Modular exoskeletal system

Abstract

A modular exoskeletal system (100) for handling at least one hand finger (10) of a user, said modular exoskeletal system (100) comprising at least one finger exoskeleton (120) comprising n ≥ 1 rotational joints (121) and m ≥ 1 link (125) arranged to rotate by means of respective rotational joints (121), said n ≥ 1 rotational joints (121) comprising a fastening rotational joint (121') arranged to allow the rotation of a fastening link (125') about a rotation axis x, said or each finger exoskeleton (120) arranged to transmit an actuation torque M from the fastening link (125') to the hand finger (10). The modular exoskeletal system (100) also comprises an actuation unit (110) comprising an actuator (111) adapted to generate said actuation torque M, at least one Bowden cable (112) comprising an inner cable (112a) and an outer coating (112b), said or each Bowden cable (112) arranged to transmit the actuation torque M to said or each finger exoskeleton (120), a locking device (113) having at least one opening (113') arranged to constrain the outer coating (112b) of the Bowden cable (112) and to allow the inner cable (112a) to slide. In particular, quick coupling means are also comprised arranged for causing the modular exoskeletal system (100) to reversibly pass between an actuated configuration, wherein the actuation unit (110) is connected to said or each finger exoskeleton (120), and a not actuated configuration, wherein the actuation unit (110) is disconnected by said or each finger exoskeleton (120).

Description

Field of the invention

[0001] The present invention relates to the field of haptic devices usable in teleoperation systems, virtual reality or augmented reality, and orthopedic and neurological rehabilitation systems.

[0002] In particular, the invention relates to an exoskeletal system comprising interchangeable modules to be applied to the hand of a user.Description of the prior art

[0003] Haptic devices allow the user to interact with virtual environments by means of sensory feedback. In particular, we distinguish tactile haptic devices (capable of returning tactile sensations proper, such as texture, roughness, vibrations, temperature, etc.) and kinesthetic haptic devices (capable of returning sensations of strength and torque, or information relating to shape, size, weight, compliance of the material, etc.).

[0004] Kinesthetic haptic exoskeletal devices are frequently used in the field of augmented reality or teleoperation, or as real "assistants" to clinicians and physiotherapists in applications that pursue the evaluation and / or functional recovery as a result of orthopedic and neurological trauma. These provide for a simultaneous control of the position and force / torque, so as to exercise different reactions towards the user depending on the forces that the user exerts and depending on the position in which he is. This process is virtually identical to that practiced by the physiotherapist and is based on the same ability to perceive the patient's ability and strength, supporting him, guiding him, exerting appropriate forces and opposing appropriate resistances where necessary with continuous adaptations. Furthermore, the device has a variable virtual weight until it is transparent, that is until it moves under the action of the patient without the patient perceiving the weight to be moved. Finally, it can act as a force multiplier, where necessary, or initiate, and possibly complete, the movement if the patient is not able.

[0005] This haptic operating principle is known in rehabilitation robotics with the name of "assistance as needed".

[0006] Some examples of such devices are reported in US20160259417, WO2015095459, WO2017145136, US20100305717, US9532916, ES2558024, WO2009016478, WO2014033613A3.

[0007] However, all the cited documents provide for a fixed connection of the actuation unit with the exoskeleton acting on the fingers: this makes it more complicated to put on (and remove) the exoskeleton, making it particularly difficult to use for users with spasticity or high flaccidity such as neurological ones, or for users with limited range of motion such as orthopedic ones.

[0008] In addition, this fixed connection prevents you from rapidly changing the size of the exoskeleton, depending on the user's anthropometric measurements, without having to replace the actuation unit as well or perform complicated steps to reconnect the actuation to the final mechanism.

[0009] JP2001166676A discloses an augmented reality tactile simulation system comprising a haptic glove actuation mechanism that uses cables for force transmission. In particular, an electromagnetic clutch is interposed between the system to be implemented and the actuation unit which allows the disconnection of the cable from the actuation unit, in the event that the voltage on the cable exceeds a predetermined threshold. However, JP2001166676A does not provide a quick coupling mechanism between actuation and glove, but only a safety system.

[0010] Document WO2011117901 describes a hand rehabilitation device comprising a quick coupling and release system of the flexible rods that guide the fingers of the hand with respect to the actuation unit that controls them, so as to be able to change the exoskeletal glove by adapting the system to various anthropometric measures. However, this system, comprising a soft type exoskeleton, is limited to the transmission of linear forces and does not allow the transmission of a torque.Summary of the invention

[0011] It is therefore an object of the present invention to provide a modular exoskeletal system for handling at least one hand finger of a user which allows the quick coupling and release of the actuation unit to the exoskeleton acting on the fingers, in order to facilitate the wearing the exoskeleton and being able to quickly replace it according to the anthropometric measurements of the user's hand.

[0012] It is also an object of the present invention to provide such a device which provides abduction and adduction movements of the fingers.

[0013] These and other objects are achieved by a modular exoskeletal system for handling at least one hand finger of a user according to claims 1 to 10.Brief description of the drawings

[0014] Further characteristic and / or advantages of the present invention are more bright with the following description of an embodiment thereof, exemplifying but not limitative, with reference to the attached drawings in which: Fig. 1 shows a perspective view of a possible embodiment of the modular exoskeletal system comprising also the actuation unit; Fig. 2A shows in detail some components of the modular exoskeletal system OF Fig. 1 in the not actuated configuration; Fig. 2B shows in detail the components of the modular exoskeletal system OF Fig. 2A in the actuated configuration; Fig. 3A shows in detail the locking device; Figs. 3B and 3C show in detail the pulley and the Bowden cable to it connected; Figs. 4A and 4B show a first embodiment of the quick coupling means; Figs. 5A and 5B show a second embodiment of the quick coupling means; Figs. 6A and 6B show a third embodiment of the quick coupling means; Figs. 7A and 7B show a possible embodiment of the quick coupling means of the locking device; Figs. 8A and 8B show a possible embodiment of the quick coupling means of the locking device; Figs. 9A and 9B show a possible embodiment of the quick coupling means of the locking device; Figs. 10A and 10B show an embodiment of the quick coupling means wherein a cam mechanism is provided to facilitate the assembly and disassembly of the exoskeleton; Fig. 11 shows a possible coupling system between the finger exoskeleton and the support plate; Fig. 12 shows an exoskeletal system, similar to the embodiment of Fig. 1, comprising 3 finger exoskeletons. Description of a preferred embodiment

[0015] With reference to Fig. 1, a modular hand exoskeletal system 100 for handling at least one hand finger of a user, according to the present invention, comprises an actuation unit 110 and at least one finger exoskeleton 120. The system 100 may also comprise a support plate 140 arranged to fasten one or more finger exoskeletons 120 to the user's hand.

[0016] In particular, with reference even at Figs. 2A and 2B, the finger exoskeleton comprises a number m ≥ 1 of link 125 arranged to rotate about a number n ≥ 1 of respective rotational joints 121 for transmitting at least one actuation torque M from a fastening link 125' to the hand finger 10.

[0017] Furthermore, the actuation unit 110 comprises an actuator 111 adapted to generate the actuation torque M to be transmitted to the fastening link 125' through one or two Bowden cables 112. In particular, each Bowden cable 112 comprises, as well known, an inner cable 112a and an outer coating 112b. With reference even at Fig. 3A, the actuation unit also comprises a locking device 113 that, by means of the two apertures 113' obtained by the union of two portions 113a and 113b, allows to lock the end of the outer coatings 112b and to instead make the inner cable 112a to slide.

[0018] The modular hand exoskeletal system 100 then comprises quick coupling means arranged to cause the modular exoskeletal system 100 to pass between an actuated configuration, wherein the actuation unit 110 is connected to the finger exoskeleton 120 for transmitting the actuation torque M to the fastening link 125', and a not actuated configuration, wherein the actuation unit 110 is disconnected by the finger exoskeleton 120.

[0019] In particular, the quick coupling means comprises a transmission element 130, steadily connected to at least one inner cable 112a, and arranged to reversibly connect to the fastening link 125' generating an interlocking constraint.

[0020] This way, when the modular hand exoskeletal system 100 is in the actuated configuration, the transmission element 130 is connected to the fastening link 125' and the interlocking constraint allows the transmission of the actuation torque M rotating the fastening link 125' about its rotation axis x.

[0021] In particular, in the embodiment of Figs. 2A and 2B, the transmission element 130 is a pulley that is adapted, in the actuated configuration, to be rotated by the inner cables 112a to rotate the fastening link 125' about a rotation axis x.

[0022] The present invention therefore allows both to facilitate the wearing of the exoskeleton 120, and to be able to quickly replace it according to the anthropometric measurements of the user's hand.

[0023] Furthermore, owing to the locking device 113, the invention makes it possible to maintain the pre-set tension on the cable unchanged and to avoid the need for a new adjustment of the tension of the cable at each disconnection and reconnection of the exoskeleton 120.

[0024] With reference even at Figs. 3B and 3C, in a first embodiment of the quick coupling means, the pulley 130, to which the Bowden cables 112 are connected, comprises a plurality of elongated elements 131, in particular pins. Such pulley 130 is connected by means of magnetic force to the fastening rotational joint 121', allowing the transmission of the actuation torque M to the fastening link 125' thanks to the pins 131 which are inserted into the holes 126' generating the interlocking constraint.

[0025] Figures 4A, 4B, 5A, 5B, 6A and 6B show three embodiments of the quick coupling means, alternative with respect to that of Figs. 1 to 3B, both in the actuated configuration and in the not actuated configuration.

[0026] In particular, in Figs. 4A, 4B, 5A and 5B, two embodiments are shown in which the transmission element 130 is a pulley comprising two portions 130a and 130b arranged to connect to lock the ends 112a of the inner cables 112a to the pulley 130. In both the embodiments, as in the solution of Fig. 3B, elongated elements 131 are provided, such as pins or screws, arranged, in the actuated configuration, to be inserted into the holes 126', generating the interlocking constraint, for transmitting the actuation torque M to the fastening link 125'.

[0027] In the embodiment of Figs. 6A and 6B, the transmission element 130 is a shaped element comprising two portions 130a and 130b, arranged to connect to lock the ends 112a of the inner cables 112a. In this embodiment, the fastening link 125' comprises a receiving element 130c having complementary geometry with respect to the transmission element 130. In particular, the portion 130a comprises a tooth 131a that is adapted, in the actuated configuration, to be inserted into the hole 126a', generating the interlocking constraint, for transmitting the actuation torque M to the fastening link 125'.

[0028] In general, in all the embodiments described, the transmission element 130, in the actuated configuration, can be constrained to the fastening link 125'by means of magnets 135 arranged to produce a magnetic force acting in a direction parallel to the rotation axis x.

[0029] In the figures 7A, 7B, 8A and 8B, two possible embodiments of the quick coupling means are shown that allow the easy connection of the locking device 113 to an engagement portion 129 of the finger exoskeleton 120. In particular, in an embodiment of Figs. 7A and 7B a "snap fit" system is provided, while in Figs. 8A and 8B pins 114 are provided connected to the locking device 113 and arranged to fit into the grooves 129'.

[0030] In both embodiments, the engagement portion 129 defines an engagement axis y at which the locking device 113 is adapted to engage. Such engagement axis y is arranged at a determined distance D by the rotation axis x, in order to allow, at the moment of quick coupling, to provide a tension to the inner cables 112a such as to allow a prompt transmission of the actuation torque M to the pulley 130.

[0031] This way, it is sufficient to adjust only once the tension required to the cables Bowden 112, by adjustment means located near the actuator 111. Then, the distance D will guarantee, at each passage between not actuated configuration and actuated configuration, that the Bowden cables 112 are subjected to the correct tension for transmitting the motion. Furthermore, in an embodiment not shown in the figure, adjustment means can also be provided arranged to translate the engagement axis y for adjusting the distance D.

[0032] Such aspect allows the present invention to pass between the not actuated configuration and the actuated configuration much faster than the prior art, since, in addition to having an easy connection system between actuation unit 110 and exoskeleton 120, it also allows to avoid the adjustment of the tension of the cable at each coupling.

[0033] In the figures 9A and 9B an embodiment is shown of the quick coupling means wherein the locking device 113 is integral to the pulley 130 by means of a bridge 114, so as to maintain the distance D constant also in the not actuated configuration and to further facilitate the connection of the exoskeleton 120, maintaining the adjustment of the cable.

[0034] In the figures 10A and 10B an embodiment of the quick coupling means is shown wherein a cam mechanism 115 is provided to facilitate the assembly and the disassembly of the exoskeleton 120. In particular, the cam mechanism 115 passes between a release configuration (Fig. 10A), in which the cables 112a are loosened, and an operating configuration (Fig. 10B), in which the cables have the optimal tension to actuate the exoskeleton 120.

[0035] This way, when the exoskeleton 120 must be released, it is possible to set the cam mechanism 115 in the release configuration, allowing the exoskeleton 120 to be disconnected with less force, as the friction due to the interlocking constraint between the pulley 130 and the fastening link 125' is less. Still in the release configuration, the exoskeleton 120 can be re-engaged without effort. Once the exoskeleton 120 has been brought into position, the cam mechanism 115 can be returned to the operating configuration, restoring the adjusted tension in the cable and allowing an optimal actuation.

[0036] In Fig. 11, an embodiment of the invention is shown wherein a support plate 140 is also provided arranged to be integrally constrained to the hand of the user and to allow a removable connection with the finger exoskeleton 120. In particular, the finger exoskeleton 120 is rotoidally connected by inserting the pin 128 in one of the holes 142 by means of magnets 150. This way, the exoskeleton 120 can rotate about its axis z following the adduction and abduction movements of the finger. Furthermore, to ensure grip between exoskeleton 120 and support plate 140, without preventing the rotation about its axis z, the plate comprises an iron-magnetic plate 141 arranged to attract the magnets 151 integral with the exoskeleton 120.

[0037] Fig. 12 shows an embodiment of the modular exoskeletal system 100 (the actuation unit is not shown for simplicity) wherein the support plate 140 is connected to the palm of the user's hand and two finger exoskeletons 120 are connected to it. A third finger exoskeleton 120 for thumb is also provided having its own support plate 140' independent from the other fingers. This allows adjusting the plane of opposition of the thumb with respect to the other fingers.

[0038] The foregoing description some exemplary specific embodiments will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and / or adapt in various applications the specific embodiments without further research and without parting from the invention, and, accordingly, it is meant that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the scope of the invention which is defined by the claims. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.

Claims

1. A modular exoskeletal system (100) for handling at least one hand finger (10) of a user, said modular exoskeletal system (100) comprising: - at least one finger exoskeleton (120) comprising n ≥ 1 rotational joints (121) and m ≥ 1 link (125) arranged to rotate by means of respective rotational joints (121), said n ≥ 1 rotational joints (121) comprising a fastening rotational joint (121') arranged to allow the rotation of a fastening link (125') about a rotation axis x, said or each finger exoskeleton (120) arranged to transmit an actuation torque M from said fastening link (125') to said hand finger (10); - an actuation unit (110) comprising: - an actuator (111) adapted to generate said actuation torque M; - at least one Bowden cable (112) comprising an inner cable (112a) and an outer coating (112b), said or each Bowden cable (112) arranged to transmit said actuation torque M to said or each finger exoskeleton (120); - a locking device (113) having at least one opening (113') arranged to constrain said outer coating (112b) of said Bowden cable (112) and to allow said inner cable (112a) to slide; - quick coupling means arranged for causing said modular exoskeletal system (100) to reversibly pass between an actuated configuration, wherein said actuation unit (110) is connected to said or each finger exoskeleton (120), and a not actuated configuration, wherein said actuation unit (110) is disconnected by said or each finger exoskeleton (120); wherein said quick coupling means comprises a transmission element (130) steadily connected to said or each inner cable (112a), said transmission element (130) arranged to connect to said fastening link (125') in a reversible manner by means of an interlocking constraint; and wherein, in said actuated configuration, said transmission element (130) is connected to said fastening link (125') and said interlocking constraint is arranged to transmit said actuation torque M from said actuation unit (110) to said fastening link (125') rotating said fastening link (125') about said rotation axis x.

2. The modular exoskeletal system (100), according to claim 1, wherein said transmission element (130) comprises a pulley that is adapted, in said actuated configuration, to be rotated by said or each inner cable (112a) to bring in rotation said fastening link (125') about said rotation axis x.

3. The modular exoskeletal system (100), according to claim 1, wherein said finger exoskeleton (120) comprises an engagement portion (129) arranged to define a engagement axis y at which said locking device (113) is adapted to engage with said finger exoskeleton (120) by means of said quick coupling means, and wherein said rotation axis x and said engagement axis y are at a determined distance D such as to provide a tension to said inner cable (112a) in such a way that it allows the transmission of said actuation torque M to said transmission element (130).

4. The modular exoskeletal system (100), according to claim 3, wherein said finger exoskeleton (120) comprises an adjustment means arranged to actuate said engagement axis y for adjusting said determined distance D.

5. The modular exoskeletal system (100), according to claim 1, wherein said transmission element (130) comprises at least one elongated element (131) and said fastening link (125') comprises at least one hole (126'), and wherein, in said actuated configuration, said or each elongated element (131) is arranged to enter a respective hole (126') generating said interlocking constraint.

6. The modular exoskeletal system (100), according to claim 1, wherein said fastening link (125') comprises a receiving element (130c), and wherein said transmission element (130) and said receiving element (130c) have a complementary geometry configured, in said actuated configuration, for generating said interlocking constraint.

7. The modular exoskeletal system (100), according to claim 1, wherein, in said actuated configuration, said transmission element (130) is connected to said fastening link (125') by means of magnetic force.

8. The modular exoskeletal system (100), according to one of claims 3 or 4, wherein said quick coupling means comprise a "snap fit" system for quickly connecting said locking device (113) to said engagement portion (129).

9. The modular exoskeletal system (100), according to any of the previous claims, wherein a support plate (140) is also provided arranged to be integrally constrained to said hand of said user and wherein said finger exoskeleton (120) is adapted to be removably constrained to said support plate (140).

10. The modular exoskeletal system (100), according to claim 9, wherein said finger exoskeleton (120) can move with respect to said support plate (140) according to a rotation axis adapted to allow an abduction and adduction of said finger.

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