleton object of the invention is defined for a model user, for example a user with a height of 1.78 m and a mass of 77 kg.

Of course, the same exoskeleton may be suitable for a set of users whose characteristics are close to those of the model. The person skilled in the art responsible for producing an exoskeleton that is the subject of the invention knows, from the predetermined user for whom the exoskeleton is intended, how to determine the dimensions of his body, and in particular those of his trunk and limbs. Indeed, these anthropometric data are well documented. A trunk and an arm of a male model user are represented in , in broken lines.

The implementation of the invention therefore involves the production of a range of exoskeletons covering a large part of the users' morphologies, for example a single exoskeleton to cover the morphologies of 70% of the European population, two exoskeletons to cover 90% of the European population.

We observe, in , a particular embodiment 10 of the exoskeleton object of the invention. This exoskeleton 10 is worn by a user 11 (partially schematized in broken lines in ) whose morphology corresponds to that of one of the predetermined model users. This exoskeleton 10 comprises an abdominal belt 12 configured to surround the pelvis of this user 11 and a pectoral harness 13 configured to surround the thorax of the user 11.

The exoskeleton 10 also comprises, for each shoulder of the user, at least one spring rod 15 working in buckling and/or bending.

Each spring rod 15 is connected:
- at a first end, upper, to the pectoral harness 13 and
- at a second end, lower, to the abdominal belt 12.

The spring rod 15 has a length configured such that, when the user 11 wears the exoskeleton 10, the spring rod 15 takes the shape of an arc, as illustrated in , this shape passing behind the back of the user 11 and exerting a restoring force tending to lift the thorax of the user 11 and to move it away from his abdomen.

In the embodiment schematized in , the chest harness 13 comprises, for each shoulder of the user, a strap 14 configured to surround this shoulder.

In other embodiments (not shown), the chest harness 13 does not include a strap, each connection between the spring rod 15 and the chest harness 13 is therefore made below the shoulder, for example at the level of an armpit of the user.

In the embodiment schematized in , the connection 17 between the spring rod 15 and the strap 14 comprises a housing in which the upper end of the spring rod 15 is fitted and a pivot connection 9 connecting this housing to the strap 14. In the preferred embodiments illustrated in the figures, the spring rods 15 have a length greater than the distance between the hips and the collarbones of the user, this length being preferably at least 20% greater than this distance.

In the embodiment schematized in , the connection 16 between the spring rod 15 and the abdominal belt 12 is a pivot connection or a ball joint connection.

As is easily understood in view of the , the part of the spine (not shown) of the user 11 between the abdominal belt 12 and the chest harness 13, is relieved, by means of the spring rods 15, of part of the weight of the thorax and upper limbs of the user. Spinal pain and pain due to lower back pain can thus be reduced.

In the first embodiment illustrated in , the connection 17 between each spring rod 15 and a strap 14 is positioned above this strap 14, that is to say in a position further from the abdominal belt 12 than the strap 14 is.

Figures 2 to 6 show a second embodiment of an exoskeleton 20 that is the subject of the invention. In these figures, the references ending in “D” relate to the right part of the exoskeleton 20, which is located on the right half of the body of the user wearing this exoskeleton. The references ending in “G” relate to the left part of the exoskeleton.

This exoskeleton 20 comprises an abdominal belt 12 configured to surround the pelvis of this user and a pectoral harness 13D and 13G configured to surround the thorax of the user.

The abdominal belt 12 comprises a central back support 21 which also serves as a loop for the abdominal belt 12 and an extension 23 (on the right in FIGS. 2 and 3) made of self-gripping fabric, for example velvet, provided with an end 24 made of self-gripping fabric configured to grip onto the self-gripping fabric 23. The abdominal belt 12 comprises, at its opposite end (on the left in FIGS. 2 and 3), a loop 22 for the extension 23. To adjust the waist size, the user passes the extension 23 through the loop 22, pulls on this extension and folds it back on itself so that the self-gripping fabrics 23 and 24 attach. Self-gripping fabrics (not shown) are provided, in addition, at the level of the central back support 21, in order to adapt the waist size to a greater variety of morphologies and so that the connections 16D and 16G are located precisely on the user's hips. The connection 16D and 16G between each spring rod 15D and 15G and the abdominal belt 12 is thus positioned against a hip of the user.

A clip fastener 36 makes it possible to detach the loop 22 from the left part of the abdominal belt 12. Once the user has adjusted his waist size using the loops 21 and 22, he can simply use the clip fastener 36 to put on or remove the abdominal belt 12.

The abdominal belt 12 is provided with two links 16D and 16G with two spring rods 15D and 15G. As illustrated in , the connection 16D comprises, fitted at the lower end of the spring rod 15, a housing secured to a spherical part 31D. This spherical part 31D is retained in a housing 30D in the form of a drawer housing, the housing of which the upper opening allows the spherical part 31D to be disengaged. The connection 16D is thus a removable ball joint connection, i.e. removable by hand without tools. Alternatively, the spherical part 31D is replaced by a cylindrical part which provides a pivot connection, the pivoting taking place in the plane tangent to the abdominal belt 12.

The chest harness consists of two symmetrical parts 13D and 13G, connected, at the user's back, by a loop 25 on which the rear ends 27D and 27G (in the center in FIGS. 2 and 3) of the parts 13D and 13G are attached independently. The front ends 26D and 26G of the parts 13D and 13G also have self-gripping fabrics allowing them to be attached to each other in front of the user's chest. Between the ends, respectively 26D and 27D, on the one hand, and 26G and 27G, on the other hand, the parts 13D and 13G are flexible, for example made of textile. 28D and 28G frames, more rigid than these flexible parts, are positioned to be located under the user's armpits and to constitute the rear part of the 14D and 14G shoulder straps, at the level of the user's shoulder blades. The frames, for example in HDPE (acronym for High Density Polyethylene), extend to the 17D and 17G connections of the 15D and 15G spring rods. The remainder of the 14D and 14G shoulder straps is made of flexible material, for example textile, and is connected to the 28D and 28G frame by a loop fastener 37 (see ) and hook-and-loop fabric, as previously described for loop 22. As illustrated in , a 33D yoke, removable by hand, terminates the upper end of the 15D spring rod. This 33D yoke has a cylindrical head inserted into a 34D housing, with which it forms a pivot connection with an axis perpendicular to the 28D frame. The 33D yoke comprises two parts mounted on a pivot connection with an axis perpendicular to the upper end of the 15D spring rod. The 17D and 17G connection between each 15D and 15G spring rod and a 14D and 14G strap thus comprises a ball joint connection consisting of a succession of two pivot connections with perpendicular axes. This ball joint connection may consist of two pivot connections with different axes, or even of flexural flexibility of the mechanical parts used for this connection, for example in textile. Alternatively, the connection between the upper end of each 15D and 15G spring rod and a 14D and 14G strap is a pivot connection.

The 34D housing is movable on the 28D frame and can be locked on this 28D frame after movement. This movement allows the flexion of the 15D spring rod to be adjusted with the left hand, over the right shoulder.

An adjustment is made to prevent shearing at the left armpit, as shown in . Again, a 32G loop and a self-gripping fabric are implemented to ensure the comfort of the user. This 32G loop can be moved between several positions, by means of a lug ending in a spherical head inserted into a 38G through opening of the 28G frame (three 38G openings are shown in ).

A rigid or elastic link, for example a strap, 35 connects the central parts of the spring rods 15D and 15G. This link 35 makes it possible to limit the bulk of the exoskeleton 20 at the back of the user by folding the central parts of the spring rods 15D and 15C towards the center of the back.

The 15D and 15G spring rods are, as explained above, removable without tools. They can thus be changed, for example when the user wishes to increase the stiffness of the 15D and 15G spring rods in order to increase the force exerted by these 15D and 15G spring rods to relieve his spine.

The exoskeleton 20 also includes, for each shoulder of the user:
- a 14D and 14G strap connected to the chest harness 13 and configured to surround this shoulder, and
- at least one 15D and 15G spring rod working in buckling and/or bending.

Each 15D and 15G spring rod is connected:
- at a first end, upper, to a 14D and 14G strap and
- at a second end, lower, to the abdominal belt 12.

Each 15D and 15G spring rod has a length configured such that when the user wears the exoskeleton 20, the 15D and 15G spring rod assumes the shape of an arc, as illustrated in , this shape passing behind the user's back and exerting a restoring force tending to lift the user's thorax and move it away from his abdomen.

In this second embodiment, too, the user's spine (not shown) is relieved of part of the weight of the user's thorax and upper limbs by means of the spring rods 15D and 15G. Spinal pain and pain due to lower back pain are thus reduced.

Preferably, the chest harness is configured to surround the user's thorax below the xiphoid process.

In the second embodiment illustrated in Figures 2 to 6, the connection 17D and 17G between each spring rod 15D and 15G and a strap 14D and 14G is positioned in the upper half of the strap 14D and 14G and in the rear half of the strap 14D and 14G. This quarter is represented by perpendicular broken lines, in Figures 1 and 2, for each strap 14, 14D and 14G.

Preferably, each 15D and 15G spring rod comprises a composite material and has, at rest, a cylindrical shape.

In embodiments (not shown), the spring rods are, at rest, that is to say in the absence of forces exerted on them, straight rods.

Preferably, a kit comprising the exoskeleton which is the subject of the invention comprises a plurality of sets of 15D and 15G spring rods having different lengths and/or stiffnesses.

For example, four spring rod stiffnesses are used to meet a wide range of user demands, pain conditions or pathologies:
- 200 Newtons per pair,
- 110 Newtons per pair,
- 80 Newtons per pair, and
- 40 Newtons per pair.

For example, the lengths of the 15D and 15G spring rods of the different sets are in the range of 550 mm to 850 mm.

The applicant has discovered that, due to the arc shape of a straight spring rod at rest, the restoring forces exerted by the spring rods on the belt, on the one hand, and on the chest harness, on the other hand, parallel to the chord of this arc, are substantially constant during the deformation of the spring rods.

Note that the spring rods put in place by the user can be different for the two shoulders, for example to relieve pain linked to scoliosis or another back deformity.

In embodiments, the chest harness includes an extension to at least partially surround the user's neck. These embodiments provide relief from neck pain.

Further information on embodiments of the invention is given below.

The exoskeleton object of the invention has at least two gripping zones of the spine to stretch it. These two zones are as far apart as possible to stretch a larger segment of the spine. In embodiments, these zones are materialized by:
- a belt on the user's hips,
- a high belt at the level of the lower ribs, higher ribs and/or cervical vertebrae.

In embodiments, the number of spring rods is greater than two, for example four. For example, with four spring rods, two cross over the user's back, with the other two remaining on the same side of the user's body as described with respect to the figures.

The exoskeleton which is the subject of the invention is particularly suitable for workstations requiring prolonged standing or sitting, in particular on a seat without a backrest, with repetitive handling of objects involving movements of the dorso-lumbar area of the spine.

These risky postures cause fatigue and back pain in many sectors and professions (non-exhaustive lists):
- industry,
- distribution and trade,
- health, and
- agri-food.

The exoskeleton that is the subject of the invention is intended in particular for cable layers, electricians, sorting operators, laboratory technicians, clothing workers, welders, health professions, and dairy milking, for example.

Claims (11)

Exoskeleton (10, 20) for a user (11) of predetermined morphology, comprising an abdominal belt (12) configured to surround the pelvis of this user, a pectoral harness (13, 13D, 13G), characterized in that it further comprises, for each shoulder of the user at least one spring rod (15, 15D, 15G) working in buckling and/or flexion, each spring rod being connected:
- at a first end, to this pectoral harness, and
- at a second end, at the abdominal belt;
the spring rod having a length configured such that, when the user wears the exoskeleton, the spring rod takes the shape of an arc passing behind the user's back and exerts a restoring force tending to lift the user's thorax and away from his abdomen. Exoskeleton (10, 20) according to claim 1, in which at least one spring rod (15, 15D, 15G) is, at rest, a straight rod. Exoskeleton (10, 20) according to one of claims 1 or 2, in which the chest harness (13, 13D, 13G) comprises, for each shoulder of the user, a strap (14, 14D, 14G) configured to surround this shoulder, the connection between each spring rod (15, 15D, 15G) and a strap being positioned above this strap, that is to say in a position further from the abdominal belt (12) than the strap is. The exoskeleton (10, 20) of claim 3, wherein the connection (17, 17D, 17G) between each spring rod (15, 15D, 15G) and a shoulder strap (14, 14D, 14G) is positioned in the upper half of the shoulder strap and in the rear half of the shoulder strap. Exoskeleton (10, 20) according to one of claims 1 to 4, in which the connection (17, 17D, 17G) between each spring rod (15, 15D, 15G) and the pectoral harness (13, 13D, 13G) comprises a ball joint connection. Exoskeleton (10, 20) according to one of claims 1 to 5, in which the connection (16, 16D, 16G) between each spring rod (15, 15D, 15G) and the abdominal belt (12) is positioned against a hip of the user (11). Exoskeleton (10, 20) according to one of claims 1 to 6, in which the connection (16, 16D, 16G) between each spring rod (15, 15D, 15G) and the abdominal belt (12) is a ball joint connection. Exoskeleton (20) according to one of claims 1 to 7, which comprises a rigid or elastic link (35) between the central parts of the spring rods (15D, 15G). Exoskeleton (10, 20) according to one of claims 1 to 8, in which the connections (16, 17, 16D, 17D, 16G, 17G) of each spring rod (15, 15D, 15G) with the abdominal belt (12) and with the pectoral harness (13, 13D, 13G) are removable. Exoskeleton (10, 20) according to one of claims 1 to 9, in which each spring rod (15, 15D, 15G) comprises a composite material and has, at rest, a cylindrical shape. Kit comprising an exoskeleton (10, 20) according to one of claims 1 to 10 and at least two sets of spring rods (15, 15D, 15G) having different lengths and/or stiffnesses.