EXOSKELETON COMPRISING A PLURALITY OF AUTONOMOUSLY OPERABLE MODULES

Abstract

An exoskeleton (1) having a plurality of autonomously operable modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) each having a dedicated controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) connected to an actuated joint. The exoskeleton (1) further having a multimaster electrical communicator (3) between the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH). The controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured for: collecting information from sensors; sharing information with the remaining modules through the multimaster electrical communicator (3); determining which other modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) are present; and autonomously calculating and commanding a desired trajectory of the actuated joint of the module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) for assisting the movement of the corresponding biological joint in coordination with the kinematic condition of other biological joints.

Claims

1. An exoskeleton (1) comprising a plurality of autonomously operable modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) each configured for assisting a corresponding biological joint of a patient wearing the exoskeleton (1), wherein each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) comprises a mechanical structure comprising one actuated joint, the mechanical structure further comprising fastening means (21.sub.RK, 21.sub.LK, 21.sub.RH, 21.sub.LH) for fastening the module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) to said corresponding biological joint, the mechanical structure further comprising releasable mechanical coupling means for releasably coupling each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) to at least one adjacent module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH), and wherein each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) further comprises a plurality of sensors (22) configured to determine the kinematic condition of the corresponding biological joint said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured to be fastened to, each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) further comprises a dedicated controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) connected to the actuated joint of said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH), the exoskeleton (1) further comprises multimaster electrical communication means (3) between the dedicated controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) for sharing the kinematic condition of the biological joints each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is fastened to, and where the dedicated controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured for: collecting information determining the kinematic condition of the corresponding biological joint said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured to be fastened to from the sensors belonging to said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH), sharing said information with the remaining modules through the multimaster electrical communication means (3), determining which other modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) of the exoskeleton (1) the patient is wearing based on the information available through the multimaster electrical communication means (3), and autonomously calculating and commanding, based on the information about the kinematic condition of the biological joints of the patient shared through the multimaster electrical communication means (3), a desired trajectory of the actuated joint of said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) for assisting the movement of the corresponding biological joint in coordination with the kinematic condition of other biological joints, such that the exoskeleton (1) operates according to a multi-master decentralized control strategy which does not require the patient to wear all the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH).

2. The exoskeleton (1) according to claim 1, wherein the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) are configured for assisting a corresponding biological joint of a lower limb of the patient wearing the exoskeleton (1).

3. The exoskeleton (1) according to claim 2, comprising a right knee module (2.sub.RK), a left knee module (2.sub.LK), a right hip module (2.sub.RH), and a left hip module (2.sub.LH), and further comprising a lumbar support (4) configured to be coupled to the right hip module (2.sub.RH) and/or the left hip module (2.sub.LH).

4. The exoskeleton (1) according to claim 3, wherein the controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) autonomously calculates and commands the desired trajectory of the actuated joint of said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) based on the kinematic condition of adjacent biological joints and on the kinematic condition of the opposite biological joint, where the exoskeleton (1) is operable in the following configurations: full exoskeleton (1) comprising the right knee module (2.sub.RK), the left knee module (2.sub.LK), the right hip module (2.sub.RH) and the left hip module (2.sub.LH); partial exoskeleton (1) consisting of the right knee module (2.sub.RK), the left knee module (2.sub.LK), the right hip module (2.sub.RH) or the left hip module (2.sub.LH) alone; partial exoskeleton (1) consisting of the right hip module (2.sub.RH) and the right knee module (2.sub.RK), and thus lacking the left hip module (2.sub.LH) and the left knee module (2.sub.LK); partial exoskeleton (1) consisting of the left hip module (2.sub.LH) and the left knee module (2.sub.LK), and thus lacking the right hip module (2.sub.RH) and the right knee module (2.sub.RK); partial exoskeleton (1) consisting of the right hip module (2.sub.RH) and the left hip module (2.sub.LH), and thus lacking the right knee module (2.sub.RK) and the left knee module (2.sub.LK); and partial exoskeleton (1) consisting of the right knee module (2.sub.RK) and the left knee module (2.sub.LK), and thus lacking the right hip module (2.sub.RH) and the left hip module (2.sub.LH).

5. The exoskeleton (1) according to claim 1, wherein the multimaster electrical connection means (3) between the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) comprise wired multimaster electrical connection means.

6. The exoskeleton (1) according to claim 5, wherein the wired multimaster electrical connection means (3) between the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured to run from the controller (23.sub.RK) of the module (2.sub.RK) closest to the right foot of the patient, upwards along said right lower limb for connection with all right limb controllers (23.sub.RH), crosswise along the lumbar region of the patient, and then downwards along the lower limb for connection with all left limb controllers (23.sub.LH) down to the controller (23.sub.LK) of the module (2.sub.LK) closest to the left foot of the patient.

7. The exoskeleton (1) according to claim 1, wherein the multimaster electrical connection means (3) comprise wireless multimaster electrical connection means.

8. The exoskeleton (1) according to claim 1, wherein each dedicated controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) comprises a dedicated memory means (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH) for storing a global database containing information determining the kinematic condition of the biological joints each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured to be fastened to.

9. The exoskeleton (1) according to claim 1, wherein the releasable mechanically coupling means between adjacent modules comprise a slider tube in one module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) suitable to be received by a complementary slider cavity in another module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH), where said releasable mechanically coupling means are adjustable as to the distance between said adjacent modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH).

10. A method for operating an exoskeleton (1) comprising a plurality of autonomously operable modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) each configured for assisting a corresponding biological joint of a patient wearing the exoskeleton (1), where each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) comprises a mechanical structure comprising one actuated joint, the mechanical structure further comprising fastening means (21.sub.RK, 21.sub.LK, 21.sub.RH, 21.sub.LH) for fastening the module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) to said corresponding biological joint, the mechanical structure further comprising releasable mechanical coupling means for releasably coupling each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) to at least one adjacent module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH), where each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) further comprises a plurality of sensors configured to determine the kinematic condition of the corresponding biological joint said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured to be fastened to, where each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) further comprises a dedicated controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) connected to the actuated joint of said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH), and where the exoskeleton (1) further comprises multimaster electrical communication means (3) between the dedicated controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) for sharing the kinematic condition of the biological joints each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is fastened to, the method being wherein exoskeleton (1) operates according to a multi-master decentralized control strategy which does not require the patient to wear all the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH), where each dedicated controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) carries out the following steps: collecting information determining the kinematic condition of the corresponding biological joint said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured to be fastened to from the sensors of the module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) comprising said dedicated controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH); sharing said information with the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of the remaining modules through the multimaster electrical communication means (3); determining which other modules of the exoskeleton (1) the patient is wearing based on the information available through the multimaster electrical communication means (3); and autonomously calculating and commanding a desired trajectory of the actuated joint of said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) for assisting the movement of the corresponding biological joint in coordination with the kinematic condition of other biological joints.

11. The method according to claim 10, where the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) are configured for assisting a corresponding biological joint of a lower limb of the patient wearing the exoskeleton (1).

12. The method according to claim 10, further comprising the steps of: storing the information determining the kinematic condition of the corresponding biological joint each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is configured to be fastened to in a respective global database comprised in the dedicated memory means (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH) of each controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH); and each controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) updating said global database by accessing periodically to the electrical communication means (3).

13. The method according to claim 10, wherein the step of calculating the desired trajectory of the actuated joint of a module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is carried out using a neural network of Central Pattern Generator algorithms comprising adaptive Hopf oscillators.

14. The method according to claim 13, wherein each Central Pattern Generator algorithm is previously trained with a desired trajectory of the corresponding biological joint by means of a Dynamic Hebbian learning method applied to adaptive Hopf oscillators.

15. The method according to claim 13, wherein the neural network of Central Pattern Generator algorithms comprises coordination terms (k.sub.j) for ensuring coordination between actuated joints of a limb and coordination between actuated joints of opposite limbs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0071] FIG. 1 shows a perspective view of an exemplary modular exoskeleton according to the present invention comprising a right hip module, a left hip module, a right knee module and a left knee module in a full configuration.

[0072] FIGS. 2a-2e show perspective views of the exemplary modular exoskeleton in five partial configurations each consisting of a particular subset of the modules.

[0073] FIG. 3 shows a typical centralized control architecture employed in exoskeletons known from the prior art.

[0074] FIG. 4 shows the distributed control architecture of the exemplary modular exoskeleton according to the present invention.

[0075] FIG. 5 shows in further detail the architecture of the electrical connections between the modules of the exemplary exoskeleton according to the present invention.

[0076] FIG. 6 shows schematically the structure of a database used in the exemplary modular exoskeleton according to the present invention.

[0077] FIGS. 7a-7b schematically show what information the exemplary modular exoskeleton in the full configuration collects from the global database.

[0078] FIGS. 8a-8b schematically show what information the exemplary modular exoskeleton in a partial configuration including only the two hip modules collects from the global database.

[0079] FIGS. 9a-9b schematically show what information the exemplary modular exoskeleton in a partial configuration including only the right hip and right knee modules collects from the global database.

[0080] FIGS. 10a-10b schematically show what information the exemplary modular exoskeleton in a partial configuration including only the two knee modules collects from the global database.

[0081] FIGS. 11a-11b schematically show what information the exemplary modular exoskeleton in a partial configuration including only the left hip module collects from the global database.

[0082] FIGS. 12a-12b schematically show what information the exemplary modular exoskeleton in a partial configuration including only the right knee module collects from the global database.

[0083] FIG. 13 is a diagram showing the most relevant steps of the operation method of the exoskeleton of the invention.

[0084] FIG. 14 is a schematic drawing showing the main components of a module of the exemplary modular exoskeleton.

[0085] FIG. 15 shows, in connection with the learning process of hip angular position, the gait signal to learn (dashed line) and the result of learning (solid line) at the beginning in the upper graph and at the end in the lower graph.

[0086] FIG. 16 shows, in connection with the learning process of knee angular position, the gait signal to learn (dashed line) and the result of learning (solid line) at the beginning in the upper graph and at the end in the lower graph.

[0087] FIG. 17 shows the angular trajectories generated by each of the four joint modules CPGs—right hip, right knee, left hip and left knee—in synchronism.

[0088] FIG. 18 shows the angular trajectories of four joint modules—right hip, right knee, left hip and left knee—in synchronism while changing the frequencies ω.sub.swing and ω.sub.stance.

DESCRIPTION OF WAYS OF CARRYING OUT THE INVENTION

Description of the Exoskeleton

[0089] In the present example, an exemplary exoskeleton (1) directed to assist the lower limbs of a patient is disclosed. In particular, the exoskeleton (1) is directed to assist the flexion/extension of the biological hip joints and the flexion/extension of the biological knee joints. Note, however, that there is no limitation as to the number and position of the biological joints an exoskeleton according to the present invention can assist. For example, in connection with a lower limb exoskeleton, the ankle joint may also be assisted. Furthermore, several different type of movements may be assisted in each of the joints, including flexion/extension, abduction/adduction, rotation, etc. The set of joints assisted by the exoskeleton (1) shown in the figures is merely exemplary and by no means must be considered limiting. The concept underlying the present invention is applicable irrespective of the joints the relevant exosleketon is configured to assist.

[0090] FIG. 1 shows a perspective view of the exemplary exoskeleton (1) in a full configuration. FIGS. 2a-2e show respective perspective views of the exemplary exoskeleton (1) according to partial configurations, in particular a configuration consisting of the right and left knee modules (FIG. 2a), a configuration consisting of the left knee module alone (FIG. 2b), a configuration consisting of the left knee and hip modules (FIG. 2c), a configuration consisting of the left hip module alone (FIG. 2d), and a configuration consisting of the right and left hip modules (FIG. 2e).

[0091] In the present example, the actuated joints are particularly powered joints. The powered joints therefore comprise a motor connected to the joint by means of a gear mechanism for adapting the velocity of the motor to the desired velocity of the joint. The powered joints may also comprise an elastic element configured for ensuring a smooth transmission of power from the motor to the joint.

[0092] The exemplary exoskeleton (1) comprises four modules: a right knee module (2.sub.RK), a left knee module (2.sub.LK), a right hip module (2.sub.RH), and a left hip module (2.sub.LH). The exemplary exoskeleton (1) further comprises a lumbar support (4). These components are now disclosed in more detail. [0093] a) Right knee module (2.sub.RK) [0094] The right knee module (2.sub.RK) comprises a right thigh segment and a right calf segment connected by a right knee powered joint. The right calf segment is a vertical rod protruding downwardly from a cover housing the powered joint, as well as relevant electrical components of the right knee module (2.sub.RK). The cover itself makes up the right thigh segment in this embodiment. Naturally, the right thigh segment comprises fastening means (21.sub.RK) configured to be fastened to the right thigh of the patient, while the right calf segment comprises fastening means (21.sub.RK) configured to be fastened to the right calf of the patient. The fastening means could be just bands provided with complementary loop and hook surfaces such as, e.g. Velcro®. Alternatively, or additionally, the fastening means could comprise an essentially semicylindrical shell designed for receiving the thigh or calf. In any case, when the right knee module (2.sub.RK) is worn by the user with the segments respectively fastened to the thigh and calf, the right knee joint of the module is immediately adjacent side-by-side the right knee biological joint of the patient. [0095] The right knee module (2.sub.RK) further comprises coupling means for mechanical coupling to the right hip module (2.sub.RH) when both modules are used at the same time (see FIG. 2b where the exoskeleton (1) is formed by one hip module (2.sub.LH) and one knee module (2.sub.LK) of the same leg). Indeed, in this exemplary embodiment, the only adjacent module to the right knee module (2.sub.RK) is the right hip module (2.sub.RH). Therefore, in case the patient wears both the right knee module (2.sub.RK) and the right hip module (2.sub.RH) at the same time, these two modules must be mechanically coupled. The coupling means of the right knee module (2.sub.RK) comprises a pair of grooves provided on lateral sides of the cover. As shown in FIG. 2a, the cover has a substantially parallelepipedic configuration having parallel opposing lateral sides where the grooves are provided. As mentioned above, fastening means (21.sub.RK, 21.sub.RH) are provided for attaching the exoskeleton to the right thigh of the patient. These fastening means (21.sub.RK, 21.sub.RH) are shared by the right knee module (2.sub.RK) and the right hip module (2.sub.RH). A pair of rails are provided on an external surface of said fastening means (21.sub.RK, 21.sub.RH) i.e. a surface that, when worn by the patient, is oriented outwardly with respect to the leg of the patient. The pair of rails are intended to match the aforementioned grooves provided on the lateral sides of the cover of the right knee module (2.sub.RK). Thus, the cover of the right knee module (2.sub.RK) can be suitably coupled to the fastening means (21.sub.RK, 21.sub.RH) by displacing the cover from below such that the grooves advance upwardly along the rails. Similarly, a corresponding cover comprising the electrical components of the right hip module (2.sub.RH) can be connected to an opposite end of the rails provided on the external surface of the fastening means (21.sub.RK, 21.sub.RH) by advancing said cover downwardly along the rails. Furthermore, the covers of the right knee module (2.sub.RK) and the right hip module (2.sub.RH) have complementary shapes such that, when both are coupled to the fastening means (21.sub.RK, 21.sub.RH), their shapes match. The two modules (2.sub.RK, 2.sub.RH) thus coupled then mechanically behave as a single lower limb unit sharing the thigh fastening means (21.sub.RK, 21.sub.RH). [0096] The right knee module (2.sub.RK) further comprises sensors for determining the kinematic condition of the right knee biological joint. Preferably, these sensors comprise inertial motion units, angular position sensors, and force sensors. These sensors can be provided in any position of the structure of the right knee module (2.sub.RK). In particular, the right knee module preferably further comprises a GRF sensor placed at a platform provided at the lower end of the right calf segment for supporting the foot of the patient. In any case, the number and position of the sensors of the right knee module (2.sub.RK) is selected according to known considerations such that the information obtained is enough to sufficiently characterized the kinematic condition of the right knee biological joint of the patient. Furthermore, the communication between the sensors and the relevant controller (23.sub.RK) can be wired or wireless depending on the application. [0097] Now, unlike in prior art exoskeletons, the right knee module (2.sub.RK) of the present exoskeleton further comprises a right knee controller (23.sub.RK) configured to autonomously calculate and command a desired trajectory for the right knee powered joint. Indeed, since the right knee module (2.sub.RK) is configured to be in electrical communication with other modules, i.e. the right hip module (2.sub.RH), the left hip module (2.sub.LH) and/or the left knee module (2.sub.LK), if worn by the patient, the right knee module (2.sub.RK) is provided with all the information regarding the kinematic condition of those joints that need to be taken into account for rendering a natural gait when the patient walks aided by the exoskeleton (1). [0098] b) Right hip module (2.sub.RH) [0099] The right hip module (2.sub.RH) comprises a lumbar segment and a right thigh segment connected by a right hip actuated joint. The right thigh segment comprises fastening means (21.sub.RH) of the same type disclosed above, i.e. bands provided with hook and loop surfaces for firmly fastening to the thigh of the patient, and/or shells for receiving the thigh. The lumbar segment is configured to be coupled to the lumbar support (4) which, when worn, abuts against a lumbar area of the patient. The lumbar segment is configured to be coupled to the lumbar support (4) by means of a lumbar support coupling means comprising an adjustable regulation system allowing for the distance between hip module (2.sub.RH) and lumbar support (4) to be modified according to the needs of the patient. In any case, when the right hip module (2.sub.RH) is worn by the user with the segments respectively fastened to the thigh and lumbar support, the right hip actuated joint of the module is immediately adjacent side-by-side the right hip biological joint of the patient. [0100] The right hip module (2.sub.RH) further comprises coupling means for coupling the right hip module with the right knee module, if worn by the user. These coupling means were disclosed in previous paragraphs. The right hip module (2.sub.RH) further comprises means for coupling the right hip module (2.sub.RH) to the left hip module (2.sub.LH) when both are used at the same time (see FIG. 2e where the exoskeleton (1) is formed by the right hip module (2.sub.RH) to the left hip module (2.sub.LH)). Note that, when a hip module (2.sub.RH, 2.sub.LH) is worn by the user, said hip module (2.sub.RH, 2.sub.LH) is always coupled to the lumbar support (4). Therefore, when both hip modules (2.sub.RH, 2.sub.LH) are worn by the user, they are both connected to opposite sides of the lumbar support (4) by means of the respective lumbar support coupling means, i.e. they are both connected one to the other. [0101] The right hip module (2.sub.RH) further comprises sensors for determining the kinematic condition of the right hip biological joint. Preferably, these sensors comprise inertial motion units, angular position sensors, and force sensors. These sensors can be provided in any position of the structure of the right hip module (2.sub.RH). In particular, the right hip module (2.sub.RH) comprises a shoulder orientation sensor intended to detect the orientation of the shoulder of the patient. Thereto, the shoulder orientation sensor may be fastened to the shoulder of the patient, i.e. by attaching it to the clothing of the patient or else using dedicated means such as a band provided with Velcro® or the like. In any case the number and position of the sensors of the right hip module (2.sub.RH) is selected according to known considerations such that the information obtained is enough to sufficiently characterize the kinematic condition of the right hip biological joint of the patient. [0102] The right hip module (2.sub.RH) further comprises a right hip controller (23.sub.RH) configured to autonomously calculate and command a desired trajectory for the right hip powered joint. Indeed, since the right hip module is configured to be in electrical communication with other modules, i.e. the left hip module, the right knee module and/or the left knee module, if worn by the patient, the right hip module (2.sub.RH) is provided with all the information regarding the kinematic condition of those joints that need to be taken into account for rendering a natural gait when the patient walks aided by the exoskeleton. [0103] c) Left knee module (2.sub.LK) [0104] The mechanical configuration of the left knee module (2.sub.LK) is similar to that disclosed above with respect to the right knee module (2.sub.RK). [0105] d) Left hip module (2.sub.LH) [0106] The mechanical configuration of the left hip module (2.sub.LH) is similar to that disclosed above with respect to the left hip module (2.sub.LH). [0107] e) Lumbar support (4) [0108] The lumbar support (4) is known in this field to provide better and more convenient support for the exoskeleton (1) whenever a hip module (2.sub.RH, 2.sub.LH) is present. The lumbar support (4) comprises an essentially flat or thin pad configured to abut against the lumbar area of the patient. Known dedicated fastening means are used for fastening the lumbar support to the patient, such as e.g. bands having Velcro® surfaces of the like. The lumbar support is used always in combination with either of the hip modules, or with both.

[0109] In all cases, multimaster electrical communication means (3) are provided to connect the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) present in the particular exoskeleton configuration (1). When in the full exoskeleton (1) configuration, the communication means (3) are preferably a multimaster bus running from the controller (23.sub.RK) of the right knee module (2.sub.RK), upwards along said right leg for connection with the controller (23.sub.RH) of the right hip module (2.sub.RH), crosswise along the lumbar region of the patient towards the controller (23.sub.LH) of the left hip module (23.sub.LH), and then downwards along the left leg for connection to the controller (23.sub.LK) of the left knee module (2.sub.LK). In other configurations the communication means (3) are adapted in accordance with the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) present in the exoskeleton (1).

[0110] These four modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) and the lumbar support (4) can be combined for rendering a number of different exoskeleton configurations (1), some of which are shown in FIG. 1 and FIGS. 2a-2e.

[0111] In FIG. 1, a full exoskeleton (1) is shown comprising all four modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) and the lumbar support (4). The knee modules (2.sub.RK, 2.sub.LK) are coupled to the respective hip modules (2.sub.RH, 2.sub.LH) by means of the rail and groove coupling means disclosed above, both therefore sharing the thigh fastening means.

[0112] In FIG. 2a, a configuration having only the knee modules (2.sub.RK, 2.sub.LK) is shown.

[0113] In FIG. 2b, a configuration having only one knee module (2.sub.LK) is shown.

[0114] In FIG. 2c, a configuration having the left knee module (2.sub.LK) and the left hip (2.sub.LH) module is shown. In this case, again the left knee module (2.sub.LK) is coupled to the left hip module (2.sub.LH) using the rail and groove coupling means disclosed above. Also, in this case the left hip module (2.sub.LH) is connected to the lumbar support (4).

[0115] In FIG. 3d, a configuration having only the left hip module (2.sub.LH) is shown.

[0116] In FIG. 3e, a configuration having the left hip module (2.sub.LH) and the right hip module (2.sub.RH) is shown.

[0117] FIG. 3 shows a schematic view of the centralized control architecture corresponding to a prior art exoskeleton. A centralized main control processor, i.e. master, is connected to a number of peripheral joint motor drivers, i.e. slaves, corresponding to the powered joints of the exoskeleton. The centralized main control processor carries out all the processing steps for receiving sensor information, calculating a trajectory for each powered joint in a coordinated manner for ensuring a natural gait, and then providing the corresponding signals to the drivers for actuating the joints. The centralized main control processor is usually located at the lumbar support.

[0118] This configuration requires the centralized main control processor to always be present for the exoskeleton to operate. Therefore, even if the exoskeleton allowed a particular powered joint to be dispensed with, still the centralized control processor, and therefore the lumbar support, needs to be worn by the patient. This configuration does not allow any flexibility as to the number and position of the powered joints comprised by the exoskeleton.

[0119] FIG. 4 shows the control architecture used by the exoskeleton (1) of the present invention. There is no centralized main control processor, i.e. there is no master controller. On the other hand, each and every module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) comprises a dedicated controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH). Therefore, in the present example, the right knee module (2.sub.RK) comprises a right knee controller (23.sub.RK), the left knee module (2.sub.LK) comprises a left knee controller (23.sub.LK), the right hip module (2.sub.RH) comprises a right hip controller (23.sub.RH), and the left hip module (2.sub.LH) comprises a left hip controller (23.sub.LH). These four controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) are connected to a multimaster electrical communication means (3) ensuring that the information obtained by the sensors belonging to each of the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is automatically shared with the other modules. Thereby, each of the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) can calculate and command the trajectory only of the corresponding powered joint in coordination with the trajectory of the rest of the powered joints present in the exoskeleton (1) at any given moment.

[0120] FIG. 5 shows this architecture in more detail. Each controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) comprises a corresponding processor and memory (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH). Each memory (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH) stores a global data base with the information provided with all the sensors of the exoskeleton (1). In the present exemplary exoskeleton (1), the sensors are those shown in the chart of FIG. 6. The sensors connected to the left hip controller (23.sub.LH) are left hip angle, left hip force, and left shoulder orientation. The sensors connected to the left knee controller (23.sub.LK) are left knee angle, left knee force, left thigh orientation and left GRF. The sensors connected to the right hip controller (23.sub.RH) are right hip angle, right hip force, and right shoulder orientation. The sensors connected to the right knee controller (23.sub.RK) are right knee angle, right knee force, right thigh orientation and right GRF. Each of these controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) periodically receives the information from the relevant sensors and stores said sensor information in the local global data base. Additionally, each of the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) periodically sends said sensor information through the multimaster communication means (3). Further additionally, each of the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) collects from the multimaster communication means (3) the sensor information provided by other controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) and stores it in the corresponding memory (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH). The global data base in each of the memories (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH) of the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) is thereby periodically updated, i.e. the global data base of each of the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) has essentially the same information at any moment.

[0121] Therefore, each of said controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) can calculate the relevant trajectory based on the information stored in the corresponding memory (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH) and still ensure that the trajectories of all powered joints are coordinated to render a natural gait. In particular, once each global data base of each of the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) is updated, any suitable method is used for comparing the values of the global data base with reference values associated to each walking phase. Walking phases are, e.g. Stopped, Loading Response, Mid-Stance, Terminal Stance, Pre-Swing, Initial Swing, Mid Swing, Terminal Swing. Each of these phases are coincident for joints of the same leg while being out of phase with respect to the opposite leg. That is, when the right leg is in the Stance phase, the left leg is in the Swing phase (unless when both are Stopped). For each joint, the trajectory between a phase and the next phase is calculated by the controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of the module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) corresponding to said joint. The trajectory is calculated using a suitably trained Central Pattern Generator algorithm as disclosed in detail below. By maintaining the global data base of each controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) updated, synchronism between joints is ensured.

[0122] FIG. 7b shows a full exoskeleton (1) comprising all four of the modules disclosed in the present application. In this case, each controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) is connected to the relevant sensor and the information provided by those sensors is available in the corresponding global database as shown in FIG. 7a.

[0123] FIG. 8b shows a partial exoskeleton (1) comprising only the two hip modules (2.sub.RH, 2.sub.LH) and also the lumbar support (4). In this case, knee angle and knee force are not available for any of the limbs because no knee modules (2.sub.RK, 2.sub.LK) are present. In this case, however, thigh orientation sensor and GRF sensor are connected to the corresponding hip modules (2.sub.RH, 2.sub.LH), and the information provided by those sensors is therefore available in the corresponding global data base as shown in FIG. 8a.

[0124] FIG. 9b shows a partial exoskeleton (1) comprising the left knee module (2.sub.LK) and the left hip module (2.sub.LH), as well as the lumbar support (4). In this case, as disclosed in detail above, the left knee module (2.sub.RK) is mechanically coupled to the left hip module (2.sub.RH), such that they both mechanically behave as a single part. Since no right knee or hip modules (2.sub.RK, 2.sub.RH), are present in this configuration, right hip angle, right hip force, right knee angle, right knee force, and right thigh orientation are not available. However, in this case the right shoulder orientation and right GRF are connected respectively to the left hip module (2.sub.LH) and the left knee module (2.sub.LK), and the information provided by those sensors is therefore available in the corresponding global data base as shown in FIG. 9a.

[0125] FIG. 10b shows a partial exoskeleton (1) comprising the right and left knee modules (2.sub.RK, 2.sub.LK) Since no hip module (2.sub.RH, 2.sub.LH) is present, no lumbar support (4) is needed and no right shoulder orientation sensor is needed. The knee modules (2.sub.RK, 2.sub.LK) are then connected to the respective knee angle sensors, knee force sensors, thigh orientation sensors and GRF sensors, and the information provided by those sensors is therefore available in the corresponding global data base as shown in FIG. 10a.

[0126] FIG. 11 shows a partial exoskeleton (1) comprising only the left hip module (2.sub.LH) and, naturally, the lumbar support (4). In this case, the left hip module (2.sub.LH) is connected to the right GRF sensor and to the right shoulder orientation sensor, as well as to the left thigh orientation sensor and the left GRF sensor. The left hip module (2.sub.LH) is also connected to the left hip angle sensor, the left hip force sensor and the left shoulder orientation sensor. The information provided by these sensors is therefore available in the corresponding global data base as shown in FIG. 11a.

[0127] FIG. 12b shows a partial exoskeleton (1) comprising only the left knee module (2.sub.LK). Since no right knee module (2.sub.RK) is present, the left knee module (2.sub.LK) is connected to the right knee angle sensor, the right knee force sensor, the right thigh orientation sensor and the right GRF sensor. The information provided by these sensors is therefore available in the corresponding global data base as shown in FIG. 12a.

[0128] FIG. 13 schematically shows the control loop carried out by the exoskeleton (1) of the invention for ensuring a natural and coordinated gait between all modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH). First, the information from the sensors is gathered and provided to the multimaster communication means (3), whereby each module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) can receive the information and store it in the corresponding global database. The information in the global data base store in the memory (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH) of each of the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) is therefore updated at all times. Further, should a particular module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) not be present in a particular exoskeleton configuration, and should the information provided by a sensor belonging to said module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) be essential for calculating the trajectories of the powered joints of other modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) present in said particular exoskeleton configuration, then said sensor is connected to one of said other modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) present in the particular exoskeleton configuration. Then, the controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of each of the modules gathers from the relevant memory (5.sub.RK, 5.sub.LK, 5.sub.RH, 5.sub.LH) the information required for calculating the trajectory of the corresponding powered joint. Said trajectory is calculated and, thereafter, an algorithm intended to determine how much force needs to be transmitted to the powered joints depending on the force exerted by the patient is executed. Algorithms of this type are known in the art. Finally, a setpoint is sent to the relevant motor driver. This process is carried out periodically, thus ensuring coordination between the powered joints included in the particular exoskeleton (1) configuration for rendering a natural gait.

[0129] FIG. 14 schematically shows the connections between a particular controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) and the remaining components of the exoskeleton (1). This figure further shows the processor of the controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) receiving information from the patient or the operator of the exoskeleton (1) by means of a keyboard or an app. The controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) further receives the information from the relevant sensors. The controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) is in communication with the multimaster communication means (3), and the controllers (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) belonging to the rest of the modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) are also connected to the multimaster communication means (3). The processor is further connected to the relevant motor driver for sending the calculated setpoint needed for the powered joint to follow the desired trajectory.

[0130] In parallel, a safety processor gathers the information provided by current, voltage and temperature sensors connected to the motor of the relevant powered joint for detecting any malfunction. In particular, the values obtained by the current, voltage and temperature sensors are compared with predetermined values indicative of malfunction, e.g. abnormally high motor current is usually caused by a blocked motor. In that case, the controller (23.sub.RK, 23.sub.LK, 23.sub.RH, 23.sub.LH) of the module (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH) having a damaged motor commands a fail-safe routine for all modules (2.sub.RK, 2.sub.LK, 2.sub.RH, 2.sub.LH), i.e. commands each powered joint to slowly move to an initial or standby position.

Description of a Particularly Preferred Central Pattern Generator Algorithm

[0131] The generation of the angular trajectory in each exoskeleton joint is carried out in each module independently, but taking into account information of the other modules in the loop. Each module has its own pattern generator that relates with the rest of the modules forming a group of nodes that are able to create rhythmic and coordinated signals used for the generation of joint trajectory, according to the Central Pattern Generators (CPG) theory. CPGs are specially suitable as a control strategy for the modular exoskeleton due to its capacity of working decentralized and distributing the processing load of the controllers. Its functioning allows the collaboration between modules, but also permits them to work independently. This means that each module programmed with the pattern generator or CPG algorithm can function in cooperation to other actuated joint modules in the network, coordinating among themselves and modifying their trajectories according to the information received from the sensors.

[0132] In the particularly preferred trajectory calculation method designed to work on the modular exoskeleton, a Hopf oscillator has been used to create a CPG associated to each module. These CPGs have been trained with the corresponding joint trajectory for the gait pattern by means of the Dynamic Hebbian learning method applied to adaptive frequency oscillators. To accomplish this, the Hopf oscillators network belonging to each actuated joint module, learn in frequency the desired trajectory, called adaptive Hopf oscillator. This means that during the training process the oscillators of the network modify their frequency (ω.sub.i), the amplitude (α.sub.i) and their phase (ϕ.sub.i) relationships to obtain the training signal. After the training process, these values (frequency, amplitude and phase) are enough to replicate the learnt signal, being able to create the pattern autonomously.

[0133] As these values are specific for each joint, both knee and hip joints need to be trained such that they use the same algorithm but changing the trained variables. The fundamental frequency is calculated so that it corresponds with the gait pattern frequency, the rest of the variables adapt their value to replicate the desired trajectory. FIGS. 15 and 16 show the adaptation of the oscillator—in solid line—to the walking pattern used as learning signals—in dashed line—while the parameters of the oscillator stabilise. The first (upper graph) and last (lower graph) seconds of the learning process are compared for both knee and hip signals. When the learning parameters converge, the oscillator works properly and is capable to replicate the learning signal, as shown in the mentioned graphs.

[0134] The implementation into each module requires the use of new parameters that modulate output signal and permit module's communication, allowing gait synchronization. Each module uses its own pattern generator with the values of amplitude (α.sub.i) and phase (ϕ.sub.i) learned in learning phase, corresponding with the biological joint that is assisted. The signal can be modulated in amplitude with an amplitude gain (Gain.sub.α) that permits varying actuated joint flexion and extension range in real time. The pattern can be modified in frequency (ω.sub.i), distinguished between stance frequency and swing frequency.

[0135] To ensure the synchronization between modules, a synchronization term (k.sub.j) is introduced. There can be such communication terms in a module as modules in the configuration. In a particularly preferred embodiment, two communication terms are shared for each module, one to assure the coordination in its own lower limb and other to assure the coordination with the opposite lower limb.

[0136] The equations that describe the joint control strategy are:

[00001]${\stackrel{.}{x}}_{\mathrm{.Math.}}=\gamma \left(\mu -r_i^2\right)x_i-{\omega }_i{y}_i+\tau \sin \left(R_i-{\varphi }_i\right)$${\stackrel{.}{y}}_0=\gamma \left(\mu -r_0^2\right)y_0+{\omega }_0{x}_0+.Math.k_j$${\stackrel{.}{y}}_{\mathrm{.Math.}}=\gamma \left(\mu -r_i^2\right)y_i+{\omega }_i{x}_i;i=1.Math.N$${\omega }_0=f\left({\omega }_{\mathrm{swing}},{\omega }_{\mathrm{stance}}\right)$${\omega }_i={\omega }_0.Math.\left(i+1\right)$$R_i=\frac{{\omega }_i}{{\omega }_0}\mathrm{sgn}\left(x_0\right){\cos }^{-1}\left(-\frac{y_i}{r_i}\right)$$k_j=f\left(x_j,y_j\right)$$Q\left(t\right)=\underset{i=0}{\overset{N}{.Math.}}{\mathrm{Gain}}_{\alpha }.Math.{\alpha }_i.Math.x_i$

[0137] Where Q is the output signal corresponding to the angular position of the joint, x.sub.i and y.sub.i are the variables that characterize Hopf oscillators in the module, x.sub.j and y.sub.j are the first oscillator's variables of one of the coupled modules, R.sub.i assures that the oscillators are in the pattern generator are in-phase, N is the number of oscillators in the pattern generator, and j is the number of modules in the exoskeleton configuration.

[0138] The term k.sub.j depends on the number of modules attached, it can be zero in case of one independent module. However, when several modules are connected, the variable achieves that the phase relation between the first oscillator of each module will be stable. The y.sub.i value is modified by the value of x.sub.j and y.sub.j, and at the same time values x.sub.i and y.sub.i modify the value of y.sub.j. These equations allow the correct operation of the modules in every configuration setting three variables: Gain.sub.α, ω.sub.swing and ω.sub.stance, that are calculated using the sensors information or the parameters introduced by the therapist. The result of the trajectories calculated by the network of CPGs in the full exoskeleton configuration is shown in FIG. 17. Changing these variables the gait pattern rhythm can be modified while at the same time keeping the synchronism, as shown in FIG. 18.