Exoskeleton allowing a wide range of shoulder movement

Abstract

An exoskeleton comprising: a dorsal structure (10) connected to an arm structure (30) by a scapular structure (20) having a shoulder actuator (24) for moving the arm structure relative to the dorsal structure. The scapular structure includes a first joint (21) fixed to an upper portion (11) of the dorsal structure (10), and a carriage (23) connected to a portion of the first joint (21) for sliding relative to the first joint (21) in a direction substantially perpendicular to the first joint axis (A1). The shoulder actuator (24) is mounted on the carriage (23) by a second joint (25) having a second joint axis (A2) substantially parallel to the first joint axis (A1). The exoskeleton includes a first elastic element (27) for returning the carriage to a predetermined resting position and a second elastic element (28) for returning the carriage (23) to the first joint (21).SUMMARY FIGURE : Fig. 1.

Description

Title of the invention: Exoskeleton allowing a wide range of shoulder movement

[0001] The present invention relates to the field of devices equipped with a motor or assistance and worn by the human body to improve its capabilities, and in particular exoskeletons.

[0002] BACKGROUND OF THE INVENTION

[0003] Exoskeletons comprising the following are known from documents FR-A-3046052 and FR-A-3072598: a dorsal structure having an upper portion designed to extend to the height of a user's shoulder blades, an arm structure provided with means for its attachment to one of the user's arms, and a scapular structure connecting the arm structure to the upper portion of the dorsal structure. The scapular structure includes a shoulder actuator for moving the arm structure relative to the dorsal structure.

[0004] Now, the shoulder is a complex joint system allowing six degrees of freedom through the combination of movements of the shoulder joint itself and movements of the scapula.

[0005] This complexity allows a great freedom of movement of the arms, with abduction / adduction, elevation / lowering, and rotation movements.

[0006] Ideally, in most applications, the exoskeleton should not hinder arm movements while keeping the shoulder actuator close to the shoulder joint.

[0007] In practice, the exoskeleton may prove to be awkward for extreme arm movements, such as when the user wants to touch one of his shoulders with the opposite hand or spread his arms as far apart as possible by bringing his shoulder blades together.

[0008] SUBJECT OF THE INVENTION

[0009] The invention aims in particular to provide an exoskeleton architecture limiting the aforementioned disadvantages. Summary of the invention

[0010] To this end, the invention provides an exoskeleton comprising: a dorsal structure having an upper part designed to extend to the height of the user's shoulder blades, at least one brachial structure provided with means for its attachment to one of the user's arms, and a scapular structure connecting the brachial structure to the upper part of the dorsal structure and including a shoulder actuator for moving the brachial structure relative to the dorsal structure. The scapular structure includes at least one first joint attached to the upper part of the dorsal structure. To have a first axis of articulation substantially parallel to a local spinal axis, a carriage is connected to a portion of the first joint to slide relative to the first joint in a direction substantially perpendicular to the first axis of articulation and intended to be parallel to the scapulae during use of the exoskeleton. The shoulder actuator is mounted on the carriage by a second joint having a second axis of articulation substantially parallel to the first axis of articulation. The exoskeleton includes a first elastic element for returning the carriage to a predetermined resting position and a second elastic element for returning the carriage to the first joint.

[0011] Thus, the combination of movements of the first joint and the sliding carriage frees the scapula by allowing a wide variety of movements and in particular large amplitude movements such as when the arms are widely spread apart, a movement allowed by bringing the scapulae closer together, or on the contrary when the arms are crossed on the torso, each hand grasping the opposite shoulder, a movement allowed by moving the scapulae apart.

[0012] Other features and advantages of the invention will become apparent from the following description of a particular, non-limiting embodiment of the invention. Brief description of the drawings

[0013] Reference will be made to the attached drawings, among which:

[0014] [Fig-1] [Fig.1] is a rear view of the exoskeleton according to the invention;

[0015] [Fig.2] [Fig.2] is a three-quarter rear view of the exoskeleton according to the invention;

[0016] [Fig.3] [Fig.3] is a side view of the exoskeleton according to the invention;

[0017] [Fig.4] [Fig.4] is a front view of the exoskeleton according to the invention;

[0018] [Fig.5] [Fig.5] is a detailed view of the first joint located in area V of [Fig.2];

[0019] [Fig.6] [Fig.6] is a partial side view of the upper part of the brachial structure of the exoskeleton according to the invention;

[0020] [Fig.7] [Fig.7] is a partial perspective view of the lower part of the brachial structure of the exoskeleton according to the invention;

[0021] [Fig.8] [Fig.8] is a top view of the exoskeleton with the right brachial structure in maximum extension towards the rear and the left brachial structure along the user's body;

[0022] [Fig.9] [Fig.9] is a detail view of area IX of [Fig.8];

[0023] [Fig. 10] [Fig. 10] is a top view of the right scapular structure for a position of the brachial structure along the user's body;

[0024] [Fig. 11] [Fig. 11] is a detailed perspective view of the means for recalling the trolley and the lower part of the dorsal structure of the exoskeleton according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] With reference to the figures, the exoskeleton according to the invention, bearing the general reference 1, comprises a dorsal structure, generally designated as 10, which is intended to extend along the back of a user and which is connected by two scapular structures (or shoulder structures), generally designated as 20, to two brachial structures, generally designated as 30.

[0026] The dorsal structure 10 comprises a T-shaped plate and has an upper part 11 (the T-bar) intended to extend to the height of a user's shoulder blades and a lower part 12 (the T-leg) connected to a ventral belt 40 by a length-adjustable connecting plate 41 to allow height adjustment of the dorsal structure 10 relative to the ventral belt 40. The connecting plate 41 comprises an inverted T-shaped plate 411, integral with the ventral belt 40 and provided with two oblong longitudinal slots 412, and a plate 413 which is at least partially covered by the plate 411 and which is integral with the lower part 12. The plate 413 is a single piece with the lower part 12 and has two protruding eccentric locks 414.Each eccentric lock 414 comprises a rod received in one of said slots 412 and a head movable on the rod by means of an eccentric lever between a tightened position in which the head bears against the plate 411 to press it against the plate 413 so as to secure the plates 411,413 to each other by friction and a loosened position in which the head is free from the plate 411 and allows the plate 411 to slide on the plate 413.

[0027] The scapular structures 20 are identical to each other and each connects one of the brachial structures 30 to the upper part 11 of the dorsal structure 10.

[0028] Each scapular structure 20 comprises at least one first joint 21 having bearings 211 fixed to the upper part 11 of the dorsal structure 10 and a shaft 212 whose ends are received pivotally in the bearings 211 to constitute a first joint axis A1 substantially parallel to a local spinal axis, that is to say the general axis of the vertebrae located between the shoulder blades, namely an axis inclined 20° forwards with respect to the vertical when the user is standing. In practice, since the plate forming the dorsal structure 10 is shaped to extend along the user's spine, the first articulation axis Al extends from bottom to top substantially parallel to the upper part 12. From the shaft 212 extend two rails 22, perpendicular to the articulation axis Al, on which a carriage 23 carrying a shoulder actuator is mounted to slide. 24 of the motor shaft M1. The two rails 22 have their ends opposite the shaft 212 connected to each other by a bar 221 forming a stop to the sliding of the carriage 23. The carriage 23 is, for example, equipped with plain or ball bearings to facilitate its sliding on the rails 22. The carriage 23 can thus slide on the rails 22 in a direction substantially perpendicular to the first articulation axis A1 and parallel to the user's shoulder blades. The stroke of the carriage 23 is, for example, 60 mm, which can be modified by changing the rails 22.The shoulder actuator 24 is connected to the carriage 23 by a second joint 25 comprising bearings 251 attached to a flange 26 and a shaft 252 which is attached to an extension of the carriage 23 and which has ends received in the bearings 251 to constitute a second joint axis A2 substantially parallel to the first joint axis Al allowing an angular travel of about 65° of the actuator with respect to the carriage 23. The flange 26 rigidly connects a housing of the shoulder actuator 24 to the bearings 251.

[0029] The scapular structure 20 includes a first elastic element 27 for returning the first joint 21, and therefore the rails 22, to a predetermined neutral or rest position (which corresponds substantially to a rest position of the user standing with arms along the body) and a second elastic element 28 for returning the carriage 23 to the first joint 21.

[0030] The first elastic element 27 comprises two opposing torsion springs 271, 272 mounted between the shaft 212 and each of the bearings 211 to return the shaft 212 to a neutral or rest position between two extreme positions corresponding to a forward displacement of the distal part of the scapula (the arm passes in front of the torso and the hand grasps the opposite shoulder) and a backward displacement of the distal part of the scapula (the arms are fully extended, see the right scapular structure in [Fig. 8]). In the neutral position, the carriage 23 is preferably located near the upper part 11 and the rails extend parallel to a frontal plane of the user (see the left scapular structure in [Fig. 8]). In the first extreme position, the rails 22 make an angle of 5° forward with said plane and, in the second extreme position, the rails 22 make an angle of 20° backward with said plane.

[0031] The second elastic element 28 comprises an extendable tension spring 281 extending along the lower part 12 of the dorsal structure 10 substantially in a local spinal direction (i.e., substantially vertically when the user is standing) and having one end fixed to the lower part 12 and an opposite end connected to one end of a cable 282 having an opposite end connected to the carriage 23. The cable 282 passes through a bore formed in a portion of the first joint 21 rotationally connected with the carriage 23, namely the shaft 212, such that the section of cable extending between the carriage 23 and the first joint culation 21 is always parallel to the rails 22 and does not exert a rotational torque on the shaft 212 and the carriage 23. Cable guide eyelets 282 are fixed on the back structure 10 between the first articulation 21 and the spring 281 to hold the cable 282 along the back structure 10 without hindering its longitudinal movement due to the movements of the user and the return exerted by the spring 281 on the carriage 23.

[0032] The shoulder actuator 24 has an output shaft provided with a lever 241 connected by a third joint 31 to a first end of an arm segment 32 of the brachial structure 30. The third joint 31 comprises bearings 311 integral with the lever 241 and a shaft 312 having ends engaged in the bearings 311 to form a third joint axis A3 substantially perpendicular to a longitudinal axis of the arm segment 32 and to a drive axis of the shoulder actuator 24. The arm segment 32 has a second end connected to an elbow actuator 33 with drive axis M2 by a fourth joint 34. The fourth joint 34 comprises two bearings 341 integral with a connecting plate 35 and a shaft to which the second end of the arm segment 32 is integral and which has two ends engaged in the bearings 341 to form a fourth axis articulation A4 substantially perpendicular to the longitudinal axis of arm segment 32.The fourth articulation axis A4 is angularly offset relative to the motor axis M2 of the elbow actuator 33. The offset here is 35°. The third articulation axis A3 is angularly offset relative to the fourth articulation axis A4. The arm segment 32 extends rearward relative to the actuator 33.

[0033] The arm segment 32 has a variable length and is elastically returned to a shorter length by a third elastic element 36. The arm segment 32 comprises a sleeve 321 which receives a rod 322 by sliding and pivoting: the sleeve 321 forms the first end of the arm segment 32 and the rod 322 forms the second end of the arm segment 32. The third elastic element 36 comprises two tension springs 361, 362, one end of which is fixed to the sleeve 321 near the third joint 31 and the other end of which is fixed to the rod 322 near the fourth joint 34. These springs serve both to retract the rod 322 into the sleeve 321 and to return it to a predetermined neutral angular position relative to the sleeve 322. The telescopic nature of the arm segment 32 allows it to adapt to both the user morphology and movements.

[0034] The connecting plate 35 is adjustable in length and comprises an interface 351 for contact with the user's arm, carrying the bearings 341, and a flange 352 having one end integral with a housing for the elbow actuator 33 and one end provided with a longitudinal slot 353, oblong in shape, which slidably receives a tenon of the interface 351. A lever lock 354 is engaged in the tenon of the interface 351 and has its rod received in the longitudinal slot 353 and its head resting against the flange 352 to immobilize the interface 351 in position along the flange 352. The interface 351 in contact with the user's arm is arranged between the elbow actuator 33 and the fourth joint 34.

[0035] The elbow actuator 33 has an output shaft to which is attached a lever 331 connected to a forearm segment 37 by a fifth joint 38 comprising bearings 381 attached to the lever 331 and a shaft 382 having ends engaged in the bearings 381 to constitute a fifth joint axis A5 substantially perpendicular to a longitudinal direction of the forearm segment 37 and to the motor axis M2.

[0036] The elbow actuator 33 is thus connected to the fourth joint A4 by a first connecting plate 35 adjustable in length.

[0037] The forearm segment 37 comprises a proximal interface 371 for contact with the user's forearm near the elbow and a distal interface 372 for contact with the user's forearm near the wrist. The forearm segment 37 comprises an adjustment member along the forearm segment 37 for at least one of the proximal interfaces 371 and 372. The proximal interface 371 is integral with the shaft 382 and is provided, opposite it, with a plate 3711 mounted to slide on the distal interface 372 and having a longitudinal slot 3712. A lever lock 373 is engaged in the proximal interface 372 and has its stem received in the longitudinal slot 3712 and its head supported. against the plate 3711 to immobilize the proximal interface 372 in position along the plate 3711.

[0038] Stops are provided to limit certain movements, such as the bar 221 limiting the sliding of the carriage 23. Among these stops, there is also the surface 232 of the carriage 23 which comes into contact with the surface 242 of the shoulder actuator 24 when the arm is in maximum extension to the rear (see the right scapular structure in [Fig. 8] and in [Fig. 9]) and the surface 233 of the carriage 23 which comes into contact with the surface 244 of the flange 26 of the shoulder actuator 24 when the arm is brought in front of the torso and the hand grasps the opposite shoulder. When the surface 232 of the carriage 23 is in contact with the surface 242 of the shoulder actuator 24, the flange 26 carrying the shoulder actuator forms an angle of approximately 160° (counter-clockwise in [Fig. 8]).9]) with the guidance direction of the carriage 23 (i.e. with the longitudinal direction of the rails 22): the motor shaft Ml which extends at 90° with respect to the flange 26 forms an angle of approximately 65° (trigonometric direction on [Fig.9]) with the guidance direction of the carriage 23. When the surface 233 of the carriage 23 is in contact with the surface 243 of the shoulder actuator 24, the flange 26 carrying the shoulder actuator forms an angle of approximately 225° (trigonometric direction on [Fig.9]) with the . carriage guidance direction 23 (i.e. with the longitudinal direction of the rails 22): the motor shaft M1 forms an angle of approximately 135° (trigonometric direction on [Fig.9]) with the carriage guidance direction 23.

[0039] Similarly, it is also possible to provide stops to limit the pivoting of joints 31, 34 and 38.

[0040] The dorsal structure 10, the ventral belt 40, and the contact interfaces 351, 371, 372 are equipped with pads to rest against the user's body without risk of injury. The ventral belt 40 and the contact interfaces 351, 371, 372 are each further equipped with a strap to encircle the part of the user's body against which it rests. This strap may be equipped with hook-and-loop fasteners or a tightening buckle. These straps constitute means of attaching the various structures to the user's body.

[0041] It should be noted that the sliding motion of the carriage 23 allows it to adapt to the user's body shape and to follow their movements. Preferably, the rails 22 are attached to the shaft 212 in a removable manner so that the rails 22 can be replaced by longer rails for use by a user with a very broad build. Indeed, the carriage 23 must ensure that the shoulder actuator is always located near the shoulder joint. More precisely, the carriage 23 allows the projection of the motor axis M1 to be aligned with the center of the user's humeral head or with the junction between the humerus and the scapula, which corresponds to the center of rotation of the joint.

[0042] It is understood that the plates 41, 35 and 3711 allow the exoskeleton to be adapted to the morphology of the user.

[0043] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0044] In particular, the exoskeleton may have a different structure from that shown.

[0045] The first joint may comprise only one spring. The first organ The elastic element may have a different structure than that described. The opposing torsion springs of the first elastic element may be replaced by spiral springs or compression or extension springs mounted between lugs.

[0046] The second elastic return element of the carriage may have a different structure and, for example, include springs mounted directly between the carriage and the first joint, i.e., a cable-free assembly.

[0047] The third elastic return member may have a different structure from that described and include a separate tension spring and a separate tension spring.

[0048] The arm segment may have a different structure from that described and for example The arm segment may lack a rod inserted into a sleeve and comprise, for example, two rods extending side by side and connected to each other by a slide. Rather than a pivot-sliding joint between the rod and its sleeve, a simple sliding joint may be used. The arm segment may then lack a pivot around its longitudinal axis or, conversely, include a pivot joint at the end of the rod and / or the sleeve.

[0049] The exoskeleton may be devoid of an elbow actuator and forearm segment.

[0050] The means for adjusting the height of the back structure relative to the belt lobar may differ from those described and include, for example, a wheel mounted to pivot on the lumbar belt and provided with an off-center pin engaged in a horizontal groove of the dorsal structure.

[0051] By "substantially parallel" is meant that the axes are parallel to each other to within a maximum of five degrees. The same applies to "substantially perpendicular".

[0052] The actuators may incorporate electric motors or torsion springs.

[0053] Lever locks can be replaced by screws or a ratchet and notch system. Adjustable length plates are optional when the exoskeleton is custom-made for a user.

Claims

Demands

1. Exoskeleton comprising: a dorsal structure (10) having an upper part (11) intended to extend to the height of the user's shoulder blades, at least one brachial structure (30) provided with means for its attachment to an arm of the user, and a scapular structure (20) connecting the brachial structure to the upper part of the dorsal structure and comprising a shoulder actuator (24) for moving the brachial structure relative to the dorsal structure, characterized in that the scapular structure comprises at least one first joint (21) fixed to the upper part (11) of the dorsal structure (10) so as to have a first joint axis (A1) substantially parallel to a local spinal axis,a carriage (23) connected to a part of the first joint (21) to slide relative to the first joint (21) in a direction substantially perpendicular to the first joint axis (A1) and intended to be parallel to the scapulae during use of the exoskeleton, the shoulder actuator (24) being mounted on the carriage (23) by a second joint (25) having a second joint axis (A2) substantially parallel to the first joint axis (A1), and in that the exoskeleton comprises a first elastic element (27) for returning the first joint to a predetermined rest position and a second elastic element (28) for returning the carriage (23) to the first joint (21).

2. Exoskeleton according to claim 1, wherein the first elastic member (27) comprises two antagonistic torsion springs (271, 272).

3. Exoskeleton according to any one of the preceding claims, wherein the second elastic member (28) comprises a tension spring (281) extending substantially in a local spinal direction and having one end fixed to the dorsal structure (10) and an opposite end connected to one end of a cable (282) having an opposite end connected to the carriage (23).

4. Exoskeleton according to claim 3, wherein the cable (282) passes through a bore formed in a part (212) of the first joint (21) connected in rotation with the carriage (23).

5. Exoskeleton according to claim 1, wherein the brachial structure (30) comprises an elbow actuator (33) connected to the shoulder actuator (24) by an arm segment (32) which has a variable length and which is elastically brought back into a shorter length state by a third elastic organ (36).

6. Exoskeleton according to claim 5, wherein the arm segment (32) comprises a sheath (321) slidingly receiving a rod (322).

7. Exoskeleton according to claim 6, wherein the sheath (321) receives the rod (322) also pivoting.

8. Exoskeleton according to claim 7, wherein the third elastic member (36) is extensible and has one end attached to the sheath (321) and one end attached to the rod (322) to both retract the rod (322) into the sheath and recall it to a predetermined angular position relative to the sheath (321).

9. Exoskeleton according to any one of claims 5 to 8, wherein the arm segment (32) has a first end connected to the shoulder actuator (24) by a third joint (31) having a third joint axis (A3) substantially perpendicular to a longitudinal axis of the arm segment (32) and to a motor axis (M1) of the shoulder actuator (24) and a second end connected to the elbow actuator (33) by a fourth joint (34) having a fourth joint axis (A4) substantially perpendicular to a longitudinal axis of the arm segment (32) and to a motor axis (M2) of the elbow actuator (33).

10. Exoskeleton according to claim 9, wherein the third articulation axis (A3) is angularly offset with respect to the fourth articulation axis (A4).

11. Exoskeleton according to claim 9 or 10, wherein the elbow actuator (33) is connected to the fourth joint (A4) by a first connecting plate (35) adjustable in length.

12. Exoskeleton according to any one of claims 9 to 11, wherein the brachial structure (30) is provided with an interface (351) for contact with the user's arm, disposed between the elbow actuator (33) and the fourth joint (34).

13. Exoskeleton according to any one of claims 5 to 12, wherein the elbow actuator (33) is connected to a forearm segment (37) by a fifth joint (38) having a fifth joint axis (A5) substantially perpendicular to a longitudinal direction of the forearm segment (32) and to a drive axis (M2) of the elbow actuator (33).

14. Exoskeleton according to claim 13, wherein the forearm segment (37) is provided with a proximal interface (371) for contact with the user's body in the vicinity of his elbow and a distal interface (372) for contact with the user's body in the vicinity of his wrist, the forearm segment (37) includes a position adjustment member along the forearm segment (37) of at least one of the proximal interface (371) and the distal interface (372).

15. Exoskeleton according to any one of the preceding claims, comprising a ventral belt (40) connected to the dorsal structure (10) by a second connecting plate (41) adjustable in length to allow height adjustment of the dorsal structure (10) relative to the ventral belt (40).

Images