EP2938311B1

EP2938311B1 - A reciprocal device for gait learning assistance

Info

Publication number: EP2938311B1
Application number: EP13720909.4A
Authority: EP
Inventors: Grzegorz Kordyl
Original assignee: Liw Care Technology Sp Z Oo
Current assignee: Liw Care Technology Sp Z Oo
Priority date: 2013-05-01
Filing date: 2013-05-01
Publication date: 2016-03-09
Anticipated expiration: 2033-05-01
Also published as: EP2938311A1; WO2014177206A1; PL2938311T3

Description

TECHNICAL FIELD

The present invention relates to reciprocal devices for enabling the movement of lower extremities according to natural gait pattern.

BACKGROUND ART

It is well known that walking with a straight posture is essential for proper functioning of the body, i.e. for circulatory system, digestive system, muscular system etc. However, many temporarily or permanently disabled persons are not able to walk at all or without assistance of some kind - they need to be supported either by other persons or using specially designed equipment, and often both simultaneously. During such assisted walking the legs of the disabled person have to be specifically guided so as to imitate natural gait pattern. The person acting as an assistant has to be trained and physically able to efficiently help during such walking. On the other hand, the present equipment enabling the imitated gait for the disabled person is mostly of complicated structure, significant weight and, most importantly, high cost of purchase and maintenance.
A PCT application WO2012/049442 presents a device for enforcing the movement of lower limbs, characteristic for gait. It comprises a frame with several pairs of actuators, connected to the holding means for specific parts of legs. Such construction requires an algorithm for controlling the work of the actuators. It also involves high costs and probable problems with transportation due to the size and construction of the frame.
A US patent US7938756 presents a mobile apparatus for lifting, gait training and omnidirectional rolling. It can be used by persons with complete loss of walking abilities. The device comprises means for lifting and moving feet of a person, such as linear motion screw with nut, servomotor or timing belt. Furthermore, it necessitates advanced steering means. Combination of such features results in significant weight of the device, its complexity and costliness.
An European Patent application EP2193774 presents the walking auxiliary equipment. The construction requires several actuators, preferably in form of so-called Mc Kibben artificial muscles, which contract when supplied with compressed air. Such solution requires elements such as electropneumatic regulator or air canister, contributing to the cost and complexity of the device.
A US patent US2210269 describes a means to aid in regaining normal body and limb locomotion, comprising a mobile frame mounted upon wheels, a cam and lever means in cooperative connection with one of said wheels and operated therefrom by the motion of said wheel, an articulate brace means in operative connection with said cam and lever means and supported by said mobile frame member, according to the preamble of claim 1.
A PCT patent application WO01/14018A1 describes a robotic exoskeleton having two degree-of-freedom robot arms, wherein the first degree of freedom of the robot arms is rotational and the second (or subsequent) degree of freedom is linear of telescoping nature.
The aim of the present invention is to provide a mobile reciprocal device for enforcing the movement of the lower extremities in a manner resembling the pattern of the natural gait, while maintaining low costs of production and maintenance, accompanied with relatively low weight and dimensions of the device.

DISCLOSURE OF THE INVENTION

The object of the present invention is a mobile reciprocal device for enforcing the movement of lower extremities, comprising a mechanical linkage coupled with an orthosis for lower extremities and a drive for enforcing the movement of the linkage, wherein the linkage is coupled with the drive via a crank mechanism.
Preferably, the crank mechanism comprises a disc pivotally fixed with respect to the frame of the device and coupled with a guiding plate comprising a guiding slot coupled with a guiding bolt fixed with respect to the frame of the device.
Preferably, the guiding plate comprises a mounting portion for pivotally connecting with the disc and two mounting portions for pivotally connecting with the linkage, which comprises linkage bars.
Preferably, the orthosis is pivotally mounted in respect to the frame and comprises a thigh portion pivotally joined with a crus portion and wherein the linkage bar is connected to the thigh portion and the linkage bar is connected to the crus portion.
Preferably, the guiding slot of the guiding plate has a shape of a curved path.

BRIEF DESCRIPTION OF DRAWINGS

The present invention is shown by means of exemplary embodiments on a drawing, in which:

Fig. 1 shows a device in a front isometric view.
Fig. 2 shows the device in a rear isometric view.
Fig. 3 shows a leg unit in the left side view.
Fig. 4 shows a guiding plate in a left side view.
Fig. 5 shows leg units in front isometric view.
Fig. 6a - 6d shows the leg unit arrangement in four consequent positions according to the position of the disc.
Fig. 7 shows a support unit.
Fig. 8 shows a drive unit.

MODES FOR CARRYING OUT THE INVENTION

Fig. 1 shows a mobile reciprocal device according to the invention, in its exemplary embodiment, showed in a front isometric view. The device comprises following units: leg units 10, 20, a drive unit 30 and a support unit 50.
Fig. 2 shows the device in a rear isometric view.
Fig. 3 shows a leg unit 10, which comprises a linkage 1, an orthosis 2 and a crank mechanism 4. The orthosis 2 comprises a thigh portion 17 pivotally joined with a crus portion 16, which is in turn pivotally joined with a foot portion 18.
Fig. 4 shows a guiding plate 12 in a left side view, with its portions 12a, 12b, 12c and a guiding slot 12d. The guiding slot 12d is for guiding the plate 12 along a fixed guiding bolt 13, which in combination with forcing the movement of the plate 12 by a portion 11 a of a disc 11 guides the linkage in a precise, predetermined way. The track of the guiding slot 12d is a fragment of an arc, i.e. it forms a curved path, and allows only for a reciprocal motion of the guiding plate 12 and its rotation around the fixed bolt 13.
Fig. 5 shows leg units 10, 20 in the front isometric view. As stated above, the leg unit 10 comprises the linkage 1, the crank mechanism 4 and the orthosis 2. The crank mechanism 4 comprises a disc 11, mounted on a shaft coupled with the drive 3, and a guiding plate 12. The disc 11 is pivotally fixed with respect to the frame of the device (not shown for simplicity of the drawing) and coupled with a guiding plate 12 comprising a guiding slot 12d coupled with a guiding bolt 13 fixed with respect to the frame of the device. Therefore, the guiding bolt 13 is in a fixed relationship with respect to the centre of the disc 11. The disc 11 is connected to the guiding plate 12 by a joint, preferably by a pivot joint, in portion 11 a. The portion 11 a is situated near the periphery of the disc 11. Portion 11 a is connected to a portion 12a of the guiding plate 12, so that the guiding plate 12 can rotate around the portion 11 a with the axis of rotation intersecting said portion 12a. The device comprises also a fixed guiding bolt 13, positioned inside a guiding slot 12d of the movable guiding plate 12. The linkage 1 comprises two linkage bars 14, 15. The first end of the linkage bar 14 is coupled with the portion 12b of the guiding plate 12. The second end of the linkage bar 14 is coupled with a thigh portion 17 of the leg unit 10. The first end of the linkage 15 is coupled with the portion 12c of the guiding plate 12. The second end of the linkage bar 15 is coupled with a crus portion 16 of the leg unit 10. The connections between the linkage bars 14, 15 and guiding plate 12, as well as between the linkage bars 14, 15 and crus portion 16 and thigh portion 17 are preferably in form of spherical joints. The leg unit 10 further comprises a mounting portion 19, in which pivotally in point 17a is mounted the thigh portion 17. The thigh portion 17 is pivotally connected with a crus portion 16 in point 17b. The thigh portion 17 and the crus portion 16 correspond to a thigh and a crus of a person, and are aligned substantially next to them on the lateral side during a normal using. The crus portion 16 comprises the foot portion 18, as well as a holder 16h for attaching to the persons crus. The length of the thigh portion 17 and crus portion 16 is preferably adjustable. The foot portion 18 comprises connections means 18s for e.g. straps, which allow for connection with the connections means 17s of the thigh portion 17 and as a result, enforcing the movement, i.e. rotation of the joint connecting said foot portion 18 with the crus portion 16, so that the foot portion 18 may follow substantially the same arrangement in respect to the thigh portion 17 during the whole gait cycle. The thigh portion 17 and the crus portion 16 can be provided with means for switching the positions of the connections with the linkage bars 14, 15, for adjustment for various lengths of human extremities.
Analogically, the leg unit 20 comprises a driven disc 21 and a guiding plate 22, connected in portions 21 a and 22a, which guiding plate 22 is guided along a fixed guiding bolt 23 by a guiding slot 22d. The guiding plate 22 is connected with the linkage bars 24, 25 in its portions 22b, 22c respectively, preferably using spherical joints. The linkage bar 24 is connected with a thigh portion 27 and the linkage bar 25 is connected with a crus portion 26, both preferably also using spherical joints. The crus portion 26 comprises a holder 26h for the crus of the person. The thigh portion 27 is pivotally connected with the mounting portion 29 in point 27a. The crus portion 26 is connected pivotally with the thigh portion 27 in point środków 27b. The foot portion 28 is connected pivotally with the crus portion 26 and comprises connection means 28s that are connected with the connection means 27s of the thigh portion 27, so that the foot portion 28 substantially follows its arrangement in respect to the thigh portion 27 throughout the whole cycle of the disc 21 rotation.
The configuration of the linkage 1 is determined by the angular position of a disc 11, which results from the rotation of the shaft of drive 3, with which the disc 11 is coupled using gear means. There are four main angular positions of the disc 11, in which the portion 11a with joint connecting the disc 11 with the guiding plate 12 is situated in four different angular positions in respect to the rotation axis of the disc 11. As shown on the figures 6a - 6d, these positions are located substantially every 90° in respect to the rotation axis of the disc 11, in close proximity to the discs 11 circumference. In accordance to the Fig. 6a - 6d, the disc 11 rotates anti-clockwise. The movement of the guiding plate 12 is determined both by the movement of the portion 11 a of the disc 11 and the fixed position of a guiding bolt 13, coupled with a guiding slot 12d in the guiding plate 12.
For the purpose of this description there have been established the reference directions in respect to the device, as shown on Fig. 5.
Fig. 6a shows the first position of the disc 11 and the corresponding configuration of the linkage 1 and the leg unit 10. In this position, the thigh part 17 and the crus part 16 are aligned substantially in the straight line, imitating a leg in a straight position while standing on the ground. The disc 11 is positioned such that the portion 11 a is situated substantially in its lowest position, i.e. downward in respect to the discs 11 rotation axis. As the disc 11 rotates anti-clockwise from the first position to the position substantially halfway to the second position, the guiding plate 12 and the linkage bars 14, 15 move substantially in the right direction, causing the rotation of the thigh portion 17 and the crus portion 16 around the mounting portion 19 in substantially straight alignment. After said half of the way between the first and the second position, the guiding plate 12 begins to temporarily rotate clockwise around the fixed guiding bolt 13 in connection with its movement to the right. The portion 12c moves substantially downward, causing the anti-clockwise rotation of the crus portion 16 around the thigh part 17 thanks to the linkage bar 15. In the same time the portion 12b moves substantially to the left, which with help of the connection of the portion 12b to the thigh portion 17 by the linkage 14 further assists the rotation of said crus portion 16 around thigh portion 17. This movement imitates the natural bending of the persons leg.
Fig 6b shows the leg unit 10 arrangement while the disc 11 is in the second position. As the disc reaches the second position, the guiding bolt 13 meets with the far most left end of the guiding slot 12d of the guiding plate 12 and constitutes temporarily the rotation axis of the guiding plate 12. After that, during the first half of the discs 11 rotation between the second and third positions, the guiding plate 12 further rotates clockwise and moves slightly left-upward, which causes the maximal imitated bending of the leg. In the second part of the travel between the second and third positions, the guiding plate 12 and linkage bars 14, 15 move substantially up-leftward in substantially unchanged configuration, which causes the rotation of the thigh portion 17 and crus portion 16 around mounting portion 19 also substantially in unchanged configuration.
Fig. 6c shows the third position of the disc 11. During the rotational movement of the disc 11 between the third position and fourth position the portion 12b substantially does not change its position, which results in relatively unchanging position of the linkage bar 14, and as a result, the substantially unchanging position of the thigh portion 17. On the other hand, the portion 12c substantially rotates around the portion 12b, what causes, through the linkage bar 15, the rotation of crus portion 16 around the thigh portion 17. This imitates the straightening of the leg.
Fig. 6d shows the fourth position of the disc. As the disc 11 rotates from the fourth position to the first position, the guiding plate 12 moves substantially right-downward relatively without angular displacement, which causes the further straightening of the leg during the enforced rotation of the thigh portion 17 and crus portion 16 around the mounting portion 19. In the same time, the thigh portion 17 and crus portion 16 return to their substantially co-linear alignment.
The cycle repeats continuously as long as the device is being used. The description relates also to the leg unit 20. It is substantially a mirror image of the left side and all the relations between elements apply correspondingly. The sole difference is that the position of the disc 21 is shifted by a half of the cycle, so that when the disc 11 is in the first position, the disc 21 is in the third position; when the disc 11 is in the second position, the disc 21 is in the fourth position; when the disc 11 is in the third position, the disc 21 is in the first position etc.
Fig. 7 shows a support unit 50. The support unit 50 comprises a support bar 51, on the end of which is situated a support mounting 52. The support bar 51 may comprise adjustment means 56 for adjusting the angle of the support bar 51 in respect to the driving unit 60 and for adjusting the angle of the support mounting 52 in respect to the support bar 51. The support mounting 52 constitute a frame onto which can be attached support means for supporting the body. In this particular embodiment, supporting means comprise front supports 51, side supports 52 and back supports 53. The back supports 53 are mounted so that they can be in the open position for allowing the person to enter the support unit 50 and in closed position to support the persons back after entering. The support unit 50 also comprises mounting portions 19, 29 for mounting the leg units 10, 20 respectively.
Fig. 8 shows a drive unit 60. The drive unit 60 comprises drives 3 with gearing means for driving the discs 11, 21 mounted on the shafts 66. The wheels 65a are also propelled by the drives 3 using gearing means. Preferably, the shafts on which the wheels 65a are mounted are equipped with a differential, to allow turning during operation of the device. The device is supported on side frame arms 62 comprising wheels 65b. The drive unit 60 further comprises a housing 64 for enclosing the internal mechanisms and control means 61 for controlling the device, e.g. turning on/off. The device may be controlled wirelessly via a remote, or according to the programmed algorithm.

Claims

A mobile reciprocal device for enforcing the movement of lower extremities, comprising a mechanical linkage (1) coupled with an orthosis (2) for lower extremities and a drive (3) for enforcing the movement of the linkage (1), characterised in that the linkage (1) is coupled with the drive (3) via a crank mechanism (4).
The mobile reciprocal device according to claim (1), wherein the crank mechanism (4) comprises a disc (11) pivotally fixed with respect to the frame of the device and coupled with a guiding plate (12) comprising a guiding slot (12d) coupled with a guiding bolt (13) fixed with respect to the frame of the device.
The mobile reciprocal device according to claims 1 or 2, wherein the guiding plate (12) comprises a mounting portion (12a) for pivotally connecting with the disc (11) and two mounting portions (12b, 12c) for pivotally connecting with the linkage (1), which comprises linkage bars (14, 15).
The mobile reciprocal device according to claim 3, wherein the orthosis (2) is pivotally mounted in respect to the frame and comprises a thigh portion (17) pivotally joined with a crus portion (16) and wherein the linkage bar (14) is connected to the thigh portion (17) and the linkage bar (15) is connected to the crus portion (16).
The mobile reciprocal device according to any of the preceding claims, wherein the guiding slot (12d) of the guiding plate (12) has a shape of a curved path.