Abstract:
Neuroprosthetic device for restoring daily-life action movements of upper limbs in patients suffering from motor impairments. The neuroprosthetic device comprises several non-invasive electrodes adapted to be fixed on a patient body, in a way as to stimulate at least two separate muscles which participate to the movement execution of the upper limb, an electrical stimulation device for injecting electrical current into said electrodes and a controller unit for regulating said currents through said electrodes. The neuroprosthetic device is characterized by the fact that the controller unit comprises transducing means which are adapted to convert an input current. The input current is regulated according to the intention to execute a movement, into a plurality of electrical currents defined in a way as to generate and modulate the movement execution, in order to generate complex goal-oriented movements for performing daily-living activities.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates to a neuroprosthetic device restoring daily-life actions involving upper limbs through electrical stimulation (ES). The present invention relates in particular to a neuroprosthetic device that allows continuous modulation of a movement according to the intention of the user to perform a certain action, extending the applicability of goal-oriented therapy and constraint-induced movement therapy to severely paralyzed patients. 
       BACKGROUND OF THE INVENTION 
       [0002]    The loss of voluntary control of upper limb muscles is a widespread disability following central or peripheral nervous system lesions. The connection between the intention to perform an action and the coordinated contraction of muscles resulting in limb movements is lost. There is therefore the need to reconnect the intention of the user to the correct sequence of muscular contractions required to perform the movement. 
         [0003]    Impaired individuals, such as stroke survivors or spinal cord injured patients, need to undergo long and intense physical rehabilitation sessions in order to recover, at least partially, the lost motor functions. Given the limited availability of resources in modern worldwide healthcare institutions, patients often receive insufficient amount of physical rehabilitation. In addition, a consistent number of patients never recover upper limb functionality even after massive therapy, developing a permanent disability. It is therefore a priority to develop methods and technological solutions aiming at improving the efficiency of the overall rehabilitation processes. To date, the most effective therapy for stroke rehabilitation is the constraint induced movement therapy (CIMT) (Langhorne et al. 2009). 
         [0004]    CIMT for stroke rehabilitation is performed restraining the unaffected limb of a patient, for example using triangular bandages or a sling, therefore forcing the patient to an increased use of the affected limb. CIMT has proven its efficacy on patients with sufficient residual mobility (Wolf et al., 2006; Sirtori et al., 2009). However, this therapy cannot be applied on completely paralyzed patients. In fact, residual function is required to complete even the simplest tasks involving the unconstrained limb. Standard criteria for inclusion in CIMT require a patient to display 20 degrees of extension of the wrist and 10 degrees of extension of the fingers. Such relatively high level of motor ability is met by less than 50% of stroke patients (Taub et al., 1998). 
         [0005]    Current motor rehabilitation also relies on intensive exercise sessions, robotic rehabilitation systems or peripheral electrical stimulation of nerves and muscles. Intensive exercise sessions are usually limited by the availability of therapist time. Robotic solutions are developed to replace therapists in intensive exercises sessions. However, robotic solutions are still expensive and a limited number of units can be afforded by hospitals, if any. Most importantly, existing robotic solutions (such as InMotion ARM™, Hocoma Armeo™, etc.) only provide passive means of exercising, helping to displace patient&#39;s limbs, and are of limited use for completely paralyzed individuals. 
         [0006]    Neuroprosthetic devices have the potential of both improving current rehabilitation, by increasing therapy time, and restoring function in permanently disabled individuals. This invention relates to a neuroprosthetic system that allows patient to generate goal-oriented movements of their paralyzed limb. Embodiments of the invention could be used to perform constraint-induced movement therapy on severely paralyzed patients by actuating patient&#39;s muscles through neuromuscular electrical stimulation. 
         [0007]    Electrical stimulation of upper limbs has shown promising results in promoting voluntary upper limb function recovery (Chae et al., 1998; Alon et al., 2007; Pomeroy et al., 2009). However, in the current medical practice, electrical stimulation therapy is limited by the availability of skilled clinicians in the art and by the lack of a general consensus on how to maximize its efficacy. 
         [0008]    Various systems providing electrical stimulation therapy to restore upper limb functions have been proposed. Generally, such systems comprise several invasive or surface electrodes to convey electricity from an electrical stimulator to nerves and muscles of a user. A controller unit generates the electrical current signals Such electrical current is produced according to a predefined sequence of stimulation, or willingly by users. 
         [0009]    Several systems to restore upper limb functionality rely on electrodes implanted in the limb to deploy electrical stimulation such as the systems disclosed in Peckham et al., 1992 (U.S. Pat. No. 5,167,229), and in Fang et al., 2002 (US 2002/0188331). Both systems are controlled either by an implanted or external shoulder joystick operated by the user. 
         [0010]    Implanting the electrodes solves the problem of maintaining them placed on a specific stimulation site, but requires an expensive and risky surgery. Other systems use surface electrodes, solving the issue by mounting the electrodes on arms-mounted orthosis such as Tong et al., 2007 (US 2007/0179560) or Koeneman et al., 2004, (US 2004/0267331). However, such orthosis are usually very bulky, limiting user mobility, and cannot ensure optimal contact while performing movements, i.e. relative positions and contact area of electrodes and skin changes during use. 
         [0011]    Other proposed systems employ cheap surface electrodes, attached to the skin through adhesive conductive glue such as Popovic et al., 2004 (US 2004/0147975). However, the use of surface electrodes requires expert help for positioning said electrodes. Moreover, such standard electrodes are not adapted to guarantee stable positioning over the skin during movements. Most importantly, the glue deteriorates as time goes by favoring detachment of electrodes resulting in discomfort and pain by the users. 
         [0012]    Other solutions such as Petrovsky, 1985 (U.S. Pat. No. 4,558,704) addresses only specific functionality of the upper limbs, namely hand opening and closing. 
         [0013]    All the above cited systems either allow: 1) simply enabling or disabling the stimulation by use of a switch or button, without providing any means to modulate the stimulation; or 2) modulating the stimulation (and therefore the resulting movement) by providing to the user non-intuitive means to generate a control signal, such as shoulder joysticks. Therefore, they are not suitable to be operated by elderly or cognitive disabled individuals. 
         [0014]    A recent system disclosed by Molnar et al., 2009 (US 2009/0099627) describes a system that decodes a movement state directly from the brain of a patient and deliver a therapy accordingly. However, the system requires either implanted electrodes or relies on standard surface electrodes, incurring in the aforementioned problems of maintaining optimal placement. 
         [0015]    There is therefore the need to develop a neuroprosthetic device that can be used both as a rehabilitation and assistive technology tool to restore daily life activities involving upper limbs, providing intuitive means to modulate the movements. Moreover, such device should provide easy application of electrodes and ensure electrode placement for long period of time. Finally, to integrate the device into current medical practice it should provide means to improve and extend constraint-induced movement therapy to any type of paralyzed patient. 
       SCIENTIFIC REFERENCES 
       [0016]    Sirtori V, Corbetta D, Moja L, Gatt R, “ Constraint - induced movement therapy for upper extremities in stroke patients”,  Cochrane Database Systematic Review, 2009. 
         [0017]    Wolf S L, Winstein C J, Miller J P, Taub E, Uswatte G, Monis D, Giuliani C, Light K E, Nichols-Larsen D, “ Effect of constraint - induced movement therapy on upper extremity function  3  to  9  months after stroke”,  JAMA, 2006. 
         [0018]    Taub E, Crago J E, Uswatte G, “ Constraint - induced movement therapy: A new approach to treatment in physical rehabilitation ”, Rehabilitation Psychology, 1998. 
         [0019]    Pomeroy V M, King LM, Pollock A, Baily-Hallam A, Langhorne P, “ Electrostimulation for promoting recovery of movement or functional ability after stroke” , Cochrane Database Systematic Review, 2009. 
         [0020]    Alon G, Levitt A F, McCarthy P A, “ Functional Electrical Stimulation Enhancement of Upper Extremity Functional Recovery During Stroke Rehabilitiation: A Pilot Study” , Neurorehabilitation and neural repair, 2007. 
         [0021]    Chae J, Bethoux F, Bohinc T, Dobos L, Davis T, Friedl A, “ Neuromuscular Stimulation for Upper Extremity Motor and Functional Recovery in Acute Hemiplegia” , Stroke, 1998. 
         [0022]    Langhorne, P, Coupar F, Pollock A. “ Motor recovery after stroke: a systematic review” . The Lancet Neurology, 2009 
       SUMMARY OF THE INVENTION 
       [0023]    An aim of the invention is thus to provide a non-invasive device that restores daily life actions involving a paralyzed upper limb 
         [0024]    This aim and other advantages are achieved by a device comprising the features of claim  1 . 
         [0025]    This aim is achieved in particular by a neuroprosthetic device comprising several non-invasive electrodes adapted to be fixed on the body of the user. This device also comprises an electrical stimulation unit for generating electrical currents that flow through aforementioned electrodes causing muscular contractions and a controller unit for regulating said currents. This controller unit comprises an intention transducing unit which is adapted to convert an input current, regulated according to the intention of the user to execute the desired action, into a plurality of electrical currents being defined in a way as to generate and modulate limb movements, accordingly. Importantly, said movements are goal-oriented, and can restore basic activities of daily living and goal-oriented tasks. Furthermore the controller unit is adapted to generate electrical currents that mitigate muscular fatigue when the device is not actively operated by the user. 
         [0026]    A second aim of the invention is to provide a neuroprosthetic device allowing an easy implementation of the constraint-induced movement therapy for partially or completely paralyzed patients. 
         [0027]    This aim is achieved by a device comprising the features of claims  6  and  7 . 
         [0028]    This aim is achieved in particular by a neuroprosthetic device comprising a constraining orthosis blocking the healthy limb adapted to sustain and allow easy attachment and detachment of the controller and stimulating units. 
         [0029]    A third aim of the invention is to provide an intuitive device that can be easily operated by elderly or cognitively impaired individuals. 
         [0030]    This aim is achieved by a device comprising the features of claims  2 ,  3 ,  4  and  5 . 
         [0031]    This aim is achieved in particular by a neuroprosthetic device that transduces the intention to perform a certain action into a one dimensional control variable for the controller unit. The intention can be transduced by a variety of means such as the rotation of a knob, electromyography signal extracted from a body part, touch sensors located in contact with a finger of the user, eye movements or body tracking systems. The neuroprosthetic device is characterized by the fact that for a given action the modulation of movement is achieved through modulation of said one dimensional control variable. 
         [0032]    A fourth aim of the invention is to provide an easy to mount device that is well adapted to fit the morphology of the user, thus increasing the comfort of usage. 
         [0033]    This aim is achieved by a device comprising the features of claims  8  and  9 . 
         [0034]    This aim is achieved in particular by embedding multiple electrodes into adhesive supports, thus minimizing the number of operations required to correctly place the electrodes on the limbs. Also, the wires connecting each electrode to the stimulation unit are grouped into a single flexible wire running through the different adhesive supports, thus avoiding dangling cables. The adhesive supports can be easily placed through the aid of a semi-rigid orthosis, acting as a user-customized placement system. Another way in which this aim can be achieved is by using means to deposit a layer of conductive polymer on the skin of the patient, allowing therapist to “draw” custom electrodes on the patient&#39;s skin. Such conductive polymer can cure (solidify) in a relatively fast time and be easily detached if needed from the skin, for example being washable. The polymer can be applied for example by a marker. 
         [0035]    A fifth aim of the invention is to provide a neuroprosthetic device that can replicate movements of a limb of other users, enabling parallel reproduction of movements on several devices or allowing mirror therapy on the same user 
         [0036]    This aim is achieved by a device comprising the features of claims  5 ,  10  and  11 . 
         [0037]    This aim is achieved in particular by a neuroprosthetic device comprising a controller unit adapted to receive wirelessly stimulation commands. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0038]    The present invention will be better understood with the help of the following description illustrated by the figures, wherein: 
           [0039]      FIG. 1  shows a simplified block diagram of one embodiment of the invention. 
           [0040]      FIGS. 2A, 2B and 2C  shows the neuroprosthetic device according to a preferred embodiment of the invention. 
           [0041]      FIG. 3  shows the neuroprosthetic device according to another preferred embodiment of the invention. 
           [0042]      FIG. 4  shows the neuroprosthetic device according to another preferred embodiment of the invention. 
           [0043]      FIG. 5  shows an electrode support according to an embodiment of the invention. 
           [0044]      FIG. 6  shows the neuroprosthetic device according to another preferred embodiment of the invention allowing electrically-assisted constraint-induced movement therapy. 
           [0045]      FIG. 7  shows an intention transducing unit in the form of a rotating knob, according to an embodiment of the invention. 
           [0046]      FIG. 8 a    shows the electrode support montage resulting in one of the actions provided by one of the embodiments of the invention.  FIG. 8 b    shows a detailed view of the muscles involved during the electrical stimulation and  FIGS. 8 c , 8 d  and 8 e    shows the action produced by the stimulation. 
           [0047]      FIG. 9 a    shows the electrode support montage resulting in one of the actions provided by one of the embodiments of the invention.  FIG. 9 b    shows a detailed view of the muscles involved during the electrical stimulation and  FIGS. 9 c  and 9 d    shows the action produced by the stimulation. 
           [0048]      FIGS. 10 a , 10 c  and 10 d    shows the electrode support montage resulting in one of the actions provided by one of the embodiments of the invention.  FIG. 10 b    shows a detailed view of the muscles involved during the electrical stimulation.  FIGS. 10 e  and 10 f    shows the action produced by the stimulation. 
           [0049]      FIG. 11 a    shows the electrode support montage resulting in one of the actions provided by one of the embodiments of the invention.  FIG. 11 b    shows a detailed view of the muscles involved during the electrical stimulation and  FIG. 11 c  and 11 d    shows the action produced by the stimulation. 
           [0050]      FIG. 12 a    shows the electrode support montage resulting in one of the actions provided by one of the embodiments of the invention.  FIG. 12 b    shows a detailed view of the muscles involved during the electrical stimulation and  FIGS. 12 c  and 12 d    shows the action produced by the stimulation. 
           [0051]      FIG. 13  shows an electrode support configuration for another embodiment of the invention. 
           [0052]      FIG. 14  shows a fast curing conductive polymer being applied using a suitable marker on the skin of a user.  FIG. 14 a    shows the application of the conductive polymer on the skin.  FIG. 14 b    shows the insertion of a conductive lead into the conductive polymer providing connection to the electrical stimulator.  FIG. 14 c    shows the final cured electrode after the conductive polymer solidified and embedded the lead. 
           [0053]      FIG. 15  shows the neuroprosthetic device according to another preferred embodiment of the invention, allowing parallel therapy on several patients through body tracking and electrical stimulation. 
       
    
    
     LIST OF FIGURE LABELS 
       [0054]      1 . Electrodes 
         [0055]      2 . Electrical stimulator 
         [0056]      3 . Controller unit 
         [0057]      4 . Input signal 
         [0058]      5 . Intention transducer 
         [0059]      6 . Plurality of electrical currents 
         [0060]      7 . Cylindrical casing 
         [0061]      8 . Rotating knob 
         [0062]      9 . Constraint orthosis 
         [0063]      10 . Docking station 
         [0064]      11 . Electrode adhesive patch 
         [0065]      12 . Other casing 
         [0066]      13 . Master controller 
         [0067]      14 . 3d camera based tracking system 
         [0068]      15 . Target user 
         [0069]      16 . Available users in range 
         [0070]      17 . Finger mounted intention detector 
         [0071]      18 . EMG bracelet 
         [0072]      19 . Electrode attachment plug 
         [0073]      20 . Conductive area 
         [0074]      21 . Adhesive support with multiple electrodes 
         [0075]      22 . Multi-channel plug for connection with other patches 
         [0076]      23 . Wiring 
         [0077]      24 . Movement Controller and constraint 
         [0078]      25 . Arm Braces 
         [0079]      26 . Locking mechanism 
         [0080]      27 . Buttons 
         [0081]      28 . Screen 
         [0082]      29 . Knob parts in relief 
         [0083]      30 . Biceps brachii 
         [0084]      31 . Brachialis 
         [0085]      32 . Flexor digitorum superficialis 
         [0086]      33 . Narrow adhesive section 
         [0087]      34 . Extensor indicis proprii 
         [0088]      35 . Subspinous fossa 
         [0089]      36 . Pectoral minor 
         [0090]      37 . Pectoral major 
         [0091]      38 . Deltoid 
         [0092]      39 . Flexor pollicis longus 
         [0093]      40 . Fast curing polymer with conductive particles 
         [0094]      41 . Marker 
         [0095]      42 . Lead to electrical stimulator 
         [0096]      43 . Adjustable length part 
         [0097]      44 . electrode biceps 
         [0098]      45 . electrode flexor digitorum superficialis 
         [0099]      46 . electrode distal extensor indicis proprium 
         [0100]      47 . electrode proximal extensor indicis proprium 
         [0101]      48 . electrode distal subspinous fossa 
         [0102]      49 . electrode proximal subspinous fossa 
         [0103]      50 . electrode proximal flexor digitorum superficialis 
         [0104]      51 . electrode distal pectoral minor 
         [0105]      52 . electrode ventral pectoral major 
         [0106]      53 . electrode ventral portion deltoid 
         [0107]      54 . electrode lateral proximal deltoid 
         [0108]      55 . electrode distal flexor pollicis longus 
         [0109]      56 . electrode distal ventral flexor digitorum superficialis 
         [0110]      57 . electrode distal extremity deltoid 
         [0111]      58 . distal pectoralis major 
         [0112]      59 . ventral distal deltoid 
         [0113]      60 . Buttons on hand worn controller 
         [0114]      61 . Rotating knob on hand worn controller 
         [0115]      62 . Generic stimulation or sensing connection wire 
         [0116]      63 . Generic stimulation or sensing multi-channel plug 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0117]      FIG. 1  shows the simplified block diagram of the neuroprosthetic device comprising several non-invasive electrodes  1 , an electrical stimulation unit  2  and a controller unit  3  adapted to convert an input current  4  generated by an intention transducer unit  5  into a plurality of electrical currents  6 . The controller unit  3  internally processes the input current  4  converting it into stimulation commands for the electrical stimulator  2 , said stimulator eventually generating a plurality of electrical current  6 . 
         [0118]    In a preferred embodiment, illustrated in  FIG. 2 a   , the neuroprosthetic device comprises a cylindrical casing  7  fixed on a rigid, semi-rigid or soft orthosis  9 . The cylindrical casing  7  embeds the electrical stimulator  2 , the controller unit  3  and an intention transducing unit  5  in the form of a rotating knob  8 , fixed on top of the cylindrical casing  7 . 
         [0119]    The preferred embodiment illustrated in  FIG. 2 a    allows delivering constraint-induced movement therapy to users of the neuroprosthetic device, thus providing a device for performing a therapy that we named ‘electrically-assisted constraint-induced movement therapy’ (EA-CIMT). 
         [0120]    Constraint-induced movement therapy is a rehabilitation approach mainly used for brain stroke survivors. Concerning upper limbs, it consists in immobilizing the healthy side of the body therefore forcing patients to train their affected side through exercises. This therapy requires a certain degree of residual movement in the impaired limb, and currently cannot be performed on completely paralyzed patients. EA-CIMT overcomes this limitation by allowing patients, even completely paralyzed, to control movements of the affected side of the body with the healthy side of the body. The fact that physical movement controllers are operated using the healthy limb, for example with the unaffected hand, implies that such devices serve both as movement controllers and as constraining means. 
         [0121]    The preferred embodiment of  FIG. 2 a    allows delivering EA-CIMT to completely paralyzed patients, even immediately after the stroke. 
         [0122]    The ergonomics of the cylindrical casing  7  facilitates knob rotation by a constrained healthy limb. Moreover, choosing a knob as an intention transducing unit allows intuitive interaction also by elderly people. 
         [0123]    In another preferred embodiment, illustrated in  FIG. 2 b   , the cylindrical casing  7  only embeds the controller unit  3  while the electrical stimulator  2  is docked to another supporting structure of the orthosis. 
         [0124]    To accommodate weight or space limitations defined by the application, the controller unit  3  and/or the electrical stimulator  2  can be embedded together or not in the cylindrical casing  7 . 
         [0125]      FIG. 2 c    shows the orthosis  9  without any attached cylindrical casing. The orthosis  9  allows easy attachment and detachment of the cylindrical casing  7  by means of the docking means  10 . As illustrated in  FIG. 2 b   , the orthosis  9  can be adapted to embed several docking means  10 , allowing the customization of the position of the cylindrical casing  7  according to user comfort. 
         [0126]    In a preferred embodiment, illustrated in  FIG. 3 , the neuroprosthetic device comprises the casing  12 , adapted to be worn on the body, which includes the electrical stimulator  2 , the controller unit  3  and means adapted to communicate wirelessly with an intention transducing unit  5  in the form of a finger mounted touch sensitive device  17 . 
         [0127]    One of the current problems of wearable devices is their intrusiveness and visibility, resulting in reduced comfort and ease-of-use. The intention transducer unit  5  in the form of a finger mounted touch sensitive device  17  is therefore designed to be worn on a single finger, preferably the index, and operated with another finger, preferably the thumb. In addition, the choice of device ergonomics, colors and materials is made in order to minimize intrusiveness and visibility. 
         [0128]    In another preferred embodiment, illustrated in  FIG. 4  the intention transducer unit  5  has the form of an arm mounted device  18  to record and process electromyography signals. 
         [0129]    The forearm mounted device  18  is minimally intrusive and allows fine object manipulation in patients having residual muscular activity in the forearm, thus optimizing ease-of-use. 
         [0130]    Using residual muscular activity in the arm or forearm, decoded through the arm mounted device  18 , is of special interest for rehabilitation settings, since an automatic system can be adapted to reinforce beneficial muscular patterns and discard abnormal responses while trying to accomplish a certain action. Arm mounted device  18  can be placed on different positions of the arm and the forearm in order to record EMG activity of different muscle groups, accommodating specific patient&#39;s needs. 
         [0131]    As illustrated in  FIG. 5 , the conductive surface  20  of electrodes  1  is in contact with the skin of the user. Electrodes  1  are grouped onto an insulating adhesive support  21  embedding multiple electrodes  1 . Electrodes  1  are connected through a multi-channel plug  19  to the electrical stimulator  2 , through the wiring  23 . 
         [0132]    Grouping the electrodes into a single disposable support  21  allows easy and fast replacement of multiple electrodes, minimizing the time needed to setup the neuroprosthetic device on a user. 
         [0133]    Adhesive support  21  can be produced in different sizes in order to accommodate a variety of upper limb morphologies. In addition, electrodes  1  are placed on the supports in pre-defined positions in order to allow the generation of the desired set of actions. 
         [0134]    The multi-channel plug  19  allows easy connection of all the electrodes  1  to the electrical stimulator  2 , minimizing montage time. Furthermore every disposable support can be connected by means of other multi-wire plugs  22  to electrodes on different adhesive supports. 
         [0135]    The preferred embodiments of  FIG. 6  facilitate prolonged EA-CIMT on paralyzed patients. 
         [0136]      FIG. 6 a    illustrates an intention transducer unit  5  in the form of a wearable controller  24  that is fixed on the healthy limb through forearm-mounted braces  25 . The rigid orthosis  9  is adapted to embed wiring and allow the placement of electrodes on the patient&#39;s back. Moreover, the orthosis contains the wiring necessary to provide electrical connectivity between the wearable controller  24  and the electrodes  1 , which are embedded into a supporting adhesive patch  11 . Said adhesive patch  11  maintains the system in the desired positions and includes wiring to connect the electrodes. 
         [0137]    In another preferred embodiment, the wearable controller  24  communicates wirelessly with at least one electrical stimulator  2  wired to stimulation electrodes  1 . 
         [0138]      FIG. 6 b    illustrates an embodiment of the wearable movement controller  24  having forearm-mounted braces  25 , and adjustable length in order to be fixed on patients having different forearm length. Furthermore, the part with adjustable length  43  allows the user to displace the movement controller  24 , freeing the healthy hand for use. Said wearable movement controller  24  has buttons  60  that allow users to select the desired movement with the thumb and a rotating knob  61  that allows users to modulate the selected movement according to their will. Said rotating knob  61  acts as rotating knob  8  shown in  FIGS. 2 a    and  2   b.    
         [0139]      FIG. 6 c    illustrates an embodiment where the healthy arm weight is supported through a locking system  26  adapted to mechanically stabilize the relative angle between the proximal and distal portions of the arm. Said locking system  26  is fixed to the body through arm-braces  25 . 
         [0140]    The rigid orthosis  9  and locking system  26  are adapted to constrain and to support the healthy limb, thus avoiding postural fatigue. Moreover, the orthosis internally contains the appropriate wiring to provide electrical connectivity between the wearable controller  24  and the electrodes  1 , which are embedded into a supporting adhesive patch  11  that maintains the electrodes in the desired positions and includes wiring to connect the electrodes. 
         [0141]      FIG. 6 d    further illustrates an embodiment of a 2-states adjustable locking mechanism  26  either allowing rotations of the elbow joint or providing mechanical support against gravity. 
         [0142]      FIG. 7  illustrates how the intention transducing unit  5 , in the form of a rotating knob  8 , is embedded into a cylindrical casing  7  comprising the controller unit  3 . Said rotating knob  8  was also illustrated in  FIG. 2 a , 2 b   ,  6   c.    
         [0143]    Buttons  27  located on the side walls of the cylindrical casing  7  allow the user to select the desired action. Buttons  27  also allows switching on and off the device and select additional functionalities offered by the device and visualized on the screen  28 . 
         [0144]    The rotation of knob  8  is transformed into an electrical signal by means of a mechanical to electrical signal transducer, for example a rotary encoder, magnetic encoder or optical device. Such signal is transmitted to the controller unit  3 . 
         [0145]    The knob  8  can include parts in relief  29  to facilitate handling and rotation of the knob, especially for elderly users. 
         [0146]    The controller unit  3  is connected to an internal or external electrical stimulator  2 . In the case of embedding an internal electrical stimulator  2  the controller unit  3  is connected through a multichannel plug to the electrodes  1 . 
         [0147]    The intention transducing unit  5  provides connectivity to external devices through wires or wirelessly. 
         [0148]    The intention transducing unit  5  is powered by a rechargeable battery embedded in the cylindrical casing  7 . The battery can be recharged through the power plug. 
         [0149]    The controller unit  3  comprises a microcontroller or microprocessor to perform internal computation and drive the electrical stimulator  2 , transforming signals received from intention transducing unit  5  to input signals for the electrical stimulator  2 . 
         [0150]      FIG. 8 a    illustrates an electrodes support  21  manufactured to embed and correctly place on the body electrodes  44  and  45 . 
         [0151]      FIG. 8 b    clarifies the muscles electrically stimulated by the electrodes embedded in adhesive support  21 . Electrode support  21  is adapted to maintain electrode  44  fixed on top of the ventral, proximal side of the biceps brachii muscle  30 , also involving the brachialis muscle  31  (to obtain elbow flexion and supination); and electrode  45  on the distal extremity of the flexor digitorum superficialis muscle  32  (to obtain fingers flexion and palmar hand grasping). Electricity is injected through bipolar montage over electrodes  44  and  45  as to jointly stimulate biceps and fingers flexor muscles. 
         [0152]    Electrodes  44  and  45  allow stimulation with electrical currents, for example with a rectangular waveform, wherein said waveform has a frequency between 15 and 60 Hz, a pulse width between 150 and 500 us and a current intensity between 0 and 50 mA to induce harmonious movement to grasp and bring objects located in front of the body to the mouth, as shown in  FIG. 8 c    (starting position),  FIG. 8 d    (intermediate position) and  FIG. 8 e    (final position). 
         [0153]    The electrical connectivity between electrodes  44  and  45  is ensured by a generic stimulation or sensing connection wire  62  embedded into the adhesive support  21 . 
         [0154]    Electrode support  21  comprises a narrow adhesive section  33  running on the posterior side of the forearm, over the line defined by the ulna bone connecting the elbow to the wrist joints. 
         [0155]    Adhesive section  33 , maintaining the generic stimulation or sensing connection wire  62  attached to the arm, prevents it from being unwillingly pulled during the execution of daily life actions. 
         [0156]    The support can be connected to the electrical stimulator  2  by means of a generic stimulation or sensing multi-channel plug  63 . 
         [0157]      FIG. 9 a    illustrates an electrodes support  21  manufactured to embed and correctly place on the body electrodes  46  and  47 . 
         [0158]      FIG. 9 b    clarifies the muscles electrically stimulated by the electrodes embedded in support  21 . Electrodes support  21  is adapted to maintain electrode  47  on the proximal extremity of the extensor indicis proprium muscle  34  and electrode  46  on the distal extremity of the extensor indicis proprium muscle  34  (to obtain index extension). Electricity is injected through bipolar montage over electrodes  46  and  47  as to stimulate the extensor indicis proprium muscle. 
         [0159]    Electrode  46  and  47  allow stimulation with electrical currents, for example with a rectangular waveform, wherein said waveform has a frequency between 15 and 60 Hz, a pulse width between 150 and 500 us and a current intensity between 0 and 40 mA to induce harmonious movement to extend the index and point at objects located everywhere in space. For example  FIG. 9 c    shows the starting position of the action and  FIG. 9 d    the ending position resulting in the execution of the action. 
         [0160]      FIGS. 10 a , 10 c  and 10 d    illustrate electrode supports  21   a  and  21   b  manufactured to embed and correctly place on the body electrodes  44 ,  45 ,  48 ,  49 . 
         [0161]      FIG. 10 b    clarifies the muscles electrically stimulated by the electrodes embedded in support  21   a . One electrode support  21   a  is adapted to maintain electrode  44  on the ventral, proximal side of the biceps brachii muscle  30 , also involving the brachialis muscle  31  (to obtain elbow flexion and supination) and electrode  45  on the flexor digitorum superficialis muscle  32  (to obtain fingers flexion and palmar hand grasping). Electricity is injected through bipolar montage over electrodes  44  and  45  as to separately stimulate the biceps and fingers flexor muscles. 
         [0162]    Another electrode support  21   b  is adapted to maintain electrode  48  on the distal extremity of the sub spinous fossa  35  and another electrode  49  on the proximal extremity of the sub spinous fossa  35  (to obtain external shoulder rotation). Electricity is injected through bipolar montage over electrodes  48  and  49 . 
         [0163]    Electrodes  44  and  45  allow stimulation with electrical currents, for example with a frequency between 15 and 60 Hz, a pulse width between 150 us and 500 us and a current intensity between 0 and 50 mA. 
         [0164]    Electrodes  48  and  49  allow stimulation with electrical currents, for example with a frequency between 15 and 60 Hz, a pulse width between 150 us and 500 us and a current intensity between 0 and 60 mA. 
         [0165]    The electrical parameters of currents applied on electrodes  44 ,  45 ,  48 ,  49  are designed to induce harmonious movement to pass objects from a position in front of the body to a position far from the body, on the same hemi-space of the stimulated limb as shown in  FIG. 10 e    (starting position) and  FIG. 10 f    (final position). 
         [0166]    Electrode supports  21   a  might comprise a narrow adhesive section  33   a  running on the posterior side of the elbow between the lateral epicondyle and the olecranon. 
         [0167]    Adhesive section  33   a , maintaining the generic stimulation or sensing connection wire  62  attached to the arm, prevents it from being unwillingly pulled during the execution of daily life actions. 
         [0168]    Electrode support  21   b  might comprise an elongated adhesive portion  33   b  running over the acromion stabilizing support  21   b  and allowing prolonged usage during the day. 
         [0169]    Electrical connectivity between the electrical stimulator  2  and the electrodes support  21   a  is allowed by wiring connected to generic stimulation or sensing multi-channel plug  63   a . Electrical connectivity to the electrode support  21   b  is established by connecting the generic stimulation or sensing multi-channel plug  63   b  by means of proper wiring. 
         [0170]      FIG. 11 a    illustrates electrode supports  21   a  and  21   b  manufactured to embed and correctly place on the body electrodes  44 ,  50 ,  51 ,  52 ,  53 ,  54 . 
         [0171]      FIG. 11 b    clarifies the muscles electrically stimulated by the electrodes embedded in supports  21   a  and  21   b . One Electrode support  21   a  is adapted to maintain electrode  44  on the ventral, proximal side of the biceps brachii muscle  30 , also involving the brachialis muscle  31  (to obtain elbow flexion and supination) and another electrode  50  on the lateral side of the on the flexor digitorum superficialis muscle  32  (to obtain fingers flexion and palmar hand grasping). Electricity is injected through bipolar montage over electrodes  44  and  50  as to jointly stimulate the biceps and fingers flexor muscles. 
         [0172]    Another electrode support  21   b  is adapted to maintain electrode  51  on the distal extremity of the pectoralis minor  36 , electrode  52  on the ventral portion of the pectoralis major  37  in correspondence of the ventral part of the underlying pectoralis minor  36  (to obtain internal shoulder rotation and arm flexion crossing the median plane), electrode  53  on the ventral portion of the deltoid muscle  38  and electrode  54  on the lateral proximal side of the deltoid muscle  38 , below the clavicle (to support internal shoulder rotation and arm flexion on the median plane). Electricity is injected through a bipolar montage over electrodes  51 ,  52  and  53 ,  54  as to separately stimulate the pectoralis and deltoid muscles. 
         [0173]    Electrodes  44 ,  50 ,  51 ,  52 ,  53 ,  54  allow stimulation with electrical currents, for example with a rectangular waveform, wherein said waveform has a frequency between 15 and 60 Hz, a pulse width between 150 us and 500 us and a current intensity between 0 to 60 mA. 
         [0174]    The electrical parameters of currents applied on electrodes  44 ,  50 ,  51 ,  52 ,  53 ,  54  are designed to induce a harmonious movement to pass objects from a position in front of the body to a position far away towards the opposite side of the body as shown in  FIG. 11 c    (starting position) and  FIG. 11 d    (final position). 
         [0175]    Electrode support  21   a  comprises one narrow adhesive section  33   a  running from the pectoralis major  37  towards the shoulder. Adhesive section  33   a  has a shape adapted to fit and hold to the clavicle, ensuring that the placement of electrode support  21   a  is stable during complex movements. 
         [0176]    Another electrode support  21   b  comprises one narrow adhesive section  33   b  running from the shoulder to the armpit. Adhesive section  33   b , maintains wiring between electrode support  21   b  attached to the arm, preventing it from being unwillingly pulled during the execution of daily life actions. 
         [0177]      FIG. 12 a    illustrates electrode supports  21  manufactured to embed and correctly place on the body electrodes  53 ,  54 ,  55 ,  56 ,  57 ,  58 . 
         [0178]      FIG. 12 b    clarifies the muscles electrically stimulated by the electrodes embedded in support  21 . One electrode support  21  is adapted to maintain electrode  55  on the distal portion of the flexor pollicis longus muscle  39 , electrode  56  on the ventral portion of the flexor digitorum superficialis muscle  32  (to obtain finger flexion into a palm and thumb grasp). Another electrode support  21  is adapted to maintain electrode  54  on the ventral, distal side of the deltoid  38 , electrode  57  on the distal extremity of the deltoid  38  (to obtain arm flexion on the median plane), electrode  53  on the ventral portion of the deltoid  38 , electrode  58  on the distal extremity of the pectoralis major  37 , under the clavicle (to support and stabilize arm rotation). Electricity is injected through bipolar montages over electrodes  53 ,  57  and  55 ,  56  and  54 ,  58  as to separately stimulate fingers flexors, pectoralis and deltoid muscles. 
         [0179]    Electrodes  53 ,  54 ,  55 ,  56 ,  57 ,  58  allow stimulation with electrical currents, for example with a rectangular waveform, wherein said waveform has a frequency between 15 and 60 Hz, a pulse width between 150 us and 500 us and a current intensity between 0 and 50 mA. 
         [0180]    The electrical parameters of currents applied on electrodes  53 ,  54 ,  55 ,  56 ,  57 ,  58  are designed to induce a harmonious movement to grasp an object in front of the subject and lift it on its median plane, frontally as shown in  FIG. 12 c    (starting position) and  FIG. 12 d    (final position). 
         [0181]      FIG. 13  shows several electrodes supports  21  adapted to embed electrodes  1  according to their spatial proximity on the body, in one of the embodiments of the invention. 
         [0182]    Embedding the electrodes supports  21  on a surface according to their spatial proximity reduces the number of patches to be applied to the body, thus increasing the ease-of-use of this embodiment of the invention. 
         [0183]    Other configurations are possible, for example reducing the number of electrodes to obtain a smaller set of movements. 
         [0184]    In a preferred embodiment, illustrated in  FIG. 13 , the casing  12  embeds the controller unit  3  and the electrical stimulator  2 . The controller unit  3  is adapted to receive wirelessly stimulation commands from a master controller  13 . The master controller  13  collects and processes data from body tracking system, for example a 3D camera-based tracking system  14 . 
         [0185]      FIG. 14 a    shows the application of the conductive polymer  40  on the skin of a user by using a marker  41 . Such conductive polymer can be realized for example using silicon-derived fast curing polymers mixed with conductive particles, for example carbon particles, metal particles or other bio-compatible conductive particles or small conductive structures. The polymer can have other properties to facilitate detachment, as for example being washable or degrade autonomously after a defined number of hours. The marker  41  is only one possible way to apply the polymer on the skin, other examples includes brushes or pencils. 
         [0186]      FIG. 14 b    shows the insertion of a conductive lead  42  into the conductive polymer providing connection to the electrical stimulator.  FIG. 14 c    shows the final cured electrode after the conductive polymer  40  solidified and embedded the lead  42 . 
         [0187]    In most clinical settings, physical therapy is often performed by groups of patients and one or two physical therapists. Given the complexity of current electrical stimulation devices and the need to program each device for a specific patient, it is currently impossible to perform group exercises interactively. The embodiment illustrated in  FIG. 15  enables group physical therapy, for example by replicating the movements of the arm of the therapist on all the patients attending the session. 
         [0188]    In a preferred embodiment, movements of one side of the body are replicated on the other side of the body, allowing mirror-like replication of movements. 
         [0189]    In alternative embodiments, the body tracking system can be implemented with wearable gyroscopes or accelerometers adapted to communicate with the master controller  13 . 
         [0190]    The master controller  13  broadcasts stimulation commands to every controller unit  3  in range, replicating the tracked movements of a target user  15  on all other users in range  16 .